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Sample records for abcd ring structure

  1. Synthesis of the ABCD and ABCDE ring systems of azaspiracid-1†‡

    Zhou, Xiao-Ti; Carter, Rich G.

    2004-01-01

    The efficient syntheses of the ABCD ring system of the originally proposed structure of azaspiracid-1 and the ABCDE ring system of the revised structure of azaspiracid-1 containing the correct stereochemistry at C6, C10, C13, C14, C16, C17, C19, C21, C22, C24 and C25 have been achieved.

  2. Synthesis of 10-epi-ABCDE ring fragment of pectenotoxin 2

    Aho, Jatta

    2009-01-01

    The pectenotoxins (PTXs) are a family of marine macrolactones produced by Dinophysis dinoflagellates and found in coastal areas worldwide. The PTXs have drawn considerable attention not only because of their complex structure and toxicity but also because of their potential medical applications. Pectenotoxins have shown selective cytotoxicity against a variety cancer cell lines and they are known to interact with the actin cytoskeleton by unique mechanism. These properties could be of great c...

  3. The Structure of Saturn's Rings

    Colwell, J. E.; Nicholson, P. D.; Tiscareno, M. S.; Murray, C. D.; French, R. G.; Marouf, E. A.

    Our understanding of the structure of Saturn's rings has evolved steadily since their discovery by Galileo Galilei in 1610. With each advance in observations of the rings over the last four centuries, new structure has been revealed, starting with the recognition that the rings are a disk by Huygens in 1656 through discoveries of the broad organization of the main rings and their constituent gaps and ringlets to Cassini observations that indirectly reveal individual clumps of particles tens of meters in size. The variety of structure is as broad as the range in scales. The main rings have distinct characteristics on a spatial scale of 104 km that suggest dramatically different evolution and perhaps even different origins. On smaller scales, the A and C ring and Cassini Division are punctuated by gaps from tens to hundreds of kilometer across, while the B ring is littered with unexplained variations in optical depth on similar scales. Moons are intimately involved with much of the structure in the rings. The outer edges of the A and B rings are shepherded and sculpted by resonances with the Janus—Epimetheus coorbitals and Mimas, respectively. Density waves at the locations of orbital resonances with nearby and embedded moons make up the majority of large-scale features in the A ring. Moons orbiting within the Encke and Keeler gaps in the A ring create those gaps and produce wakes in the nearby ring. Other gaps and wave-like features await explanation. The largest ring particles, while not massive enough to clear a gap, produce localized propeller-shaped disturbances hundreds of meters long. Particles throughout the A and B rings cluster into strands or self-gravity wakes tens of meters across that are in equilibrium between gravitational accretion and Keplerian shear. In the peaks of strong density waves particles pile together in a cosmic traffic jam that results in kilometer-long strands that may be larger versions of self-gravity wakes. The F ring is a showcase

  4. Lactose metabolism by Staphylococcus aureus: characterization of lacABCD, the structural genes of the tagatose 6-phosphate pathway.

    Rosey, E L; Oskouian, B; Stewart, G. C.

    1991-01-01

    The nucleotide and deduced amino acid sequences of the lacA and lacB genes of the Staphylococcus aureus lactose operon (lacABCDFEG) are presented. The primary translation products are polypeptides of 142 (Mr = 15,425) and 171 (Mr = 18,953) amino acids, respectively. The lacABCD loci were shown to encode enzymes of the tagatose 6-phosphate pathway through both in vitro studies and complementation analysis in Escherichia coli. A serum aldolase assay, modified to allow detection of the tagatose ...

  5. Generalized Double Ring Network Structures

    Pedersen, Jens Myrup; Patel, A.; Knudsen, Thomas Phillip; Madsen, Ole Brun

    This paper describes and studies generalizations of the well-known double ring network structures. Two classes of structures are studied, the N2R(p; q) and N2R(p; q; r) structures, of which the former is a special case of the well known Generalized Petersen Graphs. Basic properties of these...... distances and diameters is evaluated and compared to the performance of double rings. This comparison shows that the N2R(p; q) structures are superior to the double rings with regard to distances. For example, a N2R(p; q) structure with 1000 nodes has average distance 12 and diameter 18, while a similar...... structures are shown, indicating that they forma suitable base for future access network infrastructures. The first result is that every N2R(p; q; r) structure is isomorphic to a N2R(p; q) structure N2R(p; q'), and it is shown how q' is determined. Consequently, the rest of the paper focuses on the N2R(p; q...

  6. Domain structure of circular and ring magnets

    We present the results of a study of the domain structure and the magnetization reversal processes in arrays of circular and ring magnets, obtained by magnetic force microscopy and magnetization measurements. The particles, with outer diameter 0.55 and 2.2 μm, were made of Permalloy films of thickness 24 and 66 nm. In the circular elements two domain configurations were observed: a vortex structure with perpendicular magnetization at the core and a 'bud' state. In the ring elements the domain structure was found to depend on the ring width: a flux closed state was formed in wide rings and the 'onion' state was observed in narrow rings

  7. Delay-insensitive Multi-ring Structures

    Sparsø, Jens; Staunstrup, Jørgen

    1993-01-01

    This paper describes a set of simple design and performance analysis techniques that have been successfully used to design a number of non-trivial delay-insensitive circuits. Examples are building blocks for digital filters and a vector multiplier using a serial-parallel multiply and accumulate...... algorithm. The vector multiplier has been laid out, submitted for fabrication, and successfully tested. This design is described in detail to illustrate the design and the performance analysis techniques. The design technique is based on a data flow approach using pipelines and rings that are composed into...... larger multi-ring structures. For this restricted class of structures, it becomes possible - even for circuits of realistic size and complexity - to analyze the performance and establish an understanding of the bottlenecks. The paper combines a number of previously published results and techniques, and...

  8. Bifurcation structure of an optical ring cavity

    Kubstrup, C.; Mosekilde, Erik

    1996-01-01

    One- and two-dimensional continuation techniques are applied to determine the basic bifurcation structure for an optical ring cavity with a nonlinear absorbing element (the Ikeda Map). By virtue of the periodic structure of the map, families of similar solutions develop in parameter space. Within...... the individual family, the organization of the solutions exhibit an infinite number of regulatory arranged domains, the so-called swallow tails. We discuss the origin of this structure which has recently been observed in a variety of other systems as well....

  9. Structure in narrow planetary rings: Open questions and recent results

    Luis Benet; Olivier Merlo

    2010-01-01

    In this paper we review some open questions in the context of the structure observed in narrow planetary rings, and summarize some recent results of our work directed to answer them. Using the scattering approach to narrow rings we have succeeded to reproduce some of their structural properties in a qualitative sense, using unrealistic toy models as examples. We obtain narrow rings which are non-circular and display sharp edges. In addition, these rings may have multiple components which may ...

  10. The Structure of gr-simple Rings

    朱彬

    2003-01-01

    A characterization of gr-simple rings is given by using the notion of componentwise-dense subrings of a full matrix ring over a division ring. As a conse-quence, any G-graded full matrix ring over a division ring is isomorphic to a dense subring of a full matrix ring with a good G-grading. Some conditions for a grading of a full matrix ring to be isomorphic to a good one are given, which generalize some results in: Dáscáscu, S., Lon, B., Niǎstǎsescu, C. and Montes, J. R., Group gradingson full matrix rings, J. Algebra, 220(1999), 709-728.

  11. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Chuanjun Han; Han Zhang; Jie Zhang

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficie...

  12. Ring and Volcano Structures Formed by a Metal Dipyrromethene Complex

    Son, Seung Bae; Hahn, Jae Ryang [Chonbuk National Univ., Jeonju (Korea, Republic of); Miao, Qing; Shin, Jiyoung; Dolphin, David [Univ. of British Columbia, Columbia (Canada)

    2014-06-15

    Dichloromethane liquid droplets containing a cobalt dipyrromethene trimer deposited on a graphite surface were found to form coffee ring, toroid ring, or volcano dot structures due to the redistribution of the solute during solvent evaporation. The shapes and size distributions of the ring structures depended on the drying temperature. The shape differences were attributed to the fact that the solvent evaporation rate controlled the self-assembly process that yielded the coffee stain and pinhole structures.

  13. Optical system defect propagation in ABCD systems

    McKinley, W.G.; Yura, H.T.; Hanson, Steen Grüner

    1988-01-01

    We describe how optical system defects (tilt/jitter, decenter, and despace) propagate through an arbitrary paraxial optical system that can be described by an ABCD ray transfer matrix. A pedagogical example is given that demonstrates the effect of alignment errors on a typical optical system...

  14. Radiation from structured-ring resonators

    Maling, B; Craster, R V

    2016-01-01

    We investigate the scalar-wave resonances of systems composed of identical Neumann-type inclusions arranged periodically around a circular ring. Drawing on natural similarities with the undamped Rayleigh-Bloch waves supported by infinite linear arrays, we deduce asymptotically the exponentially small radiative damping in the limit where the ring radius is large relative to the periodicity. In our asymptotic approach, locally linear Rayleigh-Bloch waves that attenuate exponentially away from the ring are matched to a ring-scale WKB-type wave field. The latter provides a descriptive physical picture of how the mode energy is transferred via tunnelling to a circular evanescent-to-propagating transition region a finite distance away from the ring, from where radiative grazing rays emanate to the far field. Excluding the zeroth-order standing-wave modes, the position of the transition circle bifurcates with respect to clockwise and anti-clockwise contributions, resulting in striking spiral wavefronts.

  15. Electronic Properties of Semiconductor Quantum-Ring Structures

    Pacheco, Mónica; Fuster, Gonzalo; Barticevic, Zdenka

    2002-03-01

    Motivated by the interesting electronic properties exhibited by these nanorings when they are threaded by a magnetic field, we studied a new semiconductor structure formed by two coupled rings which are concentrically disposed. In order to calculate the two-ring electronic spectrum it is assumed that the in-plane electronic-potential of each ring is generated by a rotation, around the ring axis, of a one-dimensional parabolic potential centered to a distance ρ=ρo of the ring center. The potential of the two-rings system is then assumed as a superposition of a potential for each ring with their minimum at different radii and being truncated in the intersection point. In this way a potential barrier is formed in between the rings. We solve the in-plane problem by expanding the corresponding envelope function as a linear combination of solutions of isolated rings. We have made a detailed study about the influence of the characteristic confinement-parameters of each rings, and of the barrier strength, on the electronic energy spectrum of the system. A uniform magnetic field is applied along the common ring axis and we explore the effects on the Aharonov-Bohm-type oscillations in the energy levels caused by the particular geometry of two coupled quantum-rings.

  16. Control of slow light in a ring-out-ring structure

    Wang Nan; Zhang Yun-Dong; Yuan Ping

    2011-01-01

    This paper proposes a ring-out-ring structure of coupled optical resonators to yield coupled-resonator-induced transparency(GRIT). Considering the insertion loss of the coupler, it theoretically deduces the transmission and the effective phase shift. The influences of the insertion loss of the coupler on the transmittance, the effective phase shift,the group index and the CRIT linewidth are fully studied. We find that the increase in multiple m can effectively enhance the normal dispersion and the group index of the proposed structure. Moreover, the specific expression of the group index at resonance is theoretically deduced and discussed for the proposed structure with two rings. The result shows that the multiple m between the lengths of ring 1 and ring 2 can enhance the group index to m times that of the structure with two equal-sized rings at resonance. The control of slow light in the proposed structure is important for applications of highly sensitivity gyroscopes, optical delay lines and optical buffers, etc.

  17. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Han, Chuanjun

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  18. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring.

    Han, Chuanjun; Zhang, Han; Zhang, Jie

    2015-01-01

    In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal. PMID:27019582

  19. Structural Design and Sealing Performance Analysis of Biomimetic Sealing Ring

    Chuanjun Han

    2015-01-01

    Full Text Available In order to reduce the failure probability of rubber sealing rings in reciprocating dynamic seal, a new structure of sealing ring based on bionics was designed. The biomimetic ring has three concave ridges and convex bulges on each side which are very similar to earthworms. Bulges were circularly designed and sealing performances of the biomimetic ring in both static seal and dynamic seal were simulated by FEM. In addition, effects of precompression, medium pressure, speed, friction coefficient, and material parameters on sealing performances were discussed. The results show that von Mises stress of the biomimetic sealing ring distributed symmetrically in no-pressure static sealing. The maximum von Mises stress appears on the second bulge of the inner side. High contact stress concentrates on left bulges. Von Mises stress distribution becomes uneven under medium pressure. Both von Mises stress and contact stress increase when precompression, medium pressure, and rubber hardness increase in static sealing. Biomimetic ring can avoid rolling and distortion in reciprocating dynamic seal, and its working life is much longer than O-ring and rectangular ring. The maximum von Mises stress and contact stress increase with the precompression, medium pressure, rubber hardness, and friction coefficient in reciprocating dynamic seal.

  20. Unicell structure for superconducting storage rings

    Mechanically integrated, magnetically decoupled storage rings were designed for a heavy ion collider for 100 GeV/amu Au, at B = 2.7T. New concepts were developed, including detailed engineering design and cost estimates. A ''unicell'' contains a half-cell of both rings within a single He vessel. The unicell design is optimized for economical mass production. Survey pads welded to the laminations provide external fiducials to locate the magnet cores. Roller bearing self aligning supports accommodate cool-down shrinkage. The design tolerates relative motion of components resulting from longitudinal shrinkage in the approx.15 m long unicell without affecting performance. Magnetic and physical lengths are the same, eliminating waste space. ''Achromatic'' quadrupoles with sextupoles at both ends are located on a common precision beam tube which aligns and supports a pick-up electrode. The unicell accommodates longer dipoles compared to conventional designs, reducing B/sub max/, stored energy, and the volume of iron and superconductor. Applications to future machines will be discussed

  1. Unicell structure for superconducting storage rings

    Danby, G.; DeVito, B.; Jackson, J.; Keohane, G.; Lee, Y.Y.; Phillips, R.; Plate, S.; Repeta, L.; Skaritka, J.; Smith, L.

    1985-01-01

    Mechanically integrated, magnetically decoupled storage rings were designed for a heavy ion collider for 100 GeV/amu Au, at B = 2.7T. New concepts were developed, including detailed engineering design and cost estimates. A ''unicell'' contains a half-cell of both rings within a single He vessel. The unicell design is optimized for economical mass production. Survey pads welded to the laminations provide external fiducials to locate the magnet cores. Roller bearing self aligning supports accommodate cool-down shrinkage. The design tolerates relative motion of components resulting from longitudinal shrinkage in the approx.15 m long unicell without affecting performance. Magnetic and physical lengths are the same, eliminating waste space. ''Achromatic'' quadrupoles with sextupoles at both ends are located on a common precision beam tube which aligns and supports a pick-up electrode. The unicell accommodates longer dipoles compared to conventional designs, reducing B/sub max/, stored energy, and the volume of iron and superconductor. Applications to future machines will be discussed.

  2. Gravitational Lensing by Ring-Like Structures

    Lake, Ethan

    2016-01-01

    We study a class of gravitational lensing systems consisting of an inclined ring/belt, with and without an added point mass at the centre. We show that a common property of such systems is the so-called "pseudo-caustics", across which the magnification of a point source changes discontinuously and yet remains finite. Such a magnification change can be associated with either a change in image multiplicity or a sudden change in the size of one of the images. The existence of pseudo-caustics and the complex interplay between them and the formal caustics (corresponding to points of infinite magnification) can lead to interesting consequences, such as truncated or open caustics and the violation of Burke's theorem. The origin of the pseudo-caustics is found to be the discontinuity in the solutions to the lens equation across the ring/belt boundaries, and the pseudo-caustics correspond to these boundaries in the image (lens) plane. We provide a few illustrative examples to understand the pseudo-caustic features, an...

  3. Flat structures on the deformations of Gepner chiral rings

    Belavin, A

    2016-01-01

    We propose a simple method for the computation of the flat coordinates and Saito primitive forms on Frobenius manifolds of the deformations of Jacobi rings associated with isolated singularities. The method is based on using a conjecture about integral representations for the flat coordinates and on the Saito cohomology theory. This reduces the computation to a simple linear problem. We consider the case of the deformed Gepner chiral rings. The knowledge of the flat structures of Frobenius manifolds can be used for exact solution of the models of the topological conformal field theories corresponding to these chiral rings.

  4. Storage ring mass spectrometry for nuclear structure and astrophysics research

    Zhang, Y. H.; Litvinov, Yu A.; Uesaka, T.; Xu, H. S.

    2016-07-01

    In the last two and a half decades ion storage rings have proven to be powerful tools for precision experiments with unstable nuclides in the realm of nuclear structure and astrophysics. There are presently three storage ring facilities in the world at which experiments with stored radioactive ions are possible. These are the ESR in GSI, Darmstadt/Germany, the CSRe in IMP, Lanzhou/China, and the R3 storage ring in RIKEN, Saitama/Japan. In this work, an introduction to the facilities is given. Selected characteristic experimental results and their impact in nuclear physics and astrophysics are presented. Planned technical developments and the envisioned future experiments are outlined.

  5. Complex-Valued ABCD Matrices and Speckle Metrology

    Hanson, Steen Grüner; Jakobsen, Michael Linde; Yura, Harold T.

    2016-01-01

    We demonstrate that within the paraxial ray approximation the propagation of light through a complex optical system can be formulated in terms of a Huygens principle expressed with the complete system’s ABCD-matrix elements. As such, propagation through an optical system reduces to that of calcul...... treated in order to show the benefits of the complex ABCD matrices....

  6. Analysis of regular structures third degree based on chordal rings

    Bujnowski, Slawomir; Dubalski, Bozydar; Pedersen, Jens Myrup;

    2009-01-01

    the first part of paper, formulas for the basic parameters diameter and average path length were derived using optimal/ideal graphs, and used for indicating transmission properties of the structures. These analytical results were confirmed by comparison to a large number of computations on real graphs......  This paper presents an analysis of modified chordal rings third degree (CR3m) and modified double ring structure (N2Rm), which can be used as models of real networks. The proposed solutions are novel and different from the ones currently used since they have two chords of different lengths. In...

