Science.gov

Sample records for strike point position

  1. Strike Point Control on EAST Using an Isoflux Control Method

    NASA Astrophysics Data System (ADS)

    Xing, Zhe; Xiao, Bingjia; Luo, Zhengping; L. Walker, M.; A. Humphreys, D.

    2015-09-01

    For the advanced tokamak, the particle deposition and thermal load on the divertor is a big challenge. By moving the strike points on divertor target plates, the position of particle deposition and thermal load can be shifted. We could adjust the Poloidal Field (PF) coil current to achieve the strike point position feedback control. Using isoflux control method, the strike point position can be controlled by controlling the X point position. On the basis of experimental data, we establish relational expressions between X point position and strike point position. Benchmark experiments are carried out to validate the correctness and robustness of the control methods. The strike point position is successfully controlled following our command in the EAST operation. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2012GB105000 and 2014GB103000)

  2. Strike Point Control for the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    Kolemen, E.; Gates, D. A.; Rowley, C. W.; Kasdin, N. J.; Kallman, J.; Gerhardt, S.; Soukhanovskii, V.; Mueller, D.

    2010-07-09

    This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving "snowflake" divertor configuration in NSTX.

  3. Equilibrium and vertical-instability considerations for vertical strike-point shifts on the ITER divertor targets

    NASA Astrophysics Data System (ADS)

    Kolesnikov, R. A.; Bulmer, R. H.; LoDestro, L. L.; Casper, T. A.; Pitts, R. A.

    2013-08-01

    The study of operation with raised strike points on the first ITER divertor target plates is motivated by the need to gain experience with operation with strike points on tungsten (W) surfaces during the non-active phases (in the case of an initial carbon fibre composite (CFC)/W divertor); or (if ITER begins with a full-W divertor), to gain experience with plasma control and transients while operating with raised strike points to avoid damaging the baseline strike regions in preparation for the nuclear phase, and to provide a means for operation should damage occur in the baseline strike zone. For operation with raised strike points, we use the Corsica code to investigate the range of possible H- and L-mode equilibria, with emphasis on the maximum plasma current, achievable shapes, etc. With raised strike points the maximum achievable plasma current is close to 14 MA. The operating space (?p - li) for raised strike points has been studied. The size of the ?p - li operating space shrinks (compared to using standard strike-point positions) at 14 MA. For 12 MA, however, the operating space is not affected when using raised strike points. For equilibria with elevated strike points (at roughly the CFC/W transitions, following the 2007 ITER Design Review) the vertical-instability growth-rates at high plasma current (14 MA) are somewhat high but are within the 20 s-1 which studies indicate are controllable in ITER. At lower currents (12 MA) in H-mode, the vertical-instability growth rates stay below 10.0 s-1 for most of ?p - li space. At 12 MA in H-mode, multiple equilibria which meet our constraints have been found in overlapping regions of the ?p - li operating space.

  4. Inertial Pointing and Positioning System

    NASA Technical Reports Server (NTRS)

    Yee, Robert (Inventor); Robbins, Fred (Inventor)

    1998-01-01

    An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for-monitoring the terrestrial position and instrument attitude. and for pointing the instrument at designated celestial targets or ground based landmarks. As a result. the pointing instrument and die INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically. the computer calculates the desired instrument angles (Phi, Theta. Psi). which are then compared to the Euler angles measured by the instrument- mounted INS. and forms the pointing command error angles as a result of the compared difference.

  5. Measured environments within 20 meters of the strike points of triggered lightning

    SciTech Connect

    Fisher, R.J.; Schnetzer, G.H.; Morris, M.E.

    1995-08-01

    Vertical electric fields, azimuthal magnetic fields, and earth voltages developed over 0.5-m radial step distances have been measured at 10 and 20 m from the ground attachment point of triggered lightning. The magnetic fields are found to follow Ampere`s law closely. The relationship between maximum vertical electric field change due to a descending dart leader and the peak of its associated return-stroke current is linear. Recorded earth step voltages have the same waveforms as the incident return-stroke currents, and, for distances between 10 and 20 m from the strike point, their amplitudes exhibit a 1/r dependence. Statistics are given for observed radial filamentary arcing from the ground attachment point.

  6. Modification of H-mode threshold power via the variation of outer strike point location

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Hughes, J. W.; Churchill, R. M.; Lipschultz, B.; Labombard, B.; Lau, C.; Marmar, E. S.; Alcator C-Mod Team

    2011-10-01

    In a recent Alcator C-Mod experiment performed in BT = 5.4T, Ip=0.9MA, =1.3-1.6x1020m-3, lower single null plasmas, the required power for H-mode access (Pth) was found to be greatly reduced as the outer strike point was lowered along the vertical plate and onto the horizontal floor of the divertor. The reduction can be as much as a factor of 3. The Pth is found to primarily correlate with the poloidal distance between X-point and the outer strike point, or outer leg length (OLL), such that the magnitudes of Pth generally decrease with increased OLL. Despite the large variation ofPth, the electron temperature (Te) and density (ne) profiles inside the separatrix are seen to be not dramatically different. The roles of neutrals, ion temperature and rotation in the plasma edge and SOL, and SOL ne profiles will be assessed in an attempt to reveal the reason for the experimental observations. Supported by US DoE Award DE-FC02-99-ER54512.

  7. Strike point splitting induced by the application of magnetic perturbations on MAST

    NASA Astrophysics Data System (ADS)

    Cahyna, P.; Peterka, M.; Kirk, A.; Thornton, A.; Harrison, J.; Muir, D.; Panek, R.

    2013-07-01

    Divertor strike point splitting induced by resonant magnetic perturbations (RMPs) has been observed on MAST for a variety of RMP configurations in a plasma scenario with Ip = 750 kA where those configurations all have similar resonant components. Complementary measurements have been obtained with divertor Langmuir probes and an infrared camera. Clear splitting consistently appears in this scenario only in the even configuration of the perturbation coils, similarly to the density pump-out. These results present a challenge for models of plasma response to RMPs.

  8. Gross and net erosion of tungsten in the outer strike-point region of ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Hakola, A.; Airila, M. I.; Karhunen, J.; Groth, M.; Herrmann, A.; Krieger, K.; Kurki-Suonio, T.; Meisl, G.; Oberkofler, M.; Neu, R.; Potzel, S.; Rohde, V.; pre=", ASDEX Upgrade Team

    2016-02-01

    We have investigated net and gross erosion of W in the outer strike-point (OSP) region of ASDEX Upgrade with the help of marker probes during low-density/high-temperature L-mode discharges. Post mortem analyses indicate net-erosion rates of 0.04–0.13 nm s‑1, with the highest rates measured close to the OSP. Re-deposition was some 30–40% of gross erosion, which is lower than what has earlier been obtained spectroscopically (∼50–60%), possibly due to the special plasma conditions of our experiment and intense flux of W atoms originating from the main chamber. Gross erosion was also estimated by passive emission spectroscopy, and around the OSP the results matched with post mortem data. However, the spectroscopic erosion profile in the poloidal direction was much steeper than the post mortem one. Preliminary ERO simulations have predicted net erosion of the same order of magnitude as experimental results but reproducing the poloidal erosion/re-deposition profiles requires further work.

  9. Point Positioning Service for Natural Hazard Monitoring

    NASA Astrophysics Data System (ADS)

    Bar-Sever, Y. E.

    2014-12-01

    In an effort to improve natural hazard monitoring, JPL has invested in updating and enlarging its global real-time GNSS tracking network, and has launched a unique service - real-time precise positioning for natural hazard monitoring, entitled GREAT Alert (GNSS Real-Time Earthquake and Tsunami Alert). GREAT Alert leverages the full technological and operational capability of the JPL's Global Differential GPS System [www.gdgps.net] to offer owners of real-time dual-frequency GNSS receivers: Sub-5 cm (3D RMS) real-time, absolute positioning in ITRF08, regardless of location Under 5 seconds turnaround time Full covariance information Estimates of ancillary parameters (such as troposphere) optionally provided This service enables GNSS networks operators to instantly have access to the most accurate and reliable real-time positioning solutions for their sites, and also to the hundreds of participating sites globally, assuring inter-consistency and uniformity across all solutions. Local authorities with limited technical and financial resources can now access to the best technology, and share environmental data to the benefit of the entire pacific region. We will describe the specialized precise point positioning techniques employed by the GREAT Alert service optimized for natural hazard monitoring, and in particular Earthquake monitoring. We address three fundamental aspects of these applications: 1) small and infrequent motion, 2) the availability of data at a central location, and 3) the need for refined solutions at several time scales

  10. Precise Point Positioning with Partial Ambiguity Fixing.

    PubMed

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  11. Precise Point Positioning with Partial Ambiguity Fixing

    PubMed Central

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  12. Robot positioning based on point-to-point motion capability

    SciTech Connect

    Park, Y. S.; Cho, H. S.; Koh, K. C.

    2000-03-20

    This paper presents an optimal search method for determining the base location of a robot manipulator so that the robot can have a designated point-to-point (PTP) motion capabilities. Based on the topological characterization of the manipulator workspace and the definitions of various p-connectivity, a computational method is developed for enumerating various PTP motion capabilities into quantitative cost functions. Then an unconstrained search by minimizing the cost function yields the task feasible location of the robot base. This methodology is useful for placement of mobile manipulators and robotic workcell layout design.

  13. Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET

    NASA Astrophysics Data System (ADS)

    Harting, D. M.; Liang, Y.; Jachmich, S.; Koslowski, R.; Arnoux, G.; Devaux, S.; Eich, T.; Nardon, E.; Reiter, D.; Thomsen, H.; EFDA contributors, JET

    2012-05-01

    At JET the error field correction coils can be used to generate an n = 1 or n = 2 magnetic perturbation field (Liang et al 2007 Plasma Phys. Control. Fusion 49 B581). Various experiments at JET have already been carried out to investigate the mitigation of ELMs by resonant magnetic perturbations (RMPs) (Liang et al 2010 Nucl. Fusion 50 025013, Liang et al 2011 Nucl. Fusion 51 073001). However, the typical formation of a secondary strike point (strike point splitting) by RMPs observed in other machines (Jakubowski et al 2010 Contrib. Plasma Phys. 50 701-7, Jakubowski et al 2004 Nucl. Fusion 44 S1-11, Nardon et al 2011 J. Nucl. Mater. 415 S914-7, Eich et al 2003 Phys. Rev. Lett. 91 195003, Evans et al 2007 J. Nucl. Mater. 363-365 570-4, Evans et al 2005 J. Phys.: Conf. Ser. 7 174-90, Watkins et al 2009 J. Nucl. Mater. 390-391 839-42) has never been observed at JET before. In this work we will present discharges where for the first time a strike point splitting by RMPs at JET has been observed. We will show that in these particular cases the strike point splitting matches the vacuum edge magnetic field topology. This is done by comparing heat and particle flux profiles on the outer divertor plate with the magnetic footprint pattern obtained by field line tracing. Further the evolution of the strike point splitting during the ramp up phase of the perturbation field and during a q95-scan is investigated, and it will be shown that the spontaneous appearance of the strike point splitting is only related to some geometrical effects of the toroidal asymmetric magnetic topology.

  14. Physician strikes.

    PubMed

    Thompson, Stephen L; Salmon, J Warren

    2014-11-01

    Throughout medical history, physicians have rarely formed unions and/or carried out strikes. In a profession faced with the turmoil of health reform and increasing pressure to change their practices and lifestyles, will physicians resort to unionization for collective bargaining, and will a strike weapon be used to fight back against the array of corporate and government powers involved in the transformation of the American health-care system? This article examines the question of whether there could be such a thing as an ethical physician strike. Although physicians have not historically used collective bargaining or the strike weapon, the rapidly changing practice environment in the United States might push physicians and other health-care professionals toward unionization. This article considers the ethical questions that would arise if physicians started taking advantage of labor laws, and it lays out criteria for an ethical strike. PMID:25367473

  15. Lightning Often Strikes Twice

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Contrary to popular misconception, lightning often strikes the same place twice. Certain conditions are just ripe for a bolt of electricity to come zapping down; and a lightning strike is powerful enough to do a lot of damage wherever it hits. NASA created the Accurate Location of Lightning Strikes technology to determine the ground strike point of lightning and prevent electrical damage in the immediate vicinity of the Space Shuttle launch pads at Kennedy Space Center. The area surrounding the launch pads is enmeshed in a network of electrical wires and components, and electronic equipment is highly susceptible to lightning strike damage. The accurate knowledge of the striking point is important so that crews can determine which equipment or system needs to be retested following a strike. Accurate to within a few yards, this technology can locate a lightning strike in the perimeter of the launch pad. As an added bonus, the engineers, then knowing where the lightning struck, can adjust the variables that may be attracting the lightning, to create a zone that will be less susceptible to future strikes.

  16. Radial arm strike rail

    DOEpatents

    McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO)

    1991-01-01

    The radial arm strike rail assembly is a system for measurement of bearings, directions, and stereophotography for geologic mapping, particularly where magnetic compasses are not appropriate. The radial arm, pivoting around a shaft axis, provides a reference direction determination for geologic mapping and bearing or direction determination. The centerable and levelable pedestal provide a base for the radial arm strike rail and the telescoping camera pedestal. The telescoping feature of the radial arm strike rail allows positioning the end of the rail for strike direction or bearing measurement with a goniometer.

  17. Error analysis in stereo determination of 3-d point positions.

    PubMed

    Blostein, S D; Huang, T S

    1987-06-01

    The relationship between the geometry of a stereo camera setup and the accuracy in obtaining three-dimensional position information is of great practical importance in many imaging applications. Assuming a point in a scene has been correctly identified in each image, its three-dimensional position can be recovered via a simple geometrical method known as triangulation. The probability that position estimates from triangulation are within some specified error tolerance is derived. An ideal pinhole camera model is used and the error is modeled as known spatial image plane quantization. A point's measured position maps to a small volume in 3-D determined by the finite resolution of the stereo setup. With the assumption that the point's actual position is uniformly distributed inside this volume, closed form expressions for the probability distribution of error in position along each coordinate direction (horizontal, vertical, and range) are derived. Following this, the probability that range error dominates over errors in the point's horizontal or vertical position is determined. It is hoped that the results presented will have an impact upon both sensor design and error modeling of position measuring systems for computer vision and related applications. PMID:21869437

  18. Position three in vasopressin antagonist tolerates conformationally restricted and aromatic amino acid substitutions: a striking contrast with vasopressin agonists.

    PubMed

    Manning, M; Cheng, L L; Stoev, S; Klis, W; Nawrocka, E; Olma, A; Sawyer, W H; Wo, N C; Chan, W Y

    1997-01-01

    We report the solid-phase synthesis and some pharmacological properties of 12 position three modified analogues (peptides 1-12) of the potent non-selective antagonist of the antidiuretic (V2-receptor), vasopressor (V1a-receptor) responses to arginine vasopressin (AVP) and of the uterine contracting (OT-receptor) responses to oxytocin (OT), [1(-beta mercapto-beta,beta-pentamethylenepropionic acid)-2-O-ethyl-D-tyrosine 4-valine] arginine vasopressin [d(CH2)5D-Tyr(Et)2VAVP] (A) and two analogues of (B) (peptides 13,14), the 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid3 (Tic3) analogue of (A). Peptides 1-12 have the following substituents at position three in (A): (1) Pro; (2) Oic; (3) Atc; (4) D-Atc; (6) D-Phe; (7) Ile; (8) Leu; (9) Tyr; (10) Trp; (11) Hphe; (12) [HO]Tic; Peptide (13) is the Tyr-NH2(9) analogue of (B): Peptide (14) is the D-Cys(6) analogue of (B). All 14 new peptides were evaluated for agonistic and antagonistic activities in in vivo V2 and V1a assays and in vitro (no Mg2+)n oxytocic assays. With the exception of the D-Phe3 peptide (No. 6), which exhibits very weak V2 agonism (approximately 0.0017 U/mg), none of the remaining 13 peptides exhibit any agonistic activities in these assays. In striking contrast to their deleterious effects on agonistic activities in AVP, the Pro3, Oic3, Tyr3 and Hphe3 substitutions in (A) are very well tolerated, leading to excellent retention of V2, V1a and OT antagonistic potencies. All are more potent as V2 antagonists than the Ile3 and Leu3 analogues of (A). The Tyr-NH2(9) and D-Cys(6) substitutions in (B) are also well tolerated. The anti-V2 pA2 values of peptides 1-5 and 7-14 are as follows (1) 7.77 +/- 0.03; (2) 7.41 +/- 0.05; (3) 6.86 +/- 0.02; (4) 5.66 +/- 0.09; (5) approximately 5.2; (7) 7.25 +/- 0.08; (8) 6.82 +/- 0.06; (9) 7.58 +/- 0.05; (10) 7.61 +/- 0.08; (11) 7.59 +/- 0.07; (12) 7.20 +/- 0.05; (13) 7.57 +/- 0.1; (14) 7.52 +/- 0.06. All analogues antagonize the vasopressor responses to AVP, with anti-V1a pA2 values ranging from 5.62 to 7.64, and the in vitro responses to OT, with anti-OT pA2 values ranging from 5.79 to 7.94. With an anti-V2 potency of 7.77 +/- 0.03, the Pro3 analogue of (A) is surprisingly equipotent with (A), (anti-V2 pA2 = 7.81 +/- 0.07). These findings clearly indicate that position three in AVP V2/V1a antagonists, in contrast to position three in AVP agonists, is much more amenable to structural modification than had heretofore been anticipated. Furthermore, the surprising retention of V2 antagonism exhibited by the Pro3, Oic3, Tyr3, Trp3 and Hphe3 analogues of (A), together with the excellent retention of V2 antagonism by the Tyr-NH2(9) and D-Cys6 analogues of (B) are promising new leads to the design of potent and possibly orally active V2 antagonists for use as pharmacological tools and/or as radioiodinatable ligands and for development as potential therapeutic agents for the treatment of the hyponatremia caused by the syndrome of the inappropriate secretion of the antidiuretic hormone (SIADH). PMID:9230469

  19. Striking Clepsydras

    NASA Astrophysics Data System (ADS)

    Nam, Moon-Hyon

    The term "Striking Clepsydra" is a shortened translation of the Korean name Jagyeongnu (???, tzu-chi lou in Chinese, literally "automatic-striking water-clock"). It was given to the two monumental time-keeping installations built by chief court engineer Yeong-sil Jang in AD 1432-38 under King Sejong (r. AD 1418-50) of the Joseon dynasty (1392-1910) in Seoul. These were housed separately in the Gyeongbok palace complex as major installations of the Royal Observatory Ganuidae equipped during 1432-38. One was the Striking Palace Clepsydra Borugangnu that was employed as the standard time-keeper from 1434, and the other was the Striking Heavenly Clepsydra Heumgyeonggangnu that was put into use not only as the symbol of Neo-Confucian ideology from 1438, but also as a demonstrational orrery and time-keeper. These were restored several times through the dynasty after loss by fires and warfare, and clepsydra-making technologies were succeeded by the development of armillary clocks in 1669. The National Palace Museum of Korea recreated the 1434 Striking Palace Clepsydra of King Sejong, and the replica was installed for permanent exhibition from November 2007.

  20. Strikingly rapid neural basis of motion-induced position shifts revealed by high temporal-resolution EEG pattern classification.

    PubMed

    Hogendoorn, Hinze; Verstraten, Frans A J; Cavanagh, Patrick

    2015-08-01

    Several visual illusions demonstrate that the neural processing of visual position can be affected by visual motion. Well-known examples are the flash-lag, flash-drag, and flash-jump effect. However, where and when in the visual processing hierarchy such interactions take place is unclear. Here, we used a variant of the flash-grab illusion (Vision Research 91 (2013), pp. 8-20) to shift the perceived positions of flashed stimuli, and applied multivariate pattern classification to individual 64-channel EEG trials to dissociate neural signals corresponding to veridical versus perceived position with high temporal resolution. We show illusory effects of motion on perceived position in three separate analyses: (1) A classifier can distinguish different perceived positions of a flashed object, even when the veridical positions are identical. (2) When the perceived positions of two objects presented in different locations become more similar, the classifier performs less well than when they become more different, even if the veridical positions remain unchanged. (3) Finally, a classifier can discriminate the perceived position of an object even when trained on objects presented in physically different positions. These effects are evident as early as 81ms post-stimulus, concurrent with the very first EEG signals indicating that any stimulus is present at all. This finding shows that the illusion must begin at an early level, probably as part of a predominantly feed-forward mechanism, leaving the influence of any recurrent processes to later stages in the development of the effect. PMID:26021721

  1. Tobacco point of sale advertising increases positive brand user imagery

    PubMed Central

    Donovan, R; Jancey, J; Jones, S

    2002-01-01

    Objectives: To determine the potential impact of point of sale advertising on adolescents so as to inform changes to the Tobacco Control Act. Design: Participants were randomly assigned to one of two conditions. In the control condition, students were exposed to a photograph of a packet of cigarettes; in the intervention condition, students were exposed to an ad for cigarettes, typical of point of sale advertising posters. All students then rated the brand user on a set of 12 bipolar adjectives. Two brands were used in the study: Benson & Hedges, and Marlboro. Subjects: One hundred year (grade) 6 and 7 students (age range 1012 years), from four Western Australian metropolitan primary schools, participated in the study. Results: In a majority of the brand user descriptions, the cigarette advertisements increased brand user imagery in a positive way, especially for Benson & Hedges. For example, participants viewing the Benson & Hedges advertisement, as distinct from those viewing the Benson & Hedges pack only, were more likely to describe the Benson & Hedges user as relaxed, interesting, cool, rich, adventurous, and classy. Relative to the Marlboro pack only, the Marlboro ad increased positive perceptions of the Marlboro user on adventurous, interesting, and relaxed. Conclusions: The results presented here support restrictions being placed on advertising at point of sale, since such ads have the potential to increase positive brand user imagery directly in the situation where a product purchase can take place, and hence the potential to increase the likelihood of impulse purchasing. PMID:12198267

  2. Code Single Point Positioning Using Nominal GNSS Constellations (Future Perception)

    NASA Astrophysics Data System (ADS)

    Farah, A. M. A.

    Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation, namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning from different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, GLONASS and Galileo) using different combinations. This study presents results of code single point positioning for five stations using the three constellations and different combinations.

  3. Precise Point Positioning Based on BDS and GPS Observations

    NASA Astrophysics Data System (ADS)

    Gao, ZhouZheng; Zhang, Hongping; Shen, Wenbin

    2014-05-01

    BeiDou Navigation Satellite System (BDS) has obtained the ability applying initial navigation and precise point services for the Asian-Pacific regions at the end of 2012 with the constellation of 5 Geostationary Earth Orbit (GEO), 5 Inclined Geosynchronous Orbit (IGSO) and 4 Medium Earth Orbit (MEO). Till 2020, it will consist with 5 GEO, 3 IGSO and 27 MEO, and apply global navigation service similar to GPS and GLONASS. As we known, GPS precise point positioning (PPP) is a powerful tool for crustal deformation monitoring, GPS meteorology, orbit determination of low earth orbit satellites, high accuracy kinematic positioning et al. However, it accuracy and convergence time are influenced by the quality of pseudo-range observations and the observing geometry between user and Global navigation satellites system (GNSS) satellites. Usually, it takes more than 30 minutes even hours to obtain centimeter level position accuracy for PPP while using GPS dual-frequency observations only. In recent years, many researches have been done to solve this problem. One of the approaches is smooth pseudo-range by carrier-phase observations to improve pseudo-range accuracy. By which can improve PPP initial position accuracy and shorten PPP convergence time. Another sachems is to change position dilution of precision (PDOP) with multi-GNSS observations. Now, BDS has the ability to service whole Asian-Pacific regions, which make it possible to use GPS and BDS for precise positioning. In addition, according to researches on GNSS PDOP distribution, BDS can improve PDOP obviously. Therefore, it necessary to do some researches on PPP performance using both GPS observations and BDS observations, especially in Asian-Pacific regions currently. In this paper, we focus on the influences of BDS to GPS PPP mainly in three terms including BDS PPP accuracy, PDOP improvement and convergence time of PPP based on GPS and BDS observations. Here, the GPS and BDS two-constellation data are collected from BeiDou experimental tracking stations (BETS) built by Wuhan University. And BDS precise orbit and precise clock products are applied by GNSS center, Wuhan University. After an introduction about GPS+BDS PPP mathematical and the error correction modes, we analyze the influence of BDS to GPS PPP carefully with calculating results. The statistics results show that BDS PPP can reach centimeter level and BDS can improve PDOP obviously. Moreover, the convergence time and position stability of GPS+BDS PPP is better than that of GPS PPP.

  4. Local troposphere augmentation for real-time precise point positioning

    NASA Astrophysics Data System (ADS)

    Shi, Junbo; Xu, Chaoqian; Guo, Jiming; Gao, Yang

    2014-12-01

    The IGS real-time service (RTS) enables real-time precise point positioning (PPP) at a global scale. A long convergence time however is still a challenging factor. In order to reduce the convergence time, external troposphere corrections could be introduced to remove the troposphere effects on the coordinate solution. This paper proposes the use of a local troposphere model to augment real-time PPP. First, undifferenced observations from a network of multiple stations are processed to estimate the station-based troposphere zenith wet delay (ZWD). A set of local troposphere fitting coefficients are then derived using a proposed optimal fitting model. Finally, the determined troposphere fitting coefficients are broadcast to users to reduce the convergence time in the user solution. A continuous operating reference station (CORS) network is utilized to assess the performance of the proposed approach under quiet and active troposphere conditions. The numerical results show that the overall fitting precisions of the local troposphere model can reach 1.42 and 1.05 cm under the two troposphere conditions. The convergence time of the positioning solutions, especially the height solution, can be greatly reduced using the local troposphere model. The horizontal accuracy of 9.2 cm and the vertical accuracy of 10.1 cm are obtainable under the quiet troposphere condition after 20 min of initialization time, compared to the 14.7 cm horizontal and 21.5 cm vertical accuracies in the conventional troposphere estimation approach. Moreover, the horizontal accuracies of 13.0 cm and the vertical accuracies of 12.4 cm have also been obtained after 20 min under the active troposphere condition.

  5. GLONASS ionosphere-free ambiguity resolution for precise point positioning

    NASA Astrophysics Data System (ADS)

    Banville, Simon

    2016-02-01

    Current GLONASS satellites transmit signals based on the frequency division multiple access (FDMA) technology. Due to equipment delays occurring within GNSS receivers, GLONASS carrier phase and code observations are contaminated by inter-frequency biases. As a consequence, GLONASS ambiguity parameters in long-baseline processing are typically estimated as float values. In this paper, a strategy is investigated which benefits from the frequency spacing of GLONASS frequencies on the L1 and L2 bands, allowing for an ionosphere-free ambiguity with a wavelength of approximately 5 cm to be defined; therefore, avoiding the problematic wide-lane ambiguity resolution. Based on 12 independent baselines with a mean inter-station distance of about 850 km over a 1-week period, it is demonstrated that close to 95 % of the estimated double-differenced ionosphere-free ambiguities are within 0.15 cycles of an integer, thereby suggesting that long-baseline ambiguity resolution can be achieved for GLONASS. Applying between-station ambiguity constraints in precise point positioning (PPP) solutions was found to improve longitudinal repeatability in static mode by more than 20 % for sessions between 2 and 6 h in duration. In kinematic mode, only limited improvements were made to the initial convergence period since the short wavelength of GLONASS ionosphere-free ambiguities requires the solution to be nearly converged before successful ambiguity resolution can be achieved.

  6. Adaptive robust Kalman filtering for precise point positioning

    NASA Astrophysics Data System (ADS)

    Guo, Fei; Zhang, Xiaohong

    2014-10-01

    The optimality of precise point postioning (PPP) solution using a Kalman filter is closely connected to the quality of the a priori information about the process noise and the updated mesurement noise, which are sometimes difficult to obtain. Also, the estimation enviroment in the case of dynamic or kinematic applications is not always fixed but is subject to change. To overcome these problems, an adaptive robust Kalman filtering algorithm, the main feature of which introduces an equivalent covariance matrix to resist the unexpected outliers and an adaptive factor to balance the contribution of observational information and predicted information from the system dynamic model, is applied for PPP processing. The basic models of PPP including the observation model, dynamic model and stochastic model are provided first. Then an adaptive robust Kalmam filter is developed for PPP. Compared with the conventional robust estimator, only the observation with largest standardized residual will be operated by the IGG III function in each iteration to avoid reducing the contribution of the normal observations or even filter divergence. Finally, tests carried out in both static and kinematic modes have confirmed that the adaptive robust Kalman filter outperforms the classic Kalman filter by turning either the equivalent variance matrix or the adaptive factor or both of them. This becomes evident when analyzing the positioning errors in flight tests at the turns due to the target maneuvering and unknown process/measurement noises.

  7. Single-frequency precise point positioning: an analytical approach

    NASA Astrophysics Data System (ADS)

    Sterle, Oskar; Stopar, Bojan; Pavlovčič Prešeren, Polona

    2015-08-01

    An analytical approach to single-frequency precise point positioning (PPP) is discussed in this paper. To obtain highest precision results, all biases must be eliminated or modelled to centimetre level. The use of the GRAPHIC ionosphere-free linear combination that is based on single-frequency phase and code observations eliminates the ionosphere bias; however, the rank deficient Gauss-Markov model is obtained. We explicitly determine rank deficiency of a Gauss-Markov model as a number of all ambiguity clusters, each of them defined as a set of all ambiguities overlapping in time. On the basis of S-transformation we prove that the single-frequency PPP represents an unbiased estimator for station coordinates and troposphere parameters, while it presents a biased estimator for ambiguities and receiver-clock error parameters. Additionally we describe the estimable parameters in each ambiguity cluster as the differences between ambiguity parameters and the sum of receiver-clock parameters with one of the ambiguities. We also show that any other particular solution on the basis of S-transformation is obtained only when the common least-squares estimation in single step is applied. The recursive least-squares estimation with parameter pre-elimination only determines the vector of unknowns as possible to transform through S-transformation, whereas the same does not hold for the cofactor matrix of unknowns. For a case study, we present our method on GPS data from 19 permanent stations (14 IGS and 5 EPN) in Europe, for 89 consecutive days in the beginning of 2013. The static case study revealed the precision of daily coordinates as 7.6, 11.7 and 19.6 mm for , and , respectively. The accuracies of the , and components were determined as 6.9, 13.5 and 31.4 mm, respectively, and were calculated using the Helmert transformation of weighted-mean daily single-frequency PPP and IGb08 coordinates. The estimated convergence times were relatively diverse, expanding from 1.75 h (CAGL) to 5.25 h (GRAZ) for the horizontal position with the 10-cm precision threshold, and from 1.00 h (GRAS) to 3.25 h (BZRG) for the height component with a 20-cm precision threshold. The convergence times were shown to be strongly correlated to the remaining unmodelled biases in the GRAPHIC linear combination, primarily with multipath, where the correlation coefficient for the horizontal position was determined as 0.68 and for height as 0.85. The comparison to the model where raw observations are used (, ) and where the ionosphere bias is mitigated with global ionosphere models (GIM) revealed the supremacy of the proposed single-frequency PPP method based on the GRAPHIC linear combination in both the static and the semi-kinematic case study. In the static case study, the proposed single-frequency PPP model was superior both in terms of precision and accuracy. In the semi-kinematic case study, the usage of raw observations with GIM would improve results only when multipath and noise of code observations would prevail over the remaining ionosphere bias, i.e. after applying GIM.

  8. Should junior doctors strike?

    PubMed

    Toynbee, Mark; Al-Diwani, Adam Aj; Clacey, Joe; Broome, Matthew R

    2016-03-01

    An impasse in negotiations between the Department of Health (DoH) and the British Medical Association in November this year led to an overwhelming vote for industrial action (IA) by junior doctors. At the time of writing, a last minute concession by DoH led to a deferment of IA to allow further negotiations mediated by the Advisory, Conciliation and Arbitration Service. However, IA by junior doctors remains a possibility if these negotiations stall again. Would the proposed action be ethically justifiable? Furthermore, is IA by doctors ever ethically defendable? Building on previous work, we explore important ethical considerations for doctors considering IA. The primary moral objection to doctors striking is often claimed to be risk of harm to patients. Other common arguments against IA by doctors include breaching their vocational responsibilities and possible damage to their relationship with patients and the public in general. These positions are in turn countered by claims of a greater long-term good and the legal and moral rights of employees to strike. Absolute restrictions appear to be hard to justify in the modern context, as does an unrestricted right to IA. We review these arguments, find that some common moral objections to doctors striking may be less relevant to the current situation, that a stronger contemporary objection to IA might be from a position of social justice and suggest criteria for ethically permissible doctor IA. PMID:26758366

  9. Integer ambiguity resolution in precise point positioning: method comparison

    NASA Astrophysics Data System (ADS)

    Geng, Jianghui; Meng, Xiaolin; Dodson, Alan H.; Teferle, Felix N.

    2010-09-01

    Integer ambiguity resolution at a single receiver can be implemented by applying improved satellite products where the fractional-cycle biases (FCBs) have been separated from the integer ambiguities in a network solution. One method to achieve these products is to estimate the FCBs by averaging the fractional parts of the float ambiguity estimates, and the other is to estimate the integer-recovery clocks by fixing the undifferenced ambiguities to integers in advance. In this paper, we theoretically prove the equivalence of the ambiguity-fixed position estimates derived from these two methods by assuming that the FCBs are hardware-dependent and only they are assimilated into the clocks and ambiguities. To verify this equivalence, we implement both methods in the Position and Navigation Data Analyst software to process 1 year of GPS data from a global network of about 350 stations. The mean biases between all daily position estimates derived from these two methods are only 0.2, 0.1 and 0.0 mm, whereas the standard deviations of all position differences are only 1.3, 0.8 and 2.0 mm for the East, North and Up components, respectively. Moreover, the differences of the position repeatabilities are below 0.2 mm on average for all three components. The RMS of the position estimates minus those from the International GNSS Service weekly solutions for the former method differs by below 0.1 mm on average for each component from that for the latter method. Therefore, considering the recognized millimeter-level precision of current GPS-derived daily positions, these statistics empirically demonstrate the theoretical equivalence of the ambiguity-fixed position estimates derived from these two methods. In practice, we note that the former method is compatible with current official clock-generation methods, whereas the latter method is not, but can potentially lead to slightly better positioning quality.

  10. Positively coded photoaffinity label for altering isoelectric points of proteins.

    PubMed

    Hashimoto, Makoto; Hatanaka, Yasumaru

    2006-12-01

    Novel diazirinyl photoaffinity ligand, which contains (3-trifluoromethyl) phenyldiazirine and penta(epsilon-Boc-Lys) as a photoreactive code, allows the introduction of a positive cascade to alter the pI value of labeled components, facilitating the isolation of photolabeled biocomponents with isoelectric focusing techniques. PMID:16982189

  11. Three-Point Gear/Lead Screw Positioning

    NASA Technical Reports Server (NTRS)

    Calco, Frank S.

    1993-01-01

    Triple-ganged-lead-screw positioning mechanism drives movable plate toward or away from fixed plate and keeps plates parallel to each other. Designed for use in tuning microwave resonant cavity. Other potential applications include adjustable bed plates and cantilever tail stocks in machine tools, adjustable platforms for optical equipment, and lifting platforms.

  12. Lightning strike experience

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A program implemented to report various lightning-strike incidents was reviewed. Strike incidence data was summarized according to aircraft altitude, flight path, meteorological conditions and atmospheric air temperature. Data was given indicating the incidence of reported lightning strikes to commercial and U.S. Air Force aircraft and an outline of pilot opinion in lightning avoidance was given.

  13. Limit Cycles in a Class of Quartic Kolmogorov Model with Three Positive Equilibrium Points

    NASA Astrophysics Data System (ADS)

    Du, Chaoxiong; Liu, Yirong; Zhang, Qi

    2015-06-01

    Limit cycle bifurcation problem of Kolmogorov model is interesting and significant both in theory and applications. In this paper, we will focus on investigating limit cycles for a class of quartic Kolmogorov model with three positive equilibrium points. Perturbed model can bifurcate three small limit cycles near (1, 2) or (2, 1) under a certain condition and can bifurcate one limit cycle near (1, 1). In addition, we have given some examples of simultaneous Hopf bifurcation and the structure of limit cycles bifurcated from three positive equilibrium points. The limit cycle bifurcation problem for Kolmogorov model with several positive equilibrium points are less seen in published references. Our result is good and interesting.

  14. Constraints on arm position when pointing in three dimensions: Donders' law and the Fick gimbal strategy.

    PubMed

    Hore, J; Watts, S; Vilis, T

    1992-08-01

    1. While making saccades between targets with the head stationary, eye positions are constrained to two of the possible three degrees of freedom. Classically this constraint has been described by Donders' and Listing's laws. The objective was to determine whether these laws also apply for the straight arm when pointing between different targets. Thus we determined whether the arm adopts only one angular position for every pointing direction (Donders' law) and whether these positions can be described by rotations from a reference position about axes that lie in a plane (Listing's law). 2. The angular positions (orientations) of the arm in three-dimensional space were studied as subjects pointed with a straight arm at different targets. Arm position was measured with the search coil technique by means of coils attached to the back of the hand. Pointing was studied over a range of +/- 45 degrees in all directions from a central target located 45 degrees to the right of the straight-ahead position. 3. The positions of the arm in space were described by quaternion vectors, i.e., a particular position was described in terms of the axis and amplitude of a rotation from a reference position to that position. Using this description, it was found that the straight arm adopted a similar orientation (standard deviations ranged from 2.8 to 4.8 degrees) when pointing at a particular target irrespective of which target from which it had moved. 4. The angular position vectors for arm positions associated with relatively small movements (e.g., less than +/- 30 degrees) lay in a flat surface with minimal torsion. At first sight, this surface appeared to be similar to Listing's plane of the eye. However, for positions associated with larger movements (e.g., +/- 45 degrees) it became apparent that, unlike the eye, the surface deviated from one obeying Listing's law, i.e., it was twisted and showed torsion like that produced by rotations around the horizontal and vertical axes of a Fick gimbal. (The characteristic of a Fick gimbal is that the vertical axis is fixed, whereas the horizontal axis moves with the gimbal.) 5. Although there were differences between subjects, all showed a twisted position vector surface. The twist was always in the same direction, and it was always less than that of a Fick gimbal. 6. This position vector surface had a similar shape whether the arm was stationary or was moving between targets, whether subjects pointed with or without vision, and whether the pointing arm had moved between targets or from a bent-elbow position on the lap.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1527564

  15. Existence of triple positive solutions for a third-order three-point boundary value problem

    NASA Astrophysics Data System (ADS)

    Sun, Yongping

    2008-11-01

    In this paper we investigate the existence of triple positive solutions for the nonlinear third-order three-point boundary value problem where are constants. are continuous. First, Green's function for the associated linear boundary value problem is constructed, and then, by using a fixed-point theorem due to Avery and Peterson, we establish results on the existence of triple positive solutions to the boundary value problem.

  16. An Integer Precise Point Positioning technique for sea surface observations using a GPS buoy

    NASA Astrophysics Data System (ADS)

    Fund, F.; Perosanz, F.; Testut, L.; Loyer, S.

    2013-04-01

    GPS data dedicated to sea surface observation are usually processed using differential techniques. Unfortunately, the precision of resulting kinematic positions is baseline-length dependent. So, high precision sea surface observations using differential GPS techniques are limited to coasts, lakes, and rivers. Recent improvements in GPS satellite products (orbits, clocks, and phase biases) make phase ambiguity fixing at the zero difference level achievable and opens up the observation of the sea surface without geographical constraints. This paper recalls the concept of the Integer Precise Point Positioning technique and discusses the precision of GPS buoy positioning. A sequential version of the GINS software has been implemented to achieve single epoch GPS positioning. We used 1 Hz data from a two week GPS campaign conducted in the Kerguelen Islands. A GPS buoy has been moored close to a radar gauge and 90 m away from a permanent GPS station. This infrastructure offers the opportunity to compare both kinematic Integer Precise Point Positioning and classical differential GPS positioning techniques to in situ radar gauge data. We found that Precise Point Positioning results are not significantly biased with respect to radar gauge data and that horizontal time series are consistent with differential processing at the sub-centimetre precision level. Nevertheless, standard deviations of height time series with respect to radar gauge data are typically [4-5] cm. The dominant driver for noise at this level is attributed to errors in tropospheric estimates which propagate into position solutions.

  17. Incorporation of the GPS satellite ephemeris covariance matrix into the precise point positioning

    NASA Astrophysics Data System (ADS)

    Shirazian, Masoud

    2013-09-01

    In GPS positioning, usually the satellite ephemeris are fixed in the observation equations using broadcast or published values. Therefore, to have a realistic covariance matrix for the observations one must incorporate a well-defined covariance matrix of the satellite ephemeris into the observations covariance matrix. Contributions so far have discussed only the variance and covariance of the observations. Precise Point Positioning (PPP) is a technique aimed at processing of measurements from a single (stand-alone) GPS receiver to compute high-accurate position. In this paper, the covariance matrix of the satellite ephemeris and its impact on the position estimates through the PPP are discussed.

  18. GPS-based orbit determination and point positioning under selective availability

    NASA Astrophysics Data System (ADS)

    Bar-Sever, Yoaz E.; Yunck, Thomas P.; Wu, Sien-Chong

    Selective availability (SA) degrades the positioning accuracy for nondifferential users of the GPS Standard Positioning Service (SPS). The often quoted SPS accuracy available under normal conditions is 100 m 2DRMS. In the absence of more specific information, many prospective SPS users adopt the 100 m value in their planning, which exaggerates the error in many cases. SA error is examined for point positioning and dynamic orbit determination for an orbiting user. To minimize SA error, nondifferential users have several options: expand their field of view; observe as many GPS satellites as possible; smooth the error over time; and employ precise GPS ephemerides computed independently, as by NASA and the NGS, rather than the broadcast ephemeris. Simulations show that 3D point position error can be kept to 30 m, and this can be smoothed to 3 m in a few hours.

  19. GPS-based orbit determination and point positioning under selective availability

    NASA Technical Reports Server (NTRS)

    Bar-Sever, Yoaz E.; Yunck, Thomas P.; Wu, Sien-Chong

    1990-01-01

    Selective availability (SA) degrades the positioning accuracy for nondifferential users of the GPS Standard Positioning Service (SPS). The often quoted SPS accuracy available under normal conditions is 100 m 2DRMS. In the absence of more specific information, many prospective SPS users adopt the 100 m value in their planning, which exaggerates the error in many cases. SA error is examined for point positioning and dynamic orbit determination for an orbiting user. To minimize SA error, nondifferential users have several options: expand their field of view; observe as many GPS satellites as possible; smooth the error over time; and employ precise GPS ephemerides computed independently, as by NASA and the NGS, rather than the broadcast ephemeris. Simulations show that 3D point position error can be kept to 30 m, and this can be smoothed to 3 m in a few hours.

  20. Strikingly high false positivity of surveillance FDG-PET/CT scanning among patients with diffuse large cell lymphoma in the rituximab era.

    PubMed

    Avivi, Irit; Zilberlicht, Ariel; Dann, Eldad J; Leiba, Ronit; Faibish, Tal; Rowe, Jacob M; Bar-Shalom, Rachel

    2013-05-01

    Predictive value (PV) of surveillance fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with diffuse large B-cell lymphoma (DLBCL) treated with chemotherapy-rituximab (R) versus chemotherapy only, remains unclear. The aim of the current study was to compare the performance of surveillance PET in DLBCL patients receiving CHOP (cyclophosphamide, hydroxydaunorubicin hydrochloride, vincristine, and prednisone) alone versus CHOP-R. Institutional database was retrospectively searched for adults with newly diagnosed DLBCL, receiving CHOP or CHOP-R, who achieved complete remission and underwent surveillance PETs. Follow-up (FU) PET was considered positive for recurrence in case of an uptake unrelated to physiological or known benign process. Results were confirmed by biopsy, imaging and clinical FU. One hundred nineteen patients, 35 receiving CHOP and 84 CHOP-R, who underwent 422 FU-PETs, were analyzed. At a median PET-FU of 3.4 years, 31 patients relapsed (17 vs. 14, respectively; P = 0.02). PET detected all relapses, with no false-negative studies. Specificity and positive PV (PPV) were significantly lower for patients receiving CHOP-R vs. CHOP (84% vs. 87%, P = 0.023; 23% vs. 74%, P < 0.0001), reflecting a higher false-positive (FP) rate in subjects receiving CHOP-R (77% vs. 26%, P < 0.001). In the latter group, FP-rate remained persistently high up to 3 years post-therapy. Multivariate analysis confirmed rituximab to be the most significant predictor for FP-PET. In conclusion, routine surveillance FDG-PET is not recommended in DLBCL treated with rituximab; strict criteria identifying patients in whom FU-PET is beneficial are required. PMID:23423884

  1. X-point position dependence of edge intrinsic toroidal rotation on the Tokamak Configuration Variablea)

    NASA Astrophysics Data System (ADS)

    Stoltzfus-Dueck, T.; Karpushov, A. N.; Sauter, O.; Duval, B. P.; Labit, B.; Reimerdes, H.; Vijvers, W. A. J.; Camenen, Y.

    2015-05-01

    Recent theoretical work predicts intrinsic toroidal rotation in the tokamak edge to depend strongly on the normalized major radial position of the X-point. With this motivation, we conducted a series of Ohmic L-mode shots on the Tokamak Configuration Variable, moving the X-point from the inboard to the outboard edge of the last closed flux surface in both lower and upper single null configurations. The edge toroidal rotation evolved from strongly co-current for an inboard X-point to either vanishing or counter-current for an outboard X-point, in agreement with the theoretical expectations. The whole rotation profile shifted roughly rigidly with the edge rotation, resulting in variation of the peak core rotation by more than a factor of two. Core rotation reversals had little effect on the edge rotation. Edge rotation was slightly more counter-current for unfavorable than favorable ?B drift discharges.

  2. X-point position dependence of edge intrinsic toroidal rotation on the Tokamak Configuration Variable

    SciTech Connect

    Stoltzfus-Dueck, T.; Karpushov, A. N.; Sauter, O.; Duval, B. P.; Labit, B.; Reimerdes, H.; Vijvers, W. A. J.; Camenen, Y.

    2015-05-15

    Recent theoretical work predicts intrinsic toroidal rotation in the tokamak edge to depend strongly on the normalized major radial position of the X-point. With this motivation, we conducted a series of Ohmic L-mode shots on the Tokamak Configuration Variable, moving the X-point from the inboard to the outboard edge of the last closed flux surface in both lower and upper single null configurations. The edge toroidal rotation evolved from strongly co-current for an inboard X-point to either vanishing or counter-current for an outboard X-point, in agreement with the theoretical expectations. The whole rotation profile shifted roughly rigidly with the edge rotation, resulting in variation of the peak core rotation by more than a factor of two. Core rotation reversals had little effect on the edge rotation. Edge rotation was slightly more counter-current for unfavorable than favorable ?B drift discharges.

  3. Position 4 analogues of [deamino-Cys(1)] arginine vasopressin exhibit striking species differences for human and rat V(2)/V(1b) receptor selectivity.

    PubMed

    Guillon, Gilles; Pena, Ana; Murat, Brigitte; Derick, Sylvain; Trueba, Miguel; Ventura, Maria A; Szeto, Hazel H; Wo, Nga; Stoev, Stoytcho; Cheng, Ling Ling; Manning, Maurice

    2006-03-01

    Arginine vasopressin (AVP) mediates a wide variety of biological actions by acting on three distinct G-protein coupled receptors, termed V(1a) (vascular), V(1b) (pituitary) and V(2) (renal). It also binds to the oxytocin (OT) receptor. As part of a program aimed at the design of selective agonists for the human V(1b) receptor, we recently reported the human V(1b), V(1a), V(2) and OT receptor affinities of the following position 4 substituted analogues of [deamino-Cys(1)] arginine vasopressin (dAVP)-(1) d[Leu(4)]AVP, (2) d[Orn(4)]AVP, (3) d[Lys(4)]AVP, (4) d[Har(4)]AVP, (5) d[Arg(4)]AVP, (6) d[Val(4)]AVP, (7) d[Ala(4)]AVP, (8) d[Abu(4)]AVP, (9) d[Nva(4)]AVP, (10) d[Nle(4)]AVP, (11) d[Ile(4)]AVP, (12) d[Phe(4)]AVP, (13) d[Asn(4)]AVP, (14) d[Thr(4)]AVP: (15) d[Dap(4)]AVP. With the exception of Nos. 7 and 12, all peptides exhibit very high affinities for the human V(1b) receptor. Furthermore, peptides 1-4 exhibit high selectivities for the human V(1b) receptor with respect to the V(1a), V(2) and OT receptors and, with d[Cha(4)]AVP, in functional tests, are the first high affinity selective agonists for the human V(1b) receptor (Cheng LL et al., J. Med. Chem. 47: 2375-2388, 2004). We report here the pharmacological properties of peptides 1-4, 5 (from a resynthesis), 7, 9-13, 15 in rat bioassays (antidiuretic, vasopressor and oxytocic) (in vitro: no Mg(++)) with those previously reported for peptides 5, 6, 8, 14. We also report the rat V(1b), V(1a), V(2) and OT receptor affinities of peptides 1-5 and the rat V(2) receptor affinities for peptides: 7-15.The antidiuretic activities in units/mg of peptides 1-15, are: 1=378; 2=260; 3=35; 4=505; 5=748; 6=1150; 7=841; 8=1020; 9=877; 10=1141; 11=819, 12=110; 13=996; 14=758; 15=1053. Peptides 1-4 exhibit respectively the following rat and human (in brackets) V(2) receptor affinities: 1=3.1 nm (245 nm); 2=3.4 nm (1125 nm); 3=24.6 nm (11,170 nm); 4=0.6 nm (1386 nm). Their rat V(1b) receptor affinities are 1=0.02 nm; 2=0.45 nm; 3=9.8 nm; 4=0.32 nm. Their rat V(1a) receptor affinities are 1=1252 nm; 2=900 nm; 3=1478 nm; 4=32 nm. Their rat oxytocin (OT) receptor affinities are 1=481 nm; 2=997 nm; 3=5042 nm; 4=2996 nm. All four peptides have high affinities and selectivities for the rat V(1b) receptor with respect to the rat V(1a) and OT receptors. However, in contrast to their high selectivity for the human V(1b) receptor with respect to the human V(2) receptor, they are not selective for the V(1b) receptor with respect to the V(2) receptor in the rat. These findings confirm previous observations of profound species differences between the rat and human V(2) receptors. Peptides 1-4 are promising leads to the design of the first high affinity selective agonists for the rat V(1b) receptor. PMID:16130178

  4. Development of Electronics for the ATF2 Interaction Point Region Beam Position Monitor

    SciTech Connect

    Kim, Youngim; Heo, Ae-young; Kim, Eun-San; Boogert, Stewart; Honda, Yosuke; Tauchi, Toshiaki; Terunuma, Nobuhiro; May, Justin; McCormick, Douglas; Smith, Tonee; /SLAC

    2012-08-14

    Nanometer resolution beam position monitors have been developed to measure and control beam position stability at the interaction point region of ATF2. The position of the beam has to be measured to within a few nanometers at the interaction point. In order to achieve this performance, electronics for the low-Q IP-BPM was developed. Every component of the electronics have been simulated and checked on the bench and using the ATF2 beam. We will explain each component and define their working range. Then, we will show the performance of the electronics measured with beam signal. ATF2 is a final focus test beam line for ILC in the framework of the ATF international collaboration. The new beam line was constructed to extend the extraction line at ATF, KEK, Japan. The first goal of ATF2 is the acheiving of a 37 nm vertical beam size at focal point (IP). The second goal is to stabilize the beam at the focal point at a few nanometer level for a long period in order to ensure the high luminosity. To achieve these goals a high resolution IP-BPM is essential. In addition for feedback applications a low-Q system is desirable.

  5. Research on acupuncture points and cortical functional activation position in cats by infrared imaging detection

    NASA Astrophysics Data System (ADS)

    Chen, Shuwang; Sha, Zhanyou; Wang, Shuhai; Wen, Huanming

    2007-12-01

    The research of the brain cognition is mainly to find out the activation position in brain according to the stimulation at present in the world. The research regards the animals as the experimental objects and explores the stimulation response on the cerebral cortex of acupuncture. It provides a new method, which can detect the activation position on the creatural cerebral cortex directly by middle-far infrared imaging. According to the theory of local temperature situation, the difference of cortical temperature maybe associate with the excitement of cortical nerve cells, the metabolism of local tissue and the local hemal circulation. Direct naked detection of temperature variety on cerebral cortex is applied by middle and far infrared imaging technology. So the activation position is ascertained. The effect of stimulation response is superior to other indirect methods. After removing the skulls on the head, full of cerebral cortex of a cat are exposed. By observing the infrared images and measuring the temperatures of the visual cerebral cortex during the process of acupuncturing, the points are used to judge the activation position. The variety in the cortical functional sections is corresponding to the result of the acupuncture points in terms of infrared images and temperatures. According to experimental results, we know that the variety of a cortical functional section is corresponding to a special acupuncture point exactly.

  6. Regional gravity field modeling by the free-positioned point mass method

    NASA Astrophysics Data System (ADS)

    Lin, Miao; Denker, Heiner; Müller, Jürgen

    2013-04-01

    The remove-compute-restore technique can be regarded as a state-of-the-art procedure for regional gravity field modeling, in which the long and short wavelength contributions from a spherical harmonic model and a DTM are first removed from the observations, then gravity field modeling techniques are applied to the residuals, and finally the corresponding long and short wavelength contributions are restored back. In this contribution the emphasis is on the second step, i.e., the compute or modeling step. Besides the classical integral and least-squares collocation (LSC) methods, the estimation based on radial basis functions is another interesting approach for regional gravity field modeling. The point mass method belongs to the latter category, where the basis functions with respect to the disturbing potential are the reciprocal distances between the function and observation locations. The choice of the positions and number of the point masses plays a crucial role in this method, and even in other related estimation methods. In order to solve this problem, the concept of the free-positioned point masses proposed by Barthelmes (1986) seems to be a good choice, in which the point masses are searched stepwise with simultaneous determination of the corresponding point mass positions and magnitudes within an iterative nonlinear least-squares approach. In this study, four different nonlinear iterative algorithms (Levenberg-Marquardt, L-BFGS, L-BFGS-B, and NLCG) have been implemented for regional gravity field modeling. The applicability and performance of each algorithm is demonstrated by two numerical tests with simulated and real data, respectively. In each test, different aspects (e.g., the use of original or reduced basis functions, the use of 2 or 4 parameters for each point mass), affecting the quality of the solutions, are discussed. Furthermore, the results are compared to the classical LSC solutions.

  7. Analytical expressions for position error in triangulation solution of point in space for several station configurations

    NASA Technical Reports Server (NTRS)

    Long, S. A. T.

    1974-01-01

    Analytical expressions are derived to first order for the rms position error in the triangulation solution of a point object in space for several ideal observation-station configurations. These expressions provide insights into the nature of the dependence of the rms position error on certain of the experimental parameters involved. The station geometries examined are: (1) the configuration of two arbitrarily located stations; (2) the symmetrical circular configuration of two or more stations with equal elevation angles; and (3) the circular configuration of more than two stations with equal elevation angles, when one of the stations is permitted to drift around the circle from its position of symmetry. The expressions for the rms position error are expressed as functions of the rms line-of-sight errors, the total number of stations of interest, and the elevation angles.

  8. The massless Thirring model: Positivity of Klaiber's n-point functions

    NASA Astrophysics Data System (ADS)

    Carey, A. L.; Ruijsenaars, S. N. M.; Wright, J. D.

    1985-09-01

    We present a simple solution to the problem of proving positivity of Klaiber's n-point functions for the massless Thirring model. The corresponding fields are obtained as strong limits of explicitly given approximate fields, obviating reconstruction. By invoking recent results on the boson-fermion correspondence it is shown how the model can be formulated on the charged fermion Fock space. It is pointed out that the question of cyclicity of the vacuum is open, and that an affirmative answer is necessary to confirm the superselection sector picture of the model.

  9. X-Point-Position-Dependent Intrinsic Toroidal Rotation in the Edge of the TCV Tokamak.

    PubMed

    Stoltzfus-Dueck, T; Karpushov, A N; Sauter, O; Duval, B P; Labit, B; Reimerdes, H; Vijvers, W A J; Camenen, Y

    2015-06-19

    Edge intrinsic rotation was investigated in Ohmic L-mode discharges on the Tokamak Configuration Variable, scanning the major radial position of the X point, R(X). Edge rotation decreased linearly with increasing R(X), vanishing or becoming countercurrent for an outboard X point, in agreement with theoretical expectations. The core rotation profile shifted fairly rigidly with the edge rotation, changing the central rotation speed by more than a factor of two. Core rotation reversals had little effect on the edge rotation velocity. Edge rotation was modestly more countercurrent in unfavorable than favorable ?B shots. PMID:26196980

  10. Stochastic Modeling Considering Ionospheric Scintillation Effects on GNSS Relative and Point Positioning

    NASA Astrophysics Data System (ADS)

    Silva, H. A.; Camargo, P. D.; Monico, J. F.; Aquino, M.; Marques, H. A.; de Franceschi, G.

    2008-12-01

    Nowadays, Global Navigation Satellite Systems (GNSS), especially the Global Positioning System (GPS), represent one of the most used techniques for geodetic positioning. The functional models related with the GNSS observables are better understood than the stochastic models, considering that the development of the latter is more complex. Usually, the stochastic models are used in a simplified form, as the standard models, which assume that all the GNSS observables are statistically independent and have the same variance. However, the stochastic models may be investigated in more detail, considering for example, the effects of ionospheric scintillation. The high latitudes regions experiment strong influence of the ionospheric effects, in particular ionospheric scintillation. Considering the availability of specially designed GNSS receivers that provide ionospheric scintillation parameters, these effects can be mitigated through improved stochastic models. This paper presents the methodology and results from GPS relative and point positioning considering ionospheric scintillation in the stochastic modeling. Two programs have been developed to obtain the results from relative and point positioning: "GPSeq" (currently under development at the FCT/UNESP Sao Paulo State University - Brazil) and "pp_sc" (developed in a collaborative project between FCT/UNESP and Nottingham University - UK). The point positioning approach can be realized considering an epoch by epoch solution and the relative positioning using a Kalman Filter and the LAMBDA method to solve the Double Differences ambiguities. Both programs have the option to estimate the ionospheric residuals as one stochastic process using the white noise or random walk correlation models. In both cases it is also possible to use the L1/L2 ion-free linear combination. The stochastic modeling considering ionospheric scintillation has been implemented based in the models of Conker et al. (2003), following the approach described in Aquino et al. (2008). Data from a network of GPS Ionospheric Scintillation and TEC Monitor (GISTM) receivers set up in Northern Europe was used in the experiments as can be seen in De Franceschi et al. (2006) and Romano et al. (2008). The point positioning results have shown improvements of the order of 5 to 20 percent when considering the proposed stochastic modeling. In relative positioning, improvements of the order of 20 percent have been achieved. These and further results will be discussed in this paper.

  11. Hunger strike for science

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    Lamenting the degenerating working conditions for scientists in Russia, geophysicist Vladimir Strakhov and physicist Igor Naumenko-Bondarenko of the United Institute of Physics of the Earth (UIPE) at the Russian Academy of Sciences (RAS) have begun a hunger strike. Strakhov is General Director of UIPE, and Naumenko-Bondarenko is chairman of the Trade Union Committee of UIPE.In a press statement released on September 30 in Moscow, the geophysicists stated that they are striking to protest the policy of the Government of the Russian Federation with regard to Russian science in general and to the Russian Academy of Sciences in particular. They blame governmental neglect and, specifically, the non-payment of funds that were in the 1996 budget for the virtual collapse of Russian science.

  12. Tunable band gap near the Dirac point in nonlinear negative-zero-positive index metamaterial waveguide

    SciTech Connect

    Shen Ming; Ruan Linxu; Shi Jielong; Wang Qi; Wang Xinglin

    2011-04-15

    We make theoretical investigations of the nonlinear guided modes near the Dirac point (DP) in nonlinear negative-zero-positive index metamaterial (NZPIM) waveguide. When the nonlinearity is self-focusing, an asymmetric forbidden band exists near the DP that can be modulated by the strength of the nonlinearity. However, the self-defocusing nonlinearity can completely eliminate the asymmetric band gap. We also study the nonlinear surface waves in such nonlinear NZPIM waveguide. These results may predict analogous phenomena in nonlinear graphene.

  13. Position Estimation of Access Points in 802.11 Wireless Networks

    SciTech Connect

    Kent, C A; Dowla, F U; Atwal, P K; Lennon, W J

    2003-12-05

    We developed a technique to locate wireless network nodes using multiple time-of-flight range measurements in a position estimate. When used with communication methods that allow propagation through walls, such as Ultra-Wideband and 802.11, we can locate network nodes in buildings and in caves where GPS is unavailable. This paper details the implementation on an 802.11a network where we demonstrated the ability to locate a network access point to within 20 feet.

  14. Bowl breakout: Escaping the positive region when searching for saddle points

    SciTech Connect

    Pedersen, Andreas; Luiser, Mathieu

    2014-07-14

    We present a scheme improving the minimum-mode following method for finding first order saddle points by confining the displacements of atoms to the subset of those subject to the largest force. By doing so it is ensured that the displacement remains of a local character within regions where all eigenvalues of the Hessian matrix are positive. However, as soon as a region is entered where an eigenvalue turns negative all atoms are released to maintain the ability of determining concerted moves. Applying the proposed scheme reduces the required number of force calls for the determination of connected saddle points by a factor two or more compared to a free search. Furthermore, a wider distribution of the relevant low barrier saddle points is obtained. Finally, the dependency on the initial distortion and the applied maximal step size is reduced making minimum-mode guided searches both more robust and applicable.

  15. Estimated results analysis and application of the precise point positioning based high-accuracy ionosphere delay

    NASA Astrophysics Data System (ADS)

    Wang, Shi-tai; Peng, Jun-huan

    2015-12-01

    The characterization of ionosphere delay estimated with precise point positioning is analyzed in this paper. The estimation, interpolation and application of the ionosphere delay are studied based on the processing of 24-h data from 5 observation stations. The results show that the estimated ionosphere delay is affected by the hardware delay bias from receiver so that there is a difference between the estimated and interpolated results. The results also show that the RMSs (root mean squares) are bigger, while the STDs (standard deviations) are better than 0.11 m. When the satellite difference is used, the hardware delay bias can be canceled. The interpolated satellite-differenced ionosphere delay is better than 0.11 m. Although there is a difference between the between the estimated and interpolated ionosphere delay results it cannot affect its application in single-frequency positioning and the positioning accuracy can reach cm level.

  16. Precise Point Positioning for the Efficient and Robust Analysis of GPS Data From Large Networks

    NASA Technical Reports Server (NTRS)

    Zumberge, J. F.; Heflin, M. B.; Jefferson, D. C.; Watkins, M. M.; Webb, F. H.

    1997-01-01

    Networks of dozens to hundreds of permanently operating precision Global Positioning System (GPS) receivers are emerging at spatial scales that range from 10(exp 0) to 10(exp 3) km. To keep the computational burden associated with the analysis of such data economically feasible, one approach is to first determine precise GPS satellite positions and clock corrections from a globally distributed network of GPS receivers. Then, data from the local network are analyzed by estimating receiver specific parameters with receiver-specific data; satellite parameters are held fixed at their values determined in the global solution. This "precise point positioning" allows analysis of data from hundreds to thousands of sites every day with 40 Mflop computers, with results comparable in quality to the simultaneous analysis of all data. The reference frames for the global and network solutions can be free of distortion imposed by erroneous fiducial constraints on any sites.

  17. Precise Point Positioning for the Efficient and Robust Analysis of GPS Data from Large Networks

    NASA Technical Reports Server (NTRS)

    Zumberge, J. F.; Heflin, M. B.; Jefferson, D. C.; Watkins, M. M.; Webb, F. H.

    1997-01-01

    Networks of dozens to hundreds of permanently operating precision Global Positioning System (GPS) receivers are emerging at spatial scales that range from 10(exp 0) to 10(exp 3) km. To keep the computational burden associated with the analysis of such data economically feasible, one approach is to first determine precise GPS satellite positions and clock corrections from a globally distributed network of GPS receivers. Their, data from the local network are analyzed by estimating receiver- specific parameters with receiver-specific data satellite parameters are held fixed at their values determined in the global solution. This "precise point positioning" allows analysis of data from hundreds to thousands of sites every (lay with 40-Mflop computers, with results comparable in quality to the simultaneous analysis of all data. The reference frames for the global and network solutions can be free of distortion imposed by erroneous fiducial constraints on any sites.

