WorldWideScience

Sample records for stacking inter-actions centroid-centroid

  1. Centroid crossing

    International Nuclear Information System (INIS)

    Swift, G.

    1990-01-01

    This paper presents an algorithm for finding peaks in data spectra. It is based on calculating a moving centroid across the spectrum and picking off the points between which the calculated centroid crosses the channel number. Interpolation can then yield a more precise peak location. This algorithm can be implemented very efficiently requiring about one addition, subtraction, multiplication, and division operation per data point. With integer data and a centroid window equal to a power of two (so that the division can be done with shifts), the algorithm is particularly suited to efficient machine language implementation. With suitable adjustments (involving only little overhead except at suspected peaks), it is possible to minimize either false peak location or missing good peaks. Extending the method to more dimensions is straightforward although interpolating is more difficult. The algorithm has been used on a variety of nuclear data spectra with great success

  2. A focal plane metrology system and PSF centroiding experiment

    Science.gov (United States)

    Li, Haitao; Li, Baoquan; Cao, Yang; Li, Ligang

    2016-10-01

    In this paper, we present an overview of a detector array equipment metrology testbed and a micro-pixel centroiding experiment currently under development at the National Space Science Center, Chinese Academy of Sciences. We discuss on-going development efforts aimed at calibrating the intra-/inter-pixel quantum efficiency and pixel positions for scientific grade CMOS detector, and review significant progress in achieving higher precision differential centroiding for pseudo star images in large area back-illuminated CMOS detector. Without calibration of pixel positions and intrapixel response, we have demonstrated that the standard deviation of differential centroiding is below 2.0e-3 pixels.

  3. The Centroid of a Lie Triple Algebra

    Directory of Open Access Journals (Sweden)

    Xiaohong Liu

    2013-01-01

    Full Text Available General results on the centroids of Lie triple algebras are developed. Centroids of the tensor product of a Lie triple algebra and a unitary commutative associative algebra are studied. Furthermore, the centroid of the tensor product of a simple Lie triple algebra and a polynomial ring is completely determined.

  4. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    International Nuclear Information System (INIS)

    Briggs, A.M.; Greig, A.M.; Wrigley, T.V.; Tully, E.A.; Adams, P.E.; Bennell, K.L.

    2007-01-01

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r 0.83). Correspondence between measures was moderate for the Cobb method (r 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  5. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, A.M.; Greig, A.M. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia); University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Victoria (Australia); Wrigley, T.V.; Tully, E.A.; Adams, P.E.; Bennell, K.L. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia)

    2007-08-15

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r = 0.83). Correspondence between measures was moderate for the Cobb method (r = 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  6. Centroid motion in periodically focused beams

    International Nuclear Information System (INIS)

    Moraes, J.S.; Pakter, R.; Rizzato, F.B.

    2005-01-01

    The role of the centroid dynamics in the transport of periodically focused particle beams is investigated. A Kapchinskij-Vladimirskij equilibrium distribution for an off-axis beam is derived. It is shown that centroid and envelope dynamics are uncoupled and that unstable regions for the centroid dynamics overlap with previously stable regions for the envelope dynamics alone. Multiparticle simulations validate the findings. The effects of a conducting pipe encapsulating the beam are also investigated. It is shown that the charge induced at the pipe may generate chaotic orbits which can be detrimental to the adequate functioning of the transport mechanism

  7. Centroid finding method for position-sensitive detectors

    International Nuclear Information System (INIS)

    Radeka, V.; Boie, R.A.

    1979-10-01

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips of wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N/sup 3/2/, where N is the number of subdivisions

  8. Centroid finding method for position-sensitive detectors

    International Nuclear Information System (INIS)

    Radeka, V.; Boie, R.A.

    1980-01-01

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips or wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N 3 sup(/) 2 , where N is the number of subdivisions. (orig.)

  9. A general centroid determination methodology, with application to multilayer dielectric structures and thermally stimulated current measurements

    International Nuclear Information System (INIS)

    Miller, S.L.; Fleetwood, D.M.; McWhorter, P.J.; Reber, R.A. Jr.; Murray, J.R.

    1993-01-01

    A general methodology is developed to experimentally characterize the spatial distribution of occupied traps in dielectric films on a semiconductor. The effects of parasitics such as leakage, charge transport through more than one interface, and interface trap charge are quantitatively addressed. Charge transport with contributions from multiple charge species is rigorously treated. The methodology is independent of the charge transport mechanism(s), and is directly applicable to multilayer dielectric structures. The centroid capacitance, rather than the centroid itself, is introduced as the fundamental quantity that permits the generic analysis of multilayer structures. In particular, the form of many equations describing stacked dielectric structures becomes independent of the number of layers comprising the stack if they are expressed in terms of the centroid capacitance and/or the flatband voltage. The experimental methodology is illustrated with an application using thermally stimulated current (TSC) measurements. The centroid of changes (via thermal emission) in the amount of trapped charge was determined for two different samples of a triple-layer dielectric structure. A direct consequence of the TSC analyses is the rigorous proof that changes in interface trap charge can contribute, though typically not significantly, to thermally stimulated current

  10. Star point centroid algorithm based on background forecast

    Science.gov (United States)

    Wang, Jin; Zhao, Rujin; Zhu, Nan

    2014-09-01

    The calculation of star point centroid is a key step of improving star tracker measuring error. A star map photoed by APS detector includes several noises which have a great impact on veracity of calculation of star point centroid. Through analysis of characteristic of star map noise, an algorithm of calculation of star point centroid based on background forecast is presented in this paper. The experiment proves the validity of the algorithm. Comparing with classic algorithm, this algorithm not only improves veracity of calculation of star point centroid, but also does not need calibration data memory. This algorithm is applied successfully in a certain star tracker.

  11. Networks and centroid metrics for understanding football

    African Journals Online (AJOL)

    Gonçalo Dias

    games. However, it seems that the centroid metric, supported only by the position of players in the field ...... the strategy adopted by the coach (Gama et al., 2014). ... centroid distance as measures of team's tactical performance in youth football.

  12. Transverse centroid oscillations in solenoidially focused beam transport lattices

    International Nuclear Information System (INIS)

    Lund, Steven M.; Wootton, Christopher J.; Lee, Edward P.

    2009-01-01

    Transverse centroid oscillations are analyzed for a beam in a solenoid transport lattice. Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable 'alignment functions' and 'bending functions' that efficiently describe the characteristics of the centroid oscillations induced by both mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on the properties of the ideal lattice in the absence of errors and steering, and have associated expansion amplitudes set by the misalignments and steering fields, respectively. Applications of this formulation are presented for statistical analysis of centroid oscillations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.

  13. Bayesian centroid estimation for motif discovery.

    Science.gov (United States)

    Carvalho, Luis

    2013-01-01

    Biological sequences may contain patterns that signal important biomolecular functions; a classical example is regulation of gene expression by transcription factors that bind to specific patterns in genomic promoter regions. In motif discovery we are given a set of sequences that share a common motif and aim to identify not only the motif composition, but also the binding sites in each sequence of the set. We propose a new centroid estimator that arises from a refined and meaningful loss function for binding site inference. We discuss the main advantages of centroid estimation for motif discovery, including computational convenience, and how its principled derivation offers further insights about the posterior distribution of binding site configurations. We also illustrate, using simulated and real datasets, that the centroid estimator can differ from the traditional maximum a posteriori or maximum likelihood estimators.

  14. Bayesian centroid estimation for motif discovery.

    Directory of Open Access Journals (Sweden)

    Luis Carvalho

    Full Text Available Biological sequences may contain patterns that signal important biomolecular functions; a classical example is regulation of gene expression by transcription factors that bind to specific patterns in genomic promoter regions. In motif discovery we are given a set of sequences that share a common motif and aim to identify not only the motif composition, but also the binding sites in each sequence of the set. We propose a new centroid estimator that arises from a refined and meaningful loss function for binding site inference. We discuss the main advantages of centroid estimation for motif discovery, including computational convenience, and how its principled derivation offers further insights about the posterior distribution of binding site configurations. We also illustrate, using simulated and real datasets, that the centroid estimator can differ from the traditional maximum a posteriori or maximum likelihood estimators.

  15. Networks and centroid metrics for understanding football | Gama ...

    African Journals Online (AJOL)

    This study aimedto verifythe network of contacts resulting from the collective behaviour of professional football teams through the centroid method and networks as well, therebyproviding detailed information about the match to coaches and sport analysts. For this purpose, 999 collective attacking actions from twoteams were ...

  16. Hybridized centroid technique for 3D Molodensky-Badekas ...

    African Journals Online (AJOL)

    In view of this, the present study developed and tested two new hybrid centroid techniques known as the harmonic-quadratic mean and arithmetic-quadratic mean centroids. The proposed hybrid approaches were compared with the geometric mean, harmonic mean, median, quadratic mean and arithmetic mean. In addition ...

  17. Optimisation of centroiding algorithms for photon event counting imaging

    International Nuclear Information System (INIS)

    Suhling, K.; Airey, R.W.; Morgan, B.L.

    1999-01-01

    Approaches to photon event counting imaging in which the output events of an image intensifier are located using a centroiding technique have long been plagued by fixed pattern noise in which a grid of dimensions similar to those of the CCD pixels is superimposed on the image. This is caused by a mismatch between the photon event shape and the centroiding algorithm. We have used hyperbolic cosine, Gaussian, Lorentzian, parabolic as well as 3-, 5-, and 7-point centre of gravity algorithms, and hybrids thereof, to assess means of minimising this fixed pattern noise. We show that fixed pattern noise generated by the widely used centre of gravity centroiding is due to intrinsic features of the algorithm. Our results confirm that the recently proposed use of Gaussian centroiding does indeed show a significant reduction of fixed pattern noise compared to centre of gravity centroiding (Michel et al., Mon. Not. R. Astron. Soc. 292 (1997) 611-620). However, the disadvantage of a Gaussian algorithm is a centroiding failure for small pulses, caused by a division by zero, which leads to a loss of detective quantum efficiency (DQE) and to small amounts of residual fixed pattern noise. Using both real data from an image intensifier system employing a progressive scan camera, framegrabber and PC, and also synthetic data from Monte-Carlo simulations, we find that hybrid centroiding algorithms can reduce the fixed pattern noise without loss of resolution or loss of DQE. Imaging a test pattern to assess the features of the different algorithms shows that a hybrid of Gaussian and 3-point centre of gravity centroiding algorithms results in an optimum combination of low fixed pattern noise (lower than a simple Gaussian), high DQE, and high resolution. The Lorentzian algorithm gives the worst results in terms of high fixed pattern noise and low resolution, and the Gaussian and hyperbolic cosine algorithms have the lowest DQEs

  18. Empirical Centroid Fictitious Play: An Approach For Distributed Learning In Multi-Agent Games

    OpenAIRE

    Swenson, Brian; Kar, Soummya; Xavier, Joao

    2013-01-01

    The paper is concerned with distributed learning in large-scale games. The well-known fictitious play (FP) algorithm is addressed, which, despite theoretical convergence results, might be impractical to implement in large-scale settings due to intense computation and communication requirements. An adaptation of the FP algorithm, designated as the empirical centroid fictitious play (ECFP), is presented. In ECFP players respond to the centroid of all players' actions rather than track and respo...

  19. A Hybridized Centroid Technique for 3D Molodensky-Badekas ...

    African Journals Online (AJOL)

    Richannan

    the same point in a second reference frame (Ghilani, 2010). ... widely used approach by most researchers to compute values of centroid coordinates in the ... choice of centroid method on the Veis model has been investigated by Ziggah et al.

  20. Noise in position measurement by centroid calculation

    International Nuclear Information System (INIS)

    Volkov, P.

    1996-01-01

    The position of a particle trajectory in a gaseous (or semiconductor) detector can be measured by calculating the centroid of the induced charge on the cathode plane. The charge amplifiers attached to each cathode strip introduce noise which is added to the signal. This noise broadens the position resolution line. Our article gives an analytical tool to estimate the resolution broadening due to the noise per strip and the number of strips involved in the centroid calculation. It is shown that the position resolution increases faster than the square root of the number of strips involved. We also consider the consequence of added interstrip capacitors, intended to diminish the differential nonlinearity. It is shown that the position error increases slower than linearly with the interstrip capacities, due to the cancellation of correlated noise. The estimation we give, can be applied to calculations of position broadening other than the centroid finding. (orig.)

  1. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-01-01

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  2. Comparison of performance of some common Hartmann-Shack centroid estimation methods

    Science.gov (United States)

    Thatiparthi, C.; Ommani, A.; Burman, R.; Thapa, D.; Hutchings, N.; Lakshminarayanan, V.

    2016-03-01

    The accuracy of the estimation of optical aberrations by measuring the distorted wave front using a Hartmann-Shack wave front sensor (HSWS) is mainly dependent upon the measurement accuracy of the centroid of the focal spot. The most commonly used methods for centroid estimation such as the brightest spot centroid; first moment centroid; weighted center of gravity and intensity weighted center of gravity, are generally applied on the entire individual sub-apertures of the lens let array. However, these processes of centroid estimation are sensitive to the influence of reflections, scattered light, and noise; especially in the case where the signal spot area is smaller compared to the whole sub-aperture area. In this paper, we give a comparison of performance of the commonly used centroiding methods on estimation of optical aberrations, with and without the use of some pre-processing steps (thresholding, Gaussian smoothing and adaptive windowing). As an example we use the aberrations of the human eye model. This is done using the raw data collected from a custom made ophthalmic aberrometer and a model eye to emulate myopic and hyper-metropic defocus values up to 2 Diopters. We show that the use of any simple centroiding algorithm is sufficient in the case of ophthalmic applications for estimating aberrations within the typical clinically acceptable limits of a quarter Diopter margins, when certain pre-processing steps to reduce the impact of external factors are used.

  3. Statistical analysis of x-ray stress measurement by centroid method

    International Nuclear Information System (INIS)

    Kurita, Masanori; Amano, Jun; Sakamoto, Isao

    1982-01-01

    The X-ray technique allows a nondestructive and rapid measurement of residual stresses in metallic materials. The centroid method has an advantage over other X-ray methods in that it can determine the angular position of a diffraction line, from which the stress is calculated, even with an asymmetrical line profile. An equation for the standard deviation of the angular position of a diffraction line, σsub(p), caused by statistical fluctuation was derived, which is a fundamental source of scatter in X-ray stress measurements. This equation shows that an increase of X-ray counts by a factor of k results in a decrease of σsub(p) by a factor of 1/√k. It also shows that σsub(p) increases rapidly as the angular range used in calculating the centroid increases. It is therefore important to calculate the centroid using the narrow angular range between the two ends of the diffraction line where it starts to deviate from the straight background line. By using quenched structural steels JIS S35C and S45C, the residual stresses and their standard deviations were calculated by the centroid, parabola, Gaussian curve, and half-width methods, and the results were compared. The centroid of a diffraction line was affected greatly by the background line used. The standard deviation of the stress measured by the centroid method was found to be the largest among the four methods. (author)

  4. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2010-01-01

    A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity ( 14 Wcm -2 ) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

  5. Centroids of effective interactions from measured single-particle energies: An application

    International Nuclear Information System (INIS)

    Cole, B.J.

    1990-01-01

    Centroids of the effective nucleon-nucleon interaction for the mass region A=28--64 are extracted directly from experimental single-particle spectra, by comparing single-particle energies relative to different cores. Uncertainties in the centroids are estimated at approximately 100 keV, except in cases of exceptional fragmentation of the single-particle strength. The use of a large number of inert cores allows the dependence of the interaction on mass or model space to be investigated. The method permits accurate empirical modifications to be made to realistic interactions calculated from bare nucleon-nucleon potentials, which are known to possess defective centroids in many cases. In addition, the centroids can be used as input to the more sophisticated fitting procedures that are employed to produce matrix elements of the effective interaction

  6. A quantum generalization of intrinsic reaction coordinate using path integral centroid coordinates

    International Nuclear Information System (INIS)

    Shiga, Motoyuki; Fujisaki, Hiroshi

    2012-01-01

    We propose a generalization of the intrinsic reaction coordinate (IRC) for quantum many-body systems described in terms of the mass-weighted ring polymer centroids in the imaginary-time path integral theory. This novel kind of reaction coordinate, which may be called the ''centroid IRC,'' corresponds to the minimum free energy path connecting reactant and product states with a least amount of reversible work applied to the center of masses of the quantum nuclei, i.e., the centroids. We provide a numerical procedure to obtain the centroid IRC based on first principles by combining ab initio path integral simulation with the string method. This approach is applied to NH 3 molecule and N 2 H 5 - ion as well as their deuterated isotopomers to study the importance of nuclear quantum effects in the intramolecular and intermolecular proton transfer reactions. We find that, in the intramolecular proton transfer (inversion) of NH 3 , the free energy barrier for the centroid variables decreases with an amount of about 20% compared to the classical one at the room temperature. In the intermolecular proton transfer of N 2 H 5 - , the centroid IRC is largely deviated from the ''classical'' IRC, and the free energy barrier is reduced by the quantum effects even more drastically.

  7. Implementation of the Centroid Method for the Correction of Turbulence

    Directory of Open Access Journals (Sweden)

    Enric Meinhardt-Llopis

    2014-07-01

    Full Text Available The centroid method for the correction of turbulence consists in computing the Karcher-Fréchet mean of the sequence of input images. The direction of deformation between a pair of images is determined by the optical flow. A distinguishing feature of the centroid method is that it can produce useful results from an arbitrarily small set of input images.

  8. Major shell centroids in the symplectic collective model

    International Nuclear Information System (INIS)

    Draayer, J.P.; Rosensteel, G.; Tulane Univ., New Orleans, LA

    1983-01-01

    Analytic expressions are given for the major shell centroids of the collective potential V(#betta#, #betta#) and the shape observable #betta# 2 in the Sp(3,R) symplectic model. The tools of statistical spectroscopy are shown to be useful, firstly, in translating a requirement that the underlying shell structure be preserved into constraints on the parameters of the collective potential and, secondly, in giving a reasonable estimate for a truncation of the infinite dimensional symplectic model space from experimental B(E2) transition strengths. Results based on the centroid information are shown to compare favorably with results from exact calculations in the case of 20 Ne. (orig.)

  9. Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation

    Directory of Open Access Journals (Sweden)

    Yicheng Jiang

    2014-01-01

    Full Text Available In geosynchronous Earth orbit SAR (GEO SAR, Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.

  10. The effect of event shape on centroiding in photon counting detectors

    International Nuclear Information System (INIS)

    Kawakami, Hajime; Bone, David; Fordham, John; Michel, Raul

    1994-01-01

    High resolution, CCD readout, photon counting detectors employ simple centroiding algorithms for defining the spatial position of each detected event. The accuracy of centroiding is very dependent upon a number of parameters including the profile, energy and width of the intensified event. In this paper, we provide an analysis of how the characteristics of an intensified event change as the input count rate increases and the consequent effect on centroiding. The changes in these parameters are applied in particular to the MIC photon counting detector developed at UCL for ground and space based astronomical applications. This detector has a maximum format of 3072x2304 pixels permitting its use in the highest resolution applications. Individual events, at light level from 5 to 1000k events/s over the detector area, were analysed. It was found that both the asymmetry and width of event profiles were strongly dependent upon the energy of the intensified event. The variation in profile then affected the centroiding accuracy leading to loss of resolution. These inaccuracies have been quantified for two different 3 CCD pixel centroiding algorithms and one 2 pixel algorithm. The results show that a maximum error of less than 0.05 CCD pixel occurs with the 3 pixel algorithms and 0.1 CCD pixel for the 2 pixel algorithm. An improvement is proposed by utilising straight pore MCPs in the intensifier and a 70 μm air gap in front of the CCD. ((orig.))

  11. Automatic centroid detection and surface measurement with a digital Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Zhao, Liping; Li, Xiang; Fang, Zhongping

    2010-01-01

    With the breakthrough of manufacturing technologies, the measurement of surface profiles is becoming a big issue. A Shack–Hartmann wavefront sensor (SHWS) provides a promising technology for non-contact surface measurement with a number of advantages over interferometry. The SHWS splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. So the accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented a new centroid measurement algorithm based on an adaptive thresholding and dynamic windowing method by utilizing image-processing techniques. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront and measure the 3D profile of the surface. The system has been tested with various simulated and real surfaces such as flat surfaces, spherical and aspherical surfaces as well as deformable surfaces. The experimental results demonstrate that the system has good accuracy, repeatability and immunity to optical misalignment. The system is also suitable for on-line applications of surface measurement

  12. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    International Nuclear Information System (INIS)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-01-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  13. Research on Centroid Position for Stairs Climbing Stability of Search and Rescue Robot

    Directory of Open Access Journals (Sweden)

    Yan Guo

    2011-01-01

    Full Text Available This paper represents the relationship between the stability of stairs climbing and the centroid position of the search and rescue robot. The robot system is considered as a mass point-plane model and the kinematics features are analyzed to find the relationship between centroid position and the maximal pitch angle of stairs the robot could climb up. A computable function about this relationship is given in this paper. During the stairs climbing, there is a maximal stability-keeping angle depends on the centroid position and the pitch angle of stairs, and the numerical formula is developed about the relationship between the maximal stability-keeping angle and the centroid position and pitch angle of stairs. The experiment demonstrates the trustworthy and correction of the method in the paper.

  14. Intraoperative cyclorotation and pupil centroid shift during LASIK and PRK.

    Science.gov (United States)

    Narváez, Julio; Brucks, Matthew; Zimmerman, Grenith; Bekendam, Peter; Bacon, Gregory; Schmid, Kristin

    2012-05-01

    To determine the degree of cyclorotation and centroid shift in the x and y axis that occurs intraoperatively during LASIK and photorefractive keratectomy (PRK). Intraoperative cyclorotation and centroid shift were measured in 63 eyes from 34 patients with a mean age of 34 years (range: 20 to 56 years) undergoing either LASIK or PRK. Preoperatively, an iris image of each eye was obtained with the VISX WaveScan Wavefront System (Abbott Medical Optics Inc) with iris registration. A VISX Star S4 (Abbott Medical Optics Inc) laser was later used to measure cyclotorsion and pupil centroid shift at the beginning of the refractive procedure and after flap creation or epithelial removal. The mean change in intraoperative cyclorotation was 1.48±1.11° in LASIK eyes and 2.02±2.63° in PRK eyes. Cyclorotation direction changed by >2° in 21% of eyes after flap creation in LASIK and in 32% of eyes after epithelial removal in PRK. The respective mean intraoperative shift in the x axis and y axis was 0.13±0.15 mm and 0.17±0.14 mm, respectively, in LASIK eyes, and 0.09±0.07 mm and 0.10±0.13 mm, respectively, in PRK eyes. Intraoperative centroid shifts >100 μm in either the x axis or y axis occurred in 71% of LASIK eyes and 55% of PRK eyes. Significant changes in cyclotorsion and centroid shifts were noted prior to surgery as well as intraoperatively with both LASIK and PRK. It may be advantageous to engage iris registration immediately prior to ablation to provide a reference point representative of eye position at the initiation of laser delivery. Copyright 2012, SLACK Incorporated.

  15. Centroid vetting of transiting planet candidates from the Next Generation Transit Survey

    Science.gov (United States)

    Günther, Maximilian N.; Queloz, Didier; Gillen, Edward; McCormac, James; Bayliss, Daniel; Bouchy, Francois; Walker, Simon. R.; West, Richard G.; Eigmüller, Philipp; Smith, Alexis M. S.; Armstrong, David J.; Burleigh, Matthew; Casewell, Sarah L.; Chaushev, Alexander P.; Goad, Michael R.; Grange, Andrew; Jackman, James; Jenkins, James S.; Louden, Tom; Moyano, Maximiliano; Pollacco, Don; Poppenhaeger, Katja; Rauer, Heike; Raynard, Liam; Thompson, Andrew P. G.; Udry, Stéphane; Watson, Christopher A.; Wheatley, Peter J.

    2017-11-01

    The Next Generation Transit Survey (NGTS), operating in Paranal since 2016, is a wide-field survey to detect Neptunes and super-Earths transiting bright stars, which are suitable for precise radial velocity follow-up and characterization. Thereby, its sub-mmag photometric precision and ability to identify false positives are crucial. Particularly, variable background objects blended in the photometric aperture frequently mimic Neptune-sized transits and are costly in follow-up time. These objects can best be identified with the centroiding technique: if the photometric flux is lost off-centre during an eclipse, the flux centroid shifts towards the centre of the target star. Although this method has successfully been employed by the Kepler mission, it has previously not been implemented from the ground. We present a fully automated centroid vetting algorithm developed for NGTS, enabled by our high-precision autoguiding. Our method allows detecting centroid shifts with an average precision of 0.75 milli-pixel (mpix), and down to 0.25 mpix for specific targets, for a pixel size of 4.97 arcsec. The algorithm is now part of the NGTS candidate vetting pipeline and automatically employed for all detected signals. Further, we develop a joint Bayesian fitting model for all photometric and centroid data, allowing to disentangle which object (target or background) is causing the signal, and what its astrophysical parameters are. We demonstrate our method on two NGTS objects of interest. These achievements make NGTS the first ground-based wide-field transit survey ever to successfully apply the centroiding technique for automated candidate vetting, enabling the production of a robust candidate list before follow-up.

  16. Combined centroid-envelope dynamics of intense, magnetically focused charged beams surrounded by conducting walls

    International Nuclear Information System (INIS)

    Fiuza, K.; Rizzato, F.B.; Pakter, R.

    2006-01-01

    In this paper we analyze the combined envelope-centroid dynamics of magnetically focused high-intensity charged beams surrounded by conducting walls. Similar to the case where conducting walls are absent, it is shown that the envelope and centroid dynamics decouple from each other. Mismatched envelopes still decay into equilibrium with simultaneous emittance growth, but the centroid keeps oscillating with no appreciable energy loss. Some estimates are performed to analytically obtain characteristics of halo formation seen in the full simulations

  17. Adaptive thresholding and dynamic windowing method for automatic centroid detection of digital Shack-Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin Xiaoming; Li Xiang; Zhao Liping; Fang Zhongping

    2009-01-01

    A Shack-Hartmann wavefront sensor (SWHS) splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. The accuracy of the centroid measurement determines the accuracy of the SWHS. Many methods have been presented to improve the accuracy of the wavefront centroid measurement. However, most of these methods are discussed from the point of view of optics, based on the assumption that the spot intensity of the SHWS has a Gaussian distribution, which is not applicable to the digital SHWS. In this paper, we present a centroid measurement algorithm based on the adaptive thresholding and dynamic windowing method by utilizing image processing techniques for practical application of the digital SHWS in surface profile measurement. The method can detect the centroid of each focal spot precisely and robustly by eliminating the influence of various noises, such as diffraction of the digital SHWS, unevenness and instability of the light source, as well as deviation between the centroid of the focal spot and the center of the detection area. The experimental results demonstrate that the algorithm has better precision, repeatability, and stability compared with other commonly used centroid methods, such as the statistical averaging, thresholding, and windowing algorithms.

  18. Ambiguity Of Doppler Centroid In Synthetic-Aperture Radar

    Science.gov (United States)

    Chang, Chi-Yung; Curlander, John C.

    1991-01-01

    Paper discusses performances of two algorithms for resolution of ambiguity in estimated Doppler centroid frequency of echoes in synthetic-aperture radar. One based on range-cross-correlation technique, other based on multiple-pulse-repetition-frequency technique.

  19. Finger vein identification using fuzzy-based k-nearest centroid neighbor classifier

    Science.gov (United States)

    Rosdi, Bakhtiar Affendi; Jaafar, Haryati; Ramli, Dzati Athiar

    2015-02-01

    In this paper, a new approach for personal identification using finger vein image is presented. Finger vein is an emerging type of biometrics that attracts attention of researchers in biometrics area. As compared to other biometric traits such as face, fingerprint and iris, finger vein is more secured and hard to counterfeit since the features are inside the human body. So far, most of the researchers focus on how to extract robust features from the captured vein images. Not much research was conducted on the classification of the extracted features. In this paper, a new classifier called fuzzy-based k-nearest centroid neighbor (FkNCN) is applied to classify the finger vein image. The proposed FkNCN employs a surrounding rule to obtain the k-nearest centroid neighbors based on the spatial distributions of the training images and their distance to the test image. Then, the fuzzy membership function is utilized to assign the test image to the class which is frequently represented by the k-nearest centroid neighbors. Experimental evaluation using our own database which was collected from 492 fingers shows that the proposed FkNCN has better performance than the k-nearest neighbor, k-nearest-centroid neighbor and fuzzy-based-k-nearest neighbor classifiers. This shows that the proposed classifier is able to identify the finger vein image effectively.

  20. The efficiency of the centroid method compared to a simple average

    DEFF Research Database (Denmark)

    Eskildsen, Jacob Kjær; Kristensen, Kai; Nielsen, Rikke

    Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot.......Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot....

  1. Formulation of state projected centroid molecular dynamics: Microcanonical ensemble and connection to the Wigner distribution.

    Science.gov (United States)

    Orr, Lindsay; Hernández de la Peña, Lisandro; Roy, Pierre-Nicholas

    2017-06-07

    A derivation of quantum statistical mechanics based on the concept of a Feynman path centroid is presented for the case of generalized density operators using the projected density operator formalism of Blinov and Roy [J. Chem. Phys. 115, 7822-7831 (2001)]. The resulting centroid densities, centroid symbols, and centroid correlation functions are formulated and analyzed in the context of the canonical equilibrium picture of Jang and Voth [J. Chem. Phys. 111, 2357-2370 (1999)]. The case where the density operator projects onto a particular energy eigenstate of the system is discussed, and it is shown that one can extract microcanonical dynamical information from double Kubo transformed correlation functions. It is also shown that the proposed projection operator approach can be used to formally connect the centroid and Wigner phase-space distributions in the zero reciprocal temperature β limit. A Centroid Molecular Dynamics (CMD) approximation to the state-projected exact quantum dynamics is proposed and proven to be exact in the harmonic limit. The state projected CMD method is also tested numerically for a quartic oscillator and a double-well potential and found to be more accurate than canonical CMD. In the case of a ground state projection, this method can resolve tunnelling splittings of the double well problem in the higher barrier regime where canonical CMD fails. Finally, the state-projected CMD framework is cast in a path integral form.

  2. Formulation of state projected centroid molecular dynamics: Microcanonical ensemble and connection to the Wigner distribution

    Science.gov (United States)

    Orr, Lindsay; Hernández de la Peña, Lisandro; Roy, Pierre-Nicholas

    2017-06-01

    A derivation of quantum statistical mechanics based on the concept of a Feynman path centroid is presented for the case of generalized density operators using the projected density operator formalism of Blinov and Roy [J. Chem. Phys. 115, 7822-7831 (2001)]. The resulting centroid densities, centroid symbols, and centroid correlation functions are formulated and analyzed in the context of the canonical equilibrium picture of Jang and Voth [J. Chem. Phys. 111, 2357-2370 (1999)]. The case where the density operator projects onto a particular energy eigenstate of the system is discussed, and it is shown that one can extract microcanonical dynamical information from double Kubo transformed correlation functions. It is also shown that the proposed projection operator approach can be used to formally connect the centroid and Wigner phase-space distributions in the zero reciprocal temperature β limit. A Centroid Molecular Dynamics (CMD) approximation to the state-projected exact quantum dynamics is proposed and proven to be exact in the harmonic limit. The state projected CMD method is also tested numerically for a quartic oscillator and a double-well potential and found to be more accurate than canonical CMD. In the case of a ground state projection, this method can resolve tunnelling splittings of the double well problem in the higher barrier regime where canonical CMD fails. Finally, the state-projected CMD framework is cast in a path integral form.

  3. Optimizing the calculation of point source count-centroid in pixel size measurement

    International Nuclear Information System (INIS)

    Zhou Luyi; Kuang Anren; Su Xianyu

    2004-01-01

    Purpose: Pixel size is an important parameter of gamma camera and SPECT. A number of Methods are used for its accurate measurement. In the original count-centroid method, where the image of a point source(PS) is acquired and its count-centroid calculated to represent PS position in the image, background counts are inevitable. Thus the measured count-centroid (Xm) is an approximation of the true count-centroid (Xp) of the PS, i.e. Xm=Xp+(Xb-Xp)/(1+Rp/Rb), where Rp is the net counting rate of the PS, Xb the background count-centroid and Rb the background counting rate. To get accurate measurement, Rp must be very big, which is unpractical, resulting in the variation of measured pixel size. Rp-independent calculation of PS count-centroid is desired. Methods: The proposed method attempted to eliminate the effect of the term (Xb-Xp)/(1+Rp/Rb) by bringing Xb closer to Xp and by reducing Rb. In the acquired PS image, a circular ROI was generated to enclose the PS, the pixel with the maximum count being the center of the ROI. To choose the diameter (D) of the ROI, a Gaussian count distribution was assumed for the PS, accordingly, K=I-(0.5)D/R percent of the total PS counts was in the ROI, R being the full width at half maximum of the PS count distribution. D was set to be 6*R to enclose most (K=98.4%) of the PS counts. The count-centroid of the ROI was calculated to represent Xp. The proposed method was tested in measuring the pixel size of a well-tuned SPECT, whose pixel size was estimated to be 3.02 mm according to its mechanical and electronic setting (128*128 matrix, 387 mm UFOV, ZOOM=1). For comparison, the original method, which was use in the former versions of some commercial SPECT software, was also tested. 12 PSs were prepared and their image acquired and stored. The net counting rate of the PSs increased from 10cps to 1183cps. Results: Using the proposed method, the measured pixel size (in mm) varied only between 3.00 and 3.01( mean= 3.01±0.00) as Rp increased

  4. Automatic extraction of nuclei centroids of mouse embryonic cells from fluorescence microscopy images.

    Directory of Open Access Journals (Sweden)

    Md Khayrul Bashar

    Full Text Available Accurate identification of cell nuclei and their tracking using three dimensional (3D microscopic images is a demanding task in many biological studies. Manual identification of nuclei centroids from images is an error-prone task, sometimes impossible to accomplish due to low contrast and the presence of noise. Nonetheless, only a few methods are available for 3D bioimaging applications, which sharply contrast with 2D analysis, where many methods already exist. In addition, most methods essentially adopt segmentation for which a reliable solution is still unknown, especially for 3D bio-images having juxtaposed cells. In this work, we propose a new method that can directly extract nuclei centroids from fluorescence microscopy images. This method involves three steps: (i Pre-processing, (ii Local enhancement, and (iii Centroid extraction. The first step includes two variations: first variation (Variant-1 uses the whole 3D pre-processed image, whereas the second one (Variant-2 modifies the preprocessed image to the candidate regions or the candidate hybrid image for further processing. At the second step, a multiscale cube filtering is employed in order to locally enhance the pre-processed image. Centroid extraction in the third step consists of three stages. In Stage-1, we compute a local characteristic ratio at every voxel and extract local maxima regions as candidate centroids using a ratio threshold. Stage-2 processing removes spurious centroids from Stage-1 results by analyzing shapes of intensity profiles from the enhanced image. An iterative procedure based on the nearest neighborhood principle is then proposed to combine if there are fragmented nuclei. Both qualitative and quantitative analyses on a set of 100 images of 3D mouse embryo are performed. Investigations reveal a promising achievement of the technique presented in terms of average sensitivity and precision (i.e., 88.04% and 91.30% for Variant-1; 86.19% and 95.00% for Variant-2

  5. A variational centroid density procedure for the calculation of transmission coefficients for asymmetric barriers at low temperature

    International Nuclear Information System (INIS)

    Messina, M.; Schenter, G.K.; Garrett, B.C.

    1995-01-01

    The low temperature behavior of the centroid density method of Voth, Chandler, and Miller (VCM) [J. Chem. Phys. 91, 7749 (1989)] is investigated for tunneling through a one-dimensional barrier. We find that the bottleneck for a quantum activated process as defined by VCM does not correspond to the classical bottleneck for the case of an asymmetric barrier. If the centroid density is constrained to be at the classical bottleneck for an asymmetric barrier, the centroid density method can give transmission coefficients that are too large by as much as five orders of magnitude. We follow a variational procedure, as suggested by VCM, whereby the best transmission coefficient is found by varying the position of the centroid until the minimum value for this transmission coefficient is obtained. This is a procedure that is readily generalizable to multidimensional systems. We present calculations on several test systems which show that this variational procedure greatly enhances the accuracy of the centroid density method compared to when the centroid is constrained to be at the barrier top. Furthermore, the relation of this procedure to the low temperature periodic orbit or ''instanton'' approach is discussed. copyright 1995 American Institute of Physics

  6. Robustness of regularities for energy centroids in the presence of random interactions

    International Nuclear Information System (INIS)

    Zhao, Y.M.; Arima, A.; Yoshida, N.; Ogawa, K.; Yoshinaga, N.; Kota, V. K. B.

    2005-01-01

    In this paper we study energy centroids such as those with fixed spin and isospin and those with fixed irreducible representations for both bosons and fermions, in the presence of random two-body and/or three-body interactions. Our results show that regularities of energy centroids of fixed-spin states reported in earlier works are very robust in these more complicated cases. We suggest that these behaviors might be intrinsic features of quantum many-body systems interacting by random forces

  7. Optimizing the calculation of point source count-centroid in pixel size measurement

    International Nuclear Information System (INIS)

    Zhou Luyi; Kuang Anren; Su Xianyu

    2004-01-01

    Pixel size is an important parameter of gamma camera and SPECT. A number of methods are used for its accurate measurement. In the original count-centroid method, where the image of a point source (PS) is acquired and its count-centroid calculated to represent PS position in the image, background counts are inevitable. Thus the measured count-centroid (X m ) is an approximation of the true count-centroid (X p ) of the PS, i.e. X m =X p + (X b -X p )/(1+R p /R b ), where Rp is the net counting rate of the PS, X b the background count-centroid and Rb the background counting. To get accurate measurement, R p must be very big, which is unpractical, resulting in the variation of measured pixel size. R p -independent calculation of PS count-centroid is desired. Methods: The proposed method attempted to eliminate the effect of the term (X b -X p )/(1 + R p /R b ) by bringing X b closer to X p and by reducing R b . In the acquired PS image, a circular ROI was generated to enclose the PS, the pixel with the maximum count being the center of the ROI. To choose the diameter (D) of the ROI, a Gaussian count distribution was assumed for the PS, accordingly, K=1-(0.5) D/R percent of the total PS counts was in the ROI, R being the full width at half maximum of the PS count distribution. D was set to be 6*R to enclose most (K=98.4%) of the PS counts. The count-centroid of the ROI was calculated to represent X p . The proposed method was tested in measuring the pixel size of a well-tuned SPECT, whose pixel size was estimated to be 3.02 mm according to its mechanical and electronic setting (128 x 128 matrix, 387 mm UFOV, ZOOM=1). For comparison, the original method, which was use in the former versions of some commercial SPECT software, was also tested. 12 PSs were prepared and their image acquired and stored. The net counting rate of the PSs increased from 10 cps to 1183 cps. Results: Using the proposed method, the measured pixel size (in mm) varied only between 3.00 and 3.01 (mean

  8. 1,3-Bis(chloro-meth-yl)-2-methyl-5-nitro-benzene.

    Science.gov (United States)

    Shao, Chang-Lun; Li, Chunyuan; Liu, Zhen; Wei, Mei-Yan; Wang, Chang-Yun

    2008-03-20

    The title compound, C(9)H(9)Cl(2)NO(2), is a natural product isolated from the endophytic fungus No. B77 of the mangrove tree from the South China Sea coast. In the crystal structure, the mol-ecules lie on twofold axes and form offset stacks through face-to-face π-π inter-actions. Adjacent mol-ecules in each stack are related by a centre of inversion and have an inter-planar separation of 3.53 (1) Å, with a centroid-centroid distance of 3.76 (1) Å. Between stacks, there are C-H⋯O inter-actions to the nitro groups and Cl⋯Cl contacts of 3.462 (1) Å.

  9. Determination of star bodies from p-centroid bodies

    Indian Academy of Sciences (India)

    An immediate consequence of the definition of the p-centroid body of K is that for any .... The dual mixed volume ˜V−p(K, L) of star bodies K, L can be defined by d. −p ..... [16] Lindenstrauss J and Milman V D, Local theory of normed spaces and ...

  10. A further investigation of the centroid-to-centroid method for stereotactic lung radiotherapy: A phantom study

    International Nuclear Information System (INIS)

    Lu, Bo; Samant, Sanjiv; Mittauer, Kathryn; Lee, Soyoung; Huang, Yin; Li, Jonathan; Kahler, Darren; Liu, Chihray

    2013-01-01

    Purpose: Our previous study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] proposed a deformable-registration-based patient setup strategy called the centroid-to-centroid (CTC) method, which can perform an accurate alignment of internal-target-volume (ITV) centroids between averaged four-dimensional computed tomography and cone-beam computed tomography (CBCT) images. Scenarios with variations between CBCT and simulation CT caused by irregular breathing and/or tumor change were not specifically considered in the patient study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] due to the lack of both a sufficiently large patient data sample and a method of tumor tracking. The aim of this study is to thoroughly investigate and compare the impacts of breathing pattern and tumor change on both the CTC and the translation-only (T-only) gray-value mode strategies by employing a four-dimensional (4D) lung phantom.Methods: A sophisticated anthropomorphic 4D phantom (CIRS Dynamic Thorax Phantom model 008) was employed to simulate all desired respiratory variations. The variation scenarios were classified into four groups: inspiration to expiration ratio (IE ratio) change, tumor trajectory change, tumor position change, tumor size change, and the combination of these changes. For each category the authors designed several scenarios to demonstrate the effects of different levels of breathing variation on both of the T-only and the CTC methods. Each scenario utilized 4DCT and CBCT scans. The ITV centroid alignment discrepancies for CTC and T-only were evaluated. The dose-volume-histograms (DVHs) of ITVs for two extreme cases were analyzed.Results: Except for some extreme cases in the combined group, the accuracy of the CTC registration was about 2 mm for all cases for

  11. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming; Wonka, Peter

    2015-01-01

    We present a novel remeshing algorithm that avoids triangles with small and triangles with large (obtuse) angles. Our solution is based on an extension to Centroidal Voronoi Tesselation (CVT). We augment the original CVT formulation by a penalty term that penalizes short Voronoi edges, while the CVT term helps to avoid small angles. Our results show significant improvements of the remeshing quality over the state of the art.

  12. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming

    2015-12-03

    We present a novel remeshing algorithm that avoids triangles with small and triangles with large (obtuse) angles. Our solution is based on an extension to Centroidal Voronoi Tesselation (CVT). We augment the original CVT formulation by a penalty term that penalizes short Voronoi edges, while the CVT term helps to avoid small angles. Our results show significant improvements of the remeshing quality over the state of the art.

  13. Determination of star bodies from p-centroid bodies

    Indian Academy of Sciences (India)

    In this paper, we prove that an origin-symmetric star body is uniquely determined by its -centroid body. Furthermore, using spherical harmonics, we establish a result for non-symmetric star bodies. As an application, we show that there is a unique member of p ⟨ K ⟩ characterized by having larger volume than any other ...

  14. Systematic shifts of evaluated charge centroid for the cathode read-out multiwire proportional chamber

    International Nuclear Information System (INIS)

    Endo, I.; Kawamoto, T.; Mizuno, Y.; Ohsugi, T.; Taniguchi, T.; Takeshita, T.

    1981-01-01

    We have investigated the systematic error associtated with the charge centroid evaluation for the cathode read-out multiwire proportional chamber. Correction curves for the systematic error according to six centroid finding algorithms have been obtained by using the charge distribution calculated in a simple electrostatic mode. They have been experimentally examined and proved to be essential for the accurate determination of the irradiated position. (orig.)

  15. Uncertainty Quantification in Earthquake Source Characterization with Probabilistic Centroid Moment Tensor Inversion

    Science.gov (United States)

    Dettmer, J.; Benavente, R. F.; Cummins, P. R.

    2017-12-01

    This work considers probabilistic, non-linear centroid moment tensor inversion of data from earthquakes at teleseismic distances. The moment tensor is treated as deviatoric and centroid location is parametrized with fully unknown latitude, longitude, depth and time delay. The inverse problem is treated as fully non-linear in a Bayesian framework and the posterior density is estimated with interacting Markov chain Monte Carlo methods which are implemented in parallel and allow for chain interaction. The source mechanism and location, including uncertainties, are fully described by the posterior probability density and complex trade-offs between various metrics are studied. These include the percent of double couple component as well as fault orientation and the probabilistic results are compared to results from earthquake catalogs. Additional focus is on the analysis of complex events which are commonly not well described by a single point source. These events are studied by jointly inverting for multiple centroid moment tensor solutions. The optimal number of sources is estimated by the Bayesian information criterion to ensure parsimonious solutions. [Supported by NSERC.

  16. Fast centroid algorithm for determining the surface plasmon resonance angle using the fixed-boundary method

    International Nuclear Information System (INIS)

    Zhan, Shuyue; Wang, Xiaoping; Liu, Yuling

    2011-01-01

    To simplify the algorithm for determining the surface plasmon resonance (SPR) angle for special applications and development trends, a fast method for determining an SPR angle, called the fixed-boundary centroid algorithm, has been proposed. Two experiments were conducted to compare three centroid algorithms from the aspects of the operation time, sensitivity to shot noise, signal-to-noise ratio (SNR), resolution, and measurement range. Although the measurement range of this method was narrower, the other performance indices were all better than the other two centroid methods. This method has outstanding performance, high speed, good conformity, low error and a high SNR and resolution. It thus has the potential to be widely adopted

  17. Noninvasive measurement of cardiopulmonary blood volume: evaluation of the centroid method

    International Nuclear Information System (INIS)

    Fouad, F.M.; MacIntyre, W.J.; Tarazi, R.C.

    1981-01-01

    Cardiopulmonary blood volume (CPV) and mean pulmonary transit time (MTT) determined by radionuclide measurements (Tc-99m HSA) were compared with values obtained from simultaneous dye-dilution (DD) studies (indocyanine green). The mean transit time was obtained from radionuclide curves by two methods: the peak-to-peak time and the interval between the two centroids determined from the right and left-ventricular time-concentration curves. Correlation of dye-dilution MTT and peak-to-peak time was significant (r = 0.79, p < 0.001), but its correlation with centroid-derived values was better (r = 0.86, p < 0.001). CPV values (using the centroid method for radionuclide technique) correlated significantly with values derived from dye-dilution curves (r = 0.74, p < 0.001). Discrepancies between the two were greater the more rapid the circulation (r = 0.61, p < 0.01), suggesting that minor inaccuracies of dye-dilution methods, due to positioning or delay of the system, can become magnified in hyperkinetic conditions. The radionuclide method is simple, repeatable, and noninvasive, and it provides simultaneous evaluation of pulmonary and systemic hemodynamics. Further, calculation of the ratio of cardiopulmonary to total blood volume can be used as an index of overall venous distensibility and relocation of intravascular blood volume

  18. Doppler Centroid Estimation for Airborne SAR Supported by POS and DEM

    Directory of Open Access Journals (Sweden)

    CHENG Chunquan

    2015-05-01

    Full Text Available It is difficult to estimate the Doppler frequency and modulating rate for airborne SAR by using traditional vector method due to instable flight and complex terrain. In this paper, it is qualitatively analyzed that the impacts of POS, DEM and their errors on airborne SAR Doppler parameters. Then an innovative vector method is presented based on the range-coplanarity equation to estimate the Doppler centroid taking the POS and DEM as auxiliary data. The effectiveness of the proposed method is validated and analyzed via the simulation experiments. The theoretical analysis and experimental results show that the method can be used to estimate the Doppler centroid with high accuracy even in the cases of high relief, instable flight, and large squint SAR.

  19. Performance Analysis of Combined Methods of Genetic Algorithm and K-Means Clustering in Determining the Value of Centroid

    Science.gov (United States)

    Adya Zizwan, Putra; Zarlis, Muhammad; Budhiarti Nababan, Erna

    2017-12-01

    The determination of Centroid on K-Means Algorithm directly affects the quality of the clustering results. Determination of centroid by using random numbers has many weaknesses. The GenClust algorithm that combines the use of Genetic Algorithms and K-Means uses a genetic algorithm to determine the centroid of each cluster. The use of the GenClust algorithm uses 50% chromosomes obtained through deterministic calculations and 50% is obtained from the generation of random numbers. This study will modify the use of the GenClust algorithm in which the chromosomes used are 100% obtained through deterministic calculations. The results of this study resulted in performance comparisons expressed in Mean Square Error influenced by centroid determination on K-Means method by using GenClust method, modified GenClust method and also classic K-Means.

  20. Multiple centroid method to evaluate the adaptability of alfalfa genotypes

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2015-02-01

    Full Text Available This study aimed to evaluate the efficiency of multiple centroids to study the adaptability of alfalfa genotypes (Medicago sativa L.. In this method, the genotypes are compared with ideotypes defined by the bissegmented regression model, according to the researcher's interest. Thus, genotype classification is carried out as determined by the objective of the researcher and the proposed recommendation strategy. Despite the great potential of the method, it needs to be evaluated under the biological context (with real data. In this context, we used data on the evaluation of dry matter production of 92 alfalfa cultivars, with 20 cuttings, from an experiment in randomized blocks with two repetitions carried out from November 2004 to June 2006. The multiple centroid method proved efficient for classifying alfalfa genotypes. Moreover, it showed no unambiguous indications and provided that ideotypes were defined according to the researcher's interest, facilitating data interpretation.

  1. Establishing the soft and hard tissue area centers (centroids) for the skull and introducing a newnon-anatomical cephalometric line

    International Nuclear Information System (INIS)

    AlBalkhi, Khalid M; AlShahrani, Ibrahim; AlMadi, Abdulaziz

    2008-01-01

    The purpose of this study was to demonstrate how to establish the area center (centroid) of both the soft and hard tissues of the outline of the lateral cephalometric skull image, and to introduce the concept of a new non-anatomical centroid line. Lateral cephalometric radiographs, size 12 x 14 inch, of fifty seven adult subjects were selected based on their pleasant, balanced profile, Class I skeletal and dental relationship and no major dental malocclusion or malrelationship. The area centers (centroids) of both soft and hard tissue skull were practically established using a customized software computer program called the m -file . Connecting the two centers introduced the concept of a new non-anatomical soft and hard centroids line. (author)

  2. A physics-motivated Centroidal Voronoi Particle domain decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lin, E-mail: lin.fu@tum.de; Hu, Xiangyu Y., E-mail: xiangyu.hu@tum.de; Adams, Nikolaus A., E-mail: nikolaus.adams@tum.de

    2017-04-15

    In this paper, we propose a novel domain decomposition method for large-scale simulations in continuum mechanics by merging the concepts of Centroidal Voronoi Tessellation (CVT) and Voronoi Particle dynamics (VP). The CVT is introduced to achieve a high-level compactness of the partitioning subdomains by the Lloyd algorithm which monotonically decreases the CVT energy. The number of computational elements between neighboring partitioning subdomains, which scales the communication effort for parallel simulations, is optimized implicitly as the generated partitioning subdomains are convex and simply connected with small aspect-ratios. Moreover, Voronoi Particle dynamics employing physical analogy with a tailored equation of state is developed, which relaxes the particle system towards the target partition with good load balance. Since the equilibrium is computed by an iterative approach, the partitioning subdomains exhibit locality and the incremental property. Numerical experiments reveal that the proposed Centroidal Voronoi Particle (CVP) based algorithm produces high-quality partitioning with high efficiency, independently of computational-element types. Thus it can be used for a wide range of applications in computational science and engineering.

  3. A centroid model of species distribution with applications to the Carolina wren Thryothorus ludovicianus and house finch Haemorhous mexicanus in the United States

    Science.gov (United States)

    Huang, Qiongyu; Sauer, John R.; Swatantran, Anu; Dubayah, Ralph

    2016-01-01

    Drastic shifts in species distributions are a cause of concern for ecologists. Such shifts pose great threat to biodiversity especially under unprecedented anthropogenic and natural disturbances. Many studies have documented recent shifts in species distributions. However, most of these studies are limited to regional scales, and do not consider the abundance structure within species ranges. Developing methods to detect systematic changes in species distributions over their full ranges is critical for understanding the impact of changing environments and for successful conservation planning. Here, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. Yearly abundance-weighted range centroids are estimated. As case studies, we derive annual centroids for the Carolina wren and house finch in their ranges in the U.S. We further evaluate the first-difference correlation between species’ centroid movement and changes in winter severity, total population abundance. We also examined associations of change in centroids from sub-ranges. Change in full-range centroid movements of Carolina wren significantly correlate with snow cover days (r = −0.58). For both species, the full-range centroid shifts also have strong correlation with total abundance (r = 0.65, and 0.51 respectively). The movements of the full-range centroids of the two species are correlated strongly (up to r = 0.76) with that of the sub-ranges with more drastic population changes. Our study demonstrates the usefulness of centroids for analyzing distribution changes in a two-dimensional spatial context. Particularly it highlights applications that associate the centroid with factors such as environmental stressors, population characteristics

  4. An Adaptive Connectivity-based Centroid Algorithm for Node Positioning in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Aries Pratiarso

    2015-06-01

    Full Text Available In wireless sensor network applications, the position of nodes is randomly distributed following the contour of the observation area. A simple solution without any measurement tools is provided by range-free method. However, this method yields the coarse estimating position of the nodes. In this paper, we propose Adaptive Connectivity-based (ACC algorithm. This algorithm is a combination of Centroid as range-free based algorithm, and hop-based connectivity algorithm. Nodes have a possibility to estimate their own position based on the connectivity level between them and their reference nodes. Each node divides its communication range into several regions where each of them has a certain weight depends on the received signal strength. The weighted value is used to obtain the estimated position of nodes. Simulation result shows that the proposed algorithm has up to 3 meter error of estimated position on 100x100 square meter observation area, and up to 3 hop counts for 80 meters' communication range. The proposed algorithm performs an average error positioning up to 10 meters better than Weighted Centroid algorithm. Keywords: adaptive, connectivity, centroid, range-free.

  5. Measurement of centroid trajectory of Dragon-I electron beam

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Wang Yuan; Zhang Wenwei; Zhang Kaizhi; Li Jing; Li Chenggang; Yang Guojun

    2005-01-01

    The control of the electron beam in an intense current linear induction accelerator (LIA) is very important. The center position of the electron beam and the beam profile are two important parameters which should be measured accurately. The setup of a time-resolved measurement system and a data processing method for determining the beam center position are introduced for the purpose of obtaining Dragon-I electron beam trajectory including beam profile. The actual results show that the centroid position error can be controlled in one to two pixels. the time-resolved beam centroid trajectory of Dragon-I (18.5 MeV, 2 kA, 90 ns) is obtained recently in 10 ns interval, 3 ns exposure time with a multi-frame gated camera. The results show that the screw movement of the electron beam is mainly limited in an area with a radius of 0.5 mm and the time-resolved diameters of the beam are 8.4 mm, 8.8 mm, 8.5 mm, 9.3 mm and 7.6 mm. These results have provided a very important support to several research areas such as beam trajectory tuning and beam transmission. (authors)

  6. K-Means Algorithm Performance Analysis With Determining The Value Of Starting Centroid With Random And KD-Tree Method

    Science.gov (United States)

    Sirait, Kamson; Tulus; Budhiarti Nababan, Erna

    2017-12-01

    Clustering methods that have high accuracy and time efficiency are necessary for the filtering process. One method that has been known and applied in clustering is K-Means Clustering. In its application, the determination of the begining value of the cluster center greatly affects the results of the K-Means algorithm. This research discusses the results of K-Means Clustering with starting centroid determination with a random and KD-Tree method. The initial determination of random centroid on the data set of 1000 student academic data to classify the potentially dropout has a sse value of 952972 for the quality variable and 232.48 for the GPA, whereas the initial centroid determination by KD-Tree has a sse value of 504302 for the quality variable and 214,37 for the GPA variable. The smaller sse values indicate that the result of K-Means Clustering with initial KD-Tree centroid selection have better accuracy than K-Means Clustering method with random initial centorid selection.

  7. On the timing properties of germanium detectors: The centroid diagrams of prompt photopeaks and Compton events

    International Nuclear Information System (INIS)

    Penev, I.; Andrejtscheff, W.; Protochristov, Ch.; Zhelev, Zh.

    1987-01-01

    In the applications of the generalized centroid shift method with germanium detectors, the energy dependence of the time centroids of prompt photopeaks (zero-time line) and of Compton background events reveal a peculiar behavior crossing each other at about 100 keV. The effect is plausibly explained as associated with the ratio of γ-quanta causing the photoeffect and Compton scattering, respectively, at the boundaries of the detector. (orig.)

  8. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications

    International Nuclear Information System (INIS)

    Davidson, Ronald C.; Logan, B. Grant

    2011-01-01

    Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.

  9. A Novel Approach Based on MEMS-Gyro's Data Deep Coupling for Determining the Centroid of Star Spot

    Directory of Open Access Journals (Sweden)

    Xing Fei

    2012-01-01

    Full Text Available The traditional approach of star tracker for determining the centroid of spot requires enough energy and good shape, so a relatively long exposure time and stable three-axis state become necessary conditions to maintain high accuracy, these limit its update rate and dynamic performance. In view of these issues, this paper presents an approach for determining the centroid of star spot which based on MEMS-Gyro's data deep coupling, it achieves the deep fusion of the data of star tracker and MEMS-Gyro at star map level through the introduction of EKF. The trajectory predicted by using the angular velocity of three axes can be used to set the extraction window, this enhances the dynamic performance because of the accurate extraction when the satellite has angular speed. The optimal estimations of the centroid position and the drift in the output signal of MEMS-Gyro through this approach reduce the influence of noise of the detector on accuracy of the traditional approach for determining the centroid and effectively correct the output signal of MEMS-Gyro. At the end of this paper, feasibility of this approach is verified by simulation.