  7. The three-dimensional structure of Saturn's E ring

    Hedman, M M; Hamilton, D P; Showalter, M R

    2011-01-01

    Saturn's diffuse E ring consists of many tiny (micron and sub-micron) grains of water ice distributed between the orbits of Mimas and Titan. Various gravitational and non-gravitational forces perturb these particles' orbits, causing the ring's local particle density to vary noticeably with distance from the planet, height above the ring-plane, hour angle and time. Using remote-sensing data obtained by the Cassini spacecraft in 2005 and 2006, we investigate the E-ring's three-dimensional structure during a time when the Sun illuminated the rings from the south at a high elevation angle (> 15 degrees). These observations show that the ring's vertical thickness grows with distance from Enceladus' orbit and its peak brightness density shifts from south to north of Saturn's equator plane with increasing distance from the planet. These data also reveal a localized depletion in particle density near Saturn's equatorial plane around Enceladus' semi-major axis. Finally, variations are detected in the radial brightness...

  8. Flow resistance of hydraulic cylinder piston ring seal structure

    According to the control rod hydraulic drive mechanism (CRHDM) and the characteristics of its hydraulic cylinder seal structure, the leaking ways of the hydraulic cylinder piston ring seal were analysed, its theoretical calculation model was built and its flow resistance formula based on the calculation model of differential pressure at the hydraulic cylinder piston ring seal was deduced. By analyzing the results of the CRHDM single cylinder experiment, constants in the formula of the flow resistance were obtained. Under the experimental condition, results from the formula and the experiment tally with each other. The formula and analysis would be helpful for the theoretical analysis and engineering design of the hydraulic cylinder piston ring seal structure. (author)

  9. Fresnel-Transform's Quantum Correspondence and Quantum Optical ABCD Law

    FAN Hong-Yi; HU Li-Yun

    2007-01-01

    @@ Corresponding to the Fresnel transform there exists a unitary operator in quantum optics theory, which could be known the Fresnel operator (FO). We show that the multiplication rule of the FO naturally leads to the quantum optical ABCD law. The canonical operator methods as mapping of ray-transfer ABCD matrix is explicitly shown by the normally ordered expansion of the FO through the coherent state representation and the technique of integration within an ordered product of operators. We show that time evolution of the damping oscillator embodies the quantum optical ABCD law.

  10. Design of delay insensitive circuits using multi-ring structures

    Sparsø, Jens; Staunstrup, Jørgen; Dantzer-Sørensen, Michael

    1992-01-01

    larger multi ring structures by the joining and forking of signals. The implementation is based on a small set of building blocks (latches, combinational circuits and switches) that are composed of C-elements and simple gates. By following this approach, delay insensitive circuits with nontrivial......The design and VLSI implementation of a delay insensitive circuit that computes the inner product of two vec·tors is described. The circuit is based on an iterative serial-parallel multiplication algorithm. The design is based on a data flow approach using pipelines and rings that are combined into...

  11. Structure of the yeast Bre1 RING domain

    Kumar, Pankaj; Wolberger, Cynthia

    2015-01-01

    Monoubiquitination of histone H2B at Lys123 in yeast plays a critical role in regulating transcription, mRNA export, DNA replication and the DNA damage response. The RING E3 ligase, Bre1, catalyzes monoubiquitination of H2B in concert with the E2 ubiquitin conjugating enzyme, Rad6. The crystal structure of a C-terminal fragment of Bre1 shows that the catalytic RING domain is preceded by an N-terminal helix that mediates coiled-coil interactions with a crystallographically related monomer. Homology modeling suggests that the human homologue of Bre1, RNF20/RNF40, heterodimerizes through similar coiled coil interactions. PMID:25864391

  12. The fine structure of the Saturnian ring system

    A dust disc within a planetary magnetosphere constitutes a novel type of dust-ring current. Such an azimuthal current carrying dust disc is subject to the dusty plasma analog of the well known finite-resistivity 'tearing' mode instability in regular plasma current sheets, at long wavelengths. It is proposed that the presently observed fine ringlet structure of the Saturnian ring system is a relic of this process operating at cosmogonic times and breaking up the initial proto-ring (which may be regarded as an admixture of fine dust and plasma) into an ensemble of thin ringlets. It is shown that this instability developes at a rate that is many orders of magnitude faster than any other known instability, when the disc thickness reaches a value that is comparable to its present observed value. (Auth.)

  13. [ABCDE--a systematic approach to critically ill patients].

    Thim, Troels; Krarup, Niels Henrik; Grove, Erik Lerkevang; Løfgren, Bo

    2010-11-22

    This systematic approach to the immediate assessment and treatment of the critically ill or injured patient is applicable in all clinical emergencies. The aim of the ABCDE approach is to facilitate immediate life-saving treatment and thus buy time for definite diagnosis and treatment by breaking down complex clinical situations into manageable parts. Application of the ABCDE approach may improve treatment quality. PMID:21092723

  14. Fresnel-transform's quantum correspondence and quantum optical ABCD Law

    Hongyi, Fan; Liyun, Hu

    2007-01-01

    Corresponding to Fresnel transform there exists a unitary operator in quantum optics theory, which could be named Fresnel operator (FO). We show that the multiplication rule of FO naturally leads to the quantum optical ABCD law. The canonical operator methods as mapping of ray-transfer ABCD matrix is explicitly shown by FO's normally ordered expansion through the coherent state representation and the technique of integration within an ordered product of operators. We show that time evolution ...

  15. Rings

    The essence of vortex physics is that at certain low-energy scales elementary excitations of a point particle theory can behave like strings rather than particles. Vortices are the resulting string-like solutions; their thickness sets the distance scale beyond which physics is string-like rather than particle-like. String degrees of freedom are massless in the sense that excitations on a string can have an arbitrarily low frequency. Non-string degrees of freedom correspond to massive particles and are absent from the low energy spectrum. This article considers only field theories with vortices at low energies. The possible existence of a class of solitons in these vortex theories will be discussed. They are vortex rings: they are localized and finite in energy, and able to carry the quantum numbers of point particles. Rings are thus particle-like solutions of a vortex theory, which is itself a limit of a point particle field theory

  16. Aromatic rings in chemical and biological recognition: energetics and structures.

    Salonen, Laura M; Ellermann, Manuel; Diederich, François

    2011-05-16

    This review describes a multidimensional treatment of molecular recognition phenomena involving aromatic rings in chemical and biological systems. It summarizes new results reported since the appearance of an earlier review in 2003 in host-guest chemistry, biological affinity assays and biostructural analysis, data base mining in the Cambridge Structural Database (CSD) and the Protein Data Bank (PDB), and advanced computational studies. Topics addressed are arene-arene, perfluoroarene-arene, S⋅⋅⋅aromatic, cation-π, and anion-π interactions, as well as hydrogen bonding to π systems. The generated knowledge benefits, in particular, structure-based hit-to-lead development and lead optimization both in the pharmaceutical and in the crop protection industry. It equally facilitates the development of new advanced materials and supramolecular systems, and should inspire further utilization of interactions with aromatic rings to control the stereochemical outcome of synthetic transformations. PMID:21538733

  17. Microlensing of a Ring Model for Quasar Structure

    Schild, R; Schild, Rudolph; Vakulik, Viktor

    2003-01-01

    Microlensing observations of the Q0957+561 A,B have consistently shown evidence for structure in the quasar that has not been evident in available microlensing models, where the luminous source has been consistently modeled as a single large round structure. We show that the microlensing features can easily be reproduced by a luminous quasar model motivated by observations; a luminous inner accretion disc edge and outer ring-shaped structures where the emission lines form. Such a model can explain all of the features known from 24 years of Q0957 microlensing observations.

  18. Transport in GaAs heterojunction ring structures

    Ford, C. J. B.; Thornton, T. J.; Newbury, R.; Pepper, M.; Ahmed, H.; Davies, G. J.; Andrews, D.

    In earlier work we have shown that the split gate GaAsAlGaAs heterojunction FET has been a very useful system for obtaining 1D transport. 1,2 We have now extended this work to the construction of ring structures. Here, a ring of resist (outside diameter 2.2μm, inside diameter 0.4μm) is formed on the AlGaAs surface using Electron Beam Lithography, and is covered with metal, thereby forming a Schottky gate inside and outside the ring. Application of a negative voltage to the gates depletes the high-mobility 2D electron gas at the interface, except in a narrow annulus between the gates. The width of this ring-shaped 2D electron gas can be varied by changing the gate voltage. The magnetoresistance has been measured for Tresistance, depending on gate voltage, and extending out to B˜1T. The quantum Hall effect is seen at high fields and yields unexpected non-zero plateaux in R xx for narrow channels.

  19. Nuclear structure studies with RI beams and cooler rings

    Selected topics in present days nuclear structure physics studied by reactions of RI beams are presented. They are change in nuclear radii, single particle orbitals, and shapes. Dynamical changes are shown for nuclei far from the stability line in particular in p-sd shell. Among the future reaction study, a thick target method for a storage ring is presented. A possibility to obtain the highest luminosity for an internal target experiment is proposed

  20. Structuring Light by Concentric-Ring Patterned Magnetic Metamaterial Cavities.

    Zeng, Jinwei; Gao, Jie; Luk, Ting S; Litchinitser, Natalia M; Yang, Xiaodong

    2015-08-12

    Ultracompact and tunable beam converters pose a significant potential for modern optical technologies ranging from classical and quantum communication to optical manipulation. Here we design and demonstrate concentric-ring patterned structures of magnetic metamaterial cavities capable of tailoring both polarization and phase of light by converting circularly polarized light into a vector beam with an orbital angular momentum. We experimentally illustrate the realization of both radially and azimuthally polarized vortex beams using such concentric-ring patterned magnetic metamaterials. These results contribute to the advanced complex light manipulation with optical metamaterials, making it one step closer to realizing the simultaneous control of polarization and orbital angular momentum of light on a chip. PMID:26121268

  1. Miniaturization and control of split ring structures from an analytic solution of their resonance

    Chui, S. T.; Zhang, Y.; Xzhou, Lei

    2008-01-01

    We derived simple polynomial equations to determine the entire resonance spectra of split ring structures. For double stacking split rings made with flat wires, we showed that the resonance frequency depends linearly on the ring-ring separation. In particular, we found that the wavelength of the lowest resonance mode can be made as large as the geometrical size of the ring for realistic experimental conditions, whereas for current systems this ratio is of the order of 10. Finite-difference-ti...

  2. Solar system history as recorded in the Saturnian ring structure

    Alfven, H.

    1983-01-01

    Holberg's analysis of the Voyager Saturn photographs in reflected and transparent light, and occultation data of stars seen through the rings are discussed. A hyperfine structure, with 10,000 ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interpret them as fossils, which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas, Janus and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase. The shadows are not simple void regions but exhibit a characteristic signature. Parts of the fine structure, explained by Holberg as resonances with satellites, are interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. Analysis of ring data can reconstruct the plasma-planetesimal transition with an accuracy of a few percent.

  3. ABCD: a functional database for the avian brain.

    Schrott, Aniko; Kabai, Peter

    2008-01-30

    Here we present the first database developed for storing, retrieving and cross-referencing neuroscience information about the connectivity of the avian brain. The Avian Brain Circuitry Database (ABCD) contains entries about the new and old terminology of the areas and their hierarchy, data on connections between brain regions, as well as a functional keyword system linked to brain regions and connections. Data were collected from the primary literature and textbooks, and an online submission system was developed to facilitate further data collection directly from researchers. The database aims to help spread the results of avian connectivity studies, the recently revised nomenclature and also to provide data for brain network research. ABCD is freely available at http://www.behav.org/abcd. PMID:17889371

  4. Frequency response of magnetoelectric effect in piezoelectric-magnetostrictive disk-ring composite structures

    Zhang Ru, E-mail: zhangruwl@njut.edu.cn [Department of Applied Physics, Nanjing University of Technology, Nanjing 210009 (China); Wu Gaojian; Zhang Li [Department of Applied Physics, Nanjing University of Technology, Nanjing 210009 (China); Li Xin [College of Electronics and Information engineering, Nanjing University of Technology, Nanjing 210009 (China); Zhang Ning [Department of Physics, Nanjing Normal University, Nanjing 210097 (China)

    2012-08-15

    A theoretical model is presented for frequency dependence of magnetoelectric (ME) effect in piezoelectric-magnetostrictive disk-ring composite structures. Expressions for ME voltage coefficients in piezoelectric-magnetostrictive (PE-MS) disk-ring and MS-PE disk-ring are obtained by solving elastodynamic equations. The calculated resonance frequency and frequency dependence of ME voltage coefficients are in good agreement with the experimental results. This model indicates better mechanical coupling in disk-ring structure than that in traditional layered structure, and this may be responsible for the enhancing ME effect. The analysis suggests the disk-ring composites structures are promising for magnetoelectric applications. - Highlights: Black-Right-Pointing-Pointer Frequency response of ME effect in PE-MS disk-ring composites structures is modeled. Black-Right-Pointing-Pointer The calculated results are in good agreement with the experimental results. Black-Right-Pointing-Pointer This model indicates better mechanical coupling in disk-ring structure.

  5. Graphical linking of MO multicenter bond index and VB structures. II-5-c rings and 6-c heterocyclic rings

    Bollini, C G; Giambiagi, M

    2001-01-01

    Through the graphical method proposed it is possible to set a link between an MO multicenter bond index and VB structures. The value of the index depends on the order of the atoms involved if they are more than three. For 5-c rings three basic structures are required; the eventually different values are 12. Unlike the 6-c case it may happen that different pairs of basic structures are used to build the same polygon. For the 6-c rings including heteroatoms the original degeneracy of benzene splits leading eventually to 60 different I sub r sub i sub n sub g values.

  6. One anlytic form for four branches of the ABCD matrix

    Baskal, S

    2010-01-01

    It is not always possible to diagonalize the optical $ABCD$ matrix, but it can be brought into one of the four Wigner matrices by a similarity transformation. It is shown that the four Wigner matrices can be combined into one matrix with four branches. This result is illustrated in terms of optical activities, laser cavities, and multilayer optics.

  7. Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

    Mao, Hann-Shin

    Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma structure and behavior of miniature ring-cusp discharges is required. A research model was fabricated to provide a simplified experimental test bed for the analysis of the plasma discharge chamber of a miniature ion thruster. The plasma source allowed for spatially resolved measurements with a Langmuir probe along a meridian plane. Probe measurements yielded plasma density, electron temperature, and plasma potential data. The magnetic field strength was varied along with the discharge current to determine the plasma behavior under various conditions. The structure of the plasma properties were found to be independent of the discharge power under the proper scaling. It was concluded that weaker magnetic fields can improve the overall performance for ion thruster operation. To further analyze the experimental measurements, a framework was developed based on the magnetic field. A flux aligned coordinate system was developed to decouple the perpendicular and parallel plasma motion with respect to the magnetic field. This was done using the stream function and magnetic scalar potential. Magnetic formulae provided intuition on the field profiles dependence on magnet dimensions. The flux aligned coordinate system showed that the plasma was isopycnic along constant stream function values. This was used to develop an empirical relation suitable for estimating the spatial behavior and to determine the plasma volume and loss areas. The plasma geometry estimates were applied to a control volume

  8. Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoinhibition of an Ariadne-family E3 and insights into ligation mechanism

    Duda, David M.; Olszewski, Jennifer L.; Schuermann, Jonathan P.; Kurinov, Igor; Miller, Darcie J.; Nourse, Amanda; Alpi, Arno F; Schulman, Brenda A.

    2013-01-01

    A distinctive mechanism for ubiquitin (Ub) ligation has recently been proposed for the RING1-IBR-RING2 (RBR) family of E3s: an N-terminal RING1 domain recruits a thioester-linked intermediate complex between Ub and the E2 UbcH7, and a structurally unique C-terminal RING2 domain displays a catalytic cysteine required for Ub ligation. To obtain insights into RBR E3s, we determined the crystal structure of the Human Homolog of Ariadne (HHARI), which reveals the individual RING1, IBR, and RING2 d...

  9. Kinetic resistance of hydraulic cylinder piston ring seal structure

    According to the step motion of single cylinder for Control Rod Hydraulic Drive Mechanism (CRHDM) and the characteristics of the hydraulic cylinder piston ring seal structure, the source of kinetic resistance during step motion process was analyzed, the theoretical model of the dynamic step motion process was built and the value of kinetic resistance based on the results of the control rod hydraulic drive mechanism single cylinder experiment was deduced. By analyzing the relationship between kinetic resistance and the dynamic parameters of the step motion process including the pressure and the velocity of the inner cylinder, calculation model of the kinetic resistance during the step motion process was obtained. The displacement curve inferred from this model agrees with the experimental data. This model would be helpful for the dynamic simulation of the step motion process and the stress analysis of the control rod hydraulic drive mechanism. (authors)

  10. Lens optics and the continuity problems of the ABCD matrix

    Baskal, S

    2014-01-01

    Paraxial lens optics is discussed to study the continuity properties of the $ABCD$ beam transfer matrix. The two-by-two matrix for the one-lens camera-like system can be converted to an equi-diagonal form by a scale transformation, leaving the off-diagonal elements invariant. It is shown that the matrix remains continuous during the focusing process, but this transition is not analytic. However, its first derivative is still continuous, which leads to the concept of "tangential continuity." It is then shown that this tangential continuity is applicable to $ABCD$ matrices pertinent to periodic optical systems, where the equi-diagonalization is achieved by a similarity transformation using rotations. It is also noted that both the scale transformations and the rotations can be unified within the framework of Hermitian transformations.