  18. Precise Point Positioning technique for short and long baselines time transfer

    NASA Astrophysics Data System (ADS)

    Lejba, Pawel; Nawrocki, Jerzy; Lemanski, Dariusz; Foks-Ryznar, Anna; Nogas, Pawel; Dunst, Piotr

    2013-04-01

    In this work the clock parameters determination of several timing receivers TTS-4 (AOS), ASHTECH Z-XII3T (OP, ORB, PTB, USNO) and SEPTENTRIO POLARX4TR (ORB, since February 11, 2012) by use of the Precise Point Positioning (PPP) technique were presented. The clock parameters were determined for several time links based on the data delivered by time and frequency laboratories mentioned above. The computations cover the period from January 1 to December 31, 2012 and were performed in two modes with 7-day and one-month solution for all links. All RINEX data files which include phase and code GPS data were recorded in 30-second intervals. All calculations were performed by means of Natural Resource Canada's GPS Precise Point Positioning (GPS-PPP) software based on high-quality precise satellite coordinates and satellite clock delivered by IGS as the final products. The used independent PPP technique is a very powerful and simple method which allows for better control of antenna positions in AOS and a verification of other time transfer techniques like GPS CV, GLONASS CV and TWSTFT. The PPP technique is also a very good alternative for calibration of a glass fiber link PL-AOS realized at present by AOS. Currently PPP technique is one of the main time transfer methods used at AOS what considerably improve and strengthen the quality of the Polish time scales UTC(AOS), UTC(PL), and TA(PL). KEY-WORDS: Precise Point Positioning, time transfer, IGS products, GNSS, time scales.

  19. Precise Point Positioning with the BeiDou Navigation Satellite System

    PubMed Central

    Li, Min; Qu, Lizhong; Zhao, Qile; Guo, Jing; Su, Xing; Li, Xiaotao

    2014-01-01

    By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS) around the World. The Position and Navigation Data Analyst (PANDA) software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP). The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems. PMID:24406856

  20. Precise point positioning with the BeiDou navigation satellite system.

    PubMed

    Li, Min; Qu, Lizhong; Zhao, Qile; Guo, Jing; Su, Xing; Li, Xiaotao

    2014-01-01

    By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS) around the World. The Position and Navigation Data Analyst (PANDA) software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP). The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems. PMID:24406856

  1. Precise point positioning with quad-constellations: GPS, BeiDou, GLONASS and Galileo

    NASA Astrophysics Data System (ADS)

    Cai, Changsheng; Gao, Yang; Pan, Lin; Zhu, Jianjun

    2015-07-01

    Multi-constellation GNSS precise point positioning (PPP) first became feasible back to 2007 but with only two constellations, namely GPS and GLONASS. With the availability of more satellites and precise orbit and clock products from BeiDou and Galileo, it is possible now to investigate PPP with four constellations, namely GPS, BeiDou, GLONASS and Galileo. This research aims at investigating the quad-constellation PPP for position determination and analyzing its positioning performance. A quad-constellation PPP model is developed to simultaneously process the observations from all the four GNSS systems. The developed model is also applicable to the PPP processing with observations from single, dual or triple constellations. The analysis on PPP accuracy and convergence time is conducted based on data processing results from both static and kinematic tests of single-constellation and multi-constellations. The three-hour static positioning results indicate that the BeiDou-only PPP accuracy is worse than the GPS-only PPP. The RMSs of position errors for BeiDou-only PPP are 5.2 cm, 2.7 cm and 8.3 cm in east, north and up directions while the ones for GPS-only PPP are 3.9 cm, 1.6 cm and 5.7 cm. The GPS/BeiDou PPP improves the positioning accuracy by 28%, 6% and 7% and reduces the convergence time by 26%, 13% and 14% over the GPS-only PPP in three coordinate components, respectively. The GPS/GLONASS PPP achieves slightly better performance than the GPS/BeiDou PPP. The triple-constellation PPP further increases the positioning accuracy and decreases the convergence time over the dual-constellation PPP. The improvement of positioning performance is not significant after adding Galileo due to currently limited number of satellites. Similar to the static positioning, the quad-constellation kinematic PPP also significantly improves the positioning performance in contrast with single-constellation and dual-constellations. The time varying characteristics of the time differences between the four systems are also investigated. The results indicate that the system time differences of GPS with BeiDou, GLONASS and Galileo are very stable over time with STD values of better than 1.1 ns.

  2. Satellite- and Epoch Differenced Precise Point Positioning Based on a Regional Augmentation Network

    PubMed Central

    Li, Haojun; Chen, Junping; Wang, Jiexian; Wu, Bin

    2012-01-01

    Precise Point Positioning (PPP) has been demonstrated as a simple and effective approach for user positioning. The key issue in PPP is how to shorten convergence time and improve positioning efficiency. Recent researches mainly focus on the ambiguity resolution by correcting residual phase errors at a single station. The success of this approach (referred to hereafter as NORM-PPP) is subject to how rapidly one can fix wide-lane and narrow-lane ambiguities to achieve the first ambiguity-fixed solution. The convergence time of NORM-PPP is receiver type dependent, and normally takes 15–20 min. Different from the general algorithm and theory by which the float ambiguities are estimated and the integer ambiguities are fixed, we concentrate on a differential PPP approach: the satellite- and epoch differenced (SDED) approach. In general, the SDED approach eliminates receiver clocks and ambiguity parameters and thus avoids the complicated residual phase modeling procedure. As a further development of the SDED approach, we use a regional augmentation network to derive tropospheric delay and remaining un-modeled errors at user sites. By adding these corrections and applying the Robust estimation, the weak mathematic properties due to the ED operation is much improved. Implementing this new approach, we need only two epochs of data to achieve PPP positioning converging to centimeter-positioning accuracy. Using seven days of GPS data at six CORS stations in Shanghai, we demonstrate the success rate, defined as the case when three directions converging to desired positioning accuracy of 10 cm, reaches 100% when the interval between the two epochs is longer than 15 min. Comparing the results of 15 min' interval to that of 10 min', it is observed that the position RMS improves from 2.47, 3.95, 5.78 cm to 2.21, 3.93, 4.90 cm in the North, East and Up directions, respectively. Combining the SDED coordinates at the starting point and the ED relative coordinates thereafter, we demonstrate the performance of RTK PPP with standard deviation of 0.80, 1.34, 0.97 cm in the North, East and Up directions. PMID:22969358

  3. Single-point position and transition defects in continuous time quantum walks

    PubMed Central

    Li, Z. J.; Wang, J. B.

    2015-01-01

    We present a detailed analysis of continuous time quantum walks (CTQW) with both position and transition defects defined at a single point in the line. Analytical solutions of both traveling waves and bound states are obtained, which provide valuable insight into the dynamics of CTQW. The number of bound states is found to be critically dependent on the defect parameters, and the localized probability peaks can be readily obtained by projecting the state vector of CTQW on to these bound states. The interference between two bound states are also observed in the case of a transition defect. The spreading of CTQW probability over the line can be finely tuned by varying the position and transition defect parameters, offering the possibility of precision quantum control of the system. PMID:26323855

  4. GPS/GLONASS Combined Precise Point Positioning with Receiver Clock Modeling

    PubMed Central

    Wang, Fuhong; Chen, Xinghan; Guo, Fei

    2015-01-01

    Research has demonstrated that receiver clock modeling can reduce the correlation coefficients among the parameters of receiver clock bias, station height and zenith tropospheric delay. This paper introduces the receiver clock modeling to GPS/GLONASS combined precise point positioning (PPP), aiming to better separate the receiver clock bias and station coordinates and therefore improve positioning accuracy. Firstly, the basic mathematic models including the GPS/GLONASS observation equations, stochastic model, and receiver clock model are briefly introduced. Then datasets from several IGS stations equipped with high-stability atomic clocks are used for kinematic PPP tests. To investigate the performance of PPP, including the positioning accuracy and convergence time, a week of (1–7 January 2014) GPS/GLONASS data retrieved from these IGS stations are processed with different schemes. The results indicate that the positioning accuracy as well as convergence time can benefit from the receiver clock modeling. This is particularly pronounced for the vertical component. Statistic RMSs show that the average improvement of three-dimensional positioning accuracy reaches up to 30%–40%. Sometimes, it even reaches over 60% for specific stations. Compared to the GPS-only PPP, solutions of the GPS/GLONASS combined PPP are much better no matter if the receiver clock offsets are modeled or not, indicating that the positioning accuracy and reliability are significantly improved with the additional GLONASS satellites in the case of insufficient number of GPS satellites or poor geometry conditions. In addition to the receiver clock modeling, the impacts of different inter-system timing bias (ISB) models are investigated. For the case of a sufficient number of satellites with fairly good geometry, the PPP performances are not seriously affected by the ISB model due to the low correlation between the ISB and the other parameters. However, the refinement of ISB model weakens the correlation between coordinates and ISB estimates and finally enhance the PPP performance in the case of poor observation conditions. PMID:26134106

  5. GPS/GLONASS Combined Precise Point Positioning with Receiver Clock Modeling.

    PubMed

    Wang, Fuhong; Chen, Xinghan; Guo, Fei

    2015-01-01

    Research has demonstrated that receiver clock modeling can reduce the correlation coefficients among the parameters of receiver clock bias, station height and zenith tropospheric delay. This paper introduces the receiver clock modeling to GPS/GLONASS combined precise point positioning (PPP), aiming to better separate the receiver clock bias and station coordinates and therefore improve positioning accuracy. Firstly, the basic mathematic models including the GPS/GLONASS observation equations, stochastic model, and receiver clock model are briefly introduced. Then datasets from several IGS stations equipped with high-stability atomic clocks are used for kinematic PPP tests. To investigate the performance of PPP, including the positioning accuracy and convergence time, a week of (1-7 January 2014) GPS/GLONASS data retrieved from these IGS stations are processed with different schemes. The results indicate that the positioning accuracy as well as convergence time can benefit from the receiver clock modeling. This is particularly pronounced for the vertical component. Statistic RMSs show that the average improvement of three-dimensional positioning accuracy reaches up to 30%-40%. Sometimes, it even reaches over 60% for specific stations. Compared to the GPS-only PPP, solutions of the GPS/GLONASS combined PPP are much better no matter if the receiver clock offsets are modeled or not, indicating that the positioning accuracy and reliability are significantly improved with the additional GLONASS satellites in the case of insufficient number of GPS satellites or poor geometry conditions. In addition to the receiver clock modeling, the impacts of different inter-system timing bias (ISB) models are investigated. For the case of a sufficient number of satellites with fairly good geometry, the PPP performances are not seriously affected by the ISB model due to the low correlation between the ISB and the other parameters. However, the refinement of ISB model weakens the correlation between coordinates and ISB estimates and finally enhance the PPP performance in the case of poor observation conditions. PMID:26134106

  6. Tightly Coupled Integration of Ionosphere-Constrained Precise Point Positioning and Inertial Navigation Systems

    PubMed Central

    Gao, Zhouzheng; Zhang, Hongping; Ge, Maorong; Niu, Xiaoji; Shen, Wenbin; Wickert, Jens; Schuh, Harald

    2015-01-01

    The continuity and reliability of precise GNSS positioning can be seriously limited by severe user observation environments. The Inertial Navigation System (INS) can overcome such drawbacks, but its performance is clearly restricted by INS sensor errors over time. Accordingly, the tightly coupled integration of GPS and INS can overcome the disadvantages of each individual system and together form a new navigation system with a higher accuracy, reliability and availability. Recently, ionosphere-constrained (IC) precise point positioning (PPP) utilizing raw GPS observations was proven able to improve both the convergence and positioning accuracy of the conventional PPP using ionosphere-free combined observations (LC-PPP). In this paper, a new mode of tightly coupled integration, in which the IC-PPP instead of LC-PPP is employed, is implemented to further improve the performance of the coupled system. We present the detailed mathematical model and the related algorithm of the new integration of IC-PPP and INS. To evaluate the performance of the new tightly coupled integration, data of both airborne and vehicle experiments with a geodetic GPS receiver and tactical grade inertial measurement unit are processed and the results are analyzed. The statistics show that the new approach can further improve the positioning accuracy compared with both IC-PPP and the tightly coupled integration of the conventional PPP and INS. PMID:25763647

  7. Tightly coupled integration of ionosphere-constrained precise point positioning and inertial navigation systems.

    PubMed

    Gao, Zhouzheng; Zhang, Hongping; Ge, Maorong; Niu, Xiaoji; Shen, Wenbin; Wickert, Jens; Schuh, Harald

    2015-01-01

    The continuity and reliability of precise GNSS positioning can be seriously limited by severe user observation environments. The Inertial Navigation System (INS) can overcome such drawbacks, but its performance is clearly restricted by INS sensor errors over time. Accordingly, the tightly coupled integration of GPS and INS can overcome the disadvantages of each individual system and together form a new navigation system with a higher accuracy, reliability and availability. Recently, ionosphere-constrained (IC) precise point positioning (PPP) utilizing raw GPS observations was proven able to improve both the convergence and positioning accuracy of the conventional PPP using ionosphere-free combined observations (LC-PPP). In this paper, a new mode of tightly coupled integration, in which the IC-PPP instead of LC-PPP is employed, is implemented to further improve the performance of the coupled system. We present the detailed mathematical model and the related algorithm of the new integration of IC-PPP and INS. To evaluate the performance of the new tightly coupled integration, data of both airborne and vehicle experiments with a geodetic GPS receiver and tactical grade inertial measurement unit are processed and the results are analyzed. The statistics show that the new approach can further improve the positioning accuracy compared with both IC-PPP and the tightly coupled integration of the conventional PPP and INS. PMID:25763647

  8. Stochastic modelling considering ionospheric scintillation effects on GNSS relative and point positioning

    NASA Astrophysics Data System (ADS)

    da Silva, Helosa Alves; de Oliveira Camargo, Paulo; Galera Monico, Joo Francisco; Aquino, Marcio; Marques, Haroldo Antonio; de Franceschi, Giorgiana; Dodson, Alan

    2010-05-01

    Global Navigation Satellite Systems (GNSS), in particular the Global Positioning System (GPS), have been widely used for high accuracy geodetic positioning. The Least Squares functional models related to the GNSS observables have been more extensively studied than the corresponding stochastic models, given that the development of the latter is significantly more complex. As a result, a simplified stochastic model is often used in GNSS positioning, which assumes that all the GNSS observables are statistically independent and of the same quality, i.e. a similar variance is assigned indiscriminately to all of the measurements. However, the definition of the stochastic model may be approached from a more detailed perspective, considering specific effects affecting each observable individually, as for example the effects of ionospheric scintillation. These effects relate to phase and amplitude fluctuations in the satellites signals that occur due to diffraction on electron density irregularities in the ionosphere and are particularly relevant at equatorial and high latitude regions, especially during periods of high solar activity. As a consequence, degraded measurement quality and poorer positioning accuracy may result. This paper takes advantage of the availability of specially designed GNSS receivers that provide parameters indicating the level of phase and amplitude scintillation on the signals, which therefore can be used to mitigate these effects through suitable improvements in the least squares stochastic model. The stochastic model considering ionospheric scintillation effects has been implemented following the approach described in Aquino et al. (2009), which is based on the computation of weights derived from the scintillation sensitive receiver tacking models of Conker et al. (2003). The methodology and algorithms to account for these effects in the stochastic model are described and results of experiments where GPS data were processed in both a relative and a point positioning mode are presented and discussed. Two programs have been developed to enable the analyses: GPSeq (currently under development at the FCT/UNESP Sao Paulo State University - Brazil) and PP_Sc (developed in a collaborative project between FCT/UNESP and Nottingham University - UK). The point positioning approach is based on an epoch by epoch solution, whereas the relative positioning on an accumulated solution using a Kalman Filter and the LAMBDA method to solve the Double Differences ambiguities. Additionally to the use of an improved stochastic model, all data processing in this paper were performed using an option implemented in both programs, to estimate, for each observable, an individual ionospheric parameter modelled as a stochastic process, using either the white noise or the random walk correlation models. Data from a network of GPS Ionospheric Scintillation and TEC Monitor (GISTM) receivers set up in Northern Europe as part of the ISACCO project (De Franceschi et al., 2006) were used in the experiments. The point positioning results have shown improvements of the order of 45% in height accuracy when the proposed stochastic model is applied. In the static relative positioning, improvements of the order of 50%, also in height accuracy, have been reached under moderate to strong scintillation conditions. These and further results are discussed in this paper.

  9. Ophthalmic manifestations postlightning strike.

    PubMed

    Dhillon, Permesh Singh; Gupta, Mohit

    2015-01-01

    Various ophthalmic complications affecting the anterior and posterior segments have been identified due to lightning strike. We report the first case of an indirect lightning-induced full thickness macular hole formation in the UK as evidenced by slit lamp examination and optical coherence tomography (OCT) scan in a 77-year-old woman presenting with sudden visual loss in her right eye and thermal skin injury affecting her scalp. Her best corrected visual acuities were LogMAR 0.46 and 0.12 in the right and left eyes, respectively. There were no other ocular manifestations observed in either eye. She was initially managed conservatively with non-steroidal anti-inflammatory drug eye drops but surgery was later advised due to minimal changes in the visual acuity and macular hole on follow-up. OCT scanning is important in diagnosing macular holes, which usually warrant surgical intervention. PMID:25827914

  10. Triple positive solutions of three-point boundary value problems for p-Laplacian dynamic equations on time scales

    NASA Astrophysics Data System (ADS)

    Hong, Shihuang

    2007-09-01

    In this paper, we present sufficient conditions for the existence of at least three positive solutions of three-point boundary value problems for p-Laplacian dynamic equations on a time scale. To show our main results, we apply a new fixed point theorem due to Avery and Peterson [Three positive fixed points of nonlinear operators on ordered Banach spaces, Comput. Math. Appl. 42 (2001) 313-322].

  11. Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities

    PubMed Central

    Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

    2014-01-01

    Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901

  12. Near-real-time regional troposphere models for the GNSS precise point positioning technique

    NASA Astrophysics Data System (ADS)

    Hadas, T.; Kaplon, J.; Bosy, J.; Sierny, J.; Wilgan, K.

    2013-05-01

    The GNSS precise point positioning (PPP) technique requires high quality product (orbits and clocks) application, since their error directly affects the quality of positioning. For real-time purposes it is possible to utilize ultra-rapid precise orbits and clocks which are disseminated through the Internet. In order to eliminate as many unknown parameters as possible, one may introduce external information on zenith troposphere delay (ZTD). It is desirable that the a priori model is accurate and reliable, especially for real-time application. One of the open problems in GNSS positioning is troposphere delay modelling on the basis of ground meteorological observations. Institute of Geodesy and Geoinformatics of Wroclaw University of Environmental and Life Sciences (IGG WUELS) has developed two independent regional troposphere models for the territory of Poland. The first one is estimated in near-real-time regime using GNSS data from a Polish ground-based augmentation system named ASG-EUPOS established by Polish Head Office of Geodesy and Cartography (GUGiK) in 2008. The second one is based on meteorological parameters (temperature, pressure and humidity) gathered from various meteorological networks operating over the area of Poland and surrounding countries. This paper describes the methodology of both model calculation and verification. It also presents results of applying various ZTD models into kinematic PPP in the post-processing mode using Bernese GPS Software. Positioning results were used to assess the quality of the developed models during changing weather conditions. Finally, the impact of model application to simulated real-time PPP on precision, accuracy and convergence time is discussed.

  13. Foot-strike pattern and performance in a marathon

    PubMed Central

    Kasmer, Mark E.; Liu, Xue-cheng; Roberts, Kyle G.; Valadao, Jason M.

    2016-01-01

    Purpose To: 1) determine prevalence of heel-strike in a mid-size city marathon, 2) determine if there is an association between foot-strike classification and race performance, and 3) determine if there is an association between foot-strike classification and gender. Methods Foot-strike classification (fore-foot strike, mid-foot strike, heel strike, or split-strike), gender, and rank (position in race) were recorded at the 8.1 kilometer (km) mark for 2,112 runners at the 2011 Milwaukee Lakefront Marathon. Results 1,991 runners were classified by foot-strike pattern, revealing a heel-strike prevalence of 93.67% (n=1,865). A significant difference between foot-strike classification and performance was found using a Kruskal-Wallis test (p < 0.0001), with more elite performers being less likely to heel-strike. No significant difference between foot-strike classification and gender was found using a Fisher’s exact test. Additionally, subgroup analysis of the 126 non-heel strikers found no significant difference between shoe wear and performance using a Kruskal-Wallis test. Conclusions The high prevalence of heel-striking observed in this study reflects the foot-strike pattern of the majority of mid- to long-distance runners and more importantly, may predict their injury profile based on the biomechanics of a heel strike running pattern. This knowledge can aid the clinician in the appropriate diagnosis, management, and training modifications of the injured runner. PMID:23006790

  14. Real-time Precise Point Positioning with Ambiguity Resolution for Geosciences

    NASA Astrophysics Data System (ADS)

    Geng, J.; Meng, X.; Teferle, F. N.; Dodson, A. H.; Ge, M.; Shi, C.; Liu, J.

    2009-04-01

    Real-time provision of information on large scale crustal deformation during an earthquake can be crucial in assessing property damage and managing relief operations. Moreover, such a real-time monitoring system may even lead to the accurate prediction of earthquakes in future and help the subsequent studies on the mechanism involved. During the past two decades, Global Positioning System (GPS) measurements have been extensively applied to investigate such processes in the geosciences. Precise point positioning (PPP) using GPS based on single stations can achieve comparable accuracies to conventional relative positioning, when precise satellite orbits and clocks, and Earth rotation products are used. Thus, PPP does not need any reference stations to achieve high positioning accuracy, e.g. at the millimetre level in static and centimetre level in kinematic applications. This has both technical and economic advantages and may be the only feasible option in some specific applications such as Tsunami early warning systems. However, unlike relative positioning, PPP suffers from unresolved integer ambiguities, which prevented further accuracy improvements within short observation periods or in real-time. On account of the great potential of PPP, we developed a prototype real-time PPP system which also employs ambiguity resolution at a single station. This development is based on the PANDA (Positioning And Navigation Data Analyst) software, which was originally developed at Wuhan University in China, and has been significantly refined by the authors. To assess this system, about 30 stations from the EUREF Permanent Network Internet Protocol (EUREF-IP) pilot project are used to produce the real-time satellite clocks, with satellite orbits and Earth rotation parameters (ERP) fixed to the predicted part of the IGS (International GNSS Service) ultra-rapid products. This is followed by the estimation of the uncalibrated hardware delays (UHD), which are crucial in resolving the ambiguities. Finally, all products (clocks, orbits, UHDs and ERPs) are provided in real-time to allow PPP with ambiguity resolution. Through the simulation of this prototype real-time PPP system, we show that significant accuracy improvements can be achieved, which are of significance to real-time applications in the geosciences.

  15. Where Lightning Strikes

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lightning. It avoids the ocean, but likes Florida. It's attracted to the Himalayas and even more so to central Africa. And lightning almost never strikes the north or south poles. These are just a few of the things NASA scientists have learned using satellites to monitor worldwide lightning. 'For the first time, we've been able to map the global distribution of lightning, noting its variation as a function of latitude, longitude and time of year,' says Hugh Christian, project leader for the National Space Science and Technology Center's (NSSTC's) lightning team at NASA's Marshall Space Flight Center. This new perspective on lightning is possible thanks to two satellite-based detectors: the Optical Transient Detector (OTD) and the Lightning Imaging Sensor (LIS). 'The OTD and the LIS are two optical sensors that we've flown in lower Earth orbit,' says Christian, whose team developed the sensors. 'The OTD was launched in 1995 and we got five good years out of it. The LIS was launched on the Tropical Rainfall Measuring Mission satellite in 1997 and it's still going strong.' 'Basically, these optical sensors use high-speed cameras to look for changes in the tops of clouds, changes your eyes can't see,' he explains. By analyzing a narrow wavelength band around 777 nanometers-which is in the near-infrared region of the spectrum-they can spot brief lightning flashes even under daytime conditions. For the full story, visit Science@NASA Image courtesy NSSTC Lightning Team

  16. Public Sector Bargaining and Strikes. Second Edition.

    ERIC Educational Resources Information Center

    Public Service Research Council, Vienna, VA.

    It is the opinion of the authors of this position paper that collective bargaining in the public sector causes an increase in strikes and employee unrest, resulting in a diminution of public services. The authors assert that public employee collective bargaining means giving unions the power to control government through intimidation of the…

  17. X-point-position-dependent intrinsic rotation in the edge of TCV

    NASA Astrophysics Data System (ADS)

    Stoltzfus-Dueck, Timothy

    2014-10-01

    A simple transport-based theoretical model predicts that intrinsic toroidal rotation in the tokamak edge should depend strongly on RX, the major-radial position of the X-point, including a sign change to counter-current rotation for adequately outboard X-point. To test the prediction, an RX scan was conducted in Ohmic L-mode shots on TCV, in both USN and LSN configurations. The strong linear dependence on RX was experimentally observed, with quantitative magnitude corresponding to a realistic value for the theory's corresponding input parameter. Although peaked rotation profiles complicate the comparison of absolute rotation values, the data is consistent with the predicted sign change. The core rotation profile shifted fairly rigidly with the edge rotation value, maintaining a relatively constant core rotation gradient. Core rotation reversals, triggered accidentally in a few shots, had little effect on the edge rotation velocity. Edge rotation was modestly more counter-current in USN than LSN discharges. This work was supported in part by the Swiss National Science Foundation and in part by the European Atomic Energy Community, and is subject to the provisions of the European Fusion Development Agreement.

  18. Clusterless Decoding of Position from Multiunit Activity Using a Marked Point Process Filter.

    PubMed

    Deng, Xinyi; Liu, Daniel F; Kay, Kenneth; Frank, Loren M; Eden, Uri T

    2015-07-01

    Point process filters have been applied successfully to decode neural signals and track neural dynamics. Traditionally these methods assume that multiunit spiking activity has already been correctly spike-sorted. As a result, these methods are not appropriate for situations where sorting cannot be performed with high precision, such as real-time decoding for brain-computer interfaces. Because the unsupervised spike-sorting problem remains unsolved, we took an alternative approach that takes advantage of recent insights into clusterless decoding. Here we present a new point process decoding algorithm that does not require multiunit signals to be sorted into individual units. We use the theory of marked point processes to construct a function that characterizes the relationship between a covariate of interest (in this case, the location of a rat on a track) and features of the spike waveforms. In our example, we use tetrode recordings, and the marks represent a four-dimensional vector of the maximum amplitudes of the spike waveform on each of the four electrodes. In general, the marks may represent any features of the spike waveform. We then use Bayes's rule to estimate spatial location from hippocampal neural activity. We validate our approach with a simulation study and experimental data recorded in the hippocampus of a rat moving through a linear environment. Our decoding algorithm accurately reconstructs the rat's position from unsorted multiunit spiking activity. We then compare the quality of our decoding algorithm to that of a traditional spike-sorting and decoding algorithm. Our analyses show that the proposed decoding algorithm performs equivalent to or better than algorithms based on sorted single-unit activity. These results provide a path toward accurate real-time decoding of spiking patterns that could be used to carry out content-specific manipulations of population activity in hippocampus or elsewhere in the brain. PMID:25973549

  19. Clusterless Decoding of Position From Multiunit Activity Using A Marked Point Process Filter

    PubMed Central

    Deng, Xinyi; Liu, Daniel F.; Kay, Kenneth; Frank, Loren M.; Eden, Uri T.

    2016-01-01

    Point process filters have been applied successfully to decode neural signals and track neural dynamics. Traditionally, these methods assume that multiunit spiking activity has already been correctly spike-sorted. As a result, these methods are not appropriate for situations where sorting cannot be performed with high precision such as real-time decoding for brain-computer interfaces. As the unsupervised spike-sorting problem remains unsolved, we took an alternative approach that takes advantage of recent insights about clusterless decoding. Here we present a new point process decoding algorithm that does not require multiunit signals to be sorted into individual units. We use the theory of marked point processes to construct a function that characterizes the relationship between a covariate of interest (in this case, the location of a rat on a track) and features of the spike waveforms. In our example, we use tetrode recordings, and the marks represent a four-dimensional vector of the maximum amplitudes of the spike waveform on each of the four electrodes. In general, the marks may represent any features of the spike waveform. We then use Bayes’ rule to estimate spatial location from hippocampal neural activity. We validate our approach with a simulation study and with experimental data recorded in the hippocampus of a rat moving through a linear environment. Our decoding algorithm accurately reconstructs the rat’s position from unsorted multiunit spiking activity. We then compare the quality of our decoding algorithm to that of a traditional spike-sorting and decoding algorithm. Our analyses show that the proposed decoding algorithm performs equivalently or better than algorithms based on sorted single-unit activity. These results provide a path toward accurate real-time decoding of spiking patterns that could be used to carry out content-specific manipulations of population activity in hippocampus or elsewhere in the brain. PMID:25973549

  20. Integration of GPS Precise Point Positioning and MEMS-Based INS Using Unscented Particle Filter

    PubMed Central

    Abd Rabbou, Mahmoud; El-Rabbany, Ahmed

    2015-01-01

    Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman filter (EKF) is commonly used as the estimation filter, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. Particle filtering (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented particle filter (UPF), is utilized, which combines the unscented Kalman filter (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed filter is examined and compared with traditional estimation filters, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all filters produce comparable results when the GPS measurement updates are available. PMID:25815446

  1. Integration of GPS precise point positioning and MEMS-based INS using unscented particle filter.

    PubMed

    Abd Rabbou, Mahmoud; El-Rabbany, Ahmed

    2015-01-01

    Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman filter (EKF) is commonly used as the estimation filter, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. Particle filtering (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented particle filter (UPF), is utilized, which combines the unscented Kalman filter (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed filter is examined and compared with traditional estimation filters, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all filters produce comparable results when the GPS measurement updates are available. PMID:25815446

  2. Striking Pay Dirt!

    ERIC Educational Resources Information Center

    Conger, George

    1984-01-01

    The conception and development of a plan to lease community college property for oil drilling is described, emphasizing the governing board's role in the process. The risks, uncertainties, relationships with local fuel companies, and positive public perception are discussed. (MSE)

  3. Ambiguity resolution in precise point positioning with hourly data for global single receiver

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohong; Li, Pan; Guo, Fei

    2013-01-01

    Integer ambiguity resolution (IAR) can improve precise point positioning (PPP) performance significantly. IAR for PPP became a highlight topic in global positioning system (GPS) community in recent years. More and more researchers focus on this issue. Progress has been made in the latest years. In this paper, we aim at investigating and demonstrating the performance of a global zero-differenced (ZD) PPP IAR service for GPS users by providing routine ZD uncalibrated fractional offsets (UFOs) for wide-lane and narrow-lane. Data sets from all IGS stations collected on DOY 1, 100, 200 and 300 of 2010 are used to validate and demonstrate this global service. Static experiment results show that an accuracy better than 1 cm in horizontal and 1-2 cm in vertical could be achieved in ambiguity-fixed PPP solution with only hourly data. Compared with PPP float solution, an average improvement reaches 58.2% in east, 28.3% in north and 23.8% in vertical for all tested stations. Results of kinematic experiments show that the RMS of kinematic PPP solutions can be improved from 21.6, 16.6 and 37.7 mm to 12.2, 13.3 and 34.3 mm for the fixed solutions in the east, north and vertical components, respectively. Both static and kinematic experiments show that wide-lane and narrow-lane UFO products of all satellites can be generated and provided in a routine way accompanying satellite orbit and clock products for the PPP user anywhere around the world, to obtain accurate and reliable ambiguity-fixed PPP solutions.

  4. A simplified and unified model of multi-GNSS precise point positioning

    NASA Astrophysics Data System (ADS)

    Chen, Junping; Zhang, Yize; Wang, Jungang; Yang, Sainan; Dong, Danan; Wang, Jiexian; Qu, Weijing; Wu, Bin

    2015-01-01

    Additional observations from other GNSS s can augment GPS precise point positioning (PPP) for improved positioning accuracy, reliability and availability. Traditional multi-GNSS PPP model requires the estimation of inter-system bias (ISB) parameter. Based on the scaled sensitivity matrix (SSM) method, a quantitative approach for assessing parameter assimilation, we theoretically prove that the ISB parameter is not correlated with coordinate parameters and it can be assimilated into clock and ambiguity parameters. Thus, removing ISB from multi-GNSS PPP model does not affect coordinate estimation. Based on this analysis, we develop a simplified and unified model for multi-GNSS PPP, where ISB parameter does not need to be estimated and observations from different GNSS systems are treated in a unified way. To verify the new model, we implement the algorithm to the self-developed software to process 1 year GPS/GLONASS data of 53 IGS (International GNSS Service) worldwide stations and 1 month GPS/BDS data of 15 IGS MGEX (Multi-GNSS Experiment) stations. Two types of GPS/GLONASS and GPS/BDS combined PPP solution are performed, one is based on traditional model and the other implements the new model. RMSs of coordinate differences between the two type of solutions are few ?m for daily static PPP and less than 0.02 mm for GPS/GLONASS kinematic PPP in the North, East and Up components, respectively. Considering the millimeter-level precision of current GNSS PPP solutions, these statistics demonstrate equivalent performance of the two solution types.

  5. A Comparison of Real-Time Precise Point Positioning Zenith Total Delay Estimates

    NASA Astrophysics Data System (ADS)

    Ahmed, F.; Vaclavovic, P.; Dousa, J.; Teferle, F. N.; Laurichesse, D.; Bingley, R.

    2013-12-01

    The use of observations from Global Navigation Satellite Systems (GNSS) in operational meteorology is increasing worldwide due to the continuous evolution of GNSS. The assimilation of near real-time (NRT) GNSS-derived zenith total delay (ZTD) estimates into local, regional and global scale numerical weather prediction (NWP) models is now in operation at a number of meteorological institutions. The development of NWP models with high update cycles for now-casting and monitoring of extreme weather events in recent years, requires the estimation of ZTD with minimal latencies, i.e. from 5 to 10 minutes, while maintaining an adequate level of accuracy for these. The availability of real-time (RT) observations and products from the IGS RT service and associated analysis centers make it possible to compute precise point positioning (PPP) solutions in RT, which provide ZTD along with position estimates. This study presents a comparison of the RT ZTD estimates from three different PPP software packages (G-Nut/Tefnut, BNC2.7 and PPP-Wizard) to the state-of-the-art IGS Final Troposphere Product employing PPP in the Bernese GPS Software. Overall, the ZTD time series obtained by the software packages agree fairly well with the estimates following the variations of the other solutions, but showing various biases with the reference. After correction of these the RMS differences are at the order of 0.01 m. The application of PPP ambiguity resolution in one solution or the use of different RT product streams shows little impact on the ZTD estimates.

  6. On biases in precise point positioning with multi-constellation and multi-frequency GNSS data

    NASA Astrophysics Data System (ADS)

    El-Mowafy, A.; Deo, M.; Rizos, C.

    2016-03-01

    Various types of biases in Global Navigation Satellite System (GNSS) data preclude integer ambiguity fixing and degrade solution accuracy when not being corrected during precise point positioning (PPP). In this contribution, these biases are first reviewed, including satellite and receiver hardware biases, differential code biases, differential phase biases, initial fractional phase biases, inter-system receiver time biases, and system time scale offset. PPP models that take account of these biases are presented for two cases using ionosphere-free observations. The first case is when using primary signals that are used to generate precise orbits and clock corrections. The second case applies when using additional signals to the primary ones. In both cases, measurements from single and multiple constellations are addressed. It is suggested that the satellite-related code biases be handled as calibrated quantities that are obtained from multi-GNSS experiment products and the fractional phase cycle biases obtained from a network to allow for integer ambiguity fixing. Some receiver-related biases are removed using between-satellite single differencing, whereas other receiver biases such as inter-system biases are lumped with differential code and phase biases and need to be estimated. The testing results show that the treatment of biases significantly improves solution convergence in the float ambiguity PPP mode, and leads to ambiguity-fixed PPP within a few minutes with a small improvement in solution precision.

  7. Stevens Institute of Technology: After the Strike, Still Unsettled

    ERIC Educational Resources Information Center

    Walsh, John

    1977-01-01

    Discusses disputed points of a strike of faculty at Stevens Institute of Technology, Hoboken, NJ. Reviews history of the development of the conflict between faculty and administration. Reports the current status of the strike, in which the American Association of University Professors (AAUP) acts as bargaining agent. (CS)

  8. Positions of equilibrium points for dust particles in the circular restricted three-body problem with radiation

    NASA Astrophysics Data System (ADS)

    Pástor, P.

    2014-11-01

    For a body with negligible mass moving in the gravitational field of a star with one planet in a circular orbit (the circular restricted three-body problem), five equilibrium points exist and are known as the Lagrangian points. The positions of the Lagrangian points are not valid for dust particles because in the derivation of the Lagrangian points it is assumed that no other forces besides the gravitation act on the body with negligible mass. Here, we determined positions of the equilibrium points for the dust particles in the circular restricted three-body problem with radiation. The equilibrium points are located on curves connecting the Lagrangian points in the circular restricted three-body problem. The equilibrium points for Jupiter are distributed in large interval of heliocentric distances due to its large mass. The equilibrium points for the Earth explain a cloud of dust particles trailing the Earth observed with the Spitzer Space Telescope. The dust particles moving in the equilibrium points are distributed in interplanetary space according to their properties.

  9. Predicting atmospheric delays for rapid ambiguity resolution in precise point positioning

    NASA Astrophysics Data System (ADS)

    Li, Xingxing; Zhang, Xiaohong; Guo, Fei

    2014-09-01

    Integer ambiguity resolution in precise point positioning (PPP) can shorten the initialization and re-initialization time, and ambiguity-fixed PPP solutions are also more reliable and accurate than ambiguity-float PPP solutions. However, signal interruptions are unavoidable in practical applications, particularly while operating in urban areas. Such signal interruptions can cause discontinuity of carrier phase arc, which introduces new integer ambiguities. Usually it will take approximately 15 min of continuous tracking to a reasonable number of satellites to fix new integer ambiguities. In many applications, it is impractical for a PPP user to wait for such a long time for the re-initialization. In this paper, a method for rapid ambiguity fixing in PPP is developed to avoid such a long re-initialization time. Firstly, the atmospheric delays were estimated epoch by epoch from ambiguity-fixed PPP solutions before the data gap or cycle slip occurs. A random walk procedure is then applied to predict the atmospheric delays accurately over a short time span. The predicted atmospheric delays then can be used to correct the observations which suffer from signal interruptions. Finally, the new ambiguities can be fixed with a distinct WL-LX-L3 (here LX denotes either of L1, L2) cascade ambiguity resolution strategy. Comprehensive experiments have demonstrated that the proposed method and strategy can fix zero-difference integer ambiguities successfully with only a single-epoch observation immediately after a short data gap. This technique works even when all satellites are interrupted at the same time. The duration of data gap bridged by this technique could be possibly extended if a more precise atmospheric delay prediction is found or on-the-fly (OTF) technology is applied. Based on the proposed method, real-time PPP with integer ambiguity fixing becomes more feasible in practice.

  10. Slant Wet Delays from GNSS observations - Precise Point Positioning vs. Double Difference Approach

    NASA Astrophysics Data System (ADS)

    Moeller, Gregor; Weber, Robert

    2015-04-01

    The tropospheric parameter SWD (Slant Wet Delay) is the path delay caused by the highly variable amount of humidity in the atmosphere at altitudes below 12 km. It can be derived from Numerical Weather Predication data or even more precisely from dual- or multi-frequency observations of a regional GNSS reference network. In order to find the most adequate processing strategy dual GNSS observations of a small network of reference stations were simulated and tropospheric parameters were estimated in Precise Point Positioning (PPP) and in Double Difference (DD) mode. In DD mode the integer character of the phase ambiguities remains which allows to fix them to their true values and to obtain the tropospheric zenith delay as well as north and east (N/E) gradients with highest precision over very short time periods. In PPP mode orbit and clock errors are not cancelled out which affects the quality of the tropospheric estimates. On the other hand it has the advantage that the GNSS observations are processed undifferenced. Latter is important because the Zero Difference Residuals (ZDR) contain the azimuthal-anisotropic part of the tropospheric delay which is not covered by the estimated parameters. From Double Difference Residuals (DDR) the ZDR can be recovered too but only conditionally since common tropospheric effects have been cancelled out in advance by differencing. In this presentation we show how good the anisotropic slant path delays can be obtained from GNSS observations processed using both concepts - the PPP and the DD approach. Therefore tropospheric zenith delays and N/E gradients were estimated and Pseudo-ZDR were reconstructed from DDR and afterwards compared with ZDR derived from the PPP solution. In addition it is shown how good both concepts are applicable for observations at very low elevation angles and under extreme weather conditions. The IGS final and ultra-rapid service products were taken into account to define the best strategy not only for post-processing but also for near real-time applications.

  11. Performance Analysis of Several GPS/Galileo Precise Point Positioning Models

    PubMed Central

    Afifi, Akram; El-Rabbany, Ahmed

    2015-01-01

    This paper examines the performance of several precise point positioning (PPP) models, which combine dual-frequency GPS/Galileo observations in the un-differenced and between-satellite single-difference (BSSD) modes. These include the traditional un-differenced model, the decoupled clock model, the semi-decoupled clock model, and the between-satellite single-difference model. We take advantage of the IGS-MGEX network products to correct for the satellite differential code biases and the orbital and satellite clock errors. Natural Resources Canada’s GPSPace PPP software is modified to handle the various GPS/Galileo PPP models. A total of six data sets of GPS and Galileo observations at six IGS stations are processed to examine the performance of the various PPP models. It is shown that the traditional un-differenced GPS/Galileo PPP model, the GPS decoupled clock model, and the semi-decoupled clock GPS/Galileo PPP model improve the convergence time by about 25% in comparison with the un-differenced GPS-only model. In addition, the semi-decoupled GPS/Galileo PPP model improves the solution precision by about 25% compared to the traditional un-differenced GPS/Galileo PPP model. Moreover, the BSSD GPS/Galileo PPP model improves the solution convergence time by about 50%, in comparison with the un-differenced GPS PPP model, regardless of the type of BSSD combination used. As well, the BSSD model improves the precision of the estimated parameters by about 50% and 25% when the loose and the tight combinations are used, respectively, in comparison with the un-differenced GPS-only model. Comparable results are obtained through the tight combination when either a GPS or a Galileo satellite is selected as a reference. PMID:26102495

  12. Performance Analysis of Several GPS/Galileo Precise Point Positioning Models.

    PubMed

    Afifi, Akram; El-Rabbany, Ahmed

    2015-01-01

    This paper examines the performance of several precise point positioning (PPP) models, which combine dual-frequency GPS/Galileo observations in the un-differenced and between-satellite single-difference (BSSD) modes. These include the traditional un-differenced model, the decoupled clock model, the semi-decoupled clock model, and the between-satellite single-difference model. We take advantage of the IGS-MGEX network products to correct for the satellite differential code biases and the orbital and satellite clock errors. Natural Resources Canada's GPSPace PPP software is modified to handle the various GPS/Galileo PPP models. A total of six data sets of GPS and Galileo observations at six IGS stations are processed to examine the performance of the various PPP models. It is shown that the traditional un-differenced GPS/Galileo PPP model, the GPS decoupled clock model, and the semi-decoupled clock GPS/Galileo PPP model improve the convergence time by about 25% in comparison with the un-differenced GPS-only model. In addition, the semi-decoupled GPS/Galileo PPP model improves the solution precision by about 25% compared to the traditional un-differenced GPS/Galileo PPP model. Moreover, the BSSD GPS/Galileo PPP model improves the solution convergence time by about 50%, in comparison with the un-differenced GPS PPP model, regardless of the type of BSSD combination used. As well, the BSSD model improves the precision of the estimated parameters by about 50% and 25% when the loose and the tight combinations are used, respectively, in comparison with the un-differenced GPS-only model. Comparable results are obtained through the tight combination when either a GPS or a Galileo satellite is selected as a reference. PMID:26102495

  13. Numerical modelling of river rearrangement along strike-slip faults

    NASA Astrophysics Data System (ADS)

    Brocard, G. Y.; Simon-Labric, T.; van der Beek, P.; Teyssier, C.

    2009-12-01

    Most studies of climate-tectonic interactions have focused on steady state orogens that evolve through orogen-normal convergence. Yet, most orogens have a major component of strike skip (wrenching). Although river captures occur in various kinds of geomorphic settings, they are frequently produced in such orogens by strike-slip faulting. The impacts of river captures are not well quantified because compelling diagnostic features and good quality proximal records are rarely found. We have modified the CASCADE numerical surface-process model to incorporate horizontal motion across a strike-slip fault and to study the evolution of drainage organization. Two river geometries are used to study the effect of horizontal movement on drainage systems. (1) The first simulates the deformation of an isolated crosswise stream. The continued horizontal displacement of streams leads to stream deflection and formation of a deep valley along the fault. The elongation of the river is not limited by the presence of other streams, and the lengthening process lowers river gradients and likely diminishes the river’s erosional efficiency. The ratio between uplift and strike-slip rates controls the response of drainage systems. We define two extreme cases (i) with a low ratio, the river presents a flat profile along the fault and a knick-point at a gorge outlet where the river leaves the fault; further work is in progress to test the influence of different parameters on the position of the knick-point; (ii) with a high ratio, catchment uplift compensates the horizontal elongation of the river. The river keeps the same profile. The system remains in steady-state. (2) The second geometry simulates two parallel crosswise rivers. In this case, lenghtening ends when drains are brought into contact by strike-slip faults. The physical barrier between them is tectonically removed. Our models show an expected transient increase in local relief and therefore basin incision. Through elongation and capture, deformation in a wrench zone produces a constantly evolving pattern of stream reaches with various incision rates. Drainage basins located upstream from the wrench zone experience a series of sudden captures and longer intervening periods of lengthening and slowing erosion. This results in oscillations in incision rate and internal drainage adjustments. Erosion and landscape, in these wrenched systems, thus operate in permanent disequilibrium.

  14. Characterization of positional errors and their influence on micro four-point probe measurements on a 100?nm Ru film

    NASA Astrophysics Data System (ADS)

    Kjaer, Daniel; Hansen, Ole; Westergaard sterberg, Frederik; Hartmann Henrichsen, Henrik; Markvardsen, Christian; Folmer Nielsen, Peter; Hjorth Petersen, Dirch

    2015-09-01

    Thin-film sheet resistance measurements at high spatial resolution and on small pads are important and can be realized with micrometer-scale four-point probes. As a result of the small scale the measurements are affected by electrode position errors. We have characterized the electrode position errors in measurements on Ru thin film using an Au-coated 12-point probe. We show that the standard deviation of the static electrode position error is on the order of 5?nm, which significantly affects the results of single configuration measurements. Position-error-corrected dual-configuration measurements, however, are shown to eliminate the effect of position errors to a level limited either by electrical measurement noise or dynamic position errors. We show that the probe contact points remain almost static on the surface during the measurements (measured on an atomic scale) with a standard deviation of the dynamic position errors of 3?. We demonstrate how to experimentally distinguish between different sources of measurement errors, e.g. electrical measurement noise, probe geometry error as well as static and dynamic electrode position errors.

  15. The Speech Focus Position Effect on Jaw-Finger Coordination in a Pointing Task

    ERIC Educational Resources Information Center

    Rochet-Capellan, Amelie; Laboissiere, Rafael; Galvan, Arturo; Schwartz, Jean-Luc

    2008-01-01

    Purpose: This article investigates jaw-finger coordination in a task involving pointing to a target while naming it with a 'CVCV (e.g., /'papa/) versus CV'CV (e.g., /pa'pa/) word. According to the authors' working hypothesis, the pointing apex (gesture extremum) would be synchronized with the apex of the jaw-opening gesture corresponding to the

  16. Modern Protection Against Lightning Strikes

    NASA Astrophysics Data System (ADS)

    Moore, C.

    2005-05-01

    The application of science to provide protection against lightning strikes began around 1750 when Benjamin Franklin who invented the lightning rod in an effort to discharge thunderclouds. Instead of preventing lightning as he expected, his rods have been quite successful as strike receptors, intercepting cloud-to ground discharges and conducting them to Earth without damage to the structures on which they are mounted. In the years since Franklin's invention there has been little attention paid to the rod configuration that best serves as a strike receptor but Franklin's original ideas continue to be rediscovered and promoted. Recent measurements of the responses of variously configured rods to nearby strikes indicate that sharp-tipped rods are not the optimum configuration to serve as strike receptors since the ionization of the air around their tips limits the strength of the local electric fields created by an approaching lightning leader. In these experiments, fourteen blunt-tipped rods exposed in strike-reception competitions with nearby sharp-tipped rods were struck by lightning but none of the sharp-tipped rods were struck.

  17. Stability characteristics of a supersonic boundary layer and their relation to the position of the laminar-turbulent transition point

    NASA Technical Reports Server (NTRS)

    Lysenko, V. I.

    1987-01-01

    By comparing the calculated results with experimental data, it is demonstrated that the position of the laminar-boundary transition point of a boundary layer can be estimated by using the e-exp-n method. The effect of the Mach number, pressure gradient, and heat transfer on the laminar-turbulent transition is discussed. It is found that under conditions of strong cooling, the effect of the pressure gradient on the position of the transition point is less pronounced than in the absence of heat transfer.

  18. Evaluation of Point Positioning Using the Global Positioning System and the Quasi-Zenith Satellite System as Measured from South Korea

    NASA Astrophysics Data System (ADS)

    Choi, Byung-Kyu; Cho, Chang-Hyun; Cho, Jung Ho

    2015-12-01

    The Quasi-Zenith Satellite System (QZSS), a dedicated regional Japanese satellite system currently under development, was designed to complement the performance of the Global Positioning System (GPS). The high elevation angle of the QZSS satellite is expected to enhance the effectiveness of GPS in urban environments. Thus, the work described in this paper, aimed to investigate the effect of QZSS on GPS performance, by processing the GPS and QZSS measurements recorded at the Bohyunsan reference station in South Korea. We used these data, to evaluate the satellite visibility, carrier-to-noise density (C/No), performance of single point positioning, and Dilution of Precision (DOP). The QZSS satellite is currently available over South Korea for 19 hours at an elevation angle of more than 10 degrees. The results showed that the impact of the QZSS on users' vertical positioning is greatest when the satellite is above 80 degrees of elevation. As for Precise Point Positioning (PPP) performance, the combined GPS/QZSS kinematic PPP was found to improve the positioning accuracy compared to the GPS only kinematic PPP.

  19. Positive Thinking & Good Citizenship Culture: From the Jordanian Universities Students' Points of View

    ERIC Educational Resources Information Center

    Jarrar, Amani Ghazi

    2013-01-01

    This study aims at identifying the nature of the relationship between the mode of thinking among the students of Jordanian Universities if positive, and the extent to which that is related to their culture of citizenship, and therefore their positive practices towards the community. A sample of (654) students were selected randomly. And to achieve

  20. Lightning strike protection of composites

    NASA Astrophysics Data System (ADS)

    Gagn, Martin; Therriault, Daniel

    2014-01-01

    Aircraft structures are being redesigned to use fiber-reinforced composites mainly due to their high specific stiffness and strength. One of the main drawbacks from changing from electrically conductive metals to insulating or semi-conducting composites is the higher vulnerability of the aircraft to lightning strike damage. The current protection approach consists of bonding a metal mesh to the surface of the composite structure, but this weight increase negatively impact the fuel efficiency. This review paper presents an overview of the lightning strike problematic, the regulations, the lightning damage to composite, the current protection solutions and other material or technology alternatives. Advanced materials such as polymer-based nanocomposites and carbon nanotube buckypapers are promising candidates for lightweight lightning strike protection technology.

  1. Precise angular position measurement of a point source in an optoelectronic system with CCD arrays upon a single readout

    NASA Astrophysics Data System (ADS)

    Lebedko, Evgeny G.; Zvereva, Elena N.

    2015-05-01

    The purpose of this article is to examine the method of angular position measuring of a point source in a system with a CCD array by means of linear dimension - time slot - code transformation and assessment of the potential accuracy of the method, which is determined by instrumental irremovable random errors of measurement in terms of optimal processing of incoming information with a single reading it with CCD - lines. This work introduces an optoelectronic system circuit with CCD arrays with stretched sensing elements and a point of reference for angular position measuring. In this case the arrays have images projections of both the reference point source and the target point source, whose angular position is measured with high precision. From the CCD array output the signals arrive at an optimal (or apt) linear filter, and then to the signal peak position detection circuit, which provides the minimum error due to noise impact. Pulse edges, corresponding to the signals maximum, make a time interval filled with high-frequency counting pulses. The number of pulses in this interval will correspond to the measured angular position of the target point source. In terms of the statistical decision theory this work analyses random errors given the signals spectral function that, in turn, accounts for the transfer function of the optical system and the CCD array as an image analyzer. This article also presents analysis of how measurement accuracy depends on frequency of information readout from the CCD-arrays for different values of signal-to-noise ratio. Error analysis of the proposed optoelectronic circuits showed that measurements can be made upon a single readout with an accuracy of 0.01 and even 0,001 pixels.

  2. [Neurological symptoms following lightening strike].

    PubMed

    van Spijker, Rianne C; Monasch, Ed; Compier-Mahboob, Noor; Merkies, Ingemar S J

    2009-01-01

    A 56-year-old man was referred to the neurological outpatients' department suffering from problems with walking and painful, burning feet after having been struck by lightning 6 months previously. He also experienced orthostatic symptoms and episodes of 'flushing' and was unable to tolerate contact with clothing or bed sheets on his lower legs or feet. After excluding other possible causes, the patient was diagnosed with 'polyneuropathy due to lightning strike'. Gabapentine had a favourable effect on the sensory symptoms. Lightening strikes are a rare cause of polyneuropathy. PMID:20047699

  3. Eyeing New York's Newspaper Strike.

    ERIC Educational Resources Information Center

    Fishleder, Paul

    The New York newspaper strike of 1978 was the direct result of a series of events that started in 1923 when the pressmen's union established a system that provided a minimum fixed number of pressmen per press unit and legitimized a loose labor pool. From that time, the number of pressmen increased through family-dominated union management that

  4. Soviet KIROV class strike cruiser

    SciTech Connect

    Kehoe, J.W.; Brower, K.S.; Meier, H.A.

    1981-04-01

    The major design concepts and basic characteristics of the Soviet KIROV Class ship, an impressive nuclear-powered Strike Cruiser which recently appeared while undergoing sea trials in the Baltic Sea and the North Sea, are discussed. Highlights are presented of the KIROV's hull form, the weapons, electronics and aviation systems, machinery, as well as the cruiser's speed and range.

  5. EMAS position statement: The ten point guide to the integral management of menopausal health.

    PubMed

    Neves-E-Castro, Manuel; Birkhauser, Martin; Samsioe, Goran; Lambrinoudaki, Irene; Palacios, Santiago; Borrego, Rafael Sanchez; Llaneza, Placido; Ceausu, Iuliana; Depypere, Herman; Erel, C Tamer; Prez-Lpez, Faustino R; Schenck-Gustafsson, Karin; van der Schouw, Yvonne T; Simoncini, Tommaso; Tremollieres, Florence; Rees, Margaret

    2015-05-01

    With increased longevity and more women becoming centenarians, management of the menopause and postreproductive health is of growing importance as it has the potential to help promote health over several decades. Women have individual needs and the approach needs to be personalised. The position statement provides a short integral guide for all those involved in menopausal health. It covers diagnosis, screening for diseases in later life, treatment and follow-up. PMID:25757366

  6. Positional accuracy in RPC point determination based on high-resolution imagery

    NASA Astrophysics Data System (ADS)

    Meng, Han; Liu, Yongliang; Zhang, Jingxiong; Gong, Hao

    2007-06-01

    The rational function model (RFM), also known as rational polynomial coefficients (RPCs) or rational polynomial camera (RPC) model, is a generalized sensor model. Different from rigorous sensor model, RFM does not need to obtain the interior and exterior orientation geometry and other physical properties associated with the physical sensor. RFMs were first adopted by Space Imaging company as a replacement for rigorous sensor models, and it drew much attention from the commercial satellite data vendors who rapidly followed the suit in order to protect the confidential information of the sensors. This paper focuses on the solution for rational polynomial coefficients, RFM-based stereo-model reconstitution, and positional accuracy analysis. As RPCs do not have obvious physical meanings and their solution is iterative, analytical approaches to accuracy analysis may not be feasible; computer simulation is thus adopted to quantify accuracy in RPC-determined positional data. The simulation-based strategy is efficient in mapping local features in positional errors, which contain both the systematic and random components.

  7. Influence of meteorological data and horizontal gradient of tropospheric model on precise point positioning

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Jiang, Nan; Xu, Guochang; Yang, Yuanxi; Schuh, Harald

    2015-12-01

    Using GPT2 derived meteorological data and actual meteorological observations can achieve the same positioning precision in the most areas worldwide except for the Antarctic region. However, the improvement of the actual meteorological observations on the positioning result is significant comparing to using GPT2 derived meteorological data in Antarctic. In the case of 5° elevation cut-off angle, the height precision can be improved by 25%. Furthermore, when the elevation cut-off angle is lower, the effect of the actual meteorological observations on the positioning precision is more significant in Antarctic due to the retention of low elevation angle observations. This study also shows that the influence of tropospheric horizontal gradient correction can improve the PPP precision. Under the lower elevation cut-off angle and higher humidity conditions, especially in summer time and low-latitudes area, the usefulness of the horizontal gradient correction is remarkable. The average improvement of N, E and U directions can reach up to 51%, 15% and 30%, respectively.

  8. A Method to Improve the Temperature Distribution of Holder Around the Fixed-Point Cell Position

    NASA Astrophysics Data System (ADS)

    Lim, S. D.; Karmalawi, A. M.; Salim, S. G. R.; Soliman, M. A.; Kim, B. H.; Lee, D. H.; Yoo, Y. S.

    2014-07-01

    The temperature profile along the furnaces used in heating high-temperature fixed points has a crucial impact on the quality and duration of melting plateaux, accordingly the accuracy of thermodynamic temperature determination of such fixed points. This paper describes a simple, yet efficient, approach for improving the temperature uniformity along a cell holder in high-temperature blackbody (HTBB) furnaces that use pyrolytic graphite rings as heating elements. The method has been applied on the KRISS' HTBB furnace. In this work, an ideal solution for arranging the heating elements inside the furnace is presented by which the temperature gradient across the cell holder can be kept as low as possible. Numerical calculations, based on a finite element method, have been carried out to find the best possible arrangement of the rings. This has been followed by measuring the temperature gradient along an empty cell holder to validate our calculations. A temperature gradient of 100 mK has been achieved at over a length of 50 mm within a cell holder of 10 cm in length. It has also been shown that for a 20 cm long holder surrounded by rings with an arbitrary resistance profile, the temperature uniformity can be improved by adding a few "hot" rings around the cell holder.

  9. Spatiotemporal Integration in Somatosensory Perception: Effects of Sensory Saltation on Pointing at Perceived Positions on the Body Surface

    PubMed Central

    Trojan, Jrg; Stolle, Annette M.; Carl, Antonija Mri?; Kleinbhl, Dieter; Tan, Hong Z.; Hlzl, Rupert

    2010-01-01

    In the past, sensory saltation phenomena (Geldard and Sherrick, 1972) have been used repeatedly to analyze the spatiotemporal integration capacity of somatosensory and other sensory mechanisms by means of their psychophysical characteristic. The core phenomenon consists in a systematic mislocalization of one tactile stimulus (the attractee) toward another successive tactile stimulus (the attractant) presented at another location, increasing with shorter intervals. In a series of four experiments, sensory saltation characteristics were studied at the forearm and the abdomen. Participants reported the perceived positions of attractees, attractants, and reference stimuli by pointing. In general, saltation characteristics compared well to those reported in previous studies, but we were able to gain several new insights regarding this phenomenon: (a) the attracteeattractant interval did not exclusively affect the perceived attractee position, but also the perceived attractant position; (b) saltation characteristics were very similar at different body sites and orientations, but did show differences suggesting anisotropy (direction-dependency) in the underlying integration processes; (c) sensory saltation could be elicited with stimulation patterns crossing the body midline on the abdomen. In addition to the saltation-specific results, our experiments demonstrate that pointing reports of perceived positions on the body surface generally show pronounced systematic biases compared to veridical positions, moderate intraindividual consistency, and a high degree of inter-individual variability. Finally, we address methodological and terminological controversies concerning the sensory saltation paradigm and discuss its possible neurophysiological basis. PMID:21833262

  10. Relativistic dynamics of interacting point particles: Central position of the Wheeler-Feynman scheme

    NASA Astrophysics Data System (ADS)

    Costa de Beauregard, O.

    1985-06-01

    The Wheeler-Feynman (WF) relativistic theory of interacting point particles, generalized by acceptance of an arbitrary spacelike interaction, is shown to possess a privileged status, reminiscent of the central force interactions occurring in Newtonian mechanics. This scheme is shown to be isomorphic to the classical one of the statics of interacting flexible current-carrying wires obeying the Ampre-Laplace (AL) formulas: to the tension T (T 2 =const) of the wire corresponds the momentum-energy pi (pipi=-c2m2) of the particle; to the Laplace linear force density -i Hdr corresponds the Lorentz force QHij drj; to the Laplace potential ir-1 dr corresponds the WF potential Q?(r2) dri, etc. Among the differences, there is self-action in the AL scheme and no self-action in the WF scheme. A stationary energy principle in the AL scheme is isomorphic to Fokker's stationary action principle in the WF scheme.

  11. Crustal deformation measurements in central Japan determined by a Global Positioning System fixed-point network

    NASA Technical Reports Server (NTRS)

    Shimada, Seiichi; Bock, Yehuda

    1992-01-01

    Results are presented from temporally dense measurements of crustal deformation associated with the convergence of the Eurasian (EUR), Pacific, North American, and Philippine Sea (PHS) plates, carried out in April 1988 by a 10-station GPS fixed-point network established in central Japan. Using regional orbit relaxation methods, the analysis of the first 17-month data revealed significant horizontal deformation across the Suruga trough. Namely, it was found that a site in the northern tip of PHS plate moved nearly westward with a velocity of 28 +/-5 mm per year, and a site at the southeastern tip of EUR plate moved south-southwestward with a velocity of 18 +/-5 mm per year. A significant vertical uplift with a velocity of 20 mm/yr was detected at a site inland of the Tokai district located in the Akaishi uplift zone and at a site on the Hatsushima Island in Sagami Bay.

  12. Bounded components of positive solutions of abstract fixed point equations: mushrooms, loops and isolas

    NASA Astrophysics Data System (ADS)

    Lpez-Gmez, Julin; Molina-Meyer, Marcela

    In this work a general class of nonlinear abstract equations satisfying a generalized strong maximum principle is considered in order to study the behavior of the bounded components of positive solutions bifurcating from the curve of trivial states (?,u)=(?,0) at a nonlinear eigenvalue ?=?0 with geometric multiplicity one. Since the unilateral theorems of Rabinowitz (J. Funct. Anal. 7 (1971) 487, Theorems 1.27 and 1.40) are not true as originally stated (cf. the very recent counterexample of Dancer, Bull. London Math. Soc. 34 (2002) 533), in order to get our main results the unilateral theorem of Lpez-Gmez (Spectral Theory and Nonlinear Functional Analysis, Research Notes in Mathematics, vol. 426, CRC Press, Boca Raton, FL, 2001, Theorem 6.4.3) is required. Our analysis fills some serious gaps existing is some published papers that were provoked by a direct use of Rabinowitz's unilateral theory. Actually, the abstract theory developed in this paper cannot be covered with the pioneering results of Rabinowitz (1971), since in Rabinowitz's context any component of positive solutions must be unbounded, by a celebrated result attributable to Dancer (Arch. Rational Mech. Anal. 52 (1973) 181).

  13. Real-Time Point Positioning Performance Evaluation of Single-Frequency Receivers Using NASA's Global Differential GPS System

    NASA Technical Reports Server (NTRS)

    Muellerschoen, Ronald J.; Iijima, Byron; Meyer, Robert; Bar-Sever, Yoaz; Accad, Elie

    2004-01-01

    This paper evaluates the performance of a single-frequency receiver using the 1-Hz differential corrections as provided by NASA's global differential GPS system. While the dual-frequency user has the ability to eliminate the ionosphere error by taking a linear combination of observables, the single-frequency user must remove or calibrate this error by other means. To remove the ionosphere error we take advantage of the fact that the magnitude of the group delay in range observable and the carrier phase advance have the same magnitude but are opposite in sign. A way to calibrate this error is to use a real-time database of grid points computed by JPL's RTI (Real-Time Ionosphere) software. In both cases we evaluate the positional accuracy of a kinematic carrier phase based point positioning method on a global extent.

  14. Wavelet Transform Analysis of Electromyography Kung Fu Strikes Data

    PubMed Central

    Neto, Osmar Pinto; Marzullo, Ana Carolina de Miranda

    2009-01-01

    In martial arts and contact sports strikes are performed at near maximum speeds. For that reason, electromyography (EMG) analysis of such movements is non-trivial. This paper has three main goals: firstly, to investigate the differences in the EMG activity of muscles during strikes performed with and without impacts; secondly, to assess the advantages of using Sum of Significant Power (SSP) values instead of root mean square (rms) values when analyzing EMG data; and lastly to introduce a new method of calculating median frequency values using wavelet transforms (WMDF). EMG data of the deltoid anterior (DA), triceps brachii (TB) and brachioradialis (BR) muscles were collected from eight Kung Fu practitioners during strikes performed with and without impacts. SSP results indicated significant higher muscle activity (p = 0.023) for the strikes with impact. WMDF results, on the other hand, indicated significant lower values (p = 0. 007) for the strikes with impact. SSP results presented higher sensitivity than rms to quantify important signal differences and, at the same time, presented lower inter-subject coefficient of variations. The result of increase in SSP values and decrease in WMDF may suggest better synchronization of motor units for the strikes with impact performed by the experienced Kung Fu practitioners. Key Points The results show higher muscle activity and lower electromyography median frequencies for strikes with impact compared to strikes without. SSP results presented higher sensitivity and lower inter-subject coefficient of variations than rms results. Kung Fu palm strikes with impact may present better motor units synchronization than strikes without. PMID:24474883

  15. Non-Linear Filtering for Precise Point Positioning GPS/INS integration

    NASA Astrophysics Data System (ADS)

    Abd Rabbou, M.; El-Rabbany, A.