  10. A double inequality for bounding Toader mean by the centroidal mean

    Indian Academy of Sciences (India)

    A double inequality for bounding Toader mean by the centroidal mean. YUN HUA1,∗ and FENG QI2. 1Department of Information Engineering, Weihai Vocational College, Weihai City,. Shandong Province 264210, China. 2College of Mathematics, Inner Mongolia University for Nationalities, Tongliao City,. Inner Mongolia ...

  11. A walk-free centroid method for lifetime measutement of 207Pb 569.7 keV state

    International Nuclear Information System (INIS)

    Gu Jiahui; Liu Jingyi; Xiao Genlai

    1988-01-01

    An improvement have been made in acquiring data of delayed coincidence spectra with ND-620 data acquisition system and off-line data analysis program. The delayed and anti-delayed coincidence spectra can be obtained in one run. The difference of their centroids is the mean lifetime τ. The centroid position of a delayed coincidence spectrum is the zero time of another delayed coincidence spectrum, so the requirement of measuring prompt time spectrum is avoided. The walk of prompt and delayed coincidence spectrum coming from different run are resolved and the walk during the measurement is compensated partly. The delayed coincidence time spectra of 207 Pb 569.7 keV state are measured and the half lifetime is calculated via three different methods (slop method, convolution method, centroid shift). The final value of half lifetime is 129.5±1.4ps. THe experimental reduced transition probability is compared with theoretical values

  12. A double inequality for bounding Toader mean by the centroidal mean

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 124; Issue 4. A double inequality for bounding Toader mean by the centroidal mean. Yun Hua Feng Qi.

  13. Performance evaluation of the spectral centroid downshift method for attenuation estimation.

    Science.gov (United States)

    Samimi, Kayvan; Varghese, Tomy

    2015-05-01

    Estimation of frequency-dependent ultrasonic attenuation is an important aspect of tissue characterization. Along with other acoustic parameters studied in quantitative ultrasound, the attenuation coefficient can be used to differentiate normal and pathological tissue. The spectral centroid downshift (CDS) method is one the most common frequencydomain approaches applied to this problem. In this study, a statistical analysis of this method's performance was carried out based on a parametric model of the signal power spectrum in the presence of electronic noise. The parametric model used for the power spectrum of received RF data assumes a Gaussian spectral profile for the transmit pulse, and incorporates effects of attenuation, windowing, and electronic noise. Spectral moments were calculated and used to estimate second-order centroid statistics. A theoretical expression for the variance of a maximum likelihood estimator of attenuation coefficient was derived in terms of the centroid statistics and other model parameters, such as transmit pulse center frequency and bandwidth, RF data window length, SNR, and number of regression points. Theoretically predicted estimation variances were compared with experimentally estimated variances on RF data sets from both computer-simulated and physical tissue-mimicking phantoms. Scan parameter ranges for this study were electronic SNR from 10 to 70 dB, transmit pulse standard deviation from 0.5 to 4.1 MHz, transmit pulse center frequency from 2 to 8 MHz, and data window length from 3 to 17 mm. Acceptable agreement was observed between theoretical predictions and experimentally estimated values with differences smaller than 0.05 dB/cm/MHz across the parameter ranges investigated. This model helps predict the best attenuation estimation variance achievable with the CDS method, in terms of said scan parameters.

  14. Differential computation method used to calibrate the angle-centroid relationship in coaxial reverse Hartmann test

    Science.gov (United States)

    Li, Xinji; Hui, Mei; Zhao, Zhu; Liu, Ming; Dong, Liquan; Kong, Lingqin; Zhao, Yuejin

    2018-05-01

    A differential computation method is presented to improve the precision of calibration for coaxial reverse Hartmann test (RHT). In the calibration, the accuracy of the distance measurement greatly influences the surface shape test, as demonstrated in the mathematical analyses. However, high-precision absolute distance measurement is difficult in the calibration. Thus, a differential computation method that only requires the relative distance was developed. In the proposed method, a liquid crystal display screen successively displayed two regular dot matrix patterns with different dot spacing. In a special case, images on the detector exhibited similar centroid distributions during the reflector translation. Thus, the critical value of the relative displacement distance and the centroid distributions of the dots on the detector were utilized to establish the relationship between the rays at certain angles and the detector coordinates. Experiments revealed the approximately linear behavior of the centroid variation with the relative displacement distance. With the differential computation method, we increased the precision of traditional calibration 10-5 rad root mean square. The precision of the RHT was increased by approximately 100 nm.

  15. Improvement of correlation-based centroiding methods for point source Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Li, Xuxu; Li, Xinyang; wang, Caixia

    2018-03-01

    This paper proposes an efficient approach to decrease the computational costs of correlation-based centroiding methods used for point source Shack-Hartmann wavefront sensors. Four typical similarity functions have been compared, i.e. the absolute difference function (ADF), ADF square (ADF2), square difference function (SDF), and cross-correlation function (CCF) using the Gaussian spot model. By combining them with fast search algorithms, such as three-step search (TSS), two-dimensional logarithmic search (TDL), cross search (CS), and orthogonal search (OS), computational costs can be reduced drastically without affecting the accuracy of centroid detection. Specifically, OS reduces calculation consumption by 90%. A comprehensive simulation indicates that CCF exhibits a better performance than other functions under various light-level conditions. Besides, the effectiveness of fast search algorithms has been verified.

  16. Feature selection and nearest centroid classification for protein mass spectrometry

    Directory of Open Access Journals (Sweden)

    Levner Ilya

    2005-03-01

    Full Text Available Abstract Background The use of mass spectrometry as a proteomics tool is poised to revolutionize early disease diagnosis and biomarker identification. Unfortunately, before standard supervised classification algorithms can be employed, the "curse of dimensionality" needs to be solved. Due to the sheer amount of information contained within the mass spectra, most standard machine learning techniques cannot be directly applied. Instead, feature selection techniques are used to first reduce the dimensionality of the input space and thus enable the subsequent use of classification algorithms. This paper examines feature selection techniques for proteomic mass spectrometry. Results This study examines the performance of the nearest centroid classifier coupled with the following feature selection algorithms. Student-t test, Kolmogorov-Smirnov test, and the P-test are univariate statistics used for filter-based feature ranking. From the wrapper approaches we tested sequential forward selection and a modified version of sequential backward selection. Embedded approaches included shrunken nearest centroid and a novel version of boosting based feature selection we developed. In addition, we tested several dimensionality reduction approaches, namely principal component analysis and principal component analysis coupled with linear discriminant analysis. To fairly assess each algorithm, evaluation was done using stratified cross validation with an internal leave-one-out cross-validation loop for automated feature selection. Comprehensive experiments, conducted on five popular cancer data sets, revealed that the less advocated sequential forward selection and boosted feature selection algorithms produce the most consistent results across all data sets. In contrast, the state-of-the-art performance reported on isolated data sets for several of the studied algorithms, does not hold across all data sets. Conclusion This study tested a number of popular feature

  17. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de.

    1986-01-01

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied, applied to a nine heated tube bundle experimental data set. (Author) [pt

  18. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de.

    1986-01-01

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied to a nine heated tube bundle experimental data set. (Author) [pt

  19. (E)-3-[4-(Pent-yloxy)phen-yl]-1-phenyl-prop-2-en-1-one.

    Science.gov (United States)

    Abbas, Asghar; Khawar Rauf, M; Bolte, Michael; Hasan, Aurangzeb

    2009-05-14

    The title compound, C(20)H(22)O(2), crystallizes with two independent mol-ecules in the asymmetric unit. In each mol-ecule, all the non-H atoms lie in a common plane (r.m.s. deviations of 0.098 and 0.079 Å). There is a π-π stacking inter-action in the crystal structure. The central aromatic rings of the two mol-ecules, which are stacked head-to-tail one above the other, are separated by centroid-to-centroid distances of 3.872 (13) and 3.999 (10) Å.

  20. Centroid and Theoretical Rotation: Justification for Their Use in Q Methodology Research

    Science.gov (United States)

    Ramlo, Sue

    2016-01-01

    This manuscript's purpose is to introduce Q as a methodology before providing clarification about the preferred factor analytical choices of centroid and theoretical (hand) rotation. Stephenson, the creator of Q, designated that only these choices allowed for scientific exploration of subjectivity while not violating assumptions associated with…

  1. Target Centroid Position Estimation of Phase-Path Volume Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Fengjun Hu

    2016-01-01

    Full Text Available For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction.

  2. Analysis of the positon resolution in centroid measurements in MWPC

    International Nuclear Information System (INIS)

    Gatti, E.; Longoni, A.

    1981-01-01

    Resolution limits in avalanche localization along the anode wires of an MWPC with cathodes connected by resistors and equally spaced amplifiers, are evaluated. A simple weighted-centroid method and a highly linear method based on a linear centroid finding filter, are considered. The contributions to the variance of the estimator of the avalanche position, due to the series noise of the amplifiers and to the thermal noise of the resistive line are separately calculated and compared. A comparison is made with the resolution of the MWPC with isolated cathodes. The calculations are performed with a distributed model of the diffusive line formed by the cathodes and the resistors. A comparison is also made with the results obtained with a simple lumped model of the diffusive line. A number of graphs useful in determining the best parameters of a MWPC, with a specified position and time resolution, are given. It has been found that, for short resolution times, an MWPC with cathodes connected by resitors presents better resolution (lower variance of the estimator of the avalanche position) than an MWPC with isolated cathodes. Conversely, for long resolution times, the variance of the estimator of the avalanche position is lower in an MWPC with isolated cathodes. (orig.)

  3. Diffeomorphic Iterative Centroid Methods for Template Estimation on Large Datasets

    OpenAIRE

    Cury , Claire; Glaunès , Joan Alexis; Colliot , Olivier

    2014-01-01

    International audience; A common approach for analysis of anatomical variability relies on the stimation of a template representative of the population. The Large Deformation Diffeomorphic Metric Mapping is an attractive framework for that purpose. However, template estimation using LDDMM is computationally expensive, which is a limitation for the study of large datasets. This paper presents an iterative method which quickly provides a centroid of the population in the shape space. This centr...

  4. FINGERPRINT MATCHING BASED ON PORE CENTROIDS

    Directory of Open Access Journals (Sweden)

    S. Malathi

    2011-05-01

    Full Text Available In recent years there has been exponential growth in the use of bio- metrics for user authentication applications. Automated Fingerprint Identification systems have become popular tool in many security and law enforcement applications. Most of these systems rely on minutiae (ridge ending and bifurcation features. With the advancement in sensor technology, high resolution fingerprint images (1000 dpi pro- vide micro level of features (pores that have proven to be useful fea- tures for identification. In this paper, we propose a new strategy for fingerprint matching based on pores by reliably extracting the pore features The extraction of pores is done by Marker Controlled Wa- tershed segmentation method and the centroids of each pore are con- sidered as feature vectors for matching of two fingerprint images. Experimental results shows that the proposed method has better per- formance with lower false rates and higher accuracy.

  5. Ce3+ 5d-centroid shift and vacuum referred 4f-electron binding energies of all lanthanide impurities in 150 different compounds

    International Nuclear Information System (INIS)

    Dorenbos, Pieter

    2013-01-01

    A review on the wavelengths of all five 4f–5d transitions for Ce 3+ in about 150 different inorganic compounds (fluorides, chlorides, bromides, iodides, oxides, sulfides, selenides, nitrides) is presented. It provides data on the centroid shift and the crystal field splitting of the 5d-configuration which are then used to estimate the Eu 2+ inter 4f-electron Coulomb repulsion energy U(6,A) in compound A. The four semi-empirical models (the redshift model, the centroid shift model, the charge transfer model, and the chemical shift model) on lanthanide levels that were developed past 12 years are briefly reviewed. It will be demonstrated how those models together with the collected data of this work and elsewhere can be united to construct schemes that contain the binding energy of electrons in the 4f and 5d states for each divalent and each trivalent lanthanide ion relative to the vacuum energy. As example the vacuum referred binding energy schemes for LaF 3 and La 2 O 3 will be constructed. - Highlights: ► An compilation on all five Ce 3+ 4f–5d energies in 150 inorganic compounds is presented. ► The relationship between the 5d centroid shift and host cation electronegativity id demonstrated. ► The electronic structure scheme of the lanthanides in La 2 O 3 and LaF 3 is presented.

  6. Automatic localization of the left ventricular blood pool centroid in short axis cardiac cine MR images.

    Science.gov (United States)

    Tan, Li Kuo; Liew, Yih Miin; Lim, Einly; Abdul Aziz, Yang Faridah; Chee, Kok Han; McLaughlin, Robert A

    2018-06-01

    In this paper, we develop and validate an open source, fully automatic algorithm to localize the left ventricular (LV) blood pool centroid in short axis cardiac cine MR images, enabling follow-on automated LV segmentation algorithms. The algorithm comprises four steps: (i) quantify motion to determine an initial region of interest surrounding the heart, (ii) identify potential 2D objects of interest using an intensity-based segmentation, (iii) assess contraction/expansion, circularity, and proximity to lung tissue to score all objects of interest in terms of their likelihood of constituting part of the LV, and (iv) aggregate the objects into connected groups and construct the final LV blood pool volume and centroid. This algorithm was tested against 1140 datasets from the Kaggle Second Annual Data Science Bowl, as well as 45 datasets from the STACOM 2009 Cardiac MR Left Ventricle Segmentation Challenge. Correct LV localization was confirmed in 97.3% of the datasets. The mean absolute error between the gold standard and localization centroids was 2.8 to 4.7 mm, or 12 to 22% of the average endocardial radius. Graphical abstract Fully automated localization of the left ventricular blood pool in short axis cardiac cine MR images.

  7. Lifetime measurements in {sup 170}Yb using the generalized centroid difference method

    Energy Technology Data Exchange (ETDEWEB)

    Karayonchev, Vasil; Regis, Jean-Marc; Jolie, Jan; Dannhoff, Moritz; Saed-Samii, Nima; Blazhev, Andrey [Institute of Nuclear Physics, University of Cologne, Cologne (Germany)

    2016-07-01

    An experiment using the electronic γ-γ ''fast-timing'' technique was performed at the 10 MV Tandem Van-De-Graaff accelerator of the Institute for Nuclear Physics, Cologne in order to measure lifetimes of the yrast states in {sup 170}Yb. The lifetime of the first 2{sup +} state was determined using the slope method, which means by fitting an exponential decay to the ''slope'' seen in the energy-gated time-difference spectra. The value of τ=2.201(57) ns is in good agreement with the lifetimes measured using other techniques. The lifetimes of the first 4{sup +} and the 6{sup +} states are determined for the first time. They are in the ps range and were measured using the generalized centroid difference method, an extension of the well-known centroid-shift method and developed for fast-timing arrays. The derived reduced transition probabilities B(E2) values are compared with calculations done using the confined beta soft model and show good agreement within the experimental uncertainties.

  8. The strengths and limitations of effective centroid force models explored by studying isotopic effects in liquid water

    Science.gov (United States)

    Yuan, Ying; Li, Jicun; Li, Xin-Zheng; Wang, Feng

    2018-05-01

    The development of effective centroid potentials (ECPs) is explored with both the constrained-centroid and quasi-adiabatic force matching using liquid water as a test system. A trajectory integrated with the ECP is free of statistical noises that would be introduced when the centroid potential is approximated on the fly with a finite number of beads. With the reduced cost of ECP, challenging experimental properties can be studied in the spirit of centroid molecular dynamics. The experimental number density of H2O is 0.38% higher than that of D2O. With the ECP, the H2O number density is predicted to be 0.42% higher, when the dispersion term is not refit. After correction of finite size effects, the diffusion constant of H2O is found to be 21% higher than that of D2O, which is in good agreement with the 29.9% higher diffusivity for H2O observed experimentally. Although the ECP is also able to capture the redshifts of both the OH and OD stretching modes in liquid water, there are a number of properties that a classical simulation with the ECP will not be able to recover. For example, the heat capacities of H2O and D2O are predicted to be almost identical and higher than the experimental values. Such a failure is simply a result of not properly treating quantized vibrational energy levels when the trajectory is propagated with classical mechanics. Several limitations of the ECP based approach without bead population reconstruction are discussed.

  9. Modification of backgammon shape cathode and graded charge division readout method for a novel triple charge division centroid finding method

    International Nuclear Information System (INIS)

    Javanmardi, F.; Matoba, M.; Sakae, T.

    1996-01-01

    Triple Charge Division (TCD) centroid finding method that uses modified pattern of Backgammon Shape Cathode (MBSC) is introduced for medium range length position sensitive detectors with optimum numbers of cathode segments. MBSC pattern has three separated areas and uses saw tooth like insulator gaps for separating the areas. Side areas of the MBSC pattern are severed by a central common area. Size of the central area is twice of the size of both sides. Whereas central area is the widest area among three, both sides' areas have the main role in position sensing. With the same resolution and linearity, active region of original Backgammon pattern increases twice by using MBSC pattern, and with the same length, linearity of TCD centroid finding is much better than Backgammon charge division readout method. Linearity prediction of TCD centroid finding and experimental results conducted us to find an optimum truncation of the apices of MBCS pattern in the central area. The TCD centroid finding has an especial readout method since charges must be collected from two segments in both sides and from three segments in the central area of MBSC pattern. The so called Graded Charge Division (GCD) is the especial readout method for TCD. The GCD readout is a combination of the charge division readout and sequence grading of serial segments. Position sensing with TCD centroid finding and GCD readout were done by two sizes MBSC patterns (200mm and 80mm) and Spatial resolution about 1% of the detector length is achieved

  10. Hough transform used on the spot-centroiding algorithm for the Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Chia, Chou-Min; Huang, Kuang-Yuh; Chang, Elmer

    2016-01-01

    An approach to the spot-centroiding algorithm for the Shack-Hartmann wavefront sensor (SHWS) is presented. The SHWS has a common problem, in that while measuring high-order wavefront distortion, the spots may exceed each of the subapertures, which are used to restrict the displacement of spots. This artificial restriction may limit the dynamic range of the SHWS. When using the SHWS to measure adaptive optics or aspheric lenses, the accuracy of the traditional spot-centroiding algorithm may be uncertain because the spots leave or cross the confined area of the subapertures. The proposed algorithm combines the Hough transform with an artificial neural network, which requires no confined subapertures, to increase the dynamic range of the SHWS. This algorithm is then explored in comprehensive simulations and the results are compared with those of the existing algorithm.

  11. CentroidFold: a web server for RNA secondary structure prediction

    OpenAIRE

    Sato, Kengo; Hamada, Michiaki; Asai, Kiyoshi; Mituyama, Toutai

    2009-01-01

    The CentroidFold web server (http://www.ncrna.org/centroidfold/) is a web application for RNA secondary structure prediction powered by one of the most accurate prediction engine. The server accepts two kinds of sequence data: a single RNA sequence and a multiple alignment of RNA sequences. It responses with a prediction result shown as a popular base-pair notation and a graph representation. PDF version of the graph representation is also available. For a multiple alignment sequence, the ser...

  12. Prediction of RNA secondary structure using generalized centroid estimators.

    Science.gov (United States)

    Hamada, Michiaki; Kiryu, Hisanori; Sato, Kengo; Mituyama, Toutai; Asai, Kiyoshi

    2009-02-15

    Recent studies have shown that the methods for predicting secondary structures of RNAs on the basis of posterior decoding of the base-pairing probabilities has an advantage with respect to prediction accuracy over the conventionally utilized minimum free energy methods. However, there is room for improvement in the objective functions presented in previous studies, which are maximized in the posterior decoding with respect to the accuracy measures for secondary structures. We propose novel estimators which improve the accuracy of secondary structure prediction of RNAs. The proposed estimators maximize an objective function which is the weighted sum of the expected number of the true positives and that of the true negatives of the base pairs. The proposed estimators are also improved versions of the ones used in previous works, namely CONTRAfold for secondary structure prediction from a single RNA sequence and McCaskill-MEA for common secondary structure prediction from multiple alignments of RNA sequences. We clarify the relations between the proposed estimators and the estimators presented in previous works, and theoretically show that the previous estimators include additional unnecessary terms in the evaluation measures with respect to the accuracy. Furthermore, computational experiments confirm the theoretical analysis by indicating improvement in the empirical accuracy. The proposed estimators represent extensions of the centroid estimators proposed in Ding et al. and Carvalho and Lawrence, and are applicable to a wide variety of problems in bioinformatics. Supporting information and the CentroidFold software are available online at: http://www.ncrna.org/software/centroidfold/.

  13. Performance Evaluation of the Spectral Centroid Downshift Method for Attenuation Estimation

    OpenAIRE

    Samimi, Kayvan; Varghese, Tomy

    2015-01-01

    Estimation of frequency-dependent ultrasonic attenuation is an important aspect of tissue characterization. Along with other acoustic parameters studied in quantitative ultrasound, the attenuation coefficient can be used to differentiate normal and pathological tissue. The spectral centroid downshift (CDS) method is one the most common frequency-domain approaches applied to this problem. In this study, a statistical analysis of this method’s performance was carried out based on a parametric m...

  14. A Proposal to Speed up the Computation of the Centroid of an Interval Type-2 Fuzzy Set

    Directory of Open Access Journals (Sweden)

    Carlos E. Celemin

    2013-01-01

    Full Text Available This paper presents two new algorithms that speed up the centroid computation of an interval type-2 fuzzy set. The algorithms include precomputation of the main operations and initialization based on the concept of uncertainty bounds. Simulations over different kinds of footprints of uncertainty reveal that the new algorithms achieve computation time reductions with respect to the Enhanced-Karnik algorithm, ranging from 40 to 70%. The results suggest that the initialization used in the new algorithms effectively reduces the number of iterations to compute the extreme points of the interval centroid while precomputation reduces the computational cost of each iteration.

  15. Communications: On artificial frequency shifts in infrared spectra obtained from centroid molecular dynamics: Quantum liquid water

    Science.gov (United States)

    Ivanov, Sergei D.; Witt, Alexander; Shiga, Motoyuki; Marx, Dominik

    2010-01-01

    Centroid molecular dynamics (CMD) is a popular method to extract approximate quantum dynamics from path integral simulations. Very recently we have shown that CMD gas phase infrared spectra exhibit significant artificial redshifts of stretching peaks, due to the so-called "curvature problem" imprinted by the effective centroid potential. Here we provide evidence that for condensed phases, and in particular for liquid water, CMD produces pronounced artificial redshifts for high-frequency vibrations such as the OH stretching band. This peculiar behavior intrinsic to the CMD method explains part of the unexpectedly large quantum redshifts of the stretching band of liquid water compared to classical frequencies, which is improved after applying a simple and rough "harmonic curvature correction."

  16. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang

    1989-01-01

    attractive properties. An evaluation based on an existing SEASAT processor is reported. The time-domain algorithms are shown to be extremely efficient with respect to requirements on calculations and memory, and hence they are well suited to real-time systems where the Doppler estimation is based on raw SAR......After reviewing frequency-domain techniques for estimating the Doppler centroid of synthetic-aperture radar (SAR) data, the author describes a time-domain method and highlights its advantages. In particular, a nonlinear time-domain algorithm called the sign-Doppler estimator (SDE) is shown to have...... data. For offline processors where the Doppler estimation is performed on processed data, which removes the problem of partial coverage of bright targets, the ΔE estimator and the CDE (correlation Doppler estimator) algorithm give similar performance. However, for nonhomogeneous scenes it is found...

  17. MOBIUS-STRIP-LIKE COLUMNAR FUNCTIONAL CONNECTIONS ARE REVEALED IN SOMATO-SENSORY RECEPTIVE FIELD CENTROIDS.

    Directory of Open Access Journals (Sweden)

    James Joseph Wright

    2014-10-01

    Full Text Available Receptive fields of neurons in the forelimb region of areas 3b and 1 of primary somatosensory cortex, in cats and monkeys, were mapped using extracellular recordings obtained sequentially from nearly radial penetrations. Locations of the field centroids indicated the presence of a functional system, in which cortical homotypic representations of the limb surfaces are entwined in three-dimensional Mobius-strip-like patterns of synaptic connections. Boundaries of somatosensory receptive field in nested groups irregularly overlie the centroid order, and are interpreted as arising from the superposition of learned connections upon the embryonic order. Since the theory of embryonic synaptic self-organisation used to model these results was devised and earlier used to explain findings in primary visual cortex, the present findings suggest the theory may be of general application throughout cortex, and may reveal a modular functional synaptic system, which, only in some parts of the cortex, and in some species, is manifest as anatomical ordering into columns.

  18. Optimization of soy isoflavone extraction with different solvents using the simplex-centroid mixture design.

    Science.gov (United States)

    Yoshiara, Luciane Yuri; Madeira, Tiago Bervelieri; Delaroza, Fernanda; da Silva, Josemeyre Bonifácio; Ida, Elza Iouko

    2012-12-01

    The objective of this study was to optimize the extraction of different isoflavone forms (glycosidic, malonyl-glycosidic, aglycone and total) from defatted cotyledon soy flour using the simplex-centroid experimental design with four solvents of varying polarity (water, acetone, ethanol and acetonitrile). The obtained extracts were then analysed by high-performance liquid chromatography. The profile of the different soy isoflavones forms varied with different extractions solvents. Varying the solvent or mixture used, the extraction of different isoflavones was optimized using the centroid-simplex mixture design. The special cubic model best fitted to the four solvents and its combination for soy isoflavones extraction. For glycosidic isoflavones extraction, the polar ternary mixture (water, acetone and acetonitrile) achieved the best extraction; malonyl-glycosidic forms were better extracted with mixtures of water, acetone and ethanol. Aglycone isoflavones, water and acetone mixture were best extracted and total isoflavones, the best solvents were ternary mixture of water, acetone and ethanol.

  19. 4fn-15d centroid shift in lanthanides and relation with anion polarizability, covalency, and cation electronegativity

    International Nuclear Information System (INIS)

    Dorenbos, P.; Andriessen, J.; Eijk, C.W.E. van

    2003-01-01

    Data collected on the centroid shift of the 5d-configuration of Ce 3+ in oxide and fluoride compounds were recently analyzed with a model involving the correlated motion between 5d-electron and ligand electrons. The correlation effects are proportional to the polarizability of the anion ligands and it leads, like covalency, to lowering of the 5d-orbital energies. By means of ab initio Hartree-Fock-LCAO calculations including configuration interaction the contribution from covalency and correlated motion to the centroid shift are determined separately for Ce 3+ in various compounds. It will be shown that in fluoride compounds, covalency provides an insignificant contribution. In oxides, polarizability appears to be of comparable importance as covalency

  20. Improved measurements of RNA structure conservation with generalized centroid estimators

    Directory of Open Access Journals (Sweden)

    Yohei eOkada

    2011-08-01

    Full Text Available Identification of non-protein-coding RNAs (ncRNAs in genomes is acrucial task for not only molecular cell biology but alsobioinformatics. Secondary structures of ncRNAs are employed as a keyfeature of ncRNA analysis since biological functions of ncRNAs aredeeply related to their secondary structures. Although the minimumfree energy (MFE structure of an RNA sequence is regarded as the moststable structure, MFE alone could not be an appropriate measure foridentifying ncRNAs since the free energy is heavily biased by thenucleotide composition. Therefore, instead of MFE itself, severalalternative measures for identifying ncRNAs have been proposed such asthe structure conservation index (SCI and the base pair distance(BPD, both of which employ MFE structures. However, thesemeasurements are unfortunately not suitable for identifying ncRNAs insome cases including the genome-wide search and incur high falsediscovery rate. In this study, we propose improved measurements basedon SCI and BPD, applying generalized centroid estimators toincorporate the robustness against low quality multiple alignments.Our experiments show that our proposed methods achieve higher accuracythan the original SCI and BPD for not only human-curated structuralalignments but also low quality alignments produced by CLUSTALW. Furthermore, the centroid-based SCI on CLUSTAL W alignments is moreaccurate than or comparable with that of the original SCI onstructural alignments generated with RAF, a high quality structuralaligner, for which two-fold expensive computational time is requiredon average. We conclude that our methods are more suitable forgenome-wide alignments which are of low quality from the point of viewon secondary structures than the original SCI and BPD.

  1. Oscillations of centroid position and surface area of soccer teams in small-sided games

    NARCIS (Netherlands)

    Frencken, Wouter; Lemmink, Koen; Delleman, Nico; Visscher, Chris

    2011-01-01

    There is a need for a collective variable that captures the dynamics of team sports like soccer at match level. The centroid positions and surface areas of two soccer teams potentially describe the coordinated flow of attacking and defending in small-sided soccer games at team level. The aim of the

  2. An Investigation on the Use of Different Centroiding Algorithms and Star Catalogs in Astro-Geodetic Observations

    Science.gov (United States)

    Basoglu, Burak; Halicioglu, Kerem; Albayrak, Muge; Ulug, Rasit; Tevfik Ozludemir, M.; Deniz, Rasim

    2017-04-01

    In the last decade, the importance of high-precise geoid determination at local or national level has been pointed out by Turkish National Geodesy Commission. The Commission has also put objective of modernization of national height system of Turkey to the agenda. Meanwhile several projects have been realized in recent years. In Istanbul city, a GNSS/Levelling geoid was defined in 2005 for the metropolitan area of the city with an accuracy of ±3.5cm. In order to achieve a better accuracy in this area, "Local Geoid Determination with Integration of GNSS/Levelling and Astro-Geodetic Data" project has been conducted in Istanbul Technical University and Bogazici University KOERI since January 2016. The project is funded by The Scientific and Technological Research Council of Turkey. With the scope of the project, modernization studies of Digital Zenith Camera System are being carried on in terms of hardware components and software development. Accentuated subjects are the star catalogues, and centroiding algorithm used to identify the stars on the zenithal star field. During the test observations of Digital Zenith Camera System performed between 2013-2016, final results were calculated using the PSF method for star centroiding, and the second USNO CCD Astrograph Catalogue (UCAC2) for the reference star positions. This study aims to investigate the position accuracy of the star images by comparing different centroiding algorithms and available star catalogs used in astro-geodetic observations conducted with the digital zenith camera system.

  3. Two tree-formation methods for fast pattern search using nearest-neighbour and nearest-centroid matching

    NARCIS (Netherlands)

    Schomaker, Lambertus; Mangalagiu, D.; Vuurpijl, Louis; Weinfeld, M.; Schomaker, Lambert; Vuurpijl, Louis

    2000-01-01

    This paper describes tree­based classification of character images, comparing two methods of tree formation and two methods of matching: nearest neighbor and nearest centroid. The first method, Preprocess Using Relative Distances (PURD) is a tree­based reorganization of a flat list of patterns,

  4. (Carbonato-κO,O')bis-(1,10-phenan-throline-κN,N')cobalt(III) nitrate monohydrate.

    Science.gov (United States)

    Andaç, Omer; Yolcu, Zuhal; Büyükgüngör, Orhan

    2009-12-12

    The crystal structure of the title compound, [Co(CO(3))(C(12)H(8)N(2))(2)]NO(3)·H(2)O, consists of Co(III) complex cations, nitrate anions and uncoordinated water mol-ecules. The Co(III) cation is chelated by a carbonate anion and two phenanthroline ligands in a distorted octa-hedral coordination geometry. A three-dimensional supra-molecular structure is formed by O-H⋯O and C-H⋯O hydrogen bonding, C-H⋯π and aromatic π-π stacking [centroid-centroid distance = 3.995 (1)Å] inter-actions.

  5. Alteração no método centroide de avaliação da adaptabilidade genotípica Alteration of the centroid method to evaluate genotypic adaptability

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2009-03-01

    Full Text Available O objetivo deste trabalho foi alterar o método centroide de avaliação da adaptabilidade e estabilidade fenotípica de genótipos, para deixá-lo com maior sentido biológico e melhorar aspectos quantitativos e qualitativos de sua análise. A alteração se deu pela adição de mais três ideótipos, definidos de acordo com valores médios dos genótipos nos ambientes. Foram utilizados dados provenientes de um experimento sobre produção de matéria seca de 92 genótipos de alfafa (Medicago sativa realizado em blocos ao acaso, com duas repetições. Os genótipos foram submetidos a 20 cortes, no período de novembro de 2004 a junho de 2006. Cada corte foi considerado um ambiente. A inclusão dos ideótipos de maior sentido biológico (valores médios nos ambientes resultou em uma dispersão gráfica em forma de uma seta voltada para a direita, na qual os genótipos mais produtivos ficaram próximos à ponta da seta. Com a alteração, apenas cinco genótipos foram classificados nas mesmas classes do método centroide original. A figura em forma de seta proporciona uma comparação direta dos genótipos, por meio da formação de um gradiente de produtividade. A alteração no método mantém a facilidade de interpretação dos resultados para a recomendação dos genótipos presente no método original e não permite duplicidade de interpretação dos resultados.ABSTRACT The objective of this work was to modify the centroid method of evaluation of phenotypic adaptability and the phenotype stability of genotypes in order for the method to make greater biological sense and improve its quantitative and qualitative performance. The method was modified by means of the inclusion of three additional ideotypes defined in accordance with the genotypes' average yield in the environments tested. The alfalfa (Medicago sativa L. forage yield of 92 genotypes was used. The trial had a randomized block design, with two replicates, and the data were used to

  6. THE ENERGY DEPENDENCE OF THE CENTROID FREQUENCY AND PHASE LAG OF THE QUASI-PERIODIC OSCILLATIONS IN GRS 1915+105

    International Nuclear Information System (INIS)

    Qu, J. L.; Lu, F. J.; Lu, Y.; Song, L. M.; Zhang, S.; Wang, J. M.; Ding, G. Q.

    2010-01-01

    We present a study of the centroid frequencies and phase lags of quasi-periodic oscillations (QPOs) as functions of photon energy for GRS 1915+105. It is found that the centroid frequencies of the 0.5-10 Hz QPOs and their phase lags are both energy dependent, and there exists an anticorrelation between the QPO frequency and phase lag. These new results challenge the popular QPO models, because none of them can fully explain the observed properties. We suggest that the observed QPO phase lags are partially due to the variation of the QPO frequency with energy, especially for those with frequency higher than 3.5 Hz.

  7. User Manual and Supporting Information for Library of Codes for Centroidal Voronoi Point Placement and Associated Zeroth, First, and Second Moment Determination; TOPICAL

    International Nuclear Information System (INIS)

    BURKARDT, JOHN; GUNZBURGER, MAX; PETERSON, JANET; BRANNON, REBECCA M.

    2002-01-01

    The theory, numerical algorithm, and user documentation are provided for a new ''Centroidal Voronoi Tessellation (CVT)'' method of filling a region of space (2D or 3D) with particles at any desired particle density. ''Clumping'' is entirely avoided and the boundary is optimally resolved. This particle placement capability is needed for any so-called ''mesh-free'' method in which physical fields are discretized via arbitrary-connectivity discrete points. CVT exploits efficient statistical methods to avoid expensive generation of Voronoi diagrams. Nevertheless, if a CVT particle's Voronoi cell were to be explicitly computed, then it would have a centroid that coincides with the particle itself and a minimized rotational moment. The CVT code provides each particle's volume and centroid, and also the rotational moment matrix needed to approximate a particle by an ellipsoid (instead of a simple sphere). DIATOM region specification is supported

  8. An improved Q estimation approach: the weighted centroid frequency shift method

    Science.gov (United States)

    Li, Jingnan; Wang, Shangxu; Yang, Dengfeng; Dong, Chunhui; Tao, Yonghui; Zhou, Yatao

    2016-06-01

    Seismic wave propagation in subsurface media suffers from absorption, which can be quantified by the quality factor Q. Accurate estimation of the Q factor is of great importance for the resolution enhancement of seismic data, precise imaging and interpretation, and reservoir prediction and characterization. The centroid frequency shift method (CFS) is currently one of the most commonly used Q estimation methods. However, for seismic data that contain noise, the accuracy and stability of Q extracted using CFS depend on the choice of frequency band. In order to reduce the influence of frequency band choices and obtain Q with greater precision and robustness, we present an improved CFS Q measurement approach—the weighted CFS method (WCFS), which incorporates a Gaussian weighting coefficient into the calculation procedure of the conventional CFS. The basic idea is to enhance the proportion of advantageous frequencies in the amplitude spectrum and reduce the weight of disadvantageous frequencies. In this novel method, we first construct a Gauss function using the centroid frequency and variance of the reference wavelet. Then we employ it as the weighting coefficient for the amplitude spectrum of the original signal. Finally, the conventional CFS is adopted for the weighted amplitude spectrum to extract the Q factor. Numerical tests of noise-free synthetic data demonstrate that the WCFS is feasible and efficient, and produces more accurate results than the conventional CFS. Tests for noisy synthetic data indicate that the new method has better anti-noise capability than the CFS. The application to field vertical seismic profile (VSP) data further demonstrates its validity5.

  9. Shack-Hartmann centroid detection method based on high dynamic range imaging and normalization techniques

    International Nuclear Information System (INIS)

    Vargas, Javier; Gonzalez-Fernandez, Luis; Quiroga, Juan Antonio; Belenguer, Tomas

    2010-01-01

    In the optical quality measuring process of an optical system, including diamond-turning components, the use of a laser light source can produce an undesirable speckle effect in a Shack-Hartmann (SH) CCD sensor. This speckle noise can deteriorate the precision and accuracy of the wavefront sensor measurement. Here we present a SH centroid detection method founded on computer-based techniques and capable of measurement in the presence of strong speckle noise. The method extends the dynamic range imaging capabilities of the SH sensor through the use of a set of different CCD integration times. The resultant extended range spot map is normalized to accurately obtain the spot centroids. The proposed method has been applied to measure the optical quality of the main optical system (MOS) of the mid-infrared instrument telescope smulator. The wavefront at the exit of this optical system is affected by speckle noise when it is illuminated by a laser source and by air turbulence because it has a long back focal length (3017 mm). Using the proposed technique, the MOS wavefront error was measured and satisfactory results were obtained.

  10. The centroid shift of the 5d levels of Ce3+ with respect to the 4f levels in ionic crystals, a theoretical investigation

    International Nuclear Information System (INIS)

    Andriessen, J.; Dorenbos, P.; Eijk, C.W.E van

    2002-01-01

    The centroid shifts of the 5d level of Ce 3+ in BaF 2 , LaAlO 3 and LaCl 3 have been calculated using the ionic cluster approach. By applying configuration interaction as extension of the basic HF-LCAO approach the dynamical polarization contribution to the centroid shift was calculated. This was found to be only successful if basis sets are used optimized for polarization of the anions

  11. The mirror symmetric centroid difference method for picosecond lifetime measurements via {gamma}-{gamma} coincidences using very fast LaBr{sub 3}(Ce) scintillator detectors

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M., E-mail: regis@ikp.uni-koeln.d [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Pascovici, G.; Jolie, J.; Rudigier, M. [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2010-10-01

    The ultra-fast timing technique was introduced in the 1980s and is capable of measuring picosecond lifetimes of nuclear excited states with about 3 ps accuracy. Very fast scintillator detectors are connected to an electronic timing circuit and detector vs. detector time spectra are analyzed by means of the centroid shift method. The very good 3% energy resolution of the nowadays available LaBr{sub 3}(Ce) scintillator detectors for {gamma}-rays has made possible an extension of the well-established fast timing technique. The energy dependent fast timing characteristics or the prompt curve, respectively, of the LaBr{sub 3}(Ce) scintillator detector has been measured using a standard {sup 152}Eu {gamma}-ray source. For any energy combination in the range of 200keVcentroid shift method providing very attractive features for picosecond lifetime measurements is presented. The mirror symmetric centroid difference method takes advantage of the symmetry obtained when performing {gamma}-{gamma} lifetime measurements using a pair of almost identical very fast scintillator detectors. In particular cases, the use of the mirror symmetric centroid difference method also allows the direct determination of picosecond lifetimes, hence without the need of calibrating the prompt curve.

  12. Quantum size correction to the work function and centroid of excess charge in positively ionized simple metal clusters

    International Nuclear Information System (INIS)

    Payami, M.

    2004-01-01

    In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct position of the centroid of excess charge in positively charged simple metal clusters with different r s values (2≤ r s ≥ 7). For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes 2≤ N ≥100 in the framework of local spin-density approximation and stabilized jellium model as well as simple jellium model with rigid jellium. Secondly, we have fitted our results to the asymptotic ionization formulas both with and without the size correction to the work function. The results of fittings show that the formula containing the size correction predict a correct position of the centroid inside the jellium while the other predicts a false position, outside the jellium sphere

  13. Demonstration of biased membrane static figure mapping by optical beam subpixel centroid shift

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Fabrizio, E-mail: fpinto@jazanu.edu.sa [Laboratory for Quantum Vacuum Applications, Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, Gizan 45142 (Saudi Arabia)

    2016-06-10

    The measurement of Casimir forces by means of condenser microphones has been shown to be quite promising since its early introduction almost half-a-century ago. However, unlike the remarkable progress achieved in characterizing the vibrating membrane in the dynamical case, the accurate determination of the membrane static figure under electrostatic bias remains a challenge. In this paper, we discuss our first data obtained by measuring the centroid shift of an optical beam with subpixel accuracy by charge coupled device (CCD) and by an extensive analysis of noise sources present in the experimental setup.

  14. Quantum size correction to the work function and the centroid of excess charge in positively ionized simple metal clusters

    Directory of Open Access Journals (Sweden)

    M. Payami

    2003-12-01

    Full Text Available  In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct position of the centroid of excess charge in positively charged simple metal clusters with different values . For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes in the framework of local spin-density approximation and stabilized jellium model (SJM as well as simple jellium model (JM with rigid jellium. Secondly, we have fitted our results to the asymptotic ionization formulas both with and without the size correction to the work function. The results of fittings show that the formula containing the size correction predict a correct position of the centroid inside the jellium while the other predicts a false position, outside the jellium sphere.

  15. Modelling Perception of Structure and Affect in Music: Spectral Centroid and Wishart's Red Bird

    Directory of Open Access Journals (Sweden)

    Roger T. Dean

    2011-12-01

    Full Text Available Pearce (2011 provides a positive and interesting response to our article on time series analysis of the influences of acoustic properties on real-time perception of structure and affect in a section of Trevor Wishart’s Red Bird (Dean & Bailes, 2010. We address the following topics raised in the response and our paper. First, we analyse in depth the possible influence of spectral centroid, a timbral feature of the acoustic stream distinct from the high level general parameter we used initially, spectral flatness. We find that spectral centroid, like spectral flatness, is not a powerful predictor of real-time responses, though it does show some features that encourage its continued consideration. Second, we discuss further the issue of studying both individual responses, and as in our paper, group averaged responses. We show that a multivariate Vector Autoregression model handles the grand average series quite similarly to those of individual members of our participant groups, and we analyse this in greater detail with a wide range of approaches in work which is in press and continuing. Lastly, we discuss the nature and intent of computational modelling of cognition using acoustic and music- or information theoretic data streams as predictors, and how the music- or information theoretic approaches may be applied to electroacoustic music, which is ‘sound-based’ rather than note-centred like Western classical music.

  16. Bis(8-hy-droxy-1-methyl-quinolin-1-ium) bis-(1,2-dicyano-ethene-1,2-dithiol-ato)nickelate(II) dihydrate.

    Science.gov (United States)

    Guan, Zhi-Heng; Jiang, Zhang; Wang, Fang-Ming

    2011-12-01

    In the title ion-pair complex, (C(10)H(10)NO)(2)[Ni(C(4)N(2)S(2))(2)]·2H(2)O, the anion has crystallographically imposed centre of symmetry. The Ni(II) atom exhibits a slightly distorted square-planar coordination geometry. In the crystal, the water mol-ecule links anions and cations into a three-dimensional network via O-H⋯N, O-H⋯S and O-H⋯O hydrogen bonds. The structure is further stabilized by weak S⋯π contacts [S⋯centroid = 3.8047 (9) Å] and π-π stacking inter-actions [centriod-centroid distance = 3.8653 (7) Å].

  17. The centroidal algorithm in molecular similarity and diversity calculations on confidential datasets

    Science.gov (United States)

    Trepalin, Sergey; Osadchiy, Nikolay

    2005-09-01

    Chemical structure provides exhaustive description of a compound, but it is often proprietary and thus an impediment in the exchange of information. For example, structure disclosure is often needed for the selection of most similar or dissimilar compounds. Authors propose a centroidal algorithm based on structural fragments (screens) that can be efficiently used for the similarity and diversity selections without disclosing structures from the reference set. For an increased security purposes, authors recommend that such set contains at least some tens of structures. Analysis of reverse engineering feasibility showed that the problem difficulty grows with decrease of the screen's radius. The algorithm is illustrated with concrete calculations on known steroidal, quinoline, and quinazoline drugs. We also investigate a problem of scaffold identification in combinatorial library dataset. The results show that relatively small screens of radius equal to 2 bond lengths perform well in the similarity sorting, while radius 4 screens yield better results in diversity sorting. The software implementation of the algorithm taking SDF file with a reference set generates screens of various radii which are subsequently used for the similarity and diversity sorting of external SDFs. Since the reverse engineering of the reference set molecules from their screens has the same difficulty as the RSA asymmetric encryption algorithm, generated screens can be stored openly without further encryption. This approach ensures an end user transfers only a set of structural fragments and no other data. Like other algorithms of encryption, the centroid algorithm cannot give 100% guarantee of protecting a chemical structure from dataset, but probability of initial structure identification is very small-order of 10-40 in typical cases.

  18. Crystal structure of a looped-chain CoII coordination polymer: catena-poly[[bis-(nitrato-κO)cobalt(II)]bis-[μ-bis-(pyridin-3-ylmeth-yl)sulfane-κ2N:N'

    Science.gov (United States)

    Moon, Suk-Hee; Seo, Joobeom; Park, Ki-Min

    2017-11-01

    The asymmetric unit of the title compound, [Co(NO 3 ) 2 (C 12 H 12 N 2 S) 2 ] n , contains a bis-(pyridin-3-ylmeth-yl)sulfane ( L ) ligand, an NO 3 - anion and half a Co II cation, which lies on an inversion centre. The Co II cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the Co II centre adopts a distorted octa-hedral geometry. Two symmetry-related L ligands are connected by two symmetry-related Co II cations, forming a 20-membered cyclic dimer, in which the Co II atoms are separated by 10.2922 (7) Å. The cyclic dimers are connected to each other by sharing Co II atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Inter-molecular C-H⋯π (H⋯ring centroid = 2.89 Å) inter-actions between one pair of corresponding L ligands and C-H⋯O hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by inter-molecular π-π stacking inter-actions [centroid-to-centroid distance = 3.8859 (14) Å] and C-H⋯π hydrogen bonds (H⋯ring centroid = 2.65 Å), leading to the formation of layers parallel to (101). These layers are further connected through C-H⋯O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supra-molecular architecture.

  19. Centroid and full-width at half maximum uncertainties of histogrammed data with an underlying Gaussian distribution -- The moments method

    International Nuclear Information System (INIS)

    Valentine, J.D.; Rana, A.E.

    1996-01-01

    The effect of approximating a continuous Gaussian distribution with histogrammed data are studied. The expressions for theoretical uncertainties in centroid and full-width at half maximum (FWHM), as determined by calculation of moments, are derived using the error propagation method for a histogrammed Gaussian distribution. The results are compared with the corresponding pseudo-experimental uncertainties for computer-generated histogrammed Gaussian peaks to demonstrate the effect of binning the data. It is shown that increasing the number of bins in the histogram improves the continuous distribution approximation. For example, a FWHM ≥ 9 and FWHM ≥ 12 bins are needed to reduce the pseudo-experimental standard deviation of FWHM to within ≥5% and ≥1%, respectively, of the theoretical value for a peak containing 10,000 counts. In addition, the uncertainties in the centroid and FWHM as a function of peak area are studied. Finally, Sheppard's correction is applied to partially correct for the binning effect

  20. The Single-Molecule Centroid Localization Algorithm Improves the Accuracy of Fluorescence Binding Assays.

    Science.gov (United States)

    Hua, Boyang; Wang, Yanbo; Park, Seongjin; Han, Kyu Young; Singh, Digvijay; Kim, Jin H; Cheng, Wei; Ha, Taekjip

    2018-03-13

    Here, we demonstrate that the use of the single-molecule centroid localization algorithm can improve the accuracy of fluorescence binding assays. Two major artifacts in this type of assay, i.e., nonspecific binding events and optically overlapping receptors, can be detected and corrected during analysis. The effectiveness of our method was confirmed by measuring two weak biomolecular interactions, the interaction between the B1 domain of streptococcal protein G and immunoglobulin G and the interaction between double-stranded DNA and the Cas9-RNA complex with limited sequence matches. This analysis routine requires little modification to common experimental protocols, making it readily applicable to existing data and future experiments.

  1. Simplex-centroid mixture formulation for optimised composting of kitchen waste.

    Science.gov (United States)

    Abdullah, N; Chin, N L

    2010-11-01

    Composting is a good recycling method to fully utilise all the organic wastes present in kitchen waste due to its high nutritious matter within the waste. In this present study, the optimised mixture proportions of kitchen waste containing vegetable scraps (V), fish processing waste (F) and newspaper (N) or onion peels (O) were determined by applying the simplex-centroid mixture design method to achieve the desired initial moisture content and carbon-to-nitrogen (CN) ratio for effective composting process. The best mixture was at 48.5% V, 17.7% F and 33.7% N for blends with newspaper while for blends with onion peels, the mixture proportion was 44.0% V, 19.7% F and 36.2% O. The predicted responses from these mixture proportions fall in the acceptable limits of moisture content of 50% to 65% and CN ratio of 20-40 and were also validated experimentally. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. 3,5-Bis(4-meth-oxy-phen-yl)-1-phenyl-4,5-dihydro-1H-pyrazole.

    Science.gov (United States)

    Baktır, Zeliha; Akkurt, Mehmet; Samshuddin, S; Narayana, B; Yathirajan, H S

    2011-01-12

    In the title compound, C(23)H(22)N(2)O(2), the central pyrazole ring is nearly planar (r.m.s. deviation = 0.046 Å) and it makes a dihedral angle of 18.5 (2)° with the phenyl ring. The dihedral angles between the phenyl and the two meth-oxy-substituted phenyl rings are 26.2 (2) and 80.6 (2)°. The crystal structure is stabilized by C-H⋯π stacking inter-actions and weak π-π inter-actions [centriod-centroid distance = 3.891 (2) Å].

  3. N-[5-Methyl-2-(2-nitro-phen-yl)-4-oxo-1,3-thia-zolidin-3-yl]pyridine-3-carboxamide monohydrate.

    Science.gov (United States)

    Akkurt, Mehmet; Celik, Ismail; Demir, Hale; Ozkırımlı, Sumru; Büyükgüngör, Orhan

    2011-01-08

    In the title compound, C(16)H(14)N(4)O(4)S·H(2)O, the benzene and pyridine rings make a dihedral angle of 85.8 (1)°. Both enanti-omers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C(5) of the thia-zolidine ring) were therefore refined with common site-occupation factors of 0.531 (9) and 0.469 (9), respectively, for each stereoisomer. In the crystal, inter-molecular N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds link the mol-ecules, forming a three-dimensional supra-molecular network. The crystal structure further shows π-π stacking inter-actions [centroid-centroid distance = 3.5063 (13) Å] between the pyridine rings.

  4. Depth to the bottom of magnetic sources (DBMS) from aeromagnetic data of Central India using modified centroid method for fractal distribution of sources

    Science.gov (United States)

    Bansal, A. R.; Anand, S. P.; Rajaram, Mita; Rao, V. K.; Dimri, V. P.

    2013-09-01

    The depth to the bottom of the magnetic sources (DBMS) has been estimated from the aeromagnetic data of Central India. The conventional centroid method of DBMS estimation assumes random uniform uncorrelated distribution of sources and to overcome this limitation a modified centroid method based on scaling distribution has been proposed. Shallower values of the DBMS are found for the south western region. The DBMS values are found as low as 22 km in the south west Deccan trap covered regions and as deep as 43 km in the Chhattisgarh Basin. In most of the places DBMS are much shallower than the Moho depth, earlier found from the seismic study and may be representing the thermal/compositional/petrological boundaries. The large variation in the DBMS indicates the complex nature of the Indian crust.

  5. 3-Chloro-4-methyl­quinolin-2(1H)-one

    Science.gov (United States)

    Kassem, Mohamed G.; Ghabbour, Hazem A.; Abdel-Aziz, Hatem A.; Fun, Hoong-Kun; Ooi, Chin Wei

    2012-01-01

    The title compound, C10H8ClNO, is almost planar (r.m.s. deviation for the 13 non-H atoms = 0.023 Å). In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(8) rings. Weak aromatic π–π stacking inter­actions [centroid–centroid distance = 3.7622 (12) Å] also occur. PMID:22589913

  6. A walk-free centroid method for lifetime measurements with pulsed beams

    International Nuclear Information System (INIS)

    Julin, R.; Kantele, J.; Luontama, M.; Passoja, A.; Poikolainen, T.

    1977-09-01

    A delayed-coincidence lifetime measurement method based on a comparison of walk-free centroids of time spectra is presented. The time is measured between the cyclotron RF signal and the pulse from a plastic scintillation detector followed by a fixed energy selection. The events to be time-analyzed are selected from the associated charge-particle spectrum of a silicon detector which is operated in coincidence with the scintillator, i.e., independently of the formation of the signal containing the time information. With this technique, with the micropulse FWHM of typically 500 to 700 ps, half-lives down to the 10 ps region can be measured. The following half-lives are obtained with the new method: 160+-6 ps for the 2032 keV level in 209 Pb; 45+-10 ps and 160+-20 ps for the 1756.8 keV (0 2 + ) and 2027.3 keV (0 3 + ) levels in 116 Sn, respectively. (author)

  7. 3,5-Bis(4-meth­oxy­phen­yl)-1-phenyl-4,5-dihydro-1H-pyrazole

    Science.gov (United States)

    Baktır, Zeliha; Akkurt, Mehmet; Samshuddin, S.; Narayana, B.; Yathirajan, H. S.

    2011-01-01

    In the title compound, C23H22N2O2, the central pyrazole ring is nearly planar (r.m.s. deviation = 0.046 Å) and it makes a dihedral angle of 18.5 (2)° with the phenyl ring. The dihedral angles between the phenyl and the two meth­oxy-substituted phenyl rings are 26.2 (2) and 80.6 (2)°. The crystal structure is stabilized by C—H⋯π stacking inter­actions and weak π–π inter­actions [centriod–centroid distance = 3.891 (2) Å]. PMID:21523013

  8. 4-Fluoro-N-methyl-N-(1,2,3,4-tetra-hydro-carbazol-3-yl)benzene-sulfonamide

    DEFF Research Database (Denmark)

    Rasmussen, Kaspar Gothardt; Ulven, Trond; Bond, Andrew D

    2009-01-01

    into layers containing the carbazole units and fluoro-phenyl rings in alternate (200) planes. The carbazole units form centrosymmetric face-to-face inter-actions [inter-planar separation = 4.06 (1) Å] and edge-to-face inter-actions in which the N-H group is directed towards an adjacent carbazole face......, with a shortest H⋯C contact of 2.53 Å. The fluoro-phenyl rings form face-to-face contacts with an approximate inter-planar separation of 3.75 Å and a centroid-centroid distance of 4.73 (1) Å....

  9. (2RS)-2-(2,4-Difluoro-phen-yl)-1-[(4-iodo-benz-yl)(meth-yl)amino]-3-(1H-1,2,4-tri-azol-1-yl)propan-2-ol.

    Science.gov (United States)

    Xiong, Hui-Ping; Gao, Shou-Hong; Li, Chun-Tong; Wu, Zhi-Jun

    2012-08-01

    IN THE TITLE COMPOUND (COMMON NAME: iodiconazole), C(19)H(19)F(2)IN(4)O, there is an intra-molecular O-H⋯N hydrogen bond and mol-ecules are linked by weak inter-actions only, namely C-H⋯N, C-H⋯O and C-H⋯F hydrogen bonds, and π-electron ring-π-electron ring inter-actions between the triazole rings with centroid-centroid distances of 3.725 (3) Å.

  10. Acquisition and Initial Analysis of H+- and H--Beam Centroid Jitter at LANSCE

    Science.gov (United States)

    Gilpatrick, J. D.; Bitteker, L.; Gulley, M. S.; Kerstiens, D.; Oothoudt, M.; Pillai, C.; Power, J.; Shelley, F.

    2006-11-01

    During the 2005 Los Alamos Neutron Science Center (LANSCE) beam runs, beam current and centroid-jitter data were observed, acquired, analyzed, and documented for both the LANSCE H+ and H- beams. These data were acquired using three beam position monitors (BPMs) from the 100-MeV Isotope Production Facility (IPF) beam line and three BPMs from the Switchyard transport line at the end of the LANSCE 800-MeV linac. The two types of data acquired, intermacropulse and intramacropulse, were analyzed for statistical and frequency characteristics as well as various other correlations including comparing their phase-space like characteristics in a coordinate system of transverse angle versus transverse position. This paper will briefly describe the measurements required to acquire these data, the initial analysis of these jitter data, and some interesting dilemmas these data presented.