  11. Formation of a Propeller Structure by a Moonlet in a Dense Planetary Ring

    Michikoshi, Shugo

    2011-01-01

    The Cassini spacecraft discovered a propeller-shaped structure in Saturn's A ring. This propeller structure is thought to be formed by gravitational scattering of ring particles by an unseen embedded moonlet. Self-gravity wakes are prevalent in dense rings due to gravitational instability. Strong gravitational wakes affect the propeller structure. Here, we derive the condition for formation of a propeller structure by a moonlet embedded in a dense ring with gravitational wakes. We find that a propeller structure is formed when the wavelength of the gravitational wakes is smaller than the Hill radius of the moonlet. We confirm this formation condition by performing numerical simulations. This condition is consistent with observations of propeller structures in Saturn's A ring.

  12. An Efficient Inexact ABCD Method for Least Squares Semidefinite Programming

    Sun, Defeng; Toh, Kim-Chuan; Yang, Liuqin

    2015-01-01

    We consider least squares semidefinite programming (LSSDP) where the primal matrix variable must satisfy given linear equality and inequality constraints, and must also lie in the intersection of the cone of symmetric positive semidefinite matrices and a simple polyhedral set. We propose an inexact accelerated block coordinate descent (ABCD) method for solving LSSDP via its dual, which can be reformulated as a convex composite minimization problem whose objective is the sum of a coupled quadr...

  13. Synthesis of an arbitrary ABCD system with fixed lens positions.

    Bastiaans, Martin J; Alieva, Tatiana

    2006-08-15

    On the basis of the modified Iwasawa decomposition of a lossless first-order optical system as a cascade of a lens, a magnifier, and a so-called orthosymplectic system, we show how to synthesize an arbitrary ABCD system (with two transverse coordinates) by means of lenses and predetermined sections of free space such that the lenses are located at fixed positions. PMID:16880840

  14. Complete Synchronization of Coupled Hindmarsh-Rose Neurons with Ring Structure

    石霞; 陆启韶

    2004-01-01

    Complete synchronization of coupled Hindmarsh-Rose (HR) neurons with a ring structure is studied. The criterion for complete synchronization of coupled neurons with the ring structure is obtained through the stability analysis of the linearized synchronization error system. Numerical simulation is given to test the criterion for a system with three coupled HR neurons.

  15. Efficient substructure searching of large chemical libraries: the ABCD chemical cartridge.

    Agrafiotis, Dimitris K; Lobanov, Victor S; Shemanarev, Maxim; Rassokhin, Dmitrii N; Izrailev, Sergei; Jaeger, Edward P; Alex, Simson; Farnum, Michael

    2011-12-27

    Efficient substructure searching is a key requirement for any chemical information management system. In this paper, we describe the substructure search capabilities of ABCD, an integrated drug discovery informatics platform developed at Johnson & Johnson Pharmaceutical Research & Development, L.L.C. The solution consists of several algorithmic components: 1) a pattern mapping algorithm for solving the subgraph isomorphism problem, 2) an indexing scheme that enables very fast substructure searches on large structure files, 3) the incorporation of that indexing scheme into an Oracle cartridge to enable querying large relational databases through SQL, and 4) a cost estimation scheme that allows the Oracle cost-based optimizer to generate a good execution plan when a substructure search is combined with additional constraints in a single SQL query. The algorithm was tested on a public database comprising nearly 1 million molecules using 4,629 substructure queries, the vast majority of which were submitted by discovery scientists over the last 2.5 years of user acceptance testing of ABCD. 80.7% of these queries were completed in less than a second and 96.8% in less than ten seconds on a single CPU, while on eight processing cores these numbers increased to 93.2% and 99.7%, respectively. The slower queries involved extremely generic patterns that returned the entire database as screening hits and required extensive atom-by-atom verification. PMID:22035187

  16. The effect of metal field plates on multiguard structures with floating p+ guard rings

    The performance and stability of silicon diode detectors can be improved by implementing guard ring structures around the active detector area. The purpose of this work is to study design parameters influencing the performance of multiguard structures, especially the effect of metal field plates. An important feature is the potential distribution in the multiguard ring structure which depends on the bulk doping concentration, the oxide charge, the size of the gap between guard rings and the field-plate design. We have made a systematic investigation of the effect of distance between floating p+ guard rings with two different metal field plate designs. We have also varied the width of the field plates and studied the effect of gamma irradiation. Numerical simulations have been done to compare with results from the experimental potential distributions between guard rings. (orig.)

  17. On the structure of Stanley-Reisner rings associated to cyclic polytopes

    Boehm, Janko

    2009-01-01

    We study the structure of Stanley-Reisner rings associated to cyclic polytopes, using ideas from unprojection theory. Consider the boundary simplicial complex Delta(d,m) of the d-dimensional cyclic polytope with m vertices. We show how to express the Stanley-Reisner ring of Delta(d,m+1) in terms of the Stanley-Reisner rings of Delta(d,m) and Delta(d-2,m-1). As an application, we use the Kustin-Miller complex construction to identify the minimal graded free resolutions of these rings. In particular, we recover results of Schenzel, Terai and Hibi about their graded Betti numbers.

  18. Resilient MPLS-TP multicast service based on an Interconnected-Ring structure

    Zhang, Jiang; Berger, Michael Stübert; Ruepp, Sarah Renée

    2010-01-01

    This paper proposes two innovative schemes to ensure a reliable MPLS Transport Profile multicast service based on interconnected-ring structure. The proposed Two Working Paths Multicast Service uses both directions of the ring as working paths which increases the network resource efficiency...

  19. A No-Reference Sharpness Metric Based on Structured Ringing for JPEG2000 Images

    Zhipeng Cao

    2014-01-01

    Full Text Available This work presents a no-reference image sharpness metric based on human blur perception for JPEG2000 compressed image. The metric mainly uses a ringing measure. And a blurring measure is used for compensation when the blur is so severe that ringing artifacts are concealed. We used the anisotropic diffusion for the preliminary ringing map and refined it by considering the property of ringing structure. The ringing detection of the proposed metric does not depend on edge detection, which is suitable for high degraded images. The characteristics of the ringing and blurring measures are analyzed and validated theoretically and experimentally. The performance of the proposed metric is tested and compared with that of some existing JPEG2000 sharpness metrics on three widely used databases. The experimental results show that the proposed metric is accurate and reliable in predicting the sharpness of JPEG2000 images.

  20. Breakdown voltage analysis of field limiting ring structure

    In this paper, a computer based analysis is performed to study the effect of floating field-limiting rings (FLR) on the breakdown voltage of Si microstrip detectors. For optimum performance it is crucial to achieve the maximum breakdown voltage for Si detectors operated at very high bias due to extremely hostile radiation environment of LHC. The breakdown performance of Si microstrip detectors can be improved by implementing floating field-limiting rings (FLR) around the active detector area. In the present work, we propose a criterion for optimising the spacing of FLR with respect to the main junction. (author)

  1. Gravito-electrodynamics and the structure of planetary ring systems

    Mendis, D. A.

    1984-01-01

    Recent spacecraft observations of the Saturnian and Jovian ring systems have highlighted a plethora of interesting new phenomena associated with those regions containing fine (micron and sub-micron sized) dust. Recognizing that these dust grains, by virtue of being immersed within the planetary magnetospheres, are electrostatically charged to the point that they experience comparable gravitational and electric forces, a new 'gravito-electrodynamic' theory has been developed to describe their dynamics. This theory has been successful in explaining all these phenomena in a systematic way. In this review, the basic model and its range of validity are outlined, and its application to the Saturnian and Jovian ring systems are discussed.

  2. Activity of aalactic nuclei and ring-like structures in normal galaxies

    Formation mekhanism of ring-like structures in normal galaxies is discussed. The above structures observed in normal galaxies are possibly formed by shock waves generated by recurrent activity of galactic nuclei. Specific features of ring-like structures are connected with parameters (ener--gy and period) characterizing the activity of nuclei, and with gas distribution type in central regions of galaxies as well

  3. Structural and Pharmacological Effects of Ring-Closing Metathesis in Peptides

    Pål Rongved

    2010-09-01

    Full Text Available Applications of ring-closing alkene metathesis (RCM in acyclic α- and β-peptides and closely related systems are reviewed, with a special emphasis on the structural and pharmacological effects of cyclization by RCM.

  4. Structural and Pharmacological Effects of Ring-Closing Metathesis in Peptides

    Pål Rongved; Øyvind Jacobsen; Jo Klaveness

    2010-01-01

    Applications of ring-closing alkene metathesis (RCM) in acyclic α- and β-peptides and closely related systems are reviewed, with a special emphasis on the structural and pharmacological effects of cyclization by RCM.

  5. G345.45+1.50: An expanding ring-like structure with massive star formation

    Lopez-Calderon, Cristian; Nyman, Lars-Ake; Garay, Guido; de Gregorio-Monsalvo, Itziar; Bergman, Per

    2016-01-01

    Ring-like structures in the ISM are commonly associated with high-mass stars. Kinematic studies of large structures in GMCs toward these ring-like structures may help us to understand how massive stars form. The origin and properties of the ring-like structure G345.45+1.50 is investigated through observations of the 13CO(3-2) line. The aim of the observations is to determine the kinematics in the region and to compare physical characteristics estimated from gas emission with those previously determined using dust continuum emission. The 13CO(3-2) line was mapped toward the whole ring using the APEX telescope. The ring is found to be expanding with a velocity of 1.0 km/s, containing a total mass of 6.9e3 Msun, which agrees well with that determined using 1.2 mm dust continuum emission. An expansion timescale of 3e6 yr and a total energy of 7e46 erg are estimated. The origin of the ring might have been a supernova explosion, since a 35.5 cm source, J165920-400424, is located at the center of the ring without an...

  6. Guard Ring Width Impact on Impact Parameter Performances and Structure Simulations

    Gouldwell, A; Rahman, M; Bates, R; Wemyss, M; Murphy, G; Turner, P; Biagi, S F

    2003-01-01

    The 1 mm guard ring structure of the VELO sensors has been simulated. The performance of the baseline design is considered and a design which improves the electric field characteristics proposed. Designs which would permit a reduced guard ring width, to 0.5 mm or better, are also discussed and shown to also have similarly good electric field performances. The effect of implementing these designs on the impact parameter resolution of LHCb is found to be better than 5 %. This design is currently being fabricated. Finally, a very different structure, the trench guard ring, is considered which would then allow an impact parameter resolution improvement of approximately 7 %.

  7. Plasma Structure and Behavior of Miniature Ring-Cusp Discharges

    Mao, Hann-Shin

    2013-01-01

    Miniature ring-cusp ion thrusters provide a unique blend of high efficiencies and millinewton level thrust for future spacecraft. These thrusters are attractive as a primary propulsion for small satellites that require a high delta V, and as a secondary propulsion for larger spacecraft that require precision formation flying, disturbance rejection, or attitude control. To ensure desirable performance throughout the life of such missions, an advancement in the understanding of the plasma struc...

  8. Two phenomena: Honji instability, and ringing of offshore structures

    2011-01-01

    Honji instability and ringing of offshore structrures are two different phenomena. Honji instability occurs at a circular cylinder in transverse periodic finite motion in a water tank. It is superposed on the streaming flow induced by the cylinder's boundary layer. Its oscillation period is half of the period of the cylinder oscillation. Finite volume calculations of the filtered Navier-Stokes equations visualize the three-dimensional instability, where fluid particles transported by the circumferencial rol...

  9. Ring-closure Reaction to Novel Quinoline Derivatives and Their Structural Characterization

    L(U),Yin-Xiang(吕银祥); LAN,Bi-Jian(蓝碧健); ZHOU,Hui(周辉); XU,Wei(徐伟); WANG,Jing-Mei(王静梅); HUANG,Yong-Ming(黄永明)

    2004-01-01

    In the condensation of arylaldehydes with arylethylidenemalononitriles, it was found that, besides the normal product dienes a, the ring-closure product quinoline derivatives b can be also obtained in 26%-50% yields. The substituent effects were also examined and a possible reaction mechanism was proposed for the formation of b. The X-ray crystal structure of 1b confirms the structure of the ring-closure product.

  10. Matrix vaccination guidelines : 2015 ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries

    Hosie, Margaret J; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

    2015-01-01

    OVERVIEW: In 2013, the ABCD published 'Matrix vaccination guidelines: ABCD recommendations for indoor/outdoor cats, rescue shelter cats and breeding catteries' in a Special Issue of the Journal of Feline Medicine and Surgery (Volume 15, Issue 7, pages 540-544). The ABCD's vaccination recommendations

  11. Ordered patterns and structures via interfacial self-assembly: superlattices, honeycomb structures and coffee rings.

    Ma, Hongmin; Hao, Jingcheng

    2011-11-01

    Self-assembly is now being intensively studied in chemistry, physics, biology, and materials engineering and has become an important "bottom-up" approach to create intriguing structures for different applications. Self-assembly is not only a practical approach for creating a variety of nanostructures, but also shows great superiority in building hierarchical structures with orders on different length scales. The early work in self-assembly focused on molecular self-assembly in bulk solution, including the resultant dye aggregates, liposomes, vesicles, liquid crystals, gels and so on. Interfacial self-assembly has been a great concern over the last two decades, largely because of the unique and ingenious roles of this method for constructing materials at interfaces, such as self-assembled monolayers, Langmuir-Blodgett films, and capsules. Nanocrystal superlattices, honeycomb films and coffee rings are intriguing structural materials with more complex features and can be prepared by interfacial self-assembly on different length scales. In this critical review, we outline the recent development in the preparation and application of colloidal nanocrystal superlattices, honeycomb-patterned macroporous structures by the breath figure method, and coffee-ring-like patterns (247 references). PMID:21792458

  12. A new look back at the structure of Uranus' narrow rings

    Chancia, Robert O.; Hedman, Matthew M.; French, Richard G.

    2015-11-01

    With the Cassini mission to Saturn providing new insights into how rings work, a new examination of the available Uranus ring data will provide further insights into the rings’ structure and dynamics, as well as the planetary interior. We investigate the fine-scale quasiperiodic optical depth variations within the Uranian rings observed in the Voyager 2 radio and stellar occultations. Previous investigations of these patterns within the ɛ, δ, and γ rings suggested that some of these may be density waves at locations of eccentric Lindblad resonances with the satellites Cordelia and Ophelia (Porco and Goldreich 1987 AJ) as well as possible unidentified satellites (Horn et al. 1988 Icarus, Gresh et al. 1989 Icarus, and Yanamandra-Fisher 1992 ASR). We revisit these structures as well as others in the α, β, 4, 5, and 6 rings using modern analytical techniques in order to better constrain their origins. The α and β rings exhibit highly periodic patterns, which have very different wavelengths in the different occultation cuts (even after accounting for the ringlets’ width variations). We explore the possibility that these structures could be moonlet wakes, similar to those found in Saturn’s rings near the small moons Pan and Daphnis.

  13. Formation of ring structures in galactic disks during close passages of galaxies

    Tutukov, A. V.; Fedorova, A. V.

    2016-01-01

    The formation of ring structures in galactic disks is investigated. It is shown that, in addition to the known mechanism of forming rings in "head-on" collisions between galaxies, ring structures can be formed during close passages of galaxies if the perturbing galaxy moves in a plane close to the equatorial plane of the perturbed disk galaxy, opposite to the direction of rotation of the disk. Numerical simulations of the formation of structures in the disk of a massive galaxy undergoing a passage with another galaxy are considered. The results of these cmputations show the formation of pronounced ring structures in the galactic disk when the initial inclination of the trajectory of the perturbing galaxy to the equatorial plane of the perturbed galaxy is no more than ~25°. However, the probability of close passages of galaxies with these parameters is small, as is the probability of head-on collisions. The characteristic time scale for the existence of pronounced rings is of order the dynamical time scale at the edge of the galaxy, 200-300 million years, close to the corresponding time for head-on collisions. The evolution of the rings has the same character in both cases: they gradually expand and move toward the periphery of the galaxy. The results of these simulations can also be applied to a close passage of one star by another star with a protoplanetary disk. According to the computation results, the characteristic time scale for the existence of pronounced rings in such a protoplanetary disk depends mainly on the size of the disk; this time scale can reach several tens of thousands of years for a disk radius of about 1000 AU. The formation of ring structures in such a disk could influence the formation and evolution of planetesimals, and possibly the character of the formation of planets and the distribution of their orbital semi-major axes.

  14. Self-gravity wake structures in Saturn's a ring revealed by Cassini vims

    Hedman, M.M.; Nicholson, P.D.; Salo, H.; Wallis, B.D.; Buratti, B.J.; Baines, K.H.; Brown, R.H.; Clark, R.N.

    2007-01-01

    During the summer of 2005, the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft observed a series of occultations of the star o Ceti (Mira) by Saturn's rings. These observations revealed pronounced variations in the optical depth of the A ring with longitude, which can be attributed to oriented structures in the rings known as self-gravity wakes. While the wakes themselves are only tens of meters across and below the resolution of the measurements, we are able to obtain information about the orientation and shapes of these structures by comparing the observed transmission at different longitudes with predictions from a simple model. Our findings include the following: (1) The orientation of the wakes varies systematically with radius, trailing by between 64?? and 72?? relative to the local radial direction. (2) The maximum transmission peaks at roughly 8% for B = 3.45?? in the middle A ring (???129,000 km). (3) Both the wake orientation and maximum transmission vary anomalously in the vicinity of two strong density waves (Janus 5:4 and Mimas 5:3). (4) The ratio of the wake vertical thickness H to the wake pattern wavelength ?? (assuming infinite, straight, regularly-spaced wake structures) varies from 0.12 to 0.09 across the A ring. Gravitational instability theory predicts ?? ??? 60 m, which suggests that the wake structures in the A ring are only ???6 m thick. ?? 2007. The American Astronomical Society. All rights reserved.

  15. Structure of the c14 Rotor Ring of the Proton Translocating Chloroplast ATP Synthase*

    Vollmar, Melanie; Schlieper, Daniel; Winn, Martyn; Büchner, Claudia; Groth, Georg

    2009-01-01

    The structure of the membrane integral rotor ring of the proton translocating F1F0 ATP synthase from spinach chloroplasts was determined to 3.8 Å resolution by x-ray crystallography. The rotor ring consists of 14 identical protomers that are symmetrically arranged around a central pore. Comparisons with the c11 rotor ring of the sodium translocating ATPase from Ilyobacter tartaricus show that the conserved carboxylates involved in proton or sodium transport, respectively, are 10.6–10.8 Å apar...