    2014-11-01

    This research investigates the performance of non-linear estimation filtering for GPS-PPP/MEMS-based inertial system. Although integrated GPS/INS system involves nonlinear motion state and measurement models, the most common estimation filter employed is extended Kalman filter. In this paper, both unscented Kalman filter and particle filter are developed and compared with extended Kalman filter. Tightly coupled mechanization is adopted, which is developed in the raw measurements domain. Un-differenced ionosphere-free linear combination of pseudorange and carrier-phase measurements is employed. The performance of the proposed non-linear filters is analyzed using real test scenario. The test results indicate that comparable accuracy-level are obtained from the proposed filters compared with extended Kalman filter in positioning, velocity and attitude when the measurement updates from GPS measurements are available.

  16. Trapezius upper portion trigger points treatment purpose in positional release therapy with electromyographic analysis

    PubMed Central

    Kelencz, Carlos Alberto; Tarini, Victor Alexandre F.; Amorim, Cesar Ferreira

    2011-01-01

    Background: This quantification process is made through electromyography analysis. This technique of analysis is able to provide a general view of the tension decrease in the superior muscle fibers of the trapezius after therapy. Aims: The focus of the present work is to evaluate the treatment of the cervicobrachialgia by Positional Release Therapy (PRT). Material and Methods: The present work studies six patients, with ages 44 to 63 (1 male and 5 female) who present tension in the trapezius upper portion fibers. All patients were submitted to 10 session of 30 minutes each. The electromyography was collected on the first and tenth day of treatment. Results: The results demonstrated a progressive decrease of pain in each session. The tension was evaluated by the electromyography analysis, which showed the relations between time of treatment and less pain. Conclusion: With these results, it was possible to verify quantitatively the efficiency of the PRT in the improvement of life quality. PMID:22363082

  17. Three point lead screw positioning apparatus for a cavity tuning plate

    NASA Technical Reports Server (NTRS)

    Calco, Frank S. (inventor)

    1993-01-01

    Three lead screws are provided for adjusting the position of a traversing plate. Each of the three lead screws is threaded through a collar that is press fitted through the center of one of three pinion gears. A sun gear meshes with all three pinion gears and transversely moves the three lead screws upon actuation of a drive gear. The drive gear meshes with the sun gear and is driven by a handle or servomotor. When the handle or servomotor rotates the drive gear, the sun gear rotates causing the three pinion gears to rotate, thus, causing transverse movement of the three lead screws and, accordingly, transverse movement of the transversing plate. When the drive gear rotates, the traversing plate is driven in and out of a microwave cavity. Thus, the length or size of the cavity can be tuned while maintaining the traversing plate in an exact parallel relationship with an opposing plate on another end of the cavity.

  18. A new approach to the determination of the striking distance from the lightning channel photos

    NASA Technical Reports Server (NTRS)

    Vorgucic, A.; Mladenovic, I.

    1991-01-01

    The possible influence the stepped leader movement has on the value of the striking distance is studied. The numerical values of the striking distances are most frequently verified from the lightning channel photos. There is some explanations for dispersion of the striking distance which usually appear on tall structures. Unusually long striking distance may be influenced by the positive space charge or prior upward flashes. One more parameter which may have influence in estimation of the striking distance is a complex charge motion in the leader channel. Through introduction of two types of charge motions, possible shortening is shown of the striking distance seen on the lightning channel photos.

  19. [Force-feeding of hunger-striking prisoners].

    PubMed

    Glick, Shimon

    2014-09-01

    In contrast to the position of the World Medical Association and the Ethics Council of the Israel Medical Association, the author argues for forced-feeding of hunger-striking prisoners when their condition reaches a stage of danger of death or permanent injury. This position is based on the priority of human life over autonomy, and of a communitarian ethic. This position is supported by a District Court decision ordering the feeding of a hunger-striking prisoner, by a Supreme Court decision imposing surgery on a non-consenting prisoner, and in line with Israel's Patient's Right Law. PMID:25417495

  20. Position difference regularity of corresponding R-wave peaks for maternal ECG components from different abdominal points

    NASA Astrophysics Data System (ADS)

    Zhang, Jie-Min; Guan, Qun; Tang, Li-Ming; Liu, Tie-Bing; Liu, Hong-Xing; Huang, Xiao-Lin; Si, Jun-Feng

    2014-01-01

    We collected 343 groups of abdominal electrocardiogram (ECG) data from 78 pregnant women and deleted the channels unable for experts to determine R-wave peaks from them; then, based on these filtered data, the statistics of position difference of corresponding R-wave peaks for different maternal ECG components from different points were studied. The resultant statistics showed the regularity that the position difference of corresponding maternal R-wave peaks between different abdominal points does not exceed the range of 30 ms. The regularity was also proved using the fECG data from MITBIH PhysioBank. Additionally, the paper applied the obtained regularity, the range of position differences of the corresponding maternal R-wave peaks, to accomplish the automatic detection of maternal R-wave peaks in the recorded all initial 343 groups of abdominal signals, including the ones with the largest fetal ECG components, and all 55 groups of ECG data from MITBIH PhysioBank, achieving the successful separation of the maternal ECGs.

  1. Joint positioning sense, perceived force level and two-point discrimination tests of young and active elderly adults

    PubMed Central

    Franco, Priscila G.; Santos, Karini B.; Rodacki, Andr L. F.

    2015-01-01

    Background: Changes in the proprioceptive system are associated with aging. Proprioception is important to maintaining and/or recovering balance and to reducing the risk of falls. Objective: To compare the performance of young and active elderly adults in three proprioceptive tests. Method: Twenty-one active elderly participants (66.95.5 years) and 21 healthy young participants (24.63.9 years) were evaluated in the following tests: perception of position of the ankle and hip joints, perceived force level of the ankle joint, and two-point discrimination of the sole of the foot. Results: No differences (p>0.05) were found between groups for the joint position and perceived force level. On the other hand, the elderly participants showed lower sensitivity in the two-point discrimination (higher threshold) when compared to the young participants (p < 0.01). Conclusion: Except for the cutaneous plantar sensitivity, the active elderly participants had maintained proprioception. Their physical activity status may explain similarities between groups for the joint position sense and perceived force level, however it may not be sufficient to prevent sensory degeneration with aging. PMID:26443978

  2. The influence of entry point and radius of curvature on femoral intramedullary nail position in the distal femur

    PubMed Central

    Kanawati, Andrew J.; Jang, Bob; McGee, Richard; Sungaran, Jai

    2014-01-01

    Aim Perforation of the anterior cortex during femoral intramedullary nailing can be a major complication. We aim to determine the influence of entry point and radius of curvature on intramedullary nail position in the distal femur using a synthetic bone model. Methods Using synthetic femora, the greater trochanter was measured and entry points marked in two planes. A standard recommended technique was used to insert two different Stryker Gamma 3 intramedullary nails of different radius of curvature. The synthetic femora were sectioned and the centre of nail to anterior cortex distance (CAD) was measured. Statistical interpretation of the results was performed using linear regression analyses. Results We found that the more posterior entry points led to a more anterior placement in the distal femur in both nails of differing radius of curvature (11mm and 13.5mm CAD). The smaller radius of curvature led to a more central placement of the nail tip in the distal femur. Conclusion Anterior penetration of the distal femur can be minimized by a more anterior entry point and with the use of a femoral intramedullary nail with a smaller radius of curvature. PMID:25104888

  3. Lightning strike at Bryan, Ohio

    SciTech Connect

    Nichols, B. E.

    1980-02-01

    A week before the 29 August 1979 dedication of the photovoltaic power system at daytime AM radio station WBNO, in Bryan, Ohio, a lightning superbolt struck the FM radio tower, one of two towers at the station. Minor damage to the station and to components of the photovoltaic system, the latter designed by MIT Lincoln Laboratory under US Department of Energy sponsorship, is described. This rare strike suggested the need for increased protection and more voltage-transient suppressors were added to those already in place as a preventive measure in the event that such a phenomenon reoccurs.

  4. On the convergence of ionospheric constrained precise point positioning (IC-PPP) based on undifferential uncombined raw GNSS observations.

    PubMed

    Zhang, Hongping; Gao, Zhouzheng; Ge, Maorong; Niu, Xiaoji; Huang, Ling; Tu, Rui; Li, Xingxing

    2013-01-01

    Precise Point Positioning (PPP) has become a very hot topic in GNSS research and applications. However, it usually takes about several tens of minutes in order to obtain positions with better than 10 cm accuracy. This prevents PPP from being widely used in real-time kinematic positioning services, therefore, a large effort has been made to tackle the convergence problem. One of the recent approaches is the ionospheric delay constrained precise point positioning (IC-PPP) that uses the spatial and temporal characteristics of ionospheric delays and also delays from an a priori model. In this paper, the impact of the quality of ionospheric models on the convergence of IC-PPP is evaluated using the IGS global ionospheric map (GIM) updated every two hours and a regional satellite-specific correction model. Furthermore, the effect of the receiver differential code bias (DCB) is investigated by comparing the convergence time for IC-PPP with and without estimation of the DCB parameter. From the result of processing a large amount of data, on the one hand, the quality of the a priori ionosphere delays plays a very important role in IC-PPP convergence. Generally, regional dense GNSS networks can provide more precise ionosphere delays than GIM and can consequently reduce the convergence time. On the other hand, ignoring the receiver DCB may considerably extend its convergence, and the larger the DCB, the longer the convergence time. Estimating receiver DCB in IC-PPP is a proper way to overcome this problem. Therefore, current IC-PPP should be enhanced by estimating receiver DCB and employing regional satellite-specific ionospheric correction models in order to speed up its convergence for more practical applications. PMID:24253190

  5. On the Convergence of Ionospheric Constrained Precise Point Positioning (IC-PPP) Based on Undifferential Uncombined Raw GNSS Observations

    PubMed Central

    Zhang, Hongping; Gao, Zhouzheng; Ge, Maorong; Niu, Xiaoji; Huang, Ling; Tu, Rui; Li, Xingxing

    2013-01-01

    Precise Point Positioning (PPP) has become a very hot topic in GNSS research and applications. However, it usually takes about several tens of minutes in order to obtain positions with better than 10 cm accuracy. This prevents PPP from being widely used in real-time kinematic positioning services, therefore, a large effort has been made to tackle the convergence problem. One of the recent approaches is the ionospheric delay constrained precise point positioning (IC-PPP) that uses the spatial and temporal characteristics of ionospheric delays and also delays from an a priori model. In this paper, the impact of the quality of ionospheric models on the convergence of IC-PPP is evaluated using the IGS global ionospheric map (GIM) updated every two hours and a regional satellite-specific correction model. Furthermore, the effect of the receiver differential code bias (DCB) is investigated by comparing the convergence time for IC-PPP with and without estimation of the DCB parameter. From the result of processing a large amount of data, on the one hand, the quality of the a priori ionosphere delays plays a very important role in IC-PPP convergence. Generally, regional dense GNSS networks can provide more precise ionosphere delays than GIM and can consequently reduce the convergence time. On the other hand, ignoring the receiver DCB may considerably extend its convergence, and the larger the DCB, the longer the convergence time. Estimating receiver DCB in IC-PPP is a proper way to overcome this problem. Therefore, current IC-PPP should be enhanced by estimating receiver DCB and employing regional satellite-specific ionospheric correction models in order to speed up its convergence for more practical applications. PMID:24253190

  6. NASA storm hazards research in lightning strikes to aircraft

    NASA Technical Reports Server (NTRS)

    Fisher, B. D.; Brown, P. W.; Plumer, J. A.

    1985-01-01

    The lightning strike condition data gathered in the 1980-1984 period are presented, together with the lightning attachment point analysis for the NASA F-106B research aircraft are presented. The analysis of the experienced 637 direct lightning strikes shows that the highest strike rates (2.1 strikes/min and 13 strikes/penetration) occurred at altitudes between 38,000 and 40,000 ft. The regions of highest risk for an aircraft to experience a direct lightning strike were the areas of thunderstorms where the ambient temperature was colder than -40 C and where the relative turbulence and precipitation intensities were characterized as negligible to light. The presence and location of lightning, therefore, did not necessarily indicate the presence and location of hazardous precipitation and turbulence. The total onboard data show that the lightning attachment patterns on this aircraft fall into four general categories, although the 1984 data suggest that the entire surface of the F-106B may be susceptible to lightning attachment.

  7. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  8. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  9. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  10. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  11. 14 CFR 35.38 - Lightning strike.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Lightning strike. 35.38 Section 35.38... STANDARDS: PROPELLERS Tests and Inspections § 35.38 Lightning strike. The applicant must demonstrate, by... lightning strike without causing a major or hazardous propeller effect. The limit to which the propeller...

  12. Contingency Planning for Teacher Strikes. ERS Report.

    ERIC Educational Resources Information Center

    Kunder, Linda H.

    The purpose of this report is to help school administrators develop their own strike contingency plans or evaluate the plans already in existence in their districts. The report comprises four sections: (1) a review of the educational literature regarding strike contingency planning; (2) state board guidelines for strike contingency planning; (3)

  13. Precise point positioning performance in the presence of the 28 October 2003 sudden increase in total electron content

    NASA Astrophysics Data System (ADS)

    Rodrguez-Bilbao, I.; Radicella, S. M.; Rodrguez-Caderot, G.; Herraiz, M.

    2015-10-01

    Intense disturbances in the ionosphere may produce perturbations in Global Navigation Satellite Systems (GNSS) radio signals that in the most severe cases produce receiver tracking problems, which in turn impact on GNSS positioning accuracy. In this paper we present a case study related to the sudden increase in total electron content (SITEC) induced by the X17.2 solar flare that occurred on 28 October 2003. This is the largest SITEC ever recorded by means of the rate of change of total electron content. A solar radio burst (SRB) occurred in the same period which caused GNSS signal fading and in some cases complete signal loss. Although SITEC contribution to the signal noise cannot be separated from that of SRB, in this paper we show that accuracy degradation may happen in kinematic precise point positioning (PPP) in several stations of the sunlit hemisphere when 30 s sampling rate data are analyzed. The observed errors in the position are the result of the difficulties that cycle slip (CS) detection strategies have to deal with the observables that have been affected by the SITEC.

  14. Three dimensional indoor positioning based on visible light with Gaussian mixture sigma-point particle filter technique

    NASA Astrophysics Data System (ADS)

    Gu, Wenjun; Zhang, Weizhi; Wang, Jin; Amini Kashani, M. R.; Kavehrad, Mohsen

    2015-01-01

    Over the past decade, location based services (LBS) have found their wide applications in indoor environments, such as large shopping malls, hospitals, warehouses, airports, etc. Current technologies provide wide choices of available solutions, which include Radio-frequency identification (RFID), Ultra wideband (UWB), wireless local area network (WLAN) and Bluetooth. With the rapid development of light-emitting-diodes (LED) technology, visible light communications (VLC) also bring a practical approach to LBS. As visible light has a better immunity against multipath effect than radio waves, higher positioning accuracy is achieved. LEDs are utilized both for illumination and positioning purpose to realize relatively lower infrastructure cost. In this paper, an indoor positioning system using VLC is proposed, with LEDs as transmitters and photo diodes as receivers. The algorithm for estimation is based on received-signalstrength (RSS) information collected from photo diodes and trilateration technique. By appropriately making use of the characteristics of receiver movements and the property of trilateration, estimation on three-dimensional (3-D) coordinates is attained. Filtering technique is applied to enable tracking capability of the algorithm, and a higher accuracy is reached compare to raw estimates. Gaussian mixture Sigma-point particle filter (GM-SPPF) is proposed for this 3-D system, which introduces the notion of Gaussian Mixture Model (GMM). The number of particles in the filter is reduced by approximating the probability distribution with Gaussian components.

  15. Centroid Position as a Function of Total Counts in a Windowed CMOS Image of a Point Source

    SciTech Connect

    Wurtz, R E; Olivier, S; Riot, V; Hanold, B J; Figer, D F

    2010-05-27

    We obtained 960,200 22-by-22-pixel windowed images of a pinhole spot using the Teledyne H2RG CMOS detector with un-cooled SIDECAR readout. We performed an analysis to determine the precision we might expect in the position error signals to a telescope's guider system. We find that, under non-optimized operating conditions, the error in the computed centroid is strongly dependent on the total counts in the point image only below a certain threshold, approximately 50,000 photo-electrons. The LSST guider camera specification currently requires a 0.04 arcsecond error at 10 Hertz. Given the performance measured here, this specification can be delivered with a single star at 14th to 18th magnitude, depending on the passband.

  16. Estimation of precipitable water vapour using kinematic GNSS precise point positioning over an altitude range of 1 km

    NASA Astrophysics Data System (ADS)

    Webb, S. R.; Penna, N. T.; Clarke, P. J.; Webster, S.; Martin, I.

    2013-12-01

    The estimation of total precipitable water vapour (PWV) using kinematic GNSS has been investigated since around 2001, aiming to extend the use of static ground-based GNSS, from which PWV estimates are now operationally assimilated into numerical weather prediction models. To date, kinematic GNSS PWV studies suggest a PWV measurement agreement with radiosondes of 2-3 mm, almost commensurate with static GNSS measurement accuracy, but only shipborne experiments have so far been carried out. As a first step towards extending such sea level-based studies to platforms that operate at a range of altitudes, such as airplanes or land based vehicles, the kinematic GNSS estimation of PWV over an exactly repeated trajectory is considered. A data set was collected from a GNSS receiver and antenna mounted on a carriage of the Snowdon Mountain Railway, UK, which continually ascends and descends through 950 m of vertical relief. Static GNSS reference receivers were installed at the top and bottom of the altitude profile, and derived zenith wet delay (ZWD) was interpolated to the altitude of the train to provide reference values together with profile estimates from the 100 m resolution runs of the Met Office's Unified Model. We demonstrate similar GNSS accuracies as obtained from previous shipborne studies, namely a double difference relative kinematic GNSS ZWD accuracy within 14 mm, and a kinematic GNSS precise point positioning ZWD accuracy within 15 mm. The latter is a more typical airborne PWV estimation scenario i.e. without the reliance on ground-based GNSS reference stations. We show that the kinematic GPS-only precise point positioning ZWD estimation is enhanced by also incorporating GLONASS observations.

  17. Trojan wavepackets bound on Lagrange equllibrium points of two positive ions binary system in the strong magnetic field

    NASA Astrophysics Data System (ADS)

    Kalinski, Matt

    2012-06-01

    We once have shown that the combination of the Circularly Polarized Electromagnetic (CP) wave field and the central Coulomb proton field is capable to keep the hydrogen atom in the complex space-correlated coherent state of the electron in the rotating frame eliminating the principal time dependence [1]. This state corresponds to the stable and nondispersing electron wave packet moving around the circle in the laboratory frame. Here we show the existence of stable nondispersing single and two-electron wavepackets localized around Langrange equilibrium points of two positive ions in binary star configuration executing cyclotron motion around each other in strong eternal magnetic field. Unlike for the normal Trojan wavepackets they do not require external CP field to localize and correspond exactly to atom size scaled Trojan asteroids in the Sun-Jupiter system. The exact numerical simulations using Split Operator Fast Fourier Transform method are also provided for the single electron while the approximate time-dependent Hartree simulations for two electrons. [4pt] [1] I. Bialynicki-Birula, M. Kalinski, and J.H Eberly,``Lagrange Equilibrium Points in Celestial Mechanics and Nonspreading Wave Packets for Strongly Driven Rydberg Electrons,'' Phys. Rev. 73, 1777 (1994).

  18. Impact of mapping functions based on spherical, ellipsoidal, gradient, and 3d atmospheric structures on GPS Precise Point Positioning

    NASA Astrophysics Data System (ADS)

    Nievinski, F. G.; Santos, M. C.

    2008-12-01

    We evaluate the impact of mapping functions developed from different atmospheric structures on precise point positioning. In each case the atmospheric structure is derived from the same Numerical Weather Model (NWM). We compared five different structures -- from simpler to more realistic: spherical concentric, spherical osculating, ellipsoidal, gradient, and 3D -- and a state-of-art mapping function, Vienna Mapping Functions Site (VMF1). We used data from IGS station ALGO. Results correspond to comparisons with the IGS (non- cumulative) weekly solution. The spherical concentric model shows a large (cm-level) bias in the north component. The spherical osculating (and ellipsoidal) model shows an improvement in the up component, by almost one order of magnitude, over that of VMF1. The 3D atmosphere model reduces the horizontal bias to less than 1 mm, but there is no apparent improvement in the vertical position, which we attribute to unaccounted non-tidal atmospheric pressure loading. Finally, the gradient atmosphere shows biases with magnitude in between those of the spherical osculating and 3d models.

  19. Ambiguity-fixed GPS precise point positioning for earthquake and tsunami early warning in Western North America

    NASA Astrophysics Data System (ADS)

    Geng, J.; Bock, Y.; Fang, P.; Haase, J. S.

    2012-12-01

    The development of single-receiver integer ambiguity resolution in recent years has made the GPS precise point positioning (PPP) technique a valuable tool in measuring centimeter-level displacements epoch by epoch at a single station. A good application for this technique is identifying ground motions in an earthquake and tsunami early warning system. With a single receiver, PPP with ambiguity resolution can reproduce the positioning accuracy of conventional differential positioning techniques, but does not depend on any nearby reference stations which may also be displaced during an earthquake. As a result, the PPP data processing is more straightforward and efficient, suggesting that onsite displacement estimation can be carried out semi-autonomously at each GPS station and only a small amount of data, i.e. 3D displacements rather than raw measurements in the differential positioning, need to be transmitted to warning centers. Due to these merits and as part of a NASA-sponsored research effort, we have developed an operational real-time PPP system for Western North America, a vast region of tectonic deformation and significant seismic risk. A group of about 75 real-time GPS stations throughout North America and located far from western US coast (>300 km) is employed to estimate satellite-specific corrections (i.e. satellite clocks and fractional-cycle biases) with the predicted satellite orbits provided by the IGS (International GNSS Services). We note that our PPP implementation is challenged by geophysical constraints in North America and so all clients in the zone of deformation are outside the coverage of the reference network, and thus measurement errors originating in the atmosphere, satellite orbits and clocks are less correlated between the reference stations and the PPP clients. Despite this difficulty, the horizontal positioning accuracy at each PPP station is around 1 cm while the vertical better than 5 cm. This accuracy is sufficient to optimally combine the 1-Hz PPP-derived displacements with collocated (100 Hz) accelerometer data using a Kalman filter to estimate total displacement waveforms with millimeter-level accuracy. We also report on the testing of our approach in a simulated real-time environment for the 2006 Mw 6.0 Parkfield and 2010 Mw 7.2 El Mayor-Cucapah earthquakes.

  20. Assessment of precipitable water vapor derived from ground-based BeiDou observations with Precise Point Positioning approach

    NASA Astrophysics Data System (ADS)

    Li, Min; Li, Wenwen; Shi, Chuang; Zhao, Qile; Su, Xing; Qu, Lizhong; Liu, Zhizhao

    2015-01-01

    Precipitable water vapor (PWV) estimation from Global Positioning System (GPS) has been extensively studied and used for meteorological applications. However PWV estimation using the emerging BeiDou Navigation Satellite System (BDS) is very limited. In this paper the PWV estimation strategy and the evaluation of the results inferred from ground-based BDS observations using Precise Point Positioning (PPP) method are presented. BDS and GPS data from 10 stations distributed in the Asia-Pacific and West Indian Ocean regions during the year 2013 are processed using the PANDA (Position and Navigation Data Analyst) software package. The BDS-PWV and GPS-PWV are derived from the BDS-only and GPS-only observations, respectively. The PPP positioning differences between BDS-only and GPS-only show a standard deviation (STD) <1 cm in the east and north components and 1-3 cm in vertical component. The BDS-PWV and GPS-PWV at the HKTU station (Hong Kong, China) is compared with PWV derived from a radiosonde station (about 1 km distance) over a 6-month period. The GPS-PWV shows a good agreement with radiosonde-PWV with a bias of 0.002 mm and a STD of 2.49 mm while BDS-PWV has with a bias of -2.04 mm and STD 2.68 mm with respect to radiosonde-PWV. This indicates that the PWV estimated from the BDS can achieve similar precision as PWV from GPS. The BDS-PWV is compared to GPS-PWV at 10 stations. The mean bias and STD of their differences at 10 stations are 0.78 mm and 1.77 mm, respectively. The mean root mean square (RMS) value is 2.00 mm by considering the GPS-PWV as reference truth. This again confirms that the BDS-PWV has a good agreement with the GPS-PWV. It clearly indicates that the BDS is ready for the high precision meteorological applications in the Asia-Pacific and West Indian Ocean regions and that BDS alone can be used for PWV estimation with an accuracy comparable to GPS.

  1. Stationary early warning system for bird strike prevention in aviation

    NASA Astrophysics Data System (ADS)

    Vogel, Holger; Muenzberg, Mario; Schlemmer, Harry; Haan, Hubertus; Baader, Paul; Herden, Klaus; Fardi, Basel; Schlosshauer, Jan

    2009-05-01

    In case bird migration routes cross approach corridors near airports bird strike prevention with thermal imaging systems has advantages compared to others technologies i.e. RADAR systems. In our case a stereoscopic thermal imaging system sensitive in the mid wavelength range (3 - 5 μm) with high geometrical (640 × 512 pixel) and high thermal resolution (< 20 mK) measures in real time the swarm size, direction and velocity with high accuracy in order to give an early warning under all relevant weather conditions during day, night and twilight. The system is self-calibrating to keep the relative position of the paired stereoscopic thermal imagers in the sub-pixel range under all environmental conditions. The stereoscopic systems are placed in a sufficient distance to the crossing with the take-off or landing path to enable warning times of several minutes. Moreover the risk potential of the swarm is determined by taking the size of a single bird as well as the number of birds in the swarm into account. By using this information an arrival time of the swarm at the crossing point is determined and provided to the air security controllers together with the risk potential of the swarm.

  2. 14 CFR 29.631 - Bird strike.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  3. 14 CFR 29.631 - Bird strike.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  4. 14 CFR 29.631 - Bird strike.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  5. 14 CFR 29.631 - Bird strike.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  6. 14 CFR 29.631 - Bird strike.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  7. BeiDou phase bias estimation and its application in precise point positioning with triple-frequency observable

    NASA Astrophysics Data System (ADS)

    Gu, Shengfeng; Lou, Yidong; Shi, Chuang; Liu, Jingnan

    2015-10-01

    At present, the BeiDou system (BDS) enables the practical application of triple-frequency observable in the Asia-Pacific region, of many possible benefits from the additional signal; this study focuses on exploiting the contribution of zero difference (ZD) ambiguity resolution (AR) to the precise point positioning (PPP). A general modeling strategy for multi-frequency PPP AR is presented, in which, the least squares ambiguity decorrelation adjustment (LAMBDA) method is employed in ambiguity fixing based on the full variance-covariance ambiguity matrix generated from the raw data processing model. Because of the reliable fixing of BDS L1 ambiguity faces more difficulty, the LAMBDA method with partial ambiguity fixing is proposed to enable the independent and instantaneous resolution of extra wide-lane (EWL) and wide-lane (WL). This mechanism of sequential ambiguity fixing is demonstrated for resolving ZD satellite phase bias and performing triple-frequency PPP AR with two reference station networks with a typical baseline of up to 400 and 800 km, respectively. Tests show that about of the EWL and WL phase bias of BDS has a consistency of better than 0.1 cycle, and this value decreases to 80 % for L1 phase bias for Experiment I, while all the solutions of Experiment II have a similar RMS of about 0.12 cycles. In addition, the repeatability of the daily mean phase bias agree to 0.093 cycles and 0.095 cycles for EWL and WL on average, which is much smaller than 0.20 cycles of L1. To assess the improvement of fixed PPP brought by applying the third frequency signal as well as the above phase bias, various ambiguity fixing strategy are considered in the numerical demonstration. It is shown that the impact of the additional signal is almost negligible when only float solution involved. It is also shown that by fixing EWL and WL together, as opposed to the single ambiguity fixing, will leads to an improvement in PPP accuracy by about on average. Attributed to the efficient resolution of EWL WL within about 2 min in Experiment I, the 0.5 m level positioning can be achieved in 10 min for both horizontal and vertical, compared to 50 min for horizontal and 30 min for vertical by the NONE/EWL/WL fixed solution. While, for Experiment II, the improvement in the convergence can only be seen for the horizontal as the TTFF takes about 40 min for EWL and WL to be resolved.

  8. Impacts of real-time satellite clock errors on GPS precise point positioning-based troposphere zenith delay estimation

    NASA Astrophysics Data System (ADS)

    Shi, Junbo; Xu, Chaoqian; Li, Yihe; Gao, Yang

    2015-08-01

    Global Positioning System (GPS) has become a cost-effective tool to determine troposphere zenith total delay (ZTD) with accuracy comparable to other atmospheric sensors such as the radiosonde, the water vapor radiometer, the radio occultation and so on. However, the high accuracy of GPS troposphere ZTD estimates relies on the precise satellite orbit and clock products available with various latencies. Although the International GNSS Service (IGS) can provide predicted orbit and clock products for real-time applications, the predicted clock accuracy of 3 ns cannot always guarantee the high accuracy of troposphere ZTD estimates. Such limitations could be overcome by the use of the newly launched IGS real-time service which provides 5 cm orbit and 0.2-1.0 ns (an equivalent range error of 6-30 cm) clock products in real time. Considering the relatively larger magnitude of the clock error than that of the orbit error, this paper investigates the effect of real-time satellite clock errors on the GPS precise point positioning (PPP)-based troposphere ZTD estimation. Meanwhile, how the real-time satellite clock errors impact the GPS PPP-based troposphere ZTD estimation has also been studied to obtain the most precise ZTD solutions. First, two types of real-time satellite clock products are assessed with respect to the IGS final clock product in terms of accuracy and precision. Second, the real-time GPS PPP-based troposphere ZTD estimation is conducted using data from 34 selected IGS stations over three independent weeks in April, July and October, 2013. Numerical results demonstrate that the precision, rather than the accuracy, of the real-time satellite clock products impacts the real-time PPP-based ZTD solutions more significantly. In other words, the real-time satellite clock product with better precision leads to more precise real-time PPP-based troposphere ZTD solutions. Therefore, it is suggested that users should select and apply real-time satellite products with better clock precision to obtain more consistent real-time PPP-based ZTD solutions.

  9. System and Method of Locating Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)

    2002-01-01

    A system and method of determining locations of lightning strikes has been described. The system includes multiple receivers located around an area of interest, such as a space center or airport. Each receiver monitors both sound and electric fields. The detection of an electric field pulse and a sound wave are used to calculate an area around each receiver in which the lighting is detected. A processor is coupled to the receivers to accurately determine the location of the lighting strike. The processor can manipulate the receiver data to compensate for environmental variables such as wind, temperature, and humidity. Further, each receiver processor can discriminate between distant and local lightning strikes.

  10. Rydberg-Klein-Rees 1-Sigma-positive potential curve turning points for the isotopes of carbon monoxide

    NASA Technical Reports Server (NTRS)

    Chackerian, C., Jr.; Goorvitch, D.

    1982-01-01

    First order RKR turning points were computed for (C-12)O16, (C-12)O17, (C-13)O16, (C-12)O18, and (C-13)O18 for vibrational levels up to v = 40. These turning points should be useful in the numerical computation of matrix elements of powers of the internuclear separation.

  11. The differences in the isoelectric points of biofilm-positive and biofilm-negative Candida parapsilosis strains.

    PubMed

    Ruzicka, Filip; Horka, Marie; Hola, Veronika; Kubesova, Anna; Pavlik, Tomas; Votava, Miroslav

    2010-03-01

    The isoelectric points of 39 Candida parapsilosis strains were determined by means of capillary isoelectric focusing. The value of the isoelectric point corresponded well with cell surface hydrophobicity, as well as with the ability to form biofilm in these yeasts. PMID:20079385

  12. Atmosphere Mitigation in Precise Point Positioning Ambiguity Resolution for Earthquake Early Warning in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Geng, J.; Bock, Y.; Reuveni, Y.

    2014-12-01

    Earthquake early warning (EEW) is a time-critical system and typically relies on seismic instruments in the area around the source to detect P waves (or S waves) and rapidly issue alerts. Thanks to the rapid development of real-time Global Navigation Satellite Systems (GNSS), a good number of sensors have been deployed in seismic zones, such as the western U.S. where over 600 GPS stations are collecting 1-Hz high-rate data along the Cascadia subduction zone, San Francisco Bay area, San Andreas fault, etc. GNSS sensors complement the seismic sensors by recording the static offsets while seismic data provide highly-precise higher frequency motions. An optimal combination of GNSS and accelerometer data (seismogeodesy) has advantages compared to GNSS-only or seismic-only methods and provides seismic velocity and displacement waveforms that are precise enough to detect P wave arrivals, in particular in the near source region. Robust real-time GNSS and seismogeodetic analysis is challenging because it requires a period of initialization and continuous phase ambiguity resolution. One of the limiting factors is unmodeled atmospheric effects, both of tropospheric and ionospheric origin. One mitigation approach is to introduce atmospheric corrections into precise point positioning with ambiguity resolution (PPP-AR) of clients/stations within the monitored regions. NOAA generates hourly predictions of zenith troposphere delays at an accuracy of a few centimeters, and 15-minute slant ionospheric delays of a few TECU (Total Electron Content Unit) accuracy from both geodetic and meteorological data collected at hundreds of stations across the U.S. The Scripps Orbit and Permanent Array Center (SOPAC) is experimenting with a regional ionosphere grid using a few hundred stations in southern California, and the International GNSS Service (IGS) routinely estimates a Global Ionosphere Map using over 100 GNSS stations. With these troposphere and ionosphere data as additional observations, we can shorten the initialization period and improve the ambiguity resolution efficiency of PPP-AR. We demonstrate this with data collected by a cluster of Real-Time Earthquake Analysis for Disaster mItigation (READI) network stations in southern California operated by UNAVCO/PBO and SOPAC.

  13. The Verification of Influence of the Point "C" Position from Given Interval to Solving Systems with Highspeed Feedback

    NASA Astrophysics Data System (ADS)

    Baj?i?kov, Ingrida; Jurovat, Dominika

    2015-08-01

    This article deals with the design of effective numerical scheme for solving three point boundary value problems for second-order nonlinear singularly perturbed differential equations with initial conditions. Especially, it is focused on the analysis of the solutions when the point c from given interval is not the centre of this interval. The obtained system of nonlinear algebraic equations is solved by Newthon-Raphson method in MATLAB. It also verifies the convergence of approximate solutions of an original problem to the solution of reduced problem. We discuss the solution of a given problem with the situation when the point c is in the middle of the given interval.

  14. Finite fault modeling of oceanic strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Aderhold, K.; Abercrombie, R. E.

    2014-12-01

    The depth extent of seismic rupture in oceanic lithosphere is thought to be limited by the 600 to 800C isotherm with the thermal structure generally characterized by a half-space cooling model. However, previous studies constraining this limit represent a limited number of individual faults and earthquakes and use a wide range of different methods. Observations of significantly deep slip at the 800C isotherm, supershear rupture velocities, and along-strike differences in seismic slip have been made for oceanic strike slip earthquakes (McGuire and Beroza, 2012; Yue et al., 2013; McGuire et al., 2012). To examine how seismic rupture is controlled, we look at a variety of earthquakes in different settings using the same method of finite fault modeling. We choose the largest and best recorded oceanic strike-slip earthquakes from tectonic settings of interplate transform, intraplate fracture zones, and strike-slip plate boundaries. These earthquakes are located in the Indian Ocean, near the South Sandwich Islands, on the edge of the Scotia Plate, off the coast of Alaska, and west of Australia, rupturing lithosphere with ages from 0 to 70 My. We first determine first motion and point source mechanisms from the first arriving P waves and later arriving pP, sP, and SH waves. Using the nodal planes of these mechanisms, we perform finite fault modeling at a range of constant rupture velocities and hypocenter depths. We determine which slip asperities are well-constrained by limiting the extent of the preferred model until the fit to the data is affected significantly. The rupture directivity, rupture speed, depth extent of slip, and along-strike distribution of slip is then compared between events to identify relationships to the tectonic setting, thermal structure inferred from lithospheric age, or other possible mechanisms for controlling slip. These strike-slip earthquakes also provide examples of rupture along a bimaterial fault plane, which have been shown to have a relationship between stress loading direction, rupture directivity, and rupture speed by previous studies. The results of this study will determine seismic slip distribution in the relatively simple structure of oceanic lithosphere, and provide a comparison for the more complex structure of continental strike-slip faults.

  15. Single Station System and Method of Locating Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)

    2003-01-01

    An embodiment of the present invention uses a single detection system to approximate a location of lightning strikes. This system is triggered by a broadband RF detector and measures a time until the arrival of a leading edge of the thunder acoustic pulse. This time difference is used to determine a slant range R from the detector to the closest approach of the lightning. The azimuth and elevation are determined by an array of acoustic sensors. The leading edge of the thunder waveform is cross-correlated between the various acoustic sensors in the array to determine the difference in time of arrival, AT. A set of AT S is used to determine the direction of arrival, AZ and EL. The three estimated variables (R, AZ, EL) are used to locate a probable point of the lightning strike.

  16. Issues and Outcomes of Teachers' Strikes, 1955-65.

    ERIC Educational Resources Information Center

    Goergen, Joseph H.; Keough, John J.

    This study analyzes the patterns of 40 teacher strikes between 1955 and 1965 by looking at (1) the issues and demands and (2) the outcomes and settlements. It is hypothesized that (1) teacher strikes fall into discernible patterns, (2) functional relationships exist between certain strike issues and outcomes and the strike itself, (3) strikes can…

  17. Response to the DIAC Discussion Paper: "Review of the General Skilled Migration Points Test". Go8 Position Paper

    ERIC Educational Resources Information Center

    Group of Eight (NJ1), 2010

    2010-01-01

    The Group of Eight (Go8) applauds the government's intention to comprehensively reform the skilled migration program, and it welcomes the opportunity to submit this response to the General Skilled Migration (GSM) Points Test Discussion Paper. The Go8 has argued for some time that it is inappropriate to link international education to the skilled…

  18. Positive Behavior Supports: Using Class Dojo as a Token Economy Point System to Encourage and Maintain Good Behaviors

    ERIC Educational Resources Information Center

    Garcia, Eliana; Hoang, Dana

    2015-01-01

    The use of positive reinforcement sometimes gets lost in translation because educators forget the importance of acknowledging good behaviors. We instinctively tend to punish and give consequences because we often forget the importance of preventing undesired behaviors from occurring in the first place. More efforts should be spent on maintaining…

  19. The Effects of Height and Distance on the Force Production and Acceleration in Martial Arts Strikes

    PubMed Central

    Bolander, Richard P.; Neto, Osmar Pinto; Bir, Cynthia A.

    2009-01-01

    Almost all cultures have roots in some sort of self defence system and yet there is relatively little research in this area, outside of a sports related environment. This project investigated different applications of strikes from Kung Fu practitioners that have not been addressed before in the literature. Punch and palm strikes were directly compared from different heights and distances, with the use of a load cell, accelerometers, and high speed video. The data indicated that the arm accelerations of both strikes were similar, although the force and resulting acceleration of the target were significantly greater for the palm strikes. Additionally, the relative height at which the strike was delivered was also investigated. The overall conclusion is that the palm strike is a more effective strike for transferring force to an object. It can also be concluded that an attack to the chest would be ideal for maximizing impact force and moving an opponent off balance. Key Points It has been determined that the palm strike is more effective than the punch for developing force and for transferring momentum, most likely the result of a reduced number of rigid links and joints. A strike at head level is less effective than a strike at chest level for developing force and transferring momentum. Distance plays an effect on the overall force and momentum changes, and most likely is dependent on the velocity of the limb and alignment of the bones prior to impact. The teaching of self defence for novices and law enforcement would benefit from including the palm strike as a high priority technique. PMID:24474886

  20. A numerical investigation for the optimal positions and weighting coefficients of point dose measurements in the weighted CTDI

    NASA Astrophysics Data System (ADS)

    Choi, Jang-Hwan; Constantin, Dragos; Fahrig, Rebecca

    2015-03-01

    The mean dose over the central phantom plane (i.e., z = 0, dose maximum image) is useful in that it allows us to compare radiation dose levels across different CT scanners and acquisition protocols. The mean dose from a conventional CT scan with table translation is typically estimated by weighted CTDI (CTDIW). However, conventional CTDIW has inconsistent performance, depending on its weighting coefficients ("1/2 and 1/2" or "1/3 and 2/3") and acquisition protocols. We used a Monte Carlo (MC) model based on Geant4 (GEometry ANd Tracking) to generate dose profiles in the central plane of the CTDI phantom. MC simulations were carried out for three different sizes of z-collimator and different tube voltages (80, 100, or 120 kVp), a tube current of 80 mA, and an exposure time of 25 ms. We derived optimal weighting coefficients by taking the integral of the radial dose profiles. The first-order linear equation and the quadratic equation were used to fit the dose profiles along the radial direction perpendicular to the central plane, and the fitted profiles were revolved about the Z-axis to compute the mean dose (i.e., total volume under the fitted profiles/the central plane area). The integral computed using the linear equation resulted in the same equation as conventional CTDIW, and the integral computed using the quadratic equation resulted in a new CTDIW (CTDIMW) that incorporates different weightings ("2/3 and 1/3") and the middle dose point instead of the central dose point. Compared to the results of MC simulations, our new CTDIMW showed less error than the previous CTDIW methods by successfully incorporating the curvature of the dose profiles regardless of acquisition protocols. Our new CTDIMW will also be applicable to the AAPM-ICRU phantom, which has a middle dose point.

  1. Development of a GPS-aided motion measurement, pointing, and stabilization system for a Synthetic Aperture Radar. [Global Positioning System (GPS)

    SciTech Connect

    Fellerhoff, J.R.; Kohler, S.M.

    1991-01-01

    An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.

  2. The Chicago Teachers Strike and Its Public

    ERIC Educational Resources Information Center

    Shuffelton, Amy B.

    2014-01-01

    This article considers the 2012 Chicago Teachers Strike in light of John Dewey's "The Public and Its Problems." It engages Dewey's conceptualization of practical reason to challenge the educational reform movement's commitment to technocratic decision-making.

  3. Endgame Is Eyed in Chicago Strike

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2012-01-01

    A strike last week by some 29,000 teachers in Chicago pushed long-simmering tensions over deeply divisive school improvement ideas--including changes in teacher evaluation and the takeover or closure of underperforming schools--into the national spotlight. A framework for a tentative agreement emerged last Friday, and the union's house of…

  4. Teaching Striking/Fielding Concepts in Cricket

    ERIC Educational Resources Information Center

    Turner, Adrian P.

    2004-01-01

    This article presents activities for developing striking/fielding concepts in modified cricket games. Though not as familiar to American children, cricket is emerging as the second (to soccer) most popular game in the world. The novelty of the skills provides an appropriate learning challenge for all students while reinforcing concepts and

  5. Neuropathology of lightning-strike injuries.

    PubMed

    Kleinschmidt-DeMasters, B K

    1995-12-01

    When a person is struck by lightning a spectrum of neurologic damage can result. Approximately one third of the strikes prove to be fatal. The possibility of damage to the CNS relates to the type of lightning injury (direct strike, stride potential, or side flash), the intensity and duration of the current, the pathway of the current within the body, and secondary injuries to brain either from cardiac arrest and hypoxia or from physical trauma. Direct strikes to the head have a high degree of fatality and often result in petechiae or larger brain hemorrhages. Although there may be some predilection for the petechiae to occur in the brainstem, the larger hemorrhages may be particularly located near the pathway of the electrical current and result from direct damage to brain vasculature. Enlarged perivascular spaces seen histologically are relatively subtle; they have been attributed to the effects of gas bubbles from electrolysis, heat formation, or both. Small vessel thrombi and neuronal changes may be present nearby. Some brain tissue softening and edema may be direct effects of passage of current. Often, however, hypoxic encephalopathy and cerebral edema occur following cardiopulmonary arrest when the passage of the current through the body presumably generates cardiac arrhythmias. Considerably less is known about the spinal cord injuries in lightning strike, although one detailed recent study suggests that demyelination may be an underlying mechanism. Similarly, myelin damage appears to be a feature of electrical and possibly lightning injury to the peripheral nervous system. PMID:8848648

  6. Endgame Is Eyed in Chicago Strike

    ERIC Educational Resources Information Center

    Sawchuk, Stephen

    2012-01-01

    A strike last week by some 29,000 teachers in Chicago pushed long-simmering tensions over deeply divisive school improvement ideas--including changes in teacher evaluation and the takeover or closure of underperforming schools--into the national spotlight. A framework for a tentative agreement emerged last Friday, and the union's house of

  7. Registration of 'FirstStrike' Slender Wheatgrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'FirstStrike' slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners] was developed by a research team at the USDA-ARS-Forage and Range Research Laboratory and collaborators at the United States Army - Engineer Research and Development Center and was released on 16 October 2006. FirstStri...

  8. Teaching Striking/Fielding Concepts in Cricket

    ERIC Educational Resources Information Center

    Turner, Adrian P.

    2004-01-01

    This article presents activities for developing striking/fielding concepts in modified cricket games. Though not as familiar to American children, cricket is emerging as the second (to soccer) most popular game in the world. The novelty of the skills provides an appropriate learning challenge for all students while reinforcing concepts and…

  9. What to Expect During a Teachers' Strike.

    ERIC Educational Resources Information Center

    Long, Jerri

    1987-01-01

    This two-page table charts the range of union activities, their adversarial intent, and possible administrative counterstrategies during a typical teacher strike. Twenty-four activities are covered, from peaceful demonstrations (like picketing), marches, and candlelight vigils, to harassments like nails in tires and telephone threats. (MLH)

  10. Protecting Your Park When Lightning Strikes.

    ERIC Educational Resources Information Center

    Frydenlund, Marvin M.

    1987-01-01

    A formula for assessing specific risk of lightning strikes is provided. Recent legal cases are used to illustrate potential liability. Six actions park managers can take to minimize danger from lightning are presented, and commonsense rules which should be publicly posted are listed. (MT)

  11. Impact of lightning strikes on hospital functions.

    PubMed

    Mortelmans, Luc J M; Van Springel, Gert L J; Van Boxstael, Sam; Herrijgers, Jan; Hoflacks, Stefaan

    2009-01-01

    Two regional hospitals were struck by lightning during a one-month period. The first hospital, which had 236 beds, suffered a direct strike to the building. This resulted in a direct spread of the power peak and temporary failure of the standard power supply. The principle problems, after restoring standard power supply, were with the fire alarm system and peripheral network connections in the digital radiology systems. No direct impact on the hardware could be found. Restarting the servers resolved all problems. The second hospital, which had 436 beds, had a lightning strike on the premises and mainly experienced problems due to induction. All affected installations had a cable connection from outside in one way or another. The power supplies never were endangered. The main problem was the failure of different communication systems (telephone, radio, intercom, fire alarm system). Also, the electronic entrance control went out. During the days after the lightening strike, multiple software problems became apparent, as well as failures of the network connections controlling the technical support systems. There are very few ways to prepare for induction problems. The use of fiber-optic networks can limit damage. To the knowledge of the authors, these are the first cases of lightning striking hospitals in medical literature. PMID:20066646

  12. Geometrical and total efficiencies of CdZnTe rectangular parallelepiped detector using arbitrary positioned point, plane, and volumetric sources

    NASA Astrophysics Data System (ADS)

    Hamzawy, A.; Badawi, Mohamed S.; Thabet, Abouzeid A.; Gouda, Mona M.; El-Khatib, Ahmed M.; Abbas, Mahmoud I.

    2016-02-01

    Gamma-ray detectors are widely used in many fields like environmental measurements, medicine, space science, and industry, where the detector geometrical, total, photopeak efficiencies and peak-to-total ratio could be required. The calculation of the detector efficiency depends mainly on the value of the geometrical efficiency, which depends on the solid angle subtended by the source-detector system. The present work introduces a direct analytical method to calculate the geometrical and total efficiencies of CdZnTe gamma-ray detector using off-axis isotropic radiating γ-ray [point, disk, and cylindrical] sources. To test the validity of the present work, the results are compared with some published data and also to prove how much it is important to determine the efficiency of difficult gamma-ray detection arrangement.

  13. Position-dependent velocity of an effective temperature point for the estimation of the thermal diffusivity of solids

    NASA Astrophysics Data System (ADS)

    Balachandar, Settu; Shivaprakash, N. C.; Kameswara Rao, L.

    2016-01-01

    A new approach is proposed to estimate the thermal diffusivity of optically transparent solids at ambient temperature based on the velocity of an effective temperature point (ETP), and by using a two-beam interferometer the proposed concept is corroborated. 1D unsteady heat flow via step-temperature excitation is interpreted as a ‘micro-scale rectilinear translatory motion’ of an ETP. The velocity dependent function is extracted by revisiting the Fourier heat diffusion equation. The relationship between the velocity of the ETP with thermal diffusivity is modeled using a standard solution. Under optimized thermal excitation, the product of the ‘velocity of the ETP’ and the distance is a new constitutive equation for the thermal diffusivity of the solid. The experimental approach involves the establishment of a 1D unsteady heat flow inside the sample through step-temperature excitation. In the moving isothermal surfaces, the ETP is identified using a two-beam interferometer. The arrival-time of the ETP to reach a fixed distance away from heat source is measured, and its velocity is calculated. The velocity of the ETP and a given distance is sufficient to estimate the thermal diffusivity of a solid. The proposed method is experimentally verified for BK7 glass samples and the measured results are found to match closely with the reported value.

  14. Comparisons of line-of-sight water vapor observations using the global positioning system and a pointing microwave radiometer.

    SciTech Connect

    Braun, J.; Rocken, C.; Liljegren, J. C.; Environmental Research; Univ. Corporation for Atmospheric Research

    2003-05-01

    Line-of-sight measurements of integrated water vapor from a global positioning system (GPS) receiver and a microwave radiometer are compared. These two instruments were collocated at the central facility of the Department of Energy's Atmospheric Radiation Measurement Program's Southern Great Plains region, near Lamont, Oklahoma. The comparison was made using 47 days of observations in May and June of 2000. Weather conditions during this time period were variable with total integrated water vapor ranging from less than 10 to more than 50 mm. To minimize errors in the microwave radiometer observations, observations were compared during conditions when the liquid water measured by the radiometer was less than 0.1 mm. The linear correlation of the observations between the two instruments is 0.99 with a root-mean-square difference of the GPS water vapor to a linear fit of the microwave radiometer of 1.3 mm. The results from these comparisons are used to evaluate the ability of networks of GPS receivers to measure instantaneous line-of-sight integrals of water vapor. A discussion and analysis is provided regarding the additional information of the water vapor field contained in these observations compared to time- and space-averaged zenith and gradient measurements.

  15. Position-addressable digital laser scanning point fluorescence microscopy with a Blu-ray disk pickup head

    PubMed Central

    Tsai, Rung-Ywan; Chen, Jung-Po; Lee, Yuan-Chin; Huang, Chun-Chieh; Huang, Tai-Ting; Chiang, Hung-Chih; Cheng, Chih-Ming; Lo, Feng-Hsiang; Chang, Sheng-Li; Weng, Kuo-Yao; Chung, Lung-Pin; Chen, Jyh-Chern; Tiao, Golden

    2014-01-01

    A compact and position-addressable blue ray scanning microscope (BSM) based on a commercially available Blu-ray disk pickup head (PUH) is developed for cell imaging with high resolution and low cost. The BSM comprises two objective lenses with numerical apertures (NAs) of 0.85 and 0.6 for focusing blue and red laser beams, respectively, on the sample slide. The blue and red laser beams are co-located adjacent to each other and move synchronously. A specially designed sample slide is used with a sample area and an address-patterned area for sample holding and address recognition, respectively. The blue laser beam is focused on the sample area and is used for fluorescent excitation and image capturing, whereas the red laser beam is focused on the address-patterned area and is used for address recognition and dynamic focusing. The address-patterned area is divided into 310 sectors. The cell image of each sector of the sampling area has a corresponding address pattern. Fluorescence images of monkey-derived kidney epithelial cells and fibroblast cells in which the F-actin is stained with fluorophore phalloidin CF 405 are measured by the BSM, with results comparable to those measured by a Leica TCS CP2 confocal microscope. The cell image of an area of interest can be easily tracked based on the coded address, and a large-area sample image can be accurately reconstructed from the sector images. PMID:24575338

  16. Costs of strikes between vulnerable missile forces

    SciTech Connect

    Canavan, G.H.

    1997-02-01

    This note derives the first and second strike magnitudes and costs for strikes between vulnerable missile forces with multiple warheads. The extension to mixes with invulnerable missiles is performed in a companion note. Stability increases as the number of weapons per missile is reduced. The optimal allocation of weapons between missiles and value is significant in predicting the stability impact of the reduction of the number of weapons per missile at large numbers of missiles, less significant in reducing the number of missiles for fixed weapons per missile. At low numbers of missiles, the stability indices for singlet and triplet configurations are comparable, as are the number of weapons each would deliver on value targets.

  17. Systems tunnel linear shaped charge lightning strike

    NASA Technical Reports Server (NTRS)

    Cook, M.

    1989-01-01

    Simulated lightning strike testing of the systems tunnel linear shaped charge (LSC) was performed at the Thiokol Lightning Test Complex in Wendover, Utah, on 23 Jun. 1989. The test article consisted of a 160-in. section of the LSC enclosed within a section of the systems tunnel. The systems tunnel was bonded to a section of a solid rocket motor case. All test article components were full scale. The systems tunnel cover of the test article was subjected to three discharges (each discharge was over a different grounding strap) from the high-current generator. The LSC did not detonate. All three grounding straps debonded and violently struck the LSC through the openings in the systems tunnel floor plates. The LSC copper surface was discolored around the areas of grounding strap impact, and arcing occurred at the LSC clamps and LSC ends. This test verified that the present flight configuration of the redesigned solid rocket motor systems tunnel, when subjected to simulated lightning strikes with peak current levels within 71 percent of the worst-case lightning strike condition of NSTS-07636, is adequate to prevent LSC ignition. It is therefore recommended that the design remain unchanged.

  18. Resistance, mobilization and militancy: nurses on strike.

    PubMed

    Briskin, Linda

    2012-12-01

    Drawing on nurses' strikes in many countries, this paper explores nurse militancy with reference to professionalism and the commitment to service; patriarchal practices and gendered subordination; and proletarianization and the confrontation with healthcare restructuring. These deeply entangled trajectories have had a significant impact on the work, consciousness and militancy of nurses and have shaped occupation-specific forms of resistance. They have produced a pattern of overlapping solidarities--occupational solidarity, gendered alliances and coalitions around healthcare restructuring--which have supported, indeed promoted, militancy among nurses, despite the multiple forces arrayed against them. The professional commitments of nurses to the provision of care have confronted healthcare restructuring, nursing shortages, intensification of work, precarious employment and gendered hierarchies with a militant discourse around the public interest, and a reconstitution and reclamation of 'caring', what I call the politicisation of caring. In fact, nurses' dedication to caring work in the late twentieth and early twenty-first centuries may encourage rather than dissuade them from going on strike. This paper uses a trans-disciplinary methodology, qualitative material in the form of strike narratives constructed from newspaper archives, and references to the popular and scholarly literature on nursing militancy. PMID:22059465

  19. Assessment of Three Tropospheric Delay Models (IGGtrop, EGNOS and UNB3m) Based on Precise Point Positioning in the Chinese Region

    PubMed Central

    Zhang, Hongxing; Yuan, Yunbin; Li, Wei; Li, Ying; Chai, Yanju

    2016-01-01

    Tropospheric delays are one of the main sources of errors in the Global Navigation Satellite System (GNSS). They are usually corrected by using tropospheric delay models, which makes the accuracy of the models rather critical for accurate positioning. To provide references for suitable models to be chosen for GNSS users in China, we conduct herein a comprehensive study of the performances of the IGGtrop, EGNOS and UNB3m models in China. Firstly, we assess the models using 5 years’ Global Positioning System (GPS) derived Zenith Tropospheric Delay (ZTD) series from 25 stations of the Crustal Movement Observation Network of China (CMONOC). Then we study the effects of the models on satellite positioning by using various Precise Point Positioning (PPP) cases with different tropospheric delay resolutions, the observation data processed in PPP is from 21 base stations of CMONOC for a whole year of 2012. The results show that: (1) the Root Mean Square (RMS) of the IGGtrop model is about 4.4 cm, which improves the accuracy of ZTD estimations by about 24% for EGNOS and 19% for UNB3m; (2) The positioning error in the vertical component of the PPP solution obtained by using the IGGtrop model is about 15.0 cm, which is about 30% and 21% smaller than those of the EGNOS and UNB3m models, respectively. In summary, the IGGtrop model achieves the best performance among the three models in the Chinese region. PMID:26805834

  20. Assessment of Three Tropospheric Delay Models (IGGtrop, EGNOS and UNB3m) Based on Precise Point Positioning in the Chinese Region.

    PubMed

    Zhang, Hongxing; Yuan, Yunbin; Li, Wei; Li, Ying; Chai, Yanju

    2016-01-01

    Tropospheric delays are one of the main sources of errors in the Global Navigation Satellite System (GNSS). They are usually corrected by using tropospheric delay models, which makes the accuracy of the models rather critical for accurate positioning. To provide references for suitable models to be chosen for GNSS users in China, we conduct herein a comprehensive study of the performances of the IGGtrop, EGNOS and UNB3m models in China. Firstly, we assess the models using 5 years' Global Positioning System (GPS) derived Zenith Tropospheric Delay (ZTD) series from 25 stations of the Crustal Movement Observation Network of China (CMONOC). Then we study the effects of the models on satellite positioning by using various Precise Point Positioning (PPP) cases with different tropospheric delay resolutions, the observation data processed in PPP is from 21 base stations of CMONOC for a whole year of 2012. The results show that: (1) the Root Mean Square (RMS) of the IGGtrop model is about 4.4 cm, which improves the accuracy of ZTD estimations by about 24% for EGNOS and 19% for UNB3m; (2) The positioning error in the vertical component of the PPP solution obtained by using the IGGtrop model is about 15.0 cm, which is about 30% and 21% smaller than those of the EGNOS and UNB3m models, respectively. In summary, the IGGtrop model achieves the best performance among the three models in the Chinese region. PMID:26805834

  1. Overview of cenozoic strike-slip displacement of the caribbean plate

    SciTech Connect

    Mann, P.

    1985-01-01

    Geologic and tectonic studies in the Caribbean region have traditionally focused on Cretaceous and Paleogene arc rocks which, for the most part, record a long period (approx. = 100 Ma) of plate convergence. Since the recognition of the plate structure of the Caribbean by Molnar and Sykes in 1969, there has been steadily increasing interest in mapping widespread ares of Neogene sedimentary and volcanic rocks that generally record a long period (65.-40 Ma) of eastward displacement of the Caribbean plate relative to the Americas. The purpose of this talk is to review different aspects of present knowledge on this strike-slip displacement, namely: 1) location of major strike-slip faults within the northern and southern plate boundary zones; 2) sense, offset, rate of slip of major strike-slip faults; 3) secondary deformational features related to strike-slip displacements; 4) intraplate deformational features related to interplate strike-slip movements; 5) relation of seismicity to major strike-slip faults; and 6) constraints imposed by strike-slip fault systems on plate motion models. Based on these observations, several critical problems which future studies might help resolve are pointed out.

  2. Streptomycin-resistance of Euglena gracilis chloroplasts: identification of a point mutation in the 16S rRNA gene in an invariant position.

    PubMed

    Montandon, P E; Nicolas, P; Schrmann, P; Stutz, E

    1985-06-25

    We sequenced the chloroplast 16S rRNA gene of two Euglena gracilis mutants which contain streptomycin-resistant chloroplasts (Smr 139.12/4 and Smr 139.20/2). These mutants are known to contain a single intact rrn operon per circular chloroplast genome. Nucleotide sequence comparison between a 16S rRNA gene of wild type Euglena gracilis, strain Z, with streptomycin-sensitive chloroplasts, and the 16S rRNA gene of both Smr-strains reveals a single base change (C to T) at position 876. This position is equivalent to the invariant position 912 of the E. coli 16S rRNA gene. The analogous position is also conserved in all chloroplast small subunit RNA genes from lower and higher plants sequenced so far. Light dependent protein synthesis with purified chloroplasts from streptomycin-resistant cells is not inhibited by streptomycin. Based on the results reported here we postulate linkage between the observed point mutation on the 16S rRNA gene and streptomycin-resistance of chloroplast 70S ribosomes. PMID:3925438

  3. Strike-slip sedimentation: Dead Sea basin

    SciTech Connect

    Manspeizer, W.

    1986-05-01

    The Dead Sea rift extends for 1000 km along a transform plate boundary that has had left-lateral displacement of 150 km since the Miocene. The rift consists of a series of en-echelon, left-stepping (looking north), north-striking, strike-slip faults that are joined by a series of grabens (e.g., the Dead Sea basin). This basin developed as an asymmetric rhomb-shaped graben with nearly vertical, north-striking normal border faults (east and west margins), north-northeast-dipping listric normal faults (south margin), and a south-facing inclined basement (north margin). Displacement along the transform produced three basins, whose depocenters migrated north where they received Miocene fluvial clastics, Pliocene marine evaporites, and Pleistocene-Holocene lacustrine sediments. Graben filling today is governed largely by tectonism, which modifies rift climates and morphology. As warm moist air from the Mediterranean Sea rises over the rift shoulders, it cools adiabatically, yielding up to 900 mm of rain water for high discharge, ephemeral streams that prograde vast prisms of coalescing shallow water fan deltas along the western border fault. The eastern basin margin, by contrast, is dominated by an active transform boundary, a narrow shelf, and a spectacular deep (750 m below MSL) that receives deep water clastics. Whereas the northern margin of the basin receives fine-grained clastics from the prograding delta of the Jordan River (a perennial stream, whose drainage basin lies in a humid terrane far to the north), the southern margin is dominated by evaporites that are precipitated in shallow water basins (upon adiabatic warming of descending air).

  4. Acute transient hemiparesis induced by lightning strike.

    PubMed

    Rahmani, Seyed Hesam; Faridaalaee, Gholamreza; Jahangard, Samira

    2015-07-01

    According to data from the National Oceanic and Atmospheric Administration,in the years from 1959 to 1994, lightning was responsible for more than 3000 deaths and nearly 10,000 casualties. The most important characteristic features of lightning injuries are multisystem involvement and widely variable severity. Lightning strikes are primarily a neurologic injury that affects all 3 components of the nervous system: central, autonomic,and peripheral. Neurologic complications of lightning strikes vary from transient benign symptoms to permanent disability. Many patients experience a temporary paralysis called keraunoparalysis. Here we reported a 22-year-old mountaineer man with complaining of left sided hemiparesis after being hit by a lightning strike in the mountain 3 hours ago. There was no loss of consciousness at hitting time. On arrival the patient was alert, awake and hemodynamically stable. In neurologic examination cranial nerves were intact, left sided upper and lower extremity muscle force was I/V with a combination of complete sensory loss, and right-sided muscle force and sensory examination were normal. There is not any evidence of significant vascular impairment in the affected extremities. Brain MRI and CT scan and cervical MRI were normal. During 2 days of admission, with intravenous hydration, heparin 5000 unit SC q12hr and physical therapy of the affected limbs, motor and sensory function improved and was normal except mild paresthesia. He was discharged 1 day later for outpatient follow up while vitamin B1 100mg orally was prescribed.Paresthesia improved after 3 days without further sequels. PMID:25650360

  5. Lightning strike-induced brachial plexopathy.

    PubMed

    Bhargava, Amita N; Kasundra, Gaurav M; Khichar, Subhakaran; Bhushan, Bharat S K

    2014-10-01

    We describe a patient who presented with a history of lightning strike injury. Following the injury, he sustained acute right upper limb weakness with pain. Clinically, the lesion was located to the upper and middle trunk of the right brachial plexus, and the same confirmed with electrophysiological studies. Nerve damage due to lightning injuries is considered very rare, and a plexus damage has been described infrequently, if ever. Thus, the proposed hypothesis that lightning rarely causes neuropathy, as against high-voltage electric current, due to its shorter duration of exposure not causing severe burns which lead to nerve damage, needs to be reconsidered. PMID:25288846

  6. Direct strike lightning measurement system. [for aircraft

    NASA Technical Reports Server (NTRS)

    Thomas, M. E.

    1981-01-01

    A research data system developed for in-flight measurement of direct and nearby lightning-strike characteristics is described. The measurement system consists of a wide-band analog recorder which records the continuous lightning scenario and fast sample-rate digital transient recorders with augmented memory capacity for increased time resolution of specific times of interest. Electromagnetic sensors with bandwidths exceeding 100 MHz are used which respond to rates of change of the quantities being measured. Data system immunity from electromagnetic interference is accomplished by the use of a dynamotor for power isolation, shielded system enclosure and fiber-optic data links.