  11. Crystal structure of 2,5-di-methyl-anilinium salicylate.

    Science.gov (United States)

    Mani, A; Kumar, P Praveen; Chakkaravarthi, G

    2015-09-01

    The title mol-ecular salt, C8H12N(+)·C7H5O3 (-) arose from the proton-transfer reaction between 2,5-xylidine and salicylic acid. In the anion, the dihedral angle between the planes of the aromatic ring and the -CO2 (-) group is 11.08 (8)°; this near planarity is consolidated by an intra-molecular O-H⋯O hydrogen bond. In the crystal, the components are connected by N-H⋯O hydrogen bonds, with all three O atoms in the anion acting as acceptors; the result is a [100] chain. The structure also features weak C-H⋯O bonds and aromatic π-π stacking [centroid-to-centroid distance = 3.7416 (10) Å] inter-actions, which lead to a three-dimensional network.

  12. Collective centroid oscillations as an emittance preservation diagnostic in linear collider linacs

    International Nuclear Information System (INIS)

    Adolphsen, C.E.; Bane, K.L.F.; Spence, W.L.; Woodley, M.D.

    1997-08-01

    Transverse bunch centroid oscillations, induced at operating beam currents at which transverse wakefields are substantial, and observed at Beam Position Monitors, are sensitive to the actual magnetic focusing, energy gain, and rf phase profiles in a linac, and are insensitive to misalignments and jitter sources. In the pulse stealing set-up implemented at the SLC, they thus allow the frequent monitoring of the stability of the in-place emittance growth inhibiting or mitigating measures--primarily the energy scaled magnetic lattice and the rf phases necessary for BNS damping--independent of the actual emittance growth as driven by misalignments and jitter. The authors have developed a physically based analysis technique to meaningfully reduce the data. Oscillation beta-beating is a primary indicator of beam energy errors; shifts in the invariant amplitude reflect differential internal motion along the longitudinally extended bunch and thus are a sensitive indicator of the real rf phases in the machine; shifts in betatron phase advance contain corroborative information sensitive to both effects

  13. Simulation of plume rise: Study the effect of stably stratified turbulence layer on the rise of a buoyant plume from a continuous source by observing the plume centroid

    Science.gov (United States)

    Bhimireddy, Sudheer Reddy; Bhaganagar, Kiran

    2016-11-01

    Buoyant plumes are common in atmosphere when there exists a difference in temperature or density between the source and its ambience. In a stratified environment, plume rise happens until the buoyancy variation exists between the plume and ambience. In a calm no wind ambience, this plume rise is purely vertical and the entrainment happens because of the relative motion of the plume with ambience and also ambient turbulence. In this study, a plume centroid is defined as the plume mass center and is calculated from the kinematic equation which relates the rate of change of centroids position to the plume rise velocity. Parameters needed to describe the plume are considered as the plume radius, plumes vertical velocity and local buoyancy of the plume. The plume rise velocity is calculated by the mass, momentum and heat conservation equations in their differential form. Our study focuses on the entrainment velocity, as it depicts the extent of plume growth. This entrainment velocity is made up as sum of fractions of plume's relative velocity and ambient turbulence. From the results, we studied the effect of turbulence on the plume growth by observing the variation in the plume radius at different heights and the centroid height reached before loosing its buoyancy.

  14. Peak-locking centroid bias in Shack-Hartmann wavefront sensing

    Science.gov (United States)

    Anugu, Narsireddy; Garcia, Paulo J. V.; Correia, Carlos M.

    2018-05-01

    Shack-Hartmann wavefront sensing relies on accurate spot centre measurement. Several algorithms were developed with this aim, mostly focused on precision, i.e. minimizing random errors. In the solar and extended scene community, the importance of the accuracy (bias error due to peak-locking, quantization, or sampling) of the centroid determination was identified and solutions proposed. But these solutions only allow partial bias corrections. To date, no systematic study of the bias error was conducted. This article bridges the gap by quantifying the bias error for different correlation peak-finding algorithms and types of sub-aperture images and by proposing a practical solution to minimize its effects. Four classes of sub-aperture images (point source, elongated laser guide star, crowded field, and solar extended scene) together with five types of peak-finding algorithms (1D parabola, the centre of gravity, Gaussian, 2D quadratic polynomial, and pyramid) are considered, in a variety of signal-to-noise conditions. The best performing peak-finding algorithm depends on the sub-aperture image type, but none is satisfactory to both bias and random errors. A practical solution is proposed that relies on the antisymmetric response of the bias to the sub-pixel position of the true centre. The solution decreases the bias by a factor of ˜7 to values of ≲ 0.02 pix. The computational cost is typically twice of current cross-correlation algorithms.

  15. Observations of sensor bias dependent cluster centroid shifts in a prototype sensor for the LHCb Vertex Locator detector

    CERN Document Server

    Papadelis, Aras

    2006-01-01

    We present results from a recent beam test of a prototype sensor for the LHCb Vertex Locator detector, read out with the Beetle 1.3 front-end chip. We have studied the effect of the sensor bias voltage on the reconstructed cluster positions in a sensor placed in a 120GeV pion beam at a 10° incidence angle. We find an unexplained sysematic shift in the reconstructed cluster centroid when increasing the bias voltage on an already overdepleted sensor. The shift is independent of strip pitch and sensor thickness.

  16. Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

    Science.gov (United States)

    Hallo, Miroslav; Asano, Kimiyuki; Gallovič, František

    2017-09-01

    On April 16, 2016, Kumamoto prefecture in Kyushu region, Japan, was devastated by a shallow M JMA7.3 earthquake. The series of foreshocks started by M JMA6.5 foreshock 28 h before the mainshock. They have originated in Hinagu fault zone intersecting the mainshock Futagawa fault zone; hence, the tectonic background for this earthquake sequence is rather complex. Here we infer centroid moment tensors (CMTs) for 11 events with M JMA between 4.8 and 6.5, using strong motion records of the K-NET, KiK-net and F-net networks. We use upgraded Bayesian full-waveform inversion code ISOLA-ObsPy, which takes into account uncertainty of the velocity model. Such an approach allows us to reliably assess uncertainty of the CMT parameters including the centroid position. The solutions show significant systematic spatial and temporal variations throughout the sequence. Foreshocks are right-lateral steeply dipping strike-slip events connected to the NE-SW shear zone. Those located close to the intersection of the Hinagu and Futagawa fault zones are dipping slightly to ESE, while those in the southern area are dipping to WNW. Contrarily, aftershocks are mostly normal dip-slip events, being related to the N-S extensional tectonic regime. Most of the deviatoric moment tensors contain only minor CLVD component, which can be attributed to the velocity model uncertainty. Nevertheless, two of the CMTs involve a significant CLVD component, which may reflect complex rupture process. Decomposition of those moment tensors into two pure shear moment tensors suggests combined right-lateral strike-slip and normal dip-slip mechanisms, consistent with the tectonic settings of the intersection of the Hinagu and Futagawa fault zones.[Figure not available: see fulltext.

  17. 4-[(1E)-3-(2,6-Dichloro-3-fluoro-phen-yl)-3-oxoprop-1-en-1-yl]benzonitrile.

    Science.gov (United States)

    Praveen, Aletti S; Yathirajan, Hemmige S; Narayana, Badiadka; Gerber, Thomas; Hosten, Eric; Betz, Richard

    2012-05-01

    In the title mol-ecule, C(16)H(8)Cl(2)FNO, the benzene rings form a dihedral angle of 78.69 (8)°. The F atom is disordered over two positions in a 0.530 (3):0.470 (3) ratio. The crystal packing exhibits π-π inter-actions between dichloro-substituted rings [centroid-centroid distance = 3.6671 (10) Å] and weak inter-molecular C-H⋯F contacts.

  18. Power centroid radar and its rise from the universal cybernetics duality

    Science.gov (United States)

    Feria, Erlan H.

    2014-05-01

    Power centroid radar (PC-Radar) is a fast and powerful adaptive radar scheme that naturally surfaced from the recent discovery of the time-dual for information theory which has been named "latency theory." Latency theory itself was born from the universal cybernetics duality (UC-Duality), first identified in the late 1970s, that has also delivered a time dual for thermodynamics that has been named "lingerdynamics" and anchors an emerging lifespan theory for biological systems. In this paper the rise of PC-Radar from the UC-Duality is described. The development of PC-Radar, US patented, started with Defense Advanced Research Projects Agency (DARPA) funded research on knowledge-aided (KA) adaptive radar of the last decade. The outstanding signal to interference plus noise ratio (SINR) performance of PC-Radar under severely taxing environmental disturbances will be established. More specifically, it will be seen that the SINR performance of PC-Radar, either KA or knowledgeunaided (KU), approximates that of an optimum KA radar scheme. The explanation for this remarkable result is that PC-Radar inherently arises from the UC-Duality, which advances a "first principles" duality guidance theory for the derivation of synergistic storage-space/computational-time compression solutions. Real-world synthetic aperture radar (SAR) images will be used as prior-knowledge to illustrate these results.

  19. (Carbonato-κ(2)O,O')bis-(5,5'-dimethyl-2,2'-bipyridyl-κ(2)N,N')cobalt(III) bromide trihydrate.

    Science.gov (United States)

    Arun Kumar, Kannan; Meera, Parthsarathi; Amutha Selvi, Madhavan; Dayalan, Arunachalam

    2012-04-01

    In the title complex, [Co(CO(3))(C(12)H(12)N(2))(2)]Br·3H(2)O, the Co(III) cation has a distorted octa-hedral coordination environment. It is chelated by four N atoms of two different 5,5'-dimethyl-2,2'-bipyridyl (dmbpy) ligands in axial and equatorial positions, and by two O atoms of a carbonate anion completing the equatorial positions. Although the water mol-ecules are disordered and their H atoms were not located, there are typical O⋯O distances between 2.8 and 3.0 Å, indicating O-H⋯O hydrogen bonding. The crystal packing is consolidated by C-H⋯O and C-H⋯Br hydrogen bonds, as well as π-π stacking inter-actions between adjacent pyridine rings of the dmbpy ligands, with centroid-centroid distances of 3.694 (3) and 3.7053 (3) Å.

  20. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    CERN Document Server

    Ambrosi, R M; Hill, J; Cheruvu, C; Abbey, A F; Short, A D T

    2002-01-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Planck Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence ...

  1. Path integral centroid molecular dynamics simulations of semiinfinite slab and bulk liquid of para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Kenichi [Nara Women`s Univ., Nara (Japan). Dept. of Chemistry

    1998-10-01

    It has been unsuccessful to solve a set of time-dependent Schroedinger equations numerically for many-body quantum systems which involve, e.g., a number of hydrogen molecules, protons, and excess electrons at a low temperature, where quantum effect evidently appears. This undesirable situation is fatal for the investigation of real low-temperature chemical systems because they are essentially composed of many quantum degrees of freedom. However, if we use a new technique called `path integral centroid molecular dynamics (CMD) simulation` proposed by Cao and Voth in 1994, the real-time semi-classical dynamics of many degrees of freedom can be computed by utilizing the techniques already developed in the traditional classical molecular dynamics (MD) simulations. Therefore, the CMD simulation is expected to be very powerful tool for the quantum dynamics studies or real substances. (J.P.N.)

  2. Centroid based clustering of high throughput sequencing reads based on n-mer counts.

    Science.gov (United States)

    Solovyov, Alexander; Lipkin, W Ian

    2013-09-08

    Many problems in computational biology require alignment-free sequence comparisons. One of the common tasks involving sequence comparison is sequence clustering. Here we apply methods of alignment-free comparison (in particular, comparison using sequence composition) to the challenge of sequence clustering. We study several centroid based algorithms for clustering sequences based on word counts. Study of their performance shows that using k-means algorithm with or without the data whitening is efficient from the computational point of view. A higher clustering accuracy can be achieved using the soft expectation maximization method, whereby each sequence is attributed to each cluster with a specific probability. We implement an open source tool for alignment-free clustering. It is publicly available from github: https://github.com/luscinius/afcluster. We show the utility of alignment-free sequence clustering for high throughput sequencing analysis despite its limitations. In particular, it allows one to perform assembly with reduced resources and a minimal loss of quality. The major factor affecting performance of alignment-free read clustering is the length of the read.

  3. Comparison of pure and 'Latinized' centroidal Voronoi tessellation against various other statistical sampling methods

    International Nuclear Information System (INIS)

    Romero, Vicente J.; Burkardt, John V.; Gunzburger, Max D.; Peterson, Janet S.

    2006-01-01

    A recently developed centroidal Voronoi tessellation (CVT) sampling method is investigated here to assess its suitability for use in statistical sampling applications. CVT efficiently generates a highly uniform distribution of sample points over arbitrarily shaped M-dimensional parameter spaces. On several 2-D test problems CVT has recently been found to provide exceedingly effective and efficient point distributions for response surface generation. Additionally, for statistical function integration and estimation of response statistics associated with uniformly distributed random-variable inputs (uncorrelated), CVT has been found in initial investigations to provide superior points sets when compared against latin-hypercube and simple-random Monte Carlo methods and Halton and Hammersley quasi-random sequence methods. In this paper, the performance of all these sampling methods and a new variant ('Latinized' CVT) are further compared for non-uniform input distributions. Specifically, given uncorrelated normal inputs in a 2-D test problem, statistical sampling efficiencies are compared for resolving various statistics of response: mean, variance, and exceedence probabilities

  4. 3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

    Science.gov (United States)

    Ranjith, S.; SubbiahPandi, A.; Suresh, A. D.; Pitchumani, K.

    2011-01-01

    In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]. PMID:21837144

  5. Ranking Fuzzy Numbers with a Distance Method using Circumcenter of Centroids and an Index of Modality

    Directory of Open Access Journals (Sweden)

    P. Phani Bushan Rao

    2011-01-01

    Full Text Available Ranking fuzzy numbers are an important aspect of decision making in a fuzzy environment. Since their inception in 1965, many authors have proposed different methods for ranking fuzzy numbers. However, there is no method which gives a satisfactory result to all situations. Most of the methods proposed so far are nondiscriminating and counterintuitive. This paper proposes a new method for ranking fuzzy numbers based on the Circumcenter of Centroids and uses an index of optimism to reflect the decision maker's optimistic attitude and also an index of modality that represents the neutrality of the decision maker. This method ranks various types of fuzzy numbers which include normal, generalized trapezoidal, and triangular fuzzy numbers along with crisp numbers with the particularity that crisp numbers are to be considered particular cases of fuzzy numbers.

  6. Centroid Localization of Uncooperative Nodes in Wireless Networks Using a Relative Span Weighting Method

    Directory of Open Access Journals (Sweden)

    Christine Laurendeau

    2010-01-01

    Full Text Available Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target is a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receiver's coordinates based on the message's relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

  7. Neutron radiography with sub-15 {mu}m resolution through event centroiding

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, Anton S., E-mail: ast@ssl.berkeley.edu [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); McPhate, Jason B.; Vallerga, John V.; Siegmund, Oswald H.W. [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); Bruce Feller, W. [NOVA Scientific, Inc. 10 Picker Road, Sturbridge, MA 01566 (United States); Lehmann, Eberhard; Kaestner, Anders; Boillat, Pierre; Panzner, Tobias; Filges, Uwe [Spallation Neutron Source Division, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2012-10-01

    Conversion of thermal and cold neutrons into a strong {approx}1 ns electron pulse with an absolute neutron detection efficiency as high as 50-70% makes detectors with {sup 10}B-doped Microchannel Plates (MCPs) very attractive for neutron radiography and microtomography applications. The subsequent signal amplification preserves the location of the event within the MCP pore (typically 6-10 {mu}m in diameter), providing the possibility to perform neutron counting with high spatial resolution. Different event centroiding techniques of the charge landing on a patterned anode enable accurate reconstruction of the neutron position, provided the charge footprints do not overlap within the time required for event processing. The new fast 2 Multiplication-Sign 2 Timepix readout with >1.2 kHz frame rates provides the unique possibility to detect neutrons with sub-15 {mu}m resolution at several MHz/cm{sup 2} counting rates. The results of high resolution neutron radiography experiments presented in this paper, demonstrate the sub-15 {mu}m resolution capability of our detection system. The high degree of collimation and cold spectrum of ICON and BOA beamlines combined with the high spatial resolution and detection efficiency of MCP-Timepix detectors are crucial for high contrast neutron radiography and microtomography with high spatial resolution. The next generation of Timepix electronics with sparsified readout should enable counting rates in excess of 10{sup 7} n/cm{sup 2}/s taking full advantage of high beam intensity of present brightest neutron imaging facilities.

  8. [2,3,7,8,13,14,17,18-Octa-kis(ethyl-sulfan-yl)-5,10,15,20-porphyrazinato]zinc(II).

    Science.gov (United States)

    Akkurt, Mehmet; Coşkun, Naciye Yılmaz; Kılıçaslan, Fatma Aytan; Yalçın, Sabiha Manav; Büyükgüngör, Orhan; Gül, Ahmet

    2010-07-24

    In the title compound, [Zn(C(32)H(40)N(8)S(8))], the Zn(II) ion is coordinated by four N atoms in a slightly distorted square-planar environment. In addition, there is a Zn⋯S contact involving a symmetry-related S atom which, when considered, forms a pseudo-square-pyramidal coordination with respect to the Zn(II) ion. Three of the ethyl groups are disordered over two sites with occupancy ratios of 0.841 (10):0.159 (10), 0.802 (10):0.198 (10) and 0.457 (13):0.543 (13). Weak intra-molecular C-H⋯N and C-H⋯S inter-actions contribute to the stability of the mol-ecular conformation. Inter-molecular C-H⋯S contacts, weak C-H⋯π inter-actions and π-π stacking inter-actions [centroid-centriod distances = 3.832 (4) and 3.850 (5) Å] contribute to the stabilization of the crystal structure.

  9. Dominant π⋅⋅⋅π interaction in the self assemblies of 4 ...

    Indian Academy of Sciences (India)

    Administrator

    The centroid to centroid distance is 3⋅78 Å and the perpendicular distance between the offset stacked rings is 3⋅42 Å with displacement angle. 19. 21° and lateral displace- ment 1⋅61 Å. The offset stacked molecules form a zig–zag pattern through the π⋅⋅⋅π offset stacks. (3⋅78 Å) and stacked molecules. A similar array ...

  10. The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Régis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Mach, H. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Simpson, G.S. [Laboratoire de Physique Subatomique et de Cosmologie Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Jolie, J.; Pascovici, G.; Saed-Samii, N.; Warr, N. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Bruce, A. [School of Computing, Engineering and Mathematics, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Degenkolb, J. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Fraile, L.M. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Fransen, C. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Ghita, D.G. [Horia Hulubei National Institute for Physics and Nuclear Engineering, 77125 Bucharest (Romania); and others

    2013-10-21

    A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via γ–γ coincidences using an array equipped with N∈N equally shaped very fast high-resolution LaBr{sub 3}(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent “start” and “stop” time spectra obtained by a superposition of the N(N−1)γ–γ time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific γ–γ cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean γ–γ time-walk characteristics can be determined for 40keV

  11. Crystal structure of bis-[N-(2-hy-droxy-eth-yl)-N-methyl-dithio-carbamato-κ2S,S'](pyridine)-zinc(II) pyridine monosolvate and its N-ethyl analogue.

    Science.gov (United States)

    Poplaukhin, Pavel; Tiekink, Edward R T

    2017-07-01

    The common structural feature of the title compounds, [Zn(C 4 H 8 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (I) and [Zn(C 5 H 10 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (II), which differ by having di-thio-carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each Zn II atom by two non-symmetrically chelating di-thio-carbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine mol-ecule is connected to the Zn-containing mol-ecule via a (hy-droxy)O-H⋯N(pyridine) hydrogen bond. The resulting NS 4 coordination geometry is closer to a square-pyramid than a trigonal bipyramid in the case of (I), but almost inter-mediate between the two extremes in (II). The mol-ecular packing features (hy-droxy)O-H⋯O(hy-droxy) hydrogen bonds, leading to supra-molecular chains with a zigzag arrangement along [10-1] (I) or a helical arrangement along [010] (II). In (I), π-π [inter-centroid distances = 3.4738 (10) and 3.4848 (10) Å] between coordinating and non-coordinating pyridine mol-ecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π-π contacts occur between centrosymmetrically related pairs of coordinating pyridine mol-ecules [inter-centroid separation = 3.9815 (14) Å]. Further inter-actions, including C-H⋯π(chelate) inter-actions in (I), lead to a three-dimensional architecture in each case.

  12. Spectral and temporal cues for perception of material and action categories in impacted sound sources

    DEFF Research Database (Denmark)

    Hjortkjær, Jens; McAdams, Stephen

    2016-01-01

    In two experiments, similarity ratings and categorization performance with recorded impact sounds representing three material categories (wood, metal, glass) being manipulated by three different categories of action (drop, strike, rattle) were examined. Previous research focusing on single impact...... correlated with the pattern of confusion in categorization judgments. Listeners tended to confuse materials with similar spectral centroids, and actions with similar temporal centroids and onset densities. To confirm the influence of these different features, spectral cues were removed by applying...

  13. (Carbonato-κ2 O,O′)bis­(1,10-phenan­throline-κ2 N,N′)cobalt(III) nitrate monohydrate

    Science.gov (United States)

    Andaç, Ömer; Yolcu, Zuhal; Büyükgüngör, Orhan

    2010-01-01

    The crystal structure of the title compound, [Co(CO3)(C12H8N2)2]NO3·H2O, consists of CoIII complex cations, nitrate anions and uncoordinated water mol­ecules. The CoIII cation is chelated by a carbonate anion and two phenanthroline ligands in a distorted octa­hedral coordination geometry. A three-dimensional supra­molecular structure is formed by O—H⋯O and C—H⋯O hydrogen bonding, C—H⋯π and aromatic π–π stacking [centroid–centroid distance = 3.995 (1)Å] inter­actions. PMID:21579944

  14. [4,6-Dimethyl­pyrimidine-2(1H)-thione-κS]iodidobis(triphenyl­phosphane-κP)copper(I)

    Science.gov (United States)

    Pakawatchai, Chaveng; Wattanakanjana, Yupa; Choto, Patcharanan; Nimthong, Ruthairat

    2012-01-01

    In the mononuclear title complex, [CuI(C6H8N2S)(C18H15P)2], the CuI ion is in a slightly distorted tetra­hedral coordination geometry formed by two P atoms from two triphenyl­phosphane ligands, one S atom from a 4,6-dimethyl­pyrimidine-2(1H)-thione ligand and one iodide ion. There is an intra­molecular N—H⋯I hydrogen bond. In the crystal, π–π stacking inter­actions [centroid–centroid distance = 3.594 (1) Å] are observed. PMID:22719327

  15. Detection of a surface breaking crack by using the centroid variations of laser ultrasonic spectrums

    International Nuclear Information System (INIS)

    Park, Seung Kyu; Baik, Sung Hoon; Lim, Chang Hwan; Joo, Young Sang; Jung, Hyun Kyu; Cha, Hyung Ki; Kang, Young June

    2006-01-01

    A laser ultrasonic system is a non-contact inspection device with a wide-band spectrum and a high spatial resolution. It provides absolute measurements of the moving distance and it can be applied to hard-to-access locations including curved or rough surfaces like in a nuclear power plant. In this paper, we have investigated the detection methods of the depth of a surface-breaking crack by using the surface wave of a laser ultrasound. The filtering function of a surface-breaking crack is a kind of a low-pass filter. The higher frequency components are more highly decreased in proportion to the crack depth. Also, the center frequency value of each ultrasound spectrum is decreased in proportion to the crack depth. We extracted the depth information of a surface-breaking crack by observing the centroid variation of the frequency spectrum. We describe the experimental results to detect the crack depth information by using the peak-to-valley values in the time domain and the center frequency values in the frequency domain.

  16. Centroid moment tensor catalogue using a 3-D continental scale Earth model: Application to earthquakes in Papua New Guinea and the Solomon Islands

    Science.gov (United States)

    Hejrani, Babak; Tkalčić, Hrvoje; Fichtner, Andreas

    2017-07-01

    Although both earthquake mechanism and 3-D Earth structure contribute to the seismic wavefield, the latter is usually assumed to be layered in source studies, which may limit the quality of the source estimate. To overcome this limitation, we implement a method that takes advantage of a 3-D heterogeneous Earth model, recently developed for the Australasian region. We calculate centroid moment tensors (CMTs) for earthquakes in Papua New Guinea (PNG) and the Solomon Islands. Our method is based on a library of Green's functions for each source-station pair for selected Geoscience Australia and Global Seismic Network stations in the region, and distributed on a 3-D grid covering the seismicity down to 50 km depth. For the calculation of Green's functions, we utilize a spectral-element method for the solution of the seismic wave equation. Seismic moment tensors were calculated using least squares inversion, and the 3-D location of the centroid is found by grid search. Through several synthetic tests, we confirm a trade-off between the location and the correct input moment tensor components when using a 1-D Earth model to invert synthetics produced in a 3-D heterogeneous Earth. Our CMT catalogue for PNG in comparison to the global CMT shows a meaningful increase in the double-couple percentage (up to 70%). Another significant difference that we observe is in the mechanism of events with depth shallower then 15 km and Mw region.

  17. Crystal structure of bis-(μ-3-nitro-benzoato)-κ3O,O':O;κ3O:O,O'-bis-[bis-(3-cyano-pyridine-κN1)(3-nitro-benzoato-κ2O,O')cadmium].

    Science.gov (United States)

    Hökelek, Tuncer; Akduran, Nurcan; Özen, Azer; Uğurlu, Güventürk; Necefoğlu, Hacali

    2017-03-01

    The asymmetric unit of the title compound, [Cd 2 (C 7 H 4 NO 4 ) 4 (C 6 H 4 N 2 ) 4 ], contains one Cd II atom, two 3-nitro-benzoate (NB) anions and two 3-cyano-pyridine (CPy) ligands. The two CPy ligands act as monodentate N(pyridine)-bonding ligands, while the two NB anions act as bidentate ligands through the carboxyl-ate O atoms. The centrosymmetric dinuclear complex is generated by application of inversion symmetry, whereby the Cd II atoms are bridged by the carboxyl-ate O atoms of two symmetry-related NB anions, thus completing the distorted N 2 O 5 penta-gonal-bipyramidal coordination sphere of each Cd II atom. The benzene and pyridine rings are oriented at dihedral angles of 10.02 (7) and 5.76 (9)°, respectively. In the crystal, C-H⋯N hydrogen bonds link the mol-ecules, enclosing R 2 2 (26) ring motifs, in which they are further linked via C-H⋯O hydrogen bonds, resulting in a three-dimensional network. In addition, π-π stacking inter-actions between parallel benzene rings and between parallel pyridine rings of adjacent mol-ecules [shortest centroid-to-centroid distances = 3.885 (1) and 3.712 (1) Å, respectively], as well as a weak C-H⋯π inter-action, may further stabilize the crystal structure.

  18. Decadal Western Pacific Warm Pool Variability: A Centroid and Heat Content Study.

    Science.gov (United States)

    Kidwell, Autumn; Han, Lu; Jo, Young-Heon; Yan, Xiao-Hai

    2017-10-13

    We examine several characteristics of the Western Pacific Warm Pool (WP) in the past thirty years of mixed interannual variability and climate change. Our study presents the three-dimensional WP centroid (WPC) movement, WP heat content anomaly (HC) and WP volume (WPV) on interannual to decadal time scales. We show the statistically significant correlation between each parameter's interannual anomaly and the NINO 3, NINO 3.4, NINO 4, SOI, and PDO indices. The longitudinal component of the WPC is most strongly correlated with NINO 4 (R = 0.78). The depth component of the WPC has the highest correlation (R = -0.6) with NINO3.4. The WPV and NINO4 have an R-Value of -0.65. HC has the highest correlation with NINO3.4 (R = -0.52). During the study period of 1982-2014, the non-linear trends, derived from ensemble empirical mode decomposition (EEMD), show that the WPV, WP depth and HC have all increased. The WPV has increased by 14% since 1982 and the HC has increased from -1 × 10 8  J/m 2 in 1993 to 10 × 10 8  J/m 2 in 2014. While the largest variances in the latitudinal and longitudinal WPC locations are associated with annual and seasonal timescales, the largest variances in the WPV and HC are due to the multi-decadal non-linear trend.

  19. Crystal structure of di-bromo-meth-oxy-seselin (DBMS), a photobiologically active pyran-ocoumarin.

    Science.gov (United States)

    Bauri, A K; Foro, Sabine; Rahman, A F M M

    2017-05-01

    The title compound, C 15 H 14 Br 2 O 4 [systematic name: rac -(9 S ,10 R )-3,9-dibromo-10-methoxy-8,8-dimethyl-9,10-dihydropyrano[2,3- h ]chromen-2(8 H )-one], is a pyran-ocoumarin derivative formed by the bromination of seselin, which is a naturally occurring angular pyran-ocoumarin isolated from the Indian herb Trachyspermum stictocarpum . In the mol-ecule, the benzo-pyran ring system is essentially planar, with a maximum deviation of 0.044 (2) Å for the O atom. The di-hydro-pyran ring is in a half-chair conformation and the four essentially planar atoms of this ring form a dihedral angle of 4.6 (2)° with the benzo-pyran ring system. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming chains propagating along [010]. In addition, π-π stacking inter-actions, with centroid-centroid distances of 3.902 (2) and 3.908 (2) Å, link the hydrogen-bonded chains into layers parallel to (001).

  20. Model Independent Analysis of Beam Centroid Dynamics in Accelerators

    International Nuclear Information System (INIS)

    Wang, Chun-xi

    2003-01-01

    Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map

  1. Model Independent Analysis of Beam Centroid Dynamics in Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun-xi

    2003-04-21

    Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map

  2. Bayesian ISOLA: new tool for automated centroid moment tensor inversion

    Science.gov (United States)

    Vackář, Jiří; Burjánek, Jan; Gallovič, František; Zahradník, Jiří; Clinton, John

    2017-04-01

    Focal mechanisms are important for understanding seismotectonics of a region, and they serve as a basic input for seismic hazard assessment. Usually, the point source approximation and the moment tensor (MT) are used. We have developed a new, fully automated tool for the centroid moment tensor (CMT) inversion in a Bayesian framework. It includes automated data retrieval, data selection where station components with various instrumental disturbances and high signal-to-noise are rejected, and full-waveform inversion in a space-time grid around a provided hypocenter. The method is innovative in the following aspects: (i) The CMT inversion is fully automated, no user interaction is required, although the details of the process can be visually inspected latter on many figures which are automatically plotted.(ii) The automated process includes detection of disturbances based on MouseTrap code, so disturbed recordings do not affect inversion.(iii) A data covariance matrix calculated from pre-event noise yields an automated weighting of the station recordings according to their noise levels and also serves as an automated frequency filter suppressing noisy frequencies.(iv) Bayesian approach is used, so not only the best solution is obtained, but also the posterior probability density function.(v) A space-time grid search effectively combined with the least-squares inversion of moment tensor components speeds up the inversion and allows to obtain more accurate results compared to stochastic methods. The method has been tested on synthetic and observed data. It has been tested by comparison with manually processed moment tensors of all events greater than M≥3 in the Swiss catalogue over 16 years using data available at the Swiss data center (http://arclink.ethz.ch). The quality of the results of the presented automated process is comparable with careful manual processing of data. The software package programmed in Python has been designed to be as versatile as possible in

  3. catena-Poly[bis(1,3-benzo-thia-zol-3-ium) [[di-chlorido-anti-monate(III)]-di-μ-chlorido-μ-oxido-[chlorido-anti-monate(III)]-μ-chlorido

    Science.gov (United States)

    Chebout, Oussama; Boudraa, Mhamed; Bouacida, Sofiane; Merazig, Hocine; Boudaren, Chaouki

    2016-02-01

    The title compound, {(C7H6NS)2[Sb2Cl6O]} n , contains two benzo-thia-zolidium cations and one tri-μ-chlorido-tri-chlorido-μ-oxido-di-anti-monate(III) anion. The structure of the inorganic cation may be described as as being built up from two polyhedra, i.e. a square-pyramidal SbCl4O and a distorted octa-hedral SbOCl5 unit, sharing a common face (comprising the O atom and two Cl atoms). The two benzo-thia-zole cations are quasi-planar and subtend a dihedral angle of 19.93 (5)°. The crystal packing can be described by alternating (100) layers and [001] chains of the organic cations and inorganic anions connected through an extensive three-dimensional network of N-H⋯Cl, C-H⋯O and C-H⋯Cl hydrogen bonds. This is consolidated by slipped π-π stacking, with centroid-to-centroid distances between the benzo-thia-zole rings of 3.7111 (18)-3.8452 (16) Å. These inter-actions link the mol-ecules within the layers and also link the layers together and reinforce the cohesion of the ionic structure.

  4. Quick regional centroid moment tensor solutions for the Emilia 2012 (northern Italy seismic sequence

    Directory of Open Access Journals (Sweden)

    Silvia Pondrelli

    2012-10-01

    Full Text Available In May 2012, a seismic sequence struck the Emilia region (northern Italy. The mainshock, of Ml 5.9, occurred on May 20, 2012, at 02:03 UTC. This was preceded by a smaller Ml 4.1 foreshock some hours before (23:13 UTC on May 19, 2012 and followed by more than 2,500 earthquakes in the magnitude range from Ml 0.7 to 5.2. In addition, on May 29, 2012, three further strong earthquakes occurred, all with magnitude Ml ≥5.2: a Ml 5.8 earthquake in the morning (07:00 UTC, followed by two events within just 5 min of each other, one at 10:55 UTC (Ml 5.3 and the second at 11:00 UTC (Ml 5.2. For all of the Ml ≥4.0 earthquakes in Italy and for all of the Ml ≥4.5 in the Mediterranean area, an automatic procedure for the computation of a regional centroid moment tensor (RCMT is triggered by an email alert. Within 1 h of the event, a manually revised quick RCMT (QRCMT can be published on the website if the solution is considered stable. In particular, for the Emilia seismic sequence, 13 QRCMTs were determined and for three of them, those with M >5.5, the automatically computed QRCMTs fitted the criteria for publication without manual revision. Using this seismic sequence as a test, we can then identify the magnitude threshold for automatic publication of our QRCMTs.

  5. Crystal structure of a second triclinic polymorph of 2-methylpyridinium picrate

    Directory of Open Access Journals (Sweden)

    Jeganathan Gomathi

    2015-11-01

    Full Text Available The title molecular salt, C6H8N+·C6H2N3O7− (systematic name: 2-methylpyridinium 2,4,6-trinitrophenolate, crystallizes with two cations and two anions in the asymmetric unit. In the crystal, the cations are linked to the anions via bifurcated N—H...(O,O hydrogen bonds, generating R12(6 graph-set motifs. Numerous C—H...O hydrogen bonds are observed between these cation–anion pairs, which result in a three-dimensional network. In addition, weak aromatic π–π stacking between the 2-methylpyridinium rings [inter-centroid distance = 3.8334 (19 Å] and very weak stacking [inter-centroid distance = 4.0281 (16 Å] between inversion-related pairs of picrate anions is observed. The title salt is a second triclinic polymorph of the structure (also with Z′ = 2 reported earlier [Anita et al. (2006. Acta Cryst. C62, o567–o570; Chan et al. (2014. CrystEngComm, 16, 4508–4538]. In the title compound, the cations and anions display a chequerboard arrangement when viewed down [100], whereas in the first polymorph, (010 layers of alternating cations and anions are apparent in a [100] view. It is interesting that the unit-cell lengths are almost identical for the two polymorphs, although the inter-axial angles are quite different.

  6. 3-Phenyl-6-(2-pyridyl-1,2,4,5-tetrazine

    Directory of Open Access Journals (Sweden)

    Daniel Chartrand

    2008-01-01

    Full Text Available The title compound, C13H9N5, is the first asymmetric diaryl-1,2,4,5-tetrazine to be crystallographically characterized. We have been interested in this motif for incorporation into supramolecular assemblies based on coordination chemistry. The solid state structure shows a centrosymmetric molecule, forcing a positional disorder of the terminal phenyl and pyridyl rings. The molecule is completely planar, unusual for aromatic rings with N atoms in adjacent ortho positions. The stacking observed is very common in diaryltetrazines and is dominated by π stacking [centroid-to-centroid distance between the tetrazine ring and the aromatic ring of an adjacent molecule is 3.6 Å, perpendicular (centroid-to-plane distance of about 3.3 Å].

  7. Cellular Phone Towers, Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected to orthophotography. Probably includes towers other than cell towers (uncertain). Not published., Published in 2003, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2003. Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected...

  8. 2,3-Di­phenyl­male­imide 1-methyl­pyrrol­idin-2-one monosolvate

    Science.gov (United States)

    Bulatov, Evgeny; Boyarskaya, Dina; Chulkova, Tatiana; Haukka, Matti

    2014-01-01

    In the title compound, C16H11NO2·C5H9NO, the dihedral angles between the male­imide and phenyl rings are 34.7 (2) and 64.8 (2)°. In the crystal, the 2,3-di­phenyl­male­imide and 1-methyl­pyrrolidin-2-one mol­ecules form centrosymmetrical dimers via pairs of strong N—H⋯O hydrogen bonds and π–π stacking inter­actions between the two neighboring male­imide rings [centroid–centroid distance = 3.495 (2) Å]. The dimers are further linked by weak C—H⋯O and C—H⋯π hydrogen bonds into a three-dimensional framework. PMID:24764976

  9. A New Scrambling Evaluation Scheme Based on Spatial Distribution Entropy and Centroid Difference of Bit-Plane

    Science.gov (United States)

    Zhao, Liang; Adhikari, Avishek; Sakurai, Kouichi

    Watermarking is one of the most effective techniques for copyright protection and information hiding. It can be applied in many fields of our society. Nowadays, some image scrambling schemes are used as one part of the watermarking algorithm to enhance the security. Therefore, how to select an image scrambling scheme and what kind of the image scrambling scheme may be used for watermarking are the key problems. Evaluation method of the image scrambling schemes can be seen as a useful test tool for showing the property or flaw of the image scrambling method. In this paper, a new scrambling evaluation system based on spatial distribution entropy and centroid difference of bit-plane is presented to obtain the scrambling degree of image scrambling schemes. Our scheme is illustrated and justified through computer simulations. The experimental results show (in Figs. 6 and 7) that for the general gray-scale image, the evaluation degree of the corresponding cipher image for the first 4 significant bit-planes selection is nearly the same as that for the 8 bit-planes selection. That is why, instead of taking 8 bit-planes of a gray-scale image, it is sufficient to take only the first 4 significant bit-planes for the experiment to find the scrambling degree. This 50% reduction in the computational cost makes our scheme efficient.

  10. 3-Nitro-phenol-1,3,5-triazine-2,4,6-tri-amine (2/1).

    Science.gov (United States)

    Sangeetha, V; Kanagathara, N; Chakkaravarthi, G; Marchewka, M K; Anbalagan, G

    2013-06-01

    The asymmetric unit of the title compound, C3H6N6·2C6H5NO3, contains one melamine and two 3-nitro-phenol mol-ecules. The mean planes of the 3-nitro-phenol mol-ecules are almost orthogonal to the plane of melamine, making dihedral angles of 82.77 (4) and 88.36 (5)°. In the crystal, mol-ecules are linked via O-H⋯N, N-H⋯N and N-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal also features weak C-H⋯π and π-π inter-actions [centroid-centroid distance = 3.9823 (9) Å].

  11. Forecasting the Rupture Directivity of Large Earthquakes: Centroid Bias of the Conditional Hypocenter Distribution

    Science.gov (United States)

    Donovan, J.; Jordan, T. H.

    2012-12-01

    Forecasting the rupture directivity of large earthquakes is an important problem in probabilistic seismic hazard analysis (PSHA), because directivity is known to strongly influence ground motions. We describe how rupture directivity can be forecast in terms of the "conditional hypocenter distribution" or CHD, defined to be the probability distribution of a hypocenter given the spatial distribution of moment release (fault slip). The simplest CHD is a uniform distribution, in which the hypocenter probability density equals the moment-release probability density. For rupture models in which the rupture velocity and rise time depend only on the local slip, the CHD completely specifies the distribution of the directivity parameter D, defined in terms of the degree-two polynomial moments of the source space-time function. This parameter, which is zero for a bilateral rupture and unity for a unilateral rupture, can be estimated from finite-source models or by the direct inversion of seismograms (McGuire et al., 2002). We compile D-values from published studies of 65 large earthquakes and show that these data are statistically inconsistent with the uniform CHD advocated by McGuire et al. (2002). Instead, the data indicate a "centroid biased" CHD, in which the expected distance between the hypocenter and the hypocentroid is less than that of a uniform CHD. In other words, the observed directivities appear to be closer to bilateral than predicted by this simple model. We discuss the implications of these results for rupture dynamics and fault-zone heterogeneities. We also explore their PSHA implications by modifying the CyberShake simulation-based hazard model for the Los Angeles region, which assumed a uniform CHD (Graves et al., 2011).

  12. (E-3-[4-(Pentyloxyphenyl]-1-phenylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Asghar Abbas

    2009-06-01

    Full Text Available The title compound, C20H22O2, crystallizes with two independent molecules in the asymmetric unit. In each molecule, all the non-H atoms lie in a common plane (r.m.s. deviations of 0.098 and 0.079 Å. There is a π–π stacking interaction in the crystal structure. The central aromatic rings of the two molecules, which are stacked head-to-tail one above the other, are separated by centroid-to-centroid distances of 3.872 (13 and 3.999 (10 Å.

  13. Multiple anion...π interactions in tris(1,10-phenanthroline-κ(2)N,N')iron(II) bis[1,1,3,3-tetracyano-2-(2-hydroxyethyl)propenide] monohydrate.

    Science.gov (United States)

    Setifi, Zouaoui; Domasevitch, Konstantin V; Setifi, Fatima; Mach, Pavel; Ng, Seik Weng; Petříček, Vaclav; Dušek, Michal

    2013-11-01

    In the ionic structure of the title compound, [Fe(C12H8N2)3](C9H5N4O2)2·H2O, the octahedral tris-chelate [Fe(phen)3](2+) dications [Fe-N = 1.9647 (14)-1.9769 (14) Å; phen is 1,10-phenathroline] afford one-dimensional chains by a series of slipped π-π stacking interactions [centroid-to-centroid distances = 3.792 (3) and 3.939 (3) Å]. The 1,1,3,3-tetracyano-2-(2-hydroxyethyl)propenide anions, denoted tcnoetOH(-), reveal an appreciable delocalization of π-electron density, involving the central propenide [C-C = 1.383 (3)-1.401 (2) Å] fragment and four nitrile groups, and this is also supported by density functional theory (DFT) calculations at the B97D/6-311+G(2d,2p) level. Primary noncovalent inter-moiety interactions comprise conventional O-H...O(N) and weak C-H...O(N) hydrogen bonding [O...O(N) = 2.833 (2)-3.289 (5) Å and C...O(N) = 3.132 (2)-3.439 (2) Å]. The double anion...π interaction involving a nitrile group of tcnoetOH(-) and two cis-positioned pyridine rings (`π-pocket') of [Fe(phen)3](2+) [N...centroid = 3.212 (2) and 3.418 (2) Å] suggest the relevance of anion...π stackings for charge-diffuse polycyanoanions and common M-chelate species.

  14. Center for Research on Infrared Detectors (CENTROID)

    Science.gov (United States)

    2006-09-30

    of growth, x is also monitored in situ by SE, and Tis measured by a thermocouple, a pyrometer and indirectly by the heating power and is calibrated...Polar optical, acoustic , and inter-valley phonon scattering are included, as wells as scattering from the quantum dots. The simulation includes

  15. Crystal structure of 2-hy-droxy-imino-2-(pyridin-2-yl)-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.

    Science.gov (United States)

    Plutenko, Maxym O; Lampeka, Rostislav D; Haukka, Matti; Nordlander, Ebbe

    2014-12-01

    The mol-ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra-molecular N-H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of bifurcated O-H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π-π stacking inter-actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol-ecules, forming a three-dimensional structure.

  16. Crystal structure of 2-hy­droxy­imino-2-(pyridin-2-yl)-N′-[1-(pyridin-2-yl)ethyl­idene]acetohydrazide

    Science.gov (United States)

    Plutenko, Maxym O.; Lampeka, Rostislav D.; Haukka, Matti; Nordlander, Ebbe

    2014-01-01

    The mol­ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra­molecular N—H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol­ecules are linked by pairs of bifurcated O—H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C—H⋯O and C—H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π–π stacking inter­actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol­ecules, forming a three-dimensional structure. PMID:25552998

  17. Crystal structure of bis-(3-bromo-pyridine-κN)bis-(O-ethyl di-thio-carbonato-κ(2) S,S')nickel(II).

    Science.gov (United States)

    Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

    2015-01-01

    In the title mol-ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni(2+) cation is located on a centre of inversion and has a distorted octa-hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C-S bond lengths of the thio-carboxyl-ate group are indicative of a delocalized bond and the O-Csp (2) bond is considerably shorter than the O-Csp (3) bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol-ecules is stabilized by C-H⋯S and C-H⋯π inter-actions. In addition, π-π inter-actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol-ecules are arranged in rows along [100], forming layers parallel to (010) and (001).

  18. Component optimization of dairy manure vermicompost, straw, and peat in seedling compressed substrates using simplex-centroid design.

    Science.gov (United States)

    Yang, Longyuan; Cao, Hongliang; Yuan, Qiaoxia; Luoa, Shuai; Liu, Zhigang

    2018-03-01

    Vermicomposting is a promising method to disposal dairy manures, and the dairy manure vermicompost (DMV) to replace expensive peat is of high value in the application of seedling compressed substrates. In this research, three main components: DMV, straw, and peat, are conducted in the compressed substrates, and the effect of individual components and the corresponding optimal ratio for the seedling production are significant. To address these issues, the simplex-centroid experimental mixture design is employed, and the cucumber seedling experiment is conducted to evaluate the compressed substrates. Results demonstrated that the mechanical strength and physicochemical properties of compressed substrates for cucumber seedling can be well satisfied with suitable mixture ratio of the components. Moreover, DMV, straw, and peat) could be determined at 0.5917:0.1608:0.2475 when the weight coefficients of the three parameters (shoot length, root dry weight, and aboveground dry weight) were 1:1:1. For different purpose, the optimum ratio can be little changed on the basis of different weight coefficients. Compressed substrate is lump and has certain mechanical strength, produced by application of mechanical pressure to the seedling substrates. It will not harm seedlings when bedding out the seedlings, since the compressed substrate and seedling are bedded out together. However, there is no one using the vermicompost and agricultural waste components of compressed substrate for vegetable seedling production before. Thus, it is important to understand the effect of individual components to seedling production, and to determine the optimal ratio of components.

  19. Minimization of the transformer inter-winding parasitic capacitance for modular stacking power supply applications

    DEFF Research Database (Denmark)

    Nguyen-Duy, Khiem; Ouyang, Ziwei; Knott, Arnold

    2014-01-01

    In an isolated power supply, the inter-winding parasitic capacitance plays a vital role in the mitigation of common mode noise currents created by fast voltage transient responses. The lower the transformer inter-winding capacitance, the more immune the power supply is to fast voltage transient...... responses. This requirement is even more critical for modular stacking applications in which multiple power supplies are stacked. This paper addresses the issue by presenting a detailed analysis and design of an unconventional isolated power supply that uses a ring core transformer with a very low inter......-winding parasitic capacitance of 10 pF. Considering its output power of 300 W, this approach yields about 0.033 pF/W inter-winding capacitance over output power, approximately thirty times lower than existing approaches in the literature. This makes the converter a suitable solution for modular stacking of fast...

  20. Influence factors of the inter-nanowire thermal contact resistance in the stacked nanowires

    Science.gov (United States)

    Wu, Dongxu; Huang, Congliang; Zhong, Jinxin; Lin, Zizhen

    2018-05-01

    The inter-nanowire thermal contact resistance is important for tuning the thermal conductivity of a nanocomposite for thermoelectric applications. In this paper, the stacked copper nanowires are applied for studying the thermal contact resistance. The stacked copper nanowires are firstly made by the cold-pressing method, and then the nanowire stacks are treated by sintering treatment. With the effect of the volumetric fraction of nanowires in the stack and the influence of the sintering-temperature on the thermal contact resistance discussed, results show that: The thermal conductivity of the 150-nm copper nanowires can be enlarged almost 2 times with the volumetric fraction increased from 32 to 56% because of the enlarged contact-area and contact number of a copper nanowire. When the sintering temperature increases from 293 to 673 K, the thermal conductivity of the stacked 300-nm nanowires could be enlarged almost 2.5 times by the sintering treatment, because of the improved lattice property of the contact zone. In conclusion, application of a high volumetric fraction or/and a sintering-treatment are effectivity to tune the inter-nanowire thermal contact resistance, and thus to tailor the thermal conductivity of a nanowire network or stack.

  1. Quinolinium 8-hy-droxy-7-iodo-quinoline-5-sulfonate 0.8-hydrate.

    Science.gov (United States)

    Smith, Graham

    2012-12-01

    In the crystal structure of the title hydrated quinolinium salt of ferron (8-hy-droxy-7-iodo-quinoline-5-sulfonic acid), C9H7N(+)·C9H5INO4S(-)·0.8H2O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37) lying essentially within a common plane and with the ferron anions forming π-π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6) Å]. The cations and anions are linked into chains extending along c through hy-droxy O-H⋯O and quinolinium N-H⋯O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O-H⋯O hydrogen-bonding inter-actions along b, giving a two-dimensional network.

  2. 5,7-Dibromo-8-methoxyquinoline

    Directory of Open Access Journals (Sweden)

    Ísmail Çelik

    2017-05-01

    Full Text Available In the title compound, C10H7Br2NO, the methoxy C atom deviates from the quinoline ring system (r.m.s deviation = 0.003 Å by 1.204 (4 Å. In the crystal, C—H...O hydrogen bonds link the molecules into infinite chains along the b-axis direction. Aromatic π–π stacking interactions [centroid-to-centroid distance = 3.7659 (19 Å] are also observed.

  3. (Pyridin-2-ylmethyl 6-bromo-2-oxo-1-[(pyridin-2-ylmethyl]-1,2-dihydroquinoline-4-carboxylate

    Directory of Open Access Journals (Sweden)

    Yassir Filali Baba

    2018-02-01

    Full Text Available In the central dihydroquinoline unit of the title compound, C22H16BrN3O3, the dihydropyridinone and benzene rings are inclined to one another by 2.0 (1°, while the outer pyridine rings are almost perpendicular to the plane of the dihydroquinoline ring system. The conformation of the molecule is partially determined by an intramolecular C—H...O hydrogen bond. In the crystal, molecules stack along the b-axis direction through a combination of C—H...N and C—H...O hydrogen bonds and π–π stacking interactions involving the dihydroquinoline units, with a centroid-to-centroid distance of 3.7648 (15 Å.

  4. Crystal structure of bis­(3-bromo­pyridine-κN)bis­(O-ethyl di­thio­carbonato-κ2 S,S′)nickel(II)

    Science.gov (United States)

    Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

    2015-01-01

    In the title mol­ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni2+ cation is located on a centre of inversion and has a distorted octa­hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C—S bond lengths of the thio­carboxyl­ate group are indicative of a delocalized bond and the O—Csp 2 bond is considerably shorter than the O—Csp 3 bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol­ecules is stabilized by C—H⋯S and C—H⋯π inter­actions. In addition, π–π inter­actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol­ecules are arranged in rows along [100], forming layers parallel to (010) and (001). PMID:25705471

  5. Combined effect of carnosol, rosmarinic acid and thymol on the oxidative stability of soybean oil using a simplex centroid mixture design.

    Science.gov (United States)

    Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Jiménez, Ignacio A; Lorenzo-Morales, Jacob; Piñero, José E; Bouassida-Beji, Maha; Hamdi, Moktar; L Bazzocchi, Isabel

    2017-08-01

    Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. Results showed that bioactive compounds are effective in maintaining oxidative stability of soybean oil. However, the binary interaction of rosmarinic acid and thymol caused a reduction in antioxidant activity and oxidative stability of soybean oil. Optimum conditions for maximum antioxidant activity and oxidative stability were found to be an equal ternary mixture of carnosol, rosmarinic acid and thymol. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Kinetic equilibrium of space charge dominated beams in a misaligned quadrupole focusing channel

    International Nuclear Information System (INIS)

    Goswami, A.; Sing Babu, P.; Pandit, V. S.

    2013-01-01

    The dynamics of intense beam propagation through the misaligned quadrupole focusing channel has been studied in a self-consistent manner using nonlinear Vlasov-Maxwell equations. The equations of motion of the beam centroid have been developed and found to be independent of any specific beam distribution. A Vlasov equilibrium distribution and beam envelope equations have been obtained, which provide us a theoretical tool to investigate the dynamics of intense beam propagating in a misaligned quadrupole focusing channel. It is shown that the displaced quadrupoles only cause the centroid of the beam to wander off axis. The beam envelope around the centroid obeys the familiar Kapchinskij-Vladimirskij envelope equation that is independent of the centroid motion. However, the rotation of the quadrupole about its optical axis affects the beam envelope and causes an increase in the projected emittances in the two transverse planes due to the inter-plane coupling

  7. Pyridinium bis­(pyridine-κN)tetra­kis­(thio­cyanato-κN)ferrate(III)–pyrazine-2-carbo­nitrile–pyridine (1/4/1)

    Science.gov (United States)

    Shylin, Sergii I.; Gural’skiy, Il’ya A.; Haukka, Matti; Golenya, Irina A.

    2013-01-01

    In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2]·4C5H3N3·C5H5N, the FeIII ion is located on an inversion centre and is six-coordinated by four N atoms of the thio­cyanate ligands and two pyridine N atoms in a trans arrangement, forming a slightly distorted octa­hedral geometry. A half-occupied H atom attached to a pyridinium cation forms an N—H⋯N hydrogen bond with a centrosymmetrically-related pyridine unit. Four pyrazine-2-carbo­nitrile mol­ecules crystallize per complex anion. In the crystal, π–π stacking inter­actions are present [centroid–centroid distances = 3.6220 (9), 3.6930 (9), 3.5532 (9), 3.5803 (9) and 3.5458 (8) Å]. PMID:23723782

  8. 5-Chloro-2-methyl-3-phenylsulfonyl-1-benzofuran

    Directory of Open Access Journals (Sweden)

    Hong Dae Choi

    2008-07-01

    Full Text Available The title compound, C15H11ClO3S, was prepared by the oxidation of 5-chloro-2-methyl-3-phenylsulfanyl-1-benzofuran with 3-chloroperoxybenzoic acid. There are two symmetry-independent molecules in the asymmetric unit. The dihedral angles formed by the phenyl ring and the plane of the benzofuran system are 77.80 (8 and 78.34 (8°. The crystal structure is stabilized by aromatic π–π stacking interactions between the furan ring and the benzene rings of neighbouring benzofuran fragments from two symmetry-independent molecules; the centroid–centroid distances within the stacks are 3.689 (4, 3.702 (4, 3.825 (4 and 3.826 (4 Å. Additionally, the stacked molecules exhibit inter- and intramolecular C—H...O interactions.

  9. Multiresponse optimisation on biodiesel obtained through a ternary mixture of vegetable oil and animal fat: Simplex-centroid mixture design application

    International Nuclear Information System (INIS)

    Orives, Juliane Resges; Galvan, Diego; Coppo, Rodolfo Lopes; Rodrigues, Cezar Henrique Furtoso; Angilelli, Karina Gomes; Borsato, Dionísio

    2014-01-01

    Highlights: • Mixture experimental design was used which allowed evaluating various responses. • Predictive equation was presented that allows verifying the behavior of the mixtures. • The results depicted that the obtained biodiesel dispensed the use of any additives. - Abstract: The quality of biodiesel is a determining factor in its commercialisation, and parameters such as the Cold Filter Plugging Point (CFPP) and Induction Period (IP) determine its operability in engines on cold days and storage time, respectively. These factors are important in characterisation of the final product. A B100 biodiesel formulation was developed using a multiresponse optimisation, for which the CFPP and cost were minimised, and the IP and yield were maximised. The experiments were carried out according to a simplex-centroid mixture design using soybean oil, beef tallow, and poultry fat. The optimum formulation consisted of 50% soybean oil, 20% beef tallow, and 30% poultry fat and had CFPP values of 1.92 °C, raw material costs of US$ 903.87 ton −1 , an IP of 8.28 h, and a yield of 95.68%. Validation was performed in triplicate and the t-test indicated that there were no difference between the estimated and experimental values for none of the dependent variables, thus indicating efficiency of the joint optimisation in the biodiesel production process that met the criteria for CFPP and IP, as well as high yield and low cost

  10. (Carbonato-κ2 O,O′)bis­(5,5′-dimethyl-2,2′-bipyridyl-κ2 N,N′)cobalt(III) bromide trihydrate

    Science.gov (United States)

    Arun Kumar, Kannan; Meera, Parthsarathi; Amutha Selvi, Madhavan; Dayalan, Arunachalam

    2012-01-01

    In the title complex, [Co(CO3)(C12H12N2)2]Br·3H2O, the CoIII cation has a distorted octa­hedral coordination environment. It is chelated by four N atoms of two different 5,5′-dimethyl-2,2′-bipyridyl (dmbpy) ligands in axial and equatorial positions, and by two O atoms of a carbonate anion completing the equatorial positions. Although the water mol­ecules are disordered and their H atoms were not located, there are typical O⋯O distances between 2.8 and 3.0 Å, indicating O—H⋯O hydrogen bonding. The crystal packing is consolidated by C—H⋯O and C—H⋯Br hydrogen bonds, as well as π–π stacking inter­actions between adjacent pyridine rings of the dmbpy ligands, with centroid–centroid distances of 3.694 (3) and 3.7053 (3) Å. PMID:22589773

  11. 2,2′-Dimethyl-1,1′-[2,2-bis(bromomethylpropane-1,3-diyl]dibenzimidazole hemihydrate

    Directory of Open Access Journals (Sweden)

    Yong-Sheng Yan

    2012-03-01

    Full Text Available The title compound, C21H22Br2N4·0.5H2O, contains two benzimidazole groups which may provide two potential coordination nodes for the construction of metal–organic frameworks. The mean planes of the two imidazole groups are almost perpendicular, with a dihedral angle of 83.05 (2°, and adjacent molecules are linked into a one-dimensional chain by π–π stacking interactions between imidazole groups of different molecules [centroid-to-centroid distances of 3.834 (2 and 3.522 (2 Å].