  16. Saturn's Rings

    Cuzzi, J. N.

    2014-12-01

    The rings are changing before our eyes; structure varies on all timescales and unexpected things have been discovered. Many questions have been answered, but some answers remain elusive (see Cuzzi et al 2010 for a review). Here we highlight the major ring science progress over the mission to date, and describe new observations planned for Cassini's final three years. Ring Composition and particle sizes: The rings are nearly all water ice with no other ices - so why are they reddish? The C Ring and Cassini Division are "dirtier" than the more massive B and A Rings, as shown by near-IR and, recently, microwave observations. Particle sizes, from stellar and radio occultations, vary from place to place. Ring structure, micro and macro: numerous spiral density waves and ubiquitous "self-gravity wakes" reveal processes which fostered planet formation in the solar system and elsewhere. However, big puzzles remain regarding the main ring divisions, the C Ring plateau structures, and the B Ring irregular structure. Moonlets, inside and out, seen and unseen: Two gaps contain sizeable moonlets, but more gaps seem to contain none; even smaller embedded "propeller" objects wander, systematically or randomly, through the A ring. Rubble pile ringmoons just outside the rings may escaped from the rings, and the recently discovered "Peggy" may be trying this as we watch. Impact bombardment of the rings: Comet fragments set the rings to rippling on century-timescales, and boulders crash through hourly; meanwhile, the constant hail of infalling Kuiper belt material has a lower mass flux than previously thought. Origin and Age of the Rings: The ring mass and bombardment play key roles. The ring mass is well known everywhere but in the B Ring (where most of it is). New models suggest how tidal breakup of evolving moons may have formed massive ancient rings, of which the current ring is just a shadow. During its last three years, the Cassini tour profile will allow entirely new

  17. RT-ABCDE Strategy for Management and Prevention of Human Diseases

    HU Chun-song

    2008-01-01

    In this article,the authors summarized the RT-ABCDE strategy for the management and prevention of human diseases,which includes ReTrO-ABCDE(Examination regularity,Disease and risk factor control,Changing lifestyrle and reducing pathways of infection and spread,Biochemical and Antagonistic index control and therapeutic treatment as well as RT-Routine and Right Treatment).The RT-ABCDE strategy,a novel concept and an essential method,should be a routine strategy for disease control and prevention.It should be proposed and applied in both clinical and preventive medicine.

  18. Structural variations in aromatic 2-electron three-membered rings of the main group elements

    Dibyendu Mallick; Eluvathingal D Jemmis

    2015-02-01

    Structural variations of different 2-aromatic three-membered ring systems of main group elements, especially group 14 and 13 elements as compared to the classical description of cyclopropenyl cation has been reviewed in this article. The structures of heavier analogues as well as group 13 analogues of cyclopropenyl cation showed an emergence of dramatic structural patterns which do not conform to the generalnorms of carbon chemistry. Isolobal analogies between the main group fragments have been efficiently used to explain the peculiarities observed in these three-membered ring systems.

  19. Characteristics of a glass gem with a guard-ring structure

    We recently developed a Glass GEM (G-GEM), and it exhibited a superior performance compared with other gaseous detectors. We are currently developing a G-GEM with a single-sided guard ring structure, in order to improve its spark tolerance. In this research, we compared its performance with that of a conventional hole structure. The single-sided guard-ring structure has shown strong polarity when it was operated upside down, however, the similar output pulse shapes were observed for both cases. The gain curves were consistent with simulation results. The energy resolutions were also compared

  20. Comparing and Selecting Generalized Double Ring Network Structures

    Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun

    2004-01-01

    . These different structures have different properties, and choosing a best structure depends on what properties are considered important. For both research and planning purposes it is beneficial to have a simple scheme for optimally choosing q given p. We show that for structures of up to 4000 nodes it...

  1. An array of asymmetries in Saturn's structure revealed by its rings

    Hedman, Matthew M.; Nicholson, Philip D.; El Moutamid, Maryame; Graven, Stephanie

    2016-05-01

    Previous investigations of high-resolution stellar occultation data obtained by the Cassini spacecraft have revealed that Saturn's C ring contains numerous density waves that are probably generated by structures inside the planet. In particular, five features were attributed to long-lived asymmetries in the planet's gravity field because they had pattern speeds similar to the range of rotation rates found in Saturn's winds. Using wavelet-based techniques, we have performed a more comprehensive search for similar structures, and found that the above five waves are just the most obvious members of an entire population of ring disturbances spread over several thousand kilometers of the C ring. These structures should provide new insights into the dynamics of Saturn's deep atmosphere.

  2. Radially Polarized Bessel-Gauss Beams in ABCD Optical Systems and Fiber-Based Generation

    Schimpf, Damian; Putnam, William P.; Grogan, Michael D.; Ramachandran, Siddharth; Kaertner, Franz

    2013-01-01

    We derive solutions for radially polarized Bessel-Gauss beams in ABCD optical systems by superimposing decentered Gaussian beams with linear polarization states. We experimentally confirm the expression by employing a fiber-based mode-converter.

  3. Electronic structures of GaAs/Al x Ga1-x As quantum double rings

    Li Shu-Shen; Xia Jian-Bai

    2006-01-01

    AbstractIn the framework of effective mass envelope function theory, the electronic structures of GaAs/AlxGa1-xAs quantum double rings (QDRs) are studied. Our model can be used to calculate the electronic structures of quantum wells, wires, dots, and the single ring. In calculations, the effects due to the different effective masses of electrons and holes in GaAs and AlxGa1-xAs and the valence band mixing are considered. The energy levels of electrons and holes are calculated for different sh...

  4. AbCD: arbitrary coverage design for sequencing-based genetic studies

    Kang, Jian; Huang, Kuan-Chieh; Xu, Zheng; Wang, Yunfei; Abecasis, Gonçalo R.; Li, Yun

    2013-01-01

    Summary: Recent advances in sequencing technologies have revolutionized genetic studies. Although high-coverage sequencing can uncover most variants present in the sequenced sample, low-coverage sequencing is appealing for its cost effectiveness. Here, we present AbCD (arbitrary coverage design) to aid the design of sequencing-based studies. AbCD is a user-friendly interface providing pre-estimated effective sample sizes, specific to each minor allele frequency category, for designs with arbi...

  5. Microwave metamaterial absorber based on multiple square ring structures

    Weicheng Zhou

    2015-11-01

    Full Text Available In this paper, we report the design, analysis, and simulation of quintuple-band metamaterial absorber (MMA in the microwave region. The absorber is constructed of a delicate periodic patterned structures and a metallic background plane, separated by a dielectric substrate. By manipulating the periodic patterned structures, high absorption can be obtained at five specific resonance frequencies. Moreover, the significantly high absorptions of quintuple-peaks are persistent with polarization independence, and the influence of angle of incidence for both TE and TM modes was also elucidated. For explaining the absorption mechanism of proposed structures, the electric and magnetic field distributions and resistance matching principal were given. Importantly, the design idea has the ability to be extended to other frequencies, like terahertz, infrared and optical frequencies.

  6. Value of ABCD2 in predicting early ischemic stroke in patients diagnosed with transient ischemic attack.

    Mojtaba Chardoli

    2013-09-01

    Full Text Available As a significant number of patients diagnosed with transient ischemic attack (TIA at emergency department are at risk to develop TIA or cerebral vascular accident (CVA, several attempts have been made to figure out a predictive method to detect those at higher risk of such attacks. We aimed to evaluate the role of ABCD2 scoring which includes age, blood pressure, clinical symptoms, diabetes mellitus, and duration of symptoms in predicting short term outcome of the patients presenting with TIA. One hundred consecutive patients visited between 2009 and 2010 in Hazrat Rasoul Akram Hospital and diagnosed with TIA were enrolled and their ABCD2 scores were registered. The incidence of death, CVA, or TIA during the first week after the attack was recorded. Eleven patients suffered new TIA/CVA after 1 week. Sensitivity and specificity of ABCD2 score for predicting CVA/TIA at cut-off point of 4 were 72.7% and 52.8%, respectively. At the same cut-off point for ABCD2, positive and negative predictive values were 16% and 94 %, respectively. Our results show that although patients with ABCD2 score greater than 4 were more likely to develop recurrent TIA/CVA in short term, those with lesser score still harbour a considerable risk for TIA/CVA. Though ABCD2 as an easily applicable tool is very helpful in management of TIA patients at emergency department, but it should not be the only measure to rely on in our decision making.

  7. Incomplete cooling down of Saturn's A ring at solar equinox: Implication for seasonal thermal inertia and internal structure of ring particles

    Morishima, Ryuji; Brooks, Shawn; Deau, Estelle; Pilorz, Stu

    2015-01-01

    At the solar equinox in August 2009, the Composite Infrared Spectrometer (CIRS) onboard Cassini showed the lowest Saturn's ring temperatures ever observed. Detailed radiative transfer models show that the observed equinox temperatures of Saturn's A ring are much higher than model predictions as long as only the flux from Saturn is taken into account. This indicates that the A ring was not completely cooled down at the equinox. We develop a simple seasonal model for ring temperatures and first assume that the internal density and the thermal inertia of a ring particle are uniform with depth. The particle size is estimated to be 1-2 m. The seasonal thermal inertia is found to be 30-50 Jm$^{-2}$K$^{-1}$s$^{-1/2}$ in the middle A ring whereas it is $\\sim$ 10 Jm$^{-2}$K$^{-1}$s$^{-1/2}$ or as low as the diurnal thermal inertia in the inner and outermost regions of the A ring. An additional internal structure model, in which a particle has a high density core surrounded by a fluffy regolith mantle, shows that the c...

  8. Micro-flow synthesis and structural analysis of sterically crowded diimine ligands with five aryl rings

    Shinichiro Fuse

    2013-11-01

    Full Text Available Sterically crowded diimine ligands with five aryl rings were prepared in one step in good yields using a micro-flow technique. X-ray crystallographic analysis revealed the detailed structure of the bulky ligands. The nickel complexes prepared from the ligands exerted high polymerization activity in the ethylene homopolymerization and copolymerization of ethylene with polar monomers.

  9. Insect-inspired wing actuation structures based on ring-type resonators

    Bolsman, C.T.; Goosen, J.F.L.; Van Keulen, F.

    2008-01-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of

  10. Irradiation tests of double-sided silicon strip detectors with a special guard ring structure

    The results of the first irradiation tests of newly designed silicon microstrip detectors performed with 21 MeV protons at the Max-Planck-Institut in Heidelberg are presented. The detectors were developed and produced by the semiconductor laboratory of the Max-Planck-Institut in Munich. Novel guard ring structures allow operation of the detectors at voltages exceeding 300 V

  11. Interference enhancement and modulation introduced by surface plasmon polaritons in a concentric-ring structure

    Lai, Senfeng; Wu, Wen; Peng, Li; Gu, Wenhua

    2015-10-01

    This article studied the interference enhancement and modulation introduced by surface plasmon polaritons (SPPs) in a double-concentric-ring structure. Young's double-slit interference experiment is a classic experiment in the history of physics, and has many modifications with deep impacts in many areas including physics, optics, and electromagnetics. In this work, to use the classic bull's eye structure to produce the surface plasmon polariton effect, a double-concentricring- hole structure was used instead of the double-slit structure to generate optical interference, and the bull's eye structure was applied in the surroundings to generate surface plasmonic wave for modulation of the interference. For structure details, a concentric double-ring-hole was etched in a silver film, with a series of periodic concentric-ringshaped shallow grooves etched in both the upper and bottom surfaces of the silver films. Simulation results showed that the interference of the double-ring-hole could be modulated by SPPs, generating new transmission spectra with desired peak positions and intensities. The transmission peak intensity could be enhanced by 2 to 6 times. The proposed structure can be used as a powerful and convenient tool to adjust the transmission spectra, which can have promising applications in the design and implementation of optical devices for filtering and sensing, especially in the sub-wavelength structure size range.

  12. Silicon pixel detectors of a double-sided guard ring structure for radiation hardness

    Cho, Hyo Sung [Yonsei Univ., Wonju (Korea, Republic of); Chien, Chih Yung [Johns Hopkins Univ., Baltimore (United States)

    2003-08-01

    The lifetime of silicon detectors in a severe radiation environment at CERN LHC depends strongly upon careful detector design and material selection due to the anticipated radiation -induced damage. We recently fabricated more radiation-tolerant silicon pixel detectors of a double-sided guard ring structure. The electrical characterization of such detectors was performed before and after irradiation to neutron fluence (1Mev equivalent ) up to 6 x 10{sup 14} n/cm{sup 2} by measuring the leakage current, the full depletion voltage, and the potential distribution over the guard rings.

  13. In vivo structure of the E. coli FtsZ-ring revealed by photoactivated localization microscopy (PALM.

    Guo Fu

    Full Text Available The FtsZ protein, a tubulin-like GTPase, plays a pivotal role in prokaryotic cell division. In vivo it localizes to the midcell and assembles into a ring-like structure-the Z-ring. The Z-ring serves as an essential scaffold to recruit all other division proteins and generates contractile force for cytokinesis, but its supramolecular structure remains unknown. Electron microscopy (EM has been unsuccessful in detecting the Z-ring due to the dense cytoplasm of bacterial cells, and conventional fluorescence light microscopy (FLM has only provided images with limited spatial resolution (200-300 nm due to the diffraction of light. Hence, given the small sizes of bacteria cells, identifying the in vivo structure of the Z-ring presents a substantial challenge. Here, we used photoactivated localization microscopy (PALM, a single molecule-based super-resolution imaging technique, to characterize the in vivo structure of the Z-ring in E. coli. We achieved a spatial resolution of ∼35 nm and discovered that in addition to the expected ring-like conformation, the Z-ring of E. coli adopts a novel compressed helical conformation with variable helical length and pitch. We measured the thickness of the Z-ring to be ∼110 nm and the packing density of FtsZ molecules inside the Z-ring to be greater than what is expected for a single-layered flat ribbon configuration. Our results strongly suggest that the Z-ring is composed of a loose bundle of FtsZ protofilaments that randomly overlap with each other in both longitudinal and radial directions of the cell. Our results provide significant insight into the spatial organization of the Z-ring and open the door for further investigations of structure-function relationships and cell cycle-dependent regulation of the Z-ring.

  14. Enhanced strongly modulated spin transmission of Fano-Rashba mesoscopic ring structure

    One-dimensional Rashba quantum ring structure with two leads subjected to a weak external magnetic field is proposed as a possible candidate for spintronic current modulators. By tuning spin-orbit coupling and magnitude of external magnetic field, resonance and antiresonance behavior can be found in our investigation. Comparing with results in other structures like quantum wires with local or periodic Rashba interaction, the T-shaped structure, more broader energy range of vanishing small transmission and larger on/off transmission ratio can be found in the structure and Fano-Rashba interference behaviors of the quantum ring model. Moreover, it is found the enhanced robustness of these interference against random Anderson-type disorder of device, which may conduce to the real application of this device.

  15. Reducing support loss in micromechanical ring resonators using phononic band-gap structures

    Hsu, Feng-Chia; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin [Industrial Technology Research Institute-South, Tainan 709, Taiwan (China); Hsu, Jin-Chen, E-mail: fengchiahsu@itri.org.t, E-mail: hsujc@yuntech.edu.t [Department of Mechanical Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan (China)

    2011-09-21

    In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.

  16. Geomagnetic Tail and Ring Current Dynamics and Structure during July 6, 2013 magnetic storm

    Nazarkov, Ilya

    According to THEMIS and POES satellites the structure and spatial dimensions of ring current and geotal current system are restored. Using models of the main magnetic field of Earth (IGRF-11) and a magnetospheric magnetic field (A2000), the magnetic field of the currents other than the tail and the ring currents was subtracted from measurements. The hourly analysis of dynamics and position of current system of a tail was carried out. Evolution of ring current is estimated by data fluxes of STEB particles, measured by POES satellites at low latitudes. Isotropic boundary, determined by data of POES satellites, was projected to equatorial plane and compared with position of the inner edge of geomagnetic tail current, obtained from THEMIS measurements.

  17. Ring localized structures in nonlinear shallow water wave dynamics

    The nonlinear dynamics of the concentric shallow water waves is described by means of the cylindrical Korteweg-de Vries equation, often referred to as the concentric Korteweg-de Vries equation (cKdVE). By using the mapping that transforms a cKdVE into the standard one – hereafter also referred to as the planar Korteweg-de Vries equation (KdVE) – the spatiotemporal evolution of a cylindrical surface water wave, corresponding to a tilted cylindrical bright soliton, is described. The usual representation of a tilted soliton is 'non-physical'; here the cylindrical coordinate and the retarded time play the role of time-like and space-like variables, respectively. However, we show that, when we express such analytical solution of the cKdVE in the appropriate representation in terms of the two horizontal space coordinates, say X and Y, and the 'true' time, say T, this non-physical character disappears. The analysis is then carried out numerically to consider the surface water wave evolution corresponding to initially localized structures with standard boundary conditions, such as bright soliton, Gaussian and Lorentzian profiles. A comparison among those profiles is finally presented

  18. ROMY - The First Large 3D Ring Laser Structure for Seismology and Geodesy

    Schreiber, Karl Ulrich; Igel, Heiner; Wassermann, Joachim; Lin, Chin-Jen; Gebauer, André; Wells, Jon-Paul

    2016-04-01

    Large ring laser gyroscopes have matured to the point that they can routinely observe rotational motions from geophysical processes that can be used in geodesy and seismology. The ring lasers used for this purpose enclose areas between 16 and 800 square meters and have in common that they can only measure rotations around the vertical axis because the structures are horizontally placed on the floor. With the ROMY project we have embarked on the construction of a full 3-dimensional rotation sensor. The actual apparatus consists of four individual triangular ring lasers arranged in the shape of a tetrahedron with 12 m of length on each side. At each corner of the tetrahedron three of the ring lasers are rigidly tied together to the same mechanical reference. The overall size of the installation provides a promising compromise between sensor stability on one side and sensor resolution on the other side. This talk introduces the technical concept of the ROMY ring laser installation and will also briefly outline the requirements for applications in space geodesy.