  7. Optimal Positive Cutoff Points for careHPV Testing of Clinician- and Self-Collected Specimens in Primary Cervical Cancer Screening: an Analysis from Rural China

    PubMed Central

    Kang, Le-Ni; Jeronimo, Jose; Zhao, Fang-Hui; Chen, Wen; Valdez, Melissa; Zhang, Xun; Bansil, Pooja; Paul, Proma; Bai, Ping; Peck, Roger; Li, Jing; Chen, Feng; Stoler, Mark H.

    2014-01-01

    careHPV, a lower-cost DNA test for human papillomavirus (HPV), is being considered for cervical cancer screening in low- and middle-income countries. However, not a single large-scaled study exists to investigate the optimal positive cutoff point of careHPV test. We pooled data for 9,785 women participating in two individual studies conducted from 2007 to 2011 in rural China. Woman underwent multiple screening tests, including careHPV on clinician-collected specimens (careHPV-C) and self-collected specimens (careHPV-S), and Hybrid Capture 2 on clinician-collected specimens (HC2-C) as a reference standard. The primary endpoint was cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) (n = 127), and secondary endpoint was CIN2+ (n = 213). The area under the curves (AUCs) for HC2-C and careHPV-C were similar (0.954 versus 0.948, P = 0.166), and better than careHPV-S (0.878; P < 0.001 versus both). The optimal positive cutoff points for HC2-C, careHPV-C, and careHPV-S were 1.40, 1.74, and 0.85, respectively. At the same cutoff point, careHPV-C was not significantly less sensitive and more specific for CIN3+ than HC2-C, and careHPV-S was significantly less sensitive for CIN3+ than careHPV-C and HC2-C. Raising the cutoff point of careHPV-C from 1.0 to 2.0 could result in nonsignificantly lower sensitivity but significantly higher specificity. Similar results were observed using CIN2+ endpoint. careHPV using either clinician- or self-collected specimens performed well in detecting cervical precancer and cancer. We found that the optimal cutoff points of careHPV were 2.0 on clinician-collected specimens and 1.0 on self-collected specimens. PMID:24671789

  8. Optimal positive cutoff points for careHPV testing of clinician- and self-collected specimens in primary cervical cancer screening: an analysis from rural China.

    PubMed

    Kang, Le-Ni; Jeronimo, Jose; Qiao, You-Lin; Zhao, Fang-Hui; Chen, Wen; Valdez, Melissa; Zhang, Xun; Bansil, Pooja; Paul, Proma; Bai, Ping; Peck, Roger; Li, Jing; Chen, Feng; Stoler, Mark H; Castle, Philip E

    2014-06-01

    careHPV, a lower-cost DNA test for human papillomavirus (HPV), is being considered for cervical cancer screening in low- and middle-income countries. However, not a single large-scaled study exists to investigate the optimal positive cutoff point of careHPV test. We pooled data for 9,785 women participating in two individual studies conducted from 2007 to 2011 in rural China. Woman underwent multiple screening tests, including careHPV on clinician-collected specimens (careHPV-C) and self-collected specimens (careHPV-S), and Hybrid Capture 2 on clinician-collected specimens (HC2-C) as a reference standard. The primary endpoint was cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) (n = 127), and secondary endpoint was CIN2+ (n = 213). The area under the curves (AUCs) for HC2-C and careHPV-C were similar (0.954 versus 0.948, P = 0.166), and better than careHPV-S (0.878; P < 0.001 versus both). The optimal positive cutoff points for HC2-C, careHPV-C, and careHPV-S were 1.40, 1.74, and 0.85, respectively. At the same cutoff point, careHPV-C was not significantly less sensitive and more specific for CIN3+ than HC2-C, and careHPV-S was significantly less sensitive for CIN3+ than careHPV-C and HC2-C. Raising the cutoff point of careHPV-C from 1.0 to 2.0 could result in nonsignificantly lower sensitivity but significantly higher specificity. Similar results were observed using CIN2+ endpoint. careHPV using either clinician- or self-collected specimens performed well in detecting cervical precancer and cancer. We found that the optimal cutoff points of careHPV were 2.0 on clinician-collected specimens and 1.0 on self-collected specimens. PMID:24671789

  9. Squeezing, striking, and vocalizing: Is number representation fundamentally spatial?

    PubMed

    Nez, Rafael; Doan, D; Nikoulina, Anastasia

    2011-08-01

    Numbers are fundamental entities in mathematics, but their cognitive bases are unclear. Abundant research points to linear space as a natural grounding for number representation. But, is number representation fundamentally spatial? We disentangle number representation from standard number-to-line reporting methods, and compare numerical estimations in educated participants using line-reporting with three nonspatial reporting conditions (squeezing, bell-striking, and vocalizing). All three cases of nonspatial-reporting consistently reproduced well-established results obtained with number-line methods. Furthermore, unlike line-reporting-and congruent with the psychophysical Weber-Fechner law-nonspatial reporting systematically produced logarithmic mappings for all nonsymbolic stimuli. Strikingly, linear mappings were obtained exclusively in conditions with culturally mediated elements (e.g., words). These results suggest that number representation is not fundamentally spatial, but builds on a deeper magnitude sense that manifests spatially and nonspatially mediated by magnitude, stimulus modality, and reporting condition. Number-to-space mappings-although ubiquitous in the modern world-do not seem to be rooted directly in brain evolution but have been culturally privileged and enhanced. PMID:21640338

  10. A new comprehensive 2D model of the point spread functions of the XMM-Newton EPIC telescopes: spurious source suppression and improved positional accuracy

    NASA Astrophysics Data System (ADS)

    Read, A. M.; Rosen, S. R.; Saxton, R. D.; Ramirez, J.

    2011-10-01

    Aims: We describe here a new full 2D parameterization of the PSFs of the three XMM-Newton EPIC telescopes as a function of instrument, energy, off-axis angle and azimuthal angle, covering the whole field-of-view (FoV) of the three EPIC detectors. It models the general PSF envelopes, the primary and secondary spokes, their radial dependencies, and the large-scale azimuthal variations. Methods: This PSF model has been constructed via the stacking and centering of a large number of bright, but not significantly piled-up point sources from the full FoV of each EPIC detector, and azimuthally filtering the resultant PSF envelopes to form the spoke structures and the gross azimuthal shapes observed. Results: This PSF model is available for use within the XMM-Newton science analysis system via the usage of current calibration files XRTi_XPSF_0011.CCF and later versions. Initial source-searching tests showed substantial reductions in the numbers of spurious sources being detected in the wings of bright point sources. Furthermore, we have uncovered a systematic error in the previous PSF system, affecting the entire mission to date, whereby returned source RA and Dec values are seen to vary sinusoidally about the true position (amplitude ≈0.8″) with source azimuthal position. Conclusions: The new PSF system is now available and is seen as a major improvement with regard to the detection of spurious sources. The new PSF also largely removes the discovered astrometry error and is seen to improve the positional accuracy of EPIC. The modular nature of the PSF system allows for further refinements in the future.

  11. 20 CFR 345.402 - Strikes or work stoppages.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Strikes or work stoppages. 345.402 Section... INSURANCE ACT EMPLOYERS' CONTRIBUTIONS AND CONTRIBUTION REPORTS Benefit Charging 345.402 Strikes or work stoppages. If benefits are payable to an employee for days of unemployment resulting from a strike or...

  12. 20 CFR 345.402 - Strikes or work stoppages.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Strikes or work stoppages. 345.402 Section 345... INSURANCE ACT EMPLOYERS' CONTRIBUTIONS AND CONTRIBUTION REPORTS Benefit Charging 345.402 Strikes or work stoppages. If benefits are payable to an employee for days of unemployment resulting from a strike or...

  13. Sensitivity of predictions in an effective model: Application to the chiral critical end point position in the Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Biguet, Alexandre; Hansen, Hubert; Costa, Pedro; Borgnat, Pierre; Brugire, Timothe

    2015-09-01

    The measurement of the position of the chiral critical end point (CEP) in the QCD phase diagram is under debate. While it is possible to predict its position by using effective models specifically built to reproduce some of the features of the underlying theory (QCD), the quality of the predictions ( e.g., the CEP position) obtained by such effective models, depends on whether solving the model equations constitute a well- or ill-posed inverse problem. Considering these predictions as being inverse problems provides tools to evaluate if the problem is ill-conditioned, meaning that infinitesimal variations of the inputs of the model can cause comparatively large variations of the predictions. If it is ill-conditioned, it has major consequences because of finite variations that could come from experimental and/or theoretical errors. In the following, we shall apply such a reasoning on the predictions of a particular Nambu-Jona-Lasinio model within the mean field + ring approximations, with special attention to the prediction of the chiral CEP position in the ( T- ?) plane. We find that the problem is ill-conditioned ( i.e. very sensitive to input variations) for the T-coordinate of the CEP, whereas, it is well-posed for the ?-coordinate of the CEP. As a consequence, when the chiral condensate varies in a 10MeV range, ? CEP varies far less. As an illustration to understand how problematic this could be, we show that the main consequence when taking into account finite variation of the inputs, is that the existence of the CEP itself cannot be predicted anymore: for a deviation as low as 0.6% with respect to vacuum phenomenology (well within the estimation of the first correction to the ring approximation) the CEP may or may not exist.

  14. Ionospheric corrections estimation in a local GNSS permanent stations network: improvement of Code Point Positioning at sub-metric accuracy level

    NASA Astrophysics Data System (ADS)

    Brunini, C.; Crespi, M.; Mazzoni, A.

    2008-12-01

    It is well know that GNSS permanent networks for real-time positioning were mainly designed to generate and transmit products for RTK (or Network-RTK) positioning. In this context, RTK products are restricted to users equipped with geodetic-class receivers. This work is a first step toward using a local network of permanent GNSS stations to generate and transmit real time products that could remarkably improve positioning accuracy for C/A receiver users. A simple experiment was carried out based on 3 consecutive days of data from 3 permanent stations that belong to the RESNAP-GPS network (w3.uniroma1.it/resnap-gps), located at the Lazio Region (Central Italy) and managed by DITS-Area di Geodesia e Geomatica, Sapienza University of Rome. In the first step the RINEX files were corrected for the differential code biases according to IGS recommendations and then processed with Bernese 5.0 CODSPP module (single point positioning using code measurements), using IGS precise ephemeris and clocks. One position per epoch (every 30 seconds) was estimated for P1 and for the ionosphere free combination (P3). The accuracy obtained with the P3 combination for the vertical component, which ranged from -1 to +1 m, was taken as the reference for the following discussion. For P1 observations, the vertical coordinate errors showed a typical signature due to the ionospheric activity: higher errors for day-time (up to 5 m) and smaller ones for night-time (around 1.5 m). In order to improve the accuracy of the P1 solution, ionospheric corrections were estimated using the La Plata Ionospheric Model, based on the dual-frequency observations from the RESNAP-GPS network. Those corrections were applied to the RINEX files of a probing station located within the reference network. With this procedure, the vertical coordinate errors were reduced to the range from -0.8 to 0.8 m. This methodological approach shows the possibility to remarkably improve the real time positioning based on Code measurements only using ionospheric corrections estimations and CODE DCB products.

  15. Ionospheric corrections estimation in a local GNSS permanent stations network: improvement of Code Point Positioning at sub-metric accuracy level

    NASA Astrophysics Data System (ADS)

    Brunini, C.; Crespi, M.; Mazzoni, A.

    2009-04-01

    It is well know that GNSS permanent networks for real-time positioning were mainly designed to generate and transmit products for RTK (or Network-RTK) positioning. In this context, RTK products are restricted to users equipped with geodetic-class receivers. This work is a first step toward using a local network of permanent GNSS stations to generate and transmit real time products that could remarkably improve positioning accuracy for C/A receiver users. A simple experiment was carried out based on 3 consecutive days of data from 3 permanent stations that belong to the RESNAP-GPS network (w3.uniroma1.it/resnap-gps), located at the Lazio Region (Central Italy) and managed by DITS-Area di Geodesia e Geomatica, Sapienza University of Rome. In the first step the RINEX files were corrected for the differential code biases according to IGS recommendations and then processed with Bernese 5.0 CODSPP module (single point positioning using code measurements), using IGS precise ephemeris and clocks. One position per epoch (every 30 seconds) was estimated for P1 and for the ionosphere free combination (P3). The accuracy obtained with the P3 combination for the vertical component, which ranged from -1 to +1 m, was taken as the reference for the following discussion. For P1 observations, the vertical coordinate errors showed a typical signature due to the ionospheric activity: higher errors for day-time (up to 5 m) and smaller ones for night-time (around 1.5 m). In order to improve the accuracy of the P1 solution, ionospheric corrections were estimated using the La Plata Ionospheric Model, based on the dual-frequency observations from the RESNAP-GPS network. Those corrections were applied to the RINEX files of a probing station located within the reference network. With this procedure, the vertical coordinate errors were reduced to the range from -0.8 to 0.8 m. This methodological approach shows the possibility to remarkably improve the real time positioning based on Code measurements only using ionospheric corrections estimations and CODE DCB products.

  16. Studying the recruitment of Sp1 to the ?-globin promoter with an in vivo method: Protein position identification with nuclease tail?(PIN*POINT)

    PubMed Central

    Lee, Jong-Soo; Lee, Chang-Hun; Chung, Jay H.

    1998-01-01

    Transcription is thought to be regulated by recruitment of transcription factors, adaptors, and certain enzymes to cis-acting elements through proteinDNA interactions and proteinprotein interactions. To better understand transcription, a method with the capability to detect in vivo recruitment of these individual proteins will be essential. Toward this end, we use a previously undescribed in vivo method that we term protein position identification with nuclease tail (PIN*POINT). In this method, a fusion protein composed of a chosen protein linked to a nonsequence-specific nuclease is expressed in vivo, and the binding of the protein to DNA is made detectable by the nuclease-induced cleavage near the binding site. In this article, we used the technique protein position identification with nuclease tail to study the effect of the ?-globin locus control region (LCR) and promoter elements on the recruitment of transcription factor Sp1 to the ?-globin promoter. We present evidence that the hypersensitive sites of the LCR synergistically enhance the recruitment of a multimeric Sp1 complex to the ?-globin promoter and that this may be accomplished by proteinprotein interactions with proteins bound to the LCR, the upstream activator region, and, possibly, general transcription factors bound near the TATA box. PMID:9448269

  17. In vivo reference point indentation reveals positive effects of raloxifene on mechanical properties following 6 months of treatment in skeletally mature beagle dogs.

    PubMed

    Aref, Mohammad; Gallant, Maxime A; Organ, Jason M; Wallace, Joseph M; Newman, Christopher L; Burr, David B; Brown, Drew M; Allen, Matthew R

    2013-10-01

    Raloxifene treatment has been shown previously to positively affect bone mechanical properties following 1 year of treatment in skeletally mature dogs. Reference point indentation (RPI) can be used for in vivo assessment of mechanical properties and has been shown to produce values that are highly correlated with properties derived from traditional mechanical testing. The goal of this study was to use RPI to determine if raloxifene-induced alterations in mechanical properties occurred after 6 months of treatment. Twelve skeletally mature female beagle dogs were treated for 6 months with oral doses of saline vehicle (VEH, 1 ml/kg/day) or a clinically relevant dose of raloxifene (RAL, 0.5 mg/kg/day). At 6 months, all animals underwent in vivo RPI (10N force, 10 cycles) of the anterior tibial midshaft. RPI data were analyzed using a custom MATLAB program, designed to provide cycle-by-cycle data from the RPI test and validated against the manufacturer-provided software. Indentation distance increase (IDI), a parameter that is inversely related to bone toughness, was significantly lower in RAL-treated animals compared to VEH (-16.5%), suggesting increased bone toughness. Energy absorption within the first cycle was significantly lower with RAL compared to VEH (-21%). These data build on previous work that has documented positive effects of raloxifene on material properties by showing that these changes exist after 6 months. PMID:23871851

  18. The Distribution of Cloud to Ground Lightning Strike Intensities and Associated Magnetic Inductance Fields Near the Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Burns, Lee; Decker, Ryan

    2005-01-01

    Lightning strike location and peak current are monitored operationally in the Kennedy Space Center (KSC) Cape Canaveral Air Force Station (CCAFS) area by the Cloud to Ground Lightning Surveillance System (CGLSS). The present study compiles ten years worth of CGLSS data into a database of near strikes. Using shuffle launch platform LP39A as a convenient central point, all strikes recorded within a 20-mile radius for the period of record O R ) from January 1, 1993 to December 31,2002 were included in the subset database. Histograms and cumulative probability curves are produced for both strike intensity (peak current, in kA) and the corresponding magnetic inductance fields (in A/m). Results for the full POR have application to launch operations lightning monitoring and post-strike test procedures.

  19. "Thunderstruck": penetrating thoracic injury from lightningstrike.

    PubMed

    van Waes, Oscar J F; van de Woestijne, Pieter C; Halm, Jens A

    2014-04-01

    Lightning strike victims are rarely presented at an emergency department. Burns are often the primary focus. This case report describes the improvised explosive device like-injury to the thorax due to lightning strike and its treatment, which has not been described prior in (kerauno)medicine. Penetrating injury due to blast from lightning strike is extremely rare. These "shrapnel" injuries should however be ruled out in all patients struck by lightning. PMID:24054789

  20. The 1983 direct strike lightning data, part 2

    NASA Technical Reports Server (NTRS)

    Thomas, Mitchel E.

    1985-01-01

    Data waveforms are presented which were obtained during the 1983 direct strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. Part 2 contains 443 pages of lightning strike data in chart form.

  1. THE EFFECT OF HAND DOMINANCE ON MARTIAL ARTS STRIKES

    PubMed Central

    Neto, Osmar Pinto; Silva, Jansen Henrique; de Miranda Marzullo, Ana Carolina; Bolander, Richard P.; Bir, Cynthia A.

    2011-01-01

    The main goal of this study was to compare dominant and non-dominant martial arts palm strikes under different circumstances that usually happen during martial arts and combative sports applications. Seven highly experienced (10 5 years) right hand dominant Kung Fu practitioners performed strikes with both hands, stances with left or right lead legs, and with the possibility or not of stepping towards the target (moving stance). Peak force was greater for the dominant hand strikes (1593.76 703.45 N vs. 1042.28 374.16 N; p < .001), whereas no difference was found in accuracy between the hands (p = .141). Additionally, peak force was greater for the strikes with moving stance (1448.75 686.01 N vs. 1201.80 547.98 N; p = .002) and left lead leg stance (1378.06 705.48 N vs.1269.96 547.08 N). Furthermore, the difference in peak force between strikes with moving and stationary stances was statistically significant only for the strikes performed with a left lead leg stance (p = .007). Hand speed was higher for the dominant hand strikes (5.82 1.08 m/s vs. 5.24 0.78 m/s; p = 0.001) and for the strikes with moving stance (5.79 1.01 m/s vs. 5.29 0.90 m/s; p < .001). The difference in hand speed between right and left hand strikes was only significant for strikes with moving stance. In summary, our results suggest that the stronger palm strike for a right-handed practitioner is a right hand strike on a left lead leg stance moving towards the target. PMID:22047701

  2. Debunking the viper's strike: harmless snakes kill a common assumption.

    PubMed

    Penning, David A; Sawvel, Baxter; Moon, Brad R

    2016-03-01

    To survive, organisms must avoid predation and acquire nutrients and energy. Sensory systems must correctly differentiate between potential predators and prey, and elicit behaviours that adjust distances accordingly. For snakes, strikes can serve both purposes. Vipers are thought to have the fastest strikes among snakes. However, strike performance has been measured in very few species, especially non-vipers. We measured defensive strike performance in harmless Texas ratsnakes and two species of vipers, western cottonmouths and western diamond-backed rattlesnakes, using high-speed video recordings. We show that ratsnake strike performance matches or exceeds that of vipers. In contrast with the literature over the past century, vipers do not represent the pinnacle of strike performance in snakes. Both harmless and venomous snakes can strike with very high accelerations that have two key consequences: the accelerations exceed values that can cause loss of consciousness in other animals, such as the accelerations experienced by jet pilots during extreme manoeuvres, and they make the strikes faster than the sensory and motor responses of mammalian prey and predators. Both harmless and venomous snakes can strike faster than the blink of an eye and often reach a target before it can move. PMID:26979562

  3. Risk factors associated with participation in the Ontario, Canada doctors' strike.

    PubMed Central

    Kravitz, R L; Shapiro, M F; Linn, L S; Froelicher, E S

    1989-01-01

    To identify factors associated with participation in the 1986 Ontario, Canada doctors' strike, we surveyed 1,028 physicians; 69 percent responded, of whom 42 percent participated in the strike. Risk factors for participation included income greater than $135,000, being a surgeon or gynecologist, having previously "opted out" of the Ontario Health Insurance Plan, being professionally dissatisfied, being politically conservative, favoring political activism by physicians, holding a positive view of the social consequences of extrabilling, and perceiving family, associates, patients and the public to favor the strike. Eighty percent of strikers, but 32 percent of non-strikers, met criteria we established for four strike-prone groups: the "economically rational," the "ideologically committed," the "professionally disaffected," and the "socially malleable." Respondents belonging to one or more of these groups were much more likely to have participated in the strike (64 percent vs 17 percent). Strategies to deal with physician militancy should address the multiplicity of motives that appeared to have influenced doctors in Ontario. PMID:2764198

  4. Global strike-slip fault distribution on Enceladus reveals mostly left-lateral faults

    NASA Astrophysics Data System (ADS)

    Martin, E. S.; Kattenhorn, S. A.

    2013-12-01

    Within the outer solar system, normal faults are a dominant tectonic feature; however, strike-slip faults have played a role in modifying the surfaces of many icy bodies, including Europa, Ganymede, and Enceladus. Large-scale tectonic deformation in icy shells develops in response to stresses caused by a range of mechanisms including polar wander, despinning, volume changes, orbital recession/decay, diurnal tides, and nonsynchronous rotation (NSR). Icy shells often preserve this record of tectonic deformation as patterns of fractures that can be used to identify the source of stress responsible for creating the patterns. Previously published work on Jupiter's moon Europa found that right-lateral strike-slip faults predominantly formed in the southern hemisphere and left-lateral strike-slip faults in the northern hemisphere. This pattern suggested they were formed in the past by stresses induced by diurnal tidal forcing, and were then rotated into their current longitudinal positions by NSR. We mapped the distribution of strike-slip faults on Enceladus and used kinematic indicators, including tailcracks and en echelon fractures, to determine their sense of slip. Tailcracks are secondary fractures that form as a result of concentrations of stress at the tips of slipping faults with geometric patterns dictated by the slip sense. A total of 31 strike-slip faults were identified, nine of which were right-lateral faults, all distributed in a seemingly random pattern across Enceladus's surface, in contrast to Europa. Additionally, there is a dearth of strike-slip faults within the tectonized terrains centered at 90°W and within the polar regions north and south of 60°N and 60°S, respectively. The lack of strike-slip faults in the north polar region may be explained, in part, by limited data coverage. The south polar terrain (SPT), characterized by the prominent tiger stripes and south polar dichotomy, yielded no discrete strike-slip faults. This does not suggest that the SPT is devoid of shear: previous work has indicated that the tiger stripes may be undergoing strike-slip motions and the surrounding regions may be experiencing shear. The fracture patterns and geologic activity within the SPT have been previously documented to be the result of stresses induced by both NSR and diurnal tidal deformation. As these same mechanisms are the main controls on strike-slip fault patterns on Europa, the lack of a match between strike-slip patterns on Europa and Enceladus is intriguing. The pattern of strike-slip faults on Enceladus suggests a different combination of stress mechanisms is required to produce the observed distributions. We will present models of global stress mechanisms to consider how the global-scale pattern of strike-slip faults on Enceladus may have been produced. This problem will be investigated further by measuring the angles at which tailcracks have formed on Enceladus. Tailcracks produced by simple shear form at 70.5° to the fault. Any deviation from this angle indicates some ratio of concomitant shear and dilation, which may provide insights into elucidating the stresses controlling strike-slip formation on Enceladus.

  5. Four strikes against physical mapping of DNA.

    PubMed

    Goldberg, P W; Golumbic, M C; Kaplan, H; Shamir, R

    1995-01-01

    Physical mapping is a central problem in molecular biology and the human genome project. The problem is to reconstruct the relative position of fragments of DNA along the genome from information on their pairwise overlaps. We show that four simplified models of the problem lead to NP-complete decision problems: Colored unit interval graph completion, the maximum interval (or unit interval) subgraph, the pathwidth of a bipartite graph, and the k-consecutive ones problem for k > or = 2. These models have been chosen to reflect various features typical in biological data, including false-negative and positive errors, small width of the map, and chimericism. PMID:7497116

  6. Using Grids to Teach the Skill of Striking

    ERIC Educational Resources Information Center

    Horton, Mel L.

    2006-01-01

    This article discusses the grid system as a strategy for enhancing the skill of striking in physical education. A grid system is a box or rectangle-defined space in which students practice specific skills or strategies in pairs or small groups. Here, the author provides sample activities that can be used with grids to teach striking skills for

  7. Lightning Strikes Predicted to Increase as Climate Warms

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-11-01

    By the end of the 21st century, the frequency of lightning strikes in the United States may increase by 50% because of climate warming, up from an average 25 million lightning strikes per year, a paper published in the 13 November issue of Science reports.

  8. The blowfly strike problem of sheep in New South Wales.

    PubMed

    Watts, J E; Murray, M D; Graham, N P

    1979-07-01

    A field survey was undertaken between 1972-76 to reappraise the nature of the blowfly problem in New South Wales. For 2 years, 1972-1974, some 80,000 sheep were kept under observation and 12,481 strikes were reported, most due to Lucilia cuprina. Breech strike was still the basic problem but tail strike associated with scouring had become an important component where pastures have been improved. Breech strike was controlled at minimal cost by managerial practices such as docking tails the correct length--second joint-space palpable ventrally (midway down the vulval orifice in ewes) for radically mulesed lambs and the third joint-space (tip of vulva in ewes) for all other lambs-mulesing at lamb marking, mid-season crutching, determining the cause of scouring and applying the appropriate preventative or remedial measures. Thus the use of insecticides could be reserved for the control of body strike in young sheep in the odd wet years and poll strike in horned rams. Major outbreaks of body strike occurred in 1973/74. Body strike worried graziers most because of its unpredictability, sudden onset and scale. and only failing insecticides were available for control. PMID:518435

  9. 14 CFR 25.631 - Bird strike damage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Bird strike damage. 25.631 Section 25.631... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.631 Bird strike damage. The... airplane after impact with an 8-pound bird when the velocity of the airplane (relative to the bird...

  10. Stability versus first strike costs during deep reductions

    SciTech Connect

    Canavan, G.H.

    1998-09-10

    Reducing missile forces ultimately increases stability. However, for vulnerable forces, that increase is accompanied by an increase in first strike costs, which would disincentivize force reductions. For survivable forces there is a useful region in which weapon reductions could increase stability while reducing first strike costs.

  11. 14 CFR 25.631 - Bird strike damage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird strike damage. 25.631 Section 25.631 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.631 Bird strike damage. The empennage structure must be designed...

  12. Expertise of using striking techniques for power stroke in badminton.

    PubMed

    Zhu, Qin

    2013-10-01

    Two striking techniques (fast swing and angled striking) were examined to see if they allowed effective use of string tension for the power stroke in badminton. 12 participants (4 novices, 4 recreational, and 4 expert badminton players) were recorded by a fast-speed camera while striking a shuttlecock with racquets of 8 different string tensions. The peak speed of the shuttlecock, the racquet angle and the shuttlecock angle were analyzed. The results showed that expert players succeeded in using both striking techniques to overcome the constraint of string tension and produce a consistently superior stroke. Failure to use either striking technique resulted in inferior performance that was constrained by string tension. Expertise in badminton allows the necessary motor adjustments based on the affordance perception of the string tension. PMID:24611247

  13. The earthquake cycle of strike-slip faults

    NASA Astrophysics Data System (ADS)

    Schmalzle, Gina M.

    An earthquake is a mechanism of stress release along plate boundaries due to relative motion between the Earth's lithospheric blocks. The period in which stresses are accruing across the plate boundary is known as the interseismic portion of the earthquake cycle. This dissertation focuses on interseismic portion of the earthquake cycle to extract characteristics of fault, shear zone and rock properties. Global Positioning System (GPS) data are used to observe the pattern of deformation across two primarily strike-slip fault systems: the Carrizo Segment of the San Andreas Fault (SAF) and the Eastern California Shear Zone (ECSZ). Two sets of GPS data are processed, analyzed and applied to analytic and numerical models describing the interseismic behavior of the earthquake cycle. The Carrizo segment is mature (i.e., had many earthquakes) and has juxtaposed terrains with varying rock properties laterally across the fault system. Lateral variations in rock properties affect the pattern of deformation around strike-slip faults affect how surrounding rock deforms and if not considered may bias the interpretation of the faulted system. The Carrizo segment separates Franciscan terrain northeast of the fault from Salinian block to the southwest. GPS data are well fit to a model with a 15-25 km weak zone northeast of the Carrizo segment. The long-term slip rate estimated on the SAF is 36+2-1.5 mm/yr, with 3 +/- 1 mm/yr accommodated on faults to the west. The viscosity for the combined lower crust/upper mantle is estimated at 2-5x10 19 Pa's. This model is consistent with the distribution of rock type and corresponding laboratory data on their material properties, paleoseismic, seismic and magnetotelluric data. The ECSZ is a young (<10 Myr) system of strike-slip faults including the Owens Valley - Airport Lake, Panamint Valley - Ash Hill - Hunter Mountain and Death Valley - Furnace Creek fault systems. The ECSZ study concentrates on fault evolution by finding the current position of maximum shear across the shear zone and estimating fault rates. Geologic studies suggest that the Death Valley - Furnace Creek fault system on eastern end of the ECSZ was the primary accommodator of slip early in the ECSZ history. This study suggests that the current locus of shear has shifted westward, and resides in the center of the ECSZ under the Panamint Valley - Ash Hill - Hunter Mountain fault system. The model dependent estimated geodetic rate of the Ash Hill - Panamint Valley - Hunter Mountain fault system ( 5.51+0.58-0.60 mm/yr) is faster than geologic estimates (1.6--4 mm/yr). The result is interpreted as a simplification of the ECSZ with time, combined with progressive westward migration of deformation. The best estimate for a combined rate across the shear zone is 10 mm/yr (20% of total Pacific-North America motion). The summation of rates obtained by this study is 49 mm/yr, well within estimates obtained by previous studies using independent techniques.

  14. Electromyographic Study of a Sequence of Yau-Man Kung Fu Palm Strikes with and without Impact

    PubMed Central

    Neto, Osmar Pinto; Magini, Marcio; Pacheco, Marcos T.T.

    2007-01-01

    In martial arts and contact sports, strikes are often trained in two different ways: with and without impacts. This study aims to compare the electromyographical activity (EMG) of the triceps brachii (TB), biceps brachii (BB) and brachioradialis (BR) muscles during strikes with and without impacts. Eight Yau-Man Kung Fu practitioners participated in the experiment. Each participant performed 5 sequences of 5 consecutive KF Yau-Man palm strikes with no impact intercalated with 5 sequences of 5 repetitions targeting a KF training shield. Surface EMG signals were obtained from the TB, BB, and RB for 3.0 seconds using an eight-channel module with a total amplifier gain of 2000 and sampled at 3500 Hz. The EMG analyses were done in the time (rms) and frequency (wavelet) domains. For the frequency domain, Morlet wavelet power spectra were obtained and an original method was used to quantify statistically significant regions on the power spectra. The results both in the time and frequency domains indicate a higher TB and BR muscle activity for the strikes with impacts. No significant difference was found for the BB in the two different scenarios. In addition, the results show that the wavelet power spectra pattern for the three analysed muscles obtained from the strikes with and without impacts were similar. Key points EMG analysis of a sequence of Kung Fu strikes demonstrates higher Triceps Brachii and Brachioradialis muscle activity for strikes with impact than strikes without impact. An original reliable method for quantifying EMG wavelet transform results is presented. EMG wavelet power spectra describe muscle roles during a Kung Fu sequence of strikes. PMID:24198699

  15. Electromyographic Study of a Sequence of Yau-Man Kung Fu Palm Strikes with and without Impact.

    PubMed

    Neto, Osmar Pinto; Magini, Marcio; Pacheco, Marcos T T

    2007-01-01

    IN MARTIAL ARTS AND CONTACT SPORTS, STRIKES ARE OFTEN TRAINED IN TWO DIFFERENT WAYS: with and without impacts. This study aims to compare the electromyographical activity (EMG) of the triceps brachii (TB), biceps brachii (BB) and brachioradialis (BR) muscles during strikes with and without impacts. Eight Yau-Man Kung Fu practitioners participated in the experiment. Each participant performed 5 sequences of 5 consecutive KF Yau-Man palm strikes with no impact intercalated with 5 sequences of 5 repetitions targeting a KF training shield. Surface EMG signals were obtained from the TB, BB, and RB for 3.0 seconds using an eight-channel module with a total amplifier gain of 2000 and sampled at 3500 Hz. The EMG analyses were done in the time (rms) and frequency (wavelet) domains. For the frequency domain, Morlet wavelet power spectra were obtained and an original method was used to quantify statistically significant regions on the power spectra. The results both in the time and frequency domains indicate a higher TB and BR muscle activity for the strikes with impacts. No significant difference was found for the BB in the two different scenarios. In addition, the results show that the wavelet power spectra pattern for the three analysed muscles obtained from the strikes with and without impacts were similar. Key pointsEMG analysis of a sequence of Kung Fu strikes demonstrates higher Triceps Brachii and Brachioradialis muscle activity for strikes with impact than strikes without impact.An original reliable method for quantifying EMG wavelet transform results is presented.EMG wavelet power spectra describe muscle roles during a Kung Fu sequence of strikes. PMID:24198699

  16. San Andreas-sized Strike-slip Fault on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This mosaic of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, about the size of the California portion of the San Andreas fault, which runs from the California-Mexico border north to the San Francisco Bay.

    In a strike-slip fault, two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. Overall motion along the fault seems to have followed a continuous narrow crack along the feature's entire length, with a path resembling steps on a staircase crossing zones that have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. The fault's opposite sides can be reconstructed like a puzzle, matching the shape of the sides and older, individual cracks and ridges broken by its movements.

    [figure removed for brevity, see original site]

    The red line marks the once active central crack of the fault. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart.

    Bends in the fault have allowed the surface to be pulled apart. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above.

    One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. Tidal tension opens the fault and subsequent tidal stress causes it to move lengthwise in one direction. Then tidal forces close the fault again, preventing the area from moving back to its original position. Daily tidal cycles produce a steady accumulation of lengthwise offset motions. Here on Earth, unlike Europa, large strike-slip faults like the San Andreas are set in motion by plate tectonic forces.

    North is to the top of the picture and the sun illuminates the surface from the top. The image, centered at 66 degrees south latitude and 195 degrees west longitude, covers an area approximately 300 by 203 kilometers(185 by 125 miles). The pictures were taken on September 26, 1998by Galileo's solid-state imaging system.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  17. Pathognomonic symptom associated with lightning strike: Lichtenberg figure.

    PubMed

    Yigit, Mehmet; Tanrikulu, Nazmiye; Turkdogan, Kenan Ahmet; Yigit, Eda

    2015-02-01

    Lightning strikes especially occur during spring and summer months in the afternoons when there is heavy rain. In deaths resulting from lightning strike, there may either be no evidence on the dead person's clothes or body, or there may be burnt or torn patches on their clothes and lichtenberg figures specific to lightning strikes on their bodies. In such cases that also have a comorbid of cognitive dysfunction, since there is generally amnesia, having these figures during the physical examination has a valuable place in early diagnosis and quick treatment. This paper presents a case of lightning strike that was found to have Lichtenberg figures on the back and right leg after secondary examination. PMID:25842563

  18. Measurements of lightning rod responses to nearby strikes

    NASA Astrophysics Data System (ADS)

    Moore, C. B.; Aulich, G. D.; Rison, W.

    2000-05-01

    Following Benjamin Franklin's invention of the lightning rod, based on his discovery that electrified objects could be discharged by approaching them with a metal needle in hand, conventional lightning rods in the U.S. have had sharp tips. In recent years, the role of the sharp tip in causing a lightning rod to act as a strike receptor has been questioned leading to experiments in which pairs of various sharp-tipped and blunt rods have been exposed beneath thunderclouds to determine the better strike receptor. After seven years of tests, none of the sharp Franklin rods or of the so-called early streamer emitters has been struck, but 12 blunt rods with tip diameters ranging from 12.7 mm to 25.4 mm have taken strikes. Our field experiments and our analyses indicate that the strike-reception probabilities of Franklin's rods are greatly increased when their tips are made moderately blunt.

  19. Conditions for lightning strikes to an airplane in a thunderstorm

    NASA Technical Reports Server (NTRS)

    Mazur, V.; Fisher, B. D.; Gerlach, J. C.

    1984-01-01

    Conditions conducive to lightning strikes on aircraft were determined through the 1982 Storm Hazards Program. UHF-radar and SPANDAR were used to guide a NASA F-106B research aircraft through the upper regions of active thunderstorms to facilitate direct lightning strikes to the aircraft. Analysis of radar echoes from lightning at the moments of the strikes suggests that the aircraft itself triggers the lightning, in both stormy and nonstormy clouds, and that the induced flashes are not much different from naturally occurring intra-cloud flashes. The highest risk for a direct strike in the upper portions of a thunderstorm occurred where the ambient temperature was -40 C or colder, where turbulence and precipitation were negligible to light, and where the lightning flash rate was no greater than 5 flashes per minute.

  20. Student Involvement in and Information about a University Strike

    ERIC Educational Resources Information Center

    Jensen, Robert G.; Marcuse, F. L.

    1972-01-01

    The present study was directed toward studying the relationship for male and female students between participation in a collective social action and the amount of information they possessed about that action-in this instance a university strike. (Author)

  1. The 1985 and 1986 direct strike lightning data, part 2

    NASA Technical Reports Server (NTRS)

    Zaepfel, Klaus P.; Carney, Harold K.

    1988-01-01

    Data waveforms are presented which were obtained during the 1985 and 1986 direct-strike lightning tests utilizing the NASA F-106B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was flown in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment in order to elicit lightning strikes. Electromagnetic field data and conduction currents on the aircraft were recoded for lightning.

  2. The 1985 and 1986 direct strike lightning data, part 1

    NASA Technical Reports Server (NTRS)

    Zaepfel, Klaus P.; Carney, Harold K.

    1988-01-01

    Data waveforms are presented which were obtained during the 1985 and 1986 direct-strike lightning tests utilizing the NASA F-106B aircraft specially instrumented for lightning electromagnetic measurement. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment in order to elicit lightning strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for lightning.

  3. The 1984 direct strike lightning data, part 3

    NASA Technical Reports Server (NTRS)

    Thomas, Mitchel E.; Carney, Harold K.

    1986-01-01

    Data waveforms are presented which were obtained during the 1984 direct-strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. This is part 3, consisting entirely of charts and graphs.

  4. The 1984 direct strike lightning data, part 2

    NASA Technical Reports Server (NTRS)

    Thomas, Mitchel E.; Carney, Harold K.

    1986-01-01

    Data waveforms are presented which were obtained during the 1984 direct-strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. This is part 2, consisting entirely of charts and graphs.

  5. Optimization of stability index versus first strike cost

    SciTech Connect

    Canavan, G.H.

    1997-05-01

    This note studies the impact of maximizing the stability index rather than minimizing the first strike cost in choosing offensive missile allocations. It does so in the context of a model in which exchanges between vulnerable missile forces are modeled probabilistically, converted into first and second strike costs through approximations to the value target sets at risk, and the stability index is taken to be their ratio. The value of the allocation that minimizes the first strike cost for both attack preferences are derived analytically. The former recovers results derived earlier. The latter leads to an optimum at unity allocation for which the stability index is determined analytically. For values of the attack preference greater than about unity, maximizing the stability index increases the cost of striking first 10--15%. For smaller values of the attack preference, maximizing the index increases the second strike cost a similar amount. Both are stabilizing, so if both sides could be trusted to target on missiles in order to minimize damage to value and maximize stability, the stability index for vulnerable missiles could be increased by about 15%. However, that would increase the cost to the first striker by about 15%. It is unclear why--having decided to strike--he would do so in a way that would increase damage to himself.

  6. Infiltration from a surface point source and drip irrigation: 2. An approximate time-dependent solution for wet-front position

    NASA Astrophysics Data System (ADS)

    Revol, P.; Clothier, B. E.; Mailhol, J.-C.; Vachaud, G.; Vauclin, M.

    1997-08-01

    Raats' [1971] steady state theory is here extended to provide an approximate analysis of the transient pattern of wetting around a point source. The assumption that a steady state regime prevails behind the wet front and the use of the Clothier [1984] and Philip [1984] theories on water movement along the streamlines allows an approximate transient solution for surface point source infiltration to be developed. This procedure was previously tested against absorption theory and laboratory experiments [Revol et al., 1995], but now this new analysis is evaluated via a field test. The vertical elongating influence of gravity is found to be well predicted. Application of this analysis to design purposes is also mentioned. The role of the macroscopic characteristic capillary length of unsaturated flow, ?c, is highlighted by this approximate solution. Finally, we propose a method that allows estimation of ?c from a point-source infiltration experiment.

  7. Positive Changes in Perceptions and Selections of Healthful Foods by College Students after a Short-Term Point-of-Selection Intervention at a Dining Hall

    ERIC Educational Resources Information Center

    Peterson, Sharon; Duncan, Diana Poovey; Null, Dawn Bloyd; Roth, Sara Long; Gill, Lynn

    2010-01-01

    Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students' perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18-23) completed pre-I and post-I surveys.

  8. Positive Changes in Perceptions and Selections of Healthful Foods by College Students after a Short-Term Point-of-Selection Intervention at a Dining Hall

    ERIC Educational Resources Information Center

    Peterson, Sharon; Duncan, Diana Poovey; Null, Dawn Bloyd; Roth, Sara Long; Gill, Lynn

    2010-01-01

    Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students' perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18-23) completed pre-I and post-I surveys.…

  9. Application of converted-wave amplitude for fracture strike delineation - a physical model study

    NASA Astrophysics Data System (ADS)

    Chang, Chih-Hsiung; Chang, Young-Fo Chang; Tseng, Po-Yen; Lin, Chao-Ming

    2013-04-01

    The objective of this study is aiming on directing the fracture strike in a vertically aligned fracture reservoir using the seismic signature of the azimuthal dependence of C-wave amplitude (ADCA). A fractured reservoir has made itself as one of the most important productive zones in petroleum exploration. The existence of fractures not just provides the space for the residence of oils and gases but creates pathways for migration. In terms of seismic anisotropy, reservoirs that possess vertical fractures system (VFS) has its physical properties vary in azimuth and is often grouped as a horizontally transversely isotropy (HTI). Since fracture strike is the priori information in drilling engineering that has to be known to maximize production or to enhance oil recovery (EOR) from a VFS reservoir. Therefore, characterizing a fractured reservoir and orienting the fracture strike has attracted much attention by exploration geophysicists and drilling engineers. To validate our objective, a HTI model was designed to simulate a VFS reservoir. A spherical dome was caved at one side of the HTI model. In laboratory, a pair of S-type transducer was used to carry out our reflection experiments. And constant offset reflections were acquired along principal symmetry directions and diagonal direction of the HTI model at two different offset intervals. In all, two constant offset reflection data sets were obtained and each data set consists of three observations collected at different azimuths. In the acquired seismic profile, a mixture of P-wave, S-wave and C-wave events were recognized. In analyzing the variation of C-wave amplitude in azimuth in the HTI model, reflections that were originated from apex of the dome structure were sorted and displayed as a common-reflection-point (CRP) gather. Our laboratory data show C-wave amplitude decrease with azimuth varying from a strike direction toward a direction transverse to the strike in the HTI model. The phenomenon of ADCA that was demonstrated can be considered as a valuable seismic attribute to orient the fracture strike in a VFS reservoir. For C-wave comes from a mode conversion of P- and S-waves, it takes behavior of P- and S-waves, and can be acquired using multi-component seismic recording survey. In conjunction with the azimuthal velocity and amplitude variations of P-wave and azimuthal polarization of S-wave, our experimental results not just provide a prospect to explore fracture strike but confident the characterization a fractured reservoir using multi-component 3D seismic data.

  10. Numerical Assessment of the Diagnostic Capabilities of the Instrumented Calorimeter for SPIDER (STRIKE)

    SciTech Connect

    Dalla Palma, M.; Pasqualotto, R.; Rizzolo, A.; Serianni, G.; Veltri, P.; De Muri, M.

    2011-09-26

    An important feature of the ITER project is represented by additional heating via injection of neutral beams from accelerated negative ions. To study and optimise their production, the SPIDER test facility is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation.STRIKE (Short-Time Retractable Instrumented Kalorimeter Experiment) is a diagnostic to characterise the SPIDER negative ion beam during short operation (several seconds). During long pulse operations, STRIKE is parked off-beam in the vacuum vessel. The most important measurements are beam uniformity, beamlet divergence and stripping losses. STRIKE is directly exposed to the beam and is formed of 16 tiles, one for each beamlet groups. The measurements are provided by thermal cameras, current sensors, thermocouples and electrostatic sensors. This paper presents the investigation of the influence on the response of STRIKE of: thermal characteristics of the tile material, exposure angle, features of some dedicated diagnostics. The uniformity of the beam will be studied by measurements of the current flowing through each tile and by thermal cameras. Simulations show that it will be possible to verify experimentally whether the beam meets the ITER requirement about the maximum allowed beam non-uniformity (below {+-}10%). In the simulations also the influence of the beam halo has been included; the effect of off-perveance conditions has been studied. To estimate the beamlet divergence, STRIKE can be moved along the beam direction at two different distances from the accelerator. The optimal positions have been defined taking into account design constraints. The effect of stripping on the comparison between currents and heat loads has been assessed; this will allow to obtain an experimental estimate of stripping. Electrostatic simulations have provided the suitable tile biasing voltage in order to reabsorb secondary particles into the same tile as the one where they were emitted from.

  11. Simulation and measurement of melting effects on metal sheets caused by direct lightning strikes

    NASA Technical Reports Server (NTRS)

    Kern, Alexander

    1991-01-01

    Direct lightning strikes melt metal parts of various systems, like fuel and propellant tanks of rockets and airplanes, at the point of strike. Responsible for this melting are the impulse current and, if occurring, the long duration current, both carrying a remarkable charge Q. For studying these meltings the simulation in the laboratory has to be based on the parameters of natural lightnings. International standards exist defining certain threat levels of natural lightnings and giving possible generator circuits for the simulation. The melting caused by both types of lightning currents show different appearance. Their characteristics, their differences in melting and heating of metal sheets are investigated. Nevertheless the simulation of lightning in the laboratory is imperfect. While natural lightning is a discharge without a counter electrode, the simulation always demands a close counter electrode. The influence of this counter electrode is studied.

  12. A three-dimensional viscoelastic model of a strike slip fault

    NASA Technical Reports Server (NTRS)

    Rundle, J. B.; Jackson, D. D.

    1975-01-01

    An analytic approximation to the Green's function for the displacements due to a strike slip point source in an elastic layer over a viscoelastic half-space is developed. This approximate Green's function is useful because it can be analytically integrated over the fault surface. Comparison with a numerical integration of the exact solution integral indicates that the approximation is quite good. The approximate Green's function is integrated analytically to obtain the displacements due to a finite rectangular strike slip fault in an elastic layer over a viscoelastic half-space. Ground displacements and angle changes from a model survey net are computed to illustrate the viscoelastic relaxation which follows a fracture in the elastic region.

  13. Extremely rare coincidence of non-radiographic axial spondyloarthropathy HLA-B27 positive and Stiff Person Syndrome - rheumatologist point of view.

    PubMed

    Marinovi?, Ivanka; Pivalica, Dinko; Aljinovi?, Jure; Vlak, Tonko; kori?, Ela; Martinovi? Kaliterna, Duanka

    2016-03-01

    Stiff Person Syndrome (SPS) is a rare autoimmune neurological disorder characterized by progressive stiffness and rigidity of truncal muscles accompanied with co-contraction of agonist-antagonist muscles. Our 51-year-old female patient was presented for the first time to physiatrists in 2006 and diagnosed with axial-spondyloarthropathy (SpA) HLA-B27 positive. SPS was diagnosed 7 years after initial symptoms. SPS should be taken into consideration in HLA-B27 positive patients if stiffness of paravertebral and abdominal muscles progresses during SpA therapy. PMID:24289195

  14. Enhanced resistive switching phenomena using low-positive-voltage format and self-compliance IrOx/GdOx/W cross-point memories

    PubMed Central

    2014-01-01

    Enhanced resistive switching phenomena of IrOx/GdOx/W cross-point memory devices have been observed as compared to the via-hole devices. The as-deposited Gd2O3 films with a thickness of approximately 15 nm show polycrystalline that is observed using high-resolution transmission electron microscope. Via-hole memory device shows bipolar resistive switching phenomena with a large formation voltage of -6.4 V and high operation current of >1 mA, while the cross-point memory device shows also bipolar resistive switching with low-voltage format of +2 V and self-compliance operation current of <300 μA. Switching mechanism is based on the formation and rupture of conducting filament at the IrOx/GdOx interface, owing to oxygen ion migration. The oxygen-rich GdOx layer formation at the IrOx/GdOx interface will also help control the resistive switching characteristics. This cross-point memory device has also Repeatable 100 DC switching cycles, narrow distribution of LRS/HRS, excellent pulse endurance of >10,000 in every cycle, and good data retention of >104 s. This memory device has great potential for future nanoscale high-density non-volatile memory applications. PMID:24400888

  15. Isolated Sensorineural Hearing Loss as a Sequela after Lightning Strike.

    PubMed

    Turan, Mahfuz; Kalkan, Ferhat; Bozan, Nazım; Özçalimli, İsa; Zeki Erdem, Mehmet; Yalınkılıç, Abdülaziz; Garca, Mehmet Fatih

    2015-01-01

    In most of the surviving patients after a lightning strike, audiovestibular abnormalities have been reported. The most frequently reported type of abnormalities is a tympanic membrane perforation with hearing loss and external ear canal burn. However a sensor neural hearing loss and mixed type hearing loss can also occur, but these occur rarely. A nineteen-year-old female patient had, after a lightning strike, serious burns on the left ear, behind the ear, and on the chest and neck. She also had in her left ear 108 dB hearing loss with irregular central perforation and in her right ear 52 dB sensorineural hearing loss. There was no hearing loss before the strike. A hearing aid was recommended for the right ear and good care and follow-up were recommended for the left ear. A lightning strike can cause serious audiological damage. Therefore, it is necessary to make a careful audiovestibular evaluation of the patients. Although there exist rarely healed cases from sensorineural hearing loss after lightning strike in literature, in our case hearing loss occurred bilaterally and then it healed unilaterally. This condition is quite rare in literature. PMID:26161278

  16. Global Morphological Mapping of Strike-Slip Structures on Ganymede

    NASA Astrophysics Data System (ADS)

    Smith-Konter, B. R.; Cameron, M. E.; Seifert, F.; Pappalardo, R. T.; Collins, G. C.

    2014-12-01

    Many inferences of strike-slip faulting and distributed shear zones on Ganymede suggest that strike-slip tectonism may be important to the structural development of its surface and in the transition from dark to light (grooved) materials. To better understand the role of strike-slip tectonism in shaping Ganymede's multifaceted surface, we identify and map key examples of strike-slip morphologies (en echelon structures, strike-slip duplexes, laterally offset pre-existing features, and possible strained craters) from Galileo and Voyager images. Here we present the current state of these global mapping efforts, with particular emphasis given to complex structures associated with grooved terrain (e.g. Nun Sulci) and terrains transitional from dark to light terrain (e.g. the boundary between Nippur Sulcus and Marius Regio). These results are being synthesized into a global database representing an inferred sense of shear for fractures on Ganymede. This, combined with existing observations of extensional features, is helping to narrow down the range of possible principal stress directions that could have acted at the regional or global scale to produce grooved terrain. Moreover, these data sets, combined with mechanical models of shear failure and global stress sources, are providing constraints for testing possible mechanisms for grooved terrain formation on Ganymede.

  17. Isolated Sensorineural Hearing Loss as a Sequela after Lightning Strike

    PubMed Central

    Turan, Mahfuz; Kalkan, Ferhat; Bozan, Naz?m; zalimli, ?sa; Zeki Erdem, Mehmet; Yal?nk?l?, Abdlaziz; Garca, Mehmet Fatih

    2015-01-01

    In most of the surviving patients after a lightning strike, audiovestibular abnormalities have been reported. The most frequently reported type of abnormalities is a tympanic membrane perforation with hearing loss and external ear canal burn. However a sensor neural hearing loss and mixed type hearing loss can also occur, but these occur rarely. A nineteen-year-old female patient had, after a lightning strike, serious burns on the left ear, behind the ear, and on the chest and neck. She also had in her left ear 108?dB hearing loss with irregular central perforation and in her right ear 52?dB sensorineural hearing loss. There was no hearing loss before the strike. A hearing aid was recommended for the right ear and good care and follow-up were recommended for the left ear. A lightning strike can cause serious audiological damage. Therefore, it is necessary to make a careful audiovestibular evaluation of the patients. Although there exist rarely healed cases from sensorineural hearing loss after lightning strike in literature, in our case hearing loss occurred bilaterally and then it healed unilaterally. This condition is quite rare in literature. PMID:26161278

  18. Is There Evidence to Support a Forefoot Strike Pattern in Barefoot Runners? A Review

    PubMed Central

    Lorenz, Daniel S.; Pontillo, Marisa

    2012-01-01

    Context: Barefoot running is a trend among running enthusiasts that is the subject of much controversy. At this time, benefits appear to be more speculative and anecdotal than evidence based. Additionally, the risk of injuries is not well established. Evidence acquisition: A PubMed search was undertaken for articles published in English from 1980 to 2011. Additional references were accrued from reference lists of research articles. Results: While minimal data exist that definitively support barefoot running, there are data lending support to the argument that runners should use a forefoot strike pattern in lieu of a heel strike pattern to reduce ground reaction forces, ground contact time, and step length. Conclusions: Whether there is a positive or negative effect on injury has yet to be determined. Unquestionably, more research is needed before definitive conclusions can be drawn. PMID:24179586

  19. The Position of Proximal Reference Point of Tibia Plateau for Correct Tibial Osteotomy in Total Knee Replacement: Prospective Randomized and 6 Years Follow-up Study

    PubMed Central

    Chae, Woo Young

    2011-01-01

    Purpose When there is a varus deformity in proximal tibia, the extension of a tibial shaft axis tends to pass through the lateral intercondylar eminence. A prospective randomized study was conducted to find out whether the lateral eminence of tibia could serve as a reference point for proximal tibial osteotomy during total knee arthroplasty and results from 6-years follow up period were reported. Materials and Methods Forty-six patients (50 knees) who received total knee replacement arthroplasty from April to December 2004, were randomly divided into two groups. For a proximal tibial osteotomy, the proximal tibial reference point was located at the center of intercondylar eminence for group I and at the lateral eminence for group II and subsequently, the results were evaluated. Radiologic indices were the angles between the axis of the prosthesis and the mechanical/shaft axes of tibia and angle of the prosthesis in sagittal plane. Clinical indices were pain and function score of American knee society, functional score of Hospital for Special Surgery and range of knee joint motion. Results The angles between the axis of the prostheses and the mechanical/shaft axes of tibia were varus 1.64°/2.12° in group I and valgus 0.57°/0.38° in group II (p=0.589/p=0.558). There were 6 cases of outliers (27.2%) in group 1 and 3 cases (15.0%) in group 2. There was a significant difference in the pain score between group I (82.9) and II (91.4) (p=0.032), respectively. Conclusions By moving the reference point of proximal tibial osteotomy laterally, lower incidence of outlier and residual varus deformity could be achieved. PMID:22570834

  20. Rearward movement of the heel at heel strike.

    PubMed

    McGorry, Raymond W; Chang, Chien-Chi; DiDomenico, Angela

    2008-11-01

    This paper describes the observation of rearward movement (RM) of the heel following heel strike occurring during normal gait. Thirty-one participants recruited as part of a larger study on slip kinematics walked the length of an 8-m runway at a speed of 1.5 m/s. Several floor surfaces, presented dry and with contaminant, were used for the purpose of eliciting a wide range of small slip distances. The normal force applied to a forceplate mounted in the runway was used to identify heel strike, as well as to calculate the utilized coefficient of friction during early stance phase. A motion analysis system tracked the displacement of two heel-mounted markers, and the data were used to derive kinematic variables related to the heel strike event. Results showed that RMs occurred in 18.1% of 494 trials, with a mean rearward displacement of 5.02 (+/-3.68) mm. When present, RMs occurred in close temporal proximity to heel strike, typically completing RM within 40 ms of the heel strike event. When divided into groups by age, older participants (>40 years) were more than twice as likely to have RMs as younger participants. When grouped by height or weight, differences in the proportion of trials with RMs were small. In trials where RMs were observed, forward slip distances were significantly less than for trials with no RMs, 2.17 (+/-3.87) mm vs. 12.58 (+/-10.71) mm, respectively. The time until the heel stopped moving during the post-heel strike period was not significantly different between RM and non-RM trials. Further investigation of this gait feature may improve understanding of normal gait patterns and may have implications for future slipmeter development. PMID:18280459

  1. Comparison of blade-strike modeling results with empirical data

    SciTech Connect

    Ploskey, Gene R.; Carlson, Thomas J.

    2004-03-01

    This study is the initial stage of further investigation into the dynamics of injury to fish during passage through a turbine runner. As part of the study, Pacific Northwest National Laboratory (PNNL) estimated the probability of blade strike, and associated injury, as a function of fish length and turbine operating geometry at two adjacent turbines in Powerhouse 1 of Bonneville Dam. Units 5 and 6 had identical intakes, stay vanes, wicket gates, and draft tubes, but Unit 6 had a new runner and curved discharge ring to minimize gaps between the runner hub and blades and between the blade tips and discharge ring. We used a mathematical model to predict blade strike associated with two Kaplan turbines and compared results with empirical data from biological tests conducted in 1999 and 2000. Blade-strike models take into consideration the geometry of the turbine blades and discharges as well as fish length, orientation, and distribution along the runner. The first phase of this study included a sensitivity analysis to consider the effects of difference in geometry and operations between families of turbines on the strike probability response surface. The analysis revealed that the orientation of fish relative to the leading edge of a runner blade and the location that fish pass along the blade between the hub and blade tip are critical uncertainties in blade-strike models. Over a range of discharges, the average prediction of injury from blade strike was two to five times higher than average empirical estimates of visible injury from shear and mechanical devices. Empirical estimates of mortality may be better metrics for comparison to predicted injury rates than other injury measures for fish passing at mid-blade and blade-tip locations.

  2. Dynamic Ridges and Valleys in a Strike-Slip Environment

    NASA Astrophysics Data System (ADS)

    Duvall, Alison R.; Tucker, Gregory E.

    2015-10-01

    Strike-slip faults have long been known for characteristic near-fault landforms such as offset rivers and strike-parallel valleys. In this study, we use a landscape evolution model to investigate the longer-term, catchment-wide landscape response to horizontal fault motion. Our results show that strike-slip faulting induces a persistent state of disequilibrium in the modeled landscapes brought about by river lengthening along the fault alternating with abrupt shortening due to stream capture. The models also predict that, in some cases, ridges oriented perpendicular to the fault migrate laterally in conjunction with fault motion. We find that ridge migration happens when slip rate is slow enough and/or soil creep and river incision are efficient enough that the landscape can respond to the disequilibrium brought about by strike-slip motion. Regional rock uplift relative to baselevel also plays a role, as topographic relief is required for ridge migration. In models with faster horizontal slip rates, stronger rocks, or less efficient hillslope transport, ridge mobility is limited or arrested despite the continuance of river lengthening and capture. In these cases, prominent steep, fault-facing facets form along well-developed fault valleys. Comparison of landscapes adjacent to fast-slipping (>30 mm/yr) and slower-slipping (≤1 mm/yr or less) strike-slip faults in California, USA, reveals features that are consistent with model predictions. Our results highlight a potential suite of geomorphic signatures that can be used as indicators of horizontal crustal motion and geomorphic processes in strike-slip settings even after river capture has diminished or erased apparent offset along the fault.

  3. Determining the probability of lightning striking the Device Assembly Facility

    SciTech Connect

    Hasbrouck, R.T.

    1996-06-07

    The likelihood of lightning striking a new facility at the Nevada Test Site (NTS) has been considered in conjunction with a Lightning Hazard Mitigation study for that facility. Probability was estimated using both an older {open_quotes}traditional{close_quotes} method and a new method in which five years of actual NTS lightning strike data was analyzed. We believe the new method provides a more credible estimate. An important finding is that the NTS data exhibits a distribution of return-stroke peak-current amplitudes that is significantly less severe than that generally used by the lightning protection community, or found in other parts of the United States.

  4. The 1984 direct strike lightning data, part 1

    NASA Technical Reports Server (NTRS)

    Thomas, Mitchel E.; Carney, Harold K.

    1986-01-01

    Data waveforms are presented which were obtained during the 1984 direct-strike lightning tests utilizing the NASA F106-B aircraft specially instrumented for lightning electromagnetic measurements. The aircraft was operated in the vicinity of the NASA Langley Research Center, Hampton, Virginia, in a thunderstorm environment to elicit strikes. Electromagnetic field data and conduction currents on the aircraft were recorded for attached lightning. The entire transient recorder data obtained for 247 uses and 11 nearby flashes in the 1984 campaign are presented. This is part 1, consisting of summary and conclusion.

  5. A Preclinical Model for ERα-Positive Breast Cancer Points to the Epithelial Microenvironment as Determinant of Luminal Phenotype and Hormone Response.

    PubMed

    Sflomos, George; Dormoy, Valerian; Metsalu, Tauno; Jeitziner, Rachel; Battista, Laura; Scabia, Valentina; Raffoul, Wassim; Delaloye, Jean-Francois; Treboux, Assya; Fiche, Maryse; Vilo, Jaak; Ayyanan, Ayyakkannu; Brisken, Cathrin

    2016-03-14

    Seventy-five percent of breast cancers are estrogen receptor α positive (ER(+)). Research on these tumors is hampered by lack of adequate in vivo models; cell line xenografts require non-physiological hormone supplements, and patient-derived xenografts (PDXs) are hard to establish. We show that the traditional grafting of ER(+) tumor cells into mammary fat pads induces TGFβ/SLUG signaling and basal differentiation when they require low SLUG levels to grow in vivo. Grafting into the milk ducts suppresses SLUG; ER(+) tumor cells develop, like their clinical counterparts, in the presence of physiological hormone levels. Intraductal ER(+) PDXs are retransplantable, predictive, and appear genomically stable. The model provides opportunities for translational research and the study of physiologically relevant hormone action in breast carcinogenesis. PMID:26947176

  6. When the Corporate Storm Strikes the Academy: Faculty Response Required

    ERIC Educational Resources Information Center

    DeBoy, James L.

    2015-01-01

    When the corporate storm strikes the academy, faculty must be willing and able to repel administrative assaults upon academic freedom, shared governance, and tenure. This paper will describe the on-going clash between administrators who embrace the corporate mindset and faculty who cherish traditions of shared governance and collegial

  7. STS-135 Launch Pad Lightning Strike - Duration: 7 seconds.

    NASA Video Gallery

    A pair of lightning strikes occurred near launch pad 39-A at NASA's Kennedy Space Center at 12:31 p.m. and 12:40 p.m. EDT on July 7. The first struck the water tower 515 feet from the pad and the s...

  8. Torts Liability for Strike Action and Third Party Rights.

    ERIC Educational Resources Information Center

    Raday, Frances

    1979-01-01

    Studies the nature of the torts liability incurred in strikes and the extent of existing immunities bestowed on strikers and their organizers, and explores the principles that should govern liability and immunity. Available from Israel Law Review Association, c/o Faculty of Law, Hebrew University of Jerusalem, Mount Scopus, P.O.B. 24100, Jerusalem

  9. Lightning-Strike Disaster: Effects on Children's Fears and Worries.

    ERIC Educational Resources Information Center

    Dollinger, Stephen J.; And Others

    1984-01-01

    Compares fears of lightning-strike victims (N=29) with matched control children (N=58), using fear reports from children and their mothers. Differences between samples were most pronounced for child-reported fears. Correspondence between mothers' and children's reports of intense storm-related fears was markedly larger in the lightning sample than

  10. Monte Carlo Simulation to Estimate Likelihood of Direct Lightning Strikes

    NASA Technical Reports Server (NTRS)

    Mata, Carlos; Medelius, Pedro

    2008-01-01

    A software tool has been designed to quantify the lightning exposure at launch sites of the stack at the pads under different configurations. In order to predict lightning strikes to generic structures, this model uses leaders whose origins (in the x-y plane) are obtained from a 2D random, normal distribution.

  11. Introduction: Mapping Teachers' Strikes--A "Professionalist" Approach

    ERIC Educational Resources Information Center

    Robert, Andre D.; Tyssens, Jeffrey

    2008-01-01

    This article aims to interpret teacher strikes through a multi-level analysis and the identification of a number of relevant factors relative to the professional project (in a neo-Weberian sense) of primary and secondary school teachers. In the first place the authors' interpretation is based on references to contextual and structural elements,

  12. Student Strike: An Educational Career Decision for Student Teachers.

    ERIC Educational Resources Information Center

    Hull, Ronald E.; Driscoll, Robert L.