  12. 4-Chloro­selanyl-3,5-diethyl-1H-pyrazol-2-ium chloride

    Science.gov (United States)

    Seredyuk, Maksym; Znovjyak, Kateryna O.; Sliva, Tetyana Yu.; Haukka, Matti; Fritsky, Igor O.

    2011-01-01

    In the cation of the title compound, C7H12ClN2Se+·Cl−, the ethyl­ene groups and the Se–Cl fragment adopt a cis configuration with a C—Se—Cl angle of 96.09 (6)°. In the crystal, inter­molecular N—H⋯Cl hydrogen bonds link two cations and two chlorine anions into centrosymmetric clusters. π–π inter­actions between the pyrazole rings [centroid–centroid distance of 3.530 (2) Å] link these clusters into columns along [001] with short inter­molecular Se⋯Cl− contacts of 2.995 (1) Å. PMID:22220089

  13. A protein relational database and protein family knowledge bases to facilitate structure-based design analyses.

    Science.gov (United States)

    Mobilio, Dominick; Walker, Gary; Brooijmans, Natasja; Nilakantan, Ramaswamy; Denny, R Aldrin; Dejoannis, Jason; Feyfant, Eric; Kowticwar, Rupesh K; Mankala, Jyoti; Palli, Satish; Punyamantula, Sairam; Tatipally, Maneesh; John, Reji K; Humblet, Christine

    2010-08-01

    The Protein Data Bank is the most comprehensive source of experimental macromolecular structures. It can, however, be difficult at times to locate relevant structures with the Protein Data Bank search interface. This is particularly true when searching for complexes containing specific interactions between protein and ligand atoms. Moreover, searching within a family of proteins can be tedious. For example, one cannot search for some conserved residue as residue numbers vary across structures. We describe herein three databases, Protein Relational Database, Kinase Knowledge Base, and Matrix Metalloproteinase Knowledge Base, containing protein structures from the Protein Data Bank. In Protein Relational Database, atom-atom distances between protein and ligand have been precalculated allowing for millisecond retrieval based on atom identity and distance constraints. Ring centroids, centroid-centroid and centroid-atom distances and angles have also been included permitting queries for pi-stacking interactions and other structural motifs involving rings. Other geometric features can be searched through the inclusion of residue pair and triplet distances. In Kinase Knowledge Base and Matrix Metalloproteinase Knowledge Base, the catalytic domains have been aligned into common residue numbering schemes. Thus, by searching across Protein Relational Database and Kinase Knowledge Base, one can easily retrieve structures wherein, for example, a ligand of interest is making contact with the gatekeeper residue.

  14. Development and optimization of a mixed beverage made of whey and water-soluble soybean extract flavored with chocolate using a simplex-centroid design

    Directory of Open Access Journals (Sweden)

    Dóris Faria de OLIVEIRA

    2017-10-01

    Full Text Available Abstract This study aimed to combine the nutritional advantages of whey and soybean by developing a type of chocolate beverage with water-soluble soybean extract dissolved in whey. Different concentrations of thickeners (carrageenan, pectin and starch – maximum level of 500 mg.100 mL-1 were tested by a simplex-centroid design. Several physicochemical, rheological, and sensory properties of the beverages were measured and a multi-response optimization was conducted aiming to obtain a whey and soybean beverage with increased overall sensory impression and maximum purchase intention. Beverages presented mean protein levels higher than 3.1 g.100 mL-1, a low content of lipids (< 2 g.100 mL-1 and total soluble solids ≥20 g.100 mL-1. Response surface methodology was applied and the proposed for overall impression and purchase intention presented R2=0.891 and R2=0.966, respectively. The desirability index (d-value=0.92 showed that the best formulation should contain 46% carrageenan and 54% pectin in the formulation. The formulation manufactured with this combination of thickeners was tested and the overall impression was 7.11±1.09 (over a 9-point hedonic scale and the purchase intention was 4.0±1.3 (over a 5-point hedonic scale, thus showing that the proposed models were predictive.

  15. Bis(8-hydroxy-1-methylquinolin-1-ium bis(1,2-dicyanoethene-1,2-dithiolatonickelate(II dihydrate

    Directory of Open Access Journals (Sweden)

    Zhi-Heng Guan

    2011-12-01

    Full Text Available In the title ion-pair complex, (C10H10NO2[Ni(C4N2S22]·2H2O, the anion has crystallographically imposed centre of symmetry. The NiII atom exhibits a slightly distorted square-planar coordination geometry. In the crystal, the water molecule links anions and cations into a three-dimensional network via O—H...N, O—H...S and O—H...O hydrogen bonds. The structure is further stabilized by weak S...π contacts [S...centroid = 3.8047 (9 Å] and π–π stacking interactions [centriod–centroid distance = 3.8653 (7 Å].

  16. InterAction Database (IADB)

    Science.gov (United States)

    The InterAction Database includes demographic and prescription information for more than 500,000 patients in the northern and middle Netherlands and has been integrated with other systems to enhance data collection and analysis.

  17. Action research in inter-organisational networks

    DEFF Research Database (Denmark)

    Goduscheit, René Chester; Rasmussen, Erik Stavnsager; Jørgensen, Jacob Høj

    2007-01-01

    Traditionally, the literature on action research has been aimed at intra-organisational issues. These studies have distinguished between two researcher roles: The problem-solver and the observer. This article addresses the distinct challenges of action research in inter-organisational projects....... In addition to the problem-solver and observer roles, the researcher in an inter-organisational setting can serve as a legitimiser of the project and manage to involve partners that in an ordinary business-to-business setting would not have participated. Based on an action research project in a Danish inter......-organisational network, this article discusses potential pitfalls in the legitimiser role. Lack of clarity in defining the researcher role and project ownership in relation to the funding organisation and the rest of the network can jeopardise the project and potentially the credibility of the researchers. The article...

  18. 2-{(E-[(2Z-2-(1,2-Dihydrophthalazin-1-ylidenehydrazinylidene]methyl}phenol

    Directory of Open Access Journals (Sweden)

    M. K. Prasanna

    2013-10-01

    Full Text Available The title compound, C15H12N4O, adopts an E conformation with respect to the azomethine bond and crystallizes in its hydrazinylidene tautomeric form. The dihedral angle between the ring systems is 15.98 (7°. The phenol O—H group forms an intramolecular O—H...N hydrogen bond. In the crystal, pairs of N—H...N and C—H...O hydrogen bonds link neighbouring molecules into centrosymmetric dimers. These dimers are interconnected by means of three types of π–π stacking interactions. One, with a centroid–centroid distance of 3.577 (1 Å [interplanar separation = 3.4673 (6 Å], connects adjacent molecules into centrosymmetric dimers. The other two interactions, on the outward facing sides of the dimers, are between phenol rings of neighboring molecules [centroid–centroid separation = 3.7907 (13 Å and interplanar separation = 3.5071 (8 Å], and between phthalazin units [centroid–centroid separation = 3.6001 (12 Å and interplanar separation = 3.4891 (7 Å]. In combination, the π–π interactions lead to the formation of infinite layers with molecules stacked along [0-11]. These layers are, in turn, connected with neighbouring layers through the N—H...N and C—H...O hydrogen bonds, yielding a three-dimensional supramolecular architecture.

  19. 2-(4-Methylphenyl-7-(2-methylpropoxy-4H-chromen-4-one–6-chloro-2-(4-methylphenyl-7-(2-methylpropoxy-4H-chromen-4-one (19/1

    Directory of Open Access Journals (Sweden)

    Vijay M. Barot

    2012-08-01

    Full Text Available The title co-crystal, 0.95C20H20O3·0.05C20H19ClO3, arises as the chloride carried over during the synthesis shares a position with an aromatic H atom; the partial occupancies are 0.947 (2 and 0.053 (2 for H and Cl, respectively. The molecular structure is stabilized by intramolecular C—H...O contacts, forming pseudo five- and six-membered rings with S(5 and S(6 graph-set motifs, respectively. The crystal structure features π–π stacking interactions between the centroids of the central fused ring systems [centroid–centroid distance = 3.501 (2 Å].

  20. Crystal structure of 4-meth-oxy-N-(piperidine-1-carbono-thio-yl)benzamide.

    Science.gov (United States)

    Suhud, Khairi; Hasbullah, Siti Aishah; Ahmad, Musa; Heng, Lee Yook; Kassim, Mohammad B

    2017-10-01

    In the title compound, C 14 H 18 N 2 O 2 S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-meth-oxy-benzoyl ring, with a dihedral angle of 63.0 (3)°. The central N-C(=S)-N(H)-C(=O) bridge is twisted with an N-C-N-C torsion angle of 74.8 (6)°. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains along the c -axis direction. Adjacent chains are linked by C-H⋯π inter-actions, forming layers parallel to the ac plane. The layers are linked by offset π-π inter-actions [inter-centroid distance = 3.927 (3) Å], forming a supra-molecular three-dimensional structure.

  1. (E)-6-Amino-1,3-dimethyl-5-[(pyridin-2-yl-methyl-idene)amino]-pyrimidine-2,4(1H,3H)-dione.

    Science.gov (United States)

    Booysen, Irvin; Hlela, Thulani; Ismail, Muhammed; Gerber, Thomas; Hosten, Eric; Betz, Richard

    2011-09-01

    In the title compound, C(12)H(13)N(5)O(2), a Schiff-base-derived chelate ligand, the non-aromatic heterocycle and its substituents essentially occupy one common plane (r.m.s. of fitted non-H atoms = 0.0503 Å). The N=C bond is E-configured. Intra-cyclic angles in the pyridine moiety cover the range 117.6 (2)-124.1 (2)°. Intra- and inter-molecular N-H⋯N and N-H⋯O hydrogen bonds are observed in the crystal structure, as are intra- and inter-molecular C-H⋯O contacts which, in total, connect the mol-ecules into a three-dimensional network. The shortest ring-centroid-to-ring-centroid distance of 3.5831 (14) Å is between the two different types of six-membered rings.

  2. Ethyl 3-[7-eth­oxy-6-(4-meth­oxy­benzene­sulfonamido)-2H-indazol-2-yl]propano­ate

    Science.gov (United States)

    Abbassi, Najat; Oulemda, Bassou; Rakib, El Mostapha; Geffken, Detlef; Zouihri, Hafid

    2012-01-01

    In the title compound, C21H25N3O6S, the dihedral angle between the meth­oxy­benzene and indazole rings is 74.96 (5)°. The crystal packing is stabilized by an N—H⋯O hydrogen bond into a two-dimensional network. In addition, C—H⋯π inter­actions and a π–π contact, with a centroid–centroid distance of 3.5333 (6) Å, are observed. The crystal packing is stabilized by N—H⋯O and C—H⋯O hydrogen bonds. PMID:22589994

  3. 2,2′-Dihydroxybiphenyl-3,3′-dicarbaldehyde dioxime

    Directory of Open Access Journals (Sweden)

    Ekaterina Golovnia

    2009-08-01

    Full Text Available The molecule of the title compound, C14H12N2O4, lies across a crystallographic inversion centre situated at the mid-point of the C—C intra-annular bond. The molecule is not planar, the dihedral angle between the aromatic rings being 50.1 (1°. The oxime group is in an E position with respect to the –OH group and forms an intramolecular O—H...N hydrogen bond. In the crystal structure, intermolecular O—H...O hydrogen bonds link molecules into chains propagating along [001]. The crystal structure is further stabilized by intermolecular stacking interactions between the rings [centroid-to-centroid distance = 3.93 (1 Å], resulting in layers parallel to the bc plane.

  4. Crystal structure of the bora-benzene-2,6-lutidine adduct.

    Science.gov (United States)

    Kivijärvi, Lauri; Haukka, Matti

    2015-12-01

    In the title compound, C12H14BN, the complete mol-ecule is generated by a crystallographic twofold axis, with two C atoms, the B atom and the N atom lying on the rotation axis. The dihedral angle between the bora-benzene and pyridine rings is 81.20 (6)°. As well as dative electron donation from the N atom to the B atom [B-N = 1.5659 (18) Å], the methyl substituents on the lutidine ring shield the B atom, which further stabilizes the mol-ecule. In the crystal, weak aromatic π-π stacking between the pyridine rings [centroid-centroid separation = 3.6268 (9) Å] is observed, which generates [001] columns of mol-ecules.

  5. Crystal structure of 4-meth­oxy-N-(piperidine-1-carbono­thio­yl)benzamide

    Science.gov (United States)

    Suhud, Khairi; Hasbullah, Siti Aishah; Ahmad, Musa; Heng, Lee Yook

    2017-01-01

    In the title compound, C14H18N2O2S, the piperidine ring has a chair conformation. Its mean plane is twisted with respect to the 4-meth­oxy­benzoyl ring, with a dihedral angle of 63.0 (3)°. The central N—C(=S)—N(H)—C(=O) bridge is twisted with an N—C—N—C torsion angle of 74.8 (6)°. In the crystal, mol­ecules are linked by N—H⋯O and C—H⋯O hydrogen bonds, forming chains along the c-axis direction. Adjacent chains are linked by C—H⋯π inter­actions, forming layers parallel to the ac plane. The layers are linked by offset π–π inter­actions [inter­centroid distance = 3.927 (3) Å], forming a supra­molecular three-dimensional structure. PMID:29250374

  6. Variability of inter-team distances associated with match events in elite-standard soccer

    NARCIS (Netherlands)

    Frencken, Wouter; De Poel, Harjo; Visscher, Chris; Lemmink, Koen

    2012-01-01

    In soccer, critical match events like goal attempts can be preceded by periods of instability in the balance between the two teams' behaviours. Therefore, we determined periods of high variability in the distance between the teams' centroid positions longitudinally and laterally in an

  7. Crystal structure of 4,4′,4′′-(1,3,5-triazine-2,4,6-triyltripyridinium trichloride 2.5-hydrate

    Directory of Open Access Journals (Sweden)

    Bo-Kai Ling

    2015-11-01

    Full Text Available The asymmetric unit of the title compound, C18H15N63+·3Cl−·2.5H2O, contains two independent (1,3,5-triazine-2,4,6-triyltripyridinium cations. Both cations are approximately planar, the r.m.s. deviations of fitted non-H atoms being 0.045 and 0.051 Å. In the crystal, extensive O—H...Cl, O—H...O, N—H...Cl and N—H...O hydrogen bonds and weak C—H...Cl and C—H...O interactions link the organic cations, Cl− anions and water molecules into a three-dimensional supramolecular architecture. π–π stacking between the pyridine rings of adjacent cations is also observed, the centroid-to-centroid distance being 3.7578 (8 Å.

  8. Crystal structure of dichloridobis(dimethyl N-cyanodithioiminocarbonatecobalt(II

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2016-01-01

    Full Text Available The structure of the mononuclear title complex, [{(H3CS2C=NC[triple-bond] N}2CoCl2], consists of a CoII atom coordinated in a distorted tetrahedral manner by two Cl− ligands and the terminal N atoms of two dimethyl N-cyanodithioiminocarbonate ligands. The two organic ligands are almost coplanar, with a dihedral angle of 5.99 (6° between their least-squares planes. The crystal packing features pairs of inversion-related complexes that are held together through C—H...Cl and C—H...S interactions and π–π stacking [centroid-to-centroid distance = 3.515 (su? Å]. Additional C—H...Cl and C—H...S interactions, as well as Cl...S contacts < 3.6 Å, consolidate the crystal packing.

  9. Crystal structure of 4-methylsulfanyl-2-phenylquinazoline

    Directory of Open Access Journals (Sweden)

    Mohammed B. Alshammari

    2014-08-01

    Full Text Available In the title compound, C15H12N2S, the methylthioquinazoline group is planar with the methyl C displaced by only 0.116 (3 Å from the plane of the quinazoline moiety. The dihedral angle between the phenyl ring and the quinazoline ring system is 13.95 (5°. In the crystal, each molecule is linked by π–π stacking between to two adjacent inversion-related molecules. On one side, the inverted quinazoline groups interact with a centroid–centroid distance of 3.7105 (9 Å. On the other side, the quinazoline group interacts with the pyrimidine and phenyl rings of the second neighbour with centroid–centroid distances of 3.5287 (8 and 3.8601 (9 Å, respectively.

  10. Crystal structure of hexaaquanickel(II bis{2-[(5,6-dihydroxy-3-sulfonatoquinolin-1-ium-7-yloxy]acetate} dihydrate

    Directory of Open Access Journals (Sweden)

    Hai Le Thi Hong

    2015-09-01

    Full Text Available The asymmetric unit of the title compound, [Ni(H2O6](C11H8NO8S2·2H2O, features a half-hexaaquanickel(II complex cation with the NiII ion on an inversion center, one deprotonated 5,6-dihydroxy-3-sulfoquinolin-7-yloxyacetic acid (QOH molecule appearing in its zwitterionic form and one lattice water molecule. The sulfonate group is disordered over two positions with occupancy factors of 0.655 (5 and 0.345 (5. The hexaaquanickel(II cation interacts through hydrogen bonding with eight QOH molecules and two water molecules. The six-membered rings of quinoline show π–π stacking [centroid-to-centroid distances of 3.679 (2 Å and 3.714 (2 Å].

  11. Crystal structure of 2,5-dimethylanilinium salicylate

    Directory of Open Access Journals (Sweden)

    A. Mani

    2015-09-01

    Full Text Available The title molecular salt, C8H12N+·C7H5O3− arose from the proton-transfer reaction between 2,5-xylidine and salicylic acid. In the anion, the dihedral angle between the planes of the aromatic ring and the –CO2− group is 11.08 (8°; this near planarity is consolidated by an intramolecular O—H...O hydrogen bond. In the crystal, the components are connected by N—H...O hydrogen bonds, with all three O atoms in the anion acting as acceptors; the result is a [100] chain. The structure also features weak C—H...O bonds and aromatic π–π stacking [centroid-to-centroid distance = 3.7416 (10 Å] interactions, which lead to a three-dimensional network.

  12. Aeroelastically coupled blades for vertical axis wind turbines

    Science.gov (United States)

    Paquette, Joshua; Barone, Matthew F.

    2016-02-23

    Various technologies described herein pertain to a vertical axis wind turbine blade configured to rotate about a rotation axis. The vertical axis wind turbine blade includes at least an attachment segment, a rear swept segment, and optionally, a forward swept segment. The attachment segment is contiguous with the forward swept segment, and the forward swept segment is contiguous with the rear swept segment. The attachment segment includes a first portion of a centroid axis, the forward swept segment includes a second portion of the centroid axis, and the rear swept segment includes a third portion of the centroid axis. The second portion of the centroid axis is angularly displaced ahead of the first portion of the centroid axis and the third portion of the centroid axis is angularly displaced behind the first portion of the centroid axis in the direction of rotation about the rotation axis.

  13. Analysis of k-means clustering approach on the breast cancer Wisconsin dataset.

    Science.gov (United States)

    Dubey, Ashutosh Kumar; Gupta, Umesh; Jain, Sonal

    2016-11-01

    Breast cancer is one of the most common cancers found worldwide and most frequently found in women. An early detection of breast cancer provides the possibility of its cure; therefore, a large number of studies are currently going on to identify methods that can detect breast cancer in its early stages. This study was aimed to find the effects of k-means clustering algorithm with different computation measures like centroid, distance, split method, epoch, attribute, and iteration and to carefully consider and identify the combination of measures that has potential of highly accurate clustering accuracy. K-means algorithm was used to evaluate the impact of clustering using centroid initialization, distance measures, and split methods. The experiments were performed using breast cancer Wisconsin (BCW) diagnostic dataset. Foggy and random centroids were used for the centroid initialization. In foggy centroid, based on random values, the first centroid was calculated. For random centroid, the initial centroid was considered as (0, 0). The results were obtained by employing k-means algorithm and are discussed with different cases considering variable parameters. The calculations were based on the centroid (foggy/random), distance (Euclidean/Manhattan/Pearson), split (simple/variance), threshold (constant epoch/same centroid), attribute (2-9), and iteration (4-10). Approximately, 92 % average positive prediction accuracy was obtained with this approach. Better results were found for the same centroid and the highest variance. The results achieved using Euclidean and Manhattan were better than the Pearson correlation. The findings of this work provided extensive understanding of the computational parameters that can be used with k-means. The results indicated that k-means has a potential to classify BCW dataset.

  14. N-Cyclohexyl-2-(5-fluoro-1H-indol-3-yl-2-oxoacetamide

    Directory of Open Access Journals (Sweden)

    Dan-Li Tian

    2011-07-01

    Full Text Available In title compound, C16H17FN2O2, the cyclohexane ring adopts a chair conformation.. The crystal packing is stabilized by weak π–π stacking interactions [centroid–centroid distance = 3.503 (5 Å] and intermolecular C—H...O, N—H...O and N—H...F hydrogen-bond interactions.

  15. 1,3-Dimethyl-1H-indole-2-carbonitrile

    Directory of Open Access Journals (Sweden)

    Jiang-Sheng Li

    2009-08-01

    Full Text Available The title compound, C11H10N2, crystallizes with two molecules in the asymmetric unit, both of which are essentially planar (r.m.s. deviations = 0.014 and 0.016 Å. In the crystal, aromatic π–π stacking interactions occur [shortest centroid–centroid separation = 3.5569 (11 Å].

  16. 2,3-Diamino-pyridinium 6-carb-oxy-pyridine-2-carboxyl-ate.

    Science.gov (United States)

    Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

    2011-12-01

    The asymmetric unit of the title proton-transfer compound, C(5)H(8)N(3) (+)·C(7)H(4)NO(4) (-), consists of one mono-deprotonated pyridine-2,6-dicarb-oxy-lic acid as anion and one protonated 2,3-diamino-pyridine as cation. The crystal packing shows extensive O-H⋯O, N-H⋯O and N-H⋯N hydrogen bonds. Thre are also several π-π inter-actions between the anions and also between the cations [centriod-centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å].

  17. A monoclinic polymorph of (1E,5E)-1,5-bis-(2-hy-droxy-benzyl-idene)thio-carbono-hydrazide.

    Science.gov (United States)

    Schmitt, Bonell; Gerber, Thomas; Hosten, Eric; Betz, Richard

    2011-08-01

    The title compound, C(15)H(14)N(4)O(2)S, is a derivative of thio-ureadihydrazide. In contrast to the previously reported polymorph (ortho-rhom-bic, space group Pbca, Z = 8), the current study revealed monoclinic symmetry (space group P2(1)/n, Z = 4). The mol-ecule shows non-crystallographic C(2) as well as approximate C(s) symmetry. Intra-molecular bifurcated O-H⋯(N,S) hydrogen bonds, are present. In the crystal, inter-molecular N-H⋯S hydrogen bonds and C-H⋯π contacts connect the mol-ecules into undulating chains along the b axis. The shortest centroid-centroid distance between two aromatic systems is 4.5285 (12) Å.

  18. 3-Benzyl-4-ethyl-1H-1,2,4-triazole-5(4H)-thione.

    Science.gov (United States)

    Karczmarzyk, Zbigniew; Pitucha, Monika; Wysocki, Waldemar; Pachuta-Stec, Anna; Stańczuk, Andrzej

    2013-02-01

    The title compound, C(11)H(13)N(3)S, exists in the 5-thioxo tautomeric form. The benzene ring exhibits disorder with a refined ratio of 0.77 (2):0.23 (2) for components A and B with a common bridgehead C atom. The 1,2,4-triazole ring is essentially planar, with a maximum deviation of 0.002 (3) Å for the benzyl-substituted C atom, and forms dihedral angles of 88.94 (18) and 86.56 (49)° with the benzene rings of components A and B, respectively. The angle between the plane of the ethyl chain and the mean plane of 1,2,4-triazole ring is 88.55 (15)° and this conformation is stabilized by an intra-molecular C-H⋯S contact. In the crystal, pairs of N-H⋯S hydrogen bonds link mol-ecules into inversion dimers. π-π inter-actions are observed between the triazole and benzene rings, with centroid-centroid separations of 3.547 (4) and 3.544 (12) Å for components A and B, and slippages of 0.49 (6) and 0.58 (15) Å, respectively.

  19. Diallyl 5-[(4-hexyl-oxyphen-yl)imino-meth-yl]-m-phenyl-ene dicarbonate.

    Science.gov (United States)

    Herrera-González, Ana María; López-Velázquez, Delia; Bernès, Sylvain

    2009-10-23

    The title mol-ecule, C(27)H(31)NO(7), an imine derivative bearing both carbonate and allyl functionalities, was synthesized in the hope of obtaining a mesogenic polymerizable material. The allyl-carbonate arms are fully disordered over two sets of sites, reflecting a large degree of rotational freedom about σ bonds [occupancies: 0.665 (9)/0.335 (9) for one substituent, 0.564 (9)/0.436 (9) for the other]. In contrast, the hexyl chain is ordered, and presents the common all-trans extended conformation. The benzene rings connected via the imine group make a dihedral angle of 9.64 (11)°. In the crystal, the Y-shaped mol-ecules are weakly associated into centrosymmetric dimers through pairs of C-H⋯O(hex-yl) contacts. The resulting layers of dimers, approximately parallel to (25), are closely packed in the crystal, allowing π⋯π inter-actions between benzene rings of neighboring layers: the separation between the centroid of the benzene ring substituted by allyl-carbonate and the centroid of the benzene ring bearing the hex-yloxy group in the adjacent layer is 3.895 (1) Å.

  20. 4-(Prop-2-yn-1-ylsulfanyl-1H-pyrazolo[3,4-d]pyrimidine

    Directory of Open Access Journals (Sweden)

    Mohamed El Hafi

    2017-10-01

    Full Text Available The asymmetric unit of the title compound, C8H6N4S, consists of two independent molecules differing in the orientation of the side chain. In the crystal, molecules form dimers through N—H...N hydrogen bonds. The dimers stack along the a-axis direction with weak π–π stacking interactions [centroid–centroid distances of 3.898 (2 and 3.908 (2 Å]. The crystal studied was refined as a two-component twin.

  1. 2,2′-(Ethane-1,2-diylbis(1H-benzimidazole

    Directory of Open Access Journals (Sweden)

    Guo-Liang Zhao

    2012-05-01

    Full Text Available The complete molecule of the title compound, C16H14N4, is generated by crystallographic inversion symmetry. In the crystal, molecules are linked by N—H...N hydrogen bonds, generating (001 sheets. Weak aromatic π–π stacking interactions [centroid–centroid distances = 3.7383 (13 and 3.7935 (14 Å] are also observed.

  2. Dynamics of the off axis intense beam propagation in a spiral inflector

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, A., E-mail: animesh@vecc.gov.in; Sing Babu, P., E-mail: psb@vecc.gov.in; Pandit, V.S., E-mail: pandit@vecc.gov.in

    2017-01-01

    In this paper the dynamics of space charge dominated beam in a spiral inflector is discussed by developing equations of motion for centroid and beam envelope for the off axis beam propagation. Evolution of the beam centroid and beam envelope is studied as a function of the beam current for various input beam parameters. The transmission of beam through the inflector is also estimated as a function of the beam current for an on axis and off axis beam by tracking a large number of particles. Simulation studies show that shift of the centroid from the axis at the inflector entrance affects the centroid location at the exit of the inflector and causes reduction in the beam transmission. The centroid shift at the entrance in the horizontal plane (h plane) is more critical as it affects the centroid shift in the vertical plane (u plane) by a large amount near the inflector exit where the available aperture is small. The beam transmission is found to reduce with increase in the centroid shift as well as with the beam current.

  3. GALAXIES IN X-RAY GROUPS. II. A WEAK LENSING STUDY OF HALO CENTERING

    Energy Technology Data Exchange (ETDEWEB)

    George, Matthew R.; Ma, Chung-Pei [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Leauthaud, Alexie; Bundy, Kevin [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583 (Japan); Finoguenov, Alexis [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Rykoff, Eli S. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Tinker, Jeremy L. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Massey, Richard [Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Mei, Simona, E-mail: mgeorge@astro.berkeley.edu [Bureau des Galaxies, Etoiles, Physique, Instrumentation (GEPI), University of Paris Denis Diderot, F-75205 Paris Cedex 13 (France)

    2012-09-20

    Locating the centers of dark matter halos is critical for understanding the mass profiles of halos, as well as the formation and evolution of the massive galaxies that they host. The task is observationally challenging because we cannot observe halos directly, and tracers such as bright galaxies or X-ray emission from hot plasma are imperfect. In this paper, we quantify the consequences of miscentering on the weak lensing signal from a sample of 129 X-ray-selected galaxy groups in the COSMOS field with redshifts 0 < z < 1 and halo masses in the range 10{sup 13}-10{sup 14} M{sub Sun }. By measuring the stacked lensing signal around eight different candidate centers (such as the brightest member galaxy, the mean position of all member galaxies, or the X-ray centroid), we determine which candidates best trace the center of mass in halos. In this sample of groups, we find that massive galaxies near the X-ray centroids trace the center of mass to {approx}< 75 kpc, while the X-ray position and centroids based on the mean position of member galaxies have larger offsets primarily due to the statistical uncertainties in their positions (typically {approx}50-150 kpc). Approximately 30% of groups in our sample have ambiguous centers with multiple bright or massive galaxies, and some of these groups show disturbed mass profiles that are not well fit by standard models, suggesting that they are merging systems. We find that halo mass estimates from stacked weak lensing can be biased low by 5%-30% if inaccurate centers are used and the issue of miscentering is not addressed.

  4. k-Means: Random Sampling Procedure

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. k-Means: Random Sampling Procedure. Optimal 1-Mean is. Approximation of Centroid (Inaba et al). S = random sample of size O(1/ ); Centroid of S is a (1+ )-approx centroid of P with constant probability.

  5. Crystal structure of a looped-chain CoII coordination polymer: catena-poly[[bis(nitrato-κOcobalt(II]bis[μ-bis(pyridin-3-ylmethylsulfane-κ2N:N′

    Directory of Open Access Journals (Sweden)

    Suk-Hee Moon

    2017-11-01

    Full Text Available The asymmetric unit of the title compound, [Co(NO32(C12H12N2S2]n, contains a bis(pyridin-3-ylmethylsulfane (L ligand, an NO3− anion and half a CoII cation, which lies on an inversion centre. The CoII cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the CoII centre adopts a distorted octahedral geometry. Two symmetry-related L ligands are connected by two symmetry-related CoII cations, forming a 20-membered cyclic dimer, in which the CoII atoms are separated by 10.2922 (7 Å. The cyclic dimers are connected to each other by sharing CoII atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Intermolecular C—H...π (H...ring centroid = 2.89 Å interactions between one pair of corresponding L ligands and C—H...O hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by intermolecular π–π stacking interactions [centroid-to-centroid distance = 3.8859 (14 Å] and C—H...π hydrogen bonds (H...ring centroid = 2.65 Å, leading to the formation of layers parallel to (101. These layers are further connected through C—H...O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supramolecular architecture.

  6. Poly[(6-carboxypicolinato-κ3O2,N,O6(μ3-pyridine-2,6-dicarboxylato-κ5O2,N,O6:O2′:O6′dysprosium(III

    Directory of Open Access Journals (Sweden)

    Xu Li

    2009-11-01

    Full Text Available In the title complex, [Dy(C7H3NO4(C7H4NO4]n, one of the ligands is fully deprotonated while the second has lost only one H atom. Each DyIII ion is coordinated by six O atoms and two N atoms from two pyridine-2,6-dicarboxylate and two 6-carboxypicolinate ligands, displaying a bicapped trigonal-prismatic geometry. The average Dy—O bond distance is 2.40 Å, some 0.1Å longer than the corresponding Ho—O distance in the isotypic holmium complex. Adjacent DyIII ions are linked by the pyridine-2,6-dicarboxylate ligands, forming a layer in (100. These layers are further connected by π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.827 (3 Å] and C—H...O hydrogen-bonding interactions, assembling a three-dimensional supramolecular network. Within each layer, there are other π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.501 (2 Å] and O—H...O and C—H...O hydrogen-bonding interactions, which further stabilize the structure.

  7. Inter-Professional Collaboration in Action Research

    Science.gov (United States)

    Leeman, Yvonne; van Koeven, Erna; Schaafsma, Frank

    2018-01-01

    This article describes an example of inter-professional action research conducted by teachers and university-based researchers/teacher educators in a vocational college in the Netherlands. The research was aimed at the professional learning of the teachers on their pedagogical approach to a new curriculum initiative. Despite a difficult context in…

  8. 2,3-Diamino­pyridinium 6-carb­oxy­pyridine-2-carboxyl­ate

    Science.gov (United States)

    Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

    2011-01-01

    The asymmetric unit of the title proton-transfer compound, C5H8N3 +·C7H4NO4 −, consists of one mono-deprotonated pyridine-2,6-dicarb­oxy­lic acid as anion and one protonated 2,3-diamino­pyridine as cation. The crystal packing shows extensive O—H⋯O, N—H⋯O and N—H⋯N hydrogen bonds. Thre are also several π–π inter­actions between the anions and also between the cations [centriod–centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å]. PMID:22199823

  9. Generalized Centroid Estimators in Bioinformatics

    Science.gov (United States)

    Hamada, Michiaki; Kiryu, Hisanori; Iwasaki, Wataru; Asai, Kiyoshi

    2011-01-01

    In a number of estimation problems in bioinformatics, accuracy measures of the target problem are usually given, and it is important to design estimators that are suitable to those accuracy measures. However, there is often a discrepancy between an employed estimator and a given accuracy measure of the problem. In this study, we introduce a general class of efficient estimators for estimation problems on high-dimensional binary spaces, which represent many fundamental problems in bioinformatics. Theoretical analysis reveals that the proposed estimators generally fit with commonly-used accuracy measures (e.g. sensitivity, PPV, MCC and F-score) as well as it can be computed efficiently in many cases, and cover a wide range of problems in bioinformatics from the viewpoint of the principle of maximum expected accuracy (MEA). It is also shown that some important algorithms in bioinformatics can be interpreted in a unified manner. Not only the concept presented in this paper gives a useful framework to design MEA-based estimators but also it is highly extendable and sheds new light on many problems in bioinformatics. PMID:21365017

  10. 1-(3-Methoxyphenyl-2-(phenylsulfonylethan-1-one

    Directory of Open Access Journals (Sweden)

    Sammer Yousuf

    2012-08-01

    Full Text Available In the title compound, C15H14O4S, the dihedral angle between the benzene and phenyl rings is 88.74 (10°. In the crystal, molecules are linked into a three-dimensional network by C—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.6092 (13–3.8651 (13 Å].

  11. Crystal structure of 4-{2-[4-(dimethylaminophenyl]diazen-1-yl}-1-methylpyridinium iodide

    Directory of Open Access Journals (Sweden)

    Katherine Chulvi

    2015-12-01

    Full Text Available The molecular geometry of the ionic title compound, C14H17N4+·I− or DAZOP+·I−, is essentially featureless. Regarding the crystal structure, in addition to the obvious cation–anion Coulombic interactions, the packing is mostly directed by non-covalent interactions involving both ring systems, as well as the iodide anion. It consists of cationic molecules aligned along [101] and disposed in an antiparallel fashion while linked into π-bonded dimeric entities by a stacking contact involving symmetry-related phenyl rings, with a centroid–centroid distance of 3.468 (3 Å and a slippage of 0.951 Å. The dimers are, in addition, sustained by a number of C—H...I and I...π (I...centroid = 3.876 Å interactions involving the anion. Finally, interdimeric contacts are of the C—H...I and C—H...π types.

  12. Self-consistent study of space-charge-dominated beams in a misaligned transport system

    International Nuclear Information System (INIS)

    Sing Babu, P.; Goswami, A.; Pandit, V.S.

    2013-01-01

    A self-consistent particle-in-cell (PIC) simulation method is developed to investigate the dynamics of space-charge-dominated beams through a misaligned solenoid based transport system. Evolution of beam centroid, beam envelope and emittance is studied as a function of misalignment parameters for various types of beam distributions. Simulation results performed up to 40 mA of proton beam indicate that centroid oscillations induced by the displacement and rotational misalignments of solenoids do not depend of the beam distribution. It is shown that the beam envelope around the centroid is independent of the centroid motion for small centroid oscillation. In addition, we have estimated the loss of beam during the transport caused by the misalignment for various beam distributions

  13. Asymmetry in some common assignment algorithms: the dispersion factor solution

    OpenAIRE

    T de la Barra; B Pérez

    1986-01-01

    Many common assignment algorithms are based on Dial's original design to determine the paths that trip makers will follow from a given origin to destination centroids. The purpose of this paper is to show that the rules that have to be applied result in two unwanted properties. The first is that trips assigned from an origin centroid i to a destination j can be dramatically different to those resulting from centroid j to centroid i , even if the number of trips is the same and the network is ...

  14. Inter-layered clay stacks in Jurassic shales

    Science.gov (United States)

    Pye, K.; Krinsley, D. H.

    1983-01-01

    Scanning electron microscopy in the backscattered electron mode is used together with energy-dispersive X-ray microanalysis to show that Lower Jurassic shales from the North Sea Basin contain large numbers of clay mineral stacks up to 150 microns in size. Polished shale sections are examined to determine the size, shape orientation, textural relationships, and internal compositional variations of the clays. Preliminary evidence that the clay stacks are authigenic, and may have formed at shallow burial depths during early diagenesis, is presented.

  15. Reliability of an experimental method to analyse the impact point on a golf ball during putting.

    Science.gov (United States)

    Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

    2015-06-01

    This study aimed to examine the reliability of an experimental method identifying the location of the impact point on a golf ball during putting. Forty trials were completed using a mechanical putting robot set to reproduce a putt of 3.2 m, with four different putter-ball combinations. After locating the centre of the dimple pattern (centroid) the following variables were tested; distance of the impact point from the centroid, angle of the impact point from the centroid and distance of the impact point from the centroid derived from the X, Y coordinates. Good to excellent reliability was demonstrated in all impact variables reflected in very strong relative (ICC = 0.98-1.00) and absolute reliability (SEM% = 0.9-4.3%). The highest SEM% observed was 7% for the angle of the impact point from the centroid. In conclusion, the experimental method was shown to be reliable at locating the centroid location of a golf ball, therefore allowing for the identification of the point of impact with the putter head and is suitable for use in subsequent studies.

  16. Reliability analysis for manual radiographic measures of rotatory subluxation or lateral listhesis in adult scoliosis.

    Science.gov (United States)

    Freedman, Brett A; Horton, William C; Rhee, John M; Edwards, Charles C; Kuklo, Timothy R

    2009-03-15

    Retrospective observational study. To define the inter- and intraobserver reliability of 3 measures of rotatory subluxation (RS) in adult scoliosis (AS). RS is a hallmark of AS. To accurately track this measure, one must know its reliability. Reliability testing has not been performed. PA 36" films of 29 AS patients were collected from one surgeon's practice. Three observers on 2 separate occasions measured all levels with >or=3-mm RS (60 levels, 360 measurements) on the convexity of the involved segment using 3 different techniques-midbody (MB), endplate (EP), and centroid (C). These data were then analyzed to determine the intraclass correlation coefficient (ICC) for inter- and intraobserver reliability. The thoracolumbar/lumbar curve (average 58 degrees ) was the major curve for the majority (62%) of patients. RS at L3/4 was most common (35%). The overall inter- and intraobserver reliability was good-excellent for all methods, but the centroid method consistently had the highest ICC. ICC correlated with observer experience. Moderate-severe arthritic change (present in 55%) and poor image quality (52%) decreased ICC, but it still remained good-excellent for each measure. The reproducibility coefficient for each measure was 4 mm for MB and 2.8 mm for C and EP. MB, EP, and C are reliable techniques to measure RS even in elderly arthritic spines, but the methods inherently produce different values for a given level. The centroid method is most reliable and least influenced by experience. The EP method is easy to perform and very reliable. Spine surgeons should pick their preferred method and apply it consistently. Changes >3 mm suggest RS progression. RS may be a useful measure in addition to Cobb angle in AS. Having defined measurement reliability, the role of RS progression in surgical indications and patient outcomes can be evaluated.

  17. 4-(2-Fluoropyridin-5-ylphenol

    Directory of Open Access Journals (Sweden)

    Fazal Elahi

    2012-07-01

    Full Text Available In the title compound, C11H8FNO, the aromatic rings are oriented at a dihedral angle of 31.93 (6°. In the crystal, molecules are linked by O—H...N hydrogen bonds, forming C(9 chains propagating along the c-axis direction. There are aromatic π–π stacking interactions between the pyridine rings [centroid–centroid separation = 3.7238 (16 Å].

  18. Diiodido[methyl 2-(quinolin-8-yloxyacetate-κN]mercury(II

    Directory of Open Access Journals (Sweden)

    Yu-Hong Wang

    2012-08-01

    Full Text Available In the title mononuclear complex, [HgI2(C12H11NO3], the HgII ion has a distorted trigonal–planar coordination sphere defined by two I− anions and the N atom of a methyl 2-(quinolin-8-yloxyacetate ligand. In the crystal, face-to-face π–π stacking interactions, with a centroid–centroid distance of 3.563 (9 Å, are observed.

  19. 2-(1,3-Dioxoisoindolin-2-ylacetic acid–N′-[(E-2-methoxybenzylidene]pyridine-4-carbohydrazide (1/1

    Directory of Open Access Journals (Sweden)

    Shaaban K. Mohamed

    2012-08-01

    Full Text Available In the title 1:1 cocrystal, C10H7NO4·C14H13N3O2, molecules are linked by intermolecular C—H...O, N—H...O and O—H...N hydrogen bonds, forming a three-dimensional network. In addition, π–π stacking interactions [with centroid–centroid distances of 3.5723 (19 and 3.6158 (18 Å] are observed.

  20. Cylinder gauge measurement using a position sensitive detector

    International Nuclear Information System (INIS)

    St John, W. Doyle

    2007-01-01

    A position sensitive detector (PSD) has been used to determine the diameter of cylindrical pins based on the shift in a laser beam's centroid. The centroid of the light beam is defined here as the weighted average of position by the local intensity. A shift can be observed in the centroid of an otherwise axially symmetric light beam, which is partially obstructed. Additionally, the maximum shift in the centroid is a unique function of the obstructing cylinder diameter. Thus to determine the cylinder diameter, one only needs to detect this maximum shift as the cylinder is swept across the beam

  1. Ethyl 13-(4-chlorophenyl-11-methyl-6-oxo-5-phenyl-8-thia-3,4,5,10-tetraazatricyclo[7.4.0.02,7]trideca-1(9,2(7,3,10,12-pentaene-12-carboxylate

    Directory of Open Access Journals (Sweden)

    Elham A. Al-Taifi

    2016-05-01

    Full Text Available In the title molecule, C24H17ClN4O3S, the central tricyclic moiety is twisted slightly, as indicated by the dihedral angles of 4.86 (5 and 0.97 (6°, respectively, between the five-membered ring and the C3N3 and pyridyl rings. Additionally, the chlorobenzene ring makes a dihedral angle of 65.80 (5° with the pyridyl ring. Weak C—H...O, C—Cl...N [3.0239 (13 Å] and π–π stacking interactions [inter-centroid distance between thienyl rings = 3.6994 (8 Å, and between thienyl and pyridyl rings = 3.7074 (8 Å] contribute to the molecular packing. The ethyl group in the ester moiety is disordered over two sets of sites, with the major component having an occupancy of 0.567 (11.

  2. Crystal structure of 2-hydroxyimino-2-(pyridin-2-yl-N′-[1-(pyridin-2-ylethylidene]acetohydrazide

    Directory of Open Access Journals (Sweden)

    Maxym O. Plutenko

    2014-12-01

    Full Text Available The molecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å, with the planes of the two pyridine rings inclined to one another by 5.51 (7°. The oxime group is syn to the amide group, probably due to the formation of an intramolecular N—H...N hydrogen bond that forms an S(6 ring motif. In the crystal, molecules are linked by pairs of bifurcated O—H...(O,N hydrogen bonds, forming inversion dimers. The latter are linked via C—H...O and C—H...N hydrogen bonds, forming sheets lying parallel to (502. The sheets are linked via π–π stacking interactions [inter-centroid distance = 3.7588 (9 Å], involving the pyridine rings of inversion-related molecules, forming a three-dimensional structure.

  3. (4-Nitrophenylmethyl 2,3-dihydro-1H-pyrrole-1-carboxylate: crystal structure and Hirshfeld analysis

    Directory of Open Access Journals (Sweden)

    Julio Zukerman-Schpector

    2018-03-01

    Full Text Available In the title compound, C12H12N2O4, the dihydropyrrole ring is almost planar (r.m.s. deviation = 0.0049 Å and is nearly coplanar with the adjacent C2O2 residue [dihedral angle = 4.56 (9°], which links to the 4-nitrobenzene substituent [dihedral angle = 4.58 (8°]. The molecule is concave, with the outer rings lying to the same side of the central C2O2 residue and being inclined to each other [dihedral angle = 8.30 (7°]. In the crystal, supramolecular layers parallel to (10-5 are sustained by nitrobenzene-C—H...O(carbonyl and pyrrole-C—H...O(nitro interactions. The layers are connected into a three-dimensional architecture by π(pyrrole–π(nitrobenzene stacking [inter-centroid separation = 3.7414 (10 Å] and nitro-O...π(pyrrole interactions.

  4. 3-(Aminocarbonylpyridinium diaqua-bis(pyridine-2,6-dicarboxylatobismuthate(III monohydrate

    Directory of Open Access Journals (Sweden)

    Janet Soleimannejad

    2012-07-01

    Full Text Available The asymmetric unit of the ionic title compound, (C6H7N2O[Bi(C7H3NO42(H2O2]·H2O or (acpyH[Bi(pydc2(H2O2]·H2O, contains an [Bi(pydc2(H2O2]− anion (where pydcH2 is pyridine-2,6-dicarboxylic acid, a protonated 3-(aminocarbonylpyridine as counter-ion, (acpyH+, and one uncoordinated water molecule. The anion is an eight-coordinate complex with a square-antiprismatic geometry around the BiIII atom. In the crystal, extensive O—H...O and N—H...O hydrogen bonds, as well as ion pairing, C=O...π interactions [O...centroid distance = 3.583 (5 Å], π–π stacking [centroid–centroid distance = 3.864 (3 Å], and C—H...π and C—H...O interactions, play an important role in the formation and stabilization of the three-dimensional supramolecular structure.

  5. (E-1-Methyl-4-[2-(2-naphthylvinyl]pyridinium iodideThis paper is dedicated to the late Her Royal Highness Princess Galyani Vadhana Krom Luang Naradhiwas Rajanagarindra for her patronage of Science in Thailand.

    Directory of Open Access Journals (Sweden)

    Hoong Kun Fun

    2009-06-01

    Full Text Available In the title compound, C18H16N+·I−, the cation is disordered over two orientations related by a 180° rotation about its long axis with occupancies of 0.554 (7 and 0.446 (7. Both disorder components exist in an E configuration. The dihedral angle between the pyridinium ring and the naphthalene ring system is 4.7 (6° in the major disorder component and 1.6 (8° in the minor component. In the crystal structure, centrosymmetrically related cations are stacked along the a axis, with significant π–π interactions between the pyridinium ring and the naphthalene ring system [centroid-centroid distance = 3.442 (9 Å]. The iodide ions are located between adjacent columns of cations. The cations are linked to the iodide ions by C—H...I interactions. Weak C—H...π interactions involving the methyl group are also observed.

  6. 1,3-Bis(chloromethyl-2-methyl-5-nitrobenzene

    Directory of Open Access Journals (Sweden)

    Chang-Yun Wang

    2008-04-01

    Full Text Available The title compound, C9H9Cl2NO2, is a natural product isolated from the endophytic fungus No. B77 of the mangrove tree from the South China Sea coast. In the crystal structure, the molecules lie on twofold axes and form offset stacks through face-to-face π–π interactions. Adjacent molecules in each stack are related by a centre of inversion and have an interplanar separation of 3.53 (1 Å, with a centroid–centroid distance of 3.76 (1 Å. Between stacks, there are C—H...O interactions to the nitro groups and Cl...Cl contacts of 3.462 (1 Å.

  7. Beam-Based Alignment of Magnetic Field in the Fermilab Electron Cooler Cooling Section

    International Nuclear Information System (INIS)

    Seletskiy, S. M.; Tupikov, V.

    2006-01-01

    The Fermilab Electron Cooling Project requires low effective anglular spread of electrons in the cooling section. One of the main components of the effective electron angles is an angle of electron beam centroid with respect to antiproton beam. This angle is caused by the poor quality of magnetic field in the 20 m long cooling section solenoid and by the mismatch of the beam centroid to the entrance of the cooling section. This paper focuses on the beam-based procedure of the alignment of the cooling section field and beam centroid matching. The discussed procedure allows to suppress the beam centroid angles below the critical value of 0.1 mrad

  8. 3-Methyl-1-(prop-2-en-1-ylquinoxalin-2(1H-one

    Directory of Open Access Journals (Sweden)

    Youssef Ramli

    2010-07-01

    Full Text Available In the molecule of the title compound, C12H12N2O, the quinoxaline ring is planar with an r.m.s. deviation of 0.007 (15 Å. The dihedral angle between the quinoxaline and propenyl planes is 82.1 (2°. The crystal packing is stabilized by offset π–π stacking between the quinoxaline rings [centroid–centroid distance = 3.8832 (9 Å].

  9. 4,5-Bis(isopropylsulfanylbenzene-1,2-dicarbonitrile

    Directory of Open Access Journals (Sweden)

    Xingcui Wu

    2010-04-01

    Full Text Available In the title compound, C14H16N2S2, the C atoms of the aromatic ring, the two cyanide groups and the two S atoms of the isopropylsulfanyl groups are almost coplanar [maximum deviation from the mean plane = 0.042 (7 Å]. In the crystal, inversion dimers linked by aromatic π–π stacking occur, with a centroid–centroid separation of 3.7543 (8 Å.

  10. 5-Diethylamino-2-[(E-(2,4-dimethoxyphenyliminomethyl]phenol

    Directory of Open Access Journals (Sweden)

    Esen Nur Kantar

    2012-06-01

    Full Text Available The title Schiff base, C19H24N2O3, exists in the crystal structure in the phenol–imine tautomeric form with an intramolecular O—H...N hydrogen bond. The planes of the aromatic rings form a dihedral angle of 36.8 (8°. The crystal packing is characterized by C—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.478 (4Å].

  11. Equilibrium and stability of off-axis periodically focused particle beams

    International Nuclear Information System (INIS)

    Moraes, J.S.; Pakter, R.; Rizzato, F.B.

    2004-01-01

    A general equation for the centroid motion of free, continuous, intense beams propagating off axis in solenoidal periodic focusing fields is derived. The centroid equation is found to be independent of the specific beam distribution and may exhibit unstable solutions. A new Vlasov equilibrium for off-axis beam propagation is also obtained. The properties of the equilibrium and the relevance of centroid motion to beam confinement are discussed

  12. Investigation of the Relationship Between Gross Tumor Volume Location and Pneumonitis Rates Using a Large Clinical Database of Non-Small-Cell Lung Cancer Patients

    International Nuclear Information System (INIS)

    Vinogradskiy, Yevgeniy; Tucker, Susan L.; Liao Zhongxing; Martel, Mary K.

    2012-01-01

    Purpose: Studies have suggested that function may vary throughout the lung, and that patients who have tumors located in the base of the lung are more susceptible to radiation pneumonitis. The purpose of our study was to investigate the relationship between gross tumor volume (GTV) location and pneumonitis rates using a large clinical database of 547 patients with non–small-cell lung cancer. Methods and Materials: The GTV centroids of all patients were mapped onto one common coordinate system, in which the boundaries of the coordinate system were defined by the extreme points of each individual patient lung. The data were qualitatively analyzed by graphing all centroids and displaying the data according to the presence of severe pneumonitis, tumor stage, and smoking status. The centroids were grouped according to superior–inferior segments, and the pneumonitis rates were analyzed. In addition, we incorporated the GTV centroid information into a Lyman–Kutcher–Burman normal tissue complication probability model and tested whether adding spatial information significantly improved the fit of the model. Results: Of the 547 patients analyzed, 111 (20.3%) experienced severe radiation pneumonitis. The pneumonitis incidence rates were 16%, 23%, and 21% for the superior, middle, and inferior thirds of the lung, respectively. Qualitatively, the GTV centroids of nonsmokers were notably absent from the superior portion of the lung. In addition, the GTV centroids of patients who had Stage III and IV clinical staging were concentrated toward the medial edge of the lung. The comparison between the GTV centroid model and the conventional dose–volume model did not yield a statistically significant difference in model fit. Conclusions: Lower pneumonitis rates were noted for the superior portion of the lung; however the differences were not statistically significant. For our patient cohort, incorporating GTV centroid information did not lead to a statistically significant

  13. Investigation of the relationship between gross tumor volume location and pneumonitis rates using a large clinical database of non-small-cell lung cancer patients.

    Science.gov (United States)

    Vinogradskiy, Yevgeniy; Tucker, Susan L; Liao, Zhongxing; Martel, Mary K

    2012-04-01

    Studies have suggested that function may vary throughout the lung, and that patients who have tumors located in the base of the lung are more susceptible to radiation pneumonitis. The purpose of our study was to investigate the relationship between gross tumor volume (GTV) location and pneumonitis rates using a large clinical database of 547 patients with non-small-cell lung cancer. The GTV centroids of all patients were mapped onto one common coordinate system, in which the boundaries of the coordinate system were defined by the extreme points of each individual patient lung. The data were qualitatively analyzed by graphing all centroids and displaying the data according to the presence of severe pneumonitis, tumor stage, and smoking status. The centroids were grouped according to superior-inferior segments, and the pneumonitis rates were analyzed. In addition, we incorporated the GTV centroid information into a Lyman-Kutcher-Burman normal tissue complication probability model and tested whether adding spatial information significantly improved the fit of the model. Of the 547 patients analyzed, 111 (20.3%) experienced severe radiation pneumonitis. The pneumonitis incidence rates were 16%, 23%, and 21% for the superior, middle, and inferior thirds of the lung, respectively. Qualitatively, the GTV centroids of nonsmokers were notably absent from the superior portion of the lung. In addition, the GTV centroids of patients who had Stage III and IV clinical staging were concentrated toward the medial edge of the lung. The comparison between the GTV centroid model and the conventional dose-volume model did not yield a statistically significant difference in model fit. Lower pneumonitis rates were noted for the superior portion of the lung; however the differences were not statistically significant. For our patient cohort, incorporating GTV centroid information did not lead to a statistically significant improvement in the fit of the pneumonitis model. Copyright

  14. The influence of image sensor irradiation damage on the tracking and pointing accuracy of optical communication system

    Science.gov (United States)

    Li, Xiaoliang; Luo, Lei; Li, Pengwei; Yu, Qingkui

    2018-03-01

    The image sensor in satellite optical communication system may generate noise due to space irradiation damage, leading to deviation for the determination of the light spot centroid. Based on the irradiation test data of CMOS devices, simulated defect spots in different sizes have been used for calculating the centroid deviation value by grey-level centroid algorithm. The impact on tracking & pointing accuracy of the system has been analyzed. The results show that both the amount and the position of irradiation-induced defect pixels contribute to spot centroid deviation. And the larger spot has less deviation. At last, considering the space radiation damage, suggestions are made for the constraints of spot size selection.

  15. Action research in inter-organisational networks : - impartial studies or the Trojan horse?

    DEFF Research Database (Denmark)

    Goduscheit, René Chester; Rasmussen, Erik Stavnsager; Jørgensen, Jacob Høj

    2007-01-01

    Traditionally, the literature on action research has been aimed at intra-organisational issues. These studies have distinguished between two researcher roles: The problem-solver and the observer. This article addresses the distinct challenges of action research in inter-organisational projects....... In addition to the problem-solver and observer roles, the researcher in an inter-organisational setting can serve as a legitimiser of the project and manage to involve partners that in an ordinary business-to-business setting would not have participated. Based on an action research project in a Danish inter......-organisational network, this article discusses potential pitfalls in the legitimiser role. Lack of clarity in defining the researcher role and project ownership in relation to the funding organisation and the rest of the network can jeopardise the project and potentially the credibility of the researchers. The article...

  16. (Carbonyl-1κC)bis-[2,3(η)-cyclo-penta-dien-yl][μ(3)-(S-methyl trithio-carbonato)methylidyne-1:2:3κC,S'':C:C](triphenyl-phosphine-1κP)(μ(3)-sulfido-1:2:3κS)dicobalt(II)iron(II) trifluoro-methane-sulfonate.

    Science.gov (United States)

    Manning, Anthony R; McAdam, C John; Palmer, Anthony J; Simpson, Jim

    2008-04-10

    The asymmetric unit of the title compound, [FeCo(2)(C(5)H(5))(2)(C(3)H(3)S(3))S(C(18)H(15)P)(CO)]CF(3)SO(3), consists of a triangular irondicobalt cluster cation and a trifluoro-methane-sulfonate anion. In the cation, the FeCo(2) triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio-carbonate residue that bridges the Fe-C bond. Each Co atom carries a cyclo-penta-dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl-phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C-H⋯O and C-H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter-actions. The structure is further stabilized by additional inter-molecular C-H⋯O, C-H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter-action (S⋯centroid distance = 3.385 Å), generating an extended network.