  19. Electron correlation in C_(4N+2) carbon rings: aromatic vs. dimerized structures

    Torelli, Tommaso; Mitas, Lubos

    2000-01-01

    The electronic structure of C_(4N+2) carbon rings exhibits competing many-body effects of Huckel aromaticity, second-order Jahn-Teller and Peierls instability at large sizes. This leads to possible ground state structures with aromatic, bond angle or bond length alternated geometry. Highly accurate quantum Monte Carlo results indicate the existence of a crossover between C_10 and C_14 from bond angle to bond length alternation. The aromatic isomer is always a transition state. The driving mec...

  20. Insect-inspired wing actuation structures based on ring-type resonators

    Bolsman, C.T.; Goosen, J.F.L.; Van Keulen, F.

    2008-01-01

    In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of inspiration for the development of the wing actuation mechanisms for flapping wing MAVs. The insect thorax is a structure which in essence provides a mechanism to couple the wing muscles to the wi...

  1. General vibration monitoring: Coupling between the experimental hall structure and storage ring tunnel and basemat

    The primary objective of this study was to measure the coupling between the experimental hall structure and the storage ring tunnel. The study was motivated in part by concern over the potential for wind excitation of the building to couple through the ground and/or piping/ductwork to the storage ring basemat. Unfortunately, there was very little wind on the measurement date. However, it can be assumed that the wind turbulence would excite the experimental hall structure at one or more of its resonant frequencies. Similar coupling information can be obtained by using ambient vibration as the excitation source and measuring the resultant structure/basemat response and associated coupling. This was the approach taken in this study

  2. A new glass GEM with a single-sided guard-ring structure

    The gas electron multiplier (GEM) is a gaseous detector that is widely used in many applications. Our glass GEM (G-GEM) comprises a photo-etchable glass (PEG3, HOYA Corporation, Japan). Our research indicated that it shows superior performance compared with other gas detectors. In this article, a new type of G-GEM is introduced. It has a guard-ring structure around the holes in order to improve the spark tolerance by reducing the total capacitance of each hole structure. A measured gas gain of approximately 7500 is attained for this new G-GEM with a single-sided guard-ring structure using a gas mixture of Ar (90%) and CH4 (10%) in the gas flow mode. An energy resolution of 17.3% (FWHM) is also achieved with a collimated 6 keV X-ray beam. The results of a 10 to 12 hour gas gain stability measurements are also shown. (author)

  3. Correlation between magnetic spin structure and the three-dimensional geometry in chemically synthesized nanoscale magnetite rings

    Eltschka, M.; Klaui, M.; Rudiger, U;

    2008-01-01

    The correlation between magnetic spin structure and geometry in nanoscale chemically synthesized Fe3O4 rings has been investigated by transmission electron microscopy. We find primarily the flux closure vortex states but in rings with thickness variations, an effective stray field occurs. Using t...... interaction between exchange coupled rings leads to antiparallel vortex states and extended onion states. (c) 2008 American Institute of Physics....

  4. Time structure measurement of the SSRF storage ring using TRXEOL method

    张招红; 姜政; 薛松; 郑丽芳

    2015-01-01

    In order to do alignment between the timing signal and the synchrotron X-ray pulse on the sample spot in the time domain, measuring time structure of the storage ring on the sample spot inside the experimental hutch is a foundational step during the time-resolved experiments using the pulsed synchrotron X-rays with the time structure defined by the storage ring. In this work, the method of time-resolved X-ray excited optical luminescence (TRXEOL) was designed and implemented to do the measurement. It is based on the principle of time-correlated single photon counting techniques. The measurement system consists of a spectrometer with a detector of photomultiplier tube, a timing system, a set of nuclear instrument modules and a luminescent material of zinc oxide. The measurement was performed on the X-ray absorbed fine structure spectrum beamline at Shanghai Synchrotron Radiation Facility. The results show that this method can be used to measure the time structure of the storage ring with a precision of less than 1 ns. The measurement system can also be used for the time-resolved research for the optical luminescent materials.

  5. Asymmetric ring structure of Vps4 required for ESCRT-III disassembly

    Caillat, Christophe; Macheboeuf, Pauline; Wu, Yuanfei; McCarthy, Andrew A.; Boeri-Erba, Elisabetta; Effantin, Gregory; Göttlinger, Heinrich G.; Weissenhorn, Winfried; Renesto, Patricia

    2015-12-01

    The vacuolar protein sorting 4 AAA-ATPase (Vps4) recycles endosomal sorting complexes required for transport (ESCRT-III) polymers from cellular membranes. Here we present a 3.6-Å X-ray structure of ring-shaped Vps4 from Metallosphera sedula (MsVps4), seen as an asymmetric pseudohexamer. Conserved key interface residues are shown to be important for MsVps4 assembly, ATPase activity in vitro, ESCRT-III disassembly in vitro and HIV-1 budding. ADP binding leads to conformational changes within the protomer, which might propagate within the ring structure. All ATP-binding sites are accessible and the pseudohexamer binds six ATP with micromolar affinity in vitro. In contrast, ADP occupies one high-affinity and five low-affinity binding sites in vitro, consistent with conformational asymmetry induced on ATP hydrolysis. The structure represents a snapshot of an assembled Vps4 conformation and provides insight into the molecular motions the ring structure undergoes in a concerted action to couple ATP hydrolysis to ESCRT-III substrate disassembly.

  6. Electronic structures of GaAs/AlxGa1-xAs quantum double rings

    Li Shu-Shen

    2006-01-01

    Full Text Available AbstractIn the framework of effective mass envelope function theory, the electronic structures of GaAs/AlxGa1-xAs quantum double rings (QDRs are studied. Our model can be used to calculate the electronic structures of quantum wells, wires, dots, and the single ring. In calculations, the effects due to the different effective masses of electrons and holes in GaAs and AlxGa1-xAs and the valence band mixing are considered. The energy levels of electrons and holes are calculated for different shapes of QDRs. The calculated results are useful in designing and fabricating the interrelated photoelectric devices. The single electron states presented here are useful for the study of the electron correlations and the effects of magnetic fields in QDRs.

  7. On the structure of Witt-Burnside rings attached to pro-p groups

    Miller, Lance Edward

    2011-01-01

    The classical Witt vectors are a ubiquitous object in algebra and number theory. They arise as a functorial construction that takes perfect fields k of prime characteristic p > 0 to p-adically complete discrete valuation rings of characteristic 0 with residue field k and are universal in that sense. A. Dress and C. Siebeneicher generalized this construction by producing a functor W_G attached to any profinite group G. The classical Witt vectors are those attached to the p-adic integers. Here we examine the ring structure of W_G(k) for several examples of pro-p groups G and fields k of characteristic p. We will show that the structure is surprisingly more complicated than the classical case.

  8. The complete structure of the cohomology ring and associated symmetries in D = 2 string theory

    We determine explicitly all structure constants of the whole chiral BRST cohomology ring in D=2 string theory including both the discrete states and tachyon states. This is made possible by establishing several identities for Schur polynomials with operator argument and exploring associativity. Furthermore we find that the (chiral) symmetry algebra of the charges obtained by using the descent equations can actually be read off from the cohomology ring structure by simple operation involving the ghost field b. We also determine the enlarged symmetry algebra which contains the charges having ghost number -1 and 1. Finally the complete symmetry transformation rules are derived for closed string discrete states by carefully combining the left and right sectors. It turns out that the new states introduced recently by Witten and Zwiebach are naturally created when symmetries act on the old states. (orig.)

  9. P-clean rings

    Weixing Chen

    2006-01-01

    In this paper we unify the structures of various clean rings by introducing the notion of P-clean rings. Some properties of P-clean rings are investigated, which generalize the known results on clean rings, semiclean rings, n-clean rings, and so forth. By the way, we answer a question of Xiao and Tong on n-clean rings in the negative.

  10. Diffusion Flame Structure of a Vortex Ring under μg Conditions

    Chen, Shin-Juh; Dahm, Werner J. A.

    1996-11-01

    Experimental results are presented for the structure of a gaseous diffusion flame formed when a vortex ring of various fuel compositions burns in air under normal gravity and under microgravity conditions. The experiment provides a canonical representation of vortex-diffusion flame interactions in turbulent reacting flows, and is closely related to the earlier vortex pair analysis of Karagozian & Manda (1986) and Manda & Karagozian (1988). Experimental conditions allow the competing hydrodynamic and chemical time scales to span from the near-equilibrium mixing-chemistry coupling regime to the deep-nonequilibrium regime. Microgravity experiments were conducted in the NASA LeRC 2.2 sec drop tower, for which the hydrostatic contribution to baroclininc generation is suppressed. Results extend from the initial ring formation time through the consumption of the entire fuel in the ring or through strain-out of the reaction process. These show interactions of the reaction zones during rollup of the ring, as well as strained flame phenomena at the forward stagnation point, providing a controlled environment for studying a wide range of vortex-diffusion flame interactions. (Supported by NASA Grant No. NAG-1639.)

  11. Omnidirectional piezo-optical ring sensor for enhanced guided wave structural health monitoring

    This paper presents a novel method for the detection of ultrasonic waves from acoustic emission events using piezoelectric wafer ac3tive sensors (PWAS) and optical fiber Bragg grating (FBG) sensing combined with mechanical resonance amplification principles. The method is best suited for detecting the out-of-plane motion of the AE wave with preference for a certain frequency that can be adjusted by design. Several issues are discussed: (a) study the mode shapes of the sensors under different resonance frequencies in order to understand the behavior of the ring in a frequency band of interest; (b) comparison of analytical results and mode shapes with FEM predictions; (c) choice of the final piezo-optical ring sensor shape; (d) testing of the piezo-optical ring sensor prototype; (e) discussion of the ring-sensor test results in comparison with conventional results from PWAS and FBG sensors mounted directly on the test structure. The paper ends with summary, conclusions, and suggestions for further work. (paper)

  12. Structure of a RING E3 ligase and ubiquitin-loaded E2 primed for catalysis.

    Plechanovová, Anna; Jaffray, Ellis G; Tatham, Michael H; Naismith, James H; Hay, Ronald T

    2012-09-01

    Ubiquitin modification is mediated by a large family of specificity determining ubiquitin E3 ligases. To facilitate ubiquitin transfer, RING E3 ligases bind both substrate and a ubiquitin E2 conjugating enzyme linked to ubiquitin via a thioester bond, but the mechanism of transfer has remained elusive. Here we report the crystal structure of the dimeric RING domain of rat RNF4 in complex with E2 (UbcH5A) linked by an isopeptide bond to ubiquitin. While the E2 contacts a single protomer of the RING, ubiquitin is folded back onto the E2 by contacts from both RING protomers. The carboxy-terminal tail of ubiquitin is locked into an active site groove on the E2 by an intricate network of interactions, resulting in changes at the E2 active site. This arrangement is primed for catalysis as it can deprotonate the incoming substrate lysine residue and stabilize the consequent tetrahedral transition-state intermediate. PMID:22842904

  13. Formation of irregular rings in silica aerogel structure during the sintering process

    Hinić Ivana I.

    2003-01-01

    Full Text Available Samples of low-density, highly disordered silica aerogel with initial bulk density of 0.16 g/cm3, were sintered isothermally in different time intervals at 1000ºC. Structural changes during the sintering process have been investigated by Raman spectroscopy. Defect modes of irregular three and four membered rings were observed in the Raman spectra of sintered samples.

  14. Design summary of the magnet support structures for the proton storage ring injection line upgrade

    This report summarizes the technical engineering and design issues associated with the Proton Storage Ring (PSR) Injection Line upgrade of the Los Alamos Neutron Science Center (LANSCE). The main focus is on the engineering design calculations of several magnet support structures. The general procedure based upon a set number of design criteria is outlined, followed by a case-by-case summary of the engineering design analyses, reutilization or fabrication callouts and design safety factors

  15. Fiber amplifiers, directly modulated transmitters and a ring network structure for optical communications

    Tammela, Simo

    2004-01-01

    The three technologies that are considered the key elements in building a metropolitan area optical network are studied in this thesis. They are optical amplification, high-speed low cost transmitters and ring network structures. These studies concentrate on cost reduction of these three technologies thus enabling the use of optical networks in small customer base metropolitan areas. The research on optical amplification concentrated first on the solution doping process, at present the mo...

  16. A hetero-structured ring discovered by CAS nano-scientists

    2007-01-01

    @@ Teaming up with co-workers,researchers from the CAS-affiliated National Center for Nanoscience and Technology(NCNST) recently succeeded in fabricating a hetero-structured nano-ring in their laboratory. The feat, scientist believe, would be valuable for developing new optical or electronic nano-elements and related devices in the near future.The work was recently reported by Advanced Materials (Vol. 19, 2319-2323, 2007).

  17. Structural and thermodynamic aspects of the dissociation of cyclopentadienyl rings from homoleptic cyclopentadienyl early transition metal, cerium, and thorium derivatives

    Graphical abstract: Density functional theory indicates that for Cp4M the S4 structures are saddle points and the minima have C1 symmetry with all η5-Cp rings for M = Ce and Th, three η5-Cp rings and one η5-Cp ring for M = Zr, and two η5-Cp rings and two η5-Cp rings for M = Ti and Hf. The dissociation energies for Cp4M → Cp3M + Cp· increase in the sequence Ti 3h structures with all η5-Cp rings are genuine minima for most of the Cp3M compounds except for Cp3Ti, which has a Cs symmetry minimum with two η5-Cp rings and one η2-Cp ring. The dissociation energies for Cp3M → Cp2M + Cp· increase in the sequence V 4M the S4 structures are saddle points. → The minima for Cp4M have all η5-Cp rings for M = Ce and Th, three η5-Cp rings and one η1-Cp ring for M = Zr, and two η5-Cp rings and two η5-Cp rings for M = Ti and Hf. → The dissociation energies for Cp4M → Cp3M + Cp· increase in the sequence Ti 3h structures with all η5-Cp rings are genuine minima for all of the Cp3M compounds except for Cp3Ti. → The dissociation energies for Cp3M → Cp2M + Cp· increase in the sequence V 4M (M = Ti, Zr, Ce, Hf, Th), Cp3M (M = Sc, Y, most lanthanides, Ti, Zr, Hf, Th), and Cp2M (M = Ti, V). Density functional theory shows that the Cp4M structures with unusual S4 symmetry are saddle points for the d-block metals Ti, Zr, Hf but genuine minima for the f-block metals Ce and Th. The true equilibrium Cp4M geometries have C1 symmetry with two η5-Cp rings and two η1-Cp rings for M = Ti and Hf but three η5-Cp rings and one η1-Cp ring for M = Zr. The dissociation energies for Cp4M → Cp3M + Cp· are substantial and in the order Ti 3h structures with all η5-Cp rings are genuine minima for most of the Cp3M compounds except for Cp3Ti, which has a Cs symmetry minimum with two η5-Cp rings and one η2-Cp ring, and Cp3V, which has two η5-Cp rings and one η1-Cp ring. The dissociation energies for Cp3M → Cp2M + Cp· are in the order V < Ti < Sc < Y < La, consistent

  18. Structural basis for the RING catalyzed synthesis of K63 linked ubiquitin chains

    Branigan, Emma; Plechanovová, Anna; Jaffray, Ellis; Naismith, James H.; Hay, Ronald T.

    2015-01-01

    The RING E3 ligase catalysed formation of lysine 63 linked ubiquitin chains by the Ube2V2–Ubc13 E2 complex is required for many important biological processes. Here we report the structure of the RING domain dimer of rat RNF4 in complex with a human Ubc13~Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with Lys63 in a position that could lead to attack on the linkage between the donor (second) ubiquitin and Ubc13 that is held in the active “folded back” conformation by the RING domain of RNF4. The interfaces identified in the structure were verified by in vitro ubiquitination assays of site directed mutants. This represents the first view of the synthesis of Lys63 linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase mediated catalysis. PMID:26148049

  19. Structural basis for the RING-catalyzed synthesis of K63-linked ubiquitin chains.

    Branigan, Emma; Plechanovová, Anna; Jaffray, Ellis G; Naismith, James H; Hay, Ronald T

    2015-08-01

    RING E3 ligase-catalyzed formation of K63-linked ubiquitin chains by the Ube2V2-Ubc13 E2 complex is required in many important biological processes. Here we report the structure of the RING-domain dimer of rat RNF4 in complex with a human Ubc13∼Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with K63 in a position favorable for attack on the linkage between Ubc13 and the donor (second) ubiquitin held in the active 'folded back' conformation by the RING domain of RNF4. We verified the interfaces identified in the structure by in vitro ubiquitination assays of site-directed mutants. To our knowledge, this represents the first view of synthesis of K63-linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase-mediated catalysis. PMID:26148049

  20. General vibration monitoring: Coupling between a storage ring tunnel I-beam support structure and the tunnel/basemat

    The primary objective of this study was to measure the coupling between a specific I-beam support structure, cantilevered from the infield side of the storage ring tunnel, and the storage ring tunnel/basemat. The support structure is mechanically connected to the side of the tunnel. It has the potential for a large resonant response and coupling to the storage ring basemat through its mechanical mounting or through the many pipes and ducts fastened to it. Impact excitation force was used to determine the lowest resonant frequency of the structure. Ambient vibration was used as the excitation source for studying the coupling

  1. Repression of the Escherichia coli modABCD (molybdate transport) operon by ModE.

    Grunden, A M; Ray, R M; Rosentel, J K; Healy, F. G.; Shanmugam, K. T.

    1996-01-01

    The modABC gene products constitute the molybdate-specific transport system in Escherichia coli. Another operon coding for two proteins which diverges from the modABCD operon has been identified. The first gene of this operon codes for a 262-amino-acid protein, designated ModE (28 kDa), and the second genes codes for a 490-amino-acid protein. ModF (54 kDa). The role of ModF has not yet been determined; however, mutations in modE depressed modABCD transcription even in the presence of molybdat...