    This study was conducted primarily to provide feedback to the professional staff about the student strike of May 1970 and its implications for the student teaching program. It examined the following questions: 1) What general factors were considered important in making a career decision brought about by social unrest? 2) What was the rationale on

  13. Formation and Suppression of Strike-Slip Fault Systems

    NASA Astrophysics Data System (ADS)

    Curren, Ivy S.; Bird, Peter

    2014-11-01

    Strike-slip faults are a defining feature of plate tectonics, yet many aspects of their development and evolution remain unresolved. For intact materials and/or regions, a standard sequence of shear development is predicted from physical models and field studies, commencing with the formation of Riedel shears and culminating with the development of a throughgoing fault. However, for materials and/or regions that contain crustal heterogeneities (normal and/or thrust faults, joints, etc.) that predate shear deformation, kinematic evolution of strike-slip faulting is poorly constrained. We present a new plane-stress finite-strain physical analog model developed to investigate primary deformation zone evolution in simple shear, pure strike-slip fault systems in which faults or joints are present before shear initiation. Experimental results suggest that preexisting mechanical discontinuities (faults and/or joints) have a marked effect on the geometry of such systems, causing deflection, lateral distribution, and suppression of shears. A lower limit is placed on shear offset necessary to produce a throughgoing fault in systems containing preexisting structures. Fault zone development observed in these experiments provides new insight for kinematic interpretation of structural data from strike-slip fault zones on Earth, Venus, and other terrestrial bodies.

  14. Lightning-Strike Disaster: Effects on Children's Fears and Worries.

    ERIC Educational Resources Information Center

    Dollinger, Stephen J.; And Others

    1984-01-01

    Compares fears of lightning-strike victims (N=29) with matched control children (N=58), using fear reports from children and their mothers. Differences between samples were most pronounced for child-reported fears. Correspondence between mothers' and children's reports of intense storm-related fears was markedly larger in the lightning sample than…

  15. Topic 101: Eleven Campuses, One University, Many Strikes

    ERIC Educational Resources Information Center

    Navarro-Rivera, Pablo

    2010-01-01

    Students from the University of Puerto Rico (UPR) went on strike in April, and, soon after, 10 of the 11 campuses of a public system with more than 60,000 students were closed. "Once recintos, una universidad" (eleven campuses, one university) was the maxim students used to emphasize the concept of the UPR as a system unified by similar goals,

  16. Introduction: Mapping Teachers' Strikes--A "Professionalist" Approach

    ERIC Educational Resources Information Center

    Robert, Andre D.; Tyssens, Jeffrey

    2008-01-01

    This article aims to interpret teacher strikes through a multi-level analysis and the identification of a number of relevant factors relative to the professional project (in a neo-Weberian sense) of primary and secondary school teachers. In the first place the authors' interpretation is based on references to contextual and structural elements,…

  17. What To Do When Contagious Disease Strikes Your School.

    ERIC Educational Resources Information Center

    American Bar Association, Chicago, IL.

    This publication presents 10 documents collected to accompany a seminar entitled "What To Do When Contagious Disease Strikes Your School," presented at the 31st annual convention of the National Organization on Legal Problems of Education in 1985. The materials include (1) an agenda of the seminar listing the speakers, their topics, and the time

  18. Using Primary Sources To Teach the Rail Strike of 1877.

    ERIC Educational Resources Information Center

    Lesh, Bruce

    1999-01-01

    Describes a lesson plan that utilizes two primary sources, a handbill announcing the reduction in Baltimore and Ohio rail workers' wages and a list of damages to Baltimore and Ohio Railroad property, in order to determine the causes and effects of the Rail Strike of 1877. Provides the two sources and other handouts. (CMK)

  19. What To Do When Contagious Disease Strikes Your School.

    ERIC Educational Resources Information Center

    American Bar Association, Chicago, IL.

    This publication presents 10 documents collected to accompany a seminar entitled "What To Do When Contagious Disease Strikes Your School," presented at the 31st annual convention of the National Organization on Legal Problems of Education in 1985. The materials include (1) an agenda of the seminar listing the speakers, their topics, and the time…

  20. Topic 101: Eleven Campuses, One University, Many Strikes

    ERIC Educational Resources Information Center

    Navarro-Rivera, Pablo

    2010-01-01

    Students from the University of Puerto Rico (UPR) went on strike in April, and, soon after, 10 of the 11 campuses of a public system with more than 60,000 students were closed. "Once recintos, una universidad" (eleven campuses, one university) was the maxim students used to emphasize the concept of the UPR as a system unified by similar goals,…

  1. Strike-slip Faulting On Ganymede, Now And Then

    NASA Astrophysics Data System (ADS)

    Pappalardo, Robert T.; Smith-Konter, B. R.; Cameron, M. E.; DeRemer-Keeney, L. C.; Nimmo, F.

    2012-10-01

    Strike-slip tectonism is important to the structural development of Ganymedes surface, and in the transition from dark to grooved terrain. Three distinct signatures of strike-slip faulting are recognized [1]: (1) en echelon structures, (2) strike-slip duplexes, and (3) laterally offset pre-existing features. As strike-slip faulting progressed, en echelon fractures (in both dark and grooved terrains) merged to define en echelon swaths, which can become distinct tectonic domains. Three morphological categories of strike-slip duplexes (spindle-shaped lensoid regions bounded by strike-slip faults) occur, suggesting an evolutionary sequence from discontinuous fractures in dark terrain, to lensoid bounding structures, to lensoid regions with subparallel internal structure in grooved terrain. Ganymedes 24 measured duplexes have an average length/width ratio of 2.4, on the low end of the terrestrial range [2]. Lateral offsets of pre-existing features betray the existence of some major strike-slip faults: Dardanus Sulcus (13W, 18S) is displaced 45 km by a prominent NE-SW trending fault. We model Coulomb shear failure on Ganymede, considering nonsynchronous rotation (NSR), and diurnal stresses both for present (0.0013) and possible past high ( 0.05) eccentricity [3]. We adopt NSR period 0.14 Ma; Love numbers h2 = 1.52 and l2 = 0.38; Youngs modulus 9.3 GPa; Poissons ratio 0.33; and fault depth 2 km. NSR shear stress resolved along the Dardanus fault is 0.3 MPa, sufficient to induce failure to 1.4 km for friction coefficient 0.3. For past high eccentricity, diurnal stress would have modulated NSR stress by 100 kPa through Ganymedes tidal cycle. This could have induced shear heating [4] and tidal walking [5], as modeled for Europa. References: [1] DeRemer and Pappalardo (2003), LPSC, 34, #2033; [2] Aydin and Nur (1982), Tectonics, 1, 91; [3] Showman and Malhotra (1997), Icarus, 127, 93; [4] Nimmo and Gaidos (2002), JGR, 107, 10.1029/2000JE001476; [5] Rhoden et al. (2012), Icarus, 218, 297.

  2. Global seismicity characteristics of subduction-to-strike-slip transitions

    NASA Astrophysics Data System (ADS)

    Bilich, Andria; Frohlich, Cliff; Mann, Paul

    2001-09-01

    There are at least 30 major plate boundary segments worldwide where the plate boundary changes from subduction to strike-slip; these include six triple junctions and 24 two-plate boundaries. This study investigates earthquake seismicity in the 24 two-plate subduction-to-strike-slip transition (SSST) regions by utilizing recently published earthquake relocations, ternary diagrams of focal mechanisms, and moment rate calculations. To facilitate cross-regional comparisons, we categorize the geometry of SSST plate boundaries in terms of (1) their radius of curvature, (2) their sense of curvature, that is, whether they are convex or concave as viewed from the downgoing plate, and (3) their tectonic complexity, that is, the variability of crustal thickness and the segmentation of the plate boundary trace. We observe three main trends in SSST regions: (1) there is a conspicuous scarcity of strike-slip earthquakes along plate boundary segments that plate motion models indicate are strike-slip boundaries; (2) in these apparent strike-slip segments, both the rate of occurrence of earthquakes of any kind and the moment release rate are low compared to adjacent subduction segments; and (3) there were few observable differences in seismicity between convex and concave boundaries. The observation that transform zones exhibit moment rate deficiencies, that is, have few large-magnitude earthquakes in the historical record, may have important implications for seismic hazard assessment in SSST regions. In particular, is motion along these boundaries aseismic with little seismic hazard, or is motion expressed in very large magnitude, infrequent, but potentially devastating earthquakes? In at least three such regions, New Zealand, the Philippines, and the Dominican Republic, paleoseismic evidence and the historical record of seismicity suggest that very large, infrequent earthquakes do occur.

  3. Strike-slip earthquakes on moderately-dipping faults

    NASA Astrophysics Data System (ADS)

    Van Horne, Anne; Hubbard, Judith; Sato, Hiroshi; Takeda, Tetsuya

    2014-05-01

    Moderate-angle faults that form under compressive stress regimes in subduction zones can slip laterally if the stress field subsequently reorients to strike-slip. We present three examples from Japan and Pakistan in which regional-scale thrust faults created in compressional structural settings have been reactivated as strike-slip faults in new, largely subhorizontal, stress fields. (1) In SW Japan, the Median Tectonic Line has a dip of 30-40, yet it slips laterally in the slip-partitioned Nankai subduction margin. (2) Likewise, the source fault for the M7.9 Great Kanto earthquake was the Sagami megathrust, yet it exhibited predominantly strike-slip movement in the 1923 earthquake. (3) In Pakistan, the 2013 M7.7 Awaran earthquake occurred on a fault plane that dips 45 and showed largely strike-slip movement. These are regional-scale, moderate-angle faults that originated as thrust faults at the subduction interface (or in its associated fold-and-thrust belt) and now exhibit near-horizontal slip. While their current slip behavior suggests they should be oriented vertically or near-vertically, they are not. They have inherited a non-typical inclined geometry. Under what conditions does a thrust fault reactivate in a strike-slip stress field? The inherited fault plane must represent a significant preexisting crustal weakness whose coefficient of cohesion exceeds its coefficient of friction, allowing it to fail preferentially despite its unfavorable orientation. Details of the slip behavior for these faults in time and space suggest complex dynamics which will require further scrutiny.

  4. Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics

    PubMed Central

    Valenzuela, Kevin A.; Lynn, Scott K.; Mikelson, Lisa R.; Noffal, Guillermo J.; Judelson, Daniel A.

    2015-01-01

    The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.82.2 years, mass = 73.114.5 kg, height 1.75 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 .21 BW, FFS = 2.71 0.23 BW), dorsiflexion moment (RFS = -2.6 1 0.61 Nmkg-1, FFS = -3.09 0.32 Nmkg-1), and dorsiflexion range of motion (RFS = 17.63 3.76, FFS = 22.10 5.08). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 0.11 Nmkg-1, FFS = 0.01 0.01 Nmkg-1), peak knee moment (RFS = 2.61 0.54 Nmkg-1, FFS = 2.39 0.61 Nmkg-1), knee ROM (RFS = 31.72 2.79, FFS = 29.58 2.97), and hip ROM (RFS = 42.72 4.03, FFS = 41.38 3.32) as compared with the FFS condition. This research suggests that acute changes in foot strike patterns during shod running can create alterations in certain lower limb kinematic and kinetic measures that are not dependent on the preferred foot strike pattern of the individual. This research also challenges the contention that the impact transient spike in the vertical ground reaction force curve is only present during a rear foot strike type of running gait. Key points Footstrike pattern changes should be individually considered and implemented based on individual histories/abilities Forefoot strike patterns increase external dorsiflexion moments Rearfoot strike patterns increase external knee flexion moments Recreational shod runners are able to mimic habitual mechanics of different foot strike patterns PMID:25729311

  5. Effect of Acute Alterations in Foot Strike Patterns during Running on Sagittal Plane Lower Limb Kinematics and Kinetics.

    PubMed

    Valenzuela, Kevin A; Lynn, Scott K; Mikelson, Lisa R; Noffal, Guillermo J; Judelson, Daniel A

    2015-03-01

    The purpose of this study was to determine the effect of foot strike patterns and converted foot strike patterns on lower limb kinematics and kinetics at the hip, knee, and ankle during a shod condition. Subjects were videotaped with a high speed camera while running a 5km at self-selected pace on a treadmill to determine natural foot strike pattern on day one. Preferred forefoot group (PFFG, n = 10) and preferred rear foot group (PRFG, n = 11) subjects were identified through slow motion video playback (n = 21, age = 22.82.2 years, mass = 73.114.5 kg, height 1.75 0.10 m). On day two, subjects performed five overground run trials in both their natural and unnatural strike patterns while motion and force data were collected. Data were collected over two days so that foot strike videos could be analyzed for group placement purposes. Several 2 (Foot Strike Pattern -forefoot strike [FFS], rearfoot strike [RFS]) x 2 (Group - PFFG, PRFG) mixed model ANOVAs (p < 0.05) were run on speed, active peak vertical ground reaction force (VGRF), peak early stance and mid stance sagittal ankle moments, sagittal plane hip and knee moments, ankle dorsiflexion ROM, and sagittal plane hip and knee ROM. There were no significant interactions or between group differences for any of the measured variables. Within subject effects demonstrated that the RFS condition had significantly lower (VGRF) (RFS = 2.58 .21 BW, FFS = 2.71 0.23 BW), dorsiflexion moment (RFS = -2.6 1 0.61 Nmkg(-1), FFS = -3.09 0.32 Nmkg(-1)), and dorsiflexion range of motion (RFS = 17.63 3.76, FFS = 22.10 5.08). There was also a significantly higher peak plantarflexion moment (RFS = 0.23 0.11 Nmkg(-1), FFS = 0.01 0.01 Nmkg(-1)), peak knee moment (RFS = 2.61 0.54 Nmkg(-1), FFS = 2.39 0.61 Nmkg(-1)), knee ROM (RFS = 31.72 2.79, FFS = 29.58 2.97), and hip ROM (RFS = 42.72 4.03, FFS = 41.38 3.32) as compared with the FFS condition. This research suggests that acute changes in foot strike patterns during shod running can create alterations in certain lower limb kinematic and kinetic measures that are not dependent on the preferred foot strike pattern of the individual. This research also challenges the contention that the impact transient spike in the vertical ground reaction force curve is only present during a rear foot strike type of running gait. Key pointsFootstrike pattern changes should be individually considered and implemented based on individual histories/abilitiesForefoot strike patterns increase external dorsiflexion momentsRearfoot strike patterns increase external knee flexion momentsRecreational shod runners are able to mimic habitual mechanics of different foot strike patterns. PMID:25729311

  6. Use of GNSS data for Hydrology: Applications of the method PPP (Precise Point Positioning) with integer ambiguities fixing for hydrological studies in the Amazon basin

    NASA Astrophysics Data System (ADS)

    Moreira, D. M.; Calmant, S.; Perosanz, F.; Santos, A.; Santos Da Silva, J.; Seyler, F.; Ramillien, G. L.; Monteiro, A.; Rotunno, O.; Shum, C.

    2011-12-01

    Applications of GNSS data is constantly being used in hydrology. One of the key applications is the characterization of river's longitudinal profiles, an information required to develop hydrological and hydrodynamic studies and to evaluate the quality of data obtained through space altimetry techniques. Some factors illustrate the challenge of establishing quality altimetry data from a GNSS receivers to obtain rivers profiles in Amazon Basin. GNSS reference network is sparse, the distance between survey points and reference stations is large, rivers have an extension of several thousands of kilometers. All these factors contribute in limiting the efficiency of classical techniques of GNSS data processing like double difference. In the present work we use the Gins-PC software developed at CNES / GRGS. We discuss the capability of the PPP kinematic with integer ambiguities fixing strategy implemented in GINS-PC in processing GPS data to calculate river's longitudinal profiles in the Amazon Basin. The profiles will be processed using data obtained from GPS receivers on boarding boats along the rivers of Amazon Basin such as Negro river, Madeira river and Amazon/Solimes river. For this purpose, field campaings were conducted between 2005 and 2010 by ANA ( Brazilian National Water Agency), CPRM (Brazilian Geologic Survey), IRD (French Institute of Research by Development), Hybam ( Hydrology of Amazon Basin), PROSUL (Research project by CNPQ/UFRJ) and FOAM (From Ocean to inland waters Altimetry Monitoring) river section project. Under the proposed framework, these profiles will be then compared with profiles obtained by water level variation data using altimetry data from tracks of the Jason-2 and ENVISAT missions. The profiles will be also used to levelling some gauge stations in Amazon Basin and gauge data will be used to obtain a temporal variation of these profiles. However some gauges are strongly affected by charge effects, mainly caused by the hydrological cycle of the Amazon basin. These effects can produce a variation of about 10 cm in amplitude of vertical coordinates also obtained by GPS. Therefore, we use GRACE data to convert the hydrologic load into crustal displacements to remove these effects.

  7. Update Direct-Strike Lightning Environment for Stockpile-to-Target Sequence

    SciTech Connect

    Uman, M A; Rakov, V A; Elisme, J O; Jordan, D M; Biagi, C J; Hill, J D

    2008-10-01

    The University of Florida has surveyed all relevant publications reporting lightning characteristics and presents here an up-to-date version of the direct-strike lightning environment specifications for nuclear weapons published in 1989 by R. J. Fisher and M. A. Uman. Further, we present functional expressions for current vs. time, current derivative vs. time, second current derivative vs. time, charge transfer vs. time, and action integral (specific energy) vs. time for first return strokes, for subsequent return strokes, and for continuing currents; and we give sets of constants for these expressions so that they yield approximately the median and extreme negative lightning parameters presented in this report. Expressions for the median negative lightning waveforms are plotted. Finally, we provide information on direct-strike lightning damage to metals such as stainless steel, which could be used as components of storage containers for nuclear waste materials; and we describe UF's new experimental research program to add to the sparse data base on the properties of positive lightning. Our literature survey, referred to above, is included in four Appendices. The following four sections (II, III, IV, and V) of this final report deal with related aspects of the research: Section II. Recommended Direct-Strike Median and Extreme Parameters; Section III. Time-Domain Waveforms for First Strokes, Subsequent Strokes, and Continuing Currents; Section IV. Damage to Metal Surfaces by Lightning Currents; and Section V. Measurement of the Characteristics of Positive Lightning. Results of the literature search used to derive the material in Section II and Section IV are found in the Appendices: Appendix 1. Return Stroke Current, Appendix 2. Continuing Current, Appendix 3. Positive Lightning, and Appendix 4. Lightning Damage to Metal Surfaces.

  8. 3-D simulation of angled strike heavy-ion induced charge collection in silicon-germanium heterojunction bipolar transistors

    NASA Astrophysics Data System (ADS)

    Jinxin, Zhang; Hongxia, Guo; Lin, Wen; Qi, Guo; Jiangwei, Cui; Xin, Wang; Wei, Deng; Qiwen, Zhen; Xue, Fan; Yao, Xiao

    2014-04-01

    This paper presents 3-D simulation of angled strike heavy-ion induced charge collection in domestic silicon-germanium heterojunction bipolar transistors (SiGe HBTs). 3D damaged model of SiGe HBTs single-event effects (SEE) is built by TCAD simulation tools to research ions angled strike dependence. We select several different strike angles at variously typical ions strike positions. The charge collection mechanism for each terminal is identified based on analysis of the device structure and simulation results. Charge collection induced by angled strike ions presents a complex situation. Whether the location of device ions enters, as long as ions track through the sensitive volume, it will cause vast charge collection. The amount of charge collection of SiGe HBT is not only related to length of ions track in sensitive volume, but also influenced by STI and distance between ions track and electrodes. The simulation model is useful to research the practical applications of SiGe HBTs in space, and provides a theoretical basis for the further radiation hardening.

  9. Paleofluid evolution of strike-slip compartmentalized extensional fault zones in the Jabal Qusaybah anticline, Salakh Arc, Oman

    NASA Astrophysics Data System (ADS)

    Balsamo, Fabrizio; Clemenzi, Luca; Storti, Fabrizio; Mozafari, Mahtab; Solum, John; Swennen, Rudy; Taberner, Conxita; Tueckmantel, Christian

    2015-04-01

    The E-W-trending Jabal Qusaybah anticline, developed in layered Cretaceous carbonates, is located at the western termination of the Salakh Arc, Oman Mountains. The anticline is 10 km long and is characterized by a complex fault pattern which mainly includes NE-SW left-lateral strike-slip and N-S extensional fault zones. The N-S striking extensional fault zones are best developed in the central sector of the anticlinal crest, likely due to along-strike outer-arc extension associated with positive fault inversion and salt migration. Extensional fault zones are perpendicular to the fold axis and geometrically confined within major NE-SW left-lateral strike-slip fault zones. They have trace lengths ranging from a few m up to ~800 m, and displacements ranging from a few dm up to ~60 m. Fault zones consist of cataclastic fault cores (~1-15 cm thick) surrounded by vein-dominated damage zones. Overall, fault zones show significant volumes of dilation breccia texture, m-thick infillings of calcite crystals, and cm- to m-thick veins localized at fault tip zones, areas of fault overlap, and zones of interaction between strike-slip and extensional fault segments. By analyzing fault abutting geometries, detailed vein relative chronology, delta13C and delta18O signatures and fluid inclusion data from calcite veins and calcite fault infillings, we propose a model where a deep seated left-lateral strike-slip fault system, active during the growth of the anticline, inhibited the lateral propagation of late-stage transversal extensional fault zones. Our findings show that, in this geological setting, the structural position, rather than fault throw, is the parameter controlling the location of the more dilatant fault segments.

  10. Implications of Incessant Strike Actions on the Implementation of Technical Education Programme in Nigeria

    ERIC Educational Resources Information Center

    Adavbiele, J. A.

    2015-01-01

    This paper was designed to x-ray the implications of incessant strike actions on the implementation of Technical education programme in Nigeria. The paper took an exploratory view on the concept of strike actions in Nigeria with particular references on notable strike actions that have occurred in Nigeria. The types of strike were explained and…

  11. Control of striking velocity by table tennis players.

    PubMed

    Marinovic, Welber; Iizuka, Cristina Akiko; Freudenheim, Andrea Michele

    2004-12-01

    This study investigated how 7 skilled table tennis players controlled velocity of a forehand drive stroke when the ball's trajectory, velocity, and spin were modified. They hit a target in response to balls launched under four different conditions. The relative and absolute times used in the backswing phase showed no significant differences among conditions. When subjects hit fastballs, there was a significant change in the time required for them to reach the peak of velocity in the forward swing phase. In addition, players decreased the velocity of their strokes to hit fast-approaching balls. These results indicate that highly skilled table tennis players need to adjust the striking velocity and striking time (relative and absolute) required to reach the peak of velocity in the forward swing phase for these task modifications. Since they used slower movement velocities to hit faster-approaching balls, skilled table tennis players may override this speed-coupling process. PMID:15648504

  12. Charge collection and SEU from angled ion strikes

    SciTech Connect

    Dodd, P.E.; Shaneyfelt, M.R.; Sexton, F.W.

    1997-03-01

    Single event upsets (SEUs) are caused in semiconductor microcircuits when charge is deposited in a sensitive volume of the circuit by an incident energetic particle. Collection of this charge causes a loss of information stored at the struck circuit node. Sensitive regions of a microcircuit typically consist of reverse-biased junctions which efficiently collect deposited charge through the influence of drift fields. During laboratory SEU testing, angled ion strikes are often used to conveniently mimic normally incident particles of higher linear energy transfer (LET). This practice is based on ion pathlengths through a thin rectangular parallelepiped (RPP) sensitive volume. Specifically, the authors assume that an angled strike deposits 1/cos{theta} more charge in the sensitive volume, which in turn is assumed to lead to 1/cos{theta} more charge collection at the sensitive node, and an increase in the particle`s effective LET to 1/cos{theta} higher than at normal incidence.

  13. Analysis of direct and nearby lightning strike data for aircraft

    NASA Technical Reports Server (NTRS)

    Giri, D. V.; Noss, R. S.; Phuoc, D. B.; Tesche, F. M.

    1983-01-01

    A method for interpreting direct strike and nearby strike lightning data on aircraft is discussed. The theoretical basis for the interpretation involves a transmission line model for the aircraft, and is discussed. Results of applying this model to the F-106 aircraft are presented and in the natural resonances are computed for several different electrical representations of the aircraft. The signal processing techniques useful for extracting pole (resonance) information from experimental data are discussed, and the use of these techniques on the measured lightning data is illustrated. Finally, the results of a related ground-based lightning experiment are discussed and data are presented. The purpose of this test was to gain additional understanding of the resonance properties of the F-106 aircraft.

  14. Moist bacterial strike-through of surgical materials: confirmatory tests.

    PubMed Central

    Laufman, H; Siegal, J D; Edberg, S C

    1979-01-01

    New tests consisting of modifications of the inverted Mason jar test confirm our previously reported studies which showed that woven and nonwoven surgical materials vary greatly in their ability to serve as barriers against moist bacterial strike-through. Among the woven materials, only tightly woven Pima cloth or materials treated with Quarpel waterproofing process or with polythene layer lamination was invariably resistant. However, tight-woven Pima cloth, which had been treated with Quarpel became permeable after 100 washing-sterilizing cycles. Of the nonwoven materials, single-layer nonwoven materials tended to unevenly permeable to moist bacterial strike-through. Only the front and sleeves of nonwoven gowns reinforced with polyethelene layer were invariably resistant to moist contamination. PMID:758867

  15. Hunt's 'sincere' words only strike a false note.

    PubMed

    Scott, Graham

    2014-10-21

    The first strike by NHS staff over pay in more than 30 years - and the first by members of the Royal College of Midwives in its history - will hopefully force ministers to rethink their decision to freeze pay rates for 1.3 million health service staff. Those taking part in Monday's four-hour stoppage and this week's 'work-to-rule' deserve great credit for making a sacrifice so that everyone in the NHS may benefit. PMID:25315522

  16. A bolt from the blue: lightning strike to the head.

    PubMed

    Cherington, M; Krider, E P; Yarnell, P R; Breed, D W

    1997-03-01

    We report an extraordinary event of a lightning strike to the head of a helmeted bicyclist that occurred under fair weather conditions with a cloudless sky. The patient sustained a cardiac arrest and hypoxic encephalopathy with residual neurologic impairment. With the availability of highly developed meteorologic equipment, we were able to determine that the lightning "bolt from the blue" probably originated in a thunderstorm that was about 16 km away and obscured by the mountains. PMID:9065548

  17. Further identification and treatment modalities in telephone mediated lightning strike

    NASA Technical Reports Server (NTRS)

    Andrews, Christopher J.; Darveniza, Mat

    1991-01-01

    The results are presented of a prospective survey of people injured by lightning impulses transmitted by the public telephone system. The results are compared with those of a previous retrospective survey. Various deficiencies in the methodology of the latter survey are addressed. A division into a population with severe injury and a population with mild injury is made based on medical history and examination taken immediately after a strike. The best predictors of severe injury were found to be the presence of symptoms beyond one week after the strike, and also the initial presence of musculoskeletal injuries. Psychological upset is also seen to be a significant factor in severe injury. The only physical parameter of strike which could be used as a predictor of severe injury was the presence of concomitant power system damage. The importance of earth bonding between power and telephone system is thus supported in a protection strategy. One author draws on experience in treating patients with these injuries to propose a treatment regimen for those with ongoing symptoms. The importance of evaluating and treating psychological and physical aspects is stressed.

  18. The fast and forceful kicking strike of the secretary bird.

    PubMed

    Portugal, Steven J; Murn, Campbell P; Sparkes, Emily L; Daley, Monica A

    2016-01-25

    The study of animal locomotion has uncovered principles that can be applied to bio-inspired robotics, prosthetics and rehabilitation medicine, while also providing insight into musculoskeletal form and function [1-4]. In particular, study of extreme behaviors can reveal mechanical constraints and trade-offs that have influenced evolution of limb form and function [1,2]. Secretary birds (Sagittarius serpentarius; Figure 1A) are large terrestrial birds of prey endemic to sub-Saharan Africa, which feed on snakes, lizards and small mammals [5]. They frequently kick and stamp on the prey's head until it is killed or incapacitated, particularly when dispatching larger lizards and venomous snakes [5]. The consequences of a missed strike when hunting venomous snakes can be deadly [5], so the kicking strikes of secretary birds require fast yet accurate neural control. Delivery of fast, forceful and accurate foot strikes that are sufficient to stun and kill prey requires precision targeting, demanding a high level of coordination between the visual and neuromuscular systems. PMID:26811886

  19. Light-induced bird strikes on vessels in Southwest Greenland.

    PubMed

    Merkel, Flemming Ravn; Johansen, Kasper Lambert

    2011-11-01

    Light-induced bird strikes are known to occur when vessels navigate during darkness in icy waters using powerful searchlight. In Southwest Greenland, which is important internationally for wintering seabirds, we collected reports of incidents of bird strikes over 2-3 winters (2006-2009) from navy vessels, cargo vessels and trawlers (total n=19). Forty-one incidents were reported: mainly close to land (<4 km, 78%), but one as far offshore as 205 km. Up to 88 birds were reported killed in a single incident. All occurred between 5p.m. and 6a.m. and significantly more birds were involved when visibility was poor (snow) rather than moderate or good. Among five seabird species reported, the common eider (Somateria mollissima) accounted for 95% of the bird casualties. Based on spatial analyses of data on vessel traffic intensity and common eider density we are able to predict areas with high risk of bird strikes in Southwest Greenland. PMID:21937064

  20. What can we learn from 20 years of interseismic GPS measurements across strike-slip faults?

    NASA Astrophysics Data System (ADS)

    Vernant, Philippe

    2015-03-01

    I use GPS interseismic velocities and classic 2D elastic half-space models with a screw dislocation to estimate the long-term fault slip rate, locking depth, and the offset between the surface fault trace and the location of the dislocation below the seismogenic zone for 13 segments along 8 major strike-slip faults. Using deduced strike-slip rates and the position of the dislocation to normalize the interseismic velocities to facilitate comparison of spatial patterns of deformation, I show that no substantial differences can be detected, ruling out a large asymmetry in interseismic velocities across the 8 faults used in this study. Only the Carrizo Plain segment of the San Andreas Fault shows a significant asymmetry that cannot be explained by shifting the position of the dislocation at depth relative to the fault trace. However, the resulting perturbation is less than 10% of total strike-slip rate. Fault traces are usually curved, defining a concave side. When the dislocation at depth is significantly offset from the fault trace, the shift is always toward the block on the concave side of the fault trace. This suggests that the fault zone in the lower crust may develop a simpler geometry more consistent with relative motion across the fault than its upper seismogenic part constrained by the structural complexity of the brittle crust. Since the faults used in this study are at different times in their interseismic period, comparing the interseismic velocity fields across them allows identification of possible variations of the interseismic velocities with time. When normalized by slip rate and dislocation location, all the faults show the same interseismic strain with no significant differences between deduced locking depths. These comparisons suggest that if temporal variations occur as suggested by some dynamic earthquake cycle models, they are small and below the accuracy of the available geodetic measurements.

  1. Influence of the Convergence and Stepover Angles in the Structural Style of Strike-Slip Systems: Analogue Models

    NASA Astrophysics Data System (ADS)

    Gonzalez, D.; Pinto, L.

    2008-12-01

    The presented results of analogue models analyze the influence of the relation between the convergence angle and the stepover angle on strike-slip systems. The experiments include 2 stepovers arrays to generate both transpressional and transtensional zones. These experiments were prepared using 5 cm thick sandpack (sand diameter <500 ?m, internal friction angle 30, density 1,400 kg/m3) to simulate brittle deformation; the base of the model was formed by thin zinc base plates, one of them mobile, cut in such a way so as to produce restraining and releasing strike-slip stepovers; the rate convergence was constant. We carried out 3 series of experiments in which the convergence angles (0-60) and stepover angles (30-60) were varied systematically. Preliminary results indicate that by increasing the angle between the stepover and the convergence vector: a) the restraining area generated a positive flower structure that is progressively wider; b) progressively more reverse faults which absorb more shortening were generated. Locally, strike-slip faults in the positive flowers were accommodated by the geometry of the stepover base. Areas most complex involved the development of normal faults, which subsequently were inverted. In conclusion, the relation between the convergence and stepover angles is a main factor that determines the structural style of flowers structures on strike-slip systems. This work was done through the ACT-18 PBCT project.

  2. On strike-slip faulting in layered media

    NASA Astrophysics Data System (ADS)

    Bonafede, Maurizio; Parenti, Beatrice; Rivalta, Eleonora

    2002-06-01

    We study the effects of structural inhomogeneities on the stress and displacement fields induced by strike-slip faults in layered media. An elastic medium is considered, made up of an upper layer bounded by a free surface and welded to a lower half-space characterized by different elastic parameters. Shear cracks with assigned stress drop are employed as mathematical models of strike-slip faults, which are assumed to be vertical and planar. If the crack is entirely embedded within the lower medium (case A), a Cauchy-kernel integral equation is obtained, which is solved by employing an expansion of the dislocation density in Chebyshev polynomials. If the crack is within the lower medium but it terminates at the interface (case B), a generalized Cauchy singularity appears in the integral kernel. This singularity affects the singular behaviour of the dislocation density at the crack tip touching the interface. Finally, the case of a crack crossing the interface is considered (case C). The crack is split into two interacting sections, each placed in a homogeneous medium and both open at the interface. Two coupled generalized Cauchy equations are obtained and solved for the dislocation density distribution of each crack section. An asymptotic study near the intersection between the crack and the interface shows that the dislocation densities for each crack section are bounded at the interface, where a jump discontinuity is present. As a corollary, the stress drop must be discontinuous at the interface, with a jump proportional to the rigidity contrast between the adjoining media. This finding is shown to have important implications for the development of geometrical complexities within transform fault zones: planar strike-slip faults cutting across layer discontinuities with arbitrary stress drop values are shown to be admissible only if the interface between different layers becomes unwelded during the earthquake at the crack/interface junction. Planar strike-slip faulting may take place only in mature transform zones, where a repetitive earthquake cycle has already developed, if the rheology is perfectly elastic. Otherwise, the fault cannot be planar: we infer that strike-slip faulting at depth is plausibly accompanied by en-echelon surface breaks in a shallow sedimentary layer (where the stress drop is lower than prescribed by the discontinuity condition), while ductile deformation (or steady sliding) at depth may be accommodated by multiple fault branching or by antithetic faulting in the upper brittle layer (endowed with lower rigidity but higher stress).

  3. Telescope pointing for GOPEX

    NASA Technical Reports Server (NTRS)

    Owen, W. M., Jr.

    1993-01-01

    In order for photons emitted by the GOPEX lasers to be detected by Galileo's camera, the telescopes at Table Mountain Observatory and Starfire Optical Range had to be pointed in the right direction within a tolerance less than the beam divergence. At both sites nearby stars were used as pointing references. The technical challenge was to ensure that the transmission direction and the star positions were specified in exactly the same coordinate system; given this assurance, neither the uncertainty in the star catalog positions nor the difficulty in offset pointing was expected to exceed the pointing error budget. The correctness of the pointing scheme was verified by the success of GOPEX.

  4. The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin.

    PubMed

    van Hengstum, Peter J; Donnelly, Jeffrey P; Fall, Patricia L; Toomey, Michael R; Albury, Nancy A; Kakuk, Brian

    2016-01-01

    Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present a 3000 year record of intense hurricane strikes in the northern Bahamas (Abaco Island) based on overwash deposits in a coastal sinkhole, which indicates that the ITCZ has likely helped modulate intense hurricane strikes on the western North Atlantic margin on millennial to centennial-scales. The new reconstruction closely matches a previous reconstruction from Puerto Rico, and documents a period of elevated intense hurricane activity on the western North Atlantic margin from 2500 to 1000 years ago when paleo precipitation proxies suggest that the ITCZ occupied a more northern position. Considering that anthropogenic warming is predicted to be focused in the northern hemisphere in the coming century, these results provide a prehistoric analog that an attendant northern ITCZ shift in the future may again return the western North Atlantic margin to an active hurricane interval. PMID:26906670

  5. The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin

    NASA Astrophysics Data System (ADS)

    van Hengstum, Peter J.; Donnelly, Jeffrey P.; Fall, Patricia L.; Toomey, Michael R.; Albury, Nancy A.; Kakuk, Brian

    2016-02-01

    Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present a 3000 year record of intense hurricane strikes in the northern Bahamas (Abaco Island) based on overwash deposits in a coastal sinkhole, which indicates that the ITCZ has likely helped modulate intense hurricane strikes on the western North Atlantic margin on millennial to centennial-scales. The new reconstruction closely matches a previous reconstruction from Puerto Rico, and documents a period of elevated intense hurricane activity on the western North Atlantic margin from 2500 to 1000 years ago when paleo precipitation proxies suggest that the ITCZ occupied a more northern position. Considering that anthropogenic warming is predicted to be focused in the northern hemisphere in the coming century, these results provide a prehistoric analog that an attendant northern ITCZ shift in the future may again return the western North Atlantic margin to an active hurricane interval.

  6. The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin

    PubMed Central

    van Hengstum, Peter J.; Donnelly, Jeffrey P.; Fall, Patricia L.; Toomey, Michael R.; Albury, Nancy A.; Kakuk, Brian

    2016-01-01

    Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present a 3000 year record of intense hurricane strikes in the northern Bahamas (Abaco Island) based on overwash deposits in a coastal sinkhole, which indicates that the ITCZ has likely helped modulate intense hurricane strikes on the western North Atlantic margin on millennial to centennial-scales. The new reconstruction closely matches a previous reconstruction from Puerto Rico, and documents a period of elevated intense hurricane activity on the western North Atlantic margin from 2500 to 1000 years ago when paleo precipitation proxies suggest that the ITCZ occupied a more northern position. Considering that anthropogenic warming is predicted to be focused in the northern hemisphere in the coming century, these results provide a prehistoric analog that an attendant northern ITCZ shift in the future may again return the western North Atlantic margin to an active hurricane interval. PMID:26906670

  7. Source characteristics of large strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Song, Seok-Goo

    We investigate complex earthquake source processes using both spontaneous dynamic rupture modeling and kinematic finite-source inversion. Dynamic rupture modeling is an efficient tool with which we can examine how stress conditions and frictional behavior on a fault plane play a role in determining kinematic motions on the fault and the resulting ground motions at the Earth's surface. It enables us to develop a physical understanding of the earthquake rupture process in terms of Newtonian mechanics. We construct a set of spontaneous dynamic rupture models for several recent earthquakes in Japan and California in order to have a physical understanding of the earthquake source processes for several specific events. Our dynamic models are used to investigate the scaling properties of dynamic source parameters, i.e., fracture energy and stress drop. Many interesting features of the earthquake source process can also be inferred from the kinematic source inversion of observed seismic or geodetic data. We carry out a comprehensive source study of the 1906 San Francisco earthquake by re-analyzing both geodetic and seismic data in order to reconcile two existing, and mutually inconsistent, source models and obtain a unified one. Our study has important implications for seismic hazard in California, and perhaps more generally for large strike-slip earthquakes. Lastly it is important to utilize our knowledge of the earthquake source to improve our understanding of near-field ground motion characteristics because source complexities are quite uncertain and can be the dominant factor in determining the characteristics of near-field ground motion. We develop a pseudo-dynamic source modeling method with which we can generate physically self-consistent finite source models of large strike-slip earthquakes without high-cost, fully dynamic rupture simulation. The new pseudo-dynamic modeling method enables us to effectively characterize the earthquake source complexities for realistic ground motion simulation, especially for large strike-slip events.

  8. Along-strike translation of a fossil slab

    NASA Astrophysics Data System (ADS)

    Eichenbaum-Pikser, J. M.; Forsyth, D. W.; Hirth, G.

    2011-12-01

    The Isabella anomaly is a high seismic velocity anomaly beneath the southern Central Valley of California. Breaking from previous interpretations of the anomaly as a lithospheric drip (Zandt and Carrigan, 1993) or delaminated Sierra Nevada root (Zandt et al., 2004), Forsyth et al. (2011) propose that it is a remnant slab, left over from Cenozoic subduction, attached to the Monterey microplate and translating along-strike with the Pacific plate underneath the edge of the North American plate. This hypothesis requires the slab to translate hundreds of kilometers along strike while remaining intact and attached to the Pacific plate despite drag from the surrounding asthenosphere and overriding lithosphere. Using COMSOL Multiphysics, we design 3-D finite element fluid flow models to simulate this scenario, and calculate the viscosity ratio required between the slab and the surrounding asthenosphere in order for the slab to translate undeformed. The ratio needed increases with downdip extent of the slab, and decreases with slab dip; for geometries approximating that of our proposed slab, it ranges from 10^2 to 10^4. Given the thermal and hydrological history of the slab, mantle flow laws predict viscosity contrasts greater than or equal to these requirements. As such, we conclude that along-strike translation of a remnant slab is entirely feasible, and serves as possible explanation of the Isabella anomaly. The significance of this finding extends beyond our general understanding of subduction dynamics, in that the presence of such a slab could have interesting implications for the water budget of the San Andreas Fault and its role in aseismic slip.

  9. Numerical modelling of river reorganization along strike-slip faults

    NASA Astrophysics Data System (ADS)

    Simon-Labric, T.; van der Beek, P.; Teyssier, C.; Brocard, G.

    2009-04-01

    Most studies of climate-tectonic interactions have focused on steady state orogens that evolve through orogen-normal convergence. Yet, most orogens have a major component of strike skip (wrenching). Although river captures occur in various kinds of geomorphic settings, they are frequently produced in such orogens by strike-slip faulting. The impacts of river captures are not well quantified because compelling diagnostic features and good quality proximal records are rarely found. CASCADE numerical simulation code (Braun and Sanbridge, 1997) has been modified to model horizontal motion across a strike-slip fault and to witness the evolution of river drainage organization. Two river geometries are used to study the effect of horizontal movement on river drainage system. (1) The first one simulates the deformation of an "isolated crosswise stream". The continued horizontal displacement of streams leads to stream deflection and formation of a deep valley along the fault. The elongation of the river is not limited by the presence of other streams, and the lengthening process lowers river gradients and likely diminishes the river's erosional efficiency. (2) The second geometry simulates two parallel crosswise rivers. In this case, lenghtening ends when drains are brought into contact by strike-slip faults. The physical barrier between them is tectonically removed. Further work is in progress to test the influence of capture on the basin incision. First results seem to show an expected transient increase in local relief and therefore basin incision. Through elongation and capture, deformation in a wrench zone produces a constantly evolving pattern of stream reaches with various incision rates. Drainage basins located upstream from the wrench zone experience a series of sudden captures and longer intervening periods of lengthening and slowing erosion. This results in oscillations in incision rate and internal drainage adjustments. Erosion and landscape, in these wrenched systems, thus operate in permanent disequilibrium. Braun, J. and Sambridge, M., 1997, Modelling landscape evolution on geologic time scales: a new method based on irregular spatial discretization, Basin Research, v.9, pp.27-52.

  10. Nursing strikes: an ethical perspective on the US healthcare community.

    PubMed

    Neiman, Paul

    2011-07-01

    Recent labor disputes between registered nurses and hospitals in Minnesota, California, and Pennsylvania raise moral questions about nurses' professional obligations, nurses' right to collectively bargain to preserve or improve wages, benefits, and working conditions, and patients' right to medical care. Deontology and consequentialism focus too narrowly on nurses and patients, and thus ignore the nature of the healthcare community as a system of competing interests. When considered in this context, nurses' strikes are shown to be consistent with this system of competing interests, and thus are morally permissible. PMID:21646323

  11. Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

    SciTech Connect

    Serianni, G. Brombin, M.; Cervaro, V.; Chitarin, G.; Delogu, R.; Fasolo, D.; Fonnesu, N.; Franchin, L.; Ghiraldelli, R.; Molon, F.; Pasqualotto, R.; Tollin, M.; Veltri, P.; Bonomo, F.; Cristofaro, S.; De Muri, M.; Franzen, P.; Ruf, B.; Schiesko, L.; Muraro, A.

    2015-04-08

    The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features of the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.

  12. Negative ion beam characterisation in BATMAN by mini-STRIKE: Improved design and new measurements

    NASA Astrophysics Data System (ADS)

    Serianni, G.; Bonomo, F.; Brombin, M.; Cervaro, V.; Chitarin, G.; Cristofaro, S.; Delogu, R.; De Muri, M.; Fasolo, D.; Fonnesu, N.; Franchin, L.; Franzen, P.; Ghiraldelli, R.; Molon, F.; Muraro, A.; Pasqualotto, R.; Ruf, B.; Schiesko, L.; Tollin, M.; Veltri, P.

    2015-04-01

    The ITER project requires additional heating provided by two injectors of neutral beams resulting from the neutralisation of accelerated negative ions. To study and optimise negative ion production, the SPIDER test facility (particle energy 100keV; beam current 50A) is under construction in Padova, with the aim of testing beam characteristics and to verify the source proper operation. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon fibre carbon composite tiles. Some prototype tiles have been employed in 2012 as a small-scale version (mini-STRIKE) of the entire system to investigate the features of the beam from BATMAN at IPP-Garching. As the BATMAN beamlets are superposed at the measurement position, about 1m from the grounded grid, an actively cooled copper mask is located in front of the tiles; holes in the mask create an artificial beamlet structure. Recently the mini-STRIKE has been updated, taking into account the results obtained in the first campaign. In particular the spatial resolution of the system has been improved by increasing the number of the copper mask holes. Moreover a custom measurement system has been realized for the thermocouple signals and employed in BATMAN in view of its use in SPIDER. The present contribution gives a description of the new design of the system as well as of the thermocouple measurements system and its field test. A new series of measurements has been carried out in BATMAN. The BATMAN beam characterisation in different experimental conditions is presented.

  13. Fast rupture propagation for large strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, Dun; Mori, Jim; Koketsu, Kazuki

    2016-04-01

    Studying rupture speeds of shallow earthquakes is of broad interest because it has a large effect on the strong near-field shaking that causes damage during earthquakes, and it is an important parameter that reflects stress levels and energy on a slipping fault. However, resolving rupture speed is difficult in standard waveform inversion methods due to limited near-field observations and the tradeoff between rupture speed and fault size for teleseismic observations. Here we applied back-projection methods to estimate the rupture speeds of 15 Mw ≥ 7.8 dip-slip and 8 Mw ≥ 7.5 strike-slip earthquakes for which direct P waves are well recorded in Japan on Hi-net, or in North America on USArray. We found that all strike-slip events had very fast average rupture speeds of 3.0-5.0 km/s, which are near or greater than the local shear wave velocity (supershear). These values are faster than for thrust and normal faulting earthquakes that generally rupture with speeds of 1.0-3.0 km/s.

  14. Injury pattern analysis of helicopter wire strike accidents (-Gz load).

    PubMed

    Farr, W D; Ruehle, C J; Posey, D M; Wagner, G N

    1985-12-01

    Injury patterns in rotary wing aircraft wire strike accidents were reviewed to determine mechanisms of injury. It was found that U.S. Army Safety Center data showed that between 1 January 1974 and 31 August 1981 there were 167 wire strikes involving Army helicopters which resulted in 60 injuries and 34 fatalities at a cost of $12,809,100. Updated data on all military rotary wing aircraft accidents investigated between 1978 and 1982 were screened by the Division of Aerospace Pathology to determine the mechanisms of injury to flight deck personnel. From 13 December 1978 to 23 June 1982, three types of rotary wing aircraft were in eight fatal accidents. These mishaps accounted for 28 casualties: 14 fatalities and 14 injuries. Aviators comprised 64.4% of the fatalities. Injury pattern analysis showed 100% had major head and neck injuries with 66% having basilar skull fractures. Two-thirds had associated mandibular fractures or evidence of impact forces transmitted through the mandible to the skull. The same number had wedge-shaped chin lacerations from impact with the cyclic control stick. We postulate transmission of lethal impact forces primarily in the +Gz direction through the mandible to the skull. This suggests either improper use and/or failure of the seat and restraint systems. PMID:4084179

  15. Along-strike translation of a fossil slab

    NASA Astrophysics Data System (ADS)

    Pikser, Jacob E.; Forsyth, Donald W.; Hirth, Greg

    2012-05-01

    The Isabella anomaly is a high seismic velocity anomaly beneath the southern Central Valley of California that has previously been interpreted to represent a lithospheric drip or delaminated Sierra Nevada root. However, recent work suggests that the anomaly is a remnant slab, left over from Cenozoic subduction, attached to the Pacific plate underneath the edge of the North American plate. This hypothesis requires the slab to translate hundreds of kilometers along-strike while remaining intact and attached to the Pacific plate despite drag from the surrounding asthenosphere and overriding lithosphere. We use 3-D finite element models to simulate this scenario, and calculate the viscosity ratio between the slab and the surrounding asthenosphere required for the slab to translate undeformed. The required viscosity ratio increases with increasing downdip extent of the slab, and decreases with increasing slab dip; for geometries approximating that of our proposed slab, the required ratio ranges from 102 to 104. Given the thermal and petrologic history of the slab, mantle flow laws predict viscosity contrasts greater than or equal to these requirements. As such, we conclude that along-strike translation of a remnant slab is feasible, and serves as a possible explanation of the Isabella anomaly. The significance of this finding extends beyond our general understanding of subduction dynamics, in that the presence of such a slab could have implications for the water budget of the San Andreas Fault and its role in aseismic slip.

  16. Battlespace weather and EM/EO conditions for joint strike support

    NASA Astrophysics Data System (ADS)

    Rosenthal, Jay; Helvey, Roger A.; McGovern, Matt; Greiman, Paul; Cohenour, Bernie; Ruth, Dennis

    1997-09-01

    Battlespace meteorological and oceanographic (METOC) conditions can be defined and displayed using the Navy's C4ISR architecture for use in strike planning, optimizing weapons performance, and postoperation assessment. Using the Tactical Environmental Support System (TESS), METOC satellite imagery has been exploited to derive estimates of temperature and cloud conditions along Tomahawk flight paths, and integrated with operational geometry to support missile launches conducted during Joint Warrior Interoperability Demonstration (JWID-95). The integrated and fused displays were sent from the Battle Management Interoperability Center (BMIC) at the Naval Air Warfare Center Weapons Division, Point Mugu, and transmitted to fleet units where they were inserted as strike warfare support products on a home page for transmission to other JWID participants. Other support techniques are also being implemented using home page/internet technology. The EMIEO propagation environment is being characterized remotely by application of the "satellite-JR duct technique" which allows duct heights to be displayed over low-cloud regions over subtropical ocean areas. To provide duct height estimates in regions without clouds or in-situ measurements, or predictions of ducting conditions, the "equivalent altitude" and "experduct" techniques are employed to demonstrate additional automated capabilities using synoptic weather considerations.

  17. Influence of strike object grounding on close lightning electric fields

    NASA Astrophysics Data System (ADS)

    Baba, Yoshihiro; Rakov, Vladimir A.

    2008-06-01

    Using the finite difference time domain (FDTD) method, we have calculated vertical electric field Ez, horizontal (radial) electric field Eh, and azimuthal magnetic field H? produced on the ground surface by lightning strikes to 160-m- and a 553-m-high conical strike objects representing the Peissenberg tower (Germany) and the CN Tower (Canada), respectively. The fields were computed for a typical subsequent stroke at distances d' from the bottom of the object ranging from 5 to 100 m for the 160-m tower and from 10 to 300 m for the 553-m tower. Grounding of the 160-m object was assumed to be accomplished by its underground basement represented by a 10-m-radius and 8-m-long perfectly conducting cylinder with or without a reference ground plane located 2 m below. The reference ground plane simulates, to some extent, a higher-conducting ground layer that is expected to exist below the water table. The configuration without reference ground plane actually means that this plane is present, but is located at an infinitely large depth. Grounding of the 553-m object was modeled in a similar manner but in the absence of reference ground plane only. In all cases considered, waveforms of Eh and H? are not much influenced by the presence of strike object, while waveforms of Ez are. Waveforms of Ez are essentially unipolar (as they are in the absence of strike object) when the ground conductivity ? is 10 mS/m (the equivalent transient grounding impedance is several ohms) or greater. Thus, for the CN Tower, for which ? ? 10 mS/m, the occurrence of Ez polarity change is highly unlikely. For the 160-m tower and for ? = 1 and 0.1 mS/m, waveforms of Ez become bipolar (exhibit polarity change) at d' ? 10 m and d' ? 50 m, respectively, regardless of the presence of the reference ground plane. The corresponding equivalent transient grounding impedances are about 30 and 50 ? in the absence of the reference ground plane and smaller than 10 ? in the presence of the reference ground plane. The source of opposite polarity Ez is the potential rise at the object base (at the air/ground interface) relative to the reference ground plane. For a given grounding electrode geometry, the strength of this source increases with decreasing ?, provided that the grounding impedance is linear. Potential rises at the strike object base for ? = 1 and 0.1 mS/m are some hundreds of kilovolts, which is sufficient to produce electrical breakdown from relatively sharp edges of the basement over a distance of several meters (or more) along the ground surface. The resultant ground surface arcs will serve to reduce the equivalent grounding impedance and, hence, potential rise. Therefore, the polarity change of Ez near the Peissenberg tower, for which ? is probably about 1 mS/m, should be a rare phenomenon, if it occurs at all. The equivalent transient grounding impedance of the cylindrical basement is similar to that of a hemispherical grounding electrode of the same radius. For the 160-m tower and for hemispherical grounding electrode, the transient grounding impedance is higher than its dc grounding resistance for ? = 10 and 1 mS/m, but lower for ? = 0.1 mS/m. For the 553-m tower, the transient grounding impedance of hemispherical electrode is equal to or larger than its dc resistance for all values of ? considered.

  18. Modeling raindrop strike performance on copper wash-off from vine leaves.

    PubMed

    Prez-Rodrguez, P; Soto-Gmez, D; Lpez-Periago, J E; Paradelo, M

    2015-03-01

    Copper lost in foliar wash-off from vine leaves treated with Cu-based fungicides was analyzed with a single-drop rainfall simulator. The temporal losses of the particulate Cu (CuP) and the solution Cu (CuS) from raindrop strikes on leaves were modeled using a Poisson point process. This model estimated maximum detachment rates of 0.82ng CuP and 0.033ng CuS per raindrop. The total amount of Cu (CuT) in the leaves before rainfall ranged between 0.4 and 4.4g Cu kg(-1) dry weight. Wash-off reduced the amount of CuT present in the leaves by 0.6gkg(-1). Particulate losses of CuT ranged from 75 to 90%, while soluble losses of CuT ranged from 10 to 25%. The kinetic energy of the raindrops influenced the loss of CuS but not the loss of CuP. The Poisson point approach can provide an interesting starting point to model non-point source pollution produced from agricultural chemicals washed-off by rain. PMID:25560655

  19. The limits of language: ethical aspects of strike action from a New Zealand perspective.

    PubMed

    Bickley, J

    1997-07-01

    Over the last decade, successive New Zealand governments have instituted social, political and economic changes that have fundamentally challenged nurses' sense of themselves and their position in society. Major upheavals in the health service have occurred as a result of reforms promoting competition and contestability. This paper deals with the impact of one aspect of the reforms, that of the deregulation of the labour market through the Employment Contracts Act 1991. More specifically, the way in which discussions and decisions regarding the withdrawal of nursing labour are shaped by the language available to those involved are considered. The intersection of ethics and union discourses may exacerbate feelings of ambiguity and confusion in nurses facing strike action. The result can be unnecessary and unproductive division and conflict: among nurses, between employers and employees, between unions, between nurses and the public, and between nursing organizations and the Government. An examination of some of the discourses of strike action may serve as a tool to elucidate the way nurses see themselves and their clients in the context of social change and social action. PMID:9305126

  20. Spatial distribution of lightning strikes to ground during small thunderstorms in Florida

    NASA Technical Reports Server (NTRS)

    Krider, E. Philip

    1988-01-01

    The spatial patterns of the strike points produced by cloud-to-ground lightning under three small thunderstorms have been analyzed to determine the area flash density as a function of radius from the storm center, the distribution of the nearest-neighbor distances, and the distribution of the horizontal distances between successive flashes. The storm average flash densities range from about 0.8 to 1.6 Fl/km squared, and the average lightning fluxes range from 0.03 to 0.05 Fl/km squared/min. The mean nearest-neighbor distances are about 0.7 km and smaller, but are still in good agreement with a theory that assumes an infinite and uniform flash density. The mean distance between successive flashes ranges from 3.2 to 4.2 km, and a sizable fraction of this variation could be due to channel geometry.

  1. Industrial Actions in Schools: Strikes and Student Achievement. NBER Working Paper No. 16846

    ERIC Educational Resources Information Center

    Baker, Michael

    2011-01-01

    While many jurisdictions ban teacher strikes on the assumption that they harm students, there is surprisingly little research on this question. The majority of existing studies make cross section comparisons of students who do or do not experience a strike, and report that strikes do not affect student performance. I present new estimates from a

  2. Preparing for a Strike and Living with It After It Happens.

    ERIC Educational Resources Information Center

    Irwin, James R.

    Even though usually no one wants a strike in the schools, the trend during the last decade has been toward greater union activity on behalf of teachers, administrators, and other groups involved with the schools. The inevitable result has been an increase in the number not only of teacher strikes, but of administrator strikes as well. But usually

  3. Water accumulation below Europa's strike-slip faults

    NASA Astrophysics Data System (ADS)

    Kalousova, K.; Tobie, G.; Soucek, O.; Choblet, G.; Cadek, O.

    2015-10-01

    The onset of melting below Europa's recently active strike-slip faults and the gravitational/thermal stability of partially molten ice are investigated by solving the equations for a two-phase compressible mixture of water ice and liquid water in 2D geometry. As a first step, the relative motion between ice and water is neglected, i.e. the meltwater is transported by the flowing ice. Our preliminary results suggest that for sufficiently large shear heating rate of˜2×10-4W m-3 melting can occur at depths as shallow as˜3km below Europa's surface. Moreover, the reservoirs of partially molten ice with˜5-10% of liquid water can remain within the cold lid for a few hundreds of kiloyears if the underlying ice is sufficiently cold (vis-cous) and free of fractures.

  4. A Probabilistic, Facility-Centric Approach to Lightning Strike Location

    NASA Technical Reports Server (NTRS)

    Huddleston, Lisa L.; Roeder, William p.; Merceret, Francis J.

    2012-01-01

    A new probabilistic facility-centric approach to lightning strike location has been developed. This process uses the bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to determine the probability that the stroke is inside any specified radius of any location, even if that location is not centered on or even with the location error ellipse. This technique is adapted from a method of calculating the probability of debris collisionith spacecraft. Such a technique is important in spaceport processing activities because it allows engineers to quantify the risk of induced current damage to critical electronics due to nearby lightning strokes. This technique was tested extensively and is now in use by space launch organizations at Kennedy Space Center and Cape Canaveral Air Force Station. Future applications could include forensic meteorology.

  5. Reactivated strike slip faults: examples from north Cornwall, UK

    NASA Astrophysics Data System (ADS)

    Kim, Young-Seog; Andrews, Jim R.; Sanderson, David J.

    2001-10-01

    Several strike-slip faults at Crackington Haven, UK show evidence of right-lateral movement with tip cracks and dilatational jogs, which have been reactivated by left-lateral strike-slip movement. Evidence for reactivation includes two slickenside striae on a single fault surface, two groups of tip cracks with different orientations and very low displacement gradients or negative (left-lateral) displacements at fault tips. Evidence for the relative age of the two strike-slip movements is (1) the first formed tip cracks associated with right-lateral slip are deformed, whereas the tip cracks formed during left-lateral slip show no deformation; (2) some of the tip cracks associated with right-lateral movement show left-lateral reactivation; and (3) left-lateral displacement is commonly recorded at the tips of dominantly right-lateral faults. The orientation of the tip cracks to the main fault is 30-70 clockwise for right-lateral slip, and 20-40 counter-clockwise for left-lateral slip. The structure formed by this process of strike-slip reactivation is termed a "tree structure" because it is similar to a tree with branches. The angular difference between these two groups of tip cracks could be interpreted as due to different stress distribution (e.g., transtensional/transpressional, near-field or far-field stress), different fracture modes or fractures utilizing pre-existing planes of weakness. Most of the d- x profiles have similar patterns, which show low or negative displacement at the segment fault tips. Although the d- x profiles are complicated by fault segments and reactivation, they provide clear evidence for reactivation. Profiles that experienced two opposite slip movements show various shapes depending on the amount of displacement and the slip sequence. For a larger slip followed by a smaller slip with opposite sense, the profile would be expected to record very low or reverse displacement at fault tips due to late-stage tip propagation. Whereas for a smaller slip followed by larger slip with opposite sense, the d- x profile would be flatter with no reverse displacement at the tips. Reactivation also decreases the ratio of dmax/ L since for an original right-lateral fault, left lateral reactivation will reduce the net displacement ( dmax) along a fault and increase the fault length ( L). Finally we compare Crackington Haven faults with these in the Atacama system of northern Chile. The Salar Grande Fault (SGF) formed as a left-lateral fault with large displacement in its central region. Later right-lateral reactivation is preserved at the fault tips and at the smaller sub-parallel Cerro Chuculay Fault. These faults resemble those seen at Crackington Haven.

  6. A striking reduction of simple loudness adaptation in autism.

    PubMed

    Lawson, Rebecca P; Aylward, Jessica; White, Sarah; Rees, Geraint

    2015-01-01

    Reports of sensory disturbance, such as loudness sensitivity or sound intolerance, are ubiquitous in Autism Spectrum Disorder (ASD) but a mechanistic explanation for these perceptual differences is lacking. Here we tested adaptation to loudness, a process that regulates incoming sensory input, in adults with ASD and matched controls. Simple loudness adaptation (SLA) is a fundamental adaptive process that reduces the subjective loudness of quiet steady-state sounds in the environment over time, whereas induced loudness adaptation (ILA) is a means of generating a reduction in the perceived volume of louder sounds. ASD participants showed a striking reduction in magnitude and rate of SLA relative to age and ability-matched typical adults, but in contrast ILA remained intact. Furthermore, rate of SLA predicted sensory sensitivity coping strategies in the ASD group. These results provide the first evidence that compromised neural mechanisms governing fundamental adaptive processes might account for sound sensitivity in ASD. PMID:26537694

  7. A striking reduction of simple loudness adaptation in autism

    PubMed Central

    Lawson, Rebecca P.; Aylward, Jessica; White, Sarah; Rees, Geraint

    2015-01-01

    Reports of sensory disturbance, such as loudness sensitivity or sound intolerance, are ubiquitous in Autism Spectrum Disorder (ASD) but a mechanistic explanation for these perceptual differences is lacking. Here we tested adaptation to loudness, a process that regulates incoming sensory input, in adults with ASD and matched controls. Simple loudness adaptation (SLA) is a fundamental adaptive process that reduces the subjective loudness of quiet steady-state sounds in the environment over time, whereas induced loudness adaptation (ILA) is a means of generating a reduction in the perceived volume of louder sounds. ASD participants showed a striking reduction in magnitude and rate of SLA relative to age and ability-matched typical adults, but in contrast ILA remained intact. Furthermore, rate of SLA predicted sensory sensitivity coping strategies in the ASD group. These results provide the first evidence that compromised neural mechanisms governing fundamental adaptive processes might account for sound sensitivity in ASD. PMID:26537694

  8. Electrical Characterizations of Lightning Strike Protection Techniques for Composite Materials

    NASA Technical Reports Server (NTRS)

    Szatkowski, George N.; Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Mielnik, John J.

    2009-01-01

    The growing application of composite materials in commercial aircraft manufacturing has significantly increased the risk of aircraft damage from lightning strikes. Composite aircraft designs require new mitigation strategies and engineering practices to maintain the same level of safety and protection as achieved by conductive aluminum skinned aircraft. Researchers working under the NASA Aviation Safety Program s Integrated Vehicle Health Management (IVHM) Project are investigating lightning damage on composite materials to support the development of new mitigation, diagnosis & prognosis techniques to overcome the increased challenges associated with lightning protection on composite aircraft. This paper provides an overview of the electrical characterizations being performed to support IVHM lightning damage diagnosis research on composite materials at the NASA Langley Research Center.