  17. 3H-1,2-Benzodithiole-3-thione

    Directory of Open Access Journals (Sweden)

    Khaled Boukebbous

    2016-10-01

    Full Text Available The almost planar (r.m.s. deviation = 0.034 Å title compound, C7H4S3, was synthesized by reacting 2,2-dithiodibenzoic acid with phosphorus pentasulfide in xylene solution. In the crystal, short S...S [3.3727 (14, 3.3765 (13 and 3.4284 (13 Å] contacts and aromatic π–π stacking [shortest centroid–centroid separation = 3.618 (2 Å] are observed.

  18. Ethyl 2-cyano-5-oxo-5-(thiophen-2-yl-3-(3,4,5-trimethoxyphenylpentanoate

    Directory of Open Access Journals (Sweden)

    M. Prabhuswamy

    2012-12-01

    Full Text Available In the title compound, C21H23NO6S, the dihedral angle between the thiopene and benzene rings is 88.66 (6°. In the crystal, molecules are connected by C—H...N and C—H...O hydrogen bonds, forming a tape along [10-1]. In addition, C—H...π and π–π stacking [centroid–centroid distance = 3.879 (2 Å between the thiophene rings] interactions are observed.

  19. (2-Pyridyl[5-(2-pyridylcarbonyl-2-pyridyl]methanone

    Directory of Open Access Journals (Sweden)

    Zi-jia Wang

    2010-10-01

    Full Text Available In the centrosymmetric title compound, C17H11N3O2, the dihedral angle between the central and pendant pyridyl rings is 50.29 (9°. In the crystal, molecules stack along the a axis by π–π interactions between the pyridine rings with centroid–centroid distances of 3.845 (2 Å. The N atom and one of the C atoms of the central ring are disordered by symmetry.

  20. Theoretical Predictions of Giant Resonances in 94Mo

    Science.gov (United States)

    Golden, Matthew; Bonasera, Giacomo; Shlomo, Shalom

    2016-09-01

    We perform Hartree-Fock based Random Phase Approximation using thirty-three common Skyrme interactions found in the literature for 94Mo. We calculate the strength functions and the Centroid Energies of the Isoscalar Giant Resonances for all multipolarities L0, L1, L2, L3. We compare the calculated Centroid Energies with the experimental value; we also study the Centroid Energy and any correlation it may have with the Nuclear Matter properties of each interaction.

  1. Observational Evidence for the Effect of Amplification Bias in Gravitational Microlensing Experiments

    Science.gov (United States)

    Han, Cheongho; Jeong, Youngjin; Kim, Ho-Il

    1998-11-01

    Recently Alard, Mao, & Guibert and Alard proposed to detect the shift of a star's image centroid, δx, as a method to identify the lensed source among blended stars. Goldberg & Woźniak actually applied this method to the OGLE-1 database and found that seven of 15 events showed significant centroid shifts of δx >~ 0.2". The amount of centroid shift has been estimated theoretically by Goldberg; however, he treated the problem in general and did not apply it to a particular survey or field and therefore based his estimate on simple toy model luminosity functions (i.e., power laws). In this paper, we construct the expected distribution of δx for Galactic bulge events based on the precise stellar luminosity function observed by Holtzman et al. using the Hubble Space Telescope. Their luminosity function is complete up to MI ~ 9.0 (MV ~ 12), which corresponds to faint M-type stars. In our analysis we find that regular blending cannot produce a large fraction of events with measurable centroid shifts. By contrast, a significant fraction of events would have measurable centroid shifts if they are affected by amplification-bias blending. Therefore, the measurements of large centroid shifts for an important fraction of microlensing events of Goldberg & Woźniak confirm the prediction of Han & Alard that a large fraction of Galactic bulge events are affected by amplification-bias blending.

  2. 2-Oxo-2H-chromen-7-yl 4-tert-butylbenzoate

    Directory of Open Access Journals (Sweden)

    Mohammad Ouédraogo

    2018-04-01

    Full Text Available In the title compound, C20H18O4, the benzoate ring is oriented at an acute angle of 33.10 (12° with respect to the planar (r.m.s deviation = 0.016 Å coumarin ring system. An intramolecular C—H...O hydrogen bond closes an S(6 ring motif. In the crystal, C—H...O contacts generate infinite C(6 chains along the b-axis direction. Also present are π–π stacking interactions between neighbouring pyrone and benzene rings [centroid–centroid distance = 3.7034 (18 Å] and C=O...π interactions [O...centroid = 3.760 (3 Å]. The data obtained from quantum chemical calculations performed on the title compound are in good agreement with the observed structure, although the calculated C—O—C—C torsion angle between the coumarin ring system and the benzoate ring (129.1° is somewhat lower than the observed value [141.3 (3°]. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.

  3. Crystal structure of catena-poly[1,3-dibenzylbenzimidazolium [[chloridomercurate(II]-di-μ-chlorido

    Directory of Open Access Journals (Sweden)

    Mehdi Bouchouit

    2015-12-01

    Full Text Available The asymmetric unit of the polymeric title compound, {(C21H19N2[HgCl3]}n, comprises one-half of the cationic molecule, the other half being generated by application of twofold rotation symmetry, one Hg and two Cl atoms. The HgII atom, lying on a twofold rotation axis, exhibits a distorted triangular coordination environment and is surrounded by three Cl atoms with Hg—Cl distances in the range 2.359 (2–2.4754 (13 Å. Two additional longer distances [Hg...Cl = 3.104 (14 Å] lead to the formation of polymeric [HgCl1/1Cl4/2]− chains extending along [001]. The crystal packing can be described by cationic layers alternating parallel to (-110 with the anionic chains located between the layers. The packing is consolidated by π–π stacking interactions between the benzene rings of the central benzimidazole entities, with centroid-to-centroid distances of 3.643 (3 Å.

  4. Aqua(4-hydroxypyridine-2,6-dicarboxylato(1,10-phenanothrolinecopper(II 4.5-hydrate

    Directory of Open Access Journals (Sweden)

    Hossein Aghabozorg

    2008-01-01

    Full Text Available The title compound, [Cu(C7H3NO5(C12H8N2(H2O]·4.5H2O or [Cu(hypydc(phen(H2O]·4.5H2O (phen is 1,10-phenanthroline and hypydcH2 is 4-hydroxypyridine-2,6-dicarboxylic acid, was obtained by the reaction of copper(II nitrate hexahydrate with the proton-transfer compound (phenH2(hypydc in aqueous solution. Both the cationic and the anionic fragments of the proton-transfer compound are involved in complexation. Each CuII atom has a distorted octahedral geometry. It is hexacoordinated by three O atoms and three N atoms, from one phen fragment (as bidentate ligand, one (hypydc2− unit (as tridentate ligand and a water molecule. In the crystal structure, O—H...O and C—H...O hydrogen bonds, and π–π stacking interactions [centroid-to-centroid distance 3.5642 (11 Å] between the phen ring systems, contribute to the formation of a three-dimensional supramolecular structure.

  5. Cf-252 based neutron radiography using real-time image processing system

    International Nuclear Information System (INIS)

    Mochiki, Koh-ichi; Koiso, Manabu; Yamaji, Akihiro; Iwata, Hideki; Kihara, Yoshitaka; Sano, Shigeru; Murata, Yutaka

    2001-01-01

    For compact Cf-252 based neutron radiography, a real-time image processing system by particle counting technique has been developed. The electronic imaging system consists of a supersensitive imaging camera, a real-time corrector, a real-time binary converter, a real-time calculator for centroid, a display monitor and a computer. Three types of accumulated NR image; ordinary, binary and centroid images, can be observed during a measurement. Accumulated NR images were taken by the centroid mode, the binary mode and ordinary mode using of Cf-252 neutron source and those images were compared. The centroid mode presented the sharpest image and its statistical characteristics followed the Poisson distribution, while the ordinary mode showed the smoothest image as the averaging effect by particle bright spots with distributed brightness was most dominant. (author)

  6. On the effects of rotation on interstellar molecular line profiles

    International Nuclear Information System (INIS)

    Adelson, L.M.; Chunming Leung

    1988-01-01

    Theoretical models are constructed to study the effects of systematic gas rotation on the emergent profiles of interstellar molecular lines, in particular the effects of optical depth and different velocity laws. Both rotational and radial motions (expansion or contraction) may produce similar asymmetric profiles, but the behaviour of the velocity centroid of the emergent profile over the whole cloud (iso-centroid maps) can be used to distinguish between these motions. Iso-centroid maps can also be used to determine the location and orientation of the rotation axis and of the equatorial axis. For clouds undergoing both radial and rotational motion, the component of the centroid due to the rotational motion can be separated from that due to the radial motion. Information on the form of the rotational velocity law can also be derived. (author)

  7. Crystal structure of 2-(adamantan-1-yl-5-(4-bromophenyl-1,3,4-oxadiazole

    Directory of Open Access Journals (Sweden)

    Nourah Z. Alzoman

    2014-12-01

    Full Text Available In the title molecule, C18H19BrN2O, the benzene ring is inclined to the oxadiazole ring by 10.44 (8°. In the crystal, C—H...π interactions link the molecules in a head-to-tail fashion, forming chains extending along the c-axis direction. The chains are further connected by π–π stacking interactions, with centroid–centroid distances of 3.6385 (7 Å, forming layers parallel to the bc plane.

  8. 6,8-Dibromoquinoline

    Directory of Open Access Journals (Sweden)

    Ísmail Çelik

    2010-11-01

    Full Text Available The title molecule, C9H5Br2N, is almost planar, with an r.m.s. deviation of 0.027 Å. The dihedral angle between the aromatic rings is 1.5 (3°. In the crystal, π–π stacking interactions are present between the pyridine and benzene rings of adjacent molecules [centroid–centroid distances = 3.634 (4 Å], and short Br...Br contacts [3.4443 (13 Å] occur.

  9. 2-(7-Methoxy-1-naphthylacetonitrile

    Directory of Open Access Journals (Sweden)

    Wen-bin Wei

    2010-07-01

    Full Text Available The molecule of the title compound, C13H11NO, is almost planar (r.m.s. deviation = 0.013 Å, apart from the cyanide group, for which the C and N atoms deviate from the mean plane of the other atoms by 0.341 (3 and 0.571 (4 Å, respectively. In the crystal, weak aromatic π–π stacking [centroid–centroid distance = 3.758 (3 Å] may help to stabilize the structure.

  10. Dibromido(6-methyl-2,2′-bipyridine-κ2N,N′zinc(II

    Directory of Open Access Journals (Sweden)

    Vahid Amani

    2010-10-01

    Full Text Available In the title compound, [ZnBr2(C11H10N2], the ZnII atom is four-coordinated in a distorted tetrahedral configuration by two N atoms from a 6-methyl-2,2′-bipyridine ligand and two terminal Br atoms. Weak intermolecular C—H...Br hydrogen bonds and π–π stacking interactions between the pyridine rings [centroid–centroid distances = 3.763 (5 and 3.835 (6 Å] contribute to crystal-packing effects.

  11. Hose-Modulation Instability of Laser Pulses in Plasmas

    International Nuclear Information System (INIS)

    Sprangle, P.; Krall, J.; Esarey, E.

    1994-01-01

    A laser pulse propagating in a uniform plasma or a preformed plasma density channel is found to undergo a combination of hose and modulation instabilities, provided the pulse centroid has an initial tilt. Coupled equations for the laser centroid and envelope are derived and solved for a finite-length laser pulse. Significant coupling between the centroid and the envelope, harmonic generation in the envelope, and strong modification of the wake field can occur. Methods to reduce the growth rate of the laser hose instability are demonstrated

  12. Cluster analysis of received constellations for optical performance monitoring

    NARCIS (Netherlands)

    van Weerdenburg, J.J.A.; van Uden, R.; Sillekens, E.; de Waardt, H.; Koonen, A.M.J.; Okonkwo, C.

    2016-01-01

    Performance monitoring based on centroid clustering to investigate constellation generation offsets. The tool allows flexibility in constellation generation tolerances by forwarding centroids to the demapper. The relation of fibre nonlinearities and singular value decomposition of intra-cluster

  13. Statistical properties of antisymmetrized molecular dynamics for non-nucleon-emission and nucleon-emission processes

    International Nuclear Information System (INIS)

    Ono, A.; Horiuchi, H.

    1996-01-01

    Statistical properties of antisymmetrized molecular dynamics (AMD) are classical in the case of nucleon-emission processes, while they are quantum mechanical for the processes without nucleon emission. In order to understand this situation, we first clarify that there coexist mutually opposite two statistics in the AMD framework: One is the classical statistics of the motion of wave packet centroids and the other is the quantum statistics of the motion of wave packets which is described by the AMD wave function. We prove the classical statistics of wave packet centroids by using the framework of the microcanonical ensemble of the nuclear system with a realistic effective two-nucleon interaction. We show that the relation between the classical statistics of wave packet centroids and the quantum statistics of wave packets can be obtained by taking into account the effects of the wave packet spread. This relation clarifies how the quantum statistics of wave packets emerges from the classical statistics of wave packet centroids. It is emphasized that the temperature of the classical statistics of wave packet centroids is different from the temperature of the quantum statistics of wave packets. We then explain that the statistical properties of AMD for nucleon-emission processes are classical because nucleon-emission processes in AMD are described by the motion of wave packet centroids. We further show that when we improve the description of the nucleon-emission process so as to take into account the momentum fluctuation due to the wave packet spread, the AMD statistical properties for nucleon-emission processes change drastically into quantum statistics. Our study of nucleon-emission processes can be conversely regarded as giving another kind of proof of the fact that the statistics of wave packets is quantum mechanical while that of wave packet centroids is classical. copyright 1996 The American Physical Society

  14. Action Research in Inter-organisational Networks - Impartial studies or the Trojan Horse?

    DEFF Research Database (Denmark)

    Goduscheit, René Chester; Bergenholtz, Carsten; Jørgensen, Jacob Høj

    2008-01-01

    Traditionally, the literature on action research has been aimed at intra-organisational issues. These studies have distinguished between two researcher roles: The problem-solver and the observer. This article addresses the distinct challenges of action research in inter-organisational projects. I...

  15. Distributed formation tracking using local coordinate systems

    DEFF Research Database (Denmark)

    Yang, Qingkai; Cao, Ming; Garcia de Marina, Hector

    2018-01-01

    This paper studies the formation tracking problem for multi-agent systems, for which a distributed estimator–controller scheme is designed relying only on the agents’ local coordinate systems such that the centroid of the controlled formation tracks a given trajectory. By introducing a gradient...... descent term into the estimator, the explicit knowledge of the bound of the agents’ speed is not necessary in contrast to existing works, and each agent is able to compute the centroid of the whole formation in finite time. Then, based on the centroid estimation, a distributed control algorithm...

  16. Dual affine isoperimetric inequalities

    Directory of Open Access Journals (Sweden)

    Bin Xiong

    2006-01-01

    Full Text Available We establish some inequalities for the dual -centroid bodies which are the dual forms of the results by Lutwak, Yang, and Zhang. Further, we establish a Brunn-Minkowski-type inequality for the polar of dual -centroid bodies.

  17. Dicyclo-hexyl-ammonium 3,5-dinitro-benzoate.

    Science.gov (United States)

    Saeed, Sohail; Rashid, Naghmana; Hussain, Rizwan; Wong, Wing-Tak

    2012-07-01

    The asymmetric unit of the title salt, C(12)H(24)N(+)·C(7)H(3)N(2)O(6) (-), contains two cations and two anions. In the crystal, the cations and anions are connected by N-H⋯O hydrogen bonds, forming a 12-membered ring with an R(4) (4)(12) graph-set motif. The center of this 12-membered ring coincides with an inversion centre. π-π stacking is observed between parallel benzene rings [centroid-centriod distance = 3.771 (2) Å].

  18. 2-(1H-Imidazol-1-yl)-3-isopropyl-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

    OpenAIRE

    Xu, Sheng-Zhen

    2007-01-01

    In the title compound, C16H14N4OS, the three fused rings of the benzothieno[3,2-d]pyrimidinone unit are essentially coplanar, the maximum deviation from the mean plane being 0.067 (3) Å. The dihedral angle between the mean plane of the fused rings and the imidazole ring is 72.00 (3)°. Offset π–π stacking interactions involving the fused rings are effective in the stabilization of the crystal structure. The centroid–centroid distances between t...

  19. (2,2′-Bipyridine-κ2N,N′iodido(piperidine-1-carbodithioato-κ2S,S′copper(II

    Directory of Open Access Journals (Sweden)

    Le-Qing Fan

    2009-01-01

    Full Text Available In the title compound, [Cu(C6H10NS2I(C10H8N2], the CuII ion is coordinated by one iodide ion, two N atoms of the bipyridine ligand and two S atoms from the piperidinecarbodithioate ligand in a distorted square-pyramidal environment. π–π stacking interactions, with centroid–centroid distances of 3.643 (4 Å, between pyridyl rings of the bipyridyl ligands of neighbouring molecules lead to chains propagating parallel to the a axis.

  20. 5-Methylbenzo[d][2,1,3]selenadiazole

    Directory of Open Access Journals (Sweden)

    Halima Ouahine

    2017-02-01

    Full Text Available In the crystal of the title compound, C7H6N2Se, the molecules are arranged in rods along the b-axis direction and form dimeric units due to intermolecular Se...N contacts of 2.982 (2 Å. The molecules are further linked by weak π–π stacking interactions between the 2,1,3-selenadiazole and six-membered aromatic rings [centroid–centroid distance = 3.8509 (11 Å and ring slippage = 1.539 (3 Å].

  1. 2-Isopropyl-4,7-dimethyl-1-nitronaphthalene

    Directory of Open Access Journals (Sweden)

    Ahmed Benharref

    2017-04-01

    Full Text Available All the non-H atoms of the title compound, C15H17NO2, except the CH3 groups of the isopropyl unit and the O atoms of the nitro group, lie on a crystallographic mirror plane. The dihedral angle between the naphthalene plane and the nitro group is constrained to be 90° by symmetry. In the crystal, molecules are linked by π–π interactions [centroid–centroid separation = 3.6591 (4 Å] and stacked along the b-axis direction.

  2. Bis(μ-carboxylatoethylphosphonatobis[aqua(2,2′-bipyridinemanganese(II

    Directory of Open Access Journals (Sweden)

    Shao-Ming Ying

    2008-01-01

    Full Text Available The title compound, [Mn2(HO3PCH2CH2COO2(C8H8N22(H2O2], was obtained by hydrothermal synthesis. The manganese(II ions are six-coordinate and are linked by two 2-carboxyethylphosphonate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distance 4.2754 (4 Å].

  3. Seismicity in the block mountains between Halle and Leipzig, Central Germany: centroid moment tensors, ground motion simulation, and felt intensities of two M ≈ 3 earthquakes in 2015 and 2017

    Science.gov (United States)

    Dahm, Torsten; Heimann, Sebastian; Funke, Sigward; Wendt, Siegfried; Rappsilber, Ivo; Bindi, Dino; Plenefisch, Thomas; Cotton, Fabrice

    2018-05-01

    On April 29, 2017 at 0:56 UTC (2:56 local time), an M W = 2.8 earthquake struck the metropolitan area between Leipzig and Halle, Germany, near the small town of Markranstädt. The earthquake was felt within 50 km from the epicenter and reached a local intensity of I 0 = IV. Already in 2015 and only 15 km northwest of the epicenter, a M W = 3.2 earthquake struck the area with a similar large felt radius and I 0 = IV. More than 1.1 million people live in the region, and the unusual occurrence of the two earthquakes led to public attention, because the tectonic activity is unclear and induced earthquakes have occurred in neighboring regions. Historical earthquakes south of Leipzig had estimated magnitudes up to M W ≈ 5 and coincide with NW-SE striking crustal basement faults. We use different seismological methods to analyze the two recent earthquakes and discuss them in the context of the known tectonic structures and historical seismicity. Novel stochastic full waveform simulation and inversion approaches are adapted for the application to weak, local earthquakes, to analyze mechanisms and ground motions and their relation to observed intensities. We find NW-SE striking normal faulting mechanisms for both earthquakes and centroid depths of 26 and 29 km. The earthquakes are located where faults with large vertical offsets of several hundred meters and Hercynian strike have developed since the Mesozoic. We use a stochastic full waveform simulation to explain the local peak ground velocities and calibrate the method to simulate intensities. Since the area is densely populated and has sensitive infrastructure, we simulate scenarios assuming that a 12-km long fault segment between the two recent earthquakes is ruptured and study the impact of rupture parameters on ground motions and expected damage.

  4. Correlation Wave-Front Sensing Algorithms for Shack-Hartmann-Based Adaptive Optics using a Point Source

    International Nuclear Information System (INIS)

    Poynee, L A

    2003-01-01

    Shack-Hartmann based Adaptive Optics system with a point-source reference normally use a wave-front sensing algorithm that estimates the centroid (center of mass) of the point-source image 'spot' to determine the wave-front slope. The centroiding algorithm suffers for several weaknesses. For a small number of pixels, the algorithm gain is dependent on spot size. The use of many pixels on the detector leads to significant propagation of read noise. Finally, background light or spot halo aberrations can skew results. In this paper an alternative algorithm that suffers from none of these problems is proposed: correlation of the spot with a ideal reference spot. The correlation method is derived and a theoretical analysis evaluates its performance in comparison with centroiding. Both simulation and data from real AO systems are used to illustrate the results. The correlation algorithm is more robust than centroiding, but requires more computation

  5. (Carbonyl-1κC)bis­[2,3(η5)-cyclo­penta­dien­yl][μ3-(S-methyl trithio­carbonato)methylidyne-1:2:3κ4 C,S′′:C:C](triphenyl­phosphine-1κP)(μ3-sulfido-1:2:3κ3 S)dicobalt(II)iron(II) trifluoro­methane­sulfonate

    Science.gov (United States)

    Manning, Anthony R.; McAdam, C. John; Palmer, Anthony J.; Simpson, Jim

    2008-01-01

    The asymmetric unit of the title compound, [FeCo2(C5H5)2(C3H3S3)S(C18H15P)(CO)]CF3SO3, consists of a triangular irondicobalt cluster cation and a trifluoro­methane­sulfonate anion. In the cation, the FeCo2 triangle is symmetrically capped on one face by an S atom and on the other by a C atom linked to a methyl trithio­carbonate residue that bridges the Fe—C bond. Each Co atom carries a cyclo­penta­dienyl ligand while the Fe atom coordinates to one carbonyl and one triphenyl­phosphine ligand. In the crystal structure, the cation is linked to the anion by a number of weak non-classical C—H⋯O and C—H⋯F hydrogen bonds and weak S⋯O (3.317 Å) and S⋯F (3.198 Å) inter­actions. The structure is further stabilized by additional inter­molecular C—H⋯O, C—H⋯F and O⋯O (2.942 Å) contacts, together with an unusual S⋯π(Cp) inter­action (S⋯centroid distance = 3.385 Å), generating an extended network. PMID:21202187

  6. Image thresholding in the high resolution target movement monitor

    Science.gov (United States)

    Moss, Randy H.; Watkins, Steve E.; Jones, Tristan H.; Apel, Derek B.; Bairineni, Deepti

    2009-03-01

    Image thresholding in the High Resolution Target Movement Monitor (HRTMM) is examined. The HRTMM was developed at the Missouri University of Science and Technology to detect and measure wall movements in underground mines to help reduce fatality and injury rates. The system detects the movement of a target with sub-millimeter accuracy based on the images of one or more laser dots projected on the target and viewed by a high-resolution camera. The relative position of the centroid of the laser dot (determined by software using thresholding concepts) in the images is the key factor in detecting the target movement. Prior versions of the HRTMM set the image threshold based on a manual, visual examination of the images. This work systematically examines the effect of varying threshold on the calculated centroid position and describes an algorithm for determining a threshold setting. First, the thresholding effects on the centroid position are determined for a stationary target. Plots of the centroid positions as a function of varying thresholds are obtained to identify clusters of thresholds for which the centroid position does not change for stationary targets. Second, the target is moved away from the camera in sub-millimeter increments and several images are obtained at each position and analyzed as a function of centroid position, target movement and varying threshold values. With this approach, the HRTMM can accommodate images in batch mode without the need for manual intervention. The capability for the HRTMM to provide automated, continuous monitoring of wall movement is enhanced.

  7. Propane-1,2-diammonium bis(pyridine-2,6-dicarboxylato-κ3O,N,O′nickelate(II tetrahydrate

    Directory of Open Access Journals (Sweden)

    Mohammad Ghadermazi

    2008-07-01

    Full Text Available The reaction of nickel(II nitrate hexahydrate, propane-1,2-diamine and pyridine-2,6-dicarboxylic acid in a 1:2:2 molar ratio in aqueous solution resulted in the formation of the title compound, (C3H12N2[Ni(C7H3NO42]·4H2O or (p-1,2-daH2[Ni(pydc2]·4H2O (where p-1,2-da is propane-1,2-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid. The geometry of the resulting NiN2O4 coordination can be described as distorted octahedral. Considerable C=O...π stacking interactions are observed between the carboxylate C=O groups and the pyridine rings of the (pydc2− fragments, with O...π distances of 3.1563 (12 and 3.2523 (12 Å and C=O...π angles of 95.14 (8 and 94.64 (8°. In the crystal structure, a wide range of non-covalent interactions, consisting of hydrogen bonding [O—H...O, N—H...O and C—H...O, with D...A distances ranging from 2.712 (2 to 3.484 (2 Å], ion pairing, π–π [centroid-to-centroid distance = 3.4825 (8 Å] and C=O...π stacking, connect the various components to form a supramolecular structure.

  8. Vibrational analysis of Fourier transform spectrum of the B u )–X g ...

    Indian Academy of Sciences (India)

    improved by putting the wave number of band origins in Deslandre table. The vibrational analysis was supported by determining the Franck–Condon factor and r-centroid values. Keywords. Fourier transform spectroscopy; electronic spectrum of selenium dimer; vibrational analysis; Franck–Condon factor; r-centroid values.

  9. 2-Isobutyl-6-(4-methoxyphenylimidazo[2,1-b][1,3,4]thiadiazole

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2011-02-01

    Full Text Available In the title compound, C15H17N3OS, the dihedral angle between the statistically planar imidazo[2,1-b][1,3,4]thiadiazole fused-ring system (r.m.s. deviation = 0.002 Å and the methyoxbenzene ring is 4.52 (6°. In the crystal, molecules are arranged into columns and stacked down the a axis. The crystal structure is stabilized by weak C—H...π and π–π interactions [centroid–centroid separations = 3.6053 (8 and 3.7088 (7 Å].

  10. [4,6-Dimethylpyrimidine-2(1H-thione-κS]iodidobis(triphenylphosphane-κPcopper(I

    Directory of Open Access Journals (Sweden)

    Chaveng Pakawatchai

    2012-06-01

    Full Text Available In the mononuclear title complex, [CuI(C6H8N2S(C18H15P2], the CuI ion is in a slightly distorted tetrahedral coordination geometry formed by two P atoms from two triphenylphosphane ligands, one S atom from a 4,6-dimethylpyrimidine-2(1H-thione ligand and one iodide ion. There is an intramolecular N—H...I hydrogen bond. In the crystal, π–π stacking interactions [centroid–centroid distance = 3.594 (1 Å] are observed.

  11. 1-[(2E-3-Phenylprop-2-en-1-yl]-1H-indole-2,3-dione

    Directory of Open Access Journals (Sweden)

    Fatima Zahrae Qachchachi

    2016-04-01

    Full Text Available In the title compound, C17H13NO2, the indole ring is essentially planar (r.m.s. deviation = 0.027 Å and is oriented at an angle of 69.33 (7° with respect to the phenyl ring. In the crystal, C—H...O hydrogen bonds link the molecules, forming zigzag chains propagating along the a-axis direction. Within the chains there are π–π stacking interactions [centroid–centroid distances = 3.7163 (8 and 3.7162 (8 Å] involving isatin groups of neighbouring molecules.

  12. tert-Butyl 2-(4-nitrophenoxyacetate

    Directory of Open Access Journals (Sweden)

    Qamar Ali

    2011-02-01

    Full Text Available In the title molecule, C12H15NO5, the nitrophenoxy portion is approximately planar (r.m.s. deviation = 0.034 Å and makes an angle of 84.8 (1° with respect to the –CH2–C(=O–O–C fragment. In the crystal, π–π stacking is observed between nearly parallel benzene rings of adjacent molecules, the centroid–centroid distance being 3.6806 (10 Å. Weak intermolecular C—H...O hydrogen bonding is present in the crystal structure.

  13. 8-Chloro-4-oxo-4H-chromene-3-carbaldehyde

    Directory of Open Access Journals (Sweden)

    Yoshinobu Ishikawa

    2014-07-01

    Full Text Available In the title compound, C10H5ClO3, a chlorinated 3-formylchromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.032 Å for the non-H atoms, with the largest deviation from the least-squares plane [0.0598 (14 Å] being for a pyran-ring C atom. In the crystal, molecules are linked through stacking interactions along the b axis [shortest centroid–centroid distance between the pyran and benzene rings = 3.566 (2 Å].

  14. 4-Aminobenzoic acid–1,2-bis(4-pyridylethane (2/1

    Directory of Open Access Journals (Sweden)

    Fwu Ming Shen

    2010-07-01

    Full Text Available In the title compound, C12H12N2·2C7H7NO2, the 4-aminobenzoic acid molecules are linked by O—H...N hydrogen bonds to 1,2-bis(4-pyridylethane, forming linear hydrogen bonded chains parallel to [2overline{1}1]. The structure exhibits a hydrogen-bonding network involving COOH...N(pyridyl and amine and carboxylic N—H... O interactions. In addition, π–π stacking interactions [centroid–centroid distance = 3.8622 (14 Å] are also present.

  15. (1-Phenyl-1H-1,2,3-triazol-4-ylmethyl pyridine-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Zakirjon Karimov

    2010-07-01

    Full Text Available In the title compound, C15H12N4O2, the dihedral angle between the planes of the nicotinoyloxy fragment and triazole ring is 88.61 (5°. The dihedral angle between the planes of triazole and benzene rings is 16.54 (11°. The crystal structure is stabilized by intermolecular C—H...N, C—H...O and C—H...π(triazole hydrogen bonds and aromatic π–π stacking interactions between the benzene and triazole rings [centroid–centroid distance = 3.895 (1 Å

  16. cis-Dichloridobis(2-isocyanophenyl 4-methoxybenzoatepalladium(II chloroform monosolvate

    Directory of Open Access Journals (Sweden)

    Alexander Tskhovrebov

    2012-12-01

    Full Text Available In the title compound, [PdCl2(C15H11NO32]·CHCl3, the PdII atom adopts a slightly distorted square-planar coordination geometry composed of two Cl atoms in cis positions and two C atoms from isocyanophenyl ligands. The molecular conformation is stabilized by π–π stacking interactions [shortest centroid–centroid distance = 3.600 (1 Å] between substituted benzene rings of different ligands. The crystal packing is characterized by C—H...O and C—H...Cl interactions involving the chloroform solvent molecules.

  17. 2-Hydroxy-1,6,7,8-tetramethoxy-3-methylanthraquinone

    Directory of Open Access Journals (Sweden)

    Shu-Juan Yu

    2008-02-01

    Full Text Available The title compound, C19H18O7, also known as chrysoobtusin, was isolated from Cassia tora L. (Leguminosae. The anthraquinone ring system is almost planar, the dihedral angle between the two benzene rings being 4.27 (4°. The structure is stabilized by intra- and intermolecular O—H...O and C—H...O hydrogen bonds, and by weak π–π stacking interactions along the b axis, with a centroid–centroid distance between related benzene rings of 3.800 (4 Å.

  18. N-(4-Chloro-1,3-benzothiazol-2-yl-2-(3-methylphenylacetamide monohydrate

    Directory of Open Access Journals (Sweden)

    H. S. Yathirajan

    2011-10-01

    Full Text Available In the title compound, C16H13ClN2OS·H2O, the dihedral angle between the mean planes of the benzothiazole ring system and the methylphenyl ring is 79.3 (6°. The crystal packing features intermolecular O—H...N, O—H...O and N—H...O hydrogen bonds involving the water molecule and weak C—H...O, C—H...Cg and π–π stacking interactions [centroid–centroid distances = 3.8743 (7, 3.7229 (7 and 3.7076 (8 Å].

  19. 2,2-Dimethyl-2,3-dihydropyrano[2,3-a]carbazol-4(11H-one

    Directory of Open Access Journals (Sweden)

    Makuteswaran Sridharan

    2008-11-01

    Full Text Available The title compound, C17H15NO2, was prepared from 1-hydroxycarbazole and 3,3-dimethylacrylic acid with a mixture of AlCl3 and POCl3 as the cyclization catalyst. Owing to the presence of the –CMe2– group, the molecule is not quite planar. In the crystal structre, strong N—H...O hydrogen bonds and weaker C—H...π interactions occur, and a slipped π–π stacking interaction [centroid–centroid separation = 3.8425 (8 Å] is also observed.

  20. 2,2′-Dimethyl-4,4′-bipyridine

    Directory of Open Access Journals (Sweden)

    Wilhelm Seichter

    2008-07-01

    Full Text Available In the crystal structure of the title compound, C12H12N2, the molecule is twisted around the central C—C bond, with a dihedral angle of 8.32 (5° between the mean planes of the pyridyl rings. The crystal structure is stabilized by arene stacking interactions, with a distance of 3.81 (1 Å between the ring centroids.

  1. 5-(Thiophen-2-ylmethyl-1,3,4-thiadiazol-2-amine

    Directory of Open Access Journals (Sweden)

    Jerry P. Jasinski

    2012-05-01

    Full Text Available In the title molecule, C7H7N3S2, the dihedral angle between the thiophene and thiadiazole rings is 72.99 (5°; the two rings are oriented so that the S atoms in each ring are on the same side. In the crystal, the three-dimensional network involves strong N—H...O hydrogen bonds, as well as C—H...π and π–π stacking interactions [centroid–centroid distances = 3.654 (1 and 3.495 (1 Å].

  2. (E-2-{[(4-Anilinophenylimino]methyl}-4-bromo-5-fluorophenol

    Directory of Open Access Journals (Sweden)

    Sedanur Kalecik

    2017-12-01

    Full Text Available In the title compound, C19H14BrFN2O, the dihedral angles between the central benzene ring and the pendant trisubstituted ring and phenyl group are 25.7 (2 and 51.7 (2°, respectively. The molecular conformation is influenced by an intramolecular O—H...N hydrogen bond. In the crystal, N—H...O hydrogen bonds link molecules into C(11 chains propagating in [100] and weak aromatic π–π stacking is also observed [centroid–centroid separation = 3.682 (3 Å

  3. Photometric Analysis in the Kepler Science Operations Center Pipeline

    Science.gov (United States)

    Twicken, Joseph D.; Clarke, Bruce D.; Bryson, Stephen T.; Tenenbaum, Peter; Wu, Hayley; Jenkins, Jon M.; Girouard, Forrest; Klaus, Todd C.

    2010-01-01

    We describe the Photometric Analysis (PA) software component and its context in the Kepler Science Operations Center (SOC) pipeline. The primary tasks of this module are to compute the photometric flux and photocenters (centroids) for over 160,000 long cadence (thirty minute) and 512 short cadence (one minute) stellar targets from the calibrated pixels in their respective apertures. We discuss the science algorithms for long and short cadence PA: cosmic ray cleaning; background estimation and removal; aperture photometry; and flux-weighted centroiding. We discuss the end-to-end propagation of uncertainties for the science algorithms. Finally, we present examples of photometric apertures, raw flux light curves, and centroid time series from Kepler flight data. PA light curves, centroid time series, and barycentric timestamp corrections are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and are made available to the general public in accordance with the NASA/Kepler data release policy.

  4. Core polarization and 3/2 states of some f-p shell nuclei

    International Nuclear Information System (INIS)

    Shelly, S.

    1976-01-01

    The energies, wavefunctions, spectroscopic factors and M1 transition strengths have been calculated for the 3/2 - states excited via single proton transfer to 2p3/2 orbit of the target nuclei 50 Ti, 52 Cr, 54 Fe and 56 Fe. The calculations have been done by using the Kuo and Brown interaction in the entire four shell space as well as the shrunk Kuo and Brown interaction calculated in (1f7/2-2p3/2) space. The salient feature of the calculation is that whereas the systematics of single particle strength distribution are well reproduced, the energy splitting between the calculated T> centroid and the centroid of T> states is always much smaller than that observed experimentally. It has been found, however, that the modified KB interaction widens the energy gap between the T> centroid and the centroid of T> states without appreciably affecting the final wave-functions. (author)

  5. Crystal structure of bis(4-acetylanilinium tetrachloridomercurate(II

    Directory of Open Access Journals (Sweden)

    Manickam Thairiyaraja

    2015-12-01

    Full Text Available The structure of the title salt, (C8H10NO2[HgCl4], is isotypic with that of the cuprate(II and cobaltate(II analogues. The asymmetric unit contains one 4-acetylanilinium cation and one half of a tetrachloridomercurate(II anion (point group symmetry m. The Hg—Cl distances are in the range 2.4308 (7–2.5244 (11 Å and the Cl—Hg—Cl angles in the range of 104.66 (2–122.94 (4°, indicating a considerable distortion of the tetrahedral anion. In the crystal, cations are linked by an intermolecular N—H...O hydrogen-bonding interaction, leading to a C(8 chain motif with the chains extending parallel to the b axis. There is also a π–π stacking interaction with a centroid-to-centroid distance of 3.735 (2 Å between neighbouring benzene rings along this direction. The anions lie between the chains and interact with the cations through intermolecular N—H...Cl hydrogen bonds, leading to the formation of a three-dimensional network structure.

  6. catena-Poly[bis(1,3-benzothiazol-3-ium [[dichloridoantimonate(III]-di-μ-chlorido-μ-oxido-[chloridoantimonate(III]-μ-chlorido

    Directory of Open Access Journals (Sweden)

    Oussama Chebout

    2016-02-01

    Full Text Available The title compound, {(C7H6NS2[Sb2Cl6O]}n, contains two benzothiazolidium cations and one tri-μ-chlorido-trichlorido-μ-oxido-diantimonate(III anion. The structure of the inorganic cation may be described as as being built up from two polyhedra, i.e. a square-pyramidal SbCl4O and a distorted octahedral SbOCl5 unit, sharing a common face (comprising the O atom and two Cl atoms. The two benzothiazole cations are quasi-planar and subtend a dihedral angle of 19.93 (5°. The crystal packing can be described by alternating (100 layers and [001] chains of the organic cations and inorganic anions connected through an extensive three-dimensional network of N—H...Cl, C—H...O and C—H...Cl hydrogen bonds. This is consolidated by slipped π–π stacking, with centroid-to-centroid distances between the benzothiazole rings of 3.7111 (18–3.8452 (16 Å. These interactions link the molecules within the layers and also link the layers together and reinforce the cohesion of the ionic structure.

  7. Crystal structure of μ-oxalodi-hydroxamato-bis-[(2,2'-bipyrid-yl)(di-methyl sulfoxide-κO)copper(II)] bis-(perchlorate).

    Science.gov (United States)

    Odarich, Irina A; Pavlishchuk, Anna V; Kalibabchuk, Valentina A; Haukka, Matti

    2016-02-01

    The centrosymmetric binuclear complex, [Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2, contains two copper(II) ions, connected through an N-deprotonated oxalodi-hydroxamic acid dianion, two terminal 2,2'-bi-pyridine ligands, and two apically coordinating dimethylsulfoxide mol-ecules. Two non-coordinating perchlorate anions assure electrical neutrality. The copper(II) ions in the complex dication [Cu2(C10H8N2)2(μ-C2H2N2O4)(C2H6SO)2](2+) are in an O2N3 square-pyramidal donor environment, the Cu-Cu separation being 5.2949 (4) Å. Two hydroxamate groups in the deprotonated oxalodi-hydroxamic acid are located trans to one each other. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the complex cations to the perchlorate anions. Further C-H⋯O hydrogen bonds combine with π-π contacts with a centroid-to-centroid separation of 3.6371 (12) Å to stack the mol-ecules along the a-axis direction.

  8. Crystal structure of μ-oxalodihydroxamato-bis[(2,2′-bipyridyl(dimethyl sulfoxide-κOcopper(II] bis(perchlorate

    Directory of Open Access Journals (Sweden)

    Irina A. Odarich

    2016-02-01

    Full Text Available The centrosymmetric binuclear complex, [Cu2(C2H2N2O4(C10H8N22(C2H6OS2](ClO42, contains two copper(II ions, connected through an N-deprotonated oxalodihydroxamic acid dianion, two terminal 2,2′-bipyridine ligands, and two apically coordinating dimethylsulfoxide molecules. Two non-coordinating perchlorate anions assure electrical neutrality. The copper(II ions in the complex dication [Cu2(C10H8N22(μ-C2H2N2O4(C2H6SO2]2+ are in an O2N3 square-pyramidal donor environment, the Cu–Cu separation being 5.2949 (4 Å. Two hydroxamate groups in the deprotonated oxalodihydroxamic acid are located trans to one each other. In the crystal, O—H...O and C—H...O hydrogen bonds link the complex cations to the perchlorate anions. Further C—H...O hydrogen bonds combine with π–π contacts with a centroid-to-centroid separation of 3.6371 (12 Å to stack the molecules along the a-axis direction.

  9. Crystal structure of bis(4-acetylanilinium tetrachloridocobaltate(II

    Directory of Open Access Journals (Sweden)

    Manickam Thairiyaraja

    2015-12-01

    Full Text Available The structure of the title salt, (C8H10NO2[CoCl4], is isotypic with the analogous cuprate(II structure. The asymmetric unit contains one 4-acetylanilinium cation and one half of a tetrachloridocobaltate(II anion for which the CoII atom and two Cl− ligands lie on a mirror plane. The Co—Cl distances in the distorted tetrahedral anion range from 2.2519 (6 to 2.2954 (9 Å and the Cl—Co—Cl angles range from 106.53 (2 to 110.81 (4°. In the crystal, cations are self-assembled by intermolecular N—H...O hydrogen-bonding interactions, leading to a C(8 chain motif with the chains running parallel to the b axis. π–π stacking interactions between benzene rings, with a centroid-to-centroid distance of 3.709 Å, are also observed along this direction. The CoCl42− anions are sandwiched between the cationic chains and interact with each other through intermolecular N—H...Cl hydrogen-bonding interactions, forming a three-dimensional network structure.

  10. Real-Time Forecasting of Echo-Centroid Motion.

    Science.gov (United States)

    1979-01-01

    is apparent that after five observations are obtained, the forecast error drops considerably. The normal lifetime of an echo (25 to 30 min) is...10kmI I ! Fig. 11. Track of 5 April 1978 mesocyclone (M) and two TVS’s (1) and (2). Times are CST. Pumpkin Center tornado is hatched and Marlow tornado is

  11. Circumcenter, Circumcircle and Centroid of a Triangle

    OpenAIRE

    Coghetto Roland

    2016-01-01

    We introduce, using the Mizar system [1], some basic concepts of Euclidean geometry: the half length and the midpoint of a segment, the perpendicular bisector of a segment, the medians (the cevians that join the vertices of a triangle to the midpoints of the opposite sides) of a triangle.

  12. Circumcenter, Circumcircle and Centroid of a Triangle

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2016-03-01

    Full Text Available We introduce, using the Mizar system [1], some basic concepts of Euclidean geometry: the half length and the midpoint of a segment, the perpendicular bisector of a segment, the medians (the cevians that join the vertices of a triangle to the midpoints of the opposite sides of a triangle.

  13. μ-Carbonato-bis-(bis-{2-[(diethyl-amino)-meth-yl]phen-yl}bis-muth(III)).

    Science.gov (United States)

    Soran, Albert P; Nema, Mihai G; Breunig, Hans J; Silvestru, Cristian

    2011-01-12

    The mol-ecular structure of the title compound, [Bi(2)(C(11)H(16)N)(4)(CO(3))], consists of a symmetrically bridging carbonato group which binds two [2-Et(2)NCH(2)C(6)H(4)](2)Bi units that are crystallographically related via a twofold rotation axis bis-ecting the carbonate group. The two Bi atoms and two of the C atoms directly bonded to bis-muth are quasi-planar [deviations of 0.323 (1) and 0.330 (9)Å for the Bi and C atoms, respectively] with the carbonate group. The remaining two ligands are in a trans arrangement relative to the quasi-planar (CBi)(2)CO(3) system. The metal atom is strongly coordinated by the N atom of one pendant arm [Bi-N = 2.739 (6) Å], almost trans to the O atom, while the N atom of the other pendant arm exhibits a weaker intra-molecular inter-action [Bi⋯N = 3.659 (7) Å] almost trans to a C atom. If both these intra-molecular N→Bi inter-actions per metal atom are considered, the overall coordination geometry at bis-muth becomes distorted square-pyramidal [(C,N)(2)BiO cores] and the compound can be described as a hypervalent 12-Bi-5 species. Additional quite short intra-molecular Bi⋯O inter-actions are also present [3.796 (8)-4.020 (9) Å]. Inter-molecular associations through weak η(6)⋯Bi inter-actions [Bi⋯centroid of benzene ring = 3.659 (1) Å] lead to a ribbon-like supra-molecular association.

  14. Positron annihilation studies in the field induced depletion regions of metal-oxide-semiconductor structures

    Science.gov (United States)

    Asoka-Kumar, P.; Leung, T. C.; Lynn, K. G.; Nielsen, B.; Forcier, M. P.; Weinberg, Z. A.; Rubloff, G. W.

    1992-06-01

    The centroid shifts of positron annihilation spectra are reported from the depletion regions of metal-oxide-semiconductor (MOS) capacitors at room temperature and at 35 K. The centroid shift measurement can be explained using the variation of the electric field strength and depletion layer thickness as a function of the applied gate bias. An estimate for the relevant MOS quantities is obtained by fitting the centroid shift versus beam energy data with a steady-state diffusion-annihilation equation and a derivative-gaussian positron implantation profile. Inadequacy of the present analysis scheme is evident from the derived quantities and alternate methods are required for better predictions.

  15. Positron annihilation studies in the field induced depletion regions of metal-oxide-semiconductor structures

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Leung, T.C.; Lynn, K.G.; Nielsen, B.; Forcier, M.P.; Weinberg, Z.A.; Rubloff, G.W.

    1992-01-01

    The centroid shifts of positron annihilation spectra are reported from the depletion regions of metal-oxide-semiconductor (MOS) capacitors at room temperature and at 35 K. The centroid shift measurement can be explained using the variation of the electric field strength and depletion layer thickness as a function of the applied gate bias. An estimate for the relevant MOS quantities is obtained by fitting the centroid shift versus beam energy data with a steady-state diffusion-annihilation equation and a derivative-gaussian positron implantation profile. Inadequacy of the present analysis scheme is evident from the derived quantities and alternate methods are required for better predictions

  16. Method of transient identification based on a possibilistic approach, optimized by genetic algorithm

    International Nuclear Information System (INIS)

    Almeida, Jose Carlos Soares de

    2001-02-01

    This work develops a method for transient identification based on a possible approach, optimized by Genetic Algorithm to optimize the number of the centroids of the classes that represent the transients. The basic idea of the proposed method is to optimize the partition of the search space, generating subsets in the classes within a partition, defined as subclasses, whose centroids are able to distinguish the classes with the maximum correct classifications. The interpretation of the subclasses as fuzzy sets and the possible approach provided a heuristic to establish influence zones of the centroids, allowing to achieve the 'don't know' answer for unknown transients, that is, outside the training set. (author)

  17. Variability of femoral muscle attachments.

    Science.gov (United States)

    Duda, G N; Brand, D; Freitag, S; Lierse, W; Schneider, E

    1996-09-01

    Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

  18. Accuracy of Shack-Hartmann wavefront sensor using a coherent wound fibre image bundle

    Science.gov (United States)

    Zheng, Jessica R.; Goodwin, Michael; Lawrence, Jon

    2018-03-01

    Shack-Hartmannwavefront sensors using wound fibre image bundles are desired for multi-object adaptive optical systems to provide large multiplex positioned by Starbugs. The use of a large-sized wound fibre image bundle provides the flexibility to use more sub-apertures wavefront sensor for ELTs. These compact wavefront sensors take advantage of large focal surfaces such as the Giant Magellan Telescope. The focus of this paper is to study the wound fibre image bundle structure defects effect on the centroid measurement accuracy of a Shack-Hartmann wavefront sensor. We use the first moment centroid method to estimate the centroid of a focused Gaussian beam sampled by a simulated bundle. Spot estimation accuracy with wound fibre image bundle and its structure impact on wavefront measurement accuracy statistics are addressed. Our results show that when the measurement signal-to-noise ratio is high, the centroid measurement accuracy is dominated by the wound fibre image bundle structure, e.g. tile angle and gap spacing. For the measurement with low signal-to-noise ratio, its accuracy is influenced by the read noise of the detector instead of the wound fibre image bundle structure defects. We demonstrate this both with simulation and experimentally. We provide a statistical model of the centroid and wavefront error of a wound fibre image bundle found through experiment.

  19. Long Josephson Junction Stack Coupled to a Cavity

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Pedersen, Niels Falsig; Groenbech-Jensen, N.

    2007-01-01

    A stack of inductively coupled long Josephson junctions are modeled as a system of coupled sine-Gordon equations. One boundary of the stack is coupled electrically to a resonant cavity. With one fluxon in each Josephson junction, the inter-junction fluxon forces are repulsive. We look at a possible...... transition, induced by the cavity, to a bunched state....

  20. GPS survey in long baseline neutrino-oscillation measurement

    CERN Document Server

    Noumi, H; Inagaki, T; Hasegawa, T; Katoh, Y; Kohama, M; Kurodai, M; Kusano, E; Maruyama, T; Minakawa, M; Nakamura, K; Nishikawa, K; Sakuda, M; Suzuki, Y; Takasaki, M; Tanaka, K H; Yamanoi, Y; 10.1109/TNS.2004.836042

    2004-01-01

    We made a series of surveys to obtain neutrino beam line direction toward SuperKamiokande (SK) at a distance of 250 km for the long- baseline neutrino oscillation experiment at KEK. We found that the beam line is directed to SK within 0.03 mr and 0.09 mr (in sigma) in the horizontal and vertical directions, respectively. During beam operation, we monitored the muon distribution from secondary pions produced at the target and collected by a magnetic horn system. We found that the horn system functions like a lens of a point-to- parallel optics with magnification of approximately -100 and the focal length of 2.3 m. Namely, a small displacement of the primary beam position at the target is magnified about a factor -100 at the muon centroid, while the centroid position is almost stable against a change of the incident angle of the primary beam. Therefore, the muon centroid can be a useful monitor of the neutrino beam direction. We could determine the muon centroid within 6 mm and 12 mm in horizontal and vertical ...

  1. Computing travel time when the exact address is unknown: a comparison of point and polygon ZIP code approximation methods.

    Science.gov (United States)

    Berke, Ethan M; Shi, Xun

    2009-04-29

    Travel time is an important metric of geographic access to health care. We compared strategies of estimating travel times when only subject ZIP code data were available. Using simulated data from New Hampshire and Arizona, we estimated travel times to nearest cancer centers by using: 1) geometric centroid of ZIP code polygons as origins, 2) population centroids as origin, 3) service area rings around each cancer center, assigning subjects to rings by assuming they are evenly distributed within their ZIP code, 4) service area rings around each center, assuming the subjects follow the population distribution within the ZIP code. We used travel times based on street addresses as true values to validate estimates. Population-based methods have smaller errors than geometry-based methods. Within categories (geometry or population), centroid and service area methods have similar errors. Errors are smaller in urban areas than in rural areas. Population-based methods are superior to the geometry-based methods, with the population centroid method appearing to be the best choice for estimating travel time. Estimates in rural areas are less reliable.

  2. Two-dimensional shape recognition using oriented-polar representation

    Science.gov (United States)

    Hu, Neng-Chung; Yu, Kuo-Kan; Hsu, Yung-Li

    1997-10-01

    To deal with such a problem as object recognition of position, scale, and rotation invariance (PSRI), we utilize some PSRI properties of images obtained from objects, for example, the centroid of the image. The corresponding position of the centroid to the boundary of the image is invariant in spite of rotation, scale, and translation of the image. To obtain the information of the image, we use the technique similar to Radon transform, called the oriented-polar representation of a 2D image. In this representation, two specific points, the centroid and the weighted mean point, are selected to form an initial ray, then the image is sampled with N angularly equispaced rays departing from the initial rays. Each ray contains a number of intersections and the distance information obtained from the centroid to the intersections. The shape recognition algorithm is based on the least total error of these two items of information. Together with a simple noise removal and a typical backpropagation neural network, this algorithm is simple, but the PSRI is achieved with a high recognition rate.

  3. Linking Action Learning and Inter-Organisational Learning: The Learning Journey Approach

    Science.gov (United States)

    Schumacher, Thomas

    2015-01-01

    The article presents and illustrates the learning journey (LJ)--a new management development approach to inter-organisational learning based on observation, reflection and problem-solving. The LJ involves managers from different organisations and applies key concepts of action learning and systemic organisational development. Made up of…

  4. Crystal structure of a new monoclinic polymorph of N-(4-methyl-phen-yl)-3-nitro-pyridin-2-amine.

    Science.gov (United States)

    Aznan, Aina Mardia Akhmad; Abdullah, Zanariah; Lee, Vannajan Sanghiran; Tiekink, Edward R T

    2014-08-01

    The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, with Z' = 4) of the previously reported monoclinic (P21/c, with Z' = 2) form [Akhmad Aznan et al. (2010 ▶). Acta Cryst. E66, o2400]. Four independent mol-ecules comprise the asymmetric unit, which have the common features of a syn disposition of the pyridine N atom and the toluene ring, and an intra-molecular amine-nitro N-H⋯O hydrogen bond. The differences between mol-ecules relate to the dihedral angles between the rings which range from 2.92 (19) to 26.24 (19)°. The geometry-optimized structure [B3LYP level of theory and 6-311 g+(d,p) basis set] has the same features except that the entire mol-ecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C-H⋯O, C-H⋯π, nitro-N-O⋯π and π-π inter-actions [inter-centroid distances = 3.649 (2)-3.916 (2) Å].

  5. Crystal structure of bis-[(phenyl-methanamine-κN)(phthalocyaninato-κ(4) N)zinc] phenyl-methan-amine tris-olvate.

    Science.gov (United States)

    Shamsudin, Norzianah; Tan, Ai Ling; Wimmer, Franz L; Young, David J; Tiekink, Edward R T

    2015-09-01

    The asymmetric unit of the title compound, 2[Zn(C32H16N8)(C7H9N)]·3C7H9N, comprises two independent complex mol-ecules and three benzyl-amine solvent mol-ecules. Each complex mol-ecule features a penta-coordinated Zn(2+) ion within a square-pyramidal geometry, whereby the N5 donor set is defined by four atoms of the phthalocyaninate dianion (PC) and an N-bound benzyl-amine mol-ecule; it is the relative orientations of the latter that differentiate between the independent complex mol-ecules. The uncoordinated benzyl-amine mol-ecules display different conformations in the structure, with syn-Car-Car-Cm-N (ar = aromatic, m = methyl-ene) torsion angles spanning the range -28.7 (10) to 35.1 (14)°. In the crystal, N-H⋯N and N-H⋯π inter-actions lead to supra-molecular layers in the ab plane. The layers have a zigzag topology, have the coordinating and non-coordinating benzyl-amine mol-ecules directed to the inside, and present the essentially flat PC resides to the outside. This arrangement enables adjacent layers to associate via π-π inter-actions [inter-centroid distance between pyrrolyl and fused-benzene rings = 3.593 (2) Å] so that a three-dimensional architecture is formed.

  6. 360-degrees profilometry using strip-light projection coupled to Fourier phase-demodulation.

    Science.gov (United States)

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo

    2016-01-11

    360 degrees (360°) digitalization of three dimensional (3D) solids using a projected light-strip is a well-established technique in academic and commercial profilometers. These profilometers project a light-strip over the digitizing solid while the solid is rotated a full revolution or 360-degrees. Then, a computer program typically extracts the centroid of this light-strip, and by triangulation one obtains the shape of the solid. Here instead of using intensity-based light-strip centroid estimation, we propose to use Fourier phase-demodulation for 360° solid digitalization. The advantage of Fourier demodulation over strip-centroid estimation is that the accuracy of phase-demodulation linearly-increases with the fringe density, while in strip-light the centroid-estimation errors are independent. Here we proposed first to construct a carrier-frequency fringe-pattern by closely adding the individual light-strip images recorded while the solid is being rotated. Next, this high-density fringe-pattern is phase-demodulated using the standard Fourier technique. To test the feasibility of this Fourier demodulation approach, we have digitized two solids with increasing topographic complexity: a Rubik's cube and a plastic model of a human-skull. According to our results, phase demodulation based on the Fourier technique is less noisy than triangulation based on centroid light-strip estimation. Moreover, Fourier demodulation also provides the amplitude of the analytic signal which is a valuable information for the visualization of surface details.