  2. Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

    2008-01-01

    By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.

  3. Development and validation of a three-dimensional ring-based structural tyre model

    Kindt, P.; Sas, P.; Desmet, W.

    2009-10-01

    This paper presents a structural model for an unloaded tyre, based on a three-dimensional flexible ring on an elastic foundation. The ring represents the belt and the elastic foundation represents the tyre sidewall. The model is valid up to 300 Hz and includes a submodel of the wheel and the air cavity. This makes the model potentially suitable for the prediction of structure-borne interior noise. Unlike most ring models, which only consider in-plane modes, the presented model also predicts the modes that involve torsion of the belt in circumferential direction. The parameterization of the model, which does not require detailed knowledge of the tyre construction, is based on the main geometrical properties of the tyre and a limited modal test. Comparison between measured and calculated responses shows that the tyre-wheel model describes the dynamic behaviour with acceptable accuracy. Since the model is physical, it can be applied to describe other operational conditions such as loading and rotation.

  4. Remote sensing observations of the coherent and non-coherent ring structures in the vicinity of Lesser Antilles

    R. C. Cruz Gómez

    2007-03-01

    Full Text Available The North Brazil Current Rings (NBCR penetration into the Caribbean Sea is being investigated by employing a merged altimeter-derived sea height anomaly (TOPEX/Poseidon, Jason-1 and ERS-1, 2, the ocean surface color data (SeaWiFS and Global Drifter Program information. Four strategies are being applied to process the data: (1 calculations of the Okubo-Weiss parameter for NBCR identification, (2 longitude-time plots (also known as Hovmöller diagrams, (3 two-dimensional Radon transforms and (4 two-dimensional Fourier transforms.

    A twofold NBCR structure has been detected in the region under investigation. The results have shown that NBC rings mainly propagate into the Caribbean Sea along two principal pathways (near 12° N and 17° N in the ring translation corridor. Thus, rings following the southern pathway in the fall-winter period can enter through very shallow southern straits as non-coherent structures. A different behavior is observed near the northern pathway (~17° N, where NBC rings are thought to have a coherent structure during their squeezing into the eastern Caribbean, i.e. conserving the principal characteristics of the incident rings. We attribute this difference in the rings' behavior to the vertical scales of the rings and to the bottom topography features in the vicinity of the Lesser Antilles.

  5. Structural transition in inactive Balbiani ring chromatin of Chironomus during micrococcus nuclease digestion

    Widmer, R. M.; Lezzi, M.; Koller, Th.

    1987-01-01

    We have analysed by micrococcus nuclease digestion the chromatin structure of genes in the Balbiani ring (BR) regions of a Chironomus cell line. Gel electrophoresis of the DNA fragments reveals a repeating structure which consists of two repeat sizes, a long repeat seen in the large fragments and a small repeat seen in the small fragments. The two repeats hardly overlap, except in a narrow transition zone which is at a different fragment size in the BR 2.2 and the BR 2.1 gene. The sizes of th...

  6. ZnO-coated SMS structure interrogated by a fiber ring laser for chemical sensing

    Wen, X. Y.; Huang, J.; Xiao, H.; Yang, M. H.

    2014-11-01

    A zinc oxide (ZnO)-coated single mode-multimode-single mode fiber (SMS) structure interrogated by a fiber ring laser has been developed as a chemical sensor. Response to relative humidity (RH) and ethanol volatilization was evaluated by tracking the wavelength shifts of the output laser line in different moisture environments and ethanol solutions, respectively. For humidity sensing a linear response with a measurement range of 4-96% RH, and a sensitivity of 0.06 nm per %RH were obtained. As for ethanol volatilization sensing obvious wavelength blue shift was observed for the sensor immersed in 50% and 62% ethanol solution, while no variation could be detected in pure ethanol solution (purity larger than 97%). With the advantages of low cost, ease of fabrication and sensitive response, ZnO-coated SMS interrogated with a fiber ring laser was demonstrated to be an effective sensor for humidity and ethanol volatilization sensing.

  7. ZnO-coated SMS structure interrogated by a fiber ring laser for chemical sensing

    A zinc oxide (ZnO)-coated single mode–multimode–single mode fiber (SMS) structure interrogated by a fiber ring laser has been developed as a chemical sensor. Response to relative humidity (RH) and ethanol volatilization was evaluated by tracking the wavelength shifts of the output laser line in different moisture environments and ethanol solutions, respectively. For humidity sensing a linear response with a measurement range of 4–96% RH, and a sensitivity of 0.06 nm per %RH were obtained. As for ethanol volatilization sensing obvious wavelength blue shift was observed for the sensor immersed in 50% and 62% ethanol solution, while no variation could be detected in pure ethanol solution (purity larger than 97%). With the advantages of low cost, ease of fabrication and sensitive response, ZnO-coated SMS interrogated with a fiber ring laser was demonstrated to be an effective sensor for humidity and ethanol volatilization sensing. (paper)

  8. Multi-cell disk-and-ring tapered structure for compact RF linacs

    Smirnov, A. V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

    2016-09-01

    A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

  9. Gaps, rings, and non-axisymmetric structures in protoplanetary disks: Emission from large grains

    Ruge, J. P.; Flock, M.; Wolf, S.; Dzyurkevich, N.; Fromang, S.; Henning, Th.; Klahr, H.; Meheut, H.

    2016-04-01

    Aims: Dust grains with sizes around (sub)mm are expected to couple only weakly to the gas motion in regions beyond 10 au of circumstellar disks. In this work, we investigate the influence of the spatial distribution of these grains on the (sub)mm appearance of magnetized protoplanetary disks. Methods: We perform non-ideal global 3D magneto-hydrodynamic (MHD) stratified disk simulations, including particles of different sizes (50 μm to 1 cm), using a Lagrangian particle solver. Subsequently, we calculate the spatial dust temperature distribution, including the dynamically coupled submicron-sized dust grains, and derive ideal continuum re-emission maps of the disk through radiative transfer simulations. Finally, we investigate the feasibility of observing specific structures in the thermal re-emission maps with the Atacama Large Millimeter/submillimeter Array (ALMA). Results: Depending on the level of turbulence, the radial pressure gradient of the gas, and the grain size, particles settle to the midplane and/or drift radially inward. The pressure bump close to the outer edge of the dead-zone leads to particle-trapping in ring structures. More specifically, vortices in the disk concentrate the dust and create an inhomogeneous distribution of solid material in the azimuthal direction. The large-scale disk perturbations are preserved in the (sub)mm re-emission maps. The observable structures are very similar to those expected from planet-disk interaction. Additionally, the larger dust particles increase the brightness contrast between the gap and ring structures. We find that rings, gaps, and the dust accumulation in the vortex could be traced with ALMA down to a scale of a few astronomical units in circumstellar disks located in nearby star-forming regions. Finally, we present a brief comparison of these structures with those recently found with ALMA in the young circumstellar disks of HL Tau and Oph IRS 48.

  10. ABCD2 identifies a subclass of peroxisomes in mouse adipose tissue

    Highlights: • We examined the D2 localization and the proteome of D2-containing compartment in mouse adipose tissue. • We confirmed the presence of D2 on a subcellular compartment that has typical structure as a microperoxisome. • We demonstrated the scarcity of peroxisome markers on D2-containing compartment. • The D2-containing compartment may be a subpopulation of peroxisome in mouse adipose tissue. • Proteomic data suggests potential association between D2-containing compartment and mitochondria and ER. - Abstract: ATP-binding cassette transporter D2 (D2) is an ABC half transporter that is thought to promote the transport of very long-chain fatty acyl-CoAs into peroxisomes. Both D2 and peroxisomes increase during adipogenesis. Although peroxisomes are essential to both catabolic and anabolic lipid metabolism, their function, and that of D2, in adipose tissues remain largely unknown. Here, we investigated the D2 localization and the proteome of D2-containing organelles, in adipose tissue. Centrifugation of mouse adipose homogenates generated a fraction enriched with D2, but deficient in peroxisome markers including catalase, PEX19, and ABCD3 (D3). Electron microscopic imaging of this fraction confirmed the presence of D2 protein on an organelle with a dense matrix and a diameter of ∼200 nm, the typical structure and size of a microperoxisome. D2 and PEX19 antibodies recognized distinct structures in mouse adipose. Immunoisolation of the D2-containing compartment confirmed the scarcity of PEX19 and proteomic profiling revealed the presence of proteins associated with peroxisome, endoplasmic reticulum (ER), and mitochondria. D2 is localized to a distinct class of peroxisomes that lack many peroxisome proteins, and may associate physically with mitochondria and the ER

  11. ABCD2 identifies a subclass of peroxisomes in mouse adipose tissue

    Liu, Xiaoxi, E-mail: xiaoxi.liu@uky.edu; Liu, Jingjing, E-mail: jingjing.liu0@gmail.com; Lester, Joshua D., E-mail: joshua.lester@uky.edu; Pijut, Sonja S., E-mail: srhee2@uky.edu; Graf, Gregory A., E-mail: Gregory.Graf@uky.edu

    2015-01-02

    Highlights: • We examined the D2 localization and the proteome of D2-containing compartment in mouse adipose tissue. • We confirmed the presence of D2 on a subcellular compartment that has typical structure as a microperoxisome. • We demonstrated the scarcity of peroxisome markers on D2-containing compartment. • The D2-containing compartment may be a subpopulation of peroxisome in mouse adipose tissue. • Proteomic data suggests potential association between D2-containing compartment and mitochondria and ER. - Abstract: ATP-binding cassette transporter D2 (D2) is an ABC half transporter that is thought to promote the transport of very long-chain fatty acyl-CoAs into peroxisomes. Both D2 and peroxisomes increase during adipogenesis. Although peroxisomes are essential to both catabolic and anabolic lipid metabolism, their function, and that of D2, in adipose tissues remain largely unknown. Here, we investigated the D2 localization and the proteome of D2-containing organelles, in adipose tissue. Centrifugation of mouse adipose homogenates generated a fraction enriched with D2, but deficient in peroxisome markers including catalase, PEX19, and ABCD3 (D3). Electron microscopic imaging of this fraction confirmed the presence of D2 protein on an organelle with a dense matrix and a diameter of ∼200 nm, the typical structure and size of a microperoxisome. D2 and PEX19 antibodies recognized distinct structures in mouse adipose. Immunoisolation of the D2-containing compartment confirmed the scarcity of PEX19 and proteomic profiling revealed the presence of proteins associated with peroxisome, endoplasmic reticulum (ER), and mitochondria. D2 is localized to a distinct class of peroxisomes that lack many peroxisome proteins, and may associate physically with mitochondria and the ER.

  12. Abundances and density structure of the inner circumstellar ring around SN 1987A

    Mattila, Seppo; Groeningsson, Per; Meikle, Peter; Stathakis, Raylee; Fransson, Claes; Cannon, Russell

    2010-01-01

    We present optical spectroscopic data of the inner circumstellar ring around SN 1987A from the Anglo-Australian Telescope (AAT) and the Very Large Telescope (VLT) between ~1400 and ~5000 days post-explosion. We also assembled the available optical and near-infrared line fluxes from the literature between ~300 and ~2000 days. These line light curves were fitted with a photoionization model to determine the density structure and the elemental abundances for the inner ring. We found densities ranging from 1x10^3 to 3x10^4 atoms cm^-3 and a total mass of the ionized gas of 0.058 Msun within the inner ring. Abundances inferred from the optical and near-infrared data were also complemented with estimates of Lundqvist & Fransson (1996) based on ultraviolet lines. This way we found an He/H-ratio (by number of atoms) of 0.17+-0.06, N/O-ratio of 1.5+-0.7, and the total (C+N+O)/(H+He) abundance about 1.6 times its LMC value or roughly 0.6 times the most recent solar value. An iron abundance of 0.20+-0.11 times solar...

  13. Reusable Solid Rocket Motor - V(RSRMV)Nozzle Forward Nose Ring Thermo-Structural Modeling

    Clayton, J. Louie

    2012-01-01

    During the developmental static fire program for NASAs Reusable Solid Rocket Motor-V (RSRMV), an anomalous erosion condition appeared on the nozzle Carbon Cloth Phenolic nose ring that had not been observed in the space shuttle RSRM program. There were regions of augmented erosion located on the bottom of the forward nose ring (FNR) that measured nine tenths of an inch deeper than the surrounding material. Estimates of heating conditions for the RSRMV nozzle based on limited char and erosion data indicate that the total heat loading into the FNR, for the new five segment motor, is about 40-50% higher than the baseline shuttle RSRM nozzle FNR. Fault tree analysis of the augmented erosion condition has lead to a focus on a thermomechanical response of the material that is outside the existing experience base of shuttle CCP materials for this application. This paper provides a sensitivity study of the CCP material thermo-structural response subject to the design constraints and heating conditions unique to the RSRMV Forward Nose Ring application. Modeling techniques are based on 1-D thermal and porous media calculations where in-depth interlaminar loading conditions are calculated and compared to known capabilities at elevated temperatures. Parameters such as heat rate, in-depth pressures and temperature, degree of char, associated with initiation of the mechanical removal process are quantified and compared to a baseline thermo-chemical material removal mode. Conclusions regarding postulated material loss mechanisms are offered.

  14. Initial assessment and treatment with the Airway, Breathing, Circulation, Disability, Exposure (ABCDE approach

    Thim T

    2012-01-01

    Full Text Available Troels Thim1,2, Niels Henrik Vinther Krarup1,4, Erik Lerkevang Grove1, Claus Valter Rohde3, Bo Løfgren1,41Department of Cardiology, Aarhus University Hospital, Aarhus, 2Department of Internal Medicine, Regional Hospital of Randers, Randers, 3Department of Anestesiology, Aarhus University Hospital, Aarhus, 4Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, DenmarkAbstract: The Airway, Breathing, Circulation, Disability, Exposure (ABCDE approach is applicable in all clinical emergencies for immediate assessment and treatment. The approach is widely accepted by experts in emergency medicine and likely improves outcomes by helping health care professionals focusing on the most life-threatening clinical problems. In an acute setting, high-quality ABCDE skills among all treating team members can save valuable time and improve team performance. Dissemination of knowledge and skills related to the ABCDE approach are therefore needed. This paper offers a practical “how-to” description of the ABCDE approach.Keywords: emergency medicine, general medicine, internal medicine, multiple trauma, multiple injury

  15. ABCD syndrome is caused by a homozygous mutation in the EDNRB gene

    Verheij, JBGM; Kunze, J; Osinga, J; van Essen, AJ; Hofstra, RMW

    2002-01-01

    ABCD syndrome is an autosomal recessive syndrome characterized by albinism, black lock, cell migration disorder of the neurocytes of the gut (Hirschsprung disease [HSCR]), and deafness. This phenotype clearly overlaps with the features of the Shah-Waardenburg syndrome, comprising sensorineural deafn

  16. Special Features of the Advanced Loans Module of the ABCD Integrated Library System

    de Smet, Egbert

    2011-01-01

    Purpose: The "advanced loans" module of the relatively new library software, ABCD, is an addition to the normal loans module and it offers a "generic transaction decision-making engine" functionality. The module requires extra installation effort and parameterisation, so this article aims to explain to the many potentially interested libraries,…

  17. Application of ABCD Formalism in Theoretical and Experimental Analysis of Actively Modelocked Fiber Laser

    2002-01-01

    Time domain ABCD matrix formalism is a useful model for analyzing the characteristics of actively modelocked fiber laser. Based on this model and given more consideration on the influences of optical fiber dispersion and optical fiber nonlinearity, the laser characteristic of actively modelocked fiber laser is analyzed, and the comparision of the theoretical analysis results with experimental ones is given.

  18. Locally finite profinite rings

    Dobrowolski, Jan; Krupiński, Krzysztof

    2013-01-01

    We investigate the structure of locally finite profinite rings. We classify (Jacobson-) semisimple locally finite profinite rings as products of complete matrix rings of bounded cardinality over finite fields, and we prove that the Jacobson radical of any locally finite profinite ring is nil of finite nilexponent. Our results apply to the context of small compact $G$-rings, where we also obtain a description of possible actions of $G$ on the underlying ring.

  19. Brain microsomal fatty acid elongation is increased in abcd1-deficient mouse during active myelination phase.

    Morita, Masashi; Kawamichi, Misato; Shimura, Yusuke; Kawaguchi, Kosuke; Watanabe, Shiro; Imanaka, Tsuneo

    2015-12-01

    The dysfunction of ABCD1, a peroxisomal ABC protein, leads to the perturbation of very long chain fatty acid (VLCFA) metabolism and is the cause of X-linked adrenoleukodystrophy. Abcd1-deficient mice exhibit an accumulation of saturated VLCFAs, such as C26:0, in all tissues, especially the brain. The present study sought to measure microsomal fatty acid elongation activity in the brain of wild-type (WT) and abcd1-deficient mice during the course of development. The fatty acid elongation activity in the microsomal fraction was measured by the incorporation of [2-(14)C]malonyl-CoA into fatty acids in the presence of C16:0-CoA or C20:0-CoA. Cytosolic fatty acid synthesis activity was completely inhibited by the addition of N-ethylmaleimide (NEM). The microsomal fatty acid elongation activity in the brain was significantly high at 3 weeks after birth and decreased substantially at 3 months after birth. Furthermore, we detected two different types of microsomal fatty acid elongation activity by using C16:0-CoA or C20:0-CoA as the substrate and found the activity toward C20:0-CoA in abcd1-deficient mice was higher than the WT 3-week-old animals. These results suggest that during the active myelination phase the microsomal fatty acid elongation activity is stimulated in abcd1-deficient mice, which in turn perturbs the lipid composition in myelin. PMID:26108493

  20. Axial block coordinate descent (ABCD) algorithm for X-ray CT image reconstruction

    The primary drawback of statistical image reconstruction methods for X-ray CT is the computation time required by iterative algorithms. Iterative coordinate descent (ICD) algorithms converge in relatively few iterations but are challenging to parallelize due to their sequential updates. Conjugate gradient (CG) methods and ordered-subsets (OS) algorithms update all pixels simultaneously, which facilitates parallelization, but these algorithms require many more iterations to converge than ICD. This paper proposes a block coordinate descent algorithm for helical and axial cone-beam X-ray CT image reconstruction in which a group of voxels are updated simultaneously. We focus on updating all the voxels within one axial 'column' of the 3D image simultaneously, so we refer to this approach as the axial block coordinate descent (ABCD) algorithm. Because this approach updates many voxels simultaneously (e.g., 64 in an axial scan and hundreds in a helical scan), it is reasonably well suited to parallel processing. At the same time, because the voxels within an axial column are relatively weakly coupled, which is why we selected axial blocks, the algorithm converges fairly quickly. In particular, the simultaneous update of one axial column requires inverting a banded matrix which can be done quickly (ABCD-BAND). An alternative version of the algorithm uses a simpler separable quadratic surrogate for the axial block (ABCD-SQS). Preliminary simulation results illustrate that the ABCD algorithms decrease a regularized weighted least-squares cost function much faster than a traditional separable quadratic surrogate (SQS) method that updates all pixels simultaneously. The proposed ABCD algorithms exhibit about the same decrease per iteration as the ICD method, while appearing much more amenable to parallelization. (orig.)