  9. Foot-strike haemolysis after a 60-km ultramarathon

    PubMed Central

    Lippi, Giuseppe; Schena, Federico; Salvagno, Gian Luca; Aloe, Rosalia; Banfi, Giuseppe; Guidi, Gian Cesare

    2012-01-01

    Background. The various contributors to sport-related anaemia include increased plasma volume, exercise-induced oxidative stress, increased body temperature, acidosis, gastrointestinal bleeding, acute and chronic inflammation as well as compression and damage of red blood cells (RBC) in the capillaries within the contracting muscles. The effective contribution of foot-strike haemolysis is unclear. Materials and methods. We studied 18 Caucasian male athletes (mean age, 42 years; range, 34–52 years) before and immediately after a 60-km ultramarathon. Laboratory investigations included the haematological profile along with haptoglobin, potassium, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH) and albumin concentrations and a haemolysis index (HI). Results. No significant variations were found in post-exercise values of haemoglobin, RBC count and haematocrit. Mean corpuscular volume and haptoglobin were significantly decreased, whereas RBC distribution width was increased. The concentration of haptoglobin was reduced by approximately 50%, whereas enzyme concentrations were all remarkably increased. The HI remained below 0.5 g/L. After adjusting for plasma volume change, the increases were 1.7% for potassium (P=0.17), 30% for AST (P<0.01), 49% for LDH (P<0.01) and 2.39-fold for CK (P<0.01). A statistically significant association was found between haemoconcentration-adjusted variations of CK and those of AST (r=0.803; P<0.01) and LDH (r=0.551; P=0.02). Discussion. This is the first study demonstrating that long-distance running does not induce clinically significant changes in haemoglobin, haematocrit, RBC count or potassium concentration. The significant post-exercise decrease of haptoglobin reflects a certain degree of haemolysis, but the concentration of cell-free haemoglobin remaining below 0.5 g/L and the non-significant variation in RBC count both indicate that the foot-strike haemolysis is very modest or even clinically negligible. PMID:22682343

  10. Lightning Strike Induced Damage Mechanisms of Carbon Fiber Composites

    NASA Astrophysics Data System (ADS)

    Kawakami, Hirohide

    Composite materials have a wide application in aerospace, automotive, and other transportation industries, because of the superior structural and weight performances. Since carbon fiber reinforced polymer composites possess a much lower electrical conductivity as compared to traditional metallic materials utilized for aircraft structures, serious concern about damage resistance/tolerance against lightning has been rising. Main task of this study is to clarify the lightning damage mechanism of carbon fiber reinforced epoxy polymer composites to help further development of lightning strike protection. The research on lightning damage to carbon fiber reinforced polymer composites is quite challenging, and there has been little study available until now. In order to tackle this issue, building block approach was employed. The research was started with the development of supporting technologies such as a current impulse generator to simulate a lightning strike in a laboratory. Then, fundamental electrical properties and fracture behavior of CFRPs exposed to high and low level current impulse were investigated using simple coupon specimens, followed by extensive parametric investigations in terms of different prepreg materials frequently used in aerospace industry, various stacking sequences, different lightning intensity, and lightning current waveforms. It revealed that the thermal resistance capability of polymer matrix was one of the most influential parameters on lightning damage resistance of CFRPs. Based on the experimental findings, the semi-empirical analysis model for predicting the extent of lightning damage was established. The model was fitted through experimental data to determine empirical parameters and, then, showed a good capability to provide reliable predictions for other test conditions and materials. Finally, structural element level lightning tests were performed to explore more practical situations. Specifically, filled-hole CFRP plates and patch-repaired CFRP plates were selected as structural elements likely to be susceptible to lightning event. This study forms a solid foundation for the understanding of lightning damage mechanism of CFRPs, and become an important first step toward building a practical damage prediction tool of lighting event.

  11. Lightning strike as probable cause of death and determining identity based on the examination of skeletal remains.

    PubMed

    Hauser, Roman; Kaliszan, Micha?; Basir, Aaron; Basir, Iwona Dawlidowicz-

    2013-03-01

    In this article, a case of examining an incomplete human skeleton found in a forest is presented. Based on the assessment of posttraumatic lesions in the skull bones, the cause of death of a man who had died 14years prior to the examination was determined with high probability to be due to a lightning strike. Moreover, the rare pathological lesions within the skeleton, such as a healed fracture of the humerus and rheumatoid malformations within the hand, in reference to preserved medical records, have also allowed to identify the deceased. Most noteworthy points in this case are, however, initially difficult to comprehend, posttraumatic lesions within the bones of the skull such as carbonization and fracture of the vertex. Their origin can be explained by a lightning strike as the most probable cause of death. Thus, the presented case demonstrates probable cause of death and identity can be established many years after death, based on skeletal remains. PMID:23488549

  12. Precision Strike Training in Lean Manufacturing: A Workplace Literacy Guidebook [and] Final Report on Precision Strike Workplace Literacy Training at CertainTeed Corporation.

    ERIC Educational Resources Information Center

    National Alliance of Business, Inc., Washington, DC.

    CertainTeed's Precision Strike training program was designed to close the gaps between the current status of its workplace and where that work force needed to be to compete successfully in global markets. Precision Strike included Skills and Knowledge in Lifelong Learning (SKILL) customized, computerized lessons in basic skills, one-on-one

  13. Lightning strike density for the contiguous United States from thunderstorm duration records

    SciTech Connect

    MacGorman, D.R.; Maier, M.W.; Rust, W.D.

    1984-05-01

    An improved lightning ground strike climatology has been obtained from thunderstorm duration data recorded by 450 air weather stations. From lightning strike location data collected in Florida and Oklahoma, it was found that strike density could be estimated from thunderstorm duration by the equation N/sub s/ = 0.054H/sup 1/ /sup 1/, where N/sub s/ is the number of strikes per square kilometer and H is thunderstorm duration in hours. This relationship was applied to thunderstorm duration data from the aviation stations to obtain lightning strike density for the contiguous United States.

  14. Analysis of electromagnetic fields on an F-106B aircraft during lightning strikes

    NASA Technical Reports Server (NTRS)

    Trost, T. F.; Pitts, F. L.

    1982-01-01

    Information on the exterior electromagnetic environment of an aircraft when it is struck by lightning has been obtained during thunderstorm penetrations with an F-106B aircraft. Electric and magnetic fields were observed, using mainly time-derivative type sensors, with bandwidths to 50 MHz. Lightning pulse lengths ranging from 25 ns to 7 microsec have been recorded. Sufficient high-frequency content was present to excite electromagnetic resonances of the aircraft, and peaks in the frequency spectra of the waveforms in the range 7 to 23 MHz are in agreement with the resonant frequencies determined in laboratory scale-model tests. Both positively and negatively charged strikes were experienced, and most of the data suggest low values of peak current.

  15. Statistical Correlation between Red Wood Ant Sites and Neotectonic Strike-Slip Faults

    NASA Astrophysics Data System (ADS)

    Berberich, G.; Klimetzek, D.; Wöhler, C.; Grumpe, A.

    2012-04-01

    Recent research in the West Eifel (West Germany) has demonstrated the correlation of soil gas anomalies and spatial distribution of red wood ant (RWA) mounds along strike-slip faults. RWA can be used as biological indicators for the identification of neotectonic fault systems (Berberich 2010, Schreiber & Berberich 2011). For myrmecologists, the causes and stringency of such a linkage are paramount, since linear patterns have been mostly associated with edge effects of forest stands and/or roads (Klimetzek 1970, Klimetzek & Kaiser 1995, Wellenstein 1990). Therefore, geostatistical techniques were applied in the West Eifel and the Bodanrück (South West Germany) to distribution data of approx. 3,000 resp. 2,300 mounds of RWA (Formica spp., Hymenoptera: Formicidae) in correlation with known neotectonic fault systems Both study areas are located in areas with a complex tectonic history. Commenced during the Neogene and persisted during the Quaternary, the uplift of both, the Rhenoherzynikum and the Black Forest, affects the dynamics of the study areas and reactivates pre-existing Palaeozoic crustal discontinuities. The West Eifel (Rhenoherzynikum) was tectonically sheared in Mesozoic and Cenozoic times. The current NW-SE-trending main stress direction opens pathways for geogenic gases. At the same time, Variscan faults as part of a conjugated shear system, are reactivated. At the Bodanrück, the compressional stress field (NNW-SSE) leads to a WSW-ENE extensional regime, in which faults cut through the entire crust (Ziegler & Dèzes 2007, Nagra 1992). The prominent large-scale neotectonic structure is the NW-SE to WNW-ESE trending "Freiburg-Bonndorf-Hegau-Bodensee-Graben" that consists of several sub-trenches (Müller et al. 2002). Field surveys indicate a possible existence of a NNE-SSW trending strike-slip fault extending east of Stein am Rhein (Büchi & Müller 2003) possibly reactivated in the Quaternary (Birkhäuser et al. 2001). Available focal mechanism solutions show a lack of possible fault planes striking between 40 and 90 degrees from north (Deichmann 1990). In addition, a NNW-SSE and NS trending fault system exist. We tested the hypothesis that the spatial distribution of RWA mounds would map the neotectonic stress field directly (Berberich et al. 2012). A statistical method for the automatic extraction of linear patterns from point clouds (Hough transform) was applied to the spatial distribution of RWA mounds. The maxima of the resulting histograms denote the preferential alignment directions. In both cases, it could be clearly shown that the spatial distribution of RWA mounds directly map the main stress field and the conjugated shear system in hierarchically succession. In the West Eifel, RWA depict mainly the opening direction of the Quaternary volcanic field (NW-SE), the WSW-ENE extensional regime and the reactivated Variscan fault systems (NNE-SSW, NE-SW). At the Bodanrück, the hypothesized existence of the NNE-SSW strike-slip fault systems (Büchi & Müller 2003) and additionally NE-SW, NNW-SSE and NS directions could be demonstrated. In conclusion, the statistical analyses show that spatial distribution of RWA maps neotectonic, gaspermeable strike-slip faults. This is especially useful in those cases, where information about the neotectonic regime is incomplete or the resolution by technical means is insufficient.

  16. Reassessment of the maximum magnitude of strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Mignan, Arnaud; Danciu, Laurentiu; Giardini, Domenico

    2015-04-01

    What is the best approach of estimating the true maximum earthquake magnitude (Mmax)? This worst-case sce- nario can be defined as the less probable, never foreseen earthquake size but yet physically possible. Some authors have shown that earthquake observations are not sufficient to statistically estimate Mmax and that some long-term geological constraints should be used. We used as physical constraint the geometry of the fault network and its relation to the regional stress field. Criteria were then defined in a procedure - from the dynamic stress modelling literature - for estimating large cascading known faults into super-size fault lengths and then convert those into refined Mmax values. We developed an algorithm for multi-segment rupture and tested it on the strike-slip faults of the Anatolian Peninsula as defined in the 2013 European Seismic Hazard Model (ESHM13). We find that Mmax is increased locally from about 0.5 to 1.5 units along the North Anatolian Fault and the East Anatolian Fault. A number of other faults show an increase from about 0.5 to 1.0. With longer ruptures being characterized by greater slip and a wider shaking spatial footprint, our results infer a significant change in hazard for most of the Anatolian Peninsula once cascades are considered. Our algorithm is straightforward and does not require extensive calcula- tions, which should make it a simple add-on to consider for improving future stress tests and other seismic hazard analyses.

  17. The assessment of lethal propeller strike injuries in sea mammals.

    PubMed

    Byard, Roger W; Winskog, Calle; Machado, Aaron; Boardman, Wayne

    2012-04-01

    Assessment of injuries in marine mammals may be required to help authorities determine whether human activity was involved. Three cases of marine animal deaths involving propeller blade strikes are reported to demonstrate characteristic features of such cases and diagnostic difficulties that may occur. Case 1: A juvenile New Zealand fur seal (Arctocephalus forsteri) suffered two parallel linear incised wounds of the flank and died following small intestinal herniation. Case 2: An Indo-Pacific bottlenose dolphin neonate (Tursiops aduncus) died from a deeply incised wound of the left side of the head with shattering of the skull and laceration of the underlying brain.Case 3: An adult female Indo-Pacific bottlenose dolphin (T. aduncus) died from two parallel chop wounds to the torso with opening of the thoracic and abdominal cavities with fractures of the ribs and vertebrae. Given that some animals may recover, and that the carcasses of those that are killed may simply not be found or reported, it is impossible to provide an estimate of the incidence of this type of injury amongst wild sea mammals. In cases that do come to forensic attention accurate evaluation of the type of injury may potentially have great medicolegal significance. Post-mortem putrefaction and post-mortem feeding by other sea animals may complicate assessments. PMID:22391002

  18. The Great Sumatran Fault Strike-slip Syntaxes in North Sumatra: New Insights From DEM and Fieldwork Data Analyses

    NASA Astrophysics Data System (ADS)

    Fernndez-Blanco, David; Philippon, Mlody

    2014-05-01

    Oblique subduction produces slip partitioning or decoupling, in which underthrusting of the subducting slab accommodates the margin-normal component of slip while a trench-parallel strike-slip fault accommodates margin-parallel slip. This process triggers the individualization of slivers of lithosphere between the trench slope and the large-scale strike-slip fault, that control the location of earthquakes and volcanic eruptions. This tectonic setting is seen in the Sumatran section of the Sunda arc-trench system, in which the Great Sumatran Fault (GSF) acts as the main strike-slip system. The accurate definition of the structure and geometry of the GSF, as well as that of its main splays, allow proper constraints on the relative motion of the fore-arc sliver plate and its internal deformation. We present a detailed structural analysis on the basis of GDEM and outcrop data at the northernmost tip of Sumatra, including the northwest islands (i.e., between 4,5N and 6N). In this area, we identify two main deformation domains along the GSF, in relation to a western and an eastern branch. The GSF's splays form the structural highs bounding the Aceh Basin as well as distinctive offshore strike-slip syntaxes responsible for the formation of the NW Sumatra islands. Fieldwork observations in relation to the western branch of the GSF show strike-slip or oblique-slip motions and roughly N-S main stress indicators. A >500m2 fault plane exposure shows well-preserved calcite crystallizations and slickenlines, which mark a transition from pure strike to oblique-slip during N-S transpression. In the offshore, the Pulau Aceh islands developed as a transpressional system of thrust splays splitting westwards from the NNW-SSE western trending line of the GSF. These top-to-the-north thrusts, which become younger northward, formed by N-S to NE-SW main stresses. A tectonic restoration based on the geometry of the thrust system points to >20% shortening accommodated by pure reverse dip-slip. The eastern branch of the GSF built the Pulau Weh Island, a tens-of-kms scale Riedel system, which principal stress axis is N-S. The GSF eastern branch further bifurcates in Pulau Weh, resulting in the development of two NNW-trending ridges to the sides of the island, which are parallel to the main deformation zone. Synthetic R and P systems, with N and NW orientations, are marked regionally by structural highs. The strike-slip syntaxes and the wide distribution of deformation of and within the Sumatra fore-arc sliver document the delocalization of the GSF system. More than 20% of the strike-slip motion in the GSF is accommodated by pure contraction and similar or larger percentages are expected from associated fault splays and strike-slip systems at oblique angles.

  19. Geometry and kinematics of the Arlar strike-slip fault, SW Qaidam basin, China: New insights from 3-D seismic data

    NASA Astrophysics Data System (ADS)

    Cheng, Xiang; Fu, Suotang; Wang, Haifeng; Yu, Xiangjiang; Cheng, Feng; Liu, Runchao; Du, Wei; Guo, Zhaojie

    2015-02-01

    The right-stepping en-chelon Kunbei fault system, consisting of the Hongliuquan, Arlar, XIII, and Kunbei faults, features importantly in the tectonic evolution of the southwest Qaidam basin. The 3D seismic cross-section interpretation and key horizon similarity attribute analysis show that the NWW-striking Arlar fault is composed of two steeply dipping faults (F1 and F2) in cross-sectional view, and branches eastward into two west-dipping faults (F5 and F6) in map view. The fact that the strata above T2 (the base of the early Miocene Xiayoushashan Formation) become dramatically thinner toward the high points of the Arlar fault suggests an early Miocene initiation (ca. 22.0 Ma) for this fault. As indicated by the windowed amplitude-related attribute maps, the Arlar fault and F5 (one branch of the Arlar fault) have cumulative sinistral offsets of ?8.6-8.7 km and ?5.2-5.4 km, respectively. These considerably greater strike-slip components, in conjunction with the respective maximum true dip-slip displacements of <2.2 km and <1.5 km, convincingly demonstrate that the Arlar fault and F5 are two predominantly left-lateral strike-slip faults. The other faults in the Kunbei fault system are similarly of strike-slip types. This means that the southern boundary of the Qaidam basin is not governed by south- or north-directed thrusting but rather strike-slip faulting, implying that the Qaidam basin is not a foreland basin of the Eastern Kunlun Range. Taking the Altyn Tagh fault into account, the Qaidam basin is essentially a strike-slip superimposed basin developing between two large left-lateral strike-slip faults.

  20. Three-Dimensional Slowness Images of the Upper Crust Beneath the Lucky Strike Hydrothermal Vent Sites

    NASA Astrophysics Data System (ADS)

    Seher, T.; Crawford, W.; Singh, S.; Canales, J. P.; Combier, V.; Cannat, M.; Carton, H.; Dusunur, D.; Escartin, J.; Miranda, M. J.; Pouillet-Erguy, A.

    2005-12-01

    In June-July 2005 we carried out the SISMOMAR cruise, as part of the MOMAR project (Monitoring the Mid-Atlantic Ridge). Within this cruise, we conducted a 3D seismic reflection survey over an 18 km km x 3.8 km area covering both the Lucky Strike volcano and hydrothermal vents field. In order to have a full coverage inside the 3D box, shots continued for 2.25 km on either side of the box and extended out to the median valley bounding faults. To complement the streamer measurements 25 Ocean Bottom Seismometers (OBS) were placed in an 18 km x 18 km area. 11 OBS positions lie inside the 3D box and can be used to determine a very detailed image of the 3D velocity structure beneath the Lucky Strike volcano and hydrothermal vents field. For the 3D box a tuned array of 14 air guns (2600 cubic inches) was fired at an interval of 37.5 m for a total of 39 lines. We will present the first results of the OBS measurements near the Lucky Strike volcano. As a first step towards a joint 3D travel time and slowness (the inverse of velocity at turning depth) tomography, we present the 3D slowness function (latitude, longitude, offset), which can be considered as a 3D brute stack velocity image of the sub-surface (c.f. Barton and Edwards, 1999). The presence of fluid in the upper crust due to hydrothermal circulation should appear as a low velocity anomaly beneath the hydrothermal vents. In the next step the OBS measurements will be used to corroborate the reflection images of layer 2A observed in the streamer data for the 3D box. The OBS inside the 3D box recorded turning ray arrivals from the upper crust at a very fine sampling interval (37.5 m x 100 m) over a large azimuth. This provides the unique opportunity for jointly inverting travel time and slowness. Hence the measurements contain information on local gradients and should provide a very detailed velocity model of the subsurface, including information on hydrothermal systems and a possilbe anisotropy (e.g. Cherret and Singh, 1999). References: P. Barton, R. Edwards: Velocity imaging by tau-p transformation, LITHOS Science Report, 1999, 1, 67-75. A. Cherrett, S. Singh: 3D anisotropic models from multi-component data, LITHOS Science Report, 1999, 1, 29-34.

  1. Along-strike and down-dip variations in dcollement physical properties relative to input parameters

    NASA Astrophysics Data System (ADS)

    Wilson, D. J.; McNeill, L. C.; Henstock, T.; Westbrook, G. K.; Bangs, N. L.; Tobin, H. J.; Moore, G. F.; Pickering, K. T.; Saffer, D. M.; Bell, R. E.; Sutherland, R.; Henrys, S. A.

    2013-12-01

    Understanding the controls on dcollement evolution and its impact on seismogenic behaviour is inherently complex due to the lateral variations in material composition, plate and prism structure and the dynamics of the system. Dcollement physical properties gained from core, log and in situ measurements and from experiments can be mapped laterally using reflection coefficients calculated from seismic reflection data. However, independent seismic processing often optimises the structural image of the subsurface at the cost of distorting the amplitudes of the reflections, limiting mapping of physical properties to single lines or 3D volumes. Here we present a method for calculating dcollement reflection amplitudes using unstacked seismic data; we apply this to near-offset traces to determine reflection coefficients, but it could be extended to determine amplitude versus angle responses. Our method can be applied to data from independent acquisitions and produces results that are comparable to previous investigations targeting single datasets. At the Lesser Antilles where ~80 Ma lithosphere is subducted at ~2 cm yr-1, basement ridges act as barriers to trench-parallel sediment transport, dividing thick incoming sediments to the south (up to 7-8 km) from thin incoming sediments to the north (<1 km). At Nankai, where <40 Ma lithosphere is subducted at ~5 cm yr-1 the basement topography controls the along-strike variation in sediment thickness from a maximum of 2 km to <0.5 km. Other parameters recorded along-strike include: subduction obliquity, prism width and taper, thrust fault dip and spacing, position of the dcollement and ratio of net accretion. We observe both along-strike and down-dip variations in the calculated reflection coefficient, and hence physical properties, of the dcollement at both the Lesser Antilles and Nankai that can be compared to the changing subduction parameters. We intend to expand the application of this method to the Cascadia, Hikurangi and Sumatra margins in order to make first-order, global comparisons between dcollement reflectivity, evolution of physical properties, subduction parameters and where available, seismogenic behaviour.

  2. A tectonic model for the Tertiary evolution of strike slip faults and rift basins in SE Asia

    NASA Astrophysics Data System (ADS)

    Morley, C. K.

    2002-04-01

    Models for the Tertiary evolution of SE Asia fall into two main types: a pure escape tectonics model with no proto-South China Sea, and subduction of proto-South China Sea oceanic crust beneath Borneo. A related problem is which, if any, of the main strike-slip faults (Mae Ping, Three Pagodas and Aliao Shan-Red River (ASRR)) cross Sundaland to the NW Borneo margin to facilitate continental extrusion? Recent results investigating strike-slip faults, rift basins, and metamorphic core complexes are reviewed and a revised tectonic model for SE Asia proposed. Key points of the new model include: (1) The ASRR shear zone was mainly active in the Eocene-Oligocene in order to link with extension in the South China Sea. The ASRR was less active during the Miocene (tens of kilometres of sinistral displacement), with minor amounts of South China Sea spreading centre extension transferred to the ASRR shear zone. (2) At least three important regions of metamorphic core complex development affected Indochina from the Oligocene-Miocene (Mogok gneiss belt; Doi Inthanon and Doi Suthep; around the ASRR shear zone). Hence, Paleogene crustal thickening, buoyancy-driven crustal collapse, and lower crustal flow are important elements of the Tertiary evolution of Indochina. (3) Subduction of a proto-South China Sea oceanic crust during the Eocene-Early Miocene is necessary to explain the geological evolution of NW Borneo and must be built into any model for the region. (4) The Eocene-Oligocene collision of NE India with Burma activated extrusion tectonics along the Three Pagodas, Mae Ping, Ranong and Klong Marui faults and right lateral motion along the Sumatran subduction zone. (5) The only strike-slip fault link to the NW Borneo margin occurred along the trend of the ASRR fault system, which passes along strike into a right lateral transform system including the Baram line.

  3. Paleogene tectonics and forearc strike-slip faulting: southern Chile

    SciTech Connect

    Leslie, R.B.; Cande, S.C.

    1985-01-01

    Several lines of evidence suggest that highly oblique Nazca-South America convergence during the middle to late Paleogene resulted in the development of a dextral strike-slip fault landward of the Chile trench. The Linquine-Ofqui fault (LOF) is nearly 1000 km long and trends approximately N10/sup 0/E between 39/sup 0/S and 47/sup 0/S. It consists of several fault strands with the dominant strand represented by a mylonitic zone approximately 3 km wide. Preliminary field mapping (Herve, 1984) indicates seaward trending splay faults that can be projected offshore in the vicinity of two large embayments along the Chile margin. The Golfo de Guafo embayment occurs between 43/sup 0/S and 44/sup 0/S and is approx.40 km wide in the N-S direction. The Golfo de Penas embayment is approx.75 km wide in the N-S direction and occurs between 47/sup 0/S and 48/sup 0/S at the southern end of the LOF. The authors suggest that these embayments are a consequence of NE-SW extension due to movement on splay faults of the LOF system during the middle to late Paleogene. Convergence during this time was highly oblique. Movement decreased on the northern portion of the LOF prior to a decrease in movement on the southern end. Radiometric dates on rocks from the fault zone (Herve, 1984) provide constraints on the timing of movement along the fault. Marine geophysical data allow you to map the structures in these embayments which support the model of dextral shear along the LOF. Reactivation of the LOF may have occurred 6 Ma when a segment of the actively spreading Chile ridge was subducted at the Chile trench adjacent to the Golfo de Penas.

  4. Assessment of performing an MST strike in Tank 21H

    SciTech Connect

    Poirier, Michael R.

    2014-09-29

    Previous Savannah River National Laboratory (SRNL) tank mixing studies performed for the Small Column Ion Exchange (SCIX) project have shown that 3 Submersible Mixer Pumps (SMPs) installed in Tank 41 are sufficient to support actinide removal by MST sorption as well as subsequent resuspension and removal of settled solids. Savannah River Remediation (SRR) is pursuing MST addition into Tank 21 as part of the Large Tank Strike (LTS) project. The preliminary scope for LTS involves the use of three standard slurry pumps (installed in N, SE, and SW risers) in a Type IV tank. Due to the differences in tank size, internal interferences, and pump design, a separate mixing evaluation is required to determine if the proposed configuration will allow for MST suspension and strontium and actinide sorption. The author performed the analysis by reviewing drawings for Tank 21 [W231023] and determining the required cleaning radius or zone of influence for the pumps. This requirement was compared with previous pilot-scale MST suspension data collected for SCIX that determined the cleaning radius, or zone of influence, as a function of pump operating parameters. The author also reviewed a previous Tank 50 mixing analysis that examined the ability of standard slurry pumps to suspend sludge particles. Based on a review of the pilot-scale SCIX mixing tests and Tank 50 pump operating experience, three standard slurry pumps should be able to suspend sludge and MST to effectively sorb strontium and actinides onto the MST. Using the SCIX data requires an assumption about the impact of cooling coils on slurry pump mixing. The basis for this assumption is described in this report. Using the Tank 50 operating experience shows three standard slurry pumps should be able to suspend solids if the shear strength of the settled solids is less than 160 Pa. Because Tank 21 does not contain cooling coils, the shear strength could be larger.

  5. Tipping Points

    NASA Astrophysics Data System (ADS)

    Hansen, J.

    2007-12-01

    A climate tipping point, at least as I have used the phrase, refers to a situation in which a changing climate forcing has reached a point such that little additional forcing (or global temperature change) is needed to cause large, relatively rapid, climate change. Present examples include potential loss of all Arctic sea ice and instability of the West Antarctic and Greenland ice sheets. Tipping points are characterized by ready feedbacks that amplify the effect of forcings. The notion that these may be runaway feedbacks is a misconception. However, present "unrealized" global warming, due to the climate system's thermal inertia, exacerbates the difficulty of avoiding global warming tipping points. I argue that prompt efforts to slow CO2 emissions and absolutely reduce non-CO2 forcings are both essential if we are to avoid tipping points that would be disastrous for humanity and creation, the planet as civilization knows it.

  6. Experimental and numerical study of a bird strike against a windshield

    NASA Astrophysics Data System (ADS)

    Plassard, Fabien; Hereil, Pierre-Louis; Joseph, Pierric; Mespoulet, Jrme

    2015-09-01

    This paper describes a bird strike study performed at THIOT-INGENIERIE laboratory. For aeronautic requirements, the 220 mm version of the gas gun TITAN is used to perform bird strike on instrumented structures. This paper shows a bird strike on a polycarbonate windshield instrumented with high speed cameras, velocity and force sensors. A crossed work with numerical simulation has been performed to design target support and diagnostic tools. It permits also to demonstrate reliability of the numerical tools.

  7. Along-Strike and Down-Dip Variations in Subduction Zone Slip Deficit: Persistent or Transient? (Invited)

    NASA Astrophysics Data System (ADS)

    Freymueller, J. T.

    2010-12-01

    The pattern of elastic deformation at subduction zones depends on the along-strike and down-dip variation in the slip deficit on the plate interface. The location and magnitude of contractional strain is controlled mainly by the down-dip transition from locked (high slip rate deficit) to creeping (low slip rate deficit) behavior of the interface. In southern Alaska, there are dramatic along-strike variations in the depth of this transition, including segments where the locked region is more than 150-200 km wide and at least one segment that may be creeping continuously at all depths. Is this pattern is persistent over time, or does it vary substantially with time? The along-strike variations appear to be persistent over the geodetic record (only 10-15 years), and also with the record of slip in great subduction earthquakes (decades to centuries). In contrast, variations in the position of the downdip transition are observed over short timescales. A large slow-slip events in the upper Cook Inlet region occurred from 1998-2001, during which part of the interface that previously had been locked began to creep in slow slip. More recently, the opposite situation has occurred in lower Cook Inlet, near the town of Homer. Since approximately 2004, part of the interface that had been creeping has locked, making the locked zone wider than before (but still narrower than in the neighboring segments along strike). Other changes in the pattern of deformation here may have occurred in the mid-1990s, based on sparse data. Perhaps the period mid-1990s through 2004 represented a very long slow slip event, or perhaps the frictional behavior of the interface at the down-dip end of the locked zone is very sensitive to small stress changes.

  8. Strike Four! Do-Over Policies Institutionalize GPA Distortion

    ERIC Educational Resources Information Center

    Marx, Jonathan; Meeler, David

    2013-01-01

    Purpose: The aim of this paper is to illustrate how universities play an institutional role in inflating student grade point averages (GPA) by modifying academic polices such as course withdraw, repeats, and satisfactory/unsatisfactory grade options. Design/methodology/approach: Three research strategies are employed: an examination of eight

  9. Squeezing, Striking, and Vocalizing: Is Number Representation Fundamentally Spatial?

    ERIC Educational Resources Information Center

    Nunez, Rafael; Doan, D.; Nikoulina, Anastasia

    2011-01-01

    Numbers are fundamental entities in mathematics, but their cognitive bases are unclear. Abundant research points to linear space as a natural grounding for number representation. But, is number representation fundamentally spatial? We disentangle number representation from standard number-to-line reporting methods, and compare numerical…

  10. Strike Four! Do-Over Policies Institutionalize GPA Distortion

    ERIC Educational Resources Information Center

    Marx, Jonathan; Meeler, David

    2013-01-01

    Purpose: The aim of this paper is to illustrate how universities play an institutional role in inflating student grade point averages (GPA) by modifying academic polices such as course withdraw, repeats, and satisfactory/unsatisfactory grade options. Design/methodology/approach: Three research strategies are employed: an examination of eight…

  11. Squeezing, Striking, and Vocalizing: Is Number Representation Fundamentally Spatial?

    ERIC Educational Resources Information Center

    Nunez, Rafael; Doan, D.; Nikoulina, Anastasia

    2011-01-01

    Numbers are fundamental entities in mathematics, but their cognitive bases are unclear. Abundant research points to linear space as a natural grounding for number representation. But, is number representation fundamentally spatial? We disentangle number representation from standard number-to-line reporting methods, and compare numerical

  12. Towards one trillion positions

    NASA Astrophysics Data System (ADS)

    Haist, Tobias; Gronle, Marc; Bui, Duc Anh; Jiang, Bofan; Pruss, Christof; Schaal, Frederik; Osten, Wolfgang

    2015-05-01

    How accurately can you determine positions using a non-expensive imaging system? We demonstrate a system, that has the potential to achieve position detections over a large measurement field (200 x 200 mm) for one million times one million 2D positions. Non-expensive telecentric imaging of the large object field is achieved using a large diffractive front element in combination with two small off-the-shelf lenses. The position measurement itself is considerably improved using a simple replication technique: the point to be measured is replicated N-times and the centers of gravity of the N points are averaged. By this approach discretization errors and camera noise are reduced by the square root of the number of points. We describe the system, discuss the error model and show experimental results for the DOE-based telecentric imaging and the position detection sensing.

  13. Pre/post-strike atmospheric assessment system (PAAS)

    SciTech Connect

    Peglow, S. G., LLNL; Molitoris, J. D., LLNL

    1997-02-03

    The Pre/Post-Strike Atmospheric Assessment System was proposed to show the importance of local meteorological conditions in the vicinity of a site suspected of storing or producing toxic agents and demonstrate a technology to measure these conditions, specifically wind fields. The ability to predict the collateral effects resulting from an attack on a facility containing hazardous materials is crucial to conducting effective military operations. Our study approach utilized a combination of field measurements with dispersion modeling to better understand which variables in terrain and weather were most important to collateral damage predictions. To develop the PAAS wind-sensing technology, we utilized a combination of emergent and available technology from micro-Doppler and highly coherent laser systems. The method used for wind sensing is to probe the atmosphere with a highly coherent laser beam. As the beam probes, light is back-scattered from particles entrained in the air to the lidar transceiver and detected by the instrument. Any motion of the aerosols with a component along the beam axis leads to a Doppler shift of the received light. Scanning in a conical fashion about the zenith results in a more accurate and two-dimensional measurement of the wind velocity. The major milestones in the benchtop system development were to verify the design by demonstrating the technique in the laboratory, then scale the design down to a size consistent with a demonstrator unit which could be built to take data in the field. The micro-Doppler heterodyne system we developed determines absolute motion by optically mixing a reference beam with the return signal and has shown motion sensitivity to better than 1 cm/s. This report describes the rationale, technical approach and laboratory testing undertaken to demonstrate the feasibility and utility of a system to provide local meteorological data and predict atmospheric particulate motion. The work described herein was funded by the Laboratory Science and Technology Office as a part of the 1996 Laboratory Directed Research and Development Program at Lawrence Livermore National Laboratory.

  14. National Security and Civil Liberty: Striking the Balance

    ERIC Educational Resources Information Center

    Lopach, James J.; Luckowski, Jean A.

    2006-01-01

    After September 11, 2001, the Bush administration initiated large-scale electronic surveillance within the United States to gather intelligence to protect citizens from terrorists. Media commentary, public reaction, and classroom practices regarding this program have tended toward either-or positions: either for presidential power and national…

  15. National Security and Civil Liberty: Striking the Balance

    ERIC Educational Resources Information Center

    Lopach, James J.; Luckowski, Jean A.

    2006-01-01

    After September 11, 2001, the Bush administration initiated large-scale electronic surveillance within the United States to gather intelligence to protect citizens from terrorists. Media commentary, public reaction, and classroom practices regarding this program have tended toward either-or positions: either for presidential power and national

  16. Factors affecting defensive strike behavior in Brown Treesnakes (Boiga irregularis) provoked by humans

    USGS Publications Warehouse

    Spencer, McKayka M.; Lardner, Bjorn; Mazurek, M.J.; Reed, Robert N.

    2015-01-01

    Striking is a typical antipredator defense exhibited by many species of snakes. While trapping Brown Treesnakes (Boiga irregularis) on Guam, we observed that snakes most frequently struck at an approaching person at a site where snakes had been trapped, marked, and handled in the past. Using a combination of between-sites and within-site comparisons, we assessed if the propensity to strike was correlated with capture histories (both recent and long-term), snake size, body condition (a proxy to nutritional stress), sex, or tail condition (broken or intact), while controlling for confounding variables. We confirmed that propensity to strike was higher at the site where we had been conducting capture-mark-recapture for several years. However, we were unable to demonstrate a correlation between striking tendencies and individual recent or long-term capture histories. The only morphological covariate that had an effect on strike propensity was sex, with females striking more often than males. After removing the site effect from our model, we found that snakes missing parts of their tails were more likely to strike than snakes with intact tails. We have yet to identify the factor(s) that cause the pronounced difference across sites in snake propensity to strike, and data from additional sites might help elucidate any geographical patterns.

  17. Batter's Choice: Lessons for Teaching Tactics in a Modified Striking/Fielding Game

    ERIC Educational Resources Information Center

    Sinclair, Christina

    2004-01-01

    When played in their standard form, striking/fielding games are often a favorite among elementary students; yet they allow for only limited participation, which is contradictory to quality physical education. This article presents a sequence of lessons leading to Batter's Choice, a modified striking/fielding game, designed to maximize the

  18. Picket Fencing: Amid Fewer Strikes, Some See Waning Sympathy for Educators

    ERIC Educational Resources Information Center

    Sack, Joetta L.

    2006-01-01

    Once as familiar in the back-to-school ritual as falling leaves, teacher strikes seem headed for a winter freeze. According to the nation's largest teacher's union, about 15 of the National Education Association's (NEA) 14,000 local affiliates have gone on strike since the start of this school year. In Pennsylvania--a traditional union

  19. Expert Anticipatory Skill in Striking Sports: A Review and a Model

    ERIC Educational Resources Information Center

    Muller, Sean; Abernethy, Bruce

    2012-01-01

    Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this paper, we provide a review of the empirical evidence regarding expert interception in striking sports and propose a

  20. Batter's Choice: Lessons for Teaching Tactics in a Modified Striking/Fielding Game

    ERIC Educational Resources Information Center

    Sinclair, Christina

    2004-01-01

    When played in their standard form, striking/fielding games are often a favorite among elementary students; yet they allow for only limited participation, which is contradictory to quality physical education. This article presents a sequence of lessons leading to Batter's Choice, a modified striking/fielding game, designed to maximize the…

  1. Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya

    PubMed Central

    Lieberman, Daniel E.; Castillo, Eric R.; Otarola-Castillo, Erik; Sang, Meshack K.; Sigei, Timothy K.; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

    2015-01-01

    Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces. PMID:26154285

  2. Labor Conflict on the National Stage: Metaphoric Lenses in Israel's Teachers' Strike

    ERIC Educational Resources Information Center

    Shenkar, Miriam; Shenkar, Oded

    2011-01-01

    Teachers often embed their labor demands within a broader context to claim high moral ground and build community support. We analyze a recent teachers' strike in Israel, looking at how the strike played out in a country where the challenges of globalization collided with a socialist legacy in the face of an existential threat. The analysis reveals

  3. Many-Body Localization in One Dimension as a Dynamical Renormalization Group Fixed Point

    NASA Astrophysics Data System (ADS)

    Vosk, Ronen; Altman, Ehud

    2013-02-01

    We formulate a dynamical real space renormalization group (RG) approach to describe the time evolution of a random spin-1/2 chain, or interacting fermions, initialized in a state with fixed particle positions. Within this approach we identify a many-body localized state of the chain as a dynamical infinite randomness fixed point. Near this fixed point our method becomes asymptotically exact, allowing analytic calculation of time dependent quantities. In particular, we explain the striking universal features in the growth of the entanglement seen in recent numerical simulations: unbounded logarithmic growth delayed by a time inversely proportional to the interaction strength. This is in striking contrast to the much slower entropy growth as log?log?t found for noninteracting fermions with bond disorder. Nonetheless, even the interacting system does not thermalize in the long time limit. We attribute this to an infinite set of approximate integrals of motion revealed in the course of the RG flow, which become asymptotically exact conservation laws at the fixed point. Hence we identify the many-body localized state with an emergent generalized Gibbs ensemble.

  4. Leap and strike kinetics of an acoustically hunting barn owl (Tyto alba)

    PubMed Central

    Usherwood, James R.; Sparkes, Emily L.; Weller, Renate

    2014-01-01

    Barn owls are effective hunters of small rodents. One hunting technique is a leap from the ground followed by a brief flight and a plummeting strike onto an acoustically targeted and potentially entirely hidden prey. We used forceplate measurements to derive kinetics of the leap and strike. Leaping performance was similar to reported values for guinea fowl. This is likely achieved despite the owl's considerably smaller size because of its relatively long legs and use of wing upstroke. Strikes appear deliberately forceful: impulses could have been spread over larger periods during greater deflections of the centre of mass, as observed in leaping and an alighting landing measurement. The strike, despite forces around 150 times that of a mouse body weight, is not thought to be crucial to the kill; rather, forceful strikes may function primarily to enable rapid penetration of leaf litter or snow cover, allowing grasping of hidden prey. PMID:24948629

  5. Leap and strike kinetics of an acoustically 'hunting' barn owl (Tyto alba).

    PubMed

    Usherwood, James R; Sparkes, Emily L; Weller, Renate

    2014-09-01

    Barn owls are effective hunters of small rodents. One hunting technique is a leap from the ground followed by a brief flight and a plummeting 'strike' onto an acoustically targeted - and potentially entirely hidden - prey. We used forceplate measurements to derive kinetics of the leap and strike. Leaping performance was similar to reported values for guinea fowl. This is likely achieved despite the owl's considerably smaller size because of its relatively long legs and use of wing upstroke. Strikes appear deliberately forceful: impulses could have been spread over larger periods during greater deflections of the centre of mass, as observed in leaping and an alighting landing measurement. The strike, despite forces around 150 times that of a mouse body weight, is not thought to be crucial to the kill; rather, forceful strikes may function primarily to enable rapid penetration of leaf litter or snow cover, allowing grasping of hidden prey. PMID:24948629

  6. Sulfate levels in the southwest during the 1980 copper smelter strike

    SciTech Connect

    Eldred, R.A.; Ashbaugh, L.L.; Cahill, T.A.; Flocchini, R.G.; Pitchford, M.L.

    1983-02-01

    During the summer of 1980, most of the copper smelters in southern Arizona, New Mexico, and northwestern Texas were shut down by a strike. Particulate concentrations were measured at twelve remote sites in the region from August 1979 though September 1981. This paper compares the mean and maximum sulfate concentrations during the strike summer with those of the summers of 1979 and 1981. Comparisons were limited to the summer periods because of the large seasonal variation in the average conversion rate of sulfur dioxide to sulfate. During the strike summer, the mean sulfate concentrations throughout the region were approximately 1 ..mu..g/m/sup 3/. At the sites between 100 km and 600 km from the smelters, the mean and maximum sulfate concentrations during the non-strike summers were approximately twice the corresponding levels during the strike period. At the sites within 100 km, the mean levels in 1979 and 1981 were around three times those in 1980.

  7. Automatic resolution of the three-points geological problem

    NASA Astrophysics Data System (ADS)

    Martinez-Torres, Luis M.; Lopetegui, Ane; Eguiluz, Luis

    2012-05-01

    The problem of three points, or 3P problem, is the basic geometrical reference of numerous geological structures. We propose a simple Microsoft Excel spreadsheet program that determines from three georeferenced points the strike and dip of the plane that contains them. Practical examples showing the application in Google Earth and LIDAR data are presented.

  8. Along-strike sequence stratigraphy across the Cretaceous shallow marine to coastal-plain transition, Wasatch Plateau, Utah, U.S.A.

    NASA Astrophysics Data System (ADS)

    Gani, M. Royhan; Ranson, Andrew; Cross, David B.; Hampson, Gary J.; Gani, Nahid D.; Sahoo, Hiranya

    2015-07-01

    Current sequence stratigraphic models deal with stratal packages almost exclusively along depositional-dip. A high-resolution outcrop example detailing sequence stratigraphic architecture along depositional-strike is largely lacking. This outcrop study provides a detailed sequence stratigraphic correlation along depositional-strike for a length of ~ 50 km. Moreover, this study focuses on the facies and stratigraphic relationships particularly at the very transition between coeval marine and nonmarine strata, which is relatively underdocumented. Within the Mesaverde Group of central and eastern Utah, the Upper Cretaceous shallow-marine Star Point Sandstone and paralic Blackhawk Formation are relatively well studied along depositional-dip in the Book Cliffs, but the nature of their spatio-temporal transition particularly along depositional-strike in the NNE-SSW trending Wasatch Plateau remains poorly documented. Facies-scale to stratigraphic-scale data were gathered from ten outcrop "windows" along the eastern margin of the Wasatch Plateau. The vertical and lateral transition between marine and nonmarine strata varies in complexity within the study area. In the southern part of the study area near the central Wasatch Plateau, the shallow-marine Star Point Sandstone passes stratigraphically upward into the nonmarine Blackhawk Formation in one simple transition without any intercalation of marine and nonmarine strata. In the northern part of the study area, however, where the Star Point Sandstone to Blackhawk Formation transition is complex, aggradationally stacked shallow-marine sandbodies (i.e., parasequences) taper and completely pinch-out within coastal-plain mudstones in a paleo-landward direction over short distances (< 1 km), representing potential stratigraphic traps. These marine sandbodies are intercalated with coeval nonmarine strata within the Blackhawk Formation. Fourth-order sequence boundaries and flooding surfaces were correlated along the lower Campanian depositional-strike. The results reveal along-strike undulations in the early Campanian depositional topography, which was characterized by alternating incised valleys, interfluvial topographic highs with mature soil development, and shoreline embayments. In particular, the variable along-strike transition-complexity from shallow-marine to coastal-plain strata is the result of differential tectonic subsidence, where the transition-complexity increases and the stacking pattern is more aggradational towards an early Campanian depocenter in the north of the study area. This study reveals that differential subsidence is the key in controlling along-strike variability of sequence stratigraphy and that correlation of sequence stratigraphic surfaces are far more challenging in nonmarine strata than in adjacent marine strata.

  9. Positive Psychology

    ERIC Educational Resources Information Center

    Peterson, Christopher

    2009-01-01

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

  10. The Lagrange Points

    ERIC Educational Resources Information Center

    Lovell, M.S.

    2007-01-01

    This paper presents a derivation of all five Lagrange points by methods accessible to sixth-form students, and provides a further opportunity to match Newtonian gravity with centripetal force. The predictive powers of good scientific theories are also discussed with regard to the philosophy of science. Methods for calculating the positions of the…

  11. Optical Pointing Sensor

    NASA Technical Reports Server (NTRS)

    Shields, Joel F.; Metz, Brandon C.

    2010-01-01

    The optical pointing sensor provides a means of directly measuring the relative positions of JPL s Formation Control Testbed (FCT) vehicles without communication. This innovation is a steerable infrared (IR) rangefinder that gives measurements in terms of range and bearing to a passive retroreflector.

  12. The Lagrange Points

    ERIC Educational Resources Information Center

    Lovell, M.S.

    2007-01-01

    This paper presents a derivation of all five Lagrange points by methods accessible to sixth-form students, and provides a further opportunity to match Newtonian gravity with centripetal force. The predictive powers of good scientific theories are also discussed with regard to the philosophy of science. Methods for calculating the positions of the

  13. Positive Functions of Emotions in Achievement Sports

    ERIC Educational Resources Information Center

    Puig, Nuria; Vilanova, Anna

    2011-01-01

    This article presents the results of two research projects on the emotions of men engaged in achievement outdoor sports. The conditions were analyzed under which emotions carry out positive functions. The question strikes us as a fundamental one, because it is of crucial importance when it comes to increasing sportspeople's success. The

  14. Inversion of Acoustic and Electromagnetic Recordings for Mapping Current Flow in Lightning Strikes

    NASA Astrophysics Data System (ADS)

    Anderson, J.; Johnson, J.; Arechiga, R. O.; Thomas, R. J.

    2012-12-01

    Acoustic recordings can be used to map current-carrying conduits in lightning strikes. Unlike stepped leaders, whose very high frequency (VHF) radio emissions have short (meter-scale) wavelengths and can be located by lightning-mapping arrays, current pulses emit longer (kilometer-scale) waves and cannot be mapped precisely by electromagnetic observations alone. While current pulses are constrained to conductive channels created by stepped leaders, these leaders often branch as they propagate, and most branches fail to carry current. Here, we present a method to use thunder recordings to map current pulses, and we apply it to acoustic and VHF data recorded in 2009 in the Magdalena mountains in central New Mexico, USA. Thunder is produced by rapid heating and expansion of the atmosphere along conductive channels in response to current flow, and therefore can be used to recover the geometry of the current-carrying channel. Toward this goal, we use VHF pulse maps to identify candidate conductive channels where we treat each channel as a superposition of finely-spaced acoustic point sources. We apply ray tracing in variable atmospheric structures to forward model the thunder that our microphone network would record for each candidate channel. Because multiple channels could potentially carry current, a non-linear inversion is performed to determine the acoustic source strength of each channel. For each combination of acoustic source strengths, synthetic thunder is modeled as a superposition of thunder signals produced by each channel, and a power envelope of this stack is then calculated. The inversion iteratively minimizes the misfit between power envelopes of recorded and modeled thunder. Because the atmospheric sound speed structure through which the waves propagate during these events is unknown, we repeat the procedure on many plausible atmospheres to find an optimal fit. We then determine the candidate channel, or channels, that minimizes residuals between synthetic and acoustic recordings. We demonstrate the usefulness of this method on both intracloud and cloud-to-ground strikes, and discuss factors affecting our ability to replicate recorded thunder.

  15. Symphyotrichum ericoides populations from seleniferous and nonseleniferous soil display striking variation in selenium accumulation.

    PubMed

    El Mehdawi, Ali F; Paschke, Mark W; Pilon-Smits, Elizabeth A H

    2015-04-01

    Symphyotrichum ericoides (Asteraceae) from naturally seleniferous habitat (Pine Ridge) was shown previously to have selenium (Se) hyperaccumulator properties in field and glasshouse studies, and to benefit from Se through protection from herbivory. To investigate whether Se hyperaccumulation is ubiquitous in S.ericoides or restricted to seleniferous soils, the S.ericoides Pine Ridge (PR) population was compared with the nearby Cloudy Pass (CP) population from nonseleniferous soil. The S.ericoidesPR and CP populations were strikingly physiologically different: in a common garden experiment, PR plants accumulated up to 40-fold higher Se concentrations than CP plants and had 10-fold higher Se:sulfur (S) ratios. Moreover, roots of S.ericoidesPR plants showed directional growth toward selenate, while CP roots did not. Growth of both accessions responded positively to Se. Each accession grew best on its own soil. Rhizosphere soil inoculum from the S.ericoidesPR population stimulated plant growth and Se accumulation in both S.ericoidesPR and S.ericoidesCP plants, on both PR and CP soils. While the S.ericoidesPR population hyperaccumulates Se, the nearby CP population does not. The capacity of S.ericoidesPR plants to hyperaccumulate Se appears to be a local phenomenon that is restricted to seleniferous soil. Mutualistic rhizosphere microbes of the S.ericoidesPR population may contribute to the hyperaccumulation phenotype. PMID:25406635

  16. Relationships between strike-slip movement and fold trends in thin-skinned tectonics: Analogue models

    NASA Astrophysics Data System (ADS)

    Odonne, F.; Costa, E.

    1993-12-01

    In thin-skinned tectonics, a sediment cover has been sheared off from an underlying basement. In many cases, such detachments are located in salt horizons. During deformation, faults and narrow anticlinal folds can develop in the cover. Analogue models show that fold axis patterns are related to the compression direction and to the position and shape of the faults. In each model, a multilayer made of paraffin wax and grease represents the cover sliding over a rigid basement made of plexiglass. In each of the three experiments a fault is cut before deformation. This fault may be located: in the basement; in the cover, with a limited length; or in the cover, with an unlimited length. The fold axis patterns are very heterogeneous around a limited-length fault in the multilayer where the fold axes deviation can reach 90 around the fault tips. They are quite homogeneous around an unlimited-length fault, irrespective of its location. An unlimited-length fault mainly induces a slight deviation of the fold axes due to strike-slip movement. The detachment horizon reduces the transmission of stresses from the basement and in such cases, the final deformation is very sensitive to local heterogeneities inside the overriding multilayer.

  17. First measurements of the ion energy distribution at the divertor strike point during DIII-D disruptions

    SciTech Connect

    Parks, P.B.; Brooks, N.H.; West, W.P.; Wong, C.P.C.; Bastasz, R.; Wampler, W.R.; Whyte, D.

    1996-03-01

    Plasma disruptions are a serious concern in tokamak design because of the high impulsive heat loads which can cause strong erosion of divertor materials due to enhanced sputtering, or melting/ablation in the most severe cases. Predictions of net erosion rates and hence component lifetimes are very difficult and are highly dependent on the plasma conditions over the divertor target. It is therefore necessary to characterize the properties of the scrape-off plasma near the divertor target plate under these special conditions. Here, plasma/wall interaction studies are being carried out using the Divertor Materials Exposure System (DiMES) on DIII-D. The objective of the experiment is to determine the kinetic energy and flux of deuterium ions reaching the divertor target during argon-induced radiative disruptions. The experiment utilizes a special slotted ion analyzer mounted over a Si sample to collect the fast charge-exchange (CX) deuterium neutrals emitted within the recycled cold neutral layer (CNL) which serves as a CX target for the incident ions. A theoretical interpretation of the experiment reveals a strong forward pitch-angle dependence in the approaching ion distribution function. The depth distribution of the trapped D in the Si sample was measured using low-energy direct recoil spectroscopy. Comparison with the TRIM code using monoenergetic ions indicated that the best fit to the data was obtained for an ion energy of 100 eV. An estimate of the CNL thickness {integral}nd{ell} indicates that during disruptions the CNL cushion is thick enough to reduce the local ion heat load by {approximately}30% due to CX refluxing.

  18. Constructing a Temporal and Spatial Record of Lightning Strikes in Arctic Alaska: Discerning between increased strike frequency and increased detection capability

    NASA Astrophysics Data System (ADS)

    Crosby, B. T.

    2010-12-01

    Previous published explorations of the relation between contemporary wildfire and lightning in Alaska have focused largely on the central boreal forest. Following the long duration (3 month), large extent (100,000 ha) 2007 Anaktuvuk River Fire on the North Slope of Alaska, some have questioned whether changes in summertime temperatures in that region have affected convective storms and the frequency of lightning strikes. Investigations of strike frequency rely on sensor networks that have progressively increased their detection capabilities by the addition of new stations or the installations of more sensitive instrumentation. Distinguishing whether North Slope lightning strikes have become more frequent requires isolating the bias of the increased detection capability of the Alaska Lightning Detection System (ALDS) between the years 1988 and 2010. Numerous methods are applied to remove this bias. Attempts are made to use only records collected from a select few legacy stations that were operational during the duration of the record. Given the history of network improvements, I have also sought to identify step-wise increases in detection and calibrate past records to reflect modern detection capabilities. Regardless of the method to remove the bias, it is clear that the timing, frequency and location of strikes have changed over the 22 years of record. I use the center time analysis (the date when half of the annual strikes have occurred) to explore if lightning is persisting later into the summer season when the tundra is drier and more apt to burn. Though the data from the whole state show a weak trend toward an earlier center time, the North Slope data lack a trend toward either earlier or later center time. It is clear that for most years, the center time is later on the North Slope than for the whole state. Following bias removal, the frequency of strikes has clearly increased starting in the summer of 2002 with the largest number of strikes occurring in 2007. Further comparison of strike frequency and timing with North Slope meteorological conditions will provide insight into the sensitivity of the region to more large magnitude tundra fires. Though vegetation recovery at burned sites appears to be more rapid than anticipated, the thermal disturbance fire generates can have long lasting impacts on active layer dynamics, hillslope stability and the generation and persistence of thermal erosion features.

  19. Basin genesis associated with strike-slip faulting in the Basin and Range, southeastern Nevada

    NASA Astrophysics Data System (ADS)

    Campagna, David J.; Aydin, Atilla

    1994-04-01

    The structural nature of two prominent Basin and Range strike-slip systems, the Lake Mead fault system and the Las Vegas Valley shear zone, are examined using both geological field mapping and geophysical surveys at various scales. The intent of this study is to document deformation directly attributable to strike-slip faulting with an emphasis on basin genesis. Our field study of the Lake Mead fault system reveals a major left step in the system. The stepover results in the genesis of a 2-km-deep pull-apart, the Overton Arm Basin, consistent with the kinematics and mechanics of strike-slip faulting. Having established the origin of the Overton Arm basin as a strike-slip-related pull-apart basin, the geometry of poorly exposed strike-slip systems can be revealed by understanding the related basins along their length. One such system, the Las Vegas Valley shear zone, is shown with the aid of geophysical data to be geographically related to three distinct en echelon basins. When these basins are interpreted as pull-apart basins, the geometry of the Las Vegas Valley shear zone becomes apparent for the first time. We assert that strike-slip faulting in southeastern Nevada is a deformational mechanism that contributes locally to the regional extensional tectonics. Such an interpretation modifies extant models that treat strike-slip faults in rifted terrains as passive lateral boundaries that simply accommodate extension without contributing to the process.

  20. Variation in Foot Strike Patterns during Running among Habitually Barefoot Populations

    PubMed Central

    Hatala, Kevin G.; Dingwall, Heather L.; Wunderlich, Roshna E.; Richmond, Brian G.

    2013-01-01

    Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns. PMID:23326341

  1. Variation in foot strike patterns during running among habitually barefoot populations.

    PubMed

    Hatala, Kevin G; Dingwall, Heather L; Wunderlich, Roshna E; Richmond, Brian G

    2013-01-01

    Endurance running may have a long evolutionary history in the hominin clade but it was not until very recently that humans ran wearing shoes. Research on modern habitually unshod runners has suggested that they utilize a different biomechanical strategy than runners who wear shoes, namely that barefoot runners typically use a forefoot strike in order to avoid generating the high impact forces that would be experienced if they were to strike the ground with their heels first. This finding suggests that our habitually unshod ancestors may have run in a similar way. However, this research was conducted on a single population and we know little about variation in running form among habitually barefoot people, including the effects of running speed, which has been shown to affect strike patterns in shod runners. Here, we present the results of our investigation into the selection of running foot strike patterns among another modern habitually unshod group, the Daasanach of northern Kenya. Data were collected from 38 consenting adults as they ran along a trackway with a plantar pressure pad placed midway along its length. Subjects ran at self-selected endurance running and sprinting speeds. Our data support the hypothesis that a forefoot strike reduces the magnitude of impact loading, but the majority of subjects instead used a rearfoot strike at endurance running speeds. Their percentages of midfoot and forefoot strikes increased significantly with speed. These results indicate that not all habitually barefoot people prefer running with a forefoot strike, and suggest that other factors such as running speed, training level, substrate mechanical properties, running distance, and running frequency, influence the selection of foot strike patterns. PMID:23326341

  2. Nursing Positions

    MedlinePLUS

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

  3. Point-contact spectroscopy of the iron chalcogenide superconductors: interplay between multiband superconductivity and magnetism

    NASA Astrophysics Data System (ADS)

    Park, Wan Kyu; Hunt, C. R.; Arham, H. Z.; Lu, X.; Greene, L. H.; Xu, Z. J.; Wen, J. S.; Lin, Z. W.; Li, Q.; Gu, G.

    2010-03-01

    We report point-contact conductance measurements on the iron chalcogenide superconductors, Fe1+yTe1-xSex. The excess Fe atoms are known to occupy the interstitial sites in the Te-Se plane, affecting the superconductivity as well as the magnetism in this family. For a compound having nominal values of y=0 and x=0.45, a single superconducting transition is observed at 14.2 K. In the superconducting state, BTK-like double peak structures due to Andreev reflection are observed. However, the peak position of different point contacts falls to a wide voltage range, 1.5 -- 4 mV. Additional multiple humps are sometimes observed in a much higher bias voltage range, 8 -- 15 mV. Most strikingly, conductance enhancement persists well above Tc. We will present possible interpretations of these experimental observations in terms of multiband superconductivity and the interplay between superconductivity and magnetism.

  4. Civil helicopter wire strike assessment study. Volume 1: Findings and recommendations

    NASA Technical Reports Server (NTRS)

    Tuomela, C. H.; Brennan, M. F.

    1980-01-01

    Approximately 208 civil helicopter wire strike accidents for a ten year period 1970 to 1979 are analyzed. It is found that 83% of the wire strikes occurred during bright clear weather. Analysis of the accidents is organized under pilot, environment, and machine factors. Methods to reduce the wire strike accident rate are discussed, including detection/warning devices, identification of wire locations prior to flight, wire cutting devices, and implementation of training programs. The benefits to be gained by implementing accident avoidance methods are estimated to be fully justified by reduction in injury and death and reduction of aircraft damage and loss.

  5. The 3D fault and vein architecture of strike-slip releasing- and restraining bends: Evidence from volcanic-centre-relatedmineral deposits

    USGS Publications Warehouse

    Berger, B.R.

    2007-01-01

    High-temperature, volcanic-centre-related hydrothermal systems involve large fluid-flow volumes and are observed to have high discharge rates in the order of 100-400 kg/s. The flows and discharge occur predominantly on networks of critically stressed fractures. The coupling of hydrothermal fluid flow with deformation produces the volumes of veins found in epithermal mineral deposits. Owing to this coupling, veins provide information on the fault-fracture architecture in existence at the time of mineralization. They therefore provide information on the nature of deformation within fault zones, and the relations between different fault sets. The Virginia City and Goldfield mining districts, Nevada, were localized in zones of strike-slip transtension in an Early to Mid-Miocene volcanic belt along the western margin of North America. The Camp Douglas mining area occurs within the same belt, but is localized in a zone of strike-slip transpression. The vein systems in these districts record the spatial evolution of strike-slip extensional and contractional stepovers, as well as geometry of faulting in and adjacent to points along strike-slip faults where displacement has been interrupted and transferred into releasing and restraining stepovers. ?? The Geological Society of London 2007.

  6. The feasibility of inflight measurement of lightning strike parameters

    NASA Technical Reports Server (NTRS)

    Crouch, K. E.; Plumer, J. A.

    1978-01-01

    The appearance of nonmetallic structural materials and microelectronics in aircraft design has resulted in a need for better knowledge of hazardous environments such as lightning and the effects these environments have on the aircraft. This feasibility study was performed to determine the lightning parameters in the greatest need of clarification and the performance requirements of equipment necessary to sense and record these parameters on an instrumented flight research aircraft. It was found that electric field rate of change, lightning currents, and induced voltages in aircraft wiring are the parameters of greatest importance. Flat-plate electric field sensors and resistive current shunts are proposed for electric field and current sensors, to provide direct measurements of these parameters. Six bit analog-to-digital signal conversion at a 5 nanosecond sampling rate, short-term storage of 85000 bits and long term storage of 5 x 10 to the 7th power bits of electric field, current and induced voltage data on the airplane are proposed, with readout and further analysis to be accomplished on the ground. A NASA F-106B was found to be suitable for use as the research aircraft because it has a minimum number of possible lightning attachment points, space for the necessary instrumentation, and appears to meet operational requirements. Safety considerations are also presented.

  7. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

    PubMed

    Kusano, Kristofer D; Gabler, Hampton C

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G's to 0.8 G's while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G's. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% - 50% and avoid 0% - 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%. PMID:21050603

  8. Cenozoic geodynamics of the Ross Sea region, Antarctica: Crustal extension, intraplate strike-slip faulting, and tectonic inheritance

    NASA Astrophysics Data System (ADS)

    Salvini, Francesco; Brancolini, Giuliano; Busetti, Martina; Storti, Fabrizio; Mazzarini, Francesco; Coren, Franco

    1997-11-01

    An integrated study of onshore and offshore geology of the Ross Sea region (namely, Victoria Land, north of Ross Island, and the Ross Sea, Antarctica) has revealed a complex, post-Eocene tectonic framework. Regional NW-SE right-lateral, strike-slip faults are the outstanding feature of this framework and overprint an older Mesozoic extensional event, responsible for formation of N-S basins in the Ross Sea. The Cenozoic framework includes kinematic deformation and reactivation along the NW-SE faults, including formation of pull-apart basins, both positive and negative flower structures, and push-up ridges. N-S extensional faults are well developed between NW-SE faults and indicate E-W extension during the Cenozoic, produced by the NW-SE right-lateral strike-slip motion together with regional crustal extension. NNW-SSE compression, induced by the right-lateral, strike-slip kinematics, is indicated by locally inverted NE-SW faults and basins. The evolution, geometry, and location of the Rennick Graben and the Lanterman Range fit well into this model. Variations in the deformational style across the region can be linked to corresponding variations in the bulk crustal rheology, from brittle behavior in the west, to ductile deformation (at subseismic-scale resolution) near the Eastern Basin. A semibrittle region that favors N-S clustering of Cenozoic magmatic activity lies in between. In this region, Cenozoic volcanoes develop at the intersections of the NW-SE and the major N-S faults. The NW-SE faults cut almost continually from the Ross Sea to East Antarctica through lithospheric sectors with different rheology and thickness. At least two of the NW-SE faults correspond to older Paleozoic terrane boundaries in northern Victoria Land. The NW-SE faults link in the Southern Ocean with major transform faults related to the plate motions of Australia, New Zealand, and Antarctica.

  9. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes

    PubMed Central

    Kusano, Kristofer D.; Gabler, Hampton C.

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G’s to 0.8 G’s while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G’s. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% – 50% and avoid 0% – 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%. PMID:21050603

  10. Fusion of LADAR with SAR for precision strike

    SciTech Connect

    Cress, D.H.; Muguira, M.R.

    1995-03-01

    This paper presents a concept for fusing 3-dimensional image reconnaissance data with LADAR imagery for aim point refinement. The approach is applicable to fixed or quasi-fixed targets. Quasi-fixed targets are targets that are not expected to be moved between the time of reconnaissance and the time of target engagement. The 3-dimensional image data is presumed to come from standoff reconnaissance assets tens to hundreds of kilometers from the target area or acquisitions prior to hostilities. Examples are synthetic aperture radar (SAR) or stereoprocessed satellite imagery. SAR can be used to generate a 3-dimensional map of the surface through processing of data acquired with conventional SAR acquired using two closely spaced, parallel reconnaissance paths, either airborne or satellite based. Alternatively, a specialized airborne SAR having two receiving antennas may be used for data acquisition. The data sets used in this analysis are: (1) LADAR data acquired using a Hughes-Danbury system flown over a portion of Kirtland AFB during the period September 15--16, 1993; (2) two pass interferometric SAR data flown over a terrain-dominated area of Kirtland AFB; (3) 3-dimensional mapping of an urban-dominated area of the Sandia National Laboratories and adjacent cultural area extracted from aerial photography by Vexcel Corporation; (4) LADAR data acquired at Eglin AFB under Wright Laboratory`s Advanced Technology Ladar System (ATLAS) program using a 60 {mu}J, 75 KHz Co{sub 2} laser; and (5) two pass interferometric SAR data generated by Sandia`s STRIP DCS (Data Collection System) radar corresponding to the ATLAS LADAR data. The cultural data set was used in the urban area rather than SAR because high quality interferometric SAR data were not available for the urban-type area.

  11. Summary of 2011 Direct and Nearby Lightning Strikes to Launch Complex 39B, Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    Mata, C.T.; Mata, A.G.