  7. Correlated lateral phase separations in stacks of lipid membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Takuma, E-mail: hoshino-takuma@ed.tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Komura, Shigeyuki, E-mail: komura@tmu.ac.jp [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Andelman, David, E-mail: andelman@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 (Israel); Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China)

    2015-12-28

    Motivated by the experimental study of Tayebi et al. [Nat. Mater. 11, 1074 (2012)] on phase separation of stacked multi-component lipid bilayers, we propose a model composed of stacked two-dimensional Ising spins. We study both its static and dynamical features using Monte Carlo simulations with Kawasaki spin exchange dynamics that conserves the order parameter. We show that at thermodynamical equilibrium, due to strong inter-layer correlations, the system forms a continuous columnar structure for any finite interaction across adjacent layers. Furthermore, the phase separation shows a faster dynamics as the inter-layer interaction is increased. This temporal behavior is mainly due to an effective deeper temperature quench because of the larger value of the critical temperature, T{sub c}, for larger inter-layer interaction. When the temperature ratio, T/T{sub c}, is kept fixed, the temporal growth exponent does not increase and even slightly decreases as a function of the increased inter-layer interaction.

  8. 3,5-Bis(4-methoxyphenyl-1-phenyl-4,5-dihydro-1H-pyrazole

    Directory of Open Access Journals (Sweden)

    Zeliha Baktır

    2011-02-01

    Full Text Available In the title compound, C23H22N2O2, the central pyrazole ring is nearly planar (r.m.s. deviation = 0.046 Å and it makes a dihedral angle of 18.5 (2° with the phenyl ring. The dihedral angles between the phenyl and the two methoxy-substituted phenyl rings are 26.2 (2 and 80.6 (2°. The crystal structure is stabilized by C—H...π stacking interactions and weak π–π interactions [centriod–centroid distance = 3.891 (2 Å].

  9. meso-4,5-Diphenylimidazolidin-2-one

    Directory of Open Access Journals (Sweden)

    Alan J. Lough

    2009-12-01

    Full Text Available The crystal structure determination of the title compound, C15H14N2O, confirms the cis relationship between the phenyl groups at the 4- and 5-positions on the imidazolidine ring. The dihedral angle between the two phenyl rings is 48.14 (6°. In the crystal structure, intermolecular N—H...O hydrogen bonds link molecules into centrosymmetric dimers. These dimers are, in turn, linked into a two-dimensional network via weak N—H...π(arene interactions and π–π stacking interactions with centroid–centroid distances of 3.6937 (11 Å.

  10. N,N′-Bis(4-bromobenzylidenebutane-1,4-diamine

    Directory of Open Access Journals (Sweden)

    Reza Kia

    2008-10-01

    Full Text Available The molecule of the title Schiff base compound, C18H18Br2N2, lies across a crystallographic inversion centre and adopts an E configuration with respect to the C=N bond. In the crystal structure, molecules are linked into chains along [201] through intermolecular Br...Br interactions [3.3747 (3 Å], which are significantly shorter than the sum of the van der Waals radii for Br atoms (3.70 Å. The crystal structure is further stabilized by π–π stacking interactions [centroid–centroid distance 3.6811 (11 Å].

  11. Butane-1,2,3,4-tetracarboxylic acid–1,10-phenanthroline–water (1/2/2

    Directory of Open Access Journals (Sweden)

    Hong-lin Zhu

    2011-07-01

    Full Text Available The asymmetric unit of the title compound, 2C12H8N2·C8H10O8·2H2O, contains one 1,10-phenanthroline molecule, one half-molecule of butane-1,2,3,4-tetracarboxylic acid (H4BTC and a water molecule, with the complete tetra-acid generated by crystallographic inversion symmetry. Intermolecular O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.672 (2 and 3.708 (2 Å form an extensive three-dimensional network, which consolidates the crystal packing.

  12. 6,7-Dichloro-3-(2,4-dichlorobenzylquinoxalin-2(1H-one

    Directory of Open Access Journals (Sweden)

    Jinpeng Zhang

    2012-08-01

    Full Text Available In the title compound, C15H8Cl4N2O, the quinoxaline ring system is almost planar, with a dihedral angle between the benzene and pyrazine rings of 3.1 (2°. The 2,4-dichlorophenyl ring is approximately perpendicular to the pyrazine ring, with a dihedral angle of 86.47 (13° between them. The crystal packing features intermolecular N—H...O hydrogen bonds and π–π stacking interactions, with centroid–centroid distances in the range 3.699 (3–4.054 (3 Å.

  13. trans-(1,8-Dibenzyl-1,3,6,8,10,13-hexaazacyclotetradecanediisonicotinatonickel(II

    Directory of Open Access Journals (Sweden)

    Kil Sik Min

    2008-02-01

    Full Text Available In the centrosymmetric title compound, [Ni(C6H4NO22(C22H34N6], the NiII ion is bonded to the four secondary N atoms of the macrocyclic ligand in a square-planar fashion and two carboxylate O atoms of the isonicotinate ions in axial positions, resulting in a tetragonally distorted octahedron. An offset face-to-face π–π stacking interaction [centroid–centroid distance = 3.674(4 Å] and N—H...N and N—H...O hydrogen-bonding interactions give rise to a one-dimensional supramolecular structure in the solid state.

  14. Dicarbonyl[2-hydroxy-3,5,7-tris(morpholinomethylcyclohepta-2,4,6-trienonato(1–-κ2O1,O2]rhodium(I

    Directory of Open Access Journals (Sweden)

    G. Steyl

    2008-12-01

    Full Text Available In the title compound, [Rh(C22H32N3O5(CO2], the RhI atom is coordinated by two carbonyl ligands and two tropolonate O atoms in a distorted square-planar geometry. It is an example of a new type of tropolone derivative that has not been characterized via solid-state methods. Weak intramolecular C—H...N and intermolecular C—H...O hydrogen bonds, and π–π stacking interactions between the tropolone rings [centroid–centroid distance = 3.590 (8 Å] are observed in the crystal structure.

  15. [2,6-Difluoro-3-(pyridin-2-yl-κNpyridin-4-yl-κC4](pentane-2,4-dionato-κ2O,O′iridium(III

    Directory of Open Access Journals (Sweden)

    Kaijun Luo

    2013-11-01

    Full Text Available The title compound, [Ir(C10H5F2N22(C5H7O2], has a distorted octahedral coordination geometry around the IrIII atom, retaining the cis-C,C/trans-N,N chelate disposition in two 2,6-difluoro-3-(pyridin-2-yl-κNpyridin-4-yl ligands which are nearly mutually perpendicular [dihedral angle = 82.75 (15°]. The molecular structure is stabilized by weak C—H...O and C—H...F hydrogen-bond interactions. The crystal structure is stabilized by π–π stacking interactions (centroid–centroid distance = 3.951 Å.

  16. Diaquabis[2-(2-hydroxyethylpyridine-κ2N,O]cobalt(II dichloride

    Directory of Open Access Journals (Sweden)

    Hocine Merazig

    2013-08-01

    Full Text Available In the title salt, [Co(C7H9NO2(H2O2]Cl2, the CoII cation, located on an inversion center, is N,O-chelated by two hydroxyethylpyridine ligands and coordinated by two water molecules in a distorted O4N2 octahedral geometry. In the crystal, the Cl− anions link with the complex cations via O—H...Cl hydrogen bonds, forming a three-dimensional supramolecular architecture. π–π stacking is observed between the pyridine rings of adjacent molecules [centroid–centroid distance = 3.5810 (11 Å].

  17. 2-Amino-5-fluorobenzoic acid

    Directory of Open Access Journals (Sweden)

    K. Gunasekaran

    2013-03-01

    Full Text Available In the title compound, C7H6FNO2, the molecule is almost planar (r.m.s. deviation for the non-H atoms = 0.015 Å and an intramolecular N—H...O hydrogen bond closes an S(6 ring. In the crystal, inversion dimers linked by pairs of O—H...O hydrogen bonds generate R22(8 loops. Weak N—H...F hydrogen bonds, short F...F contacts [2.763 (2 Å] and aromatic π–π stacking interactions [centroid–centroid separation = 3.5570 (11 Å] are also observed in the crystal structure.

  18. 3-Ethyl-5-(4-methoxyphenoxy-2-(pyridin-4-yl-3H-imidazo[4,5-b]pyridine

    Directory of Open Access Journals (Sweden)

    S. Ranjith

    2011-07-01

    Full Text Available In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5°]. The pyridine ring makes a dihedral angle of 35.5 (5° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking interaction between the phenyl rings of neighbouring molecules [centroid–centroid distance = 3.772 (2 Å, interplanar distance = 3.546 (2 Å and slippage = 1.286 (2 Å].

  19. Crystal structure and Hirshfeld surface analysis of (E-3-(2-chloro-6-fluorophenyl-1-(3-fluoro-4-methoxyphenylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Nur Hafiq Hanif Hassan

    2016-05-01

    Full Text Available In the title chalcone derivative, C16H11ClF2O2, the enone group adopts an E conformation. The dihedral angle between the benzene rings is 0.47 (9° and an intramolecular C—H...F hydrogen bond closes an S(6 ring. In the crystal, molecules are linked into a three-dimensional network by C—H...O hydrogen bonds and aromatic π–π stacking interactions are also observed [centroid–centroid separation = 3.5629 (18 Å]. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis.

  20. Crystal structure of 2-bromo-1,4-dihydroxy-9,10-anthraquinone

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    Wataru Furukawa

    2014-10-01

    Full Text Available In an attempt to brominate 1,4-dipropoxy-9,10-anthraquinone, a mixture of products, including the title compound, C14H7BrO4, was obtained. The molecule is essentially planar (r.m.s. deviation = 0.029 Å and two intramolecular O—H...O hydrogen bonds occur. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds, Br...O contacts [3.240 (5 Å], and π–π stacking interactions [shortest centroid–centroid separation = 3.562 (4 Å], generating a three-dimensional network.

  1. Stacking stability of MoS2 bilayer: An ab initio study

    International Nuclear Information System (INIS)

    Tao Peng; Guo Huai-Hong; Yang Teng; Zhang Zhi-Dong

    2014-01-01

    The study of the stacking stability of bilayer MoS 2 is essential since a bilayer has exhibited advantages over single layer MoS 2 in many aspects for nanoelectronic applications. We explored the relative stability, optimal sliding path between different stacking orders of bilayer MoS 2 , and (especially) the effect of inter-layer stress, by combining first-principles density functional total energy calculations and the climbing-image nudge-elastic-band (CI-NEB) method. Among five typical stacking orders, which can be categorized into two kinds (I: AA, AB and II: AA', AB', A'B), we found that stacking orders with Mo and S superposing from both layers, such as AA' and AB, is more stable than the others. With smaller computational efforts than potential energy profile searching, we can study the effect of inter-layer stress on the stacking stability. Under isobaric condition, the sliding barrier increases by a few eV/(ucGPa) from AA' to AB', compared to 0.1 eV/(ucGPa) from AB to [AB]. Moreover, we found that interlayer compressive stress can help enhance the transport properties of AA'. This study can help understand why inter-layer stress by dielectric gating materials can be an effective means to improving MoS 2 on nanoelectronic applications. (condensed matter: structural, mechanical, and thermal properties)

  2. μ-Carbonato-bis­(bis­{2-[(diethyl­amino)­meth­yl]phen­yl}bis­muth(III))

    Science.gov (United States)

    Soran, Albert P.; Nema, Mihai G.; Breunig, Hans J.; Silvestru, Cristian

    2011-01-01

    The mol­ecular structure of the title compound, [Bi2(C11H16N)4(CO3)], consists of a symmetrically bridging carbonato group which binds two [2-Et2NCH2C6H4]2Bi units that are crystallographically related via a twofold rotation axis bis­ecting the carbonate group. The two Bi atoms and two of the C atoms directly bonded to bis­muth are quasi-planar [deviations of 0.323 (1) and 0.330 (9)Å for the Bi and C atoms, respectively] with the carbonate group. The remaining two ligands are in a trans arrangement relative to the quasi-planar (CBi)2CO3 system. The metal atom is strongly coordinated by the N atom of one pendant arm [Bi—N = 2.739 (6) Å], almost trans to the O atom, while the N atom of the other pendant arm exhibits a weaker intra­molecular inter­action [Bi⋯N = 3.659 (7) Å] almost trans to a C atom. If both these intra­molecular N→Bi inter­actions per metal atom are considered, the overall coordination geometry at bis­muth becomes distorted square-pyramidal [(C,N)2BiO cores] and the compound can be described as a hypervalent 12-Bi-5 species. Additional quite short intra­molecular Bi⋯O inter­actions are also present [3.796 (8)–4.020 (9) Å]. Inter­molecular associations through weak η6⋯Bi inter­actions [Bi⋯centroid of benzene ring = 3.659 (1) Å] lead to a ribbon-like supra­molecular association. PMID:21522836

  3. Crystal structure of 2-oxo-2H-chromen-7-yl 4-fluorobenzoate

    Directory of Open Access Journals (Sweden)

    Akoun Abou

    2018-05-01

    Full Text Available In the title compound, C16H9FO4, (I, the benzene ring is oriented at an acute angle of 59.03 (15° relative to the coumarin plane (r.m.s deviation = 0.009 Å. This conformation of (I is stabilized by an intramolecular C—H...O hydrogen bond, which closes a five-membering ring. In the crystal, molecules of (I form infinite zigzag chains along the b-axis direction, linked by C—H...O hydrogen bonds. Furthermore, the crystal structure is supported by π–π stacking interactions between neighbouring pyrone and benzene or coumarin rings [centroid–centroid distances in the range 3.5758 (18–3.6115 (16 Å], as well as C=O...π interactions [O...centroid distances in the range 3.266 (3–3.567 (3 Å]. The theoretical data for (I obtained from quantum chemical calculations are in good agreement with the observed structure, although the calculated C—O—C—C torsion angle between the coumarin fragment and the benzene ring (73.7° is somewhat larger than the experimental value [63.4 (4°]. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.

  4. (E)-Methyl 3-(3,4-dimeth-oxy-phen-yl)-2-[(1,3-dioxoisoindolin-2-yl)meth-yl]acrylate.

    Science.gov (United States)

    Kannan, D; Bakthadoss, M; Lakshmanan, D; Murugavel, S

    2012-04-01

    In the title compound, C(21)H(19)NO(6), the isoindole ring system is essentially planar [maximum deviation = 0.019 (2) Å for the N atom] and is oriented at a dihedral angle of 51.3 (1)° with respect to the benzene ring. The two meth-oxy groups are almost coplanar with the attached benzene ring [C-O-C-C = 3.7 (4) and 4.3 (4)°]. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, mol-ecules are linked through bifurcated C-H⋯(O,O) hydrogen bonds having R(1) (2)(5) ring motifs, forming chains along the b-axis direction. The crystal packing is further stabilzed by π-π inter-actions [centriod-centroid distance = 3.463 (1) Å].

  5. Using network metrics to investigate football team players' connections: A pilot study

    Directory of Open Access Journals (Sweden)

    Filipe Manuel Clemente

    2014-09-01

    Full Text Available The aim of this pilot study was propose a set of network methods to measure the specific properties of football teams. These metrics were organized on "meso" and "micro" analysis levels. Five official matches of the same team on the First Portuguese Football League were analyzed. An overall of 577 offensive plays were analyzed from the five matches. From the adjacency matrices developed per each offensive play it were computed the scaled connectivity, the clustering coefficient and the centroid significance and centroid conformity. Results showed that the highest values of scaled connectivity were found in lateral defenders and central and midfielder players and the lowest values were found in the striker and goalkeeper. The highest values of clustering coefficient were generally found in midfielders and forwards. In addition, the centroid results showed that lateral and central defenders tend to be the centroid players in the attacking process. In sum, this study showed that network metrics can be a powerful tool to help coaches to understanding the specific team's properties, thus supporting decision-making and improving sports training based on match analysis.

  6. Automatic detection and quantitative analysis of cells in the mouse primary motor cortex

    Science.gov (United States)

    Meng, Yunlong; He, Yong; Wu, Jingpeng; Chen, Shangbin; Li, Anan; Gong, Hui

    2014-09-01

    Neuronal cells play very important role on metabolism regulation and mechanism control, so cell number is a fundamental determinant of brain function. Combined suitable cell-labeling approaches with recently proposed three-dimensional optical imaging techniques, whole mouse brain coronal sections can be acquired with 1-μm voxel resolution. We have developed a completely automatic pipeline to perform cell centroids detection, and provided three-dimensional quantitative information of cells in the primary motor cortex of C57BL/6 mouse. It involves four principal steps: i) preprocessing; ii) image binarization; iii) cell centroids extraction and contour segmentation; iv) laminar density estimation. Investigations on the presented method reveal promising detection accuracy in terms of recall and precision, with average recall rate 92.1% and average precision rate 86.2%. We also analyze laminar density distribution of cells from pial surface to corpus callosum from the output vectorizations of detected cell centroids in mouse primary motor cortex, and find significant cellular density distribution variations in different layers. This automatic cell centroids detection approach will be beneficial for fast cell-counting and accurate density estimation, as time-consuming and error-prone manual identification is avoided.

  7. (2E)-1-(2,6-Dichloro-3-fluoro-phen-yl)-3-phenyl-prop-2-en-1-one.

    Science.gov (United States)

    Praveen, Aletti S; Yathirajan, Hemmige S; Narayana, Badiadka; Gerber, Thomas; Hosten, Eric; Betz, Richard

    2012-04-01

    In the title compound, C(15)H(9)Cl(2)FO, the F atom shows positional disorder over two positions, with site-occupancy factors of 0.747 (4) and 0.253 (4). The dihedral angle between the rings is 86.37 (10)°. In the crystal, C-H⋯O contacts connect the mol-ecules into chains along the c axis. The shortest inter-centroid distance between two aromatic systems is 3.6686 (12) Å and is apparent between the halogenated rings.

  8. Ellipsoid analysis of calvarial shape.

    Science.gov (United States)

    Jacobsen, Petra A; Becker, Devra; Govier, Daniel P; Krantz, Steven G; Kane, Alex

    2009-09-01

    The purpose of this research was to develop a novel quantitative method of describing calvarial shape by using ellipsoid geometry. The pilot application of Ellipsoid Analysis was to compare calvarial form among individuals with untreated unilateral coronal synostosis, metopic synostosis, and sagittal synostosis and normal subjects. The frontal, parietal, and occipital bones of 10 preoperative patients for each of the four study groups were bilaterally segmented into six regions using three-dimensional skull reconstructions generated by ANALYZE imaging software from high-resolution computed tomography scans. Points along each segment were extracted and manipulated using a MATLAB-based program. The points were fit to the least-squares nearest ellipsoid. Relationships between the six resultant right and left frontal, parietal, and occipital ellipsoidal centroids (FR, FL, PR, PL, OR, and OL, respectively) were tested for association with a synostotic group. Results from the pilot study showed meaningful differences between length ratio, angular, and centroid distance relationships among synostotic groups. The most substantial difference was exhibited in the centroid distance PL-PR between patients with sagittal synostosis and metopic synostosis. The measures most commonly significant were centroid distances FL-PR and FL-PL and the angle OR-FR-PR. Derived centroid relationships were reproducible. Ellipsoid Analysis may offer a more refined approach to quantitative analysis of cranial shape. Symmetric and asymmetric forms can be compared directly. Relevant shape information between traditional landmarks is characterized. These techniques may have wider applicability in quantifying craniofacial morphology with increase in both specificity and general applicability over current methods.

  9. Automated Slicing for a Multi-Axis Metal Deposition System (Preprint)

    Science.gov (United States)

    2006-09-01

    experimented with different materials like H13 tool steel to build the part. Following the same slicing and scanning toolpath result, there is a geometric...and analysis tool -centroidal axis. Similar to medial axis, it contains geometry and topological information but is significantly computationally...geometry reasoning and analysis tool -centroidal axis. Similar to medial axis, it contains geometry and topological information but is significantly

  10. A comparison of methods for calculating population exposure estimates of daily weather for health research

    Directory of Open Access Journals (Sweden)

    Dear Keith BG

    2006-09-01

    Full Text Available Abstract Background To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. Results Options based on values derived from sites internal to postal areas, or from nearest neighbour sites – that is, using proximity polygons around weather stations intersected with postal areas – tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. Conclusion To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons, is too limited. The most

  11. Centroid-Based Document Classification Algorithms: Analysis & Experimental Results

    Science.gov (United States)

    2000-03-06

    0.24 traffick 0.23 gang 0.23 polic 0.20 heroin 0.17 arrest 0.16 narcot 0.16 kg 0.15 addict 0.12 cocain 11 0.49 nafta 0.40 mexico 0.24 job 0.23...mafia 0.12 crime 19 0.36 speci 0.25 whale 0.23 endang 0.23 wolve 0.22 wildlif 0.17 hyph 0.17 blank 0.16 mammal 0.15 marin 0.15 wolf 20 0.30 rwanda 0.25...oil 34 0.64 drug 0.20 legal 0.16 greif 0.15 court 0.14 colombia 0.14 addict 0.13 de 0.11 traffick 0.11 bogota 0.11 decrimin 35 0.24 boate 0.23 ship

  12. Determination of star bodies from p-centroid bodies

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Proceedings – Mathematical Sciences; Volume 123; Issue 4 ... The domain part of the email address of all email addresses used by the office of Indian Academy of Sciences, including those of the staff, the journals, various programmes, and Current Science, has changed from 'ias.ernet.in' ...

  13. Exciplex and excimer molecular probes: detection of conformational flip in a myo-inositol chair.

    Science.gov (United States)

    Kadirvel, Manikandan; Arsic, Biljana; Freeman, Sally; Bichenkova, Elena V

    2008-06-07

    2-O-tert-Butyldimethylsilyl-4,6-bis-O-pyrenoyl-myo-inositol-1,3,5-orthoformate (6) and 2-O-tert-butyldimethylsilyl-4-O-[4-(dimethylamino)benzoyl]-6-O-pyrenoyl-myo-inositol-1,3,5-orthoacetate (10) adopt conformationally restricted unstable chairs with five axial substituents. In the symmetrical diester 6, the two pi-stacked pyrenoyl groups are electron acceptor-donor partners, giving a strong intramolecular excimer emission. In the mixed ester 10, the pyrenoyl group is the electron acceptor and the 4-(dimethylamino)benzoyl ester is the electron donor, giving a strong intramolecular exciplex emission. The conformation of the mixed ester 10 was assessed using 1H NMR spectroscopy (1H-NOESY) and computational studies. which showed the minimum inter-centroid distance between the two aromatic systems to be approximately 3.9 A. Upon addition of acid, the orthoformate/orthoacetate trigger in 6 and 10 was cleaved, which caused a switch of the conformation of the myo-inositol ring to the more stable penta-equatorial chair, leading to separation of the aromatic ester groups and loss of excimer and exciplex fluorescence, respectively. This study provides proof of principle for the development of novel fluorescent molecular probes.

  14. Monte Carlo calculations of channeling radiation

    International Nuclear Information System (INIS)

    Bloom, S.D.; Berman, B.L.; Hamilton, D.C.; Alguard, M.J.; Barrett, J.H.; Datz, S.; Pantell, R.H.; Swent, R.H.

    1981-01-01

    Results of classical Monte Carlo calculations are presented for the radiation produced by ultra-relativistic positrons incident in a direction parallel to the (110) plane of Si in the energy range 30 to 100 MeV. The results all show the characteristic CR(channeling radiation) peak in the energy range 20 keV to 100 keV. Plots of the centroid energies, widths, and total yields of the CR peaks as a function of energy show the power law dependences of γ 1 5 , γ 1 7 , and γ 2 5 respectively. Except for the centroid energies and power-law dependence is only approximate. Agreement with experimental data is good for the centroid energies and only rough for the widths. Adequate experimental data for verifying the yield dependence on γ does not yet exist

  15. Trajectory data privacy protection based on differential privacy mechanism

    Science.gov (United States)

    Gu, Ke; Yang, Lihao; Liu, Yongzhi; Liao, Niandong

    2018-05-01

    In this paper, we propose a trajectory data privacy protection scheme based on differential privacy mechanism. In the proposed scheme, the algorithm first selects the protected points from the user’s trajectory data; secondly, the algorithm forms the polygon according to the protected points and the adjacent and high frequent accessed points that are selected from the accessing point database, then the algorithm calculates the polygon centroids; finally, the noises are added to the polygon centroids by the differential privacy method, and the polygon centroids replace the protected points, and then the algorithm constructs and issues the new trajectory data. The experiments show that the running time of the proposed algorithms is fast, the privacy protection of the scheme is effective and the data usability of the scheme is higher.

  16. Crystal structures of 2-benzylamino-4-(4-bromophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile and 2-benzylamino-4-(4-chlorophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    R. A. Nagalakshmi

    2015-01-01

    Full Text Available In the title compounds, C24H22BrN3, (I, and C24H22ClN3, (II, the 2-aminopyridine ring is fused with a cycloheptane ring, which adopts a half-chair conformation. The planes of the phenyl and benzene rings are inclined to that of the central pyridine ring [r.m.s. deviations = 0.0083 (1 and 0.0093 (1 Å for (I and (II, respectively] by 62.47 (17 and 72.51 (14°, respectively, in (I, and by 71.44 (9 and 54.90 (8°, respectively, in (II. The planes of the aromatic rings are inclined to one another by 53.82 (17° in (I and by 58.04 (9° in (II. In the crystals of both (I and (II, pairs of N—H...Nnitrile hydrogen bonds link the molecules, forming inversion dimers with R22(12 ring motifs. In (I, the resulting dimers are connected through C—H...Br hydrogen bonds, forming sheets parallel to (10-1, and π–π interactions [inter-centroid distance = 3.7821 (16 Å] involving inversion-related pyridine rings, forming a three-dimensional network. In (II, the resulting dimers are connected through π–π interactions [inter-centroid distance = 3.771 (2 Å] involving inversion-related pyridine rings, forming a two-dimensional network lying parallel to (001.

  17. Attitudes And Aggressive Actions. Inter-Ethnic Tensions Among German, Turkish And Resettler Adolescents

    Directory of Open Access Journals (Sweden)

    Joachim Bruess

    2014-11-01

    Full Text Available The interaction between immigrants and members of the host society has been and still is an important issue during processes of migration. This study analyses inter-ethnic aggressive antisocial actions among adolescents. A descriptive analysis reveals the frequency of such behaviour among German, Turkish and Resettler (Aussiedler adolescents. The explanatory analysis concentrates on the influence of a attitudes towards violence (justifications, b an approval with social dominance, c bargaining as a conflict resolution strategy, and d trust in the judicial system (a fair treatment according to the law. It is assumed that justifications for violent behaviour and the approval with social dominance are likely to increase inter-ethnic aggressive antisocial actions. In contrast, bargaining as a preference for conflict resolution and trust in the judicial system are supposed to reduce such behaviour. A final comparison reveals whether the explanations are substantial across the groups.

  18. Rich magneto-absorption spectra of AAB-stacked trilayer graphene.

    Science.gov (United States)

    Do, Thi-Nga; Shih, Po-Hsin; Chang, Cheng-Peng; Lin, Chiun-Yan; Lin, Ming-Fa

    2016-06-29

    A generalized tight-binding model is developed to investigate the feature-rich magneto-optical properties of AAB-stacked trilayer graphene. Three intragroup and six intergroup inter-Landau-level (inter-LL) optical excitations largely enrich magneto-absorption peaks. In general, the former are much higher than the latter, depending on the phases and amplitudes of LL wavefunctions. The absorption spectra exhibit single- or twin-peak structures which are determined by quantum modes, LL energy spectra and Fermion distribution. The splitting LLs, with different localization centers (2/6 and 4/6 positions in a unit cell), can generate very distinct absorption spectra. There exist extra single peaks because of LL anti-crossings. AAB, AAA, ABA, and ABC stackings considerably differ from one another in terms of the inter-LL category, frequency, intensity, and structure of absorption peaks. The main characteristics of LL wavefunctions and energy spectra and the Fermi-Dirac function are responsible for the configuration-enriched magneto-optical spectra.

  19. Poly[μ4-glutarato-di-μ3-glutarato-bis(1,10-phenanthrolinediyttrium(III

    Directory of Open Access Journals (Sweden)

    Ling Jin

    2011-08-01

    Full Text Available In the title complex, [Y2(C5H6O43(C12H8N22]n, three glutarate groups and two 1,10-phenanthroline molecules surround the two YIII ions. Both YIII ions are coordinated by two N atoms from the 1,10-phenanthroline, seven O atoms from five glutarate groups in a distorted tricapped trigonal–prismatic geometry. The YIII ions are bridged by glutarate ligands in three modes, forming a layered, polymeric structure. The resulting layers are assembled by π–π stacking interactions [centroid–centroid distances = 3.740 (3 and 3.571 (3 Å] into a three-dimensional supramolecular architecture.

  20. Ethyl 2-[1-(3-methylbutyl-4-phenyl-1H-1,2,3-triazol-5-yl]-2-oxoacetate

    Directory of Open Access Journals (Sweden)

    Muhammad Hafeez

    2013-12-01

    Full Text Available In the title compound, C17H21N3O3, the non-planar (r.m.s. deviation = 0.212 Å ethyl (oxoacetate group is oriented towards the phenyl substituent. The triazole and benzene rings are twisted with respect to each other, making a dihedral angle of 41.69 (6°. In the crystal, molecules are arranged into centrosymmetric R22(10 dimers via pairs of C—H...O interactions involving the ethyl (oxoacetate groups. In addition, the triazole rings show π–π stacking interactions, with their centroids at a distance of 3.745 (2 Å.

  1. MWPC data acquisition in the Brookhaven FASTBUS

    International Nuclear Information System (INIS)

    Black, J.K.; Blatt, S.R.; Campbell, M.C.

    1983-01-01

    For Brookhaven AGS Experiment No. 749, a data acquisition system to accommodate 12, 256 wire multiwire proportional chambers (MWPCs) has been built in the context of the Brookhaven FASTBUS. Information about wires hit or continuous clusters of wires hit is encoded as the centroids of the clusters and number of wires in those clusters. The encoded information is stored in a stack memory in a FASTBUS module where it can be accessed by a FASTBUS Master. Encoding time is less than 4 microseconds. Also, information (in the form of front panel outputs) as to the nature of the data is available in less than 200 nanoseconds

  2. Bis(tetraphenylphosphonium bis[N-(trifluoromethylsulfonyldithiocarbimato(2−-κ2S,S′]zincate(II

    Directory of Open Access Journals (Sweden)

    Paula S. Pinto

    2012-01-01

    Full Text Available The title salt, (C24H20P2[Zn(C2F3NO2S32], consists of a complex dianion and two tetraphenylphosphonium cations. The ZnII ion displays a distorted tetrahedral coordination environment with four S atoms from two S,S′-chelated N-(trifluoromethylsulfonyldithiocarbimate anions. In the crystal, besides the ionic interaction of the oppositely charged ions, intermolecular C—H...O interactions between cations and anions are observed. One of the cations interacts with an inversion-related equivalent by π–π stacking between phenyl rings, with a centroid–centroid distance of 3.932 (4 Å.

  3. (2E-3-(4-Chlorophenyl-1-(4-hydroxyphenylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Jerry P. Jasinski

    2011-04-01

    Full Text Available In the title compound, C15H11ClO2, the dihedral angle between the mean planes of the chlorobenzene and hydroxybenzene rings is 6.5 (6°. The mean plane of the prop-2-en-1-one group makes an angle of 18.0 (1° with the hydroxyphenyl ring and 11.5 (1° with the chlorophenyl ring. The crystal packing is stabilized by intermolecular O—H...O hydrogen bonds, weak C—H...O, C—H...π and π–π stacking interactions [centroid–centroid distances = 3.7771 (7 and 3.6917 (7 Å].

  4. 2,3-Diphenylmaleimide 1-methylpyrrolidin-2-one monosolvate

    Directory of Open Access Journals (Sweden)

    Evgeny Bulatov

    2014-03-01

    Full Text Available In the title compound, C16H11NO2·C5H9NO, the dihedral angles between the maleimide and phenyl rings are 34.7 (2 and 64.8 (2°. In the crystal, the 2,3-diphenylmaleimide and 1-methylpyrrolidin-2-one molecules form centrosymmetrical dimers via pairs of strong N—H...O hydrogen bonds and π–π stacking interactions between the two neighboring maleimide rings [centroid–centroid distance = 3.495 (2 Å]. The dimers are further linked by weak C—H...O and C—H...π hydrogen bonds into a three-dimensional framework.

  5. 2-(5-Bromo-3-isopropylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Pil Ja Seo

    2012-01-01

    Full Text Available The title compound, C13H13BrO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-bromo-3-isopropylsulfanyl-1-benzofuran-2-ylacetate. In the crystal, the carboxyl groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into dimers. These dimers are further packed into stacks along the c axis by intermolecular C—H...π interactions, and by slipped π–π interactions between the furan rings of adjacent molecules [centroid–centroid distance = 3.472 (2 Å, interplanar distance = 3.398 (2 Å and slippage = 0.713 (2 Å].

  6. Characterization of the variability of the South Pacific Convergence Zone using satellite and reanalysis wind product

    Science.gov (United States)

    Lee, T.; Kidwell, A. N.; Jo, Y. H.; Yan, X. H.

    2016-02-01

    The variability of the South Pacific Convergence Zone (SPCZ) is evaluated using ocean surface wind products derived from the QuickSCAT satellite scatterometer for the period of 1999-2009and ERA-Interim atmospheric reanalysis for the period of 1981-2014. From these products, indices were developed to represent the SPCZ strength, area, and centroid location. Excellent agreement is found between the indices derived from the two wind products during the QuikSCAT period in terms of the spatio-temporal structures of the SPCZ. The longer ERA-Interim product is then used to study the variations of SPCZ properties on intraseasonal, seasonal, interannual, and decadal time scales. The SPCZ strength, area, and centroid latitude have a dominant seasonal cycle. In contrast, the SPCZ centroid longitude is dominated by intraseasonal variability due to the influence by the Madden-Julian Oscillation. The SPCZ indices are all correlated with El Niño-Southern Oscillation indices. Interannual and intraseasonal variations of SPCZ strength during strong El Niño are approximately twice as large as the respective seasonal variations. SPCZ strength depends more on the intensity of El Niño rather than the central- vs. eastern-Pacific type. The change from positive to negative Pacific Decadal Oscillation phase around 1999 results in a westward shift of the SPCZ centroid longitude, much smaller interannual swing in centroid latitude, and a decrease in SPCZ area. This study improves the understanding of the variations of the SPCZ on multiple time scales and reveals the variations of SPCZ strength not reported previously. The diagnostics analyses can be used to evaluate climate models.

  7. THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: BIASES IN z  > 1.46 REDSHIFTS DUE TO QUASAR DIVERSITY

    Energy Technology Data Exchange (ETDEWEB)

    Denney, K. D.; Peterson, B. M. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Horne, Keith [SUPA Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom); Brandt, W. N.; Grier, C. J.; Trump, J. R. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Ge, J., E-mail: denney@astronomy.ohio-state.edu [Astronomy Department University of Florida 211 Bryant Space Science Center P.O. Box 112055 Gainesville, FL 32611-2055 (United States)

    2016-12-10

    We use the coadded spectra of 32 epochs of Sloan Digital Sky Survey (SDSS) Reverberation Mapping Project observations of 482 quasars with z  > 1.46 to highlight systematic biases in the SDSS- and Baryon Oscillation Spectroscopic Survey (BOSS)-pipeline redshifts due to the natural diversity of quasar properties. We investigate the characteristics of this bias by comparing the BOSS-pipeline redshifts to an estimate from the centroid of He ii λ 1640. He ii has a low equivalent width but is often well-defined in high-S/N spectra, does not suffer from self-absorption, and has a narrow component which, when present (the case for about half of our sources), produces a redshift estimate that, on average, is consistent with that determined from [O ii] to within the He ii and [O ii] centroid measurement uncertainties. The large redshift differences of ∼1000 km s{sup −1}, on average, between the BOSS-pipeline and He ii-centroid redshifts, suggest there are significant biases in a portion of BOSS quasar redshift measurements. Adopting the He ii-based redshifts shows that C iv does not exhibit a ubiquitous blueshift for all quasars, given the precision probed by our measurements. Instead, we find a distribution of C iv-centroid blueshifts across our sample, with a dynamic range that (i) is wider than that previously reported for this line, and (ii) spans C iv centroids from those consistent with the systemic redshift to those with significant blueshifts of thousands of kilometers per second. These results have significant implications for measurement and use of high-redshift quasar properties and redshifts, and studies based thereon.

  8. Hubble space telescope/advanced camera for surveys confirmation of the dark substructure in A520

    International Nuclear Information System (INIS)

    Jee, M. J.; Hoekstra, H.; Mahdavi, A.; Babul, A.

    2014-01-01

    We present a weak-lensing study of the cluster A520 based on Advanced Camera for Surveys (ACS) data. The excellent data quality provides a mean source density of ∼109 arcmin –2 , which improves both resolution and significance of the mass reconstruction compared to a previous study based on Wide Field Planetary Camera 2 (WFPC2) images. We take care in removing instrumental effects such as the charge trailing due to radiation damage of the detector and the position-dependent point-spread function. This new ACS analysis confirms the previous claims that a substantial amount of dark mass is present between two luminous subclusters where we observe very little light. The centroid of the dark peak in the current ACS analysis is offset to the southwest by ∼1' with respect to the centroid from the WFPC2 analysis. Interestingly, this new centroid is in better agreement with the location where the X-ray emission is strongest, and the mass-to-light ratio estimated with this centroid is much higher (813 ± 78 M ☉ /L R☉ ) than the previous value; the aperture mass with the WFPC2 centroid provides a consistent mass. Although we cannot provide a definite explanation for the dark peak, we discuss a revised scenario, wherein dark matter with a more conventional range (σ DM /m DM < 1 cm 2 g –1 ) of self-interacting cross-section can lead to the detection of this dark substructure. If supported by detailed numerical simulations, this hypothesis opens up the possibility that the A520 system can be used to establish a lower limit of the self-interacting cross-section of dark matter.

  9. THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: BIASES IN z  > 1.46 REDSHIFTS DUE TO QUASAR DIVERSITY

    International Nuclear Information System (INIS)

    Denney, K. D.; Peterson, B. M.; Horne, Keith; Brandt, W. N.; Grier, C. J.; Trump, J. R.; Ho, Luis C.; Ge, J.

    2016-01-01

    We use the coadded spectra of 32 epochs of Sloan Digital Sky Survey (SDSS) Reverberation Mapping Project observations of 482 quasars with z  > 1.46 to highlight systematic biases in the SDSS- and Baryon Oscillation Spectroscopic Survey (BOSS)-pipeline redshifts due to the natural diversity of quasar properties. We investigate the characteristics of this bias by comparing the BOSS-pipeline redshifts to an estimate from the centroid of He ii λ 1640. He ii has a low equivalent width but is often well-defined in high-S/N spectra, does not suffer from self-absorption, and has a narrow component which, when present (the case for about half of our sources), produces a redshift estimate that, on average, is consistent with that determined from [O ii] to within the He ii and [O ii] centroid measurement uncertainties. The large redshift differences of ∼1000 km s −1 , on average, between the BOSS-pipeline and He ii-centroid redshifts, suggest there are significant biases in a portion of BOSS quasar redshift measurements. Adopting the He ii-based redshifts shows that C iv does not exhibit a ubiquitous blueshift for all quasars, given the precision probed by our measurements. Instead, we find a distribution of C iv-centroid blueshifts across our sample, with a dynamic range that (i) is wider than that previously reported for this line, and (ii) spans C iv centroids from those consistent with the systemic redshift to those with significant blueshifts of thousands of kilometers per second. These results have significant implications for measurement and use of high-redshift quasar properties and redshifts, and studies based thereon.

  10. Prevalence and Severity of Off-Centering During Diagnostic CT: Observations From 57,621 CT scans of the Chest, Abdomen, and/or Pelvis.

    Science.gov (United States)

    Akin-Akintayo, Oladunni O; Alexander, Lauren F; Neill, Rebecca; Krupinksi, Elizabeth A; Tang, Xiangyang; Mittal, Pardeep K; Small, William C; Moreno, Courtney C

    2018-02-23

    To determine distances between patient centroid and gantry isocenter during CT imaging of the chest, abdomen, and/or pelvis, and to evaluate differences based on patient gender, scan region, patient position, and gantry aperture. A water phantom and an anthropomorphic phantom were imaged in the centered position in the CT gantry and at several off-centered positions. Additionally, data from 57,621 adult chest, abdomen, and/or pelvic CT acquisitions were evaluated. Data were analyzed with an analysis of variance using the centroid-to-isocenter data as the dependent variable and the other parameters as independent variables. The majority of patient acquisitions (83.7% (48271/57621)) were performed with the patient's centroid positioned below isocenter (mean 1.7 cm below isocenter (SD 1.8 cm); range 12.1 cm below to 7.8 cm above isocenter). Off-centering in the x-axis was less severe (mean 0.01 cm left of isocenter (SD 1.6 cm)). Distance between centroid and isocenter in the y-axis did not differ as a function of sex but did differ based on scan region, patient position, and gantry aperture. Off-centering is common during CT imaging and has been previously demonstrated to impact dose and image quality. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. A NEW APPLICATION OF THE ASTROMETRIC METHOD TO BREAK SEVERE DEGENERACIES IN BINARY MICROLENSING EVENTS

    International Nuclear Information System (INIS)

    Chung, Sun-Ju; Park, Byeong-Gon; Humphrey, Andrew; Ryu, Yoon-Hyun

    2009-01-01

    When a source star is microlensed by one stellar component of widely separated binary stellar components, after finishing the lensing event, the event induced by the other binary star can be additionally detected. In this paper, we investigate whether the close/wide degeneracies in binary lensing events can be resolved by detecting the additional centroid shift of the source images induced by the secondary binary star in wide binary lensing events. From this investigation, we find that if the source star passes close to the Einstein ring of the secondary companion, the degeneracy can be easily resolved by using future astrometric follow-up observations with high astrometric precision. We determine the probability of detecting the additional centroid shift in binary lensing events with high magnification. From this, we find that the degeneracy of binary lensing events with a separation of ∼<20.0 AU can be resolved with a significant efficiency. We also estimate the waiting time for the detection of the additional centroid shift in wide binary lensing events. We find that for typical Galactic lensing events with a separation of ∼<20.0 AU, the additional centroid shift can be detected within 100 days, and thus the degeneracy of those events can be sufficiently broken within a year.

  12. Crystal structures of 2-methoxyisoindoline-1,3-dione, 1,3-dioxoisoindolin-2-yl methyl carbonate and 1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-2-yl methyl carbonate: three anticonvulsant compounds

    Directory of Open Access Journals (Sweden)

    Fortune Ezemobi

    2014-12-01

    Full Text Available The title compounds, C9H7NO3, (1, C10H7NO5, (2, and C14H9NO5, (3, are three potentially anticonvulsant compounds. Compounds (1 and (2 are isoindoline derivatives and (3 is an isoquinoline derivative. Compounds (2 and (3 crystallize with two independent molecules (A and B in their asymmetric units. In all three cases, the isoindoline and benzoisoquinoline moieties are planar [r.m.s. deviations are 0.021 Å for (1, 0.04 and 0.018 Å for (2, and 0.033 and 0.041 Å for (3]. The substituents attached to the N atom are almost perpendicular to the mean planes of the heterocycles, with dihedral angles of 89.7 (3° for the N—O—Cmethyl group in (1, 71.01 (4 and 80.00 (4° for the N—O—C(=OO—Cmethyl groups in (2, and 75.62 (14 and 74.13 (4° for the same groups in (3. In the crystal of (1, there are unusual intermolecular C=O...C contacts of 2.794 (1 and 2.873 (1 Å present in molecules A and B, respectively. There are also C—H...O hydrogen bonds and π–π interactions [inter-centroid distance = 3.407 (3 Å] present, forming slabs lying parallel to (001. In the crystal of (2, the A and B molecules are linked by C—H...O hydrogen bonds, forming slabs parallel to (10-1, which are in turn linked via a number of π–π interactions [the most significant centroid–centroid distances are 3.4202 (7 and 3.5445 (7 Å], forming a three-dimensional structure. In the crystal of (3, the A and B molecules are linked via C—H...O hydrogen bonds, forming a three-dimensional structure, which is consolidated by π–π interactions [the most significant inter-centroid distances are 3.575 (3 and 3.578 (3 Å].

  13. 2,4-Diamino-6-methyl-1,3,5-triazin-1-ium hydrogen oxalate

    Directory of Open Access Journals (Sweden)

    Bohari M. Yamin

    2012-05-01

    Full Text Available The title compound, C4H8N5+·C2HO4−, was obtained from the reaction of oxalic acid and 2,4-diamino-6-methyl-1,3,5-triazine. The protonated triazine ring is essentially planar with a maximum deviation of 0.035 (1 Å, but the hydrogen oxalate anion is less planar, with a maximum deviation of 0.131 (1 Å for both carbonyl O atoms. In the crystal, the ions are linked by intermolecular N—H...O, N—H...N, O—H...O and C—H...O hydrogen bonds, forming a three-dimensional network. Weak π–π [centroid–centroid distance = 3.763 Å] and C—O...π interactions [O...centroid = 3.5300 (16 Å, C—O...centroid = 132.19 (10°] are also present.

  14. 2,6-Diaminopyridinium bis(4-hydroxypyridine-2,6-dicarboxylato-κ3O2,N,O6ferrate(III dihydrate

    Directory of Open Access Journals (Sweden)

    Andya Nemati

    2008-10-01

    Full Text Available The reaction of iron(II sulfate heptahydrate with the proton-transfer compound (pydaH(hypydcH (pyda = pyridine-2,6-diamine; hypydcH2 = 4-hydroxypyridine-2,6-dicarboxylic acid in an aqueous solution led to the formation of the title compound, (C5H8N3[Fe(C7H3NO52]·2H2O. The anion is a six-coordinated complex with a distorted octahedral geometry around the FeIII atom. Extensive intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds, involving the complex anion, (pydaH+ counter-ion and two uncoordinated water molecules, and π–π [centroid-to-centroid distance 3.323 (11 Å] and C—O...π [O–centroid distance 3.150 (15 Å] interactions connect the various components into a supramolecular structure.

  15. Study of position resolution for cathode readout MWPC with measurement of induced charge distribution

    International Nuclear Information System (INIS)

    Chiba, J.; Iwasaki, H.; Kageyama, T.; Kuribayashi, S.; Nakamura, K.; Sumiyoshi, T.; Takeda, T.

    1983-01-01

    A readout technqiue of multiwire proportional chambers by measurement of charges induced on cathode strips, orthogonal to anode wires, requires an algorithm to relate the measured charge distribution to the avalanche position. With given chamber parameters and under the influence of noise, resolution limits depend on the chosen algorithm. We have studied the position resolution obtained by the centroid method and by the charge-ratio method, both using three consecutive cathode strips. While the centroid method uses a single number, the center of gravity of the measured charges, the charge-ratio method uses the ratios of the charges Qsub(i-1)/Qsub(i) and Qsub(i+1)/Qsub(i) where Qsub(i) is the largest. To obtain a given resolution, the charge-ratio method generally allows wider cathode strips and therefore a smaller number of readout channels than the centroid method. (orig.)

  16. Channeling and stability of laser pulses in plasmas

    International Nuclear Information System (INIS)

    Sprangle, P.; Krall, J.; Esarey, E.

    1995-01-01

    A laser pulse propagating in a plasma is found to undergo a combination of hose and modulation instabilities. The coupled equations for the laser beam envelope and centroid are derived and solved for a laser pulse of finite length propagating through either a uniform plasma or preformed plasma density channel. The laser envelope equation describes the pulse self-focusing and optical guiding in plasmas and is used to analyze the self-modulation instability. The laser centroid equation describes the transverse motion of the laser pulse (hosing) in plasmas. Significant coupling between the centroid and envelope motion as well as harmonic generation in the envelope can occur. In addition, the transverse profile of the generated wake field is strongly affected by the laser hose instability. Methods to reduce the laser hose instability are demonstrated. copyright 1995 American Institute of Physics

  17. Normalization based K means Clustering Algorithm

    OpenAIRE

    Virmani, Deepali; Taneja, Shweta; Malhotra, Geetika

    2015-01-01

    K-means is an effective clustering technique used to separate similar data into groups based on initial centroids of clusters. In this paper, Normalization based K-means clustering algorithm(N-K means) is proposed. Proposed N-K means clustering algorithm applies normalization prior to clustering on the available data as well as the proposed approach calculates initial centroids based on weights. Experimental results prove the betterment of proposed N-K means clustering algorithm over existing...

  18. PyCCF: Python Cross Correlation Function for reverberation mapping studies

    Science.gov (United States)

    Sun, Mouyuan; Grier, C. J.; Peterson, B. M.

    2018-05-01

    PyCCF emulates a Fortran program written by B. Peterson for use with reverberation mapping. The code cross correlates two light curves that are unevenly sampled using linear interpolation and measures the peak and centroid of the cross-correlation function. In addition, it is possible to run Monto Carlo iterations using flux randomization and random subset selection (RSS) to produce cross-correlation centroid distributions to estimate the uncertainties in the cross correlation results.

  19. (E)-Methyl 3-(3,4-dimeth­oxy­phen­yl)-2-[(1,3-dioxoisoindolin-2-yl)meth­yl]acrylate

    Science.gov (United States)

    Kannan, D.; Bakthadoss, M.; Lakshmanan, D.; Murugavel, S.

    2012-01-01

    In the title compound, C21H19NO6, the isoindole ring system is essentially planar [maximum deviation = 0.019 (2) Å for the N atom] and is oriented at a dihedral angle of 51.3 (1)° with respect to the benzene ring. The two meth­oxy groups are almost coplanar with the attached benzene ring [C—O—C—C = 3.7 (4) and 4.3 (4)°]. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, mol­ecules are linked through bifurcated C—H⋯(O,O) hydrogen bonds having R 1 2(5) ring motifs, forming chains along the b-axis direction. The crystal packing is further stabilzed by π–π inter­actions [centriod–centroid distance = 3.463 (1) Å]. PMID:22589965

  20. Knowledge Integration and Inter-Disciplinary Communication in Action Research

    Directory of Open Access Journals (Sweden)

    Hahn Heidi Ann

    2014-08-01

    Full Text Available In a plenary talk at WMSCI 2012 entitled "Planning for Action Research: Looking at Practice through a Different Lens," this author asserted that behavioral science practitioners, often "back into" action research – they start out doing a process improvement or intervention and discover something along the way, i.e., generalizable knowledge, that seems worthwhile to share with their community of practice. It was further asserted that, had the efforts been conceived of as research from the outset, the contributions to the body of knowledge would be more robust and the utility of the projects would improve as well. This paper continues on that theme. Action research and process improvement methods are briefly described and compared. A comparison of two Los Alamos National Laboratory engineering ethics training projects – one developed using a process improvement framework, the other using an action research framework – is put forth to provide evidence that use of a research "lens" can enhance behavioral science interventions and the knowledge that may result from them. The linkage between the Specifying Learning and Diagnosing stages of the Action Research Cycle provides one mechanism for integrating the knowledge gained into the product or process being studied and should provide a reinforcing loop that leads to continual improvement. The collaborative relationships among researchers and the individual, group, or organization that is the subject of the imp rovement op p ortunity (the "client", who are likely from very different backgrounds, and the interpretive epistemology that are among the hallmarks of action research also contribute to the quality of the knowledge gained. This paper closes with a discussion of how Inter-Disciplinary Communication is embedded within the action research paradigm and how this likely also enriches the knowledge gained.

  1. Crystal structure of bis(μ-3-nitrobenzoato-κ3O,O′:O;κ3O:O,O′-bis[bis(3-cyanopyridine-κN1(3-nitrobenzoato-κ2O,O′cadmium

    Directory of Open Access Journals (Sweden)

    Tuncer Hökelek

    2017-03-01

    Full Text Available The asymmetric unit of the title compound, [Cd2(C7H4NO44(C6H4N24], contains one CdII atom, two 3-nitrobenzoate (NB anions and two 3-cyanopyridine (CPy ligands. The two CPy ligands act as monodentate N(pyridine-bonding ligands, while the two NB anions act as bidentate ligands through the carboxylate O atoms. The centrosymmetric dinuclear complex is generated by application of inversion symmetry, whereby the CdII atoms are bridged by the carboxylate O atoms of two symmetry-related NB anions, thus completing the distorted N2O5 pentagonal–bipyramidal coordination sphere of each CdII atom. The benzene and pyridine rings are oriented at dihedral angles of 10.02 (7 and 5.76 (9°, respectively. In the crystal, C—H...N hydrogen bonds link the molecules, enclosing R22(26 ring motifs, in which they are further linked via C—H...O hydrogen bonds, resulting in a three-dimensional network. In addition, π–π stacking interactions between parallel benzene rings and between parallel pyridine rings of adjacent molecules [shortest centroid-to-centroid distances = 3.885 (1 and 3.712 (1 Å, respectively], as well as a weak C—H...π interaction, may further stabilize the crystal structure.

  2. SU-F-J-109: Generate Synthetic CT From Cone Beam CT for CBCT-Based Dose Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H; Barbee, D; Wang, W; Pennell, R; Hu, K; Osterman, K [Department of Radiation Oncology, NYU Langone Medical Center, New York, NY (United States)

    2016-06-15

    Purpose: The use of CBCT for dose calculation is limited by its HU inaccuracy from increased scatter. This study presents a method to generate synthetic CT images from CBCT data by a probabilistic classification that may be robust to CBCT noise. The feasibility of using the synthetic CT for dose calculation is evaluated in IMRT for unilateral H&N cancer. Methods: In the training phase, a fuzzy c-means classification was performed on HU vectors (CBCT, CT) of planning CT and registered day-1 CBCT image pair. Using the resulting centroid CBCT and CT values for five classified “tissue” types, a synthetic CT for a daily CBCT was created by classifying each CBCT voxel to obtain its probability belonging to each tissue class, then assigning a CT HU with a probability-weighted summation of the classes’ CT centroids. Two synthetic CTs from a CBCT were generated: s-CT using the centroids from classification of individual patient CBCT/CT data; s2-CT using the same centroids for all patients to investigate the applicability of group-based centroids. IMRT dose calculations for five patients were performed on the synthetic CTs and compared with CT-planning doses by dose-volume statistics. Results: DVH curves of PTVs and critical organs calculated on s-CT and s2-CT agree with those from planning-CT within 3%, while doses calculated with heterogeneity off or on raw CBCT show DVH differences up to 15%. The differences in PTV D95% and spinal cord max are 0.6±0.6% and 0.6±0.3% for s-CT, and 1.6±1.7% and 1.9±1.7% for s2-CT. Gamma analysis (2%/2mm) shows 97.5±1.6% and 97.6±1.6% pass rates for using s-CTs and s2-CTs compared with CT-based doses, respectively. Conclusion: CBCT-synthesized CTs using individual or group-based centroids resulted in dose calculations that are comparable to CT-planning dose for unilateral H&N cancer. The method may provide a tool for accurate dose calculation based on daily CBCT.

  3. SU-F-J-109: Generate Synthetic CT From Cone Beam CT for CBCT-Based Dose Calculation

    International Nuclear Information System (INIS)

    Wang, H; Barbee, D; Wang, W; Pennell, R; Hu, K; Osterman, K

    2016-01-01

    Purpose: The use of CBCT for dose calculation is limited by its HU inaccuracy from increased scatter. This study presents a method to generate synthetic CT images from CBCT data by a probabilistic classification that may be robust to CBCT noise. The feasibility of using the synthetic CT for dose calculation is evaluated in IMRT for unilateral H&N cancer. Methods: In the training phase, a fuzzy c-means classification was performed on HU vectors (CBCT, CT) of planning CT and registered day-1 CBCT image pair. Using the resulting centroid CBCT and CT values for five classified “tissue” types, a synthetic CT for a daily CBCT was created by classifying each CBCT voxel to obtain its probability belonging to each tissue class, then assigning a CT HU with a probability-weighted summation of the classes’ CT centroids. Two synthetic CTs from a CBCT were generated: s-CT using the centroids from classification of individual patient CBCT/CT data; s2-CT using the same centroids for all patients to investigate the applicability of group-based centroids. IMRT dose calculations for five patients were performed on the synthetic CTs and compared with CT-planning doses by dose-volume statistics. Results: DVH curves of PTVs and critical organs calculated on s-CT and s2-CT agree with those from planning-CT within 3%, while doses calculated with heterogeneity off or on raw CBCT show DVH differences up to 15%. The differences in PTV D95% and spinal cord max are 0.6±0.6% and 0.6±0.3% for s-CT, and 1.6±1.7% and 1.9±1.7% for s2-CT. Gamma analysis (2%/2mm) shows 97.5±1.6% and 97.6±1.6% pass rates for using s-CTs and s2-CTs compared with CT-based doses, respectively. Conclusion: CBCT-synthesized CTs using individual or group-based centroids resulted in dose calculations that are comparable to CT-planning dose for unilateral H&N cancer. The method may provide a tool for accurate dose calculation based on daily CBCT.

  4. Minimizing End-to-End Interference in I/O Stacks Spanning Shared Multi-Level Buffer Caches

    Science.gov (United States)

    Patrick, Christina M.