  1. Synthesis, insecticidal activity, and structure-activity relationship (SAR) of anthranilic diamides analogs containing oxadiazole rings.

    Li, Yuhao; Zhu, Hongjun; Chen, Kai; Liu, Rui; Khallaf, Abdalla; Zhang, Xiangning; Ni, Jueping

    2013-06-28

    A series of anthranilic diamides analogs (3–11, 16–24) containing 1,2,4- or 1,3,4-oxadiazole rings were synthesized and characterized by (1)H NMR, MS and elemental analyses. The structure of 3-bromo-N-(2-(3-(4-bromophenyl)-1,2,4-oxadiazol-5-yl)-4-chloro-6-methylphenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide (18, CCDC-) was determined by X-ray diffraction crystallography. The insecticidal activities against Plutella xylostella and Spodoptera exigua were evaluated. The results showed that most of title compounds displayed good larvicidal activities against P. xylostella, especially compound 3-bromo-N-(4-chloro-2-methyl-6-(5-(methylthio)-1,3,4-oxadiazol-2-yl)phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide (6), which displayed 71.43% activity against P. xylostella at 0.4 μg mL(-1) and 33.33% against S. exigua at 1 μg mL(-1). The structure-activity relationship showed that compounds decorated with a 1,3,4-oxadiazole were more potent than compounds decorated with a 1,2,4-oxadiazole, and different substituents attached to the oxadiazole ring also affected the insecticidal activity. This work provides some hints for further structure modification and the enhancement of insecticidal activity. PMID:23657615

  2. Community Structure of Urban Forest and Disposition Characteristics of Trees in Hefei Ring Park

    WUZemin; WANGYuan; ZHANGShaojie; YANGHaiyan; XUYinbi

    2004-01-01

    The methods of vegetation ecology were used to analyze the community structure of Hefei Ring Park, and species composition, distribution pattern of tree height and DBH were described. Through calculation of tree growth index and association correlation of component species, the community structures were analyzed. The results showed that community structures are complex, there are 22 pairs of species with positive association, and tree individual in the following communities grow well and are more stable, the major are Platycladus orientalis-Prunus cerasifera fatropurpurea-Osmanthus fragrans, Robinia pseduacacia-Ligustrum lucidum, Robinia pseudoacacia-Ginkgo biloba-Photinia serrulata, Populus cadadensis-Ligustrum lucidum-Osmanthus fragrans, Sophora japonica-Ligustrum lucidum-Buxus sinica, Cyclobalanopsis glauca-Distylium racemosum.

  3. Central ring structure identified in one of the world's best-preserved impact craters

    Gebhardt, A. C.; Niessen, F.; Kopsch, C.

    2006-03-01

    Seismic refraction and reflection data were acquired in 2000 and 2003 to study the morphology and sedimentary fill of the remote El'gygytgyn crater (Chukotka, northeastern Siberia; diameter 18 km). These data allow a first insight into the deeper structure of this unique impact crater. Wide-angle data from sonobuoys reveal a five-layer model: a water layer, two lacustrine sedimentary units that fill a bowl-shaped apparent crater morphology consisting of an upper layer of fallback breccia with P-wave velocities of ˜3000 m/s, and a lower layer of brecciated bedrock (velocities >3600 m/s). The lowermost layer shows a distinct anticline structure that, by analogy with other terrestrial and lunar craters of similar size, can be interpreted as a central ring structure. The El'gygytgyn crater exhibits a well-expressed morphology that is typical of craters formed in crystalline target rocks.

  4. A new level-shifting structure with multiply metal rings by divided RESURF technique

    Liu Jizhi; Chen Xingbi

    2009-01-01

    A new structure of a lateral n-MOST and a new level-shifting structure with multiply metal rings(MMRs) by divided RESURF technique have been proposed.The device and electrical performances of the structure are analyzed and simulated by MEDICI.In comparison to the level-shifting structure with multiply floating field plates (MFFPs)used before,the structure stated here improves the reliability and diminishes the voltage difference between the voltage of the power supply of the high-side gate driver and the voltage of the output terminal of the level-shifting structure,which is also that of the input terminal of the high-side gate driver.The maximal voltage difference of the level-shifting structure in this paper is 30%lower than that used before.Therefore,good voltage isolation and current isolation are obtained.The structure can be used in the level-shifting circuit of various applications.

  5. Voyager radio occultation by the Uranian rings: Structure, dynamics, and particle sizes. Ph.D. Thesis Final Technical Report

    Gresh, Donna Leigh

    1990-01-01

    Diffraction of Voyager 2's 3.6 and 13 cm wavelength microwaves by the Uranian rings is removed through an inverse Fresnel transform filtering procedure that accommodates the significant eccentricity of the rings. Resulting 50 m resolution profiles at two observation longitudes: (1) reveal remarkably detailed and longitudinally varying structure, (2) provide eccentricity gradient profiles of Rings alpha, beta, and epsilon which bring into question current theoretical models for observed rigid precession, and (3) suggest that two possible unseen satellites may confine some of the very sharp edges observed via resonant interactions.

  6. Crystal structure of the S. solfataricus archaeal exosome reveals conformational flexibility in the RNA-binding ring.

    Changrui Lu

    Full Text Available BACKGROUND: The exosome complex is an essential RNA 3'-end processing and degradation machinery. In archaeal organisms, the exosome consists of a catalytic ring and an RNA-binding ring, both of which were previously reported to assume three-fold symmetry. METHODOLOGY/PRINCIPAL FINDINGS: Here we report an asymmetric 2.9 A Sulfolobus solfataricus archaeal exosome structure in which the three-fold symmetry is broken due to combined rigid body and thermal motions mainly within the RNA-binding ring. Since increased conformational flexibility was also observed in the RNA-binding ring of the related bacterial PNPase, we speculate that this may reflect an evolutionarily conserved mechanism to accommodate diverse RNA substrates for degradation. CONCLUSION/SIGNIFICANCE: This study clearly shows the dynamic structures within the RNA-binding domains, which provides additional insights on mechanism of asymmetric RNA binding and processing.

  7. Radical theory of rings

    Gardner, JW

    2003-01-01

    Radical Theory of Rings distills the most noteworthy present-day theoretical topics, gives a unified account of the classical structure theorems for rings, and deepens understanding of key aspects of ring theory via ring and radical constructions. Assimilating radical theory's evolution in the decades since the last major work on rings and radicals was published, the authors deal with some distinctive features of the radical theory of nonassociative rings, associative rings with involution, and near-rings. Written in clear algebraic terms by globally acknowledged authorities, the presentation

  8. Rhombic Split Ring Resonator (R-SRR Structure on Rectangular Patch Antenna Design

    H. Nornikman

    2013-01-01

    Full Text Available This work focusing on the effect of the complementary rhombic split ring resonator (R-SRR structure of gain, return loss and the radiation pattern the rectangular patch antenna design. The basic rectangular patch antenna design had been simulated in CST Microwave Studio simulation software. Then, the single unit of the R-SRR had been added into the patch antenna design. The targeting frequency of this antenna is 2.40 GHz for Wireless Local Area Network (WLAN application. Compared with the conventional microstrip patch antenna with the same aperture size, the performance gain of the patch antennas is improved obviously and suitable for targeting frequency of 2.40 GHz. The parametric studies done this work work are the different variation pattern of R-SRR, different distance between two RSRR structure and different size of R-SRR.

  9. Moisture Management Behaviour of Knitted Fabric from Structurally Modified Ring and Vortex Spun Yarn

    Sharma, Navendu; Kumar, Pawan; Bhatia, Dinesh; Sinha, Sujit Kumar

    2015-11-01

    The acceptability of a new product is decided by its performance, level of improvement in quality and economy of production. The basic aim of generating micro pores in a textile structure is to provide better thermo-physiological comfort by enhancing the breathability and hence improving moisture management behaviour. In the present study, an attempt has been made to create a relatively more open structure through removal of a component. A comparative assessment with a homogeneous and parent yarn was also made. Yarns of two linear densities, each from ring and vortex spinning systems were produced using 100 % polyester and 80:20 polyester/cotton blend. The modified yarn was produced by removing a component, viz; cotton, by treatment with sulphuric acid from the blended yarn. The knitted fabric from modified yarn was found to show significant improvement in air permeability, water vapour permeability and total absorbency while the wicking characteristic was found to decline.

  10. Synthesis, Structure and Properties of Two Photochromic Compounds Containing A Pyrazolone-ring

    2000-01-01

    Two photochromic compounds with the pyrazolone-ring as the photochromic functional structure, 2-(1'-phenyl-3'-methyl-4'-benzoformyl-pyrazolone-5')-thiosemicarbazone(PMBP-TSC) and 2-(1'-phenyl-3'-methyl-4'-benzoformyl-pyrazolone-5')-S-methylthiosemicarbazone(PMBP-MTSC), were synthesized and characterized by elemental analysis, MS, IR spectra, NMR spectra. The crystal structure of the photocolored product of PMBP-TSC was determined by single crystal XRD analysis. The results show that the photochromic phenomenon is due to the photoisomerization from enol form to keto form. Their photochromic properties were studied by powder-UV reflectance spectra under the irradiation of 200-380 nm light. The first-order rate constants of the photocoloring reaction were found to be 7.80×10-3 s-1 for compound 1A and 1.03×10-3 s-1 for compound 2A.

  11. The Structure of gr-simple Rings%分次单环的结构

    朱彬

    2003-01-01

    A characterization of gr-simple rings is given by using the notion of componentwise-dense subrings of a full matrix ring over a division ring. As a consequence, any G-graded full matrix ring over a division ring is isomorphic to a dense subring of a full matrix ring with a good G-grading. Some conditions for a grading of a full matrix ring to be isomorphic to a good one are given, which generalize some results in: D(a)sc(a)scu, S., Lon, B., N(a)st(a)sescu, C. and Montes, J. R., Group gradingson full matrix rings, J. Algebra, 220(1999), 709-728.

  12. Determinantal rings

    Bruns, Winfried

    1988-01-01

    Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a ...

  13. Histone deacetylase inhibitor upregulates peroxisomal fatty acid oxidation and inhibits apoptotic cell death in abcd1-deficient glial cells.

    Jaspreet Singh

    Full Text Available In X-ALD, mutation/deletion of ALD gene (ABCD1 and the resultant very long chain fatty acid (VLCFA derangement has dramatically opposing effects in astrocytes and oligodendrocytes. While loss of Abcd1 in astrocytes produces a robust inflammatory response, the oligodendrocytes undergo cell death leading to demyelination in X-linked adrenoleukodystrophy (X-ALD. The mechanisms of these distinct pathways in the two cell types are not well understood. Here, we investigated the effects of Abcd1-knockdown and the subsequent alteration in VLCFA metabolism in human U87 astrocytes and rat B12 oligodendrocytes. Loss of Abcd1 inhibited peroxisomal β-oxidation activity and increased expression of VLCFA synthesizing enzymes, elongase of very long chain fatty acids (ELOVLs (1 and 3 in both cell types. However, higher induction of ELOVL's in Abcd1-deficient B12 oligodendrocytes than astrocytes suggests that ELOVL pathway may play a prominent role in oligodendrocytes in X-ALD. While astrocytes are able to maintain the cellular homeostasis of anti-apoptotic proteins, Abcd1-deletion in B12 oligodendrocytes downregulated the anti-apototic (Bcl-2 and Bcl-xL and cell survival (phospho-Erk1/2 proteins, and upregulated the pro-apoptotic proteins (Bad, Bim, Bax and Bid leading to cell loss. These observations provide insights into different cellular signaling mechanisms in response to Abcd1-deletion in two different cell types of CNS. The apoptotic responses were accompanied by activation of caspase-3 and caspase-9 suggesting the involvement of mitochondrial-caspase-9-dependent mechanism in Abcd1-deficient oligodendrocytes. Treatment with histone deacetylase (HDAC inhibitor suberoylanilide hydroxamic acid (SAHA corrected the VLCFA derangement both in vitro and in vivo, and inhibited the oligodendrocytes loss. These observations provide a proof-of principle that HDAC inhibitor SAHA may have a therapeutic potential for X-ALD.

  14. Structure of the mycobacterial ATP synthase Fo rotor ring in complex with the anti-TB drug bedaquiline.

    Preiss, Laura; Langer, Julian D; Yildiz, Özkan; Eckhardt-Strelau, Luise; Guillemont, Jérôme E G; Koul, Anil; Meier, Thomas

    2015-05-01

    Multidrug-resistant tuberculosis (MDR-TB) is more prevalent today than at any other time in human history. Bedaquiline (BDQ), a novel Mycobacterium-specific adenosine triphosphate (ATP) synthase inhibitor, is the first drug in the last 40 years to be approved for the treatment of MDR-TB. This bactericidal compound targets the membrane-embedded rotor (c-ring) of the mycobacterial ATP synthase, a key metabolic enzyme required for ATP generation. We report the x-ray crystal structures of a mycobacterial c9 ring without and with BDQ bound at 1.55- and 1.7-Å resolution, respectively. The structures and supporting functional assays reveal how BDQ specifically interacts with the rotor ring via numerous interactions and thereby completely covers the c-ring's ion-binding sites. This prevents the rotor ring from acting as an ion shuttle and stalls ATP synthase operation. The structures explain how diarylquinoline chemicals specifically inhibit the mycobacterial ATP synthase and thus enable structure-based drug design of next-generation ATP synthase inhibitors against Mycobacterium tuberculosis and other bacterial pathogens. PMID:26601184

  15. Some ISIS-Software History and Technical Background on the new FOSS Integrated Library System ABCD

    Egbert de Smet

    2010-02-01

    Full Text Available While free and open source software is gaining momentum in library automation, it is still not a trivial event to launch a full-blown integrated library system (ILS, given today's high demands on such library systems. In this article we describe the ISIS-software origins of the newly launched ABCD-software for which there is a morethan-average interest in many parts of the libraries and information communities in the developing world. Many — especially younger — librarians in the West have never heard about ISIS, its relevance and its technological concepts, so we will try to shed some light on this in order for librarians to better judge the meaning of the ABCD software for international librarianship and — why not — perhaps even for their own purposes.

  16. The propagation of hypergeometric beams through an annular apertured paraxial ABCD optical system

    By means of expanding the hard aperture function into a finite sum of complex Gaussian functions and based on the generalized Huygens–Fresnel diffraction integral, a novel approximate analytical expression of hypergeometric (HyG) beams passing through a paraxial ABCD optical system with an annular aperture is derived. The results could be reduced to the case of a circular aperture or a circular black screen. Some numerical simulations are also performed and illustrated for the propagation characteristics and focusing properties of a HyG beam through a paraxial ABCD optical system with an annular aperture. The results obtained from the approximate analytical formula provide more efficiency than the usual way of using diffraction integral formula directly. (paper)

  17. The propagation of hypergeometric beams through an annular apertured paraxial ABCD optical system

    Tang, Bin; Jiang, Chun; Zhu, Haibin; Zhou, Xin; Wang, Shuai

    2014-12-01

    By means of expanding the hard aperture function into a finite sum of complex Gaussian functions and based on the generalized Huygens-Fresnel diffraction integral, a novel approximate analytical expression of hypergeometric (HyG) beams passing through a paraxial ABCD optical system with an annular aperture is derived. The results could be reduced to the case of a circular aperture or a circular black screen. Some numerical simulations are also performed and illustrated for the propagation characteristics and focusing properties of a HyG beam through a paraxial ABCD optical system with an annular aperture. The results obtained from the approximate analytical formula provide more efficiency than the usual way of using diffraction integral formula directly.

  18. Interobserver agreement in ABCD scoring between non-stroke specialists and vascular neurologists following suspected TIA is only fair.

    Kinsella, Justin A

    2012-02-01

    The appropriateness of use and accuracy of age, blood pressure, clinical features and duration of symptoms (ABCD) scoring by non-stroke specialists while risk-stratifying patients with suspected transient ischaemic attack (TIA) are unknown. We reviewed all available ABCD data from referrals to a specialist neurovascular clinic. ABCD scoring was defined as \\'appropriate\\' in this study if an experienced vascular neurologist subsequently confirmed a clinical diagnosis of possible, probable or definite TIA, and \\'inappropriate\\' if the patient had an alternative diagnosis or stroke. Interobserver agreement between the referring physician and the neurologist was calculated. One hundred and four patients had completed ABCD referral proformas available for analysis. Forty-five (43%) were deemed appropriate, and 59 (57%) inappropriate. In the entire dataset, the neurologist agreed with the referring physician\\'s total ABCD score in only 42% of cases [kappa = 0.28]. The two most unreliable components of the scoring system were clinical features [kappa = 0.51], and duration of symptoms [kappa = 0.48]. ABCD scoring by non-stroke specialists is frequently inappropriate and inaccurate in routine clinical practice, emphasising the importance of urgent specialist assessment of suspected TIA patients.