    2012-01-01

    A Lightning Protection System (LPS) was designed and built at Launch Complex 39B (LC39B), at the Kennedy Space Center (KSC), Florida in 2009. This LPS was instrumented with comprehensive meteorological and lightning data acquisition systems that were deployed from late 2010 until mid 2011. The first direct strikes to the LPS were recorded in March of 2011, when a limited number of sensors had been activated. The lightning instrumentation system detected a total of 70 nearby strokes and 19 direct strokes to the LPS, 2 of the 19 direct strokes to the LPS had two simultaneous ground attachment points (in both instances one channel terminated on the LPS and the other on the nearby ground). Additionally, there are more unaccounted nearby strokes seen on video records for which limited data was acquired either due to the distance of the stroke or the settings of the data acquisition system. Instrumentation deployment chronological milestones, a summary of lightning strikes (direct and nearby), high speed video frames, downconductor currents, and dH/dt and dE/dt typical waveforms for direct and nearby strokes are presented.

  12. Strike-dip determination of fractures in drill cores by an astatic-magnetometer

    SciTech Connect

    Hayashi, M.; Furutani, N.

    1982-10-01

    The strike and dip of fractures in drillcores from Well HT-4 drilled in the Hatchobaru geothermal field, Kyushu, Japan, have been determined using an astatic-magnetometer. Since the drill cores consist mainly of younger andesite lavas, the measurements of the declination and inclination of remnant magnetism should yield the strike and dip of the fractures. The results show that they dip generally southward with angles from 40/sup 0/ to 80/sup 0/ (62.5 on the average), and strike NW-SE or NE-SW. The NW-SE trending fractures predominate in the Pleistocene series, which persists at depths shallower than 1000 m, while the NE-SW trending ones occur in the Neogene system at deeper levels, and are considered to be older than the former. The stress field can also be estimated by the strike-dip data and the direction of lineation on a slickenside.

  13. Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation

    PubMed Central

    Soldatini, Cecilia; Albores-Barajas, Yuri Vladimir; Lovato, Tomas; Andreon, Adriano; Torricelli, Patrizia; Montemaggiori, Alessandro; Corsa, Cosimo; Georgalas, Vyron

    2011-01-01

    The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B. PMID:22194950

  14. Asymmetrical valleys created by the geomorphic response of rivers to strike-slip fault

    NASA Astrophysics Data System (ADS)

    Zhang, Ke; Liu, Kaiyu; Yang, Jinchun

    2004-11-01

    Offset fluvial valleys, including rivers beheaded and deflected by strike-slip faults, have long been used to estimate horizontal displacements on the faults. Larger rivers crossing such faults, however, sometimes show either no offset or only a small amount of offset compared to smaller rivers crossing the same faults. The larger rivers with higher erosional rates may widen their valleys asymmetrically downstream of strike-slip faults, rather than being beheaded or deflected. Examples are described from the Yellow River near the NE margin of the Tibetan Plateau. River beheading and asymmetrical widening are two end-members of a fluvial valley's response to strike-slip faulting, whereas deflection is a combination of both. Recognition of the formation of such asymmetrical valleys related to strike-slip faulting will help to understand fault activity better over longer time spans and enable a re-evaluation of many fault histories worldwide.

  15. Expert anticipatory skill in striking sports: a review and a model.

    PubMed

    Mller, Sean; Abernethy, Bruce

    2012-06-01

    Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this papr we provide a review of the empirical evidence regarding expert interception in striking sports and propose a preliminary model of expert anticipation. Central to the review and the model is the notion that the visual information used to guide the sequential phases of the striking action is systematically different between experts and nonexperts. Knowing the factors that contribute to expert anticipation, and how anticipation may guide skilled performance in striking sports, has practical implications for assessment and training across skill levels. PMID:22808703

  16. Strike-slip accommodated core complexes in the Najd fault system, Arabian-Nubian shield

    NASA Astrophysics Data System (ADS)

    Meyer, S. E.; Passchier, C. W.; Abu-Alam, T. S.; Stuewe, K.

    2013-12-01

    Metamorphic core complexes are usually developed as extensional features during crustal thinning in a continental collision zone, such as the Basin and Range and the Aegean Terrane. The Najd fault system in Saudi Arabia is a 2000 km-long and 400 km-wide complex network of crustal-scale strike-slip shear zones in a Neoproterozoic collision zone. Locally, the anastomosing shear zones lead to exhumation of lower crustal segments and represent a new kinematic model for the development of core complexes. We report on two such dome structures: the Qazaz complex in Saudi Arabia and the Hafafit complex in Egypt. The 15-km-wide Qazaz complex is a triangular dome of gently dipping mylonitic foliations within the 140-km-long sinistral strike-slip Qazaz mylonite zone. The gneissic dome consists of high-grade rocks, surrounded by low-grade metasediments and metavolcanics. The main SE trending strike-slip Qazaz shear zone splits southwards into two branches around the gneiss dome: the western branch is continuous with the shallow dipping mylonites of the dome core, without overprinting, and curves by more than 90 degrees eastwards from a NS trending strike slip zone to an EW trending 40 degree south dipping detachment that bounds the gneiss dome to the south. The eastern SE trending sinistral strike slip shear zone branch is slightly younger and transects the central dome fabrics. The gneiss dome appears to have formed along a jog in the strike slip shear zone during 40 km of strike slip motion, which caused local exhumation of lower crustal rocks by 25 km along the detachment. The eastern shear zone branch formed late during exhumation, transacted the gneiss dome and offset the two parts by another 70 km. The Hafafit core complex in Egypt is of similar shape and size to the Qazaz structure, but forms the northern termination of a sinistral strike-slip zone that is at least 100 km in length. This zone may continue into Saudi Arabia as the Ajjaj shear zone for another 100 km. The NW trending strike slip mylonite zone grades into a gently N-dipping detachment to the west which accommodated strike slip by exhumation of high-grade lower crustal rocks. The Qazaz and the Hafafit Domes are similar, mirror-image structures with small differences in the accommodating shear zones. It is likely that this type of strike-slip related oblique core complexes are common in the Arabian Nubian shield, and possibly elsewhere.

  17. The β-Lactams Strike Back: Ceftazidime-Avibactam.

    PubMed

    Zasowski, Evan J; Rybak, Jeffrey M; Rybak, Michael J

    2015-08-01

    Gram-negative resistance has reached a crucial point, with emergence of pathogens resistant to most or all available antibiotics. Ceftazidime-avibactam is a newly approved agent combining ceftazidime and a novel β-lactamase inhibitor with activity against multidrug-resistant gram-negative bacteria. Avibactam has increased potency and expanded spectrum of inhibition of class A and C β-lactamases relative to available β-lactamase inhibitors, including extended-spectrum β-lactamases, AmpC, and Klebsiella pneumoniae carbapenemase (KPC) enzymes. Avibactam expands ceftazidime's spectrum of activity to include many ceftazidime- and carbapenem-resistant Enterobacteriaceae and Pseudomonas aeruginosa. Early clinical data indicate that ceftazidime-avibactam is effective and well tolerated in patients with complicated urinary tract infections (cUTIs) and complicated intraabdominal infections (cIAI). In a phase II trial of patients with cUTIs, ceftazidime-avibactam produced similar rates of clinical and microbiologic success compared with imipenem-cilastatin (70.5% and 71.4% microbiologic success rates, respectively). Likewise, patients receiving ceftazidime-avibactam plus metronidazole in a phase II study of patients with cIAI had similar response rates to those receiving meropenem (91.2% and 93.4% clinical success rates, respectively). Based on available in vitro, in vivo, and phase II trial data, as well as preliminary phase III trial results in ceftazidime-resistant, gram-negative cUTI and cIAI, ceftazidime-avibactam received U.S. Food and Drug Administration approval for treatment of cUTI, including pyelonephritis, and cIAI, in combination with metronidazole, in adult patients with limited or no alternative treatment options. The approved dosage, ceftazidime 2 g-avibactam 0.5 g administered as a 2-hour infusion every 8 hours, was selected based on pharmacodynamic analysis and available clinical data. This dosage is under further investigation in patients with cUTI, cIAI, and nosocomial or ventilator-associated pneumonia. The current body of evidence suggests that ceftazidime-avibactam is a promising addition to our therapeutic armamentarium with potential to answer an urgent unmet medical need. Further data in highly resistant gram-negative infections, particularly those caused by KPC-producing Enterobacteriaceae, are needed. As it is introduced into clinical use, careful stewardship and rational use are essential to preserve ceftazidime-avibactam's potential utility. PMID:26289307

  18. Regional linear cross-strike discontinuities in Western Aphrodite Terra, Venus

    NASA Technical Reports Server (NTRS)

    Crumpler, L. S.; Head, James W., III; Harmon, John K.

    1987-01-01

    Western Aphrodite Terra, Venus, is characterized by a series of parallel linear structural discontinuities 2000-4000 km in length and 100-200 km wide, which strike at high angles to the general topographic trend of the highlands. The detailed characteristics of these features are similar to terrestrial oceanic fracture zones and strike-slip fault zones. Either interpretation implies the presence of large-scale horizontal tectonic movement on Venus.

  19. The Three-Point Problem in the Context of Elementary Vector Analysis.

    ERIC Educational Resources Information Center

    Vacher, Henry Leonard

    1989-01-01

    This article presents a vector-analysis approach to the classical three-point problem in hydrogeology. Problem sets involving strike and dip, and ground water flow including computer programs (in BASIC) for their solution are given. (CW)

  20. Investigation of the relationship between precipitation intensity and lightning strikes in Baden-Wrttemberg

    NASA Astrophysics Data System (ADS)

    Seidel, Jochen; Auer, Hannah; Brdossy, Andrs

    2015-04-01

    Precipitation is highly variable in space and time which imposes problems when this parameter has to be interpolated between stations. Often, auxiliary parameters such as elevation are included in interpolation algorithms, e.g. External Drift Kriging. In this study we investigate the potential of using the information from the occurrence of lightning strikes as additional parameter to improve the regionalisation of precipitation. A dataset of lightning strikes from 2009 to 2012 for the region of Baden-Wrttemberg (Germany) for the summer months June, July and August was analysed and compared with hourly precipitation data from 208 rain gauges. Lightning density maps were used to see whether there are any spatial patterns in lightning strikes in the study area. Furthermore, the rank correlation between the number of lightning strikes in the vicinity of the rain gauges and the precipitation intensity was analysed. We also address the question how the precipitation probability changes when a lighting strike is registered in the vicinity of a gauging station and how often, i.e. during how many hours, this additional information from lightning strikes is available.

  1. Correlates of avian building strikes at a glass faade museum surrounded by avian habitat

    NASA Astrophysics Data System (ADS)

    Kahle, L.; Flannery, M.; Dumbacher, J. P.

    2013-12-01

    Bird window collisions are the second largest anthropogenic cause of bird deaths in the world. Effective mitigation requires an understanding of which birds are most likely to strike, when, and why. Here, we examine five years of avian window strike data from the California Academy of Sciences - a relatively new museum with significant glass faade situated in Golden Gate Park, San Francisco. We examine correlates of window-killed birds, including age, sex, season, and migratory or sedentary tendencies of the birds. We also examine correlates of window kills such as presence of habitat surrounding the building and overall window area. We found that males are almost three times more likely than females to mortally strike windows, and immature birds are three times more abundant than adults in our window kill dataset. Among seasons, strikes were not notably different in spring, summer, and fall; however they were notably reduced in winter. There was no statistical effect of building orientation (north, south, east, or west), and the presence of avian habitat directly adjacent to windows had a minor effect. We also report ongoing studies examining various efforts to reduce window kill (primarily external decals and large electronic window blinds.) We hope that improving our understanding of the causes of the window strikes will help us strategically reduce window strikes.

  2. Site-related differences in gene expression and bacterial densities in the mussel Bathymodiolus azoricus from the Menez Gwen and Lucky Strike deep-sea hydrothermal vent sites.

    PubMed

    Bettencourt, Raul; Rodrigues, Mónica; Barros, Inês; Cerqueira, Teresa; Freitas, Cátia; Costa, Valentina; Pinheiro, Miguel; Egas, Conceição; Santos, Ricardo Serrão

    2014-08-01

    The deep-sea hydrothermal vent mussel Bathymodiolus azoricus is a symbiont bearing bivalve that is found in great abundance at the Menez Gwen and Lucky Strike hydrothermal vent sites and in close vicinity of the Azores region near the Mid-Atlantic Ridge (MAR). The physiological relationships that vent mussels have developed with their physical and chemical environments are likely to influence global gene expression profiles providing thus the means to investigate distinct biological markers predicting the origin of Bathymodiolus sp. irrespectively of their geographical localization. Differences found at gene expression levels, and between fluorescence in situ hybridization (FISH) and 16S rRNA amplicon sequencing results provided experimental evidence for the distinction of both Menez Gwen and Lucky Strike vent mussel individuals based on bacterial and vent mussel gene expression signatures and on the constitutive distribution and relative abundance of endosymbiotic bacteria within gill tissues. Our results confirmed the presence of methanotroph endosymbionts in Menez Gwen vent mussels whereas Lucky Strike specimens seem to harbor a different bacterial morphotype when a methane monooxygenase gene specific probe was used. No qualitative differences could be visualized between Menez Gwen and Lucky Strike individuals when tested with a sulfur-oxidizing-related probe. Quantitative PCR (qPCR) studies revealed different gene expression profiles in both Menez Gwen and Lucky Strike mussel gill tissues for the immune genes selected. Genes encoding transcription factors presented noticeably low levels of fold expression whether in Menez Gwen or Lucky Strike animals whereas the genes encoding effector molecules appeared to have higher levels expression in gill tissues from Menez Gwen animals. The peptidoglycan recognition molecule encoding gene, PGRP, presented the highest level of transcriptional activity among the genes analyzed in Menez Gwen mussel gill tissues, seconded by carcinolectin and thus denoting the relevance of immune recognition molecules in early stage of the immune responses onset. Genes regarded as encoding molecules involved in signaling pathways were consistently expressed in both Menez Gwen and Lucky Strike mussel gill tissues. Remarkably, the immunity-related GTPase encoding gene demonstrated, in Lucky Strike samples, the highest level of expression among the signaling molecule encoding genes tested when expressions levels were compared between Menez Gwen and Lucky Strike animals. A differential expression analysis of bacterial genes between Menez Gwen and Lucky Strike mussels indicated a clear expression signature in the latter animal gill tissues. The bacterial community structure ensued from the 16S rRNA sequencing analyses pointed at an unpredicted conservation of endosymbiont bacterial loads between Menez Gwen and Lucky Strike samples. Taken together, our results support the hypothesis that B. azoricus exhibits different transcriptional statuses while living in distinct hydrothermal vent sites may result in distinct gene expressions because of physico-chemical and/or symbiont densities differences. PMID:24882018

  3. Positive Psychotherapy

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  4. Positive Psychotherapy

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  5. Positioning Agility

    NASA Astrophysics Data System (ADS)

    Oza, Nilay; Abrahamsson, Pekka; Conboy, Kieran

    Agile methods are increasingly adopted by European companies. Academics too are conducting numerous studies on different tenets of agile methods. Companies often feel proud in marketing themselves as ‘agile’. However, the true notion of ‘being agile’ seems to have been overlooked due to lack of positioning of oneself for agility. This raises a call for more research and interactions between academia and the industry. The proposed workshop refers to this call. It will be highly relevant to participants, interested in positioning their company’s agility from organizational, group or project perspectives. The positioning of agility will help companies to better align their agile practices with stakeholder values. Results of the workshop will be shared across participants and they will also have opportunity to continue their work on agile positioning in their companies. At broader level, the work done in this workshop will contribute towards developing Agile Positioning System.

  6. Post-Late Jurassic, pre-late Eocene strike-slip faulting in west-central Utah

    SciTech Connect

    Robinson, J.P.

    1993-04-01

    Two events of strike-slip faulting interpreted to be of Late Mesozoic-Early Tertiary age are recorded in the northern Deep Creek Mountains. These fault systems display principal detachment zones that strike N50W and N84E. Both fault systems are manifested as fault mosaics, locally anastomosing with local duplex formation. They are interpreted to represent first-order structures that operated independently of other strain regimes. A quartz monzonite stock dated 38 Ma displays strong control of the intrusion by the NW-striking faults. That, in addition to cross-cutting relationships between the NW-striking faults and a granodiorite dated 152 Ma place age constraints on the strike-slip faulting. The ENE-striking faults are younger than the NW-striking faults and are interpreted to be older than the quartz monzonite, although this relationship is ambiguous. Strike-separation on the major NW-striking faults is on the order of 3 km. Offsets of similar magnitude or greater are interpreted for the ENE-striking faults, although this remains unquantified. Despite the small area of influence, relatively minor displacements, and broad time frame of occurrence, these faults have some regional significance. If Cretaceous-aged, the strike-slip faults are markedly different than the extensional structures that formed in the internal zone' of the Cordilleran thrust belt. If Tertiary-aged, the strike-slip faults represent an age of structure with few documented examples in the eastern Basin and Range.

  7. Does Karakorum Fault Cut Across the Great Himalaya? Findings of Strike Slip Active Fault Along the Humla-Karnali River in the Northwestern Part of Nepal

    NASA Astrophysics Data System (ADS)

    Kumahara, Y.; Maemoku, H.; Yagi, H.; Nagatomo, T.; Upreti, B. N.

    2005-12-01

    It is well known that collision between the Indian and the Eurasian plates does not cause only mega thrusting along the Himalayan front but also great strike-slip shear or N-S extensional zones in the Tibetan block. Active tectonics of Tibet is presumed to be extrusion of Tibetan block along great strike-slip faults such as the Altyn Tagh and the Kunlun faults and consequent evolution of normal faults of N-S direction in the tensional stress field. The Karakorum fault seems to be terminated by Himalayan range on its southeastern edge (Searle,1996). As a southeastern extension of the fault, we found a new fault named Yari fault that was strike-slip fault across the Great Himalayan Range along Humla-Karnali River using a method of photo interpretation of aerial photographs and US spy satellite images. Nakata (1989) showed that MCT (Main Central Trust) active fault system and Bari Gad fault which is located within the Lesser Himalaya of western Nepal are right-stepping echelon striking NW- SE for 170km based on photo interpretation and fieldwork, and also pointed out that those could connect to the Karakoram fault system. There was, however, a gap for about 100 km between the Karakoram fault and the northernmost of the MCT active fault system. In 1990_fs, the Topological Survey of Nepal took vertical air photographs covered all the territory with the aim of publishing topographical maps. With using those new aerial photographs, we recognized an active fault cutting the Great Himalaya in the northwestern Nepal up to the international border of China as NW extension of the MCT active fault system. It is named Yari fault after nearest village name, which has single trace for 50km striking NW-SE generally. In the east of Yari village, alluvial fans and river terraces of different age have been displaced along the fault trace continuously with marked by north-facing scarp and right-lateral offset stream. Yari fault should play very important role as a bridge connecting Karakorum fault on the north of Himalaya and MCT (Main Central Trust) active fault system that is located along the topographical boundary of Higher Himalaya and Lower Himalaya. We would like to establish a hypothesis that not only Tibetan block but also Himalayan ranges are being divided by a series of strike-slip faults such as those strike-slip faults and extruded eastward.

  8. Structural deformation and evolution of right-lateral strike-slip tectonics of the Liaohe western depression during the early Cenozoic

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Jia, Dong; Chen, Wei; Zhang, Yikun; Wang, Maomao; Li, Yiquan; Li, Haibin; Li, Shiqin; Zhou, Xiaojun; Wu, Long; Zhang, Meng; Shen, Li; Sun, Chuang; Jin, Ke

    2013-11-01

    The Tan-Lu fault zone (TLFZ) traverses the Liaohe western depression (LHWD), affords an exceptional opportunity to reveal the structural deformation and evolution of a major strike-slip fault of the LHWD using three dimensional seismic data and well data. In this paper, based on structural interpretations of the 3-D seismic data of the LHWD, combined with depth slice and seismic coherency, a variety of structural features in relation to right-lateral strike-slip fault (the western branch of the Tan-Lu fault) have been revealed presence in the depression, such as thrust faults (Xinlongtai, Taian-Dawa, and Chenjia faults), structural wedges, positive flower structures, and en echelon normal faults. Fault cutoffs, growth strata and the Neogene unconformity developed in the LHWD verify that the activity of right-lateral strike-slip from the late Eocene to Neogene (ca. 43-23 Ma). The study indicates that the right-lateral strike-slip played an important role in controlling the structural deformation and evolution of the LHWD in the early Cenozoic. Moreover, the front structural wedge generated the gross morphology of the Xinlongtai anticline and developed the Lengdong faulted anticline during the late Eocene, and the back structural wedge refolded the Lengdong faulted anticline zone in the late Eocene to the early Oligocene. Wrench-related structures (the Chenjia thrust fault and the en echelon normal faults) were developed during the late Oligocene. Uniform subsidence in the Neogene to Quaternary. Furthermore, the driving force of the right-lateral strike-slip deformation was originated from N-S extension stress related to the opening of the Japan Sea and NE-SW compression, as the far-field effect of India-Eurasia convergence.

  9. End points and trial design in geriatric oncology research: a joint European organisation for research and treatment of cancer--Alliance for Clinical Trials in Oncology--International Society Of Geriatric Oncology position article.

    PubMed

    Wildiers, Hans; Mauer, Murielle; Pallis, Athanasios; Hurria, Arti; Mohile, Supriya G; Luciani, Andrea; Curigliano, Giuseppe; Extermann, Martine; Lichtman, Stuart M; Ballman, Karla; Cohen, Harvey Jay; Muss, Hyman; Wedding, Ulrich

    2013-10-10

    Selecting the most appropriate end points for clinical trials is important to assess the value of new treatment strategies. Well-established end points for clinical research exist in oncology but may not be as relevant to the older cancer population because of competing risks of death and potentially increased impact of therapy on global functioning and quality of life. This article discusses specific clinical end points and their advantages and disadvantages for older individuals. Randomized or single-arm phase II trials can provide insight into the range of efficacy and toxicity in older populations but ideally need to be confirmed in phase III trials, which are unfortunately often hindered by the severe heterogeneity of the older cancer population, difficulties with selection bias depending on inclusion criteria, physician perception, and barriers in willingness to participate. All clinical trials in oncology should be without an upper age limit to allow entry of eligible older adults. In settings where so-called standard therapy is not feasible, specific trials for older patients with cancer might be required, integrating meaningful measures of outcome. Not all questions can be answered in randomized clinical trials, and large observational cohort studies or registries within the community setting should be established (preferably in parallel to randomized trials) so that treatment patterns across different settings can be compared with impact on outcome. Obligatory integration of a comparable form of geriatric assessment is recommended in future studies, and regulatory organizations such as the European Medicines Agency and US Food and Drug Administration should require adequate collection of data on efficacy and toxicity of new drugs in fit and frail elderly subpopulations. PMID:24019549

  10. Positive Proof.

    ERIC Educational Resources Information Center

    Auty, Geoffrey

    1988-01-01

    Presents experiments which show that in electrostatics there are logical reasons for describing charged materials as positive or negative. Indicates that static and current electricity are not separate areas of physics. Diagrams of experiments and circuits are included. (RT)

  11. Nursing Positions

    MedlinePLUS

    ... and actually needs to feed. Getting Comfortable With Breastfeeding Nursing can be one of the most challenging ... a mother. As you become more used to breastfeeding your baby, you can try different positions or ...

  12. The Hills are Alive: Dynamic Ridges and Valleys in a Strike-Slip Environment

    NASA Astrophysics Data System (ADS)

    Duvall, A. R.; Tucker, G. E.

    2014-12-01

    Strike-slip fault zones have long been known for characteristic landforms such as offset and deflected rivers, linear strike-parallel valleys, and shutter ridges. Despite their common presence, questions remain about the mechanics of how these landforms arise or how their form varies as a function of slip rate, geomorphic process, or material properties. We know even less about what happens far from the fault, in drainage basin headwaters, as a result of strike-slip motion. Here we explore the effects of horizontal fault slip rate, bedrock erodibility, and hillslope diffusivity on river catchments that drain across an active strike-slip fault using the CHILD landscape evolution model. Model calculations demonstrate that lateral fault motion induces a permanent state of landscape disequilibrium brought about by fault offset-generated river lengthening alternating with abrupt shortening due to stream capture. This cycle of shifting drainage patterns and base level change continues until fault motion ceases thus creating a perpetual state of transience unique to strike-slip systems. Our models also make the surprising prediction that, in some cases, hillslope ridges oriented perpendicular to the fault migrate laterally in conjunction with fault motion. Ridge migration happens when slip rate is slow enough and/or diffusion and river incision are fast enough that the hillslopes can respond to the disequilibrium brought about by strike-slip motion. In models with faster slip rates, stronger rocks or less-diffusive hillslopes, ridge mobility is limited or arrested despite the fact that the process of river lengthening and capture continues. Fast-slip cases also develop prominent steep fault-facing hillslope facets proximal to the fault valley and along-strike topographic profiles with reduced local relief between ridges and valleys. Our results demonstrate the dynamic nature of strike-slip landscapes that vary systematically with a ratio of bedrock erodibility (K) and hillslope diffusivity (D) to the rate of horizontal advection of topography (v). These results also reveal a potential set of recognizable geomorphic signatures within strike-slip systems that should be looked to as indicators of fault activity and/or material properties.

  13. Effect of vertically extended strike object on the distribution of current along the lightning channel

    NASA Astrophysics Data System (ADS)

    Rachidi, F.; Rakov, V. A.; Nucci, C. A.; Bermudez, J. L.

    2002-12-01

    On the basis of a distributed-source representation of the lightning channel, the mathematical formulations of the so-called engineering lightning return stroke models are generalized to take into account the presence of a vertically extended strike object. The strike object is modeled as a lossless uniform transmission line, and the reflection coefficients are all assumed to be constant. The distribution of current along the lightning channel for each model is expressed in terms of the "undisturbed" current, object height, and current reflection coefficients at the top and the bottom of the object. The undisturbed current is defined as the current that would flow in the channel if the current reflection coefficients at the extremities of the strike object were equal to zero, that is, the characteristic impedances of the lightning channel and the strike object were equal to each other and equal to the grounding impedance of the strike object. The distributed-source representation of the lightning channel adopted in this study allows for a more general and straightforward formulations of the generalized return-stroke models than the traditional representations implying a lumped current source at the bottom of the channel, including a self-consistent treatment of the impedance discontinuity at the tower top.

  14. Repeated Strike Process During Disconnector Operation in Ultra-High Voltage Gas-Insulated Switchgear

    NASA Astrophysics Data System (ADS)

    Guan, Yonggang; Cai, Yuanji; Chen, Weijiang; Liu, Weidong; Li, Zhibing; Yue, Gongchang; Zhang, Junmin

    2016-03-01

    Very fast transient over-voltage (VFTO), induced by disconnector operations in gas-insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the experimental results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO. supported in part by National Natural Science Foundation of China (No. 51277106) and in part by the National Basic Research Program of China (973 Program) (No. 2011CB209405)

  15. Optical diagnostics and numerical modelling of arc re-strikes in low-voltage circuit breakers

    NASA Astrophysics Data System (ADS)

    Fivet, C.; Barrault, M.; Petit, P.; Chvrier, P.; Fleurier, C.; Andr, V.

    1997-11-01

    This paper is devoted to the study of the phenomenon of arc re-striking in low-voltage circuit breakers. The arc re-strike can be described as a sudden re-appearance in the arcing contact region when the arc had been situated in the quenching chamber a few tens of microseconds before. Our experimental investigations have established that the critical arcing contact region is still crossed by a so-called residual current of the order of several amperes. A gas temperature of around 4000 K was derived both from fine electrical measurements and from a molecular spectroscopy technique just before the occurrence of the arc re-strike. We also demonstrate that the re-strike takes place through the growth of the remaining current of several amperes in the arcing contact region. A numerical approach was carried out with a two-dimensional hydrodynamic code. This was found able to describe the arc movement in the model circuit breaker throughout a high-current-interruption operation and, notably, to simulate the arc re-strikes. The simulation exhibits the role of the flow of gas evaporated from the wall in the process of maintaining a slightly conductive medium in the arc ignition region.

  16. Prevention of blowfly strike on lambs with the insect growth regulator dicyclanil.

    PubMed

    Lonsdale, B; Schmid, H R; Junquera, P

    2000-11-01

    In three multicentered field trials run during 1995 to 1997, involving a total of 12,928 lambs, the preventive effects on blowfly strike of a ready-to-use 5 per cent dicyclanil pour-on formulation and of a ready-to-use 6 per cent cyromazine pour-on formulation were compared with untreated controls for periods of up to 22 weeks. Their efficacy was assessed by calculating the consolidated cumulative strike rate for each treatment group and the consolidated percentage reduction of flystrike achieved by the two formulations. The consolidated cumulative strike rate for all three years together reached 29.2 per cent for the untreated control lambs at week 22, 2.8 per cent for the dicyclanil-treated lambs at week 22, and 6.9 per cent for the cyromazine-treated lambs at week 20. The consolidated cumulative percentage reduction of blowfly strike remained above 89 per cent for the dicyclanil-treated lambs. For the cyromazine-treated lambs the consolidated cumulative percentage reduction of blowfly strike reached 90 per cent during weeks 9 to 10, and 80 per cent during weeks 11 to 12. PMID:11095393

  17. Estimate of the probability of a lightning strike to the Galileo probe

    NASA Astrophysics Data System (ADS)

    Borucki, W. J.

    1985-04-01

    Lightning strikes to aerospace vehicles occur mainly in or near clouds. As the Galileo entry probe will pass most of its operational life in the clouds of Jupiter, which is known to have lightning activity, the present study is concerned with the risk of a lightning strike to the probe. A strike to the probe could cause physical damage to the structure and/or damage to the electronic equipment aboard the probe. It is thought to be possible, for instance, that the instrument failures which occurred on all four Pioneer Venus entry probes at an altitude of 12 km were due to an external electric discharge. The probability of a lightning strike to the Galileo probe is evaluated. It is found that the estimate of a strike to the probe is only 0.001, which is about the same as the expected failure rate due to other design factors. In the case of entry probes to cloud-covered planets, a consideration of measures for protecting the vehicle and its payload from lightning appears to be appropriate.

  18. Do warning displays predict striking behavior in a viperid snake, the cottonmouth (Agkistrodon piscivorus)?

    SciTech Connect

    Glaudas, X. and C.T. Winne

    2007-01-01

    Warning displays are defined as signals designed to intimidate predators or indicate a proclivity to fight. However, support for the idea that warning behaviors signal an intent to fight is largely based on anecdotes and isolated observations, and a complete understanding of antipredator behavior will only be achieved if specific hypotheses are experimentally tested. Herein, we tested in a North American viperid snake, the cottonmouth (Agkistrodon piscivorus), the hypothesis that warning displays serve as a reliable signal to potential predators that a snake will strike. The cottonmouth exhibits two stereotypical warning displays during predator confrontation, i.e., mouth gaping and tail vibrations, making it an ideal study organism to experimentally test the relationship between warning displays and defensive striking. To test this idea, we recorded the sequence of defensive behavior--gaping, tail vibrating, and striking--of cottonmouths towards a standardized predatory stimulus in the laboratory. As predicted, snakes that gaped during the trials were subsequently more likely to strike than snakes that did not. In contrast, striking behavior was independent of the occurrence of tail vibrations. Our results suggest that gaping behavior--but not tail-vibrating behavior--may provide an honest signal to would-be predators.

  19. A classification of surface ruptures of strike-slip faults: comparison with analog models

    NASA Astrophysics Data System (ADS)

    Hsieh, S.; Neubauer, F.

    2012-12-01

    A fault is a planar fracture or discontinuity in surface or narrow zone with visible shear displacement along the zone. In detail, strike-slip faults are complex anastomosing structures consisting of a number of structural elements and growing from small fractures to map-scale structure by accumulating displacement from single and multiple earthquakes. We studied the surface expression of well documented high-magnitude earthquakes on four major faults (San Andreas, Altyn, Kunlun and Darfield faults). The expression of strike-slip faults on the Earth's surface by earthquake can be simply classified into five groups: lineament and/or fracture, tectonic scarp, tectonic depression, tectonic bulge and laterally offset landforms. Each type of anomalous landforms can provide evidence for place, activity and property of the fault structures. To classify the surface ruptures of strike-slip fault we adopt results of basement strike-slip faulting experiments (e.g., Mandl 2000; Leever et al., 2011) to understand the overall fault architecture, also by measurement of geomorphic expression can understand the geometry of the fault on subsurface. The size and arrangement of individual structural elements on surface allow a rough estimate of the structure at depth and distinction between transpressional, pure strike-slip and transtensional seetings.

  20. Neotectonics of a subduction/strike-slip transition: the northeastern Dominican Republic

    SciTech Connect

    Winslow, M.A.; McCann, W.R.

    1985-01-01

    The Septentrional fault system in the northeastern Dominican Republic marks the zone where the North American-Carribean plate boundary is evolving from subduction to strike-slip motion, and where terranes appear to be forming and migrating laterally in a subduction complex/forearc region. On the Island of Hispaniola, slip vectors are oblique to the strike of the Puerto Rico trench, and oblique subduction thrusts the upper plate over normal seafloor. The offshore geology and seismicity of the northern Caribbean suggest that uplift, broad crustal warping, thrusting, and strike-slip faulting (ie. collisional tectonics) should be present in the northern part of the Dominican Republic. The high topography (>1000m), high levels of seismicity, and large earthquakes support the hypothesis of contemporary deformation in Hispaniola. In this region, the subduction regime dies out toward the west, and deformation is transferred to onshore, oblique-slip faults. As this change in tectonic style has occurred in Neogene to Recent times, we are investigating the modern evolution of a plate boundary. We have already documented: (1) the presence of a strike-slip faulting in the northeastern Dominican Republic; (2) an anomalous push-up structure; and (3) a region of numerous splay faults. In conclusion, recent seismicity suggest a wide zone of deformation and variations in interplate motions near Hispaniola. This island lies at the western limit of active underthrusting and at the eastern limit of onshore faulting, i.e., at an important transition from a subduction to strike-slip regime.

  1. Point Defects in Minerals

    NASA Astrophysics Data System (ADS)

    Schock, Robert N.

    1985-05-01

    Point defects exist in all crystals at temperatures above absolute zero. They arise either to prevent charge imbalances d u e to the presence of impurities or because thermal energy has caused atoms to be displaced from their normal positions in th e structure. T h e atoms are free to migrate within the crystal, and this migration provides an energy-efficient mechanism for the movement and mixing of atoms. This movement results in mass transport, or diffusion, and in the attainment of thermal equilibrium. If the defect can be defined in terms of a site in a crystal lattice, it is called a point defect. More complex defects, such as dislocations, grain boundaries, or inclusions, can be considered as extensions of point defects in one or more dimensions. Point defects can be treated as chemical entities, and their behavior can be quantitatively predicted by various theories. Their role in minerals can thus be predicted, although the minerals of most interest, the silicates, are chemically and structurally complex enough to render the work tedious. Nevertheless, many techniques developed in other fields are now being applied to understanding the behavior of point defects in minerals that are important to the evolution of the earth and the terrestrial planets.

  2. Probability, consequences, and mitigation for lightning strikes to Hanford site high-level waste tanks

    SciTech Connect

    Zach, J.J.

    1996-08-01

    The purpose of this report is to summarize selected lightning issues concerning the Hanford Waste Tanks. These issues include the probability of lightning discharge striking the area immediately adjacent to a tank including a riser, the consequences of significant energy deposition from a lightning strike in a tank, and mitigating actions that have been or are being taken. The major conclusion of this report is that the probability of a lightning strike depositing sufficient energy in a tank to cause an effect on employees or the public is unlikely;but there are insufficient, quantitative data on the tanks and waste to prove that. Protection, such as grounding of risers and air terminals on existing light poles, is recommended.

  3. Probability, consequences, and mitigation for lightning strikes of Hanford high level waste tanks

    SciTech Connect

    Zach, J.J.

    1996-06-05

    The purpose of this report is to summarize selected lightning issues concerning the Hanford Waste Tanks. These issues include the probability of a lightning discharge striking the area immediately adjacent to a tank including a riser, the consequences of significant energy deposition from a lightning strike in a tank, and mitigating actions that have been or are being taken. The major conclusion of this report is that the probability of a lightning strike deposition sufficient energy in a tank to cause an effect on employees or the public is unlikely;but there are insufficient, quantitative data on the tanks and waste to prove that. Protection, such as grounding of risers and air terminals on existing light poles, is recommended.

  4. Strike-slip faulting in the West Siberian Platform: Insights from 3D seismic imagery

    NASA Astrophysics Data System (ADS)

    Gogonenkov, Georgiy N.; Timurziev, Akhmet I.

    2012-03-01

    The 3D seismic exploration, actively deployed in recent years on much of the West Siberian Platform - one of the world's largest oil and gas bearing basins - has brought out extensive development of a system of strike-slip faults within the basement. The fault system causes local structural and fluid flow anomalies within the Jurassic-Cretaceous sedimentary section, which is known to accommodate a multitude of large oil and gas deposits. This article will show the distribution geography and the scale of the basement strike-slip tectonics, and explain why this phenomenon, so clearly highlighted by 3D seismic, was not discovered earlier. The article will also consider how strike-slip faults are detected in the sedimentary cover and how they impact the characteristics of oil and gas fields located in their vicinity.

  5. ST-segment elevation following lightning strike: case report and review of the literature.

    PubMed

    Akın, Alper; Bilici, Meki; Demir, Fikri; Gözü Pirinççioğlu, Ayfer; Yıldırım, Ahmet

    2015-01-01

    Lightning strikes may cause injury to the heart, ranging from slight electrocardiographic changes to fatal damage. As heart injury is the most important cause of mortality in these patients, cardiac monitoring is crucial. Even though various ECG changes have been reported, published data on pathologic ST-segment changes is scarce. Herein, we present a seven-yearold patient with ST-segment elevation following a lightning strike. There is not sufficient data regarding lightning-related myocardial ischemia. However, because of the similar effects of lightning strikes and high-voltage electric shocks, we believe myocardial injury related to lightning may be managed in the same manner as is cardiac involvement associated with electric shock. PMID:26690603

  6. The Case for Using Blunt-Tipped Lightning Rods as Strike Receptors.

    NASA Astrophysics Data System (ADS)

    Moore, C. B.; Aulich, G. D.; Rison, William

    2003-07-01

    Conventional lightning rods used in the United States have sharp tips, a practice derived from Benjamin Franklin's discovery of a means to obtain protection from lightning. However, the virtue of sharp tips for strike reception has never been established. An examination of the relevant physics shows that very strong electric fields are required above the tips of rods in order that they function as strike receptors but that the gradients of the field strength over sharp-tipped rods are so great that, at distances of a few millimeters, the local fields are often too weak for the development of upward-going streamers. In field tests, rods with rounded tips have been found to be better strike receptors than were nearby sharp-tipped rods.

  7. Characteristics of lightning strikes experienced by the NASA F-1068 airplane

    NASA Technical Reports Server (NTRS)

    Fisher, B. D.; Mazur, V.; Plumer, J. A.; Gerlach, J. C.

    1984-01-01

    Thunderstorm penetrations were made during the 1980-1983 thunderstorm seasons by a NASA F-106B instrumented research aircraft in order to record lightning strike data and associated flight conditions. In 1980 and 1981, 10 direct lightning hits were received each year, with most penetrations occurring near the freezing level. In 1982 and 1983, a ground-based UHF-band radar was used to guide this aircraft through the upper, electrically active regions of thunderstorms (at altitudes above 6 km, corresponding to temperatures of less than -20 C), and 370 direct hits were recorded. The results of analyses of the radar, photographic, and surface inspection data are presented. The highest risk of lightning strike in the upper portions of a thundercloud occurred in regions where the ambient temperature was -40 to -50 C. Lightning strikes appear to be triggered by the aircraft.

  8. The recognition of strike-slip fault systems using imagery, gravity, and topographic data sets

    SciTech Connect

    Campagna, D.J.; Levandowski, D.W. Purdue University, West Lafayette, IN )

    1991-09-01

    The structural characteristics of two major strike-slip systems in the vicinity of Las Vegas, the left-lateral Lake Mead Fault System and the right-lateral Las-Vegas Valley Shear Zone, have been documented using Landsat imagery, topographic data, and gravity data. The strike-slip systems are found to display discrete, discontinuous fault segments the interaction of which generates regional and local deformation consistent with the kinematics of strike-slip faulting. The Echo Hills are a push-up feature located within a right step-over of a left-lateral fault. The Overton Arm is a deep pull-apart basin formed at an extensional stepover. Three distinct basins identified by the regional gravity anomaly data are aligned in a right-stepping pattern and are interpreted to have been formed by discontinuous right-stepping segments of the Las Vegas Valley Shear Zone. 23 refs.

  9. The recognition of strike-slip fault systems using imagery, gravity, and topographic data sets

    NASA Astrophysics Data System (ADS)

    Campagna, David J.; Levandowski, Donald W.

    1991-09-01

    The structural characteristics of two major strike-slip systems in the vicinity of Las Vegas, the left-lateral Lake Mead Fault System and the right-lateral Las-Vegas Valley Shear Zone, have been documented using Landsat imagery, topographic data, and gravity data. The strike-slip systems are found to display discrete, discontinuous fault segments the interaction of which generates regional and local deformation consistent with the kinematics of strike-slip faulting. The Echo Hills are a push-up feature located within a right step-over of a left-lateral fault. The Overton Arm is a deep pull-apart basin formed at an extensional stepover. Three distinct basins identified by the regional gravity anomaly data are aligned in a right-stepping pattern and are interpreted to have been formed by discontinuous right-stepping segments of the Las Vegas Valley Shear Zone.

  10. Electromagnetic images of a strike-slip fault: The Tintina fault-Northern Canadian

    NASA Astrophysics Data System (ADS)

    Ledo, Juanjo; Jones, Alan G.; Ferguson, Ian J.

    2002-04-01

    Wideband magnetotelluric (MT) data were acquired along three profiles crossing the strike-slip Tintina Fault in northwestern Canada. The MT responses obtained exhibit remarkable similarity from all three profiles, implying similar two-dimensional (2-D) electromagnetic behavior of the fault zone over a strike length of at least 350 km. Analyses of the MT responses for dimensionality corroborate the validity of assuming regional 2-D structures in interpretation. Several high conductivity anomalies at different depth scales are present in the models obtained, and we suggest that both the shallow structures and the deep crustal scale anomalies are caused by electronic conduction mechanisms in interconnected mineralized zones. Intriguingly, the middle and lower crust beneath the surface expression of the Tintina Fault is highly resistive, in contrast to some other large-scale strike-slip faults. This implies that fault zone processes that result in interconnected conducting phases are not generic in nature but are controlled by local conditions.

  11. Development of a simulated bird-strike test method. [Of aircraft turbine engine fan blade materials

    SciTech Connect

    Colvin, G.N.; Falls, J.R. )

    1990-05-01

    An inexpensive test method has been developed to predict the dynamic impact-response (bird-strike resistance) of aircraft turbine engine fan blade materials. The test utilizes an instrumented pendulum to transfer energy to a machined fan blade cross section. To validate the test, the relative performance of one wrought and four cast Ti-6Al-4V materials subjected to the simulated bird-strike test was compared to that of the same materials tested at Wright-Patterson Air Force Base by conventional bird-strike testing. The relative ranking of crack initiation loads determined from the simulated test corresponded to fan blade failure velocities determined by the Air Force test, thereby validating the simulated method as a screening tool for fan blade material development. 6 refs.

  12. Evaluation of blade-strike models for estimating the biological performance of large Kaplan hydro turbines

    SciTech Connect

    Deng, Z.; Carlson, T. J.; Ploskey, G. R.; Richmond, M. C.

    2005-11-01

    Bio-indexing of hydro turbines has been identified as an important means to optimize passage conditions for fish by identifying operations for existing and new design turbines that minimize the probability of injury. Cost-effective implementation of bio-indexing requires the use of tools such as numerical and physical turbine models to generate hypotheses for turbine operations that can be tested at prototype scales using live fish. Blade strike has been proposed as an index variable for the biological performance of turbines. Report reviews an evaluation of the use of numerical blade-strike models as a means with which to predict the probability of blade strike and injury of juvenile salmon smolt passing through large Kaplan turbines on the mainstem Columbia River.

  13. Effect of lightning strike on bromine intercalated graphite fiber/epoxy composites

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Slabe, Melissa E.; Brink, Norman O.

    1991-01-01

    Laminar composites were fabricated from pristine and bromine intercalated pitch based graphite fibers. It was found that laminar composites could be fabricated using either pristine or intercalated graphite fibers using standard fabrication techniques. The intercalated graphite fiber composites had electrical properties which were markedly improved over both the corresponding pitch based and polyacrylonitrile (PAN) based composites. Despite composites resistivities more than an order of magnitude lower for pitch based fiber composites, the lightning strike resistance was poorer than that of the Pan based fiber composites. This leads to the conclusion that the mechanical properties of the pitch fibers are more important than electrical or thermal properties in determining the lightning strike resistance. Based on indicated lightning strike tolerance for high elongation to failure materials, the use of vapor grown, rather than pitch based graphite fibers appears promising.

  14. Strike-slip faults in the Moroccan Rif: Their geophysical signatures and hydrocarbon potential

    SciTech Connect

    Jobidon, G.P.; Dakki, M.

    1994-12-31

    The Rif Domain in Northern Morocco includes major movements along left-lateral strike-slips faults that created various structures and influenced depositional systems. The major ones are the Jebha fault in the Rif`s northwest area, and the Nekkor fault that extends southwesterly from the Mediterranean sea toward the Meseta. Although identified by surface geology in the east, the western extent of the faults is ambiguous. Detail interpretation of gravity and magnetic maps provide a better definition of their locations and related structures. The Rif`s geology is a mirror image of the right-lateral strike-slip fault system of Venezuela and Trinidad. Most features associated with the Rif`s strike-slip faults have not been explored to data and hydrocarbon potential remains a good possibility.

  15. Position indicator

    DOEpatents

    Tanner, David E. (Poway, CA)

    1981-01-01

    A nuclear reactor system is described in which a position indicator is provided for detecting and indicating the position of a movable element inside a pressure vessel. The movable element may be a valve element or similar device which moves about an axis. Light from a light source is transmitted from a source outside the pressure vessel to a first region inside the pressure vessel in alignment with the axis of the movable element. The light is redirected by a reflector prism to a second region displaced radially from the first region. The reflector prism moves in response to movement of the movable element about its axis such that the second region moves arcuately with respect to the first region. Sensors are arrayed in an arc corresponding to the arc of movement of the second region and signals are transmitted from the sensors to the exterior of the reactor vessel to provide indication of the position of the movable element.

  16. Strike-slip faults on Mars: Observations and implications for global tectonics and geodynamics

    NASA Astrophysics Data System (ADS)

    Andrews-Hanna, Jeffrey C.; Zuber, Maria T.; Hauck, Steven A.

    2008-08-01

    The tectonic evolution of Mars has been driven primarily by the interaction of Tharsis-induced loading stresses with a uniform contractional stress field, leading to global assemblages of graben and wrinkle ridges. Until recently, strike-slip faults have appeared to be largely absent from the tectonic record. We here present evidence for a new set of Noachian to Early Hesperian strike-slip faults southwest of Tharsis. The best-preserved fault in the newly mapped set has a length of ~200 km and measured lateral offset of 5-9 km. We use the locations of both previously mapped and newly identified strike-slip faults to investigate the tectonic and geodynamic evolution of Mars. We model the tectonic evolution of the planet in response to the evolving balance between the loading and contractional stresses, finding widespread regions in which strike-slip faulting was favored. The observed tectonic history is consistent with a scenario in which loading-induced stresses peaked early in Mars history, followed by the growth of contractional stresses, leading to a shift in the preferred locus of strike-slip faulting from regions southwest of Tharsis in the Noachian to Early Hesperian, to northwest of Tharsis in the Early Amazonian. The contractional strain history inferred from the ages and locations of the strike-slip faults is consistent with the strains calculated from models of the thermal evolution of Mars in which the gradual secular cooling of the planet over time was augmented by plume-induced contraction during Tharsis formation in the Noachian.

  17. FD-TD numerical simulation of an entire lightning strike on the C160 aircraft

    NASA Technical Reports Server (NTRS)

    Alliot, J. C.; Grando, J.; Muller, J. D.; Ferrieres, X.

    1991-01-01

    Experimental transient electromagnetic field measurements were performed on a Transall C160 aircraft during in-flight lightning strikes. The data allow a test of the predictive capabilities of a three dimensional time domain finite difference code (ALICE) developed at ONERA in order to investigate lightning-aircraft interactions. Using a transfer function technique in the 3D code, it is shown that a bi-leader attached to an aircraft can be simulated by a linear model, and so the electromagnetic fields can be calculated anywhere on the vehicle. Comparison of experimental and numerical results were made for several lightning strikes. Skin current density and electromagnetic field distributions are discussed in detail.

  18. Junior Doctors in England Strike for the First Time in 40 Years.

    PubMed

    McKay, Ailsa J; Majeed, Azeem

    2016-01-01

    The UK government recently stated its intention to impose a new junior doctor contract in England. Related negotiations between the British Medical Association and government representatives started in 2013. These have to-date failed to reassure doctors, who are concerned about risks to their welfare, patient safety, and the future of England's National Health Service. With the impending imposition of the new contract, and lack of progress, junior doctors felt the risks of striking had fallen below those of inaction. Hence, the first strike staged by the English medical workforce for 40 years occurred in January 2016. PMID:26945306

  19. MoMAR observatory: A Geophysical, Geological and Oceanographical Approach to the Monitoring of the Lucky Strike Segment (GRAVILUCK Cruise)

    NASA Astrophysics Data System (ADS)

    Ballu, V.; Cannat, M.; Graviluck Scientific Party, A.

    2006-12-01

    The GRAVILUCK expedition, conducted in August 2006 on the R/V ATALANTE, was mainly dedicated to the installation of a seafloor geodetic network in the framework of the MoMAR ("Monitoring the Mid-Atlantic Ridge") project, to study active mid-ocean ridge processes along a slow-spreading ridge segment. The chosen site for this integrated "observatory" effort is the Lucky Strike segment (37°N) along the Mid-Atlantic Ridge, South of the Azores Archipelago; it combines both logistic and scientific interests, and has been studied in depth by geologists, geophysicists and biologists for many years. It also presents an intense hydrothermal activity and hosts an axial magma chamber under its center discovered last year during the SISMOMAR cruise. The installation of 9 permanent geodetic benchmarks and the time-zero pressure and gravity measurements were conducting during 19 Nautile dives. Pressure changes measured at a benchmark can be due to environmental variability, to a change in the elevation of the point, or to both. To quantify environmental variations, we monitored water column with full depth CTD prior to each dive, and shallow CTD yoyos down to 500 m during the dives. These oceanographic measurements will allow us to directly model and remove part of the environmental variability and thus increase our capability to detect small vertical motions over several years. Three additional Nautile dives were dedicated to geology and gravity cartography of the central volcano. In addition to the day program, 10 nights were devoted to a geological survey using the TowCam (camera, magnetometer, wax coring, CTD) to characterize tectonic and magmatic features of the Lucky Strike volcano, their relationship to the magma chamber location, and identification of areas of most recent apparent volcanic activity; 10 other nights were dedicated to studying ocean circulation and induced mixing around the Lucky Strike site. GRAVILUCK cruise Scientific Party: CNRS/IPGP: J. Ammann, V. Ballu, M. Cannat, C. Deplus, J. Escartin, O. Pot, C. Rommevaux-Jestin; IPGP: C. Cadio, S. Deroussi, M. Kitazawa; CNRS/INSU: G. Duveau, C. Marec; Univ. Açores: I. Bashmachnikov; Harvard Univ.: A. Bezos; IGN: MN. Bouin; FSU: E. Howarth, L. St Laurent; CNRS/UBO: M. Maia; LOCEAN: P. Bouruet-Aubertot, A. Lourenço, G. Reverdin; SIO: G. Sasagawa; WHOI: S. A. Soule; LDEO: A. Thurnherr.

  20. The San Andreas Fault and a Strike-slip Fault on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay.

    The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left).

    A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements.

    Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may be filled in mostly by sedimentary and erosional material deposited from above. Comparisons between faults on Europa and Earth may generate ideas useful in the study of terrestrial faulting.

    One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. The tidal tension opens the fault; subsequent tidal stress causes it to move lengthwise in one direction. Then the tidal forces close the fault up again. This prevents the area from moving back to its original position. If it moves forward with the next daily tidal cycle, the result is a steady accumulation of these lengthwise offset motions.

    Unlike Europa, here on Earth, large strike-slip faults such as the San Andreas are set in motion not by tidal pull, but by plate tectonic forces from the planet's mantle.

    North is to the top of the picture. The Earth picture (left) shows a LandSat Thematic Mapper image acquired in the infrared (1.55 to 1.75 micrometers) by LandSat5 on Friday, October 20th 1989 at 10:21 am. The original resolution was 28.5 meters per picture element.

    The Europa picture (right)is centered at 66 degrees south latitude and 195 degrees west longitude. The highest resolution frames, obtained at 40 meters per picture element with a spacecraft range of less than 4200 kilometers (2600 miles), are set in the context of lower resolution regional frames obtained at 200 meters per picture element and a range of 22,000 kilometers (13,600 miles). The images were taken on September 26, 1998 by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL HTTP://www.jpl.nasa.gov/galileo/sepo

  1. Efficacy of the polo-like kinase inhibitor rigosertib, alone or in combination with Abelson tyrosine kinase inhibitors, against break point cluster region-c-Abelson-positive leukemia cells

    PubMed Central

    Okabe, Seiichi; Tauchi, Tetsuzo; Tanaka, Yuko; Sakuta, Juri; Ohyashiki, Kazuma

    2015-01-01

    The potency of Abelson (ABL) tyrosine kinase inhibitors (TKIs) against chronic myeloid leukemia (CML) has been demonstrated. However, ABL TKI resistance can develop. In this study, we investigated the efficacy of a combination therapy including rigosertib (ON 01910.Na), a polo-like kinase (PLK) and phosphoinositide 3-kinase (PI3K) inhibitor, and ABL TKIs. A 72-h rigosertib treatment was found to inhibit cell growth, induce apoptosis, reduce phosphorylation of the breakpoint cluster region-c (BCR)-ABL and its substrate Crk-L, and increase the activities of caspase 3 and poly (ADP-ribose) polymerase (PARP). This combination therapy also exerted a synergistic inhibitory effect on Philadelphia chromosome (Ph)-positive cell proliferation and reduced the phosphorylation of BCR-ABL and Crk-L while increasing that of cleaved PARP and the H2A.X histone. Rigosertib also potently inhibited the growth of ABL TKI-resistant cells, and cotreatment with ABL TKIs and rigosertib induced higher cytotoxicity. These results indicate that rigosertib treatment may be a powerful strategy against ABL TKI-resistant cells and could enhance the cytotoxic effects of ABL TKIs. PMID:26008977

  2. 29 CFR 901.5 - Agreement to refrain from strike or lockout.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Agreement to refrain from strike or lockout. 901.5 Section 901.5 Labor Regulations Relating to Labor (Continued) CONSTRUCTION INDUSTRY COLLECTIVE BARGAINING COMMISSION POLICY STATEMENT ON COLLECTIVE BARGAINING DISPUTES AND APPLICABLE PROCEDURES 901.5 Agreement...

  3. 29 CFR 901.5 - Agreement to refrain from strike or lockout.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Agreement to refrain from strike or lockout. 901.5 Section 901.5 Labor Regulations Relating to Labor (Continued) CONSTRUCTION INDUSTRY COLLECTIVE BARGAINING COMMISSION POLICY STATEMENT ON COLLECTIVE BARGAINING DISPUTES AND APPLICABLE PROCEDURES 901.5 Agreement...

  4. 29 CFR 901.5 - Agreement to refrain from strike or lockout.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Agreement to refrain from strike or lockout. 901.5 Section 901.5 Labor Regulations Relating to Labor (Continued) CONSTRUCTION INDUSTRY COLLECTIVE BARGAINING COMMISSION POLICY STATEMENT ON COLLECTIVE BARGAINING DISPUTES AND APPLICABLE PROCEDURES 901.5 Agreement...

  5. 29 CFR 901.5 - Agreement to refrain from strike or lockout.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Agreement to refrain from strike or lockout. 901.5 Section 901.5 Labor Regulations Relating to Labor (Continued) CONSTRUCTION INDUSTRY COLLECTIVE BARGAINING COMMISSION POLICY STATEMENT ON COLLECTIVE BARGAINING DISPUTES AND APPLICABLE PROCEDURES 901.5 Agreement...

  6. High tsunami frequency as a result of combined strike-slip faulting and coastal landslides

    USGS Publications Warehouse

    Hornbach, M.J.; Braudy, N.; Briggs, R.W.; Cormier, M.-H.; Davis, M.B.; Diebold, J.B.; Dieudonne, N.; Douilly, R.; Frohlich, C.; Gulick, S.P.S.; Johnson, H. E., III; Mann, P.; McHugh, C.; Ryan-Mishkin, K.; Prentice, C.S.; Seeber, L.; Sorlien, C.C.; Steckler, M.S.; Symithe, S.J.; Taylor, F.W.; Templeton, J.

    2010-01-01

    Earthquakes on strike-slip faults can produce devastating natural hazards. However, because they consist predominantly of lateral motion, these faults are rarely associated with significant uplift or tsunami generation. And although submarine slides can generate tsunami, only a few per cent of all tsunami are believed to be triggered in this way. The 12 January Mw 7.0 Haiti earthquake exhibited primarily strike-slip motion but nevertheless generated a tsunami. Here we present data from a comprehensive field survey that covered the onshore and offshore area around the epicentre to document that modest uplift together with slope failure caused tsunamigenesis. Submarine landslides caused the most severe tsunami locally. Our analysis suggests that slide-generated tsunami occur an order-of-magnitude more frequently along the Gonave microplate than global estimates predict. Uplift was generated because of the earthquake?s location, where the Caribbean and Gonave microplates collide obliquely. The earthquake also caused liquefaction at several river deltas that prograde rapidly and are prone to failure. We conclude that coastal strike-slip fault systems such as the Enriquillog-Plantain Garden fault produce relief conducive to rapid sedimentation, erosion and slope failure, so that even modest predominantly strike-slip earthquakes can cause potentially catastrophic slide-generated tsunamig-a risk that is underestimated at present. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  7. High tsunami frequency as a result of combined strike-slip faulting and coastal landslides

    USGS Publications Warehouse

    Hornbach, Matthew J.; Braudy, Nicole; Briggs, Richard W.; Cormier, Marie-Helene; Davis, Marcy B.; Diebold, John B.; Dieudonne, Nicole; Douilly, Roby; Frohlich, Cliff; Gulick, Sean P.S.; Johnson, Harold E., III; Mann, Paul; McHugh, Cecilia; Ryan-Mishkin, Katherine; Prentice, Carol S.; Seeber, Leonardo; Sorlien, Christopher C.; Steckler, Michael S.; Symithe, Steeve Julien; Taylor, Frederick W.; Templeton, John

    2010-01-01

    Earthquakes on strike-slip faults can produce devastating natural hazards. However, because they consist predominantly of lateral motion, these faults are rarely associated with significant uplift or tsunami generation. And although submarine slides can generate tsunami, only a few per cent of all tsunami are believed to be triggered in this way. The 12 January Mw 7.0 Haiti earthquake exhibited primarily strike-slip motion but nevertheless generated a tsunami. Here we present data from a comprehensive field survey that covered the onshore and offshore area around the epicentre to document that modest uplift together with slope failure caused tsunamigenesis. Submarine landslides caused the most severe tsunami locally. Our analysis suggests that slide-generated tsunami occur an order-of-magnitude more frequently along the Gonave microplate than global estimates predict. Uplift was generated because of the earthquake's location, where the Caribbean and Gonave microplates collide obliquely. The earthquake also caused liquefaction at several river deltas that prograde rapidly and are prone to failure. We conclude that coastal strike-slip fault systems such as the Enriquillo-Plantain Garden fault produce relief conducive to rapid sedimentation, erosion and slope failure, so that even modest predominantly strike-slip earthquakes can cause potentially catastrophic slide-generated tsunami - a risk that is underestimated at present.

  8. Does Three Strikes Really Deter? A Statistical Analysis of Its Impact on Crime Rates in California

    ERIC Educational Resources Information Center

    Kelly, John; Datta, Anusua

    2009-01-01

    This study uses California crime statistics for the years 1984-2004, to determine what effect, if any, the increased sentencing standards under the three-strikes legislation in California have had in deterring crime. This study follows a new approach in differentiating between the incapacitation effect and the deterrent effect of the law.

  9. A Hybrid Sport Education-Games for Understanding Striking/Fielding Unit for Upper Elementary Pupils

    ERIC Educational Resources Information Center

    Curtner-Smith, Matthew

    2004-01-01

    This article describes a hybrid Sport Education-Games for Understanding unit through which upper elementary pupils can learn to play basic striking/fielding games. The unit is written for a class of 30 pupils. The twenty-five lesson unit is described in detail within 10 stages: (1) Getting started and early skill, strategy, rule, and role work

  10. Why Teach a 100-Year-Old Strike?: The "Bread and Roses" Centenary

    ERIC Educational Resources Information Center

    Diamond, Norm

    2012-01-01

    Today's movement in support of the 99 percent is a reminder that throughout U.S. history, a major engine of change has been grass-roots organizing and solidarity. Major history textbooks, however, downplay the role of ordinary people in shaping events--especially those who formed labor unions and used the strike to assert their rights. One of the…

  11. 20 CFR 655.733 - What is the third LCA requirement, regarding strikes and lockouts?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is filed by the employer with DOL is covered by DHS regulations at 8 CFR 214.2(h)(17). For the... 8 CFR 214.2(h)(17) for effects of strikes or lockouts in general on the H-1B nonimmigrant's... employment. See 8 CFR 214.2(h)(17). (b) Documentation of the third labor condition statement. The...

  12. Models of Militancy: Support for Strikes and Work Actions among Public Employees.

    ERIC Educational Resources Information Center

    Schutt, Russell K.

    1982-01-01

    Examines support for militant action among the employees of a public assistance agency in which negotiations were occurring over a first contract. A questionnaire survey obtained information on whether employees were willing to strike over various issues during negotiations and whether they would participate in certain work actions, such as

  13. The Bellevue Teachers Strike and Its Implications for the Future of Postindustrial Reform Unionism

    ERIC Educational Resources Information Center

    Jacoby, Daniel F.; Nitta, Keith

    2012-01-01

    Striking for nine days in 2008, teachers in Bellevue carved a distinctive path through the contradictory movements for professional reform unionism and national accountability. In addition to compensation, Bellevue's teachers struck over the top-down prescriptive management epitomized by the Gates Foundation supported "Curriculum Web." Where

  14. Over-the-Line: An Alternative Striking/Fielding Game for Understanding

    ERIC Educational Resources Information Center

    Gorecki, Jennifer J.

    2004-01-01

    Over-the-Line is a striking/fielding game designed from the perspective of the Games for Understanding tactical model to serve as an alternative to traditional kickball, softball, and baseball. Over-the-Line can be modified for developmental appropriateness and tasks can increase in complexity as tactical awareness is attained. This article shares…

  15. A Hybrid Sport Education-Games for Understanding Striking/Fielding Unit for Upper Elementary Pupils

    ERIC Educational Resources Information Center

    Curtner-Smith, Matthew

    2004-01-01

    This article describes a hybrid Sport Education-Games for Understanding unit through which upper elementary pupils can learn to play basic striking/fielding games. The unit is written for a class of 30 pupils. The twenty-five lesson unit is described in detail within 10 stages: (1) Getting started and early skill, strategy, rule, and role work…

  16. 20 CFR 655.733 - What is the third LCA requirement, regarding strikes and lockouts?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... is filed by the employer with DOL is covered by DHS regulations at 8 CFR 214.2(h)(17). For the... 8 CFR 214.2(h)(17) for effects of strikes or lockouts in general on the H-1B nonimmigrant's... employment. See 8 CFR 214.2(h)(17). (b) Documentation of the third labor condition statement. The...

  17. 20 CFR 655.733 - What is the third LCA requirement, regarding strikes and lockouts?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is filed by the employer with DOL is covered by DHS regulations at 8 CFR 214.2(h)(17). For the... 8 CFR 214.2(h)(17) for effects of strikes or lockouts in general on the H-1B nonimmigrant's... employment. See 8 CFR 214.2(h)(17). (b) Documentation of the third labor condition statement. The...

  18. 20 CFR 655.733 - What is the third LCA requirement, regarding strikes and lockouts?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... is filed by the employer with DOL is covered by DHS regulations at 8 CFR 214.2(h)(17). For the... 8 CFR 214.2(h)(17) for effects of strikes or lockouts in general on the H-1B nonimmigrant's... employment. See 8 CFR 214.2(h)(17). (b) Documentation of the third labor condition statement. The...

  19. 20 CFR 655.733 - What is the third LCA requirement, regarding strikes and lockouts?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... is filed by the employer with DOL is covered by DHS regulations at 8 CFR 214.2(h)(17). For the... 8 CFR 214.2(h)(17) for effects of strikes or lockouts in general on the H-1B nonimmigrant's... employment. See 8 CFR 214.2(h)(17). (b) Documentation of the third labor condition statement. The...