    2011-01-01

    This thesis presents an end-to-end interference minimizing uniquely designed high performance I/O stack that spans multi-level shared buffer cache hierarchies accessing shared I/O servers to deliver a seamless high performance I/O stack. In this thesis, I show that I can build a superior I/O stack which minimizes the inter-application interference…

  5. Optimal deep neural networks for sparse recovery via Laplace techniques

    OpenAIRE

    Limmer, Steffen; Stanczak, Slawomir

    2017-01-01

    This paper introduces Laplace techniques for designing a neural network, with the goal of estimating simplex-constraint sparse vectors from compressed measurements. To this end, we recast the problem of MMSE estimation (w.r.t. a pre-defined uniform input distribution) as the problem of computing the centroid of some polytope that results from the intersection of the simplex and an affine subspace determined by the measurements. Owing to the specific structure, it is shown that the centroid ca...

  6. Assessment of auditory impression of the coolness and warmness of automotive HVAC noise.

    Science.gov (United States)

    Nakagawa, Seiji; Hotehama, Takuya; Kamiya, Masaru

    2017-07-01

    Noise induced by a heating, ventilation and air conditioning (HVAC) system in a vehicle is an important factor that affects the comfort of the interior of a car cabin. Much effort has been devoted to reduce noise levels, however, there is a need for a new sound design that addresses the noise problem from a different point of view. In this study, focusing on the auditory impression of automotive HVAC noise concerning coolness and warmness, psychoacoustical listening tests were performed using a paired comparison technique under various conditions of room temperature. Five stimuli were synthesized by stretching the spectral envelopes of recorded automotive HVAC noise to assess the effect of the spectral centroid, and were presented to normal-hearing subjects. Results show that the spectral centroid significantly affects the auditory impression concerning coolness and warmness; a higher spectral centroid induces a cooler auditory impression regardless of the room temperature.

  7. Characterization of the variability of the South Pacific Convergence Zone using satellite and reanalysis wind products

    Science.gov (United States)

    Kidwell, Autumn; Lee, Tong; Jo, Young-Heon; Yan, Xiao-hai

    2016-04-01

    The South Pacific Convergence Zone (SPCZ), the largest rain band worldwide during austral summer, is important to atmospheric circulation (including cyclone genesis) and ocean circulation. Previous studies of the SPCZ have focused on parameters such as outgoing longwave radiation or precipitation. However, wind convergence is fundamental causing the variations of these parameters. In this study, the SPCZ variability is examined using ocean surface wind products derived from NASA's QuickSCAT (1999-2009) and ESA's ASCAT (2007 onward) satellite scatterometers and ERA-Interim atmospheric reanalysis (1981 onward). From these products, indices were developed to characterize the SPCZ strength, area, and centroid location. Excellent agreement is found in terms of the temporal variations of the indices derived from the satellites and reanalysis wind products, despite some small differences in the time-mean SPCZ strength. The SPCZ strength, area, and centroid latitude have a dominant seasonal cycle. In contrast, the SPCZ centroid longitude is dominated by intraseasonal variability due to the influence by the Madden-Julian Oscillation. The SPCZ indices are all correlated with El Niño-Southern Oscillation indices. Interannual and intraseasonal variations of SPCZ strength during strong El Niño are approximately twice as large as the respective seasonal variations. SPCZ strength depends more on the intensity of El Niño rather than the central- vs. eastern-Pacific type. The longer ERA-Interim product is also used to examine decadal variations of the SPCZ indices. The change from positive to negative Pacific Decadal Oscillation phase around 1999 resulted in a westward shift of the SPCZ centroid longitude, much smaller interannual swing in centroid latitude, and a decrease in SPCZ area. This study improves the understanding of the variations of the SPCZ on multiple time scales and reveals the variations of SPCZ strength not reported previously. The diagnostics analyses can be

  8. Estimating the accuracy of geographical imputation

    Directory of Open Access Journals (Sweden)

    Boscoe Francis P

    2008-01-01

    Full Text Available Abstract Background To reduce the number of non-geocoded cases researchers and organizations sometimes include cases geocoded to postal code centroids along with cases geocoded with the greater precision of a full street address. Some analysts then use the postal code to assign information to the cases from finer-level geographies such as a census tract. Assignment is commonly completed using either a postal centroid or by a geographical imputation method which assigns a location by using both the demographic characteristics of the case and the population characteristics of the postal delivery area. To date no systematic evaluation of geographical imputation methods ("geo-imputation" has been completed. The objective of this study was to determine the accuracy of census tract assignment using geo-imputation. Methods Using a large dataset of breast, prostate and colorectal cancer cases reported to the New Jersey Cancer Registry, we determined how often cases were assigned to the correct census tract using alternate strategies of demographic based geo-imputation, and using assignments obtained from postal code centroids. Assignment accuracy was measured by comparing the tract assigned with the tract originally identified from the full street address. Results Assigning cases to census tracts using the race/ethnicity population distribution within a postal code resulted in more correctly assigned cases than when using postal code centroids. The addition of age characteristics increased the match rates even further. Match rates were highly dependent on both the geographic distribution of race/ethnicity groups and population density. Conclusion Geo-imputation appears to offer some advantages and no serious drawbacks as compared with the alternative of assigning cases to census tracts based on postal code centroids. For a specific analysis, researchers will still need to consider the potential impact of geocoding quality on their results and evaluate

  9. Monitoring Population Evolution in China Using Time-Series DMSP/OLS Nightlight Imagery

    Directory of Open Access Journals (Sweden)

    Sisi Yu

    2018-01-01

    Full Text Available Accurate and detailed monitoring of population distribution and evolution is of great significance in formulating a population planning strategy in China. The Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS nighttime lights time-series (NLT image products offer a good opportunity for detecting the population distribution owing to its high correlation to human activities. However, their detection capability is greatly limited owing to a lack of in-flight calibration. At present, the synergistic use of systematically-corrected NLT products and population spatialization is rarely applied. This work proposed a methodology to improve the application precision and versatility of NLT products, explored a feasible approach to quantitatively spatialize the population to grid units of 1 km × 1 km , and revealed the spatio-temporal characteristics of population distribution from 2000 to 2010. Results indicated that, (1 after inter-calibration, geometric, incompatibility and discontinuity corrections, and adjustment based on vegetation information, the incompatibility and discontinuity of NTL products were successfully solved. Accordingly, detailed actual residential areas and luminance differences between the urban core and the peripheral regions could be obtained. (2 The population spatialization method could effectively acquire population information at per km 2 with high accuracy and exhibit more details in the evolution of population distribution. (3 Obvious differences in spatio-temporal characteristics existed in four economic regions, from the aspects of population distribution and dynamics, as well as population-weighted centroids. The eastern region was the most populous with the largest increased magnitude, followed by the central, northeastern, and western regions. The population-weighted centroids of the eastern, western, and northeastern regions moved along the southwest direction, while the population

  10. Project InterActions: A Multigenerational Robotic Learning Environment

    Science.gov (United States)

    Bers, Marina U.

    2007-12-01

    This paper presents Project InterActions, a series of 5-week workshops in which very young learners (4- to 7-year-old children) and their parents come together to build and program a personally meaningful robotic project in the context of a multigenerational robotics-based community of practice. The goal of these family workshops is to teach both parents and children about the mechanical and programming aspects involved in robotics, as well as to initiate them in a learning trajectory with and about technology. Results from this project address different ways in which parents and children learn together and provide insights into how to develop educational interventions that would educate parents, as well as children, in new domains of knowledge and skills such as robotics and new technologies.

  11. 5,6-Dimethyl-1,2,9,10-tetrahydropyrano[3,2-f]chromene-3,8-dione

    Directory of Open Access Journals (Sweden)

    Shailesh K. Goswami

    2012-07-01

    Full Text Available The title molecule, C14H14O4, lies on a twofold rotation axis that bisects the central benzene ring, with only one half-molecule in the asymmetric unit. The pyranone systems adopt distorted twist- boat conformations, with the two methylene C atoms displaced by 0.537 (1 and 0.163 (2 Å from the best-fit plane through the remaining five C and O atoms (r.m.s. deviation = 0.073 Å. In the crystal, bifurcated C—H...(O,O hydrogen bonds link pairs of adjacent molecules in an obverse fashion, stacking molecules along c. These contacts are further stabilized by very weak π–π interactions between adjacent benzene rings with centroid–centroid distances of 4.1951 (4 Å. Additional C—H...O contacts link these stacks, giving a three-dimensional network.

  12. Alignment error of mirror modules of advanced telescope for high-energy astrophysics due to wavefront aberrations

    Science.gov (United States)

    Zocchi, Fabio E.

    2017-10-01

    One of the approaches that is being tested for the integration of the mirror modules of the advanced telescope for high-energy astrophysics x-ray mission of the European Space Agency consists in aligning each module on an optical bench operated at an ultraviolet wavelength. The mirror module is illuminated by a plane wave and, in order to overcome diffraction effects, the centroid of the image produced by the module is used as a reference to assess the accuracy of the optical alignment of the mirror module itself. Among other sources of uncertainty, the wave-front error of the plane wave also introduces an error in the position of the centroid, thus affecting the quality of the mirror module alignment. The power spectral density of the position of the point spread function centroid is here derived from the power spectral density of the wave-front error of the plane wave in the framework of the scalar theory of Fourier diffraction. This allows the defining of a specification on the collimator quality used for generating the plane wave starting from the contribution to the error budget allocated for the uncertainty of the centroid position. The theory generally applies whenever Fourier diffraction is a valid approximation, in which case the obtained result is identical to that derived by geometrical optics considerations.

  13. Stochastic sampling of the RNA structural alignment space.

    Science.gov (United States)

    Harmanci, Arif Ozgun; Sharma, Gaurav; Mathews, David H

    2009-07-01

    A novel method is presented for predicting the common secondary structures and alignment of two homologous RNA sequences by sampling the 'structural alignment' space, i.e. the joint space of their alignments and common secondary structures. The structural alignment space is sampled according to a pseudo-Boltzmann distribution based on a pseudo-free energy change that combines base pairing probabilities from a thermodynamic model and alignment probabilities from a hidden Markov model. By virtue of the implicit comparative analysis between the two sequences, the method offers an improvement over single sequence sampling of the Boltzmann ensemble. A cluster analysis shows that the samples obtained from joint sampling of the structural alignment space cluster more closely than samples generated by the single sequence method. On average, the representative (centroid) structure and alignment of the most populated cluster in the sample of structures and alignments generated by joint sampling are more accurate than single sequence sampling and alignment based on sequence alone, respectively. The 'best' centroid structure that is closest to the known structure among all the centroids is, on average, more accurate than structure predictions of other methods. Additionally, cluster analysis identifies, on average, a few clusters, whose centroids can be presented as alternative candidates. The source code for the proposed method can be downloaded at http://rna.urmc.rochester.edu.

  14. Mononuclear late first row transition metal complexes of ONO donor hydrazone ligand: Synthesis, characterization, crystallographic insight, in vivo and in vitro anti-inflammatory activity

    Science.gov (United States)

    Kendur, Umashri; Chimmalagi, Geeta H.; Patil, Sunil M.; Gudasi, Kalagouda B.; Frampton, Christopher S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.

    2018-02-01

    Air and moisture stable coordination compounds of late first row transition metal ions, viz., Co(II), Ni(II), Cu(II) and Zn(II) with a newly designed ligand, (E)-2-amino-N'-(1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl)ethylidene)benzohydrazide (H2L) were prepared and extensively characterized using various spectro-analytical techniques. The ligand acts both in mono as well as doubly deprotonated manner. The ligand to metal stoichiometry was found to be 1:2 in case of complexes using chloride salts, whereas 1:1 in case of copper (II) complex using its acetate salt. The molecular structures of H2L, nickel and copper complexes were unambiguously determined by single-crystal X-ray diffraction studies reveal that H2L exists in a zwitterionic form while copper complex has copper centre in a distorted square planar environment. On the other hand, cobalt, nickel and zinc complexes display distorted octahedral coordination around the metal ion. In case of [Ni(HL)2].H2O, intramolecular Csbnd H⋯π stacking interaction were observed between the centroid of five membered chelate ring and phenyl proton C5sbnd H5 and intermolecular Csbnd H⋯π stacking interaction between the centroid of phenyl ring, dehydroacetic acid (DHA) ring and phenyl protons. The [Cu(L)DMF] complex is stabilized by intramolecular hydrogen bonding N1H⋯N2 and by intermolecular hydrogen bonding N1H⋯O4. Intermolecular interactions were investigated by Hirshfeld surfaces. Further, H2L and its metal complexes were screened for their in vivo and in vitro anti-inflammatory activities. The activity of the ligand has enhanced on coordination with transition metals. The tested compounds have shown excellent activity, which is almost equipotent to the standard used in the study.

  15. Putting fossils on the map: Applying a geographical information system to heritage resources

    CSIR Research Space (South Africa)

    Van der Walt, M

    2015-11-01

    Full Text Available identifiers,14 particularly farm names, rather than coordinates. Converting the data required rigorous ‘cleaning’, correction of spelling errors and standardisation of content to permit queries. Farm names with their corresponding farm numbers were aligned..., as the majority of records had only a farm name for the locality, a spatial database had to be created to allow records to be imported automatically to specific localities referenced as farm centroids. A farm centroid is the calculated gravitational centre...

  16. Theophylline–gentisic acid (1/1

    Directory of Open Access Journals (Sweden)

    Srinivasulu Aitipamula

    2009-09-01

    Full Text Available In the title 1:1 cocrystal, C7H8N4O2·C7H6O4, the anti-asthmatic drug theophylline (systematic name: 1,3-dimethyl-7H-purine-2,6-dione and a non-steroidal anti-inflammatory drug, gentisic acid (systematic name: 2,5-dihydroxybenzoic acid crystallize together, forming two-dimensional hydrogen-bonded sheets involving N—H...O and O—H...N hydrogen bonds. The overall crystal packing features π–π stacking interactions [centroid–centroid distance = 3.348 (1 Å]. The cocrystal described herein belongs to the class of pharmaceutical cocrystals involving two active pharmaceutical ingredients which has been relatively unexplored to date.

  17. 2,4-Dichloro-N-o-tolylbenzamide

    Directory of Open Access Journals (Sweden)

    Aamer Saeed

    2009-07-01

    Full Text Available In the title compound, C14H11Cl2NO, the central C—C(O—N—C amide unit makes dihedral angles of 68.71 (11 and 54.92 (12°, respectively, with the dichlorobenzene and tolyl rings. The two aromatic rings are inclined at 16.25 (17°. In the crystal, N—H...O hydrogen bonds link molecules into zigzag chains propagating in [001]. C—H...Cl contacts link these chains and additional C—H...O contacts generate stacks down b. Weak C—H...π and C—Cl...π interactions [Cl...centroid distance = 3.5422 (15 Å] may also stabilize the structure.

  18. Bis(2,6-dimethylanilinium diaquabis(dihydrogen diphosphato-κ2O,O′cobaltate(II

    Directory of Open Access Journals (Sweden)

    Ahlem Ben Saad

    2014-03-01

    Full Text Available In the title compound, (C8H12N2[Co(H2P2O72(H2O2], the Co2+ ion lies on a crystallographic inversion centre and adopts a slightly distorted octahedral CoO6 coordination geometry arising from two chelating diphosphate [H2P2O7]2− ligands and two trans water molecules. In the crystal, the components are linked by O—H...O, N—H...O and C—H...O hydrogen bonds and weak aromatic π–π stacking [shortest centroid–centroid separation = 3.778 (2 Å] interactions. (001 layers of alternating organic cations and complex inorganic anions are apparent.

  19. 4-(Prop-2-yn-1-yloxybenzene-1,2-dicarbonitrile

    Directory of Open Access Journals (Sweden)

    Yee Jan Chin

    2012-07-01

    Full Text Available In the title compound, C11H6N2O, the complete molecule is generated by the application of crystallographic twofold symmetry (the molecule is disordered about this axis. The prop-2-yn-1-yl residue is slightly twisted out of the plane of the benzene ring [C—O—C—C torsion angle = 173.1 (3°] and is orientated away from the nitrile substituents. In the crystal, supramolecular chains along the a axis, arising from C—H...N interactions, are connected into stacks along the c axis by π–π interactions between the benzene rings [centroid–centroid distance = 3.6978 (6 Å = length of the c axis].

  20. Hemi(4,4′-bipyridinium hexafluoridophosphate bis(4-aminobenzoic acid 4,4′-bipyridine monohydrate

    Directory of Open Access Journals (Sweden)

    Yi-Fan Luo

    2009-02-01

    Full Text Available In the title compound, 0.5C10H10N22+·PF6−·C10H8N2·2C7H7NO2·H2O, the cation is located on a center of symmetry. The crystal structure is determined by a complex three-dimensional network of intermolecular O—H...O, O—H...N, N—H...N and N—H...F hydrogen bonds. π–π stacking interactions between neighboring pyridyl rings are also present; the centroid–centroid distance is 3.643 (5 Å. The hexafluoridophosphate anion is disordered over two positions with site-occupancy factors of ca 0.6 and 0.4.

  1. Crystal structure of 1-(2,4-dihydroxy-6-methylphenylethanone

    Directory of Open Access Journals (Sweden)

    Samran Prabpai

    2015-08-01

    Full Text Available The title compound, C9H10O3, is a bioactive secondary metabolite, isolated from the endophytic fungus Nodulisporium sp. The compound exhibits an intramolecular O—H...O hydrogen bond between the phenolic H atom and the carbonyl O atom of the adjacent acetyl group. In the crystal, molecules are linked by hydrogen bonds involving the 4-phenolic H atom and a symmetry-related carbonyl O atom of a neighboring molecule, resulting in extended supramolecular chains along the a-axis direction. Aromatic π–π stacking interactions between the nearly parallel benzene rings of adjacent chains [centroid–centroid distance = 3.7478 (8 Å] further stabilize the three-dimensional supramolecular framework.

  2. Crystal structure of 3,4-dichloroanilinium hydrogen phthalate

    Directory of Open Access Journals (Sweden)

    Muhammad Shahid

    2015-07-01

    Full Text Available In the title salt, C6H6Cl2N+·C8H5O4−, the carboxylic acid and carboxylate groups of the anion form dihedral angles of 20.79 (19 and 74.76 (14°, respectively, with the plane of the benzene ring. In the crystal, molecules are assembled into a two-dimensional polymeric network parallel to (100 via N—H...O and O—H...O hydrogen bonds. In addition, within the layer, there are π–π stacking interactions between the benzene rings of the cation and the anion [centroid–centroid distance = 3.6794 (17 Å]. A weak C—H...O interaction is also observed.

  3. Mechanochemical synthesis and crystal structure of a 1:2 co-crystal of 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecane (TATU and 4-chloro-3,5-dimethylphenol

    Directory of Open Access Journals (Sweden)

    Augusto Rivera

    2016-11-01

    Full Text Available Solvent-free treatment of 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecano (TATU with 4-chloro-3,5-dimethylphenol led to the formation of the title co-crystal, C7H14N4·2C8H9ClO. The asymmetric unit contains one aminal cage molecule and two phenol molecules linked via two O—H...N hydrogen bonds. In the aminal cage, the N–CH2–CH2–N unit is slightly distorted from a syn periplanar geometry. Aromatic π–π stacking between the benzene rings from two different neighbouring phenol molecules [centroid–centroid distance = 4.0570 (11 Å] consolidates the crystal packing.

  4. Crystal structure of 4-methoxy-N-[(pyrrolidin-1-ylcarbothioyl]benzamide

    Directory of Open Access Journals (Sweden)

    Khairi Suhud

    2015-04-01

    Full Text Available In the title compound, C13H16N2O2S, the pyrrolidine ring has a twisted conformation on the central –CH2–CH2– bond. Its mean plane is inclined to the 4-methoxybenzoyl ring by 72.79 (15°. In the crystal, molecules are linked by N—H...O and C—H...O hydrogen bonds to the same O-atom acceptor, forming chains along [001]. The chains are linked via slipped parallel π–π interactions [inter-centroid distance = 3.7578 (13 Å], forming undulating slabs parallel to (100.

  5. Behavior of a nuclear power plant ventilation stack for wind loads

    International Nuclear Information System (INIS)

    Venkatachalapathy, V.

    2012-01-01

    This paper describes behavior of self supporting tall reinforced concrete (RC) ventilation stack of a nuclear power plant (NPP) for wind loads. Since the static and equivalent dynamic wind loads are inter-dependant on overall size of the stack, proper sizing of the stack geometry is important for reducing wind loads. The present study investigated the influence of engineered backfill soil on lateral response of ventilation stack. Ignoring backfill soil stiffness up to ground height does not allow to predict actual critical wind velocity causing across wind oscillation. The results show that proposed modification in the stack geometry modeled using 2D beam-spring elements is economical than that of single tapered geometry. Shaft diameter reduced in the proposed geometry indicates that there is a scope for overall space savings in the NPP layout. (author)

  6. Hartman Testing of X-Ray Telescopes

    Science.gov (United States)

    Saha, Timo T.; Biskasch, Michael; Zhang, William W.

    2013-01-01

    Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

  7. Fatigue Feature Extraction Analysis based on a K-Means Clustering Approach

    Directory of Open Access Journals (Sweden)

    M.F.M. Yunoh

    2015-06-01

    Full Text Available This paper focuses on clustering analysis using a K-means approach for fatigue feature dataset extraction. The aim of this study is to group the dataset as closely as possible (homogeneity for the scattered dataset. Kurtosis, the wavelet-based energy coefficient and fatigue damage are calculated for all segments after the extraction process using wavelet transform. Kurtosis, the wavelet-based energy coefficient and fatigue damage are used as input data for the K-means clustering approach. K-means clustering calculates the average distance of each group from the centroid and gives the objective function values. Based on the results, maximum values of the objective function can be seen in the two centroid clusters, with a value of 11.58. The minimum objective function value is found at 8.06 for five centroid clusters. It can be seen that the objective function with the lowest value for the number of clusters is equal to five; which is therefore the best cluster for the dataset.

  8. Maximum likelihood positioning for gamma-ray imaging detectors with depth of interaction measurement

    International Nuclear Information System (INIS)

    Lerche, Ch.W.; Ros, A.; Monzo, J.M.; Aliaga, R.J.; Ferrando, N.; Martinez, J.D.; Herrero, V.; Esteve, R.; Gadea, R.; Colom, R.J.; Toledo, J.; Mateo, F.; Sebastia, A.; Sanchez, F.; Benlloch, J.M.

    2009-01-01

    The center of gravity algorithm leads to strong artifacts for gamma-ray imaging detectors that are based on monolithic scintillation crystals and position sensitive photo-detectors. This is a consequence of using the centroids as position estimates. The fact that charge division circuits can also be used to compute the standard deviation of the scintillation light distribution opens a way out of this drawback. We studied the feasibility of maximum likelihood estimation for computing the true gamma-ray photo-conversion position from the centroids and the standard deviation of the light distribution. The method was evaluated on a test detector that consists of the position sensitive photomultiplier tube H8500 and a monolithic LSO crystal (42mmx42mmx10mm). Spatial resolution was measured for the centroids and the maximum likelihood estimates. The results suggest that the maximum likelihood positioning is feasible and partially removes the strong artifacts of the center of gravity algorithm.

  9. Maximum likelihood positioning for gamma-ray imaging detectors with depth of interaction measurement

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Grupo de Sistemas Digitales, ITACA, Universidad Politecnica de Valencia, 46022 Valencia (Spain)], E-mail: lerche@ific.uv.es; Ros, A. [Grupo de Fisica Medica Nuclear, IFIC, Universidad de Valencia-Consejo Superior de Investigaciones Cientificas, 46980 Paterna (Spain); Monzo, J.M.; Aliaga, R.J.; Ferrando, N.; Martinez, J.D.; Herrero, V.; Esteve, R.; Gadea, R.; Colom, R.J.; Toledo, J.; Mateo, F.; Sebastia, A. [Grupo de Sistemas Digitales, ITACA, Universidad Politecnica de Valencia, 46022 Valencia (Spain); Sanchez, F.; Benlloch, J.M. [Grupo de Fisica Medica Nuclear, IFIC, Universidad de Valencia-Consejo Superior de Investigaciones Cientificas, 46980 Paterna (Spain)

    2009-06-01

    The center of gravity algorithm leads to strong artifacts for gamma-ray imaging detectors that are based on monolithic scintillation crystals and position sensitive photo-detectors. This is a consequence of using the centroids as position estimates. The fact that charge division circuits can also be used to compute the standard deviation of the scintillation light distribution opens a way out of this drawback. We studied the feasibility of maximum likelihood estimation for computing the true gamma-ray photo-conversion position from the centroids and the standard deviation of the light distribution. The method was evaluated on a test detector that consists of the position sensitive photomultiplier tube H8500 and a monolithic LSO crystal (42mmx42mmx10mm). Spatial resolution was measured for the centroids and the maximum likelihood estimates. The results suggest that the maximum likelihood positioning is feasible and partially removes the strong artifacts of the center of gravity algorithm.

  10. Tests of the methods of analysis of picosecond lifetimes and measurement of the half-life of the 569.6 keV level in 207Pb

    International Nuclear Information System (INIS)

    Lima, E. de; Kawakami, H.; Lima, A. de; Hichwa, R.; Ramayya, A.V.; Hamilton, J.H.; Dunn, W.; Kim, H.J.

    1978-01-01

    Customarily one extracts the half-life of the nuclear state from a delayed time spectrum by an analysis of the centroid shift, the slope and lately by the convolution method. Recently there have been two formulas relating the centroid shift to the half-life of the nuclear state. These two procedures can give different results for the half-life when Tsub(1/2) the same order or less than the time width of one channel. An extensive investigation of these two formulas and precedures has been made by measuring the half-life of the first excited state in 207 Pb at 569.6 keV. This analysis confirms Bay's formula relating the centroid shift to the half-life of the state. The half-life of the 569.6 keV level in 207 Pb is measured to be (129+-3) ps in excellent agreement with Weisskopf's single particle estimate of 128 ps for an E2 transition. (Auth.)

  11. 3-Diazo-N-[(2S-1-hydroxypropan-2-yl]-2-oxopropanamide

    Directory of Open Access Journals (Sweden)

    Xiao-na Chen

    2011-05-01

    Full Text Available In the title compound, C6H9N3O3, the 3-diazo-2-oxopropanamide section of the molecule is nearly planar, with a maximum deviation of 0.025 (1 Å from the mean plane of its constituent atoms. The diazo C=N=N angle is 178.0 (3°. In the crystal, pairs of intermolecular O—H...O and N—H...O hydrogen bonds link the molecules into infinite double chains along the [100] direction. The double chains are additionally stabilized by weak C—H...O contacts with C...O distances of 3.039 (3 Å. Neighboring double chains in turn interact with each other through π–π stacking interactions [centroid–centroid distance of the 3-diazo-2-oxopropanamide units = 3.66 (6 Å] to form infinite stacks along the b axis. Molecules from neighboring stacks interdigitate with each other in the c-axis direction, thus leading to an interwoven three-dimensional network held together by O—H...O, N—H...O and C—H...O interactions and π–π stacking.

  12. Micro-XANES Determination Fe Speciation in Natural Basalts at Mantle-Relevant fO2

    Science.gov (United States)

    Fischer, R.; Cottrell, E.; Lanzirotti, A.; Kelley, K. A.

    2007-12-01

    We demonstrate that the oxidation state of iron (Fe3+/ΣFe) can be determined with a precision of ±0.02 (10% relative) on natural basalt glasses at mantle-relevant fO2 using Fe K-edge X-ray absorption near edge structure (XANES) spectroscopy. This is equivalent to ±0.25 log unit resolution relative to the QFM buffer. Precise determination of the oxidation state over this narrow range (Fe3+/ΣFe=0.06-0.30) and at low fO2 (down to QFM-2) relies on appropriate standards, high spectral resolution, and highly reproducible methods for extracting the pre-edge centroid position. We equilibrated natural tholeiite powder in a CO/CO2 gas mixing furnace at 1350°C from QFM-3 to QFM+2 to create six glasses of known Fe3+/ΣFe, independently determined by Mössbauer spectroscopy. XANES spectra were collected at station X26A at NSLS, Brookhaven Natl. Lab, in fluorescence mode (9 element Ge array detector) using both Si(111) and Si(311) monochromators. Generally, the energy position of the 1s→3d (pre-edge) transition centroid is the most sensitive monitor of Fe oxidation state using XANES. For the mixture of Fe oxidation states in these glasses and the resulting coordination geometries, the pre-edge spectra are best defined by two multiple 3d crystal field transitions. The Si(311) monochromator, with higher energy resolution, substantially improved spectral resolution for the 1s→3d transition. Dwell times of 5s at 0.1eV intervals across the pre-edge region yielded spectra with the 1s→3d transition peaks clearly resolved. The pre-edge centroid position is highly sensitive to the background subtraction and peak fitting procedures. Differences in fitting models result in small but significant differences in the calculated peak area of each pre-edge multiplet, and the relative contribution of each peak to the calculated centroid. We assessed several schemes and obtained robust centroid positions by simultaneously fitting the background with a damped harmonic oscillator (DHO

  13. Fast Template-based Shape Analysis using Diffeomorphic Iterative Centroid

    OpenAIRE

    Cury , Claire; Glaunès , Joan Alexis; Chupin , Marie; Colliot , Olivier

    2014-01-01

    International audience; A common approach for the analysis of anatomical variability relies on the estimation of a representative template of the population, followed by the study of this population based on the parameters of the deformations going from the template to the population. The Large Deformation Diffeomorphic Metric Mapping framework is widely used for shape analysis of anatomical structures, but computing a template with such framework is computationally expensive. In this paper w...

  14. コモンセントロイド配置によるCMOS OTAのCMRR改善効果の評価

    OpenAIRE

    澤本, 岳秀; 桑原, 浩一; 谷本, 洋; 原口, 大; SAWAMOTO, Takehide; KUWAHARA, Koichi; TANIMOTO, Hiroshi; HARAGUCHI, Masaru

    2010-01-01

    Common-mode rejection ratio (CMRR) deviation due to mismatching among MOS transistors in feedforward type OTA has been evaluated for chips fabricated with and without common-centroid layout technique. The mesured common-mode voltage gain (CMVG) data for 10 samples are evaluated by averaged CMVG and its relative variation to input common-mode dc bias point. The results clearly indicate the effectiveness of the common-centroid layout for an OTA in OTA in an 0.15 μm CMOS process to have better C...

  15. Olkiluoto hydrogeochemistry. A 3-D modelling approach for sparce data set

    International Nuclear Information System (INIS)

    Luukkonen, A.; Partamies, S.; Pitkaenen, P.

    2003-07-01

    Olkiluoto at Eurajoki has been selected as a candidate site for final disposal repository for the used nuclear waste produced in Finland. In the long term safety assessment, one of the principal evaluation tools of safe disposal is hydrogeochemistry. For assessment purposes Posiva Oy excavates in the Olkiluoto bedrock an underground research laboratory (ONKALO). The complexity of the groundwater chemistry is characteristic to the Olkiluoto site and causes a demand to examine and visualise these hydrogeochemical features in 3-D together with the structural model. The need to study the hydrogeochemical features is not inevitable only in the stable undisturbed (pre-excavational) conditions but also in the disturbed system caused by the construction activities and open-tunnel conditions of the ONKALO. The present 3-D approach is based on integrating the independently and separately developed structural model and the results from the geochemical mixing calculations of the groundwater samples. For spatial geochemical regression purposes the study area is divided into four primary sectors on the basis of the occurrence of the samples. The geochemical information within the four primary sector are summed up in the four sector centroids that sum-up the depth distributions of the different water types within each primary sector area. The geographic locations of the centroids are used for secondary division of the study area into secondary sectors. With the aid of secondary sectors spatial regressions between the centroids can be calculated and interpolation of water type fractions within the centroid volume becomes possible. Similarly, extrapolations outside the centroid volume are possible as well. The mixing proportions of the five detected water types in an arbitrary point in the modelling volume can be estimated by applying the four centroids and by using lateral linear regression. This study utilises two separate data sets: the older data set and the newer data set. The

  16. Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2015-06-01

    Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.

  17. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    International Nuclear Information System (INIS)

    Blue, Brent Edward

    2005-01-01

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 (micro)m/(delta) z at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 (∼2 x 10 14 cm -3 ), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt

  18. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  19. (E-2-[2-(4-Carboxyphenylethenyl]-8-hydroxyquinolin-1-ium chloride ethanol monosolvate

    Directory of Open Access Journals (Sweden)

    Edwin Weber

    2013-12-01

    Full Text Available In the title compound, C18H14NO3+·Cl−·CH3CH2OH, the dihedral angle formed by the mean planes of the quinolinium and benzene rings is 3.4 (1°, while the carboxy substituent is tilted at an angle of 4.8 (1° with respect to the benzene ring. There is a short N—H...O contact in the cation. In the crystal, due to the planar molecular geometry, two-dimensional aggregates are formed parallel to (221 via C—H...O, C—H...Cl, O—H...Cl and N—H...Cl hydrogen bonds. Interlayer association is accomplished by O—Hethanol...Cl and O—H...Oethanol hydrogen bonds and π–π stacking interactions [centroid–centroid distances vary from 3.6477 (12 to 3.8381 (11 Å]. A supramolecular three-dimensional architecture results from a stacked arrangement of layers comprising the ionic and hydrogen-bonded components.

  20. Beam-dynamics codes used at DARHT

    Energy Technology Data Exchange (ETDEWEB)

    Ekdahl, Jr., Carl August [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-01

    Several beam simulation codes are used to help gain a better understanding of beam dynamics in the DARHT LIAs. The most notable of these fall into the following categories: for beam production – Tricomp Trak orbit tracking code, LSP Particle in cell (PIC) code, for beam transport and acceleration – XTR static envelope and centroid code, LAMDA time-resolved envelope and centroid code, LSP-Slice PIC code, for coasting-beam transport to target – LAMDA time-resolved envelope code, LSP-Slice PIC code. These codes are also being used to inform the design of Scorpius.

  1. A comparison of three speaker-intrinsic vowel formant frequency normalization algorithms for sociophonetics

    DEFF Research Database (Denmark)

    Fabricius, Anne; Watt, Dominic; Johnson, Daniel Ezra

    2009-01-01

    from RP and Aberdeen English (northeast Scotland). We conclude that, for the data examined here, the S-centroid W&F procedures performs at least as well as the two most recognized speaker-intrinsic, vowel-extrinsic, formant-intrinsic normalization methods, Lobanov's (1971) z-score procedure and Nearey......This paper evaluates a speaker-intrinsic vowel formant frequency normalization algorithm initially proposed in Watt & Fabricius (2002). We compare how well this routine, known as the S-centroid procedure, performs as a sociophonetic research tool in three ways: reducing variance in area ratios...

  2. Supporting Information

    Indian Academy of Sciences (India)

    Administrator

    (i,j), deg. ┴ Distance of centroid(i) from ring/metal (j), Å. Distance between the (i,j) ring centroids, Å. R(1) → R(2)i. 6.994. 36.17. 4.050(7). 3.5300. R(1) → R(2)ii. 6.994. 36.17. 4.050(7). 3.5300. R(2) → R(1)i. 6.994. 29.37. 4.050(7). 3.2699. R(2) → R(1)iii. 6.994. 29.37. 4.050(7). 3.2699. R(3) → R(3)iv. 0. 14.14. 3.815(3). 3.6994.

  3. Two methods to estimate the position resolution for straw chambers with strip readout

    International Nuclear Information System (INIS)

    Golutvin, I.A.; Movchan, S.A.; Peshekhonov, V.D.; Preda, T.

    1992-01-01

    The centroid and charge-ratio methods are presented to estimate the position resolution of the straw chambers with strip readout. For the straw chambers of 10 mm in diameter, the highest position resolution was obtained for a strip pitch of 5 mm. With the centroid method and perpendicular X-ray beam, the position resolution was ≅120 μm, for the signal-to-noise ratio of 60-65. The charge-ratio method has demonstrated ≅10% better position resolution at the edges of the strip. 6 refs.; 5 figs

  4. Marginalised Stacked Denoising Autoencoders for Robust Representation of Real-Time Multi-View Action Recognition

    Directory of Open Access Journals (Sweden)

    Feng Gu

    2015-07-01

    Full Text Available Multi-view action recognition has gained a great interest in video surveillance, human computer interaction, and multimedia retrieval, where multiple cameras of different types are deployed to provide a complementary field of views. Fusion of multiple camera views evidently leads to more robust decisions on both tracking multiple targets and analysing complex human activities, especially where there are occlusions. In this paper, we incorporate the marginalised stacked denoising autoencoders (mSDA algorithm to further improve the bag of words (BoWs representation in terms of robustness and usefulness for multi-view action recognition. The resulting representations are fed into three simple fusion strategies as well as a multiple kernel learning algorithm at the classification stage. Based on the internal evaluation, the codebook size of BoWs and the number of layers of mSDA may not significantly affect recognition performance. According to results on three multi-view benchmark datasets, the proposed framework improves recognition performance across all three datasets and outputs record recognition performance, beating the state-of-art algorithms in the literature. It is also capable of performing real-time action recognition at a frame rate ranging from 33 to 45, which could be further improved by using more powerful machines in future applications.

  5. Attenuation (1/Q) estimation in reflection seismic records

    International Nuclear Information System (INIS)

    Raji, Wasiu; Rietbrock, Andreas

    2013-01-01

    Despite its numerous potential applications, the lack of a reliable method for determining attenuation (1/Q) in seismic data is an issue when utilizing attenuation for hydrocarbon exploration. In this paper, a new method for measuring attenuation in reflection seismic data is presented. The inversion process involves two key stages: computation of the centroid frequency for the individual signal using a variable window length and fast Fourier transform; and estimation of the difference in the centroid frequency and travel time for paired incident and transmitted signals. The new method introduces a shape factor and a constant which allows several spectral shapes to be used to represent a real seismic signal without altering the mathematical model. Application of the new method to synthetic data shows that it can provide reliable estimates of Q using any of the spectral shapes commonly assumed for real seismic signals. Tested against two published methods of Q measurement, the new method shows less sensitivity to interference from noise and change of frequency bandwidth. The method is also applied to a 3D data set from the Gullfaks field, North Sea, Norway. The trace length is divided into four intervals: AB, BC, CD, and DE. Results show that interval AB has the lowest 1/Q value, and that interval BC has the highest 1/Q value. The values of 1/Q measured in the CDP stack using the new method are consistent with those measured using the classical spectral ratio method. (paper)

  6. Crystal structure of the salt bis(triethanolamine-κ4N,O,O′,O′′cadmium bis[2-(2-oxo-2,3-dihydro-1,3-benzothiazol-3-ylacetate

    Directory of Open Access Journals (Sweden)

    Jamshid Mengnorovich Ashurov

    2016-04-01

    Full Text Available The reaction of 2-(2-oxo-2,3-dihydro-1,3-benzothiazol-3-ylacetic acid (NBTA and triethanolamine (TEA with Cd(CH3OO2 resulted in the formation of the title salt, [Cd(C6H15NO32](C9H6NO3S2. In its crystal structure, the complex cation [Cd(TEA2]2+ and two independent NBTA− units with essentially similar geometries and conformations are present. In the complex cation, each TEA molecule behaves as an N,O,O′,O′′-tetradentate ligand, giving rise to an eight-coordinate CdII ion with a bicapped trigonal–prismatic configuration. All ethanol groups of each TEA molecule form three five-membered chelate rings around the CdII ion. The Cd—O and Cd—N distances are in the ranges 2.392 (2–2.478 (2 and 2.465 (2–2.475 (3 Å, respectively. O—H...O hydrogen bonds between the TEA hydroxy groups and carboxylate O atoms connect cationic and anionic moieties into chains parallel to [110]. Each NBTA− anion is additionally linked to a symmetry-related anion through π–π stacking interactions between the benzene and thiazoline rings [minimum centroid-to-centroid separation = 3.604 (2 Å]. Together with additional C—H...O interactions, these establish a double-layer polymeric network parallel to (001.

  7. Learning-based stochastic object models for characterizing anatomical variations

    Science.gov (United States)

    Dolly, Steven R.; Lou, Yang; Anastasio, Mark A.; Li, Hua

    2018-03-01

    It is widely known that the optimization of imaging systems based on objective, task-based measures of image quality via computer-simulation requires the use of a stochastic object model (SOM). However, the development of computationally tractable SOMs that can accurately model the statistical variations in human anatomy within a specified ensemble of patients remains a challenging task. Previously reported numerical anatomic models lack the ability to accurately model inter-patient and inter-organ variations in human anatomy among a broad patient population, mainly because they are established on image data corresponding to a few of patients and individual anatomic organs. This may introduce phantom-specific bias into computer-simulation studies, where the study result is heavily dependent on which phantom is used. In certain applications, however, databases of high-quality volumetric images and organ contours are available that can facilitate this SOM development. In this work, a novel and tractable methodology for learning a SOM and generating numerical phantoms from a set of volumetric training images is developed. The proposed methodology learns geometric attribute distributions (GAD) of human anatomic organs from a broad patient population, which characterize both centroid relationships between neighboring organs and anatomic shape similarity of individual organs among patients. By randomly sampling the learned centroid and shape GADs with the constraints of the respective principal attribute variations learned from the training data, an ensemble of stochastic objects can be created. The randomness in organ shape and position reflects the learned variability of human anatomy. To demonstrate the methodology, a SOM of an adult male pelvis is computed and examples of corresponding numerical phantoms are created.

  8. Automated computer analysis of plasma-streak traces from SCYLLAC

    International Nuclear Information System (INIS)

    Whitman, R.L.; Jahoda, F.C.; Kruger, R.P.

    1977-01-01

    An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of sixteen plasma traces has been processed using this technique

  9. Automated computer analysis of plasma-streak traces from SCYLLAC

    International Nuclear Information System (INIS)

    Whiteman, R.L.; Jahoda, F.C.; Kruger, R.P.

    1977-11-01

    An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of the plasma traces has been processed with this technique

  10. Spatial pattern recognition of seismic events in South West Colombia

    Science.gov (United States)

    Benítez, Hernán D.; Flórez, Juan F.; Duque, Diana P.; Benavides, Alberto; Lucía Baquero, Olga; Quintero, Jiber

    2013-09-01

    Recognition of seismogenic zones in geographical regions supports seismic hazard studies. This recognition is usually based on visual, qualitative and subjective analysis of data. Spatial pattern recognition provides a well founded means to obtain relevant information from large amounts of data. The purpose of this work is to identify and classify spatial patterns in instrumental data of the South West Colombian seismic database. In this research, clustering tendency analysis validates whether seismic database possesses a clustering structure. A non-supervised fuzzy clustering algorithm creates groups of seismic events. Given the sensitivity of fuzzy clustering algorithms to centroid initial positions, we proposed a methodology to initialize centroids that generates stable partitions with respect to centroid initialization. As a result of this work, a public software tool provides the user with the routines developed for clustering methodology. The analysis of the seismogenic zones obtained reveals meaningful spatial patterns in South-West Colombia. The clustering analysis provides a quantitative location and dispersion of seismogenic zones that facilitates seismological interpretations of seismic activities in South West Colombia.

  11. Reducing Earth Topography Resolution for SMAP Mission Ground Tracks Using K-Means Clustering

    Science.gov (United States)

    Rizvi, Farheen

    2013-01-01

    The K-means clustering algorithm is used to reduce Earth topography resolution for the SMAP mission ground tracks. As SMAP propagates in orbit, knowledge of the radar antenna footprints on Earth is required for the antenna misalignment calibration. Each antenna footprint contains a latitude and longitude location pair on the Earth surface. There are 400 pairs in one data set for the calibration model. It is computationally expensive to calculate corresponding Earth elevation for these data pairs. Thus, the antenna footprint resolution is reduced. Similar topographical data pairs are grouped together with the K-means clustering algorithm. The resolution is reduced to the mean of each topographical cluster called the cluster centroid. The corresponding Earth elevation for each cluster centroid is assigned to the entire group. Results show that 400 data points are reduced to 60 while still maintaining algorithm performance and computational efficiency. In this work, sensitivity analysis is also performed to show a trade-off between algorithm performance versus computational efficiency as the number of cluster centroids and algorithm iterations are increased.

  12. Location of trapped charge in aluminum-implanted SiO2

    International Nuclear Information System (INIS)

    DiMaria, D.J.; Young, D.R.; Hunter, W.R.; Serrano, C.M.

    1978-01-01

    The position of the centroid of electrons trapped on sites resulting from aluminum implantation into SiO 2 is measured by using the photo I-V technique for energies from 15 to 40 keV, oxide thicknesses from 49 to 140 nm, and post-implant annealing temperature from 600 to 1050 0 C in N 2 for 30 min. The centroid of the trapped electrons is found to be identical to that of the implanted aluminum from SIMS measurements, regardless of annealing temperature from 600 to 1050 0 C, and located closer (by less than 9 nm) to the Al--SiO 2 interface than predicted from the Lindhard-Scharff-Schott (LSS) calculations of Gibbons, Johnson, and Mylroie. Comparison of centroids determined from photo I-V and SIMS measurements as a function of SiO 2 thickness also implies that the distributions of the ions and negative trapped charge are the same. The trapping behavior of these sites is discussed in the accompanying paper by Young et al

  13. Perpendicularity misjudgments caused by contextual stimulus elements.

    Science.gov (United States)

    Bulatov, Aleksandr; Bulatova, Natalija; Surkys, Tadas

    2012-10-15

    It has been demonstrated in previous studies that the illusions of extent of the Brentano type can be explained by the perceptual positional shifts of the stimulus terminators in direction of the centers-of-masses (centroids) of adjacent contextual flanks [Bulatov, A. et al. (2011). Contextual flanks' tilting and magnitude of illusion of extent. Vision Research, 51(1), 58-64]. In the present study, the applicability of the centroid approach to explain the right-angle misjudgments was tested psychophysically using stimuli composed of three small disks (dots) forming an imaginary rectangular triangle. Stimuli comprised the Müller-Lyer wings or line segments (bars) as the contextual distracters rotated around the vertices of the triangle, and changes in the magnitude of the illusion of perpendicularity were measured in a set of experiments. A good resemblance between the experimental data and theoretical predictions obtained strongly supports the suggestion regarding the common "centroid" origin of the illusions of extent of the Brentano type and misperception of the perpendicularity investigated. 2012 Elsevier Ltd. All rights reserved

  14. An evaluation of centrality measures used in cluster analysis

    Science.gov (United States)

    Engström, Christopher; Silvestrov, Sergei

    2014-12-01

    Clustering of data into groups of similar objects plays an important part when analysing many types of data, especially when the datasets are large as they often are in for example bioinformatics, social networks and computational linguistics. Many clustering algorithms such as K-means and some types of hierarchical clustering need a number of centroids representing the 'center' of the clusters. The choice of centroids for the initial clusters often plays an important role in the quality of the clusters. Since a data point with a high centrality supposedly lies close to the 'center' of some cluster, this can be used to assign centroids rather than through some other method such as picking them at random. Some work have been done to evaluate the use of centrality measures such as degree, betweenness and eigenvector centrality in clustering algorithms. The aim of this article is to compare and evaluate the usefulness of a number of common centrality measures such as the above mentioned and others such as PageRank and related measures.

  15. Poly[octa-μ-aqua-tetraaquabis(μ-5-sulfonatobenzene-1,3-dicarboxylatocobalt(IItetrasodium

    Directory of Open Access Journals (Sweden)

    Bing-Yu Zhang

    2009-04-01

    Full Text Available The title compound, [CoNa4(C8H3O7S2(H2O12]n, is a three-dimensional coordination polymer bridged by sulfoisophthalate trianions and water molecules. The CoII atom, located on an inversion centre, is coordinated by two carboxylate groups of the sulfoisophthalate trianions and by four water molecules in a distorted CoO6 octahedral geometry. Two independent NaI atoms also have a distorted octahedral coordination geometry formed by water, carboxylate O and sulfonate O atoms. An extensive O—H...O and C—H...O hydrogen-bonding network is present in the crystal structure, as well as weak π-π stacking [centroid–centroid distance = 3.9553 (11 Å].

  16. (2E-3-(6-Chloro-2-methoxyquinolin-3-yl-1-(2-methyl-4-phenylquinolin-3-ylprop-2-en-1-one acetone monosolvate

    Directory of Open Access Journals (Sweden)

    Edward R. T. Tiekink

    2013-08-01

    Full Text Available In the title solvate, C29H21ClN2O2·C3H6O, a prop-2-en-1-one bridge links two quinolinyl residues; the latter are almost perpendicular [dihedral angle = 78.27 (6°]. The dihedral angle between the quinonyl ring system and its pendant phenyl group is 59.78 (8°. A small twist in the bridging prop-2-en-1-one group is noted [O=C—C=C torsion angle = −10.6 (3°]. In the crystal, a three-dimensional architecture arises as a result of C—H...O and π–π stacking [centroid–centroid distances = 3.5504 (12–3.6623 (12 Å].

  17. Poly[μ2-aqua-aqua-μ4-pyridine-2,4-dicarboxylato-strontium

    Directory of Open Access Journals (Sweden)

    Zohreh Derikvand

    2009-08-01

    Full Text Available In the title polymeric complex, [Sr(C7H3NO4(H2O2]n, the SrII atom is eight-coordinated by four O atoms and one N atom of four pyridine-2,4-dicarboxylate (py-2,4-dc ligands and three O atoms of three coordinated water molecules in a dodecahedral geometry. These units are connected via the carboxylate O atoms and water molecules, building polymeric layers parallel to (100. In the crystal structure, non-covalent interactions consisting of O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.862 (17 and 3.749 (17 Å] connect the various components, forming a three-dimensional structure.

  18. catena-Poly[{μ3-4,4′,6,6′-tetrabromo-2,2′-[butane-1,4-diylbis(nitrilomethanylylidene]diphenolato}{μ2-4,4′,6,6′-tetrabromo-2,2′-[butane-1,4-diylbis(nitrilomethanylylidene]diphenolato}dicopper(II

    Directory of Open Access Journals (Sweden)

    Hadi Kargar

    2012-07-01

    Full Text Available The asymmetric unit of the title coordination polymer consists of a dinuclear neutral complex molecule of formula [Cu2(C18H14Br4N2O22]n. One of the CuII ions is coordinated in a distorted square-planar geometry, whereas the other is coordinated in a distorted square-pyramidal geometry, the long apical Cu—O bond [2.885 (4 Å] of the square-pyramidal coordination being provided by a symmetry-related O atom creating a one-dimensional polymer along [010]. π–π stacking interactions [centroid–centroid distance = 3.783 (4 Å] and short interchain Br...Br interactions [3.6142 (12–3.6797 (12 Å] are observed.

  19. 1-Benzylimidazolium hexafluorophosphate–1-benzylimidazole (1/1

    Directory of Open Access Journals (Sweden)

    Qing-Xiang Liu

    2008-02-01

    Full Text Available In the title compound, C10H11N2+·PF6−·C10H10N2, the H atom involved in protonation is disordered equally between the cation and the neutral molecule. The dihedral angle between the phenyl and imidazole rings is 82.6 (2°. In the crystal structure, there are head-to-tail π–π stacking interactions between imidazole rings; the interplanar separation is 3.295 (1 Å and the centroid–centroid separation is 3.448 (3 Å. In the centrosymmetric anion, two F atoms are disordered over two positions; the refined site-occupancy factors are 0.855 (11 and 0.145 (11.

  20. Redetermination of 3,5-dimethylphenol

    Directory of Open Access Journals (Sweden)

    Richard Betz

    2011-05-01

    Full Text Available The previous structure determination [Gillier-Pandraud et al. (1972. C. R. Acad. Sci. Ser. C, 275, 1495] of the title compound, C8H10O, did not report atomic coordinates. There are two molecules in the asymmetric unit, A and B, which both show approximate non-crystallographic Cs symmetry. The intracyclic C—C—C angles cover the range 118.74 (12–121.76 (13°. In the crystal, molecules are linked by O—H...O hydrogen bonds, generating [001] C22(4 chains such that molecules A and B alternate. There is no aromatic π–π stacking in the crystal as the shortest centroid–centroid distance is greater than 4.74 Å.

  1. [2,9-Bis(3,5-dimethyl-1H-pyrazol-1-yl-κN2-1,10-phenanthroline-κ2N,N′]bis(thiocyanato-κNcadmium(II

    Directory of Open Access Journals (Sweden)

    Yan Hui Chi

    2011-01-01

    Full Text Available In the title complex, [Cd(NCS2(C22H20N6], the CdII ion is in a CdN6 coordination geometry which is intermediate between octahedral and trigonal–prismatic. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline system are 15.74 (15 and 16.30 (13°. In the crystal, there is a π–π stacking interaction involving two symmetry-related pyrazole rings, with a centroid–centroid distance of 3.664 (3 Å. In addition, there is a relatively short intermolecular contact between C atoms [C...C = 3.399 (6 Å] involving symmetry-related pyridine rings along the a axis.

  2. 7-Chloro-4-oxo-4H-chromene-3-carbaldehyde

    Directory of Open Access Journals (Sweden)

    Yoshinobu Ishikawa

    2014-08-01

    Full Text Available In the title compound, C10H5ClO3, a chlorinated 3-formylchromone derivative, all atoms are essentially coplanar (r.m.s. deviation = 0.0592 Å for all non-H atoms, with the largest deviation from the least-squares plane [0.1792 (19 Å] being for the chromone-ring carbonyl O atom. In the crystal, molecules are linked through C—H...O hydrogen bonds to form tetrads, which are assembled by stacking interactions [centroid–centroid distance between the pyran rings = 3.823 (3 Å] and van der Waals contacts between the Cl atoms [Cl...Cl = 3.4483 (16 Å and C—Cl...Cl = 171.73 (7°] into a three-dimensional architecture.

  3. 3-[2-(1,3-Benzothiazol-2-ylsulfanylethyl]-1,3-oxazolidin-2-one

    Directory of Open Access Journals (Sweden)

    Yong-Hong Wen

    2010-10-01

    Full Text Available The title compound, C12H12N2S2O2, consists of a benzothiazole group and a oxazolidin-1-one linked via a flexible ethane-1,2-diyl spacer. The benzothiazole group and the oxazolidine ring are each almost planar [with maximum deviations of 0.007 (2 and 0.044 (3 Å, respectively] and make a dihedral angle of 9.35 (10°. In the crystal structure, adjacent molecules were connected through C—H...O and C—H...N hydrogen bonds, and further extended into a three-dimensional network structure through intermolecular aromatic π–π stacking interactions in which the centroid–centroid distance is 3.590 (1 Å.

  4. μ-(2,6-Bis{[3-(dimethylaminopropyl]iminomethyl}-4-methylphenolato-μ-hydroxido-bis[(thiocyanato-κNcopper(II

    Directory of Open Access Journals (Sweden)

    M. G. Meera

    2013-10-01

    Full Text Available In the title compound, [Cu2(C19H31N4O(OH(NCS2], the molecular structure of the dinuclear complex reveals two pentacoordinated CuII ions, which are bridged by the phenolate O atom of the ligand and by an exogenous hydroxide ion. The bridging atoms occupy equatorial positions in the coordination sphere of the metal atoms and complete the equatorial coordination planes with two ligand N atoms, the apical positions being occupied by thiocyanate N atoms. The crystal structure also features π–π stacking interactions involving the benzene rings with a centroid–centroid distance of 3.764 (4Å. The crystal studied was a non-merohedral twin, with a refined BASF value of 0.203 (2

  5. (E-1-(2-Bromophenyl-3-(2,5-dimethoxyphenylprop-2-en-1-one

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    Jerry P. Jasinski

    2010-08-01

    Full Text Available The title compound, C17H15BrO3, is a chalcone with the 2-bromophenyl and 2,5-dimethoxyphenyl rings bonded at opposite ends of a propene group. The dihedral angle between the mean planes of the ortho-bromo and ortho,meta-dimethoxy-substituted benzene rings is 77.3 (1°. The dihedral angles between the mean plane of the prop-2-ene-1-one group and the mean planes of the 2-bromophenyl and 2,5-dimethoxyphenyl rings are 58.6 (1 and 30.7 (4°, respectively. Weak C—H...O, C—H...Br and π–π stacking intermolecular interactions [centroid–centroid distance = 3.650 (2 Å] are present in the structure.

  6. Crystal structure of the borabenzene–2,6-lutidine adduct

    Directory of Open Access Journals (Sweden)

    Lauri Kivijärvi

    2015-12-01

    Full Text Available In the title compound, C12H14BN, the complete molecule is generated by a crystallographic twofold axis, with two C atoms, the B atom and the N atom lying on the rotation axis. The dihedral angle between the borabenzene and pyridine rings is 81.20 (6°. As well as dative electron donation from the N atom to the B atom [B—N = 1.5659 (18 Å], the methyl substituents on the lutidine ring shield the B atom, which further stabilizes the molecule. In the crystal, weak aromatic π–π stacking between the pyridine rings [centroid–centroid separation = 3.6268 (9 Å] is observed, which generates [001] columns of molecules.

  7. 2-(5-Fluoro-3-isopropylsulfanyl-1-benzofuran-2-ylacetic acid

    Directory of Open Access Journals (Sweden)

    Pil Ja Seo

    2011-11-01

    Full Text Available The title compound, C13H13FO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-fluoro-3-isopropylsulfanyl-1-benzofuran-2-ylacetate. In the crystal, the carboxy groups are involved in intermolecular O—H...O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the b axis by a slipped π–π interaction between the furan and benzene rings of neighbouring molecules [centroid–centroid distance = 3.727 (2 Å, interplanar distance = 3.465 (2 Å and slippage = 1.373 (2 Å]. The crystal structure also exhibits a short S...O contact [S...O = 3.219 (2 Å].