  20. Strikes, Scabs, and Tread Separations: Labor Strife and the Production of Defective Bridgestone/firestone Tires.

    ERIC Educational Resources Information Center

    Krueger, Alan B.; Mas, Alexandre

    2004-01-01

    This paper provides a case study of the effect of labor relations on product quality. We consider whether a long, contentious strike and the hiring of replacement workers at Bridgestone/Firestone's Decatur, Illinois, plant in the mid-1990s contributed to the production of defective tires. Using several independent data sources and looking before

  1. Defining the effective impact mass of elbow and shoulder strikes in ice hockey.

    PubMed

    Rousseau, Philippe; Hoshizaki, Thomas B

    2015-03-01

    Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports. PMID:25895554

  2. Changes in Kicking Pattern: Effect of Experience, Speed, Accuracy, and Effective Striking Mass

    ERIC Educational Resources Information Center

    Southard, Dan L.

    2014-01-01

    Purpose: The purposes of this study were to: (a) examine the effect of experience and goal constraints (speed, accuracy) on kicking patterns; (b) determine if effective striking mass was independent of ankle velocity at impact; and (c) determine the accuracy of kicks relative to independent factors. Method: Twenty participants were recruited to…

  3. Alberta's 2002 Teacher Strike: The Political Economy of Labor Relations in Education

    ERIC Educational Resources Information Center

    Barnetson, Bob

    2010-01-01

    In 2002, approximately two thirds of school teachers in the Canadian province of Alberta went on strike. Drawing on media, government and union documents, this case study reveals some contours of the political economy of labor relations in education that are normally hidden from view. Among these features are that the state can react to worker…

  4. Shell Tectonics: A Mechanical Model for Strike-slip Displacement on Europa

    NASA Technical Reports Server (NTRS)

    Rhoden, Alyssa Rose; Wurman, Gilead; Huff, Eric M.; Manga, Michael; Hurford, Terry A.

    2012-01-01

    We introduce a new mechanical model for producing tidally-driven strike-slip displacement along preexisting faults on Europa, which we call shell tectonics. This model differs from previous models of strike-slip on icy satellites by incorporating a Coulomb failure criterion, approximating a viscoelastic rheology, determining the slip direction based on the gradient of the tidal shear stress rather than its sign, and quantitatively determining the net offset over many orbits. This model allows us to predict the direction of net displacement along faults and determine relative accumulation rate of displacement. To test the shell tectonics model, we generate global predictions of slip direction and compare them with the observed global pattern of strike-slip displacement on Europa in which left-lateral faults dominate far north of the equator, right-lateral faults dominate in the far south, and near-equatorial regions display a mixture of both types of faults. The shell tectonics model reproduces this global pattern. Incorporating a small obliquity into calculations of tidal stresses, which are used as inputs to the shell tectonics model, can also explain regional differences in strike-slip fault populations. We also discuss implications for fault azimuths, fault depth, and Europa's tectonic history.

  5. Strikes, Scabs, and Tread Separations: Labor Strife and the Production of Defective Bridgestone/firestone Tires.

    ERIC Educational Resources Information Center

    Krueger, Alan B.; Mas, Alexandre

    2004-01-01

    This paper provides a case study of the effect of labor relations on product quality. We consider whether a long, contentious strike and the hiring of replacement workers at Bridgestone/Firestone's Decatur, Illinois, plant in the mid-1990s contributed to the production of defective tires. Using several independent data sources and looking before…

  6. Changes in Kicking Pattern: Effect of Experience, Speed, Accuracy, and Effective Striking Mass

    ERIC Educational Resources Information Center

    Southard, Dan L.

    2014-01-01

    Purpose: The purposes of this study were to: (a) examine the effect of experience and goal constraints (speed, accuracy) on kicking patterns; (b) determine if effective striking mass was independent of ankle velocity at impact; and (c) determine the accuracy of kicks relative to independent factors. Method: Twenty participants were recruited to

  7. Comparison of basin types in active and ancient strike-slip zones

    SciTech Connect

    Mann, P.; Bradley, D.

    1984-04-01

    Hydrocarbon exploration in strike-slip zones requires awareness of several distinct basin types, traditionally defined on the basis of bounding fault geometry: pull-aparts (P), fault-wedge basins (W), fault-angle basins (A), fault-flank basins (F), and ramp valleys (R). We compare the characteristics and frequency of these basin types in an active (40 post-Eocene basins of the northern and southern Caribbean) and ancient (19 Late Devonian-Carboniferous basins of the northern Appalachians) strike-slip setting. Pull-apart basins, which lengthen and deepen at fault discontinuities with increased strike-slip offset, constitute the best studied and most numerous basin type. Other recognizable basin types are less numerous and often shorter lived than pull-aparts, and this may reflect: (1) their role as precursory structures prior to concentration of strike-slip displacement on a single fault; (2) their role as interference structures at random fault junctures; and (3) the unlikelihood of preservation because of thinner sedimentary fill. Several disrupted basins of complex or unknown origin (D) appear to have initiated as pull-aparts and subsequently to have been offset into halves or modified into compressional ramp valleys. Using observations from active basins, several geologic criteria for distinguishing compressional vs. extensional origin of reactivated ancient basins are discussed.

  8. The Danger of Selectively Changing the Rules in Youth Sport: The Case of the Strike Zone

    ERIC Educational Resources Information Center

    Torres, Cesar R.

    2010-01-01

    Albeit well-intentioned, the practice of selectively changing the strike zone to promote young players' welfare is critically flawed. After discussing the central purpose of competitive sport, the duty of officials, and the significance of impartiality in officiating, this article demonstrates that this practice presents numerous practical…

  9. 76 FR 44579 - Notice of Availability of Environmental Assessment for Strike Fighter Realignment at Naval Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-26

    ... Naval Air Station Lemoore, CA AGENCY: Department of the Navy, DoD. ACTION: Notice. SUMMARY: Pursuant to... realignment of strike fighter assets at Naval Air Station (NAS) Lemoore. Dates and Addresses: Written comments... Realignment EA Project Manager; Naval Facilities Engineering Command, Southwest; Attn: Code EV21.AK;...

  10. Lift Fan Nozzle for Joint Strike Fighter Tested in NASA Lewis' Powered Lift Rig

    NASA Technical Reports Server (NTRS)

    Lam, David W.

    1998-01-01

    Under a nonreimbursable space act agreement between the NASA Lewis Research Center and the Allison Advanced Development Company, Allison tested a lift fan nozzle in Lewis' Powered Lift Rig. This test was in support of the Joint Strike Fighter program (formerly the Joint Advanced Strike Technology) sponsored by the Department of Defense, which will develop and field an affordable, multirole, next-generation, strike fighter aircraft for the Navy, Air Force, Marine Corps, and foreign allies. Allison, along with Pratt & Whitney Company, is part of the Lockheed Martin Corporation team that is scheduled to build a concept demonstrator aircraft by fiscal year 2001. The test was initiated in April and successfully completed in mid-July of 1997. Allison supplied a one-third-scale model of the lift fan nozzle, and Lewis provided the facility and the necessary support team. Various configurations, including pitching vectored angles ranging from 15deg forward to 60deg backward, were tested over a range of nozzle pressure ratios. Nozzle flow rates, thrust, and static pressures were measured for each of the configurations. Results from the test met the design requirements for the Joint Strike Fighter program and were in agreement with Allison's internal computational fluid dynamics (CFD) analyses. Data obtained from this test will also be used in the full-scale design of the lift fan system.

  11. Care around birth, infant and mother health and maternal health investments - Evidence from a nurse strike.

    PubMed

    Kronborg, Hanne; Sievertsen, Hans Henrik; Wüst, Miriam

    2016-02-01

    Care around birth may impact child and mother health and parental health investments. We exploit the 2008 national strike among Danish nurses to identify the effects of care around birth on infant and mother health (proxied by health care usage) and maternal investments in the health of their newborns. We use administrative data from the population register on 39,810 Danish births in the years 2007-2010 and complementary survey and municipal administrative data on 8288 births in the years 2007-2009 in a differences-in-differences framework. We show that the strike reduced the number of mothers' prenatal midwife consultations, their length of hospital stay at birth, and the number of home visits by trained nurses after hospital discharge. We find that this reduction in care around birth increased the number of child and mother general practitioner (GP) contacts in the first month. As we do not find strong effects of strike exposure on infant and mother GP contacts in the longer run, this result suggests that parents substitute one type of care for another. While we lack power to identify the effects of care around birth on hospital readmissions and diagnoses, our results for maternal health investments indicate that strike-exposed mothers-especially those who lacked postnatal early home visits-are less likely to exclusively breastfeed their child at four months. Thus reduced care around birth may have persistent effects on treated children through its impact on parental investments. PMID:26771337

  12. Nurses, industrial action and ethics: considerations from the 2010 South African public-sector strike.

    PubMed

    van Rensburg, Andr J; van Rensburg, Dingie J

    2013-11-01

    Several important ethical dilemmas emerge when nurses join a public-sector strike. Such industrial action is commonplace in South Africa and was most notably illustrated by a national wage negotiation in 2010. Media coverage of the proceedings suggested unethical behaviour on the part of nurses, and further exploration is merited. Laws, policies and provisional codes are meant to guide nurses' behaviour during industrial action, while ethical theories can be used to further illuminate the role of nurses in industrial action. There are, however, important aspects to consider before judging whether nurses act unethically when striking. Following Loewy's suggestion that the nature of the work, the proceeding commitment of the nurse to the patient, the prevailing situation when the strike is planned and the person(s) who stand(s) to benefit from the strike be considered, coupled with a consideration of the South African historical socio-political context, important aspects of the ethics of nurses' behaviour in industrial action transpire. PMID:23454981

  13. The Bellevue Teachers Strike and Its Implications for the Future of Postindustrial Reform Unionism

    ERIC Educational Resources Information Center

    Jacoby, Daniel F.; Nitta, Keith

    2012-01-01

    Striking for nine days in 2008, teachers in Bellevue carved a distinctive path through the contradictory movements for professional reform unionism and national accountability. In addition to compensation, Bellevue's teachers struck over the top-down prescriptive management epitomized by the Gates Foundation supported "Curriculum Web." Where…

  14. 48 CFR 1252.222-70 - Strikes or picketing affecting timely completion of the contract work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... contract work. As prescribed in (TAR) 48 CFR 1222.101-71(a), insert the following clause: Strikes or Picketing Affecting Timely Completion of the Contract Work (OCT 1994) Notwithstanding any other provision... affecting timely completion of the contract work. 1252.222-70 Section 1252.222-70 Federal...

  15. 48 CFR 3052.222-70 - Strikes or picketing affecting timely completion of the contract work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Strikes or picketing affecting timely completion of the contract work. As prescribed in (HSAR) 48 CFR 3022... affecting timely completion of the contract work. 3052.222-70 Section 3052.222-70 Federal Acquisition... Contract Work (DEC 2003) Notwithstanding any other provision hereof, the Contractor is responsible...

  16. 48 CFR 3052.222-70 - Strikes or picketing affecting timely completion of the contract work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Strikes or picketing affecting timely completion of the contract work. As prescribed in (HSAR) 48 CFR 3022... affecting timely completion of the contract work. 3052.222-70 Section 3052.222-70 Federal Acquisition... Contract Work (DEC 2003) Notwithstanding any other provision hereof, the Contractor is responsible...

  17. 48 CFR 1252.222-70 - Strikes or picketing affecting timely completion of the contract work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... contract work. As prescribed in (TAR) 48 CFR 1222.101-71(a), insert the following clause: Strikes or Picketing Affecting Timely Completion of the Contract Work (OCT 1994) Notwithstanding any other provision... affecting timely completion of the contract work. 1252.222-70 Section 1252.222-70 Federal...

  18. Structures associated with strike-slip faults that bound landslide elements

    USGS Publications Warehouse

    Fleming, R.W.; Johnson, A.M.

    1989-01-01

    Large landslides are bounded on their flanks and on elements within the landslides by structures analogous to strike-slip faults. We observed the formation of thwse strike-slip faults and associated structures at two large landslides in central Utah during 1983-1985. The strike-slip faults in landslides are nearly vertical but locally may dip a few degrees toward or away from the moving ground. Fault surfaces are slickensided, and striations are subparallel to the ground surface. Displacement along strike-slip faults commonly produces scarps; scarps occur where local relief of the failure surface or ground surface is displaced and becomes adjacent to higher or lower ground, or where the landslide is thickening or thinning as a result of internal deformation. Several types of structures are formed at the ground surface as a strike-slip fault, which is fully developed at some depth below the ground surface, propagates upward in response to displacement. The simplest structure is a tension crack oriented at 45?? clockwise or counterclockwise from the trend of an underlying right- or left-lateral strike-slip fault, respectively. The tension cracks are typically arranged en echelon with the row of cracks parallel to the trace of the underlying strike-slip fault. Another common structure that forms above a developing strike-slip fault is a fault segment. Fault segments are discontinuous strike-slip faults that contain the same sense of slip but are turned clockwise or counterclockwise from a few to perhaps 20?? from the underlying strike-slip fault. The fault segments are slickensided and striated a few centimeters below the ground surface; continued displacement of the landslide causes the fault segments to open and a short tension crack propagates out of one or both ends of the fault segments. These structures, open fault segments containing a short tension crack, are termed compound cracks; and the short tension crack that propagates from the tip of the fault segment is typically oriented 45?? to the trend of the underlying fault. Fault segments are also typically arranged en echelon above the upward-propagating strike-slip fault. Continued displacement of the landslide causes the ground to buckle between the tension crack portions of the compound cracks. Still more displacement produces a thrust fault on one or both limbs of the buckle fold. These compressional structures form at right angles to the short tension cracks at the tips of the fault segments. Thus, the compressional structures are bounded on their ends by one face of a tension crack and detached from underlying material by thrusting or buckling. The tension cracks, fault segments, compound cracks, folds, and thrusts are ephemeral; they are created and destroyed with continuing displacement of the landslide. Ultimately, the structures are replaced by a throughgoing strike-slip fault. At one landslide, we observed the creation and destruction of the ephemeral structures as the landslide enlarged. Displacement of a few centimeters to about a decimeter was sufficient to produce scattered tension cracks and fault segments. Sets of compound cracks with associated folds and thrusts were produced by displacements of up to 1 m, and 1 to 2 m of displacement was required to produce a throughgoing strike-slip fault. The type of first-formed structure above an upward-propagating strike-slip fault is apparently controlled by the rheology of the material. Brittle material such as dry topsoil or the compact surface of a gravel road produces echelon tension cracks and sets of tension cracks and compressional structures, wherein the cracks and compressional structures are normal to each other and 45?? to the strike-slip fault at depth. First-formed structures in more ductile material such as moist cohesive soil are fault segments. In very ductile material such as soft clay and very wet soil in swampy areas, the first-formed structure is a throughgoing strike-slip fault. There are othe

  19. The Student Strike at the National Autonomous University of Mexico: A Political Analysis.

    ERIC Educational Resources Information Center

    Rhoads, Robert A.; Mina, Liliana

    2001-01-01

    Analyzes political tensions related to student strikes at the Universidad Nacional Autonoma de Mexico (UNAM), 1998-2000, which were sparked by proposed tuition fees. Discusses conflict between social justice sentiments focused on free and egalitarian access to higher education versus market-driven views promoting selective, competitive higher

  20. The Student Strike at the National Autonomous University of Mexico: A Political Analysis.

    ERIC Educational Resources Information Center

    Rhoads, Robert A.; Mina, Liliana

    2001-01-01

    Analyzes political tensions related to student strikes at the Universidad Nacional Autonoma de Mexico (UNAM), 1998-2000, which were sparked by proposed tuition fees. Discusses conflict between social justice sentiments focused on free and egalitarian access to higher education versus market-driven views promoting selective, competitive higher…

  1. Positive Psychologists on Positive Constructs

    ERIC Educational Resources Information Center

    Lyubomirsky, Sonja

    2012-01-01

    Comments on the original article by McNulty and Fincham (see record 2011-15476-001). In their article, the authors offered compelling evidence that constructs such as forgiveness and optimism can have both beneficial and adverse consequences, depending on the context. Their caution about labeling particular psychological processes as "positive" is…

  2. Positive Psychologists on Positive Constructs

    ERIC Educational Resources Information Center

    Lyubomirsky, Sonja

    2012-01-01

    Comments on the original article by McNulty and Fincham (see record 2011-15476-001). In their article, the authors offered compelling evidence that constructs such as forgiveness and optimism can have both beneficial and adverse consequences, depending on the context. Their caution about labeling particular psychological processes as "positive" is

  3. Pointing the SOFIA Telescope

    NASA Astrophysics Data System (ADS)

    Gross, M. A. K.; Rasmussen, J. J.; Moore, E. M.

    2010-12-01

    SOFIA is an airborne, gyroscopically stabilized 2.5m infrared telescope, mounted to a spherical bearing. Unlike its predecessors, SOFIA will work in absolute coordinates, despite its continually changing position and attitude. In order to manage this, SOFIA must relate equatorial and telescope coordinates using a combination of avionics data and star identification, manage field rotation and track sky images. We describe the algorithms and systems required to acquire and maintain the equatorial reference frame, relate it to tracking imagers and the science instrument, set up the oscillating secondary mirror, and aggregate pointings into relocatable nods and dithers.

  4. Intense hurricane strikes in southeastern New England since A.D. 1000

    NASA Astrophysics Data System (ADS)

    Donnelly, J. P.; Ettinger, R.; Cleary, P.

    2001-05-01

    Intense, category 3, 4, and 5 landfalling hurricanes pose a significant threat to lives and resources in coastal areas. Intense hurricane strikes also play a significant role in transporting sediments and shaping coastal landforms. Potential links between human-induced climate change and the frequency and intensity of tropical cyclones and the recent concentration of resources and population in areas where intense hurricanes may strike necessitate examination of decadal-to-millennial-scale variability in hurricane activity. The National Oceanic and Atmospheric Administration hurricane activity records for the western Atlantic Ocean only go back to the late 19th century. In the northeast United States historical records of hurricanes date back 370 years. We use stratigraphic evidence from coastal wetlands to extend the record of intense hurricane strikes into the prehistoric period in southeastern New England. Storm surge and wave action associated with intense storms can overtop barrier islands, remove sand and gravel from the beach and nearshore environment and deposit these sediments across the surface of coastal wetlands. In a regime of rising sea level, organic wetland sediments accumulate on top of these storm-induced deposits, preserving a record of past storms. We reconstructed storm deposition records within coastal marshes from eastern Connecticut to Cape Cod, Massachusetts. We matched these records to the historic record of storms and established the age of prehistoric storm deposits dating back about 1000 years with isotopic and stratigraphic dating techniques. The ages of storm deposits at all sites correlate to historic intense hurricane strikes. Prehistoric storm deposits can repeatedly be correlated among multiple sites and are of similar character and extent to the more recent deposits that we attribute to historic intense hurricane strikes. Therefore these older storm deposits were also likely deposited during prehistoric intense hurricanes. We documented at least eight deposits consistent with intense hurricane strikes in the last 1000 years. We identified deposits associated with historic intense hurricanes that occurred in A.D. 1954, 1938, 1869, 1815, 1638 and/or 1635. In addition we identified deposits likely associated with prehistoric intense hurricane strikes that occurred in A.D. 1400-1450, 1300-1400, and 1100-1150. These records indicate no apparent correlation between the frequency of intense hurricane landfalls in southeastern New England and the Little Ice Age and Medieval Warm Period climate oscillations.

  5. Analytic Study of Three-Dimensional Rupture Propagation in Strike-Slip Faulting with Analogue Models

    NASA Astrophysics Data System (ADS)

    Chan, Pei-Chen; Chu, Sheng-Shin; Lin, Ming-Lang

    2014-05-01

    Strike-slip faults are high angle (or nearly vertical) fractures where the blocks have moved along strike way (nearly horizontal). Overburden soil profiles across main faults of Strike-slip faults have revealed the palm and tulip structure characteristics. McCalpin (2005) has trace rupture propagation on overburden soil surface. In this study, we used different offset of slip sandbox model profiles to study the evolution of three-dimensional rupture propagation by strike -slip faulting. In strike-slip faults model, type of rupture propagation and width of shear zone (W) are primary affecting by depth of overburden layer (H), distances of fault slip (Sy). There are few research to trace of three-dimensional rupture behavior and propagation. Therefore, in this simplified sandbox model, investigate rupture propagation and shear zone with profiles across main faults when formation are affecting by depth of overburden layer and distances of fault slip. The investigators at the model included width of shear zone, length of rupture (L), angle of rupture (θ) and space of rupture. The surface results was follow the literature that the evolution sequence of failure envelope was R-faults, P-faults and Y-faults which are parallel to the basement fault. Comparison surface and profiles structure which were curved faces and cross each other to define 3-D rupture and width of shear zone. We found that an increase in fault slip could result in a greater width of shear zone, and proposed a W/H versus Sy/H relationship. Deformation of shear zone showed a similar trend as in the literature that the increase of fault slip resulted in the increase of W, however, the increasing trend became opposite after a peak (when Sy/H was 1) value of W was reached (small than 1.5). The results showed that the W width is limited at a constant value in 3-D models by strike-slip faulting. In conclusion, this study helps evaluate the extensions of the shear zone influenced regions for strike-slip faults.

  6. Using avian radar to examine relationships among avian activity, bird strikes, and meteorological factors

    USGS Publications Warehouse

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.; Laughlin, James A.

    2011-01-01

    Radar systems designed to detect avian activity at airfields are useful in understanding factors that influence the risk of bird and aircraft collisions (bird strikes). We used an avian radar system to measure avian activity at Beale Air Force Base, California, USA, during 2008 and 2009. We conducted a 2-part analysis to examine relationships among avian activity, bird strikes, and meteorological and time-dependent factors. We found that avian activity around the airfield was greater at times when bird strikes occurred than on average using a permutation resampling technique. Second, we developed generalized linear mixed models of an avian activity index (AAI). Variation in AAI was first explained by seasons that were based on average migration dates of birds at the study area. We then modeled AAI by those seasons to further explain variation by meteorological factors and daily light levels within a 24-hour period. In general, avian activity increased with decreased temperature, wind, visibility, precipitation, and increased humidity and cloud cover. These effects differed by season. For example, during the spring bird migration period, most avian activity occurred before sunrise at twilight hours on clear days with low winds, whereas during fall migration, substantial activity occurred after sunrise, and birds generally were more active at lower temperatures. We report parameter estimates (i.e., constants and coefficients) averaged across models and a relatively simple calculation for safety officers and wildlife managers to predict AAI and the relative risk of bird strike based on time, date, and meteorological values. We validated model predictability and assessed model fit. These analyses will be useful for general inference of avian activity and risk assessment efforts. Further investigation and ongoing data collection will refine these inference models and improve our understanding of factors that influence avian activity, which is necessary to inform management decisions aimed at reducing risk of bird strikes.

  7. Multiple strike slip faults sets: A case study from the Dead Sea transform

    NASA Technical Reports Server (NTRS)

    Ron, Hagai; Nur, Amos; Eyal, Y.

    1990-01-01

    In many strike slip tectonic settings, large rotations of crust blocks about vertical axes have been inferred from paleomagnetic data. These blocks are bounded by sets of parallel faults which presumably accommodate the relative motion between the blocks as regional deformation progress. A mechanical model by Nur et al., (1986) suggests that rotations greater than phi sub c equals 25 to 45 degrees must be accommodated by more than one set of faults, with angle phi sub c between their direction; consequently the sum of the angles between sets must be roughly equal to the total tectonic material rotation. To test this model, the authors investigated the fault geometry and field relation of fault sets in the Mt. Hermon area in northern Israel, where paleomagnetic declination implies data 69 degrees plus or minus 13 degrees counter-clockwise block rotation. The statistical and field relation analysis of over 315 faults shows that the faulting is predominantly right lateral strike slip consisting of three distinct sets. The oldest set strikes 253 degrees, the second oldest set strikes 293 degrees and the youngest strikes 339 degrees. This last direction is consistent also with the current north-south direction of the maximum principle stress axis. The angle phi sub c between the first and second sets is 39 degrees and between the second and third sets 46 degrees, in good agreement with the phi sub c angle predicted from mechanical considerations. The sum of the two angles is 85 degrees, in good agreement with the 69 degrees plus or minus 13 degrees CCW paleomagnetically derived rotation. The results suggest specifically that the sequential development of multiple intersecting fault sets is responsible for the faulting in the Mt. Hermon area; and generally that the model of block rotation with multiple faults provides very good simple rules for analyzing very complex fault patterns.

  8. Parkinsonian abnormality of foot strike: a phenomenon of ageing and/or one responsive to levodopa therapy?

    PubMed Central

    Hughes, J R; Bowes, S G; Leeman, A L; O'Neill, C J; Deshmukh, A A; Nicholson, P W; Dobbs, S M; Dobbs, R J

    1990-01-01

    1. Normally during walking, the heel strikes the ground before the forefoot. Abnormalities of foot strike in idiopathic Parkinson's disease may be amenable to therapy: objective measurements may reveal response which is not clinically apparent. Occult changes in foot strike leading to instability may parallel the normal, age-related loss of striatal dopamine. 2. The nature of foot strike was studied using pedobarography in 160 healthy volunteers, aged 15 to 91 years. Although 16% of strikes were made simultaneously by heel and forefoot, there were no instances of the forefoot preceding the heel. No significant effect of age on an index of normality of foot strikes was detected (P greater than 0.3). 3. The effect on foot strike of substituting placebo for a morning dose of a levodopa/carbidopa combination was studied in a double-blind, cross-over trial in 14 patients, aged 64 to 88 years, with no overt fluctuations in control of their idiopathic Parkinson's disease in relation to dosing. On placebo treatment there was a highly significant (P = 0.004) reduction in the number of more normal strikes, i.e. heel strikes plus simultaneous heel and forefoot strikes. The effect appeared unrelated to the corresponding difference between active and placebo treatments in plasma concentration of levodopa or a metabolite of long half-time, 3-O-methyldopa (3OMD). However, it correlated negatively (P less than 0.05) with the mean of the 3OMD concentrations. 4. It appears that some abnormalities of foot strike due to Parkinson's disease are reversible. Employing test conditions, designed to provoke abnormalities of foot strike, might be useful in screening for pre-clinical Parkinson's disease. PMID:2306409

  9. Positioning apparatus

    DOEpatents

    Vogel, M.A.; Alter, P.

    1983-07-07

    An apparatus is provided for precisely adjusting the position of an article relative to a beam emerging from a neutron source disposed in a housing. The apparatus includes a support pivotably mounted on a movable base plate and freely suspended therefrom. The support is gravity biased toward the housing and carries an article holder movable in a first direction longitudinally of the axis of said beam and normally urged into engagement against said housing. Means are provided for moving the base plate in two directions to effect movement of the suspended holder in two mutually perpendicular directions, respectively, normal to the axis of the beam.

  10. Positioning apparatus

    DOEpatents

    Vogel, Max A. (Kennewick, WA); Alter, Paul (Richland, WA)

    1986-01-01

    An apparatus for precisely positioning materials test specimens within the optimum neutron flux path emerging from a neutron source located in a housing. The test specimens are retained in a holder mounted on the free end of a support pivotably mounted and suspended from a movable base plate. The support is gravity biased to urge the holder in a direction longitudinally of the flux path against the housing. Means are provided for moving the base plate in two directions to effect movement of the holder in two mutually perpendicular directions normal to the axis of the flux path.

  11. Oligocene dextral strike-slip faulting in Anatolia: an early escape

    NASA Astrophysics Data System (ADS)

    Okay, A. I.; Satir, M.; Zattin, M.; Cavazza, W.; Topuz, G.

    2011-12-01

    The Early Eocene collision between the Eurasian and Anatolian plates in Turkey was followed by regional contraction, uplift, erosion and strike-slip faulting, which spanned the Late Eocene-Oligocene interval. This period ended abruptly in western Turkey in the Early Miocene by regional north-south extension and calc-alkaline magmatism. There are few rock records of the Late Eocene - Oligocene in western Anatolia, however, a major structure, active in this period between contraction and extension, was the NW-SE trending, right-lateral strike-slip Paleo-Eskisehir Fault with a length of over 225 km and a cumulative displacement of ca. 100 km. The ductile lower sections of the Paleo-Eskisehir Fault are exposed in the Uludag Massif, a NW-SE trending fault-bounded mountain range in northwest Turkey consisting of gneiss, amphibolite and marble. The Uludag Massif is characterized by NW-SE striking subvertical foliation and subhorizontal mineral stretching lineation with a dextral shear sense. The Rb/Sr muscovite and biotite ages from the Uludag Massif are Eocene (ca. 49 Ma) and Oligocene (36-30 Ma), respectively. The metamorphic rocks are intruded by a tectonically foliated subvertical Oligocene (ca. 33 Ma) granitic dyke, 17 km long and only 1.5 km wide, with subhorizontal mineral stretching lineation. A 27 Ma post-kinematic granite marks the termination of the shear zone activity. The apatite fission track (AFT) ages from the crystalline rocks are Early Miocene (ca. 20 Ma). Large gneiss clasts derived from the Uludag Massif are found in the adjacent Miocene basin. The 14 Ma AFT age from a gneiss clast from the Miocene basin show that the Uludag Massif was on the surface by the Middle Miocene. These data constrain the strike-slip faulting along the Paleo-Eskisehir Fault to the Late Eocene-Oligocene (38-27 Ma). The exhumation of the Uludag Massif occurred in the Early Miocene and post-dates the strike-slip activity. Although the Paleo-Eskisehir Fault is comparable in length and total offset with large continental strike-slip faults there are few basins associated with it. The only ones are small Oligocene (26 Ma) strike-slip basins with continental fan conglomerates and lacustrine tuffs with a total thickness of less than 500 meters. The scarcity of strike-slip basins along the Paleo-Eskisehir Fault is probably due to its transpressional character and/or subsequent erosion. The case of the Paleo-Eskisehir Fault indicate that during the Late Eocene-Oligocene crustal-scale right-lateral strike-slip faults were transporting crustal fragments from Anatolia into the north-south extending Aegean, with the implication that the westward translation of Turkey, related to the Hellenic slab retreat, started earlier than the Miocene Arabia-Eurasia collision.

  12. Geomorphic expression of strike-slip faults: field observations vs. analog experiments: preliminary results

    NASA Astrophysics Data System (ADS)

    Hsieh, S. Y.; Neubauer, F.; Genser, J.

    2012-04-01

    The aim of this project is to study the surface expression of strike-slip faults with main aim to find rules how these structures can be extrapolated to depth. In the first step, several basic properties of the fault architecture are in focus: (1) Is it possible to define the fault architecture by studying surface structures of the damage zone vs. the fault core, particularly the width of the damage zone? (2) Which second order structures define the damage zone of strike-slip faults, and how relate these to such reported in basement fault strike-slip analog experiments? (3) Beside classical fault bend structures, is there a systematic along-strike variation of the damage zone width and to which properties relates the variation of the damage zone width. We study the above mentioned properties on the dextral Altyn fault, which is one of the largest strike-slip on Earth with the advantage to have developed in a fully arid climate. The Altyn fault includes a ca. 250 to 600 m wide fault valley, usually with the trace of actual fault in its center. The fault valley is confined by basement highs, from which alluvial fans develop towards the center of the fault valley. The active fault trace is marked by small scale pressure ridges and offset of alluvial fans. The fault valley confining basement highs are several kilometer long and ca. 0.5 to 1 km wide and confined by rotated dextral anti-Riedel faults and internally structured by a regular fracture pattern. Dextral anti-Riedel faults are often cut by Riedel faults. Consequently, the Altyn fault comprises a several km wide damage zone. The fault core zone is a barrier to fluid flow, and the few springs of the region are located on the margin of the fault valley implying the fractured basement highs as the reservoir. Consequently, the southern Silk Road was using the Altyn fault valley. The preliminary data show that two or more orders of structures exist. Small-scale develop during a single earthquake. These finally accumulate to a several 100 m wide fault core, which is in part exposed at surface to arid climate and a km wide damage zone. The basic structures of analog experiments can be well transferred to nature, although along strike changes are common due to fault bending and fracture failure of country rocks.

  13. First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)

    SciTech Connect

    Serianni, G. De Muri, M.; Veltri, P.; Bonomo, F.; Chitarin, G.; Pasqualotto, R.; Pavei, M.; Rizzolo, A.; Valente, M.; Muraro, A.; Franzen, P.; Ruf, B.; Schiesko, L.

    2014-02-15

    The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.

  14. Evidence of Right Lateral Strike-slip Active Fault in Kangra Valley, NW Himalaya, India

    NASA Astrophysics Data System (ADS)

    Malik, J. N.; Sahoo, S.; Okumura, K.; Mohanty, A.; Naik, S. P.

    2013-12-01

    Kangra valley located in Himachal Pradesh, NW Himalaya falls under meizoseismal zone of 1905 Kangra earthquake (Mw=7.8). Till date no surface rupture has been reported, however few studies suggest that probable rupture along Jawalamukhi Thrust (JMT) located at south of Kangra valley. In present study we report newly identified right lateral strike-slip active fault trace striking WNW-ESE, named as 'Kangra Valley Fault'. The fault has displaced young alluvial fan surface and fluvial terrace in Kangra Valley. High resolution CARTOSAT - 1 data and CORONA photo interpretation revealed prominent offset of streams, alluvial fan surfaces and fluvial terraces. Ground Penetrating Radar (GPR) survey and trenches excavated across 1 m high fault scarp also revealed occurrence of paleo-earthquake during recent historic period. We have been able to trace this fault for a distance of ~40 km. Further result will play a vital role towards seismic hazard evaluation of this area.

  15. Predator strike shapes antipredator phenotype through new genetic interactions in water striders

    PubMed Central

    Armisn, David; Nagui Refki, Peter; Crumire, Antonin Jean Johan; Viala, Sverine; Toubiana, William; Khila, Abderrahman

    2015-01-01

    How novel genetic interactions evolve, under what selective pressures, and how they shape adaptive traits is often unknown. Here we uncover behavioural and developmental genetic mechanisms that enable water striders to survive attacks by bottom-striking predators. Long midlegs, critical for antipredator strategy, are shaped through a lineage-specific interaction between the Hox protein Ultrabithorax (Ubx) and a new target gene called gilt. The differences in leg morphologies are established through modulation of gilt differential expression between mid and hindlegs under Ubx control. Furthermore, short-legged water striders, generated through gilt RNAi knockdown, exhibit reduced performance in predation tests. Therefore, the evolution of the new Ubxgilt interaction contributes to shaping the legs that enable water striders to dodge predator strikes. These data show how divergent selection, associated with novel preypredator interactions, can favour the evolution of new genetic interactions and drive adaptive evolution. PMID:26323602

  16. Striking Oxygen Sensitivity of the Peptidylglycine ?-Amidating Monooxygenase (PAM) in Neuroendocrine Cells.

    PubMed

    Simpson, Peter D; Eipper, Betty A; Katz, Maximiliano J; Gandara, Lautaro; Wappner, Pablo; Fischer, Roman; Hodson, Emma J; Ratcliffe, Peter J; Masson, Norma

    2015-10-01

    Interactions between biological pathways and molecular oxygen require robust mechanisms for detecting and responding to changes in cellular oxygen availability, to support oxygen homeostasis. Peptidylglycine ?-amidating monooxygenase (PAM) catalyzes a two-step reaction resulting in the C-terminal amidation of peptides, a process important for their stability and biological activity. Here we show that in human, mouse, and insect cells, peptide amidation is exquisitely sensitive to hypoxia. Different amidation events on chromogranin A, and on peptides processed from proopiomelanocortin, manifest similar striking sensitivity to hypoxia in a range of neuroendocrine cells, being progressively inhibited from mild (7% O2) to severe (1% O2) hypoxia. In developing Drosophila melanogaster larvae, FMRF amidation in thoracic ventral (Tv) neurons is strikingly suppressed by hypoxia. Our findings have thus defined a novel monooxygenase-based oxygen sensing mechanism that has the capacity to signal changes in oxygen availability to peptidergic pathways. PMID:26296884

  17. First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE)

    NASA Astrophysics Data System (ADS)

    Serianni, G.; De Muri, M.; Muraro, A.; Veltri, P.; Bonomo, F.; Chitarin, G.; Pasqualotto, R.; Pavei, M.; Rizzolo, A.; Valente, M.; Franzen, P.; Ruf, B.; Schiesko, L.

    2014-02-01

    The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions.

  18. First negative ion beam measurement by the Short-Time Retractable Instrumented Kalorimeter Experiment (STRIKE).

    PubMed

    Serianni, G; De Muri, M; Muraro, A; Veltri, P; Bonomo, F; Chitarin, G; Pasqualotto, R; Pavei, M; Rizzolo, A; Valente, M; Franzen, P; Ruf, B; Schiesko, L

    2014-02-01

    The Source for Production of Ion of Deuterium Extracted from Rf plasma (SPIDER) test facility is under construction in Padova to optimise the operation of the beam source of ITER neutral beam injectors. The SPIDER beam will be characterised by the instrumented calorimeter STRIKE, whose main components are one-directional carbon-fibre-carbon-composite tiles. A small-scale version of the entire system has been employed in the BAvarian Test MAchine for Negative ions (BATMAN) testbed by arranging two prototype tiles in the vertical direction. The paper presents a description of the mini-STRIKE system and of the data analysis procedures, as well as some results concerning the BATMAN beam under varying operating conditions. PMID:24593470

  19. Accelerations due to impact at heel strike using below-knee prosthesis.

    PubMed

    Van Jaarsveld, H W; Grootenboer, H J; De Vries, J

    1990-08-01

    The acceleration in the sagittal plane of the prosthetic tube at heel strike in normal walking was measured in five healthy amputees with their definitive below-knee prosthesis, every subject using six different prosthetic feet, wearing sport shoes as well as leather shoes. The experiments were carried out in the rehabilitation centre "Het Roessingh", Enschede, The Netherlands. Maximum accelerations were extracted from the acceleration-time-signal. Mean acceleration maxima of all subjects were calculated for each foot-shoe combination to eliminate the individual influence of the subjects. In the axial direction the maximal accelerations demonstrate a clear difference among the prosthetic feet and the shoes, while in dorsoventral (tangential) direction the inter-individual variation in the acceleration extremes dominates the difference between the types of footwear. In comparison with non-amputees the magnitude of the maximal axial acceleration at heel strike does not differ significantly. PMID:2235301

  20. Simulating Damage Due to a Lightning Strike Event: Effects of Temperature Dependent Properties on Interlaminar Damage

    NASA Technical Reports Server (NTRS)

    Ghezeljeh, Paria Naghipour; Pineda, Evan Jorge

    2014-01-01

    A multidirectional, carbon fiber-epoxy, composite panel is subjected to a simulated lightning strike, within a finite element method framework, and the effect of material properties on the failure (delamination) response is investigated through a detailed numerical study. The numerical model of the composite panel consists of individual homogenized plies with user-defined, cohesive interface elements between them. Lightning strikes are simulated as an assumed combination of excessive heat and high pressure loadings. It is observed that the initiation and propagation of lightning-induced delamination is a significant function of the temperature dependency of interfacial fracture toughness. This dependency must be defined properly in order to achieve reliable predictions of the present lightning-induced delamination in the composite panel.

  1. Role of strike-slip faulting in the evolution of allochthonous terranes in the Philippines

    SciTech Connect

    Karig, D.E.; Sarewitz, D.R.; Haeck, G.D.

    1986-10-01

    Concepts of allochthonous terrane transport and emplacement are dominated by the assumption that most terranes originate on the subducting plate, collide with the upper plate, and are emplaced there. Movement of terranes along the convergent margin is recognized but is generally attributed to postcollision slip. In the northern Philippines, allochthonous terranes originate primarily within the arc system, have been translated along it by strike-slip faults, and were emplaced by cessation of that slip. The authors suggest that in the Philippines some originally vertical strike-slip boundaries may have evolved into shallow-dipping sutures marked by fold and thrust systems. This mode of terrane evolution may be more common than generally appreciated, particularly in orogenic belts developed in response to oblique convergence.

  2. Tectonics of the Western Betics: the role of E-W strike slip fault corridors

    NASA Astrophysics Data System (ADS)

    Frasca, Gianluca; Gueydan, Frdric; Brun, Jean-Pierre; Clrier, Bernard

    2014-05-01

    The tectonic origin of the arcuate Betic-Rif orogenic belt that surrounds the Alboran Sea at the western tip of the Mediterranean Sea remains debated. Here, we investigate the tectonic units cropping out in the Western Betics (Malaga region, Southern Spain) with the main goal of reconstructing the Oligo-Miocene evolution of the area. New structural data and geological mapping together with available data allow us to identify the main structural features of the area. Deformation is found to be extremely diffused but two E-W elongated tectonic blocks with different lithological composition are outlined by marked E-W dextral strike-slip corridors ending up in horse-tail splays. These E-W strike slip corridors are responsible for late Miocence tectonics of both the internal and external zones of the Betic Cordillera.

  3. Investigating Stress Seources and Fault Parameters Along Major Strike-Slip Lineae on Europa

    NASA Astrophysics Data System (ADS)

    Cameron, M. E.; Smith-Konter, B. R.; Pappalardo, R. T.

    2014-12-01

    The surface of Europa is crosscut by a dense network of structures, many of these representing a complex history of strike-slip tectonic activity, presumably arising from a combination of global and local stress sources. Several dominant (~1000 km) structures span geographically diverse locations of Europa, offering a unique opportunity to study strike-slip activity at the hemispheric scale. These structures also exhibit kilometer-scale geometric bends that can promote or discourage shear failure. To better understand the role of tidal stress sources and implications for strike-slip faulting on Europa, we investigate the relationship between shear and normal stresses at four major fault zones: Agenor Linea, Rhadamanthys Linea, Conamara Chaos (Agave and Asterius Lineae), and Astypalaea Linea. Assuming tidal diurnal and non-synchronous rotation (NSR) stresses as the primary mechanisms for strike-slip tectonism, here we investigate the mechanics of Coulomb shear failure on Europa. We consider a range of friction coefficients (µf = 0.2 - 0.6) and fault depths (0 - 6 km) to evaluate how the predicted failure varies as a function of depth and its dependency on ice friction, geographic location, and fault geometry. Our results indicate that the conditions for failure at depth are not met for any of the lineae if subject to diurnal stresses only. Alternatively, models that include both diurnal and NSR stresses readily generate stress magnitudes that could permit shear failure. Shear failure is easily activated and extends to depths ranging from 3 - 6 km on all four linea systems when a low coefficient of friction (µf = 0.2) is assumed, but is generally limited to depths < 3 km when a high coefficient of friction (µf = 0.6) is applied. Based on these results, we infer that the conditions for shear failure are potentially met along at least these four studied lineae, and possibly others, on Europa when NSR is adopted as a driving stress mechanism and the coefficient of friction is low.

  4. Evaluation of Blade-Strike Models for Estimating the Biological Performance of Large Kaplan Hydro Turbines

    SciTech Connect

    Deng, Zhiqun; Carlson, Thomas J.; Ploskey, Gene R.; Richmond, Marshall C.

    2005-11-30

    BioIndex testing of hydro-turbines is sought as an analog to the hydraulic index testing conducted on hydro-turbines to optimize their power production efficiency. In BioIndex testing the goal is to identify those operations within the range identified by Index testing where the survival of fish passing through the turbine is maximized. BioIndex testing includes the immediate tailrace region as well as the turbine environment between a turbine's intake trashracks and the exit of its draft tube. The US Army Corps of Engineers and the Department of Energy have been evaluating a variety of means, such as numerical and physical turbine models, to investigate the quality of flow through a hydro-turbine and other aspects of the turbine environment that determine its safety for fish. The goal is to use these tools to develop hypotheses identifying turbine operations and predictions of their biological performance that can be tested at prototype scales. Acceptance of hypotheses would be the means for validation of new operating rules for the turbine tested that would be in place when fish were passing through the turbines. The overall goal of this project is to evaluate the performance of numerical blade strike models as a tool to aid development of testable hypotheses for bioIndexing. Evaluation of the performance of numerical blade strike models is accomplished by comparing predictions of fish mortality resulting from strike by turbine runner blades with observations made using live test fish at mainstem Columbia River Dams and with other predictions of blade strike made using observations of beads passing through a 1:25 scale physical turbine model.

  5. The Attenuation of Strike Acceleration with the Use of Safety Equipment in Tae Kwon Do

    PubMed Central

    Gupta, Sanjey

    2011-01-01

    Purpose The objectives of this study include: (1) Determination of the attenuation of strike acceleration that Tae Kwon Do sparring safety pads provide from kicks from Olympic style TKD fighters, (2) The sex and weight differentiation in acceleration achieved within the thorax model with the roundhouse kicks. Methods This prospective, observational study utilized 15 Olympic style fighters from an elite team kicking a water core heavy bag thorax model with roundhouse kicks. The model was fitted with a tri-axial accelerometer (GCDC, model X250-2) to measure g acceleration from strikes to the bag. The bag was kicked in three, 10 kick phases by all subjects: kicks without padding; kicks with hogu on heavy bag, and kicks with hogu and instep guards on feet. The g acceleration readings were recorded in all phases. Results Kolmogorov-Smirnov failed for all variables. There were 8 female subjects: median age 14 years, median weight 53.4 kg and 7 male subjects: median age 17 years, median weight 70.45 kg. The ANOVA on ranks of the acceleration from kicks against the bag achieved significance, P=0.001. Spearman rank order correlation between the weights of players and acceleration of strike against the hogu without and with insteps pads was significant, P=0.035/r=0.54 and P=0.018/r=0.59, respectively. Conclusion Heavier and male subjects tend to produce more force in strikes. Protective chest guard reduces acceleration to the thorax model, but the utility of instep guards is questionable. PMID:22375244

  6. Poroelastic Shear Stresses Below Injection Target Intervals Encourage Vertical Strike-Slip Earthquakes

    NASA Astrophysics Data System (ADS)

    Roeloffs, E. A.

    2014-12-01

    Waste-fluid injection into sedimentary rock is believed to have induced strike-slip earthquakes on historically inactive near-vertical faults in underlying crystalline basement beneath Youngstown, Ohio in 2011 (Kim, 2013). Two other examples of vertical strike-slip basement seismicity - the 1986 M4.8 earthquake near Painesville, Ohio (Nicholson et al., 1988) and sequences near Ashtabula, Ohio between 1986 and 2003 (Seeber et al., 2004) - were likely induced, although the Painesville event occurred 12 km from the nearest active injection well, and the Ashtabula activity persisted for years after injection ceased. In each case, hypocenters were about 1 km deeper than injection zones, prompting the hypothesis that fluid flow along faults triggered earthquakes by raising hypocentral fluid pressure. While a M4-5 earthquake likely requires a pre-existing fault 0.5-1 km in extent, favorably oriented in the pre-existing stress field, high fault-zone hydraulic conductivity has not been demonstrated. Assuming faults affect neither fluid flow nor the stress field, a layered axisymmetric finite element model (implemented in COMSOL) can simulate coupled poroelastic stress and pore-pressure distributions in isotropic, homogeneous basement with higher stiffness and lower permeability than target injection zones. Simulated radial and tangential poroelastic stresses resolved onto vertical planes lead to Coulomb stress changes favoring strike slip on portions of such planes beneath the injection zone. More specifically, the maximum horizontal shear stress increment on a vertical fault occurs where a line to the well is at 45 to the fault. The maximum shear strain is of opposite sense in adjacent quadrants, possibly explaining activation of en echelon faults in Youngstown, Ohio. Similar configurations of the wells, faults, and earthquakes in these case histories suggests that poroelastic stresses can govern the locations of strike-slip earthquakes on basement faults.

  7. Lower Miocene coeval thrusting and strike-slip faulting in the Western Betics

    NASA Astrophysics Data System (ADS)

    Frasca, Gianluca; Gueydan, Frdric; Brun, Jean-Pierre

    2015-04-01

    In the framework of the Africa-Europe convergence, the Mediterranean system presents a complex interaction between subduction rollback and upper subduction plate deformation since 30 Ma. The western end of the system shows an arcuate geometry across the Gibraltar arc, the Betico-Rifean belt, in which the relationship between slab dynamics and onshore tectonics is poorly constrained. The present study focuses on the Western Betics, which is characterized by two major thrusts: 1/ the Alboran Front limits the metamorphic domain (Alboran Domain) from the fold-and-thrust belts involving the Mesozoic cover of the Iberian margin (Subbetics Domain); 2/ the Alboran Internal Thrust allows the juxtaposition of a strongly attenuated lithosphere section, containing the large Ronda subcontinental mantle bodies, on top of crustal rocks. New structural data show that two major E-W strike-slip corridors controlled the deformation pattern of the Alboran Domain, in which E-W dextral strike-slip faults, N60 thrusts and N140 normal faults developed simultaneously during dextral strike-slip simple shear. The Alozaina piggy-back Basin, mainly formed by olistotromic deposits of Lower Miocene age, provides an age estimate for the continuous westward translation of the Alboran Domain, with reference to Iberia, that is accommodated mainly by an E-W lateral strike-slip ramp and a N60 frontal thrust ramp. In this context, a thrust sequence led to the piling up of thrust units in the Western Betics and to the crustal emplacement of the Ronda Peridotites bodies.

  8. Dextral strike-slip tectonism and arc processes in the Sierra Nevada and Idaho batholiths

    NASA Astrophysics Data System (ADS)

    Tikoff, B.; Byerly, A.; Gaschnig, R. M.; Vervoort, J. D.; Kelso, P. R.

    2014-12-01

    Both the Sierra Nevada (CA) and Idaho batholiths display clear evidence for magmatism simultaneous with dextral strike-slip movement during the Cretaceous. There is, however, a significant difference between both the style and the timing of the deformation and magmatism in these two magmatic arcs. The Sierra Nevada displays dextral strike-slip tectonism active from 92-80 Ma, as evidenced by a series of dextral shear zones associated with the axis of active magmatism. The concept of the plutons intruding en echelon pull-apart structures in a dextral system has been supported by the recognition of widespread, syn-tectonic shear zones along the axis of the arc. Further, a modern analog can be found in El Salvador, where dextral translation of the forearc has resulted in en echelon dextral shearing in a magmatic arc dominated by arc-perpendicular normal faulting. In contrast, dextral tectonism in Idaho both starts (~103 Ma) and ceases earlier (~90 Ma) than strike-slip motion in the Sierra Nevada batholith. Further, the deformation is better developed, as recorded by the ~5 km thick, dextral transpressional western Idaho shear zone (WISZ). The WISZ deformation affects I-type magmas that are not typically considered part of the Idaho batholith. The main phase of the 85-70 Ma, peraluminous Idaho batholith (Atlanta lobe) only contains local evidence for dextral shearing, such as the NS-oriented Johnson Creek-Profile Gap shear zone. The reasons for this along-strike variation in deformation for Cretaceous magmatic arcs in North America may relate to the collisional and translation histories of offshore terranes.

  9. Civil helicopter wire strike assessment study. Volume 2: Accident analysis briefs

    NASA Technical Reports Server (NTRS)

    Tuomela, C. H.; Brennan, M. F.

    1980-01-01

    A description and analysis of each of the 208 civil helicopter wire strike accidents reported to the National Transportation Safety Board (NTSB) for the ten year period 1970-1979 is given. The accident analysis briefs were based on pilot reports, FAA investigation reports, and such accident photographs as were made available. Briefs were grouped by year and, within year, by NTSB accident report number.

  10. Assessing the risk of ships striking large whales in marine spatial planning.

    PubMed

    Redfern, J V; McKenna, M F; Moore, T J; Calambokidis, J; Deangelis, M L; Becker, E A; Barlow, J; Forney, K A; Fiedler, P C; Chivers, S J

    2013-04-01

    Marine spatial planning provides a comprehensive framework for managing multiple uses of the marine environment and has the potential to minimize environmental impacts and reduce conflicts among users. Spatially explicit assessments of the risks to key marine species from human activities are a requirement of marine spatial planning. We assessed the risk of ships striking humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and fin (Balaenoptera physalus) whales in alternative shipping routes derived from patterns of shipping traffic off Southern California (U.S.A.). Specifically, we developed whale-habitat models and assumed ship-strike risk for the alternative shipping routes was proportional to the number of whales predicted by the models to occur within each route. This definition of risk assumes all ships travel within a single route. We also calculated risk assuming ships travel via multiple routes. We estimated the potential for conflict between shipping and other uses (military training and fishing) due to overlap with the routes. We also estimated the overlap between shipping routes and protected areas. The route with the lowest risk for humpback whales had the highest risk for fin whales and vice versa. Risk to both species may be ameliorated by creating a new route south of the northern Channel Islands and spreading traffic between this new route and the existing route in the Santa Barbara Channel. Creating a longer route may reduce the overlap between shipping and other uses by concentrating shipping traffic. Blue whales are distributed more evenly across our study area than humpback and fin whales; thus, risk could not be ameliorated by concentrating shipping traffic in any of the routes we considered. Reducing ship-strike risk for blue whales may be necessary because our estimate of the potential number of strikes suggests that they are likely to exceed allowable levels of anthropogenic impacts established under U.S. laws. PMID:23521668

  11. Striking behavior of photoneutron cross sections for {sup 90}Zr near threshold

    SciTech Connect

    Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Iwamoto, C.; Itoh, O.; Kamata, M.; Io, M.; Kususe, K.; Teramoto, T.; Goriely, S.; Harada, H.; Kitatani, F.; Goko, S.; Toyokawa, H.; Yamada, K.; Lui, Y.-W.

    2011-10-28

    Photoneutron cross sections for {sup 90}Zr near neutron threshold were examined with a photon difference technique using laser Compton scattering {gamma}-ray beams. The cross section decreasing in the vicinity of neutron threshold exhibited a steep rise within 150 keV above the threshold. We draw attention to a possible relation of this striking behavior to the 3P valence neutron resonance known in neutron capture in the mass region A{approx_equal}90.

  12. Statistical determination of mean strike and dip: example from basal Tuscaloosa, Eastern Alabama

    SciTech Connect

    Pontigo, F.A. Jr.; Parker, W.C.; Tanner, W.F.

    1983-09-01

    An unconformity may be a very complicated surface. However, the use of trend surface analysis permits (a) determination of the best fit plane which represents the strike and dip for the region studied; and (b) evaluation of local departures from that plane, in terms of paleotopography. This procedure has been demonstrated in a study of the basal contact of the Tuscaloosa Group with an underlying variably weathered gneiss complex, which was sampled at 17 localties in Macon and Tallapoosa Counties (Notasulga Quadrangle), Alabama. At each locality the elevation and nature of the basal Tuscaloosa contact was recorded along with lithologic observations. A trend surface analysis was used to generate a first order regression plane. This plane represents mean strike and dip of the unconformity; it strikes N81/sup 0/W and dips 0.61/sup 0/SW. This result is highly significant (F/sub 2,14/ = 190.5; N = 17) and accounts for 96% of the variance in elevation (R/sup 2/ = 0.965). First order residuals plotted against map location reveal little regional trend. However, mapping of basal Tuscaloosa grain-size data onto the residuals reveals a preponderance of coarse material at localities with negative residuals. This indicates the expected preferences for coarse (gravel) deposition in paleotopographic lows. Mapping the weathered state of the underlying gneiss onto the residuals reveals no pattern, suggesting that much of the alteration of this unit postdated the unconformity. These results, although on a simple data set, illustrate the utility of the technique to stratigraphic problems involving mean strike and dip.

  13. 77 FR 38595 - Taking and Importing Marine Mammals; Precision Strike Weapon and Air-to-Surface Gunnery Training...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ...; Precision Strike Weapon and Air-to-Surface Gunnery Training and Testing Operations at Eglin Air Force Base... with Precision Strike Weapon (PSW) and Air-to-Surface (AS) gunnery missions, both of which are military... two weapons: (1) The Joint Air-to-Surface Stand-off Missile (JASSM) AGM-158 A and B; and (2) the...

  14. The Right to Strike for Pennsylvania's Public Employees--Its Scope, Limits and Ramifications for the Public Employer.

    ERIC Educational Resources Information Center

    Decker, Kurt H.

    1978-01-01

    Examines the impact of private labor rulings on Pennsylvania's public employee laws, public sector strikes and their implications, and Pennsylvania's public employee laws and the right to strike. Available from Duquesne Law Review, 901 Rockwell Hall, 600 Forbes Avenue, Pittsburgh, PA 15219; sc $3.50. (Author/IRT)

  15. Drainage Pattern, Along-Strike Topography and Three-Dimensional Construction of the Himalayan orogen

    NASA Astrophysics Data System (ADS)

    Yin, A.

    2005-12-01

    Past studies on the Himalayan orogen have mostly emphasized its 2-D evolution in cross-section view. As a result, how the orogen has grown in 3-D remains poorly understood. For example, it is not clear if the >1500-km long Main Central Thrust (MCT) and Main Boundary Thrust (MBT) were initiated synchronously along the whole orogen or started at one segment and then propagated laterally during subsequent fault motion. To clarify this issue, I examined the Himalayan drainage pattern, along-strike topography, and geometry and kinematics of growing contractional structures across both the Himalayan front and the Shillong Plateau. The main observations may be summarized as follows. (1) The five rivers that cut across the Himalaya are arranged approximately symmetric with respect to the Himalayan-arc axis (~85 E): the Arun River (87 E) is in the middle with the Sutlej (77 E) and Indus (72 E) Rivers in the west and the Subansiri (93 E) and Yalu-Brahmaputra (96 E) Rivers in the east. (2) Between the eastern and western syntaxes, south-flowing drainages east of 85.5 E are consistently deflected to the east by east-growing anticlines and thrusts, whereas drainages west of 85.5E are deflected systematically to the west by west-growing anticlines and thrusts along the Himalayan front. The only region where no drainage deflection is observed is the Bhutan Himalaya. There all rivers flow straight across the Himalayan front. (3) The deflected drainage pattern indicates that the Shillong Plateau south of the eastern Himalaya has been growing westward. (4) The along-crest Himalayan topographic profile concaves downward, starting from ~5200 m just inside the two syntaxes and reaching 8848 m at Mt. Everest (~87 E). (5) There are a total of 17 major growing contractional structures in the Main Frontal Thrust Zone (MFTZ), with 10 in the west and 7 in the east. Each structure has a length between ~20 km and >150 km, but the west-growing structures in the west are significantly longer (with four > 150 km) than the east-growing structures (all of them < 70 km). The above observations have the following implications. (A) The Main Frontal Thrust Zone consists of a series of en echelon folds and thrusts instead of being a single thrust. The en echelon arrangement of contractional structures indicates that a significant component of right-slip and left-slip motion occurs along the western and eastern limbs of the Himalayan arc. The sense of shearing indicates that the Himalayan arc has been progressively tightened. (B) The MFTZ was initiated in the middle segment of the Himalayan arc and has subsequently propagated laterally to the east and west. (C) The eastward increase in convergence velocity between India and Asia has played a minor role in controlling the late Cenozoic development of the Himalayan arc. That is, the divide for both the easterly and westerly deflected Himalayan drainages and east- and west-growing structures only departs from the central Himalayan-arc axis for ~1 to the east. Similarly, the highest point in the along-crest topographic profile only deviates ~2 east of the arc axis. I suggest that the eastward increase in convergence rate between India and Asia has been accommodated partially by the west-growing Shillong Plateau along the north-dipping Dauki thrust. That is, the thrust has absorbed extra shortening in the eastern Himalaya resulting from this asymmetric boundary condition. (D) In light of the late Cenozoic development of the MFTZ and the Dauki thrust, the Himalayan orogen may have been constructed by alternation or coeval development of structures initiating either in its center or at one of its two ends.

  16. Strikes and the National Health Service: Some legal and ethical issues

    PubMed Central

    Dworkin, Gerald

    1977-01-01

    This paper is sadly opportune. The general public is angry and bewildered if not hurt by the variety of strikes which are brought more or less forcibly to their attention. People used to understand what lay behind a strike - a demand for more pay, better conditions - but today a political element often intrudes, and it is this that worries those who ask themselves whether this or that dispute is either lawful or morally acceptable. Professor Dworkin, a lawyer, first sets out the legal issues surrounding strikes and then advances the ethical arguments, closely relating them to the legal framework. The most interesting part of the paper, however, may well be that devoted to the moral obligation of example, in particular the example to be set by members of the medical profession and by all those caring for the sick. As public attitudes to industrial disputes `become dulled and quiescent' it is absolutely necessary that there should be a reappraisal of the moral standards of the past which coincide with a respect for the law. In the last century the term `anomie' was used to describe a `society which has shaken off its former restraints such as religion, respect for law and order and a definite moral code as to what is right and wrong'. We are living in that sort of society today, and one need not be a professional `ethicist' to recognize the signs, and hopefully, to work for the return of `ethical' values. PMID:874982

  17. Sequential motions of body segments in striking and throwing skills: descriptions and explanations.

    PubMed

    Putnam, C A

    1993-01-01

    The motions of segments participating in striking and throwing skills are generally sequenced in a proximal-to-distal fashion. These sequences are often described in terms of the linear velocities of the segment endpoints, joint angular velocities or segment angular velocities. While each method of description has its own merit, the latter is recommended since it leads to an intuitively pleasing way of explaining segment motions. Explanations of segment motion sequences are dependent not only on a knowledge of the joint moments driving the system of linked segments, but on the way the segments interact as functions of their motions and orientations. The motion-dependent interaction among segments is significant and offers an explanation of the sequencing of segment motions. As illustrated by the thigh and lower leg in kicking and by the upper arm and forearm in overarm pitching, the forward acceleration of the proximal segment plays a large role in causing the distal segment to lag behind. The subsequent forward acceleration of the distal segment is largely a result of the way the proximal segment interacts with the distal segment as a function of the proximal segment's angular velocity. The proximal segment is subsequently slowed down largely due to the motion-dependent effect of the distal segment on the proximal segment. Differences in the way segments interact in striking and throwing skills can account for variations in the timing of segment actions and these differences need to be examined before establishing general principles governing striking and throwing. PMID:8505347

  18. Delimitated strike artifacts from FBP using a robust morphological structure operation

    NASA Astrophysics Data System (ADS)

    Chen, Tai-Been; Chen, Huei-Yung; Lin, Ming-Chia; Lin, Li-Wei; Lu, Nan-Han; Tsai, Fan-Shiu; Huang, Yung-Hui

    2014-04-01

    When using cardiac nuclear medicine images for diagnosis, the filtered back-projection (FBP) algorithm can reconstruct positron emission tomography (PET) images under low count rates. However, background strike artifacts in PET images are affected by diagnostic judgment. Hence, this study developed a robust method of removing background strike artifacts from FBP images without reducing image quality. A Jaszczak anthropomorphic torso phantom and a laboratory rabbit were used for performance tests of the proposed method. Parallel computing was applied to optimize the mask size of morphological structure operator (MSO) by minimizing the background standard deviation (Std). The optimal MSO mask size for the evaluated Jaszczak phantom was 33. The FBP images processed by MSO had significantly reduced strike artifacts measured by background Std (P=1E-5). After MSO processing, the time activity curve (TAC) of FBP images was stable and resembled the original FBP images (P=0.5). The proposed approach is highly stable and reduces noise by 13.082.32 in FBP images after MSO processing with 33 mask.

  19. Influence of erosion and sedimentation on strike-slip fault systems: insights from analogue models

    NASA Astrophysics Data System (ADS)

    Le Guerrou, Erwan; Cobbold, Peter Robert

    2006-03-01

    We describe 18 experiments on the formation of strike-slip fault systems in sand. All models were in a rectangular box. A piston imparted strike-slip motion along a basal cut. In some experiments, uplifted areas underwent erosion. In others, all areas were subject to sedimentation. In experiments without erosion or sedimentation, first to develop were R-faults, at 16 to the basal cut. At later stages, P-faults and Y-faults took over. In section, faults splayed upward, forming flower structures. The splays had reverse components of slip. This was due to dilation, which reached 7% within fault splays. In experiments with erosion but no sedimentation, faults were less steep and accumulated greater amounts of reverse slip. In experiments with erosion and sedimentation, some faults propagated through their syn-kinematic cover, others became buried and inactive, whilst yet others were exposed by erosion. Therefore the average fault dip increased significantly. In experiments with sedimentation but no erosion, early faults propagated, whereas others became buried. Flower structures in nature have similar features. In areas of sedimentation, fault splays with gentle dips die out at depth, whereas steeper faults penetrate higher. In areas of erosion, strike-slip systems exhibit large amounts of reverse slip on steep bounding faults.

  20. Overprinted strike-slip deformation in the southern Valley and Ridge in Pennsylvania

    NASA Astrophysics Data System (ADS)

    Nickelsen, Richard P.

    2009-09-01

    Two major faults, over 32 km long and 6.4 km apart, truncate or overprint most previous folds and faults as they trend more northerly than the previous N25E to N40E fold trends. The faults were imposed as the last event in a region undergoing sequential counter-clockwise generation of tectonic structures. The western Big Cove anticline has an early NW verging thrust fault that emplaces resistant rocks on its NW limb. A 16 km overprint by the Cove Fault is manifested as 30 small northeast striking right-lateral strike-slip faults. This suggests major left-lateral strike-slip separation on the Cove Fault, but steep, dip-slip separation also occurs. From south to north the Cove Fault passes from SE dipping beds within the Big Cove anticline, to the vertical beds of the NW limb. Then it crosses four extended, separated, Tuscarora blocks along the ridge, brings Cambro-Ordovician carbonates against Devonian beds, and initiates the zone of overprinted right-lateral faults. Finally, it deflects the Lat 40N fault zone as it crosses to the next major anticline to the northwest. To the east, the major Path Valley Fault rotates and overprints the earlier Carrick Valley thrust. The Path Valley Fault and Cove Fault may be Mesozoic in age, based upon fault fabrics and overprinting on the east-west Lat 40N faults.