  8. 2-(1H-Benzimidazol-2-ylphenol

    Directory of Open Access Journals (Sweden)

    S. M. Prakash

    2014-02-01

    Full Text Available The title molecule, C13H10N2O, is essentially planar, the maximum deviation from the plane of the non-H atoms being 0.016 (2 Å. The imidazole ring makes a dihedral angle of 0.37 (13° with the attached benzene ring. An intramolecular O—H...N hydrogen bond generates an S(6 ring motif. In the crystal, molecules are linked through N—H...O hydrogen bonds, forming chains propagating in [001]. The crystal packing also features four π–π stacking interactions involving the imidazole ring, fused benzene ring and attached benzene ring system [centroid–centroid distances = 3.6106 (17, 3.6108 (17, 3.6666 (17 and 3.6668 (17 Å].

  9. (3Z-5-Chloro-3-(hydroxyiminoindolin-2-one

    Directory of Open Access Journals (Sweden)

    Bianca Barreto Martins

    2016-10-01

    Full Text Available In the title compound, C8H5ClN2O2 (common name: 5-chloroisatin 3-oxime, the molecular structure deviates slightly from the ideal planarity, with a maximum deviation of 0.0478 (8 Å for the non-H atoms. In the crystal, molecules are linked by N—H...O interactions, building centrosymmetric dimers with graph-set motif R22(8. Additionally, the molecules are connected by pairs of O—H...O interactions into chains along [100] with a C(6 motif. The hydrogen-bonded dimers and chains build a two-dimensional network parallel to (100. The packing also features π–π stacking interactions between benzene rings [centroid–centroid distance = 3.748 (2 Å].

  10. Tris(2,2′-bipyridine-κ2 N,N′)cobalt(III) bis­[bis­(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)cobaltate(III)] perchlorate dimethyl­formamide hemisolvate 1.3-hydrate

    Science.gov (United States)

    Golenya, Irina A.; Boyko, Alexander N.; Kotova, Natalia V.; Haukka, Matti; Iskenderov, Turganbay S.

    2012-01-01

    In the title compound, [Co(C10H8N2)3][Co(C7H3NO4)2]2(ClO4)·0.5C3H7NO·1.3H2O, the CoIII atom in the complex cation is pseudoocta­hedrally coordinated by six N atoms of three chelating bipyridine ligands. The CoIII atom in the complex anion is coordinated by two pyridine N atoms and four carboxyl­ate O atoms of two doubly deprotonated pyridine-2,6-dicarboxyl­ate ligands in a distorted octa­hedral geometry. One dimethyl­formamide solvent mol­ecule and two water mol­ecules are half-occupied and one water mol­ecule is 0.3-occupied. O—H⋯O hydrogen bonds link the water mol­ecules, the perchlorate anions and the complex anions. π–π inter­actions between the pyridine rings of the complex anions are also observed [centroid–centroid distance = 3.804 (3) Å]. PMID:23125573

  11. 1-Benzyl-5-bromoindoline-2,3-dione

    Directory of Open Access Journals (Sweden)

    Yassine Kharbach

    2016-04-01

    Full Text Available In the title compound, C15H10BrNO2, the indoline ring system, the two ketone O atoms and the Br atom lie in a common plane, with the largest deviation from the mean plane being 0.073 (1 Å for the Br atom. The fused-ring system is nearly perpendicular to the benzyl ring, as indicated by the dihedral angle between them of 74.58 (10°. In the crystal, molecules are linked by weak C—H...O hydrogen bonds and by π–π interactions [inter-centroid distance = 3.625 (2 Å], forming a two-dimensional structure.

  12. Consolidity: Stack-based systems change pathway theory elaborated

    Directory of Open Access Journals (Sweden)

    Hassen Taher Dorrah

    2014-06-01

    , programming and hardware representations of each stack layering type to serve in reducing tremendously any repetitive research efforts in future handling of similar or analogous problems of real life systems. Finally, a new global inter-related stack-based configuration in multi-stacking networks is proposed incorporating conceptually the mutual stack-based changes balancing process through assumed ideal case of lossless bi-directional transfer piping systems.

  13. How processing digital elevation models can affect simulated water budgets

    Science.gov (United States)

    Kuniansky, E.L.; Lowery, M.A.; Campbell, B.G.

    2009-01-01

    For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation of the water table used in model cells is estimated via a two-step process. First, a regression equation is developed using existing land and water table elevations from wells in the area. This equation is then used to predict the water table surface for each model cell using land surface elevation available from digital elevation models (DEM). Two methods of processing DEM for estimating the land surface for each cell are commonly used (value nearest the cell centroid or mean value in the cell). This article demonstrates how these two methods of DEM processing can affect the simulated water budget. For the example presented, approximately 20% more total flow through the aquifer system is simulated if the centroid value rather than the mean value is used. This is due to the one-third greater average ground water gradients associated with the centroid value than the mean value. The results will vary depending on the particular model area topography and cell size. The use of the mean DEM value in each model cell will result in a more conservative water budget and is more appropriate because the model cell water table value should be representative of the entire cell area, not the centroid of the model cell.

  14. Improving experimental phases for strong reflections prior to density modification

    International Nuclear Information System (INIS)

    Uervirojnangkoorn, Monarin; Hilgenfeld, Rolf; Terwilliger, Thomas C.; Read, Randy J.

    2013-01-01

    A genetic algorithm has been developed to optimize the phases of the strongest reflections in SIR/SAD data. This is shown to facilitate density modification and model building in several test cases. Experimental phasing of diffraction data from macromolecular crystals involves deriving phase probability distributions. These distributions are often bimodal, making their weighted average, the centroid phase, improbable, so that electron-density maps computed using centroid phases are often non-interpretable. Density modification brings in information about the characteristics of electron density in protein crystals. In successful cases, this allows a choice between the modes in the phase probability distributions, and the maps can cross the borderline between non-interpretable and interpretable. Based on the suggestions by Vekhter [Vekhter (2005 ▶), Acta Cryst. D61, 899–902], the impact of identifying optimized phases for a small number of strong reflections prior to the density-modification process was investigated while using the centroid phase as a starting point for the remaining reflections. A genetic algorithm was developed that optimizes the quality of such phases using the skewness of the density map as a target function. Phases optimized in this way are then used in density modification. In most of the tests, the resulting maps were of higher quality than maps generated from the original centroid phases. In one of the test cases, the new method sufficiently improved a marginal set of experimental SAD phases to enable successful map interpretation. A computer program, SISA, has been developed to apply this method for phase improvement in macromolecular crystallography

  15. Measuring the Alfvénic nature of the interstellar medium: Velocity anisotropy revisited

    International Nuclear Information System (INIS)

    Burkhart, Blakesley; Lazarian, A.; Leão, I. C.; De Medeiros, J. R.; Esquivel, A.

    2014-01-01

    The dynamics of the interstellar medium (ISM) are strongly affected by turbulence, which shows increased anisotropy in the presence of a magnetic field. We expand upon the Esquivel and Lazarian method to estimate the Alfvén Mach number using the structure function anisotropy in velocity centroid data from Position-Position-Velocity maps. We utilize three-dimensional magnetohydrodynamic simulations of fully developed turbulence, with a large range of sonic and Alfvénic Mach numbers, to produce synthetic observations of velocity centroids with observational characteristics such as thermal broadening, cloud boundaries, noise, and radiative transfer effects of carbon monoxide. In addition, we investigate how the resulting anisotropy-Alfvén Mach number dependency found in Esquivel and Lazarian might change when taking the second moment of the Position-Position-Velocity cube or when using different expressions to calculate the velocity centroids. We find that the degree of anisotropy is related primarily to the magnetic field strength (i.e., Alfvén Mach number) and the line-of-sight orientation, with a secondary effect on sonic Mach number. If the line of sight is parallel to up to ≈45 deg off of the mean field direction, the velocity centroid anisotropy is not prominent enough to distinguish different Alfvénic regimes. The observed anisotropy is not strongly affected by including radiative transfer, although future studies should include additional tests for opacity effects. These results open up the possibility of studying the magnetic nature of the ISM using statistical methods in addition to existing observational techniques.

  16. Determinación del centro de esfuerzo en un troquel de corte utilizando un programa CAD

    OpenAIRE

    BALDI DE COSTA, CLARA

    2006-01-01

    Se discute la importancia de la correcta ubicación del centro de esfuerzo en un troquel de corte para minimizar las cargas laterales sobre los , elementos de guía. Se describe el proceso matemático para determinar el centro de esfuerzo a través del cálculo del centroide de una curva, y sucesivamente se proporciona un método de aproximación que utiliza la capacidad de AutoCAD de calcular el centroide de una región plana bidimensional. The importance of a correct positioning of the force cen...

  17. Impact of Optics on CSR-Related Emittance Growth in Bunch Compressor Chicanes

    CERN Document Server

    Limberg, Torsten

    2005-01-01

    The dependence of emittance growth due to Coherent Synchrotron Radiation (CSR) in bunch compressor chicanes on optics has been noticed and empirically studied in the past. We revisit the subject, suggesting a model to explain slice emittance growth dependence on chicane optics. A simplified model to calculate projected emittance growth when it is mainly caused by transverse slice centroid offsets is presented. It is then used to find optimal compensation of centroid kicks in the single chicanes of a two-stage compression system by adjusting the phase advance of the transport in between and the ration of the compression factors.

  18. Near-infrared mapping of ARP 299 (IC 694-NGC 3690) - colliding galaxies unveiled

    International Nuclear Information System (INIS)

    Telesco, C.M.; Decher, R.; Gatley, I.; Edinburgh Royal Observatory, England)

    1985-01-01

    Near-infrared maps and multicolor photometry of the interacting galaxies IC 694 and NGC 3690 which form Arp 299 (= Markarian 171) are presented. These data reveal for the first time the distribution of nuclei and old red stars in a cataclysmically interacting system. The nuclei are considerably offset from the visual centroids of the galaxies but not from the mass centroids. The near-infrared colors of the most active regions are strongly affected by extinction, emission form hot dust, and bremsstrahlung. Near-infrared emission is also identified with secondary regions of star formation, probably resulting from the galaxies interaction. 24 references

  19. A new efficient mixture screening design for optimization of media.

    Science.gov (United States)

    Rispoli, Fred; Shah, Vishal

    2009-01-01

    Screening ingredients for the optimization of media is an important first step to reduce the many potential ingredients down to the vital few components. In this study, we propose a new method of screening for mixture experiments called the centroid screening design. Comparison of the proposed design with Plackett-Burman, fractional factorial, simplex lattice design, and modified mixture design shows that the centroid screening design is the most efficient of all the designs in terms of the small number of experimental runs needed and for detecting high-order interaction among ingredients. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

  20. Shallow conduit system at Kilauea Volcano, Hawaii, revealed by seismic signals associated with degassing bursts

    Science.gov (United States)

    Chouet, Bernard; Dawson, Phillip

    2011-01-01

    Eruptive activity at the summit of Kilauea Volcano, Hawaii, beginning in March, 2008 and continuing to the present time is characterized by episodic explosive bursts of gas and ash from a vent within Halemaumau Pit Crater. These bursts are accompanied by seismic signals that are well recorded by a broadband network deployed in the summit caldera. We investigate in detail the dimensions and oscillation modes of the source of a representative burst in the 1−10 s band. An extended source is realized by a set of point sources distributed on a grid surrounding the source centroid, where the centroid position and source geometry are fixed from previous modeling of very-long-period (VLP) data in the 10–50 s band. The source time histories of all point sources are obtained simultaneously through waveform inversion carried out in the frequency domain. Short-scale noisy fluctuations of the source time histories between adjacent sources are suppressed with a smoothing constraint, whose strength is determined through a minimization of the Akaike Bayesian Information Criterion (ABIC). Waveform inversions carried out for homogeneous and heterogeneous velocity structures both image a dominant source component in the form of an east trending dike with dimensions of 2.9 × 2.9 km. The dike extends ∼2 km west and ∼0.9 km east of the VLP centroid and spans the depth range 0.2–3.1 km. The source model for a homogeneous velocity structure suggests the dike is hinged at the source centroid where it bends from a strike E 27°N with northern dip of 85° west of the centroid, to a strike E 7°N with northern dip of 80° east of the centroid. The oscillating behavior of the dike is dominated by simple harmonic modes with frequencies ∼0.2 Hz and ∼0.5 Hz, representing the fundamental mode ν11 and first degenerate mode ν12 = ν21 of the dike. Although not strongly supported by data in the 1–10 s band, a north striking dike segment is required for enhanced compatibility with

  1. Hubbard-Stratonovich-like Transformations for Few-Body Inter-actions

    Directory of Open Access Journals (Sweden)

    Körber Christopher

    2018-01-01

    Full Text Available Through the development of many-body methodology and algorithms, it has become possible to describe quantum systems composed of a large number of particles with great accuracy. Essential to all these methods is the application of auxiliary fields via the Hubbard-Stratonovich transformation. This transformation effectively reduces two-body interactions to interactions of one particle with the auxiliary field, thereby improving the computational scaling of the respective algorithms. The relevance of collective phenomena and interactions grows with the number of particles. For many theories, e.g. Chiral Perturbation Theory, the inclusion of three-body forces has become essential in order to further increase the accuracy on the many-body level. In this proceeding, the an-alytical framework for establishing a Hubbard-Stratonovich-like transformation, which allows for the systematic and controlled inclusion of contact three-and more-body inter-actions, is presented.

  2. Occurrence and stability of lone pair–π stacking interactions between ribose and nucleobases in functional RNAs

    KAUST Repository

    Chawla, Mohit; Chermak, Edrisse; Zhang, Qingyun; Bujnicki, Janusz M.; Oliva, Romina; Cavallo, Luigi

    2017-01-01

    The specific folding pattern and function of RNA molecules lies in various weak interactions, in addition to the strong base-base pairing and stacking. One of these relatively weak interactions, characterized by the stacking of the O4′ atom of a ribose on top of the heterocycle ring of a nucleobase, has been known to occur but has largely been ignored in the description of RNA structures. We identified 2015 ribose–base stacking interactions in a high-resolution set of non-redundant RNA crystal structures. They are widespread in structured RNA molecules and are located in structural motifs other than regular stems. Over 50% of them involve an adenine, as we found ribose-adenine contacts to be recurring elements in A-minor motifs. Fewer than 50% of the interactions involve a ribose and a base of neighboring residues, while approximately 30% of them involve a ribose and a nucleobase at least four residues apart. Some of them establish inter-domain or inter-molecular contacts and often implicate functionally relevant nucleotides. In vacuo ribose-nucleobase stacking interaction energies were calculated by quantum mechanics methods. Finally, we found that lone pair–π stacking interactions also occur between ribose and aromatic amino acids in RNA–protein complexes.

  3. Occurrence and stability of lone pair–π stacking interactions between ribose and nucleobases in functional RNAs

    KAUST Repository

    Chawla, Mohit

    2017-08-18

    The specific folding pattern and function of RNA molecules lies in various weak interactions, in addition to the strong base-base pairing and stacking. One of these relatively weak interactions, characterized by the stacking of the O4′ atom of a ribose on top of the heterocycle ring of a nucleobase, has been known to occur but has largely been ignored in the description of RNA structures. We identified 2015 ribose–base stacking interactions in a high-resolution set of non-redundant RNA crystal structures. They are widespread in structured RNA molecules and are located in structural motifs other than regular stems. Over 50% of them involve an adenine, as we found ribose-adenine contacts to be recurring elements in A-minor motifs. Fewer than 50% of the interactions involve a ribose and a base of neighboring residues, while approximately 30% of them involve a ribose and a nucleobase at least four residues apart. Some of them establish inter-domain or inter-molecular contacts and often implicate functionally relevant nucleotides. In vacuo ribose-nucleobase stacking interaction energies were calculated by quantum mechanics methods. Finally, we found that lone pair–π stacking interactions also occur between ribose and aromatic amino acids in RNA–protein complexes.

  4. Thermodynamic and critical properties of an antiferromagnetically stacked triangular Ising antiferromagnet in a field

    Science.gov (United States)

    Žukovič, M.; Borovský, M.; Bobák, A.

    2018-05-01

    We study a stacked triangular lattice Ising model with both intra- and inter-plane antiferromagnetic interactions in a field, by Monte Carlo simulation. We find only one phase transition from a paramagnetic to a partially disordered phase, which is of second order and 3D XY universality class. At low temperatures we identify two highly degenerate phases: at smaller (larger) fields the system shows long-range ordering in the stacking direction (within planes) but not in the planes (stacking direction). Nevertheless, crossovers to these phases do not have a character of conventional phase transitions but rather linear-chain-like excitations.

  5. Bayesian ISOLA: new tool for automated centroid moment tensor inversion

    Czech Academy of Sciences Publication Activity Database

    Vackář, J.; Burjánek, Jan; Gallovič, F.; Zahradník, J.; Clinton, J.

    2017-01-01

    Roč. 210, č. 2 (2017), s. 693-705 ISSN 0956-540X Institutional support: RVO:67985530 Keywords : inverse theory * waveform inversion * computational seismology * earthquake source observations * seismic noise Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Volcanology Impact factor: 2.414, year: 2016

  6. Distal turbidite fan/lobe succession of the Late Oligocene Zuberec Fm. - architecture and hierarchy (Central Western Carpathians, Orava-Podhale basin)

    Science.gov (United States)

    Starek, Dušan; Fuksi, Tomáš

    2017-08-01

    A part of the Upper Oligocene sand-rich turbidite systems of the Central Carpathian Basin is represented by the Zuberec Formation. Sand/mud-mixed deposits of this formation are well exposed in the northern part of the basin, allowing us to interpret the turbidite succession as terminal lobe deposits of a submarine fan. This interpretation is based on the discrimination of three facies associations that are comparable to different components of distributive lobe deposits in deep-water fan systems. They correspond to the lobe off-axis, lobe fringe and lobe distal fringe depositional subenvironments, respectively. The inferences about the depositional paleoenvironment based on sedimentological observations are verified by statistical analyses. The bed-thickness frequency distributions and vertical organization of the facies associations show cyclic trends at different hierarchical levels that enable us to reconstruct architectural elements of a turbidite fan. First, small-scale trends correspond with shift in the lobe element centroid between successive elements. Differences in the distribution and frequency of sandstone bed thicknesses as well as differences in the shape of bed-thickness frequency distributions between individual facies associations reflect a gradual fining and thinning in a down-dip direction. Second, meso-scale trends are identified within lobes and they generally correspond to the significant periodicity identified by the time series analysis of the bed thicknesses. The meso-scale trends demonstrate shifts in the position of the lobe centroid within the lobe system. Both types of trends have a character of a compensational stacking pattern and could be linked to autogenic processes. Third, a largescale trend documented by generally thickening-upward stacking pattern of beds, accompanied by a general increase of the sandstones/mudstones ratio and by a gradual change of percentage of individual facies, could be comparable to lobe-system scale. This

  7. Distal turbidite fan/lobe succession of the Late Oligocene Zuberec Fm. – architecture and hierarchy (Central Western Carpathians, Orava–Podhale basin

    Directory of Open Access Journals (Sweden)

    Starek Dušan

    2017-08-01

    Full Text Available A part of the Upper Oligocene sand-rich turbidite systems of the Central Carpathian Basin is represented by the Zuberec Formation. Sand/mud-mixed deposits of this formation are well exposed in the northern part of the basin, allowing us to interpret the turbidite succession as terminal lobe deposits of a submarine fan. This interpretation is based on the discrimination of three facies associations that are comparable to different components of distributive lobe deposits in deep-water fan systems. They correspond to the lobe off-axis, lobe fringe and lobe distal fringe depositional subenvironments, respectively. The inferences about the depositional paleoenvironment based on sedimentological observations are verified by statistical analyses. The bed-thickness frequency distributions and vertical organization of the facies associations show cyclic trends at different hierarchical levels that enable us to reconstruct architectural elements of a turbidite fan. First, small-scale trends correspond with shift in the lobe element centroid between successive elements. Differences in the distribution and frequency of sandstone bed thicknesses as well as differences in the shape of bed-thickness frequency distributions between individual facies associations reflect a gradual fining and thinning in a down-dip direction. Second, meso-scale trends are identified within lobes and they generally correspond to the significant periodicity identified by the time series analysis of the bed thicknesses. The meso-scale trends demonstrate shifts in the position of the lobe centroid within the lobe system. Both types of trends have a character of a compensational stacking pattern and could be linked to autogenic processes. Third, a largescale trend documented by generally thickening-upward stacking pattern of beds, accompanied by a general increase of the sandstones/mudstones ratio and by a gradual change of percentage of individual facies, could be comparable to lobe

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

    International Nuclear Information System (INIS)

    Bittner, Nathan; Butler, Wayne M.; Reed, Joshua L.; Murray, Brian C.; Kurko, Brian S.; Wallner, Kent E.; Merrick, Gregory S.

    2010-01-01

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

  9. Connecting optical and X-ray tracers of galaxy cluster relaxation

    Science.gov (United States)

    Roberts, Ian D.; Parker, Laura C.; Hlavacek-Larrondo, Julie

    2018-04-01

    Substantial effort has been devoted in determining the ideal proxy for quantifying the morphology of the hot intracluster medium in clusters of galaxies. These proxies, based on X-ray emission, typically require expensive, high-quality X-ray observations making them difficult to apply to large surveys of groups and clusters. Here, we compare optical relaxation proxies with X-ray asymmetries and centroid shifts for a sample of Sloan Digital Sky Survey clusters with high-quality, archival X-ray data from Chandra and XMM-Newton. The three optical relaxation measures considered are the shape of the member-galaxy projected velocity distribution - measured by the Anderson-Darling (AD) statistic, the stellar mass gap between the most-massive and second-most-massive cluster galaxy, and the offset between the most-massive galaxy (MMG) position and the luminosity-weighted cluster centre. The AD statistic and stellar mass gap correlate significantly with X-ray relaxation proxies, with the AD statistic being the stronger correlator. Conversely, we find no evidence for a correlation between X-ray asymmetry or centroid shift and the MMG offset. High-mass clusters (Mhalo > 1014.5 M⊙) in this sample have X-ray asymmetries, centroid shifts, and Anderson-Darling statistics which are systematically larger than for low-mass systems. Finally, considering the dichotomy of Gaussian and non-Gaussian clusters (measured by the AD test), we show that the probability of being a non-Gaussian cluster correlates significantly with X-ray asymmetry but only shows a marginal correlation with centroid shift. These results confirm the shape of the radial velocity distribution as a useful proxy for cluster relaxation, which can then be applied to large redshift surveys lacking extensive X-ray coverage.

  10. Observation of Interfractional Variations in Lung Tumor Position Using Respiratory Gated and Ungated Megavoltage Cone-Beam Computed Tomography

    International Nuclear Information System (INIS)

    Chang, Jenghwa; Mageras, Gig S.; Yorke, Ellen; De Arruda, Fernando; Sillanpaa, Jussi; Rosenzweig, Kenneth E.; Hertanto, Agung; Pham, Hai; Seppi, Edward; Pevsner, Alex; Ling, C. Clifton; Amols, Howard

    2007-01-01

    Purpose: To evaluate the use of megavoltage cone-beam computed tomography (MV CBCT) to measure interfractional variation in lung tumor position. Methods and Materials: Eight non-small-cell lung cancer patients participated in the study, 4 with respiratory gating and 4 without. All patients underwent MV CBCT scanning at weekly intervals. Contoured planning CT and MV CBCT images were spatially registered based on vertebral anatomy, and displacements of the tumor centroid determined. Setup error was assessed by comparing weekly portal orthogonal radiographs with digitally reconstructed radiographs generated from planning CT images. Hypothesis testing was performed to test the statistical significance of the volume difference, centroid displacement, and setup uncertainty. Results: The vertebral bodies and soft tissue portions of tumor within lung were visible on the MV CBCT scans. Statistically significant systematic volume decrease over the course of treatment was observed for 1 patient. The average centroid displacement between simulation CT and MV CBCT scans were 2.5 mm, -2.0 mm, and -1.5 mm with standard deviations of 2.7 mm, 2.7 mm, and 2.6 mm in the right-left, anterior-posterior and superior-inferior directions. The mean setup errors were smaller than the centroid shifts, while the standard deviations were comparable. In most cases, the gross tumor volume (GTV) defined on the MV CBCT was located on average at least 5 mm inside a 10 mm expansion of the GTV defined on the planning CT scan. Conclusions: The MV CBCT technique can be used to image lung tumors and may prove valuable for image-guided radiotherapy. Our conclusions must be verified in view of the small patient number

  11. Finger pressure adjustments to various object configurations during precision grip in humans and monkeys.

    Science.gov (United States)

    Viaro, Riccardo; Tia, Banty; Coudé, Gino; Canto, Rosario; Oliynyk, Andriy; Salmas, Paola; Masia, Lorenzo; Sandini, Giulio; Fadiga, Luciano

    2017-06-01

    In this study, we recorded the pressure exerted onto an object by the index finger and the thumb of the preferred hand of 18 human subjects and either hand of two macaque monkeys during a precision grasping task. The to-be-grasped object was a custom-made device composed by two plates which could be variably oriented by a motorized system while keeping constant the size and thus grip dimension. The to-be-grasped plates were covered by an array of capacitive sensors to measure specific features of finger adaptation, namely pressure intensity and centroid location and displacement. Kinematic measurements demonstrated that for human subjects and for monkeys, different plate configurations did not affect wrist velocity and grip aperture during the reaching phase. Consistently, at the instant of fingers-plates contact, pressure centroids were clustered around the same point for all handle configurations. However, small pressure centroid displacements were specifically adopted for each configuration, indicating that both humans and monkeys can display finger adaptation during precision grip. Moreover, humans applied stronger thumb pressure intensity, performed less centroid displacement and required reduced adjustment time, as compared to monkeys. These pressure patterns remain similar when different load forces were required to pull the handle, as ascertained by additional measurements in humans. The present findings indicate that, although humans and monkeys share common features in motor control of grasping, they differ in the adjustment of fingertip pressure, probably because of skill and/or morphology divergences. Such a precision grip device may form the groundwork for future studies on prehension mechanisms. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. Macro-level safety analysis of pedestrian crashes in Shanghai, China.

    Science.gov (United States)

    Wang, Xuesong; Yang, Junguang; Lee, Chris; Ji, Zhuoran; You, Shikai

    2016-11-01

    Pedestrian safety has become one of the most important issues in the field of traffic safety. This study aims at investigating the association between pedestrian crash frequency and various predictor variables including roadway, socio-economic, and land-use features. The relationships were modeled using the data from 263 Traffic Analysis Zones (TAZs) within the urban area of Shanghai - the largest city in China. Since spatial correlation exists among the zonal-level data, Bayesian Conditional Autoregressive (CAR) models with seven different spatial weight features (i.e. (a) 0-1 first order, adjacency-based, (b) common boundary-length-based, (c) geometric centroid-distance-based, (d) crash-weighted centroid-distance-based, (e) land use type, adjacency-based, (f) land use intensity, adjacency-based, and (g) geometric centroid-distance-order) were developed to characterize the spatial correlations among TAZs. Model results indicated that the geometric centroid-distance-order spatial weight feature, which was introduced in macro-level safety analysis for the first time, outperformed all the other spatial weight features. Population was used as the surrogate for pedestrian exposure, and had a positive effect on pedestrian crashes. Other significant factors included length of major arterials, length of minor arterials, road density, average intersection spacing, percentage of 3-legged intersections, and area of TAZ. Pedestrian crashes were higher in TAZs with medium land use intensity than in TAZs with low and high land use intensity. Thus, higher priority should be given to TAZs with medium land use intensity to improve pedestrian safety. Overall, these findings can help transportation planners and managers understand the characteristics of pedestrian crashes and improve pedestrian safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Candidate soil indicators for monitoring the progress of constructed wetlands toward a natural state: a statistical approach

    Science.gov (United States)

    Stapanian, Martin A.; Adams, Jean V.; Fennessy, M. Siobhan; Mack, John; Micacchion, Mick

    2013-01-01

    A persistent question among ecologists and environmental managers is whether constructed wetlands are structurally or functionally equivalent to naturally occurring wetlands. We examined 19 variables collected from 10 constructed and nine natural emergent wetlands in Ohio, USA. Our primary objective was to identify candidate indicators of wetland class (natural or constructed), based on measurements of soil properties and an index of vegetation integrity, that can be used to track the progress of constructed wetlands toward a natural state. The method of nearest shrunken centroids was used to find a subset of variables that would serve as the best classifiers of wetland class, and error rate was calculated using a five-fold cross-validation procedure. The shrunken differences of percent total organic carbon (% TOC) and percent dry weight of the soil exhibited the greatest distances from the overall centroid. Classification based on these two variables yielded a misclassification rate of 11% based on cross-validation. Our results indicate that % TOC and percent dry weight can be used as candidate indicators of the status of emergent, constructed wetlands in Ohio and for assessing the performance of mitigation. The method of nearest shrunken centroids has excellent potential for further applications in ecology.

  14. Depth of interaction detection for {gamma}-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain)], E-mail: lerche@ific.uv.es; Doering, M. [Institut fuer Kernphysik, Forschungszentrum Juelich GmbH, D52425 Juelich (Germany); Ros, A. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain); Herrero, V.; Gadea, R.; Aliaga, R.J.; Colom, R.; Mateo, F.; Monzo, J.M.; Ferrando, N.; Toledo, J.F.; Martinez, J.D.; Sebastia, A. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain); Sanchez, F.; Benlloch, J.M. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain)

    2009-03-11

    A novel design for an inexpensive depth of interaction capable detector for {gamma}-ray imaging has been developed. The design takes advantage of the strong correlation between the width of the scintillation light distribution in monolithic crystals and the interaction depth of {gamma}-rays. We present in this work an inexpensive modification of the commonly used charge dividing circuits which enables the instantaneous and simultaneous computation of the second order moment of light distribution. This measure provides a good estimate for the depth of interaction and does not affect the determination of the position centroids and the energy release of {gamma}-ray impact. The method has been tested with a detector consisting of a monolithic LSO block sized 42x42x10mm{sup 3} and a position-sensitive photomultiplier tube H8500 from Hamamatsu. The mean spatial resolution of the detector was found to be 3.4mm for the position centroids and 4.9mm for the DOI. The best spatial resolutions were observed at the center of the detector and yielded 1.4mm for the position centroids and 1.9mm for the DOI.

  15. Effects of instructed timing and tempo on snare drum sound in drum kit performance.

    Science.gov (United States)

    Danielsen, Anne; Waadeland, Carl Haakon; Sundt, Henrik G; Witek, Maria A G

    2015-10-01

    This paper reports on an experiment investigating the expressive means with which performers of groove-based musics signal the intended timing of a rhythmic event. Ten expert drummers were instructed to perform a rock pattern in three different tempi and three different timing styles: "laid-back," "on-the-beat," and "pushed." The results show that there were systematic differences in the intensity and timbre (i.e., sound-pressure level, temporal centroid, and spectral centroid) of series of snare strokes played with these different timing styles at the individual level. A common pattern was found across subjects concerning the effect of instructed timing on sound-pressure level: a majority of the drummers played laid-back strokes louder than on-the-beat strokes. Furthermore, when the tempo increased, there was a general increase in sound-pressure level and a decrease in spectral centroid across subjects. The results show that both temporal and sound-related features are important in order to indicate that a rhythmic event has been played intentionally early, late, or on-the-beat, and provide insight into the ways in which musicians communicate at the microrhythmic level in groove-based musics.

  16. Depth of interaction detection for γ-ray imaging

    International Nuclear Information System (INIS)

    Lerche, Ch.W.; Doering, M.; Ros, A.; Herrero, V.; Gadea, R.; Aliaga, R.J.; Colom, R.; Mateo, F.; Monzo, J.M.; Ferrando, N.; Toledo, J.F.; Martinez, J.D.; Sebastia, A.; Sanchez, F.; Benlloch, J.M.

    2009-01-01

    A novel design for an inexpensive depth of interaction capable detector for γ-ray imaging has been developed. The design takes advantage of the strong correlation between the width of the scintillation light distribution in monolithic crystals and the interaction depth of γ-rays. We present in this work an inexpensive modification of the commonly used charge dividing circuits which enables the instantaneous and simultaneous computation of the second order moment of light distribution. This measure provides a good estimate for the depth of interaction and does not affect the determination of the position centroids and the energy release of γ-ray impact. The method has been tested with a detector consisting of a monolithic LSO block sized 42x42x10mm 3 and a position-sensitive photomultiplier tube H8500 from Hamamatsu. The mean spatial resolution of the detector was found to be 3.4mm for the position centroids and 4.9mm for the DOI. The best spatial resolutions were observed at the center of the detector and yielded 1.4mm for the position centroids and 1.9mm for the DOI.

  17. A study on high speed wavefront control algorithm for an adaptive optics system

    International Nuclear Information System (INIS)

    Park, Seung Kyu; Baik, Sung Hoon; Kim, Cheol Jung; Seo, Young Seok

    2000-01-01

    We developed a high speed control algorithm and system for measuring and correcting the wavefront distortions based on Windows operating system. To get quickly the information of wavefront distortion from the Hartman spot image, we preprocessed the image to remove background noises and extracted the centroid position by finding the center of weights. We moved finely the centroid position with sub-pixel resolution repeatedly to get the wavefront information with more enhanced resolution. We designed a differential data communication driver and an isolated analog driver to have robust system control. As the experimental results, the measurement resolution of the wavefront was 0.05 pixels and correction speed was 5Hz

  18. Skeletonized wave-equation inversion for Q

    KAUST Repository

    Dutta, Gaurav

    2016-09-06

    A wave-equation gradient optimization method is presented that inverts for the subsurface Q distribution by minimizing a skeletonized misfit function ε. Here, ε is the sum of the squared differences between the observed and the predicted peak/centroid frequency shifts of the early-arrivals. The gradient is computed by migrating the observed traces weighted by the frequency-shift residuals. The background Q model is perturbed until the predicted and the observed traces have the same peak frequencies or the same centroid frequencies. Numerical tests show that an improved accuracy of the inverted Q model by wave-equation Q tomography (WQ) leads to a noticeable improvement in the migration image quality.

  19. γ -Ray Generation from Plasma Wakefield Resonant Wiggler

    Science.gov (United States)

    Lei, Bifeng; Wang, Jingwei; Kharin, Vasily; Zepf, Matt; Rykovanov, Sergey

    2018-03-01

    A flexible gamma-ray radiation source based on the resonant laser-plasma wakefield wiggler is proposed. The wiggler is achieved by inducing centroid oscillations of a short laser pulse in a plasma channel. Electrons (self-)injected in such a wakefield experience both oscillations due to the transverse electric fields and energy gain due to the longitudinal electric field. The oscillations are significantly enhanced when the laser pulse centroid oscillations are in resonance with the electron betatron oscillations, extending the radiation spectrum to the gamma-ray range. The polarization of the radiation can be easily controlled by adjusting the injection of the laser pulse into the plasma channel.

  20. Skeletonized wave-equation inversion for Q

    KAUST Repository

    Dutta, Gaurav; Schuster, Gerard T.

    2016-01-01

    A wave-equation gradient optimization method is presented that inverts for the subsurface Q distribution by minimizing a skeletonized misfit function ε. Here, ε is the sum of the squared differences between the observed and the predicted peak/centroid frequency shifts of the early-arrivals. The gradient is computed by migrating the observed traces weighted by the frequency-shift residuals. The background Q model is perturbed until the predicted and the observed traces have the same peak frequencies or the same centroid frequencies. Numerical tests show that an improved accuracy of the inverted Q model by wave-equation Q tomography (WQ) leads to a noticeable improvement in the migration image quality.

  1. Di-μ-chlorido-bis{chlorido[(R/(S-1,5-diphenyl-3-(2-pyridyl-κN-2-pyrazoline-κN2]zinc(II}

    Directory of Open Access Journals (Sweden)

    Miquel Barceló-Oliver

    2010-08-01

    Full Text Available In the centrosymmetric binuclear title compound, [Zn2Cl4(C20H17N32], the coordination geometry of the ZnII ion can be described as a distorted ZnN2Cl3 trigonal bipyramid (τ = 0.89, arising from the N,N′-bidentate ligand, a terminal chloride ion and two bridging chloride ions. The N atoms occupy one axial and one equatorial site and the terminal chloride ion occupies an equatorial site. The dihedral angle between the pyridine and pyrazole rings is 12.8 (2°. In the crystal, aromatic π–π stacking [centroid–centroid separations = 3.812 (3 and 3.848 (3 Å] and C—H...Cl and C—H...π interactions help to establish the packing.

  2. Bis(2,6-dihydroxybenzoato-κ2O1,O1′(nitrato-κ2O,O′bis(1,10-phenanthroline-κ2N,N′cerium(III

    Directory of Open Access Journals (Sweden)

    Hongxiao Jin

    2011-01-01

    Full Text Available The mononuclear title complex, [Ce(C7H5O32(NO3(C12H8N22], is isostructural to other related lanthanide structures. The Ce atom is in a pseudo-bicapped square-antiprismatic geometry formed by four N atoms from two chelating 1,10-phenanthroline (phen ligands and by six O atoms, four from two 2,6-dihydroxybenzoate (DHB ligands and the other two from a nitrate anion. π–π stacking interactions between phen and DHB ligands [centroid–centroid distances = 3.513 (3 and 3.762 (2 Å] and phen and phen ligands [face-to-face separation = 3.423 (7 Å] of adjacent complexes stabilize the crystal structure. Intramolecular O—H...O hydrogen bonds are observed in the DHB ligands.

  3. Crystal structure of 4-(1H-indol-3-yl-2-(4-methoxyphenyl-6-phenylpyridine-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    R. Vishnupriya

    2014-10-01

    Full Text Available In the title compound, C27H19N3O, the dihedral angles between the plane of the pyridine ring and those of the indole (r.m.s. deviation = 0.018 Å, phenyl and methoxybenzene substituents are 33.60 (6, 25.28 (7 and 49.31 (7°, respectively. The N atom of the carbonitrile group is significantly displaced [0.288 (2 Å] from the plane of the pyridine ring, perhaps due to steric crowding. In the crystal, inversion dimers linked by pairs of N—H...Nn (n = nitrile hydrogen bonds generate R22(16 loops. Aromatic π–π stacking [centroid–centroid separation = 3.6906 (7 Å] and very weak C—H...π interactions are also observed".

  4. Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6cadmate(II dihydrate

    Directory of Open Access Journals (Sweden)

    Najmeh Firoozi

    2008-10-01

    Full Text Available In the title compound, (C4H14N2[Cd(C7H3NO42]·2H2O, the CdII ion is coordinated by four O atoms [Cd—O = 2.2399 (17–2.2493 (17 Å] and two N atoms [Cd—N = 2.3113 (15 and 2.3917 (15 Å] from two tridentate pyridine-2,6-dicarboxylato ligands in a distorted octahedral geometry. The uncoordinated water molecules are involved in O—H...O and N—H...O hydrogen bonds, which contribute to the formation of a three-dimensional supramolecular structure, along with π–π stacking interactions [centroid–centroid distances of 3.5313 (13 and 3.6028 (11 Å between the pyridine rings of neighbouring dianions].

  5. 2-Amino-4-methylpyridinium 2-hydroxybenzoate

    Directory of Open Access Journals (Sweden)

    Madhukar Hemamalini

    2010-08-01

    Full Text Available The asymmetric unit of the title molecular salt, C6H9N2+·C7H5O3−, contains two cations and two anions. Both the salicylate anions contain an intramolecular O—H...O hydrogen bond, which generates an S(6 ring. Both the 2-amino-4-methylpyridine molecules are protonated at their pyridine N atoms. In the crystal, both cations form two N—H...O hydrogen bonds to their adjacent anions, forming ion pairs. Further N—H...O links generate sheets lying parallel to the ab plane. In addition, weak C—H...O bonds and aromatic π–π stacking interactions [centroid–centroid distances = 3.5691 (9 and 3.6215 (9 Å] are observed between the cations and anions.

  6. 2-(5-Chloro-2-oxoindolin-3-ylidenehydrazinecarbothioamide

    Directory of Open Access Journals (Sweden)

    Viviane Conceição Duarte de Bittencourt

    2014-01-01

    Full Text Available The title molecule, C9H7ClN4OS, is almost planar, with an r.m.s. deviation of 0.034 (2 Å for the mean plane through all the non-H atoms. Intramolecular N—H...O and N—H...N hydrogen bonds form S(6 and S(5 ring motifs, respectively. In the crystal, molecules are assembled into inversion dimers through pairs of co-operative N—H...Cl interactions. These dimers are connected along the b axis by N—H...O and N—H...S hydrogen bonds, generating layers parallel to (103. The layers are further connected along the a axis into a three-dimensional network, through weak π–π stacking interactions [centroid–centroid distance = 3.849 (2 Å].

  7. (E-4-[7-(2,3-Dihydrothieno[3,4-b][1,4]dioxin-5-yl-2,1,3-benzothiadiazol-4-yl]-2-[(neopentyliminomethyl]phenol

    Directory of Open Access Journals (Sweden)

    Lauren A. Mitchell

    2014-08-01

    Full Text Available In the title molecule, C24H23N3O3S2, the benzothiadiazole ring system is essentially planar, with an r.m.s. deviation of 0.020 (8 Å. The thiophene and hydroxy-substitiuted rings form dihedral angles of 23.43 (9 and 35.45 (9°, respectively, with the benzothiadiazole ring system. An intramolecular O—H...N hydrogen bond is observed. In the crystal, weak C—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.880 (3 Å] link molecules into chains along [100]. In addition, there are short S...S contacts [3.532 (3 Å] which link these chains, forming a two-dimensional network parallel to (010.

  8. (Benzoato-κObis(1,10-phenanthroline-κ2N,N′copper(II chloride benzoic acid disolvate

    Directory of Open Access Journals (Sweden)

    Wen-Xiang Huang

    2010-05-01

    Full Text Available In the title complex, [Cu(C7H5O2(C12H8N22]Cl·2C6H5COOH, the CuII ion is coordinated by one carboxylate O atom from a benzoate anion and four N atoms from two phenantroline ligands in a distorted five-coordinate trigonal-bipyramidal CuON4 chromophore. The Cu2+ and the Cl− ion are imposed by a twofold rotation axiss which also bisects the equally disordered benzoate anion. In the crystal, the molecules are assembled into chains along [010] by C—H...Cl, O—H...Cl and C—H...O hydrogen-bonding interactions. The resulting chains are further connected into two-dimensional supramolecular layers parallel to [100] by interchain π...π stacking interactions [centroid–centroid distance = 3.823 (5 Å] between the phenanthroline ligands and the benzoic acid molecules, and by C—H...O hydrogen-bonding interactions. Strong π...π stacking interactions between adjacent phenantroline ligands [3.548 (4 Å] assemble the layers into a three-dimensional supramolecular architecture.

  9. Etude structurale et vibrationnelle d'un nouveau composé complexe de cobalt: [Co(imidazole)4Cl]Cl.

    Science.gov (United States)

    Derbel, Amira; Mhiri, Tahar; Graia, Mohsen

    2015-10-01

    In the title complex, chlorido-tetra-kis-(1H-imidazole-κN (3))cobalt(II) chloride, [CoCl(C3H4N2)4]Cl, the Co(II) cation has a distorted square-pyramidal coordination environment. It is coordinated by four N atoms of four imidazole (Im) groups in the basal plane, and by a Cl atom in the apical position. It is isostructural with [Cu(Im)4Cl]Cl [Morzyk-Ociepa et al. (2012 ▸). J. Mol. Struct. 1028, 49-56] and [Cu(Im)4Br]Br [Hossaini Sadr et al. (2004 ▸). Acta Cryst. E60, m1324-m1326]. In the crystal, the [CoCl(C3H4N2)4](+) cations and Cl(-) anions are linked via N-H⋯Cl hydrogen bonds, forming layers parallel to (010). These layers are linked via C-H⋯Cl hydrogen bonds and C-H⋯π and π-π [inter-centroid distance = 3.794 (2) Å] inter-actions, forming a three-dimensional framework. The IR spectrum shows vibrational bands typical for imidazol groups. The monoclinic unit cell of the title compound emulates an ortho-rhom-bic cell as its β angle is close to 90°. The crystal is twinned, with the refined ratio of twin components being 0.569 (1):0.431 (1).

  10. Tumor and normal tissue motion in the thorax during respiration: Analysis of volumetric and positional variations using 4D CT

    International Nuclear Information System (INIS)

    Weiss, Elisabeth; Wijesooriya, Krishni; Dill, S. Vaughn; Keall, Paul J.

    2007-01-01

    Purpose: To investigate temporospatial variations of tumor and normal tissue during respiration in lung cancer patients. Methods and Materials: In 14 patients, gross tumor volume (GTV) and normal tissue structures were manually contoured on four-dimensional computed tomography (4D-CT) scans. Structures were evaluated for volume changes, centroid (center of mass) motion, and phase dependence of variations relative to inspiration. Only volumetrically complete structures were used for analysis (lung in 2, heart in 8, all other structures in >10 patients). Results: During respiration, the magnitude of contoured volumes varied up to 62.5% for GTVs, 25.5% for lungs, and 12.6% for hearts. The range of maximum three-dimensional centroid movement for individual patients was 1.3-24.0 mm for GTV, 2.4-7.9 mm for heart, 5.2-12.0 mm for lungs, 0.3-5.5 mm for skin markers, 2.9-10.0 mm for trachea, and 6.6-21.7 mm for diaphragm. During respiration, the centroid positions of normal structures varied relative to the centroid position of the respective GTV by 1.5-8.1 mm for heart, 2.9-9.3 mm for lungs, 1.2-9.2 mm for skin markers, 0.9-7.1 mm for trachea, and 2.7-16.4 mm for diaphragm. Conclusion: Using 4D-CT, volumetric changes, positional alterations as well as changes in the position of contoured structures relative to the GTV were observed with large variations between individual patients. Although the interpretation of 4D-CT data has considerable uncertainty because of 4D-CT artifacts, observer variations, and the limited acquisition time, the findings might have a significant impact on treatment planning

  11. Niche tracking and rapid establishment of distributional equilibrium in the house sparrow show potential responsiveness of species to climate change.

    Directory of Open Access Journals (Sweden)

    William B Monahan

    Full Text Available The ability of species to respond to novel future climates is determined in part by their physiological capacity to tolerate climate change and the degree to which they have reached and continue to maintain distributional equilibrium with the environment. While broad-scale correlative climatic measurements of a species' niche are often described as estimating the fundamental niche, it is unclear how well these occupied portions actually approximate the fundamental niche per se, versus the fundamental niche that exists in environmental space, and what fitness values bounding the niche are necessary to maintain distributional equilibrium. Here, we investigate these questions by comparing physiological and correlative estimates of the thermal niche in the introduced North American house sparrow (Passer domesticus. Our results indicate that occupied portions of the fundamental niche derived from temperature correlations closely approximate the centroid of the existing fundamental niche calculated on a fitness threshold of 50% population mortality. Using these niche measures, a 75-year time series analysis (1930-2004 further shows that: (i existing fundamental and occupied niche centroids did not undergo directional change, (ii interannual changes in the two niche centroids were correlated, (iii temperatures in North America moved through niche space in a net centripetal fashion, and consequently, (iv most areas throughout the range of the house sparrow tracked the existing fundamental niche centroid with respect to at least one temperature gradient. Following introduction to a new continent, the house sparrow rapidly tracked its thermal niche and established continent-wide distributional equilibrium with respect to major temperature gradients. These dynamics were mediated in large part by the species' broad thermal physiological tolerances, high dispersal potential, competitive advantage in human-dominated landscapes, and climatically induced

  12. Source Parameter Inversion for Recent Great Earthquakes from a Decade-long Observation of Global Gravity Fields

    Science.gov (United States)

    Han, Shin-Chan; Riva, Ricccardo; Sauber, Jeanne; Okal, Emile

    2013-01-01

    We quantify gravity changes after great earthquakes present within the 10 year long time series of monthly Gravity Recovery and Climate Experiment (GRACE) gravity fields. Using spherical harmonic normal-mode formulation, the respective source parameters of moment tensor and double-couple were estimated. For the 2004 Sumatra-Andaman earthquake, the gravity data indicate a composite moment of 1.2x10(exp 23)Nm with a dip of 10deg, in agreement with the estimate obtained at ultralong seismic periods. For the 2010 Maule earthquake, the GRACE solutions range from 2.0 to 2.7x10(exp 22)Nm for dips of 12deg-24deg and centroid depths within the lower crust. For the 2011 Tohoku-Oki earthquake, the estimated scalar moments range from 4.1 to 6.1x10(exp 22)Nm, with dips of 9deg-19deg and centroid depths within the lower crust. For the 2012 Indian Ocean strike-slip earthquakes, the gravity data delineate a composite moment of 1.9x10(exp 22)Nm regardless of the centroid depth, comparing favorably with the total moment of the main ruptures and aftershocks. The smallest event we successfully analyzed with GRACE was the 2007 Bengkulu earthquake with M(sub 0) approx. 5.0x10(exp 21)Nm. We found that the gravity data constrain the focal mechanism with the centroid only within the upper and lower crustal layers for thrust events. Deeper sources (i.e., in the upper mantle) could not reproduce the gravity observation as the larger rigidity and bulk modulus at mantle depths inhibit the interior from changing its volume, thus reducing the negative gravity component. Focal mechanisms and seismic moments obtained in this study represent the behavior of the sources on temporal and spatial scales exceeding the seismic and geodetic spectrum.

  13. APLIKASI METODE-METODE AGGLOMERATIVE DALAM ANALISIS KLASTER PADA DATA TINGKAT POLUSI UDARA

    Directory of Open Access Journals (Sweden)

    Dewi Rachmatin

    2014-09-01

    Full Text Available ABSTRAK   Analisis Klaster merupakan analisis pengelompokkan data yang mengelompokkan data berdasarkan informasi yang ditemukan pada data. Tujuan dari analisis klaster adalah agar objek-objek di dalam satu kelompok memiliki kesamaan satu sama lain sedangkan dengan objek-objek yang berbeda kelompok memiliki perbedaan. Analisis klaster dibagi menjadi dua metode yaitu metode hirarki dan metode non-hirarki. Metode hirarki dibagi menjadi dua, yaitu metode agglomerative (pemusatan dan metode divisive (penyebaran. Metode-metode yang termasuk dalam metode agglomerative adalah Single Linkage Method, Complete Linkage Method, Average Linkage Method, Ward’s Method, Centroid Method dan Median Method. Pada artikel ini dibahas metode-metode agglomerative tersebut yang diterapkan pada data tingkat polusi udara. Masing-masing metode tersebut memberikan jumlah klaster yang berbeda.   Kata Kunci : Analisis Klaster, Single Linkage Method, Complete Linkage Method, Average Linkage Method, Ward’s Method, Centroid Method dan Median Method.     ABSTRACT Cluster analysis is an analysis of the data classification based on information found in the data.The objective of cluster analysis is that the objects in the group have in common with each other, while the different objects have different groups. Cluster analysis is divided into two methods : the method of non-hierarchical and hierarchical methods.Hierarchical method is divided into two methods, namely agglomerative methods (concentration and divisive methods (deployment. The methods included in the agglomerative method is Single Linkage Method, Complete Linkage Method, Average Linkage Method, Ward 's Method, Method and Median Centroid Method. In this article discussed the agglomerative methods were applied to the data rate of air pollution. Each of these methods provides a different number of clusters.   Keywords: Cluster Analysis , Single Linkage Method, Complete Linkage Method, Average Linkage Method, Ward

  14. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine

    Energy Technology Data Exchange (ETDEWEB)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo [University of Ljubljana, Faculty of Electrical Engineering, Trzaska 25, SI-1000 Ljubljana (Slovenia)

    2008-04-07

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm ({+-}0.6 mm) for the first and 2.1 mm ({+-}1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and

  15. Quantitative analysis of spinal curvature in 3D: application to CT images of normal spine

    International Nuclear Information System (INIS)

    Vrtovec, Tomaz; Likar, Bostjan; Pernus, Franjo

    2008-01-01

    The purpose of this study is to present a framework for quantitative analysis of spinal curvature in 3D. In order to study the properties of such complex 3D structures, we propose two descriptors that capture the characteristics of spinal curvature in 3D. The descriptors are the geometric curvature (GC) and curvature angle (CA), which are independent of the orientation and size of spine anatomy. We demonstrate the two descriptors that characterize the spinal curvature in 3D on 30 computed tomography (CT) images of normal spine and on a scoliotic spine. The descriptors are determined from 3D vertebral body lines, which are obtained by two different methods. The first method is based on the least-squares technique that approximates the manually identified vertebra centroids, while the second method searches for vertebra centroids in an automated optimization scheme, based on computer-assisted image analysis. Polynomial functions of the fourth and fifth degree were used for the description of normal and scoliotic spinal curvature in 3D, respectively. The mean distance to vertebra centroids was 1.1 mm (±0.6 mm) for the first and 2.1 mm (±1.4 mm) for the second method. The distributions of GC and CA values were obtained along the 30 images of normal spine at each vertebral level and show that maximal thoracic kyphosis (TK), thoracolumbar junction (TJ) and maximal lumbar lordosis (LL) on average occur at T3/T4, T12/L1 and L4/L5, respectively. The main advantage of GC and CA is that the measurements are independent of the orientation and size of the spine, thus allowing objective intra- and inter-subject comparisons. The positions of maximal TK, TJ and maximal LL can be easily identified by observing the GC and CA distributions at different vertebral levels. The obtained courses of the GC and CA for the scoliotic spine were compared to the distributions of GC and CA for the normal spines. The significant difference in values indicates that the descriptors of GC and CA

  16. Electron-beam-charged dielectrics: Internal charge distribution

    Science.gov (United States)

    Beers, B. L.; Pine, V. W.

    1981-01-01

    Theoretical calculations of an electron transport model of the charging of dielectrics due to electron bombardment are compared to measurements of internal charge distributions. The emphasis is on the distribution of Teflon. The position of the charge centroid as a function of time is not monotonic. It first moves deeper into the material and then moves back near to the surface. In most time regimes of interest, the charge distribution is not unimodal, but instead has two peaks. The location of the centroid near saturation is a function of the incident current density. While the qualitative comparison of theory and experiment are reasonable, quantitative comparison shows discrepancies of as much as a factor of two.

  17. Path-integral and Ornstein-Zernike study of quantum fluid structures on the crystallization line

    International Nuclear Information System (INIS)

    Sesé, Luis M.

    2016-01-01

    Liquid neon, liquid para-hydrogen, and the quantum hard-sphere fluid are studied with path integral Monte Carlo simulations and the Ornstein-Zernike pair equation on their respective crystallization lines. The results cover the whole sets of structures in the r-space and the k-space and, for completeness, the internal energies, pressures and isothermal compressibilities. Comparison with experiment is made wherever possible, and the possibilities of establishing k-space criteria for quantum crystallization based on the path-integral centroids are discussed. In this regard, the results show that the centroid structure factor contains two significant parameters related to its main peak features (amplitude and shape) that can be useful to characterize freezing.

  18. Path-integral and Ornstein-Zernike study of quantum fluid structures on the crystallization line

    Energy Technology Data Exchange (ETDEWEB)

    Sesé, Luis M., E-mail: msese@ccia.uned.es [Departamento de Ciencias y Técnicas Fisicoquímicas, Universidad Nacional de Educación a Distancia, Paseo Senda del Rey 9, 28040 Madrid (Spain)

    2016-03-07

    Liquid neon, liquid para-hydrogen, and the quantum hard-sphere fluid are studied with path integral Monte Carlo simulations and the Ornstein-Zernike pair equation on their respective crystallization lines. The results cover the whole sets of structures in the r-space and the k-space and, for completeness, the internal energies, pressures and isothermal compressibilities. Comparison with experiment is made wherever possible, and the possibilities of establishing k-space criteria for quantum crystallization based on the path-integral centroids are discussed. In this regard, the results show that the centroid structure factor contains two significant parameters related to its main peak features (amplitude and shape) that can be useful to characterize freezing.

  19. Uses of microchannel plate intensified detectors for imaging applications in the X-ray, EUV and visible wavelength regions

    International Nuclear Information System (INIS)

    Read, P.D.; Carter, M.K.; Pike, C.D.; Harrison, R.A.; Kent, B.J.; Swinyard, B.M.; Patchett, B.E.; Redfern, R.M.; Shearer, A.; Colhoun, M.

    1997-01-01

    The Rutherford Appleton laboratory photon counting detector (RALPCD) has been refined to meet project requirements for a flexible imaging arrangement with applications at X-ray, EUV and visible wavelengths. The basic detector design comprises commercially available high gain microchannel plate intensifiers fibre optically coupled to CID or CCD cameras, to form a modular detector arrangement with the appropriate RAL detection and centroiding software. Frames of data from the cameras are detected and centroided in a transputer or C40 parallel processor array where correction algorithms use look up tables to produce pattern free images at high resolution. Data from completed applications are used to illustrate the performance and future advances are discussed. (orig.)

  20. Statistical moments of the angular spectrum of normal waves in a turbulent collisional magnetized plasma

    International Nuclear Information System (INIS)

    Aistov, A.V.; Gavrilenko, V.G.

    1996-01-01

    The normal incidence of a small-amplitude electromagnetic wave upon a semi-infinite turbulent collisional plasm with an oblique external magnetic field is considered. Within a small-angle-scattering approximation of the radiative transport theory, a system of differential equations is derived for statistical moments of the angular power spectrum of radiation. The dependences of the spectrum centroid, dispersion, and asymmetry on the depth of penetration are studied numerically. The nonmonotonic behavior of the dispersion is revealed, and an increase in the spectrum width with absorption anisotropy is found within some depth interval. It is shown that, at large depths, the direction of the displacement of the spectrum centroid, does not always coincide with the direction of minimum absorption