  19. A molecular plasmonic Fano-router: Using hotspots in a single-stone ring-like structure

    Ahmadivand, Arash; Sinha, Raju; Kaya, Serkan; Pala, Nezih

    2016-05-01

    In the past decade there has been outstanding, continuing interest in developing novel structures to engineer and control light-matter interactions in subwavelength dimensions with desired optical characteristics. Herein, we propose a unique plasmonic configuration consisting of a split-ring and a nanosphere in the split section (resembles a single-stone ring). We show that this simple and antisymmetric structure is able to support pronounced antisymmetric Fano resonance at the near-infrared region, while strong hotspots form at the gap space between the split-ring terminals and the nanosphere. The antisymmetric feature of the structure facilitates strong-dependency on the polarization of the incident beam. Having strong sensitivity to the incident polarization angle, we tailored a fast plasmonic Fano-router based on the behavior of Fano resonant mode. This study could help realizing Fano resonance based photonic devices using simple and antisymmetric nanostructures.

  20. Review: The lord of the rings: Structure and mechanism of the sliding clamp loader.

    Kelch, Brian A

    2016-08-01

    Sliding clamps are ring-shaped polymerase processivity factors that act as master regulators of cellular replication by coordinating multiple functions on DNA to ensure faithful transmission of genetic and epigenetic information. Dedicated AAA+ ATPase machines called clamp loaders actively place clamps on DNA, thereby governing clamp function by controlling when and where clamps are used. Clamp loaders are also important model systems for understanding the basic principles of AAA+ mechanism and function. After nearly 30 years of study, the ATP-dependent mechanism of opening and loading of clamps is now becoming clear. Here I review the structural and mechanistic aspects of the clamp loading process, as well as comment on questions that will be addressed by future studies. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 532-546, 2016. PMID:26918303

  1. Structural interconnections and the role of heptagonal rings in endohedral trimetallic nitride template fullerenes.

    Gan, Li-Hua; Lei, Dan; Fowler, Patrick W

    2016-07-01

    Recent experiments indicate that fullerene isomers outside the classical definition can also encapsulate metallic atoms or clusters to form endohedral metallofullerenes. Our systematic study using DFT calculations, suggests that many heptagon-including nonclassical trimetallic nitride template fullerenes are similar in stability to their classical counterparts, and that conversion between low-energy nonclassical and classical parent cages via Endo-Kroto insertion/extrusion of C2 units and Stone-Wales isomerization may facilitate the formation of endohedral trimetallic nitride fullerenes. Close structural connections are found between favored isomers of trimetallic nitride template fullerenes from C78 to C82 . It appears that the lower symmetry and local deformations associated with introduction of a heptagonal ring favor encapsulation of intrinsically less symmetrical mixed metal nitride clusters. © 2016 Wiley Periodicals, Inc. PMID:27282122

  2. Body-insensitive Multi-Mode MIMO Terminal Antenna of Double-Ring Structure

    Zhao, Kun; Zhang, Shuai; Ishimiya, Katsunori;

    2015-01-01

    In this paper, we propose a novel multimode multi-input multi-output (MIMO) antenna system composed of a dual-element MIMO cellular antenna and dual-element MIMO Wi-Fi antenna for mobile terminal applications. The antenna system has a double-ring structure and can be integrated with the metal frame...... of mobile terminals. With the multimode excitation, the MIMO cellular antenna can operate at 830-900 MHz, 1700-2200 MHz, and 2400-2700 MHz, for 2G, 3G, and LTE bands, respectively. The MIMO Wi-Fi antenna can cover two Wi-Fi bands from 2.4 to 2.5 GHz and from 5.2 to 5.8 GHz. The effect of a user's body...

  3. Complex dynamics analysis of impulsively coupled Duffing oscillators with ring structure

    Impulsively coupled systems are high-dimensional non-smooth systems that can exhibit rich and complex dynamics. This paper studies the complex dynamics of a non-smooth system which is unidirectionally impulsively coupled by three Duffing oscillators in a ring structure. By constructing a proper Poincaré map of the non-smooth system, an analytical expression of the Jacobian matrix of Poincaré map is given. Two-parameter Hopf bifurcation sets are obtained by combining the shooting method and the Runge–Kutta method. When the period is fixed and the coupling strength changes, the system undergoes stable, periodic, quasi-periodic, and hyper-chaotic solutions, etc. Floquet theory is used to study the stability of the periodic solutions of the system and their bifurcations. (paper)

  4. The ABCD matrix for parabolic reflectors and its application to astigmatism free four-mirror cavities

    Dupraz, K.; Cassou, K.; Martens, A.; Zomer, F.

    2015-10-01

    The ABCD matrix for parabolic reflectors is derived for any incident angles. It is used in numerical studies of four-mirror cavities composed of two flat and two parabolic mirrors. Constraints related to laser beam injection efficiency, optical stability, cavity-mode, beam-waist size and high stacking power are satisfied. A dedicated alignment procedure leading to stigmatic cavity-modes is employed to overcome issues related to the optical alignment of parabolic reflectors.

  5. Value of ABCD2 in predicting early ischemic stroke in patients diagnosed with transient ischemic attack.

    Mojtaba Chardoli; Alireza Khajavi; Mohsen Nouri; Vafa Rahimi-Movaghar

    2013-01-01

    As a significant number of patients diagnosed with transient ischemic attack (TIA) at emergency department are at risk to develop TIA or cerebral vascular accident (CVA), several attempts have been made to figure out a predictive method to detect those at higher risk of such attacks. We aimed to evaluate the role of ABCD2 scoring which includes age, blood pressure, clinical symptoms, diabetes mellitus, and duration of symptoms in predicting short term outcome of the patients presenting with T...

  6. Predicting value of ABCD2 in early ischemic stroke in patients diagnosed with transient ischemic attack

    Chardoli, Mojtaba; Khajavi, Alireza; Nouri, Mohsen; Rahimi-Movaghar, Vafa

    2012-01-01

    Abstract: Background: As a significant number of patients diagnosed with transient ischemic attack (TIA) at emergency department are at risk to develop TIA or cerebral vascular accident (CVA), several attempts have been made to figure out a predictive method to detect those at higher risk of such attacks. Therefore, the present study was aimed to evaluate the role of ABCD2 scoring including age, blood pressure, clinical features, duration, and diabetes mellitus (DM), in predicting short term ...

  7. Study on ABCD Analysis Technique for Business Models, Business Strategies, Operating Concepts & Business Systems

    Aithal, Sreeramana

    2015-01-01

    Studying the implications of a business model, choosing success strategies, developing viable operational concepts or evolving a functional system, it is important to analyse it in all dimensions. For this purpose, various analysing techniques/frameworks are used. This paper is a discussion on how to use an innovative analysing framework called ABCD model on a given business model, or on a business strategy or an operational concept/idea or business system. Based on four constructs Advantages...

  8. New decomposition of the Fresnel operator corresponding to the optical transformation in ABCD-systems

    By virtue of the coherent state representation of the newly introduced Fresnel operator and its group product property, we obtain new decomposition of the Fresnel operator as the product of the quadratic phase operator, the squeezing operator, and the fractional Fourier transformation operator, which in turn sheds light on the matrix optics design of ABCD-systems. The new decomposition for the two-mode Fresnel operator is also obtained by the use of entangled state representation

  9. Decameric SelA•tRNA(Sec) ring structure reveals mechanism of bacterial selenocysteine formation.

    Itoh, Yuzuru; Bröcker, Markus J; Sekine, Shun-ichi; Hammond, Gifty; Suetsugu, Shiro; Söll, Dieter; Yokoyama, Shigeyuki

    2013-04-01

    The 21st amino acid, selenocysteine (Sec), is synthesized on its cognate transfer RNA (tRNA(Sec)). In bacteria, SelA synthesizes Sec from Ser-tRNA(Sec), whereas in archaea and eukaryotes SepSecS forms Sec from phosphoserine (Sep) acylated to tRNA(Sec). We determined the crystal structures of Aquifex aeolicus SelA complexes, which revealed a ring-shaped homodecamer that binds 10 tRNA(Sec) molecules, each interacting with four SelA subunits. The SelA N-terminal domain binds the tRNA(Sec)-specific D-arm structure, thereby discriminating Ser-tRNA(Sec) from Ser-tRNA(Ser). A large cleft is created between two subunits and accommodates the 3'-terminal region of Ser-tRNA(Sec). The SelA structures together with in vivo and in vitro enzyme assays show decamerization to be essential for SelA function. SelA catalyzes pyridoxal 5'-phosphate-dependent Sec formation involving Arg residues nonhomologous to those in SepSecS. Different protein architecture and substrate coordination of the bacterial enzyme provide structural evidence for independent evolution of the two Sec synthesis systems present in nature. PMID:23559248

  10. Kurtosis parameters of super Lorentz-Gauss beams through a paraxial and real ABCD optical system

    Zhou Guo-Quan

    2011-01-01

    Based on the propagation equation of higher-order intensity moments,analytical propagation expressions for the kurtosis parameters of a super Lorentz-Ganss (SLG) SLG01 beam through a paraxial and real ABCD optical system are derived.By replacing the parameters in the expressions of the kurtosis parameters of the SLG01 beam,the kurtosis parameters of the SLG10 and SLG11 beams through a paraxial and real ABCD optical system can be easily obtained.The kurtosis parameters of an SLGo1 beam through a paraxial and real ABCD optical system depend on two ratios.One is the ratio of the transfer matrix element B to the product of the transfer matrix element A and the difffraction-free range of the super-Lorentzian part.The other is the ratio of the width parameter of the super-Lorentzian part to the waist of the Gaussian part. As a numerical example,the properties of the kurtosis parameters of an SLG01 beam propagating in free space are illustrated.The influences of different parameters on the kurtosis parameters of an SLG01 beam are analysed in detail.

  11. Alternative loop rings

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  12. Characterization of ring-like F-actin structure as a mechanical partner for spindle positioning in mitosis.

    Huan Lu

    Full Text Available Proper spindle positioning and orientation are essential for accurate mitosis which requires dynamic interactions between microtubule and actin filament (F-actin. Although mounting evidence demonstrates the role of F-actin in cortical cytoskeleton dynamics, it remains elusive as to the structure and function of F-actin-based networks in spindle geometry. Here we showed a ring-like F-actin structure surrounding the mitotic spindle which forms since metaphase and maintains in MG132-arrested metaphase HeLa cells. This cytoplasmic F-actin structure is relatively isotropic and less dynamic. Our computational modeling of spindle position process suggests a possible mechanism by which the ring-like F-actin structure can regulate astral microtubule dynamics and thus mitotic spindle orientation. We further demonstrated that inhibiting Plk1, Mps1 or Myosin, and disruption of microtubules or F-actin polymerization perturbs the formation of the ring-like F-actin structure and alters spindle position and symmetric division. These findings reveal a previously unrecognized but important link between mitotic spindle and ring-like F-actin network in accurate mitosis and enables the development of a method to theoretically illustrate the relationship between mitotic spindle and cytoplasmic F-actin.

  13. Ring Theory

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  14. Frequent inaccuracies in ABCD(2) scoring in non-stroke specialists' referrals to a daily Rapid Access Stroke Prevention service.

    Bradley, David

    2013-09-15

    The \\'accuracy\\' of age, blood pressure, clinical features, duration and diabetes (ABCD(2)) scoring by non-stroke specialists referring patients to a daily Rapid Access Stroke Prevention (RASP) service is unclear, as is the accuracy of ABCD(2) scoring by trainee residents. In this prospective study, referrals were classified as \\'confirmed TIAs\\' if the stroke specialist confirmed a clinical diagnosis of possible, probable or definite TIA, and \\'non-TIAs\\' if patients had a TIA mimic or completed stroke. ABCD(2) scores from referring physicians were compared with scores by experienced stroke specialists and neurology\\/geriatric medicine residents at a daily RASP clinic; inter-observer agreement was examined. Data from 101 referrals were analysed (mean age=60.0years, 58% male). The median interval between referral and clinic assessment was 1day. Of 101 referrals, 52 (52%) were \\'non-TIAs\\': 45 (86%) of 52 were \\'TIA mimics\\' and 7 (14%) of 52 were completed strokes. There was only \\'fair\\' agreement in total ABCD(2) scoring between referring physicians and stroke specialists (κ=0.37). Agreement was \\'excellent\\' between residents and stroke specialists (κ=0.91). Twenty of 29 patients scored as \\'moderate to high risk\\' (score 4-6) by stroke specialists were scored \\'low risk\\' (score 0-3) by referring physicians. ABCD(2) scoring by referring doctors is frequently inaccurate, with a tendency to underestimate stroke risk. These findings emphasise the importance of urgent specialist assessment of suspected TIA patients, and that ABCD(2) scores by non-stroke specialists cannot be relied upon in isolation to risk-stratify patients. Inter-observer agreement in ABCD(2) scoring was \\'excellent\\' between residents and stroke specialists, indicating short-term training may improve accuracy.

  15. Gaps, rings, and non-axisymmetric structures in protoplanetary disks - Emission from large grains

    Ruge, J P; Wolf, S; Dzyurkevich, N; Fromang, S; Henning, Th; Klahr, H; Meheut, H

    2016-01-01

    Dust grains with sizes around (sub)mm are expected to couple only weakly to the gas motion in regions beyond 10 au of circumstellar disks. In this work, we investigate the influence of the spatial distribution of such grains on the (sub)mm appearance of magnetized protoplanetary disks. We perform non-ideal global 3D magneto-hydrodynamic stratified disk simulations including particles of different sizes (50 micron to 1 cm), using a Lagrangian particle solver. We calculate the spatial dust temperature distribution, including the dynamically coupled submicron-sized dust grains, and derive ideal continuum re-emission maps of the disk through radiative transfer simulations. Finally, we investigate the feasibility to observe specific structures in the thermal re-emission maps with the Atacama Large Millimeter/submillimeter Array (ALMA). The pressure bump close to the outer edge of the dead-zone leads to particle trapping in ring structures. More specifically, vortices in the disk concentrate the dust and create an ...

  16. Inhibitory and neutral antibodies to Plasmodium falciparum MSP119 form ring structures with their antigen.

    Dekker, Carien; Uthaipibull, Chairat; Calder, Lesley J; Lock, Matthew; Grainger, Munira; Morgan, William D; Dodson, Guy G; Holder, Anthony A

    2004-09-01

    Blood-stage malaria vaccine candidates include surface proteins of the merozoite. Antibodies to these proteins may either block essential steps during invasion or render the merozoite susceptible to phagocytosis or complement-mediated degradation. Structural information on merozoite surface proteins complexed to antibodies provides crucial information for knowledge-based vaccine design. The major merozoite surface protein MSP1 is an abundant surface molecule in Plasmodium falciparum. Only a subset of antibodies against MSP119 inhibits invasion (inhibitory antibodies), whereas other antibodies binding to MSP119 have no effect on invasion (neutral antibodies). Here we report on the complex of MSP119 with both inhibitory monoclonal antibody 12.10 and neutral monoclonal antibody 2F10. The complexes were established using both whole IgG's and Fab fragments, and analysed by dynamic light scattering, electron microscopy and analytical ultra centrifugation. Specific ring structures were formed in the ternary complex with the two antibodies, providing direct evidence of non-overlapping epitopes on MSP119. Mutational studies also indicated that the epitopes of the inhibitory and neutral antibodies are spatially remote. PMID:15279960

  17. One Ring to Encompass them All A giant stellar structure that surrounds the Galaxy

    Ibata, R A; Lewis, G F; Ferguson, A M N; Tanvir, N R

    2003-01-01

    We present evidence that the curious stellar population found by the Sloan Digital Sky Survey in the Galactic anticentre direction extends to other distant fields that skirt the plane of the Milky Way. New data, taken with the INT Wide Field Camera show a similar population, narrowly aligned along the line of sight, but with a Galactocentric distance that changes from ~15 kpc to \\~20 kpc (over ~100 degrees on the sky). Despite being narrowly concentrated along the line of sight, the structure is fairly extended vertically out of the plane of the Disk, with a vertical scale height of 0.75+/-0.04 kpc. This finding suggests that the outer rim of the Galaxy ends in a low-surface brightness stellar ring. Presently available data do not allow us to ascertain the origin of the structure. One possibility is that it is the wraith of a satellite galaxy devoured long-ago by the Milky Way, though our favoured interpretation is that it is a perturbation of the disk, possibly the result of ancient warps. Assuming that the ...

  18. Nerve ring of the hypostome in hydra. I. Its structure, development, and maintenance

    Koizumi, O; Itazawa, M; Mizumoto, H;

    1992-01-01

    The anatomy and developmental dynamics of the nerve ring in the hypostome of Hydra oligactis were examined immunocytochemically with an antiserum against a neuropeptide and with neuron-specific monoclonal antibodies. The nerve ring is unique in the mesh-like nerve net of hydra. It is a distinct...

  19. Value of ABCD2-F in Predicting Cerebral Ischemic Attacks: Three Months Follow-Up after the Primary Attack.

    Chardoli, Mojtaba; Firoozabadi, Nader H; Nouri, Mohsen; Rahimi-Movaghar, Vafa

    2016-06-01

    Cerebrovascular attack (CVA) and transient ischemic attack (TIA) are major causes of emergency department visits around the globe. A significant number of these patients may experience repeat attacks if left untreated. Several risk stratifying scoring systems have been developed in recent years to point out the high risk patients. ABCD2 is based on age, blood pressure, clinical status, diabetes mellitus, and duration of symptoms and is used commonly for this purpose. In this study, we were to enhance its sensitivity and specificity with the addition of another criterion namely atrial fibrillation and making ABCD2-F. A prospective study in two hospitals was performed and 138 patients diagnosed with TIA/CVA were enrolled. Demographic, clinical, and paraclinical data of all patients were registered. All patients were followed for three months for any sign or symptom of a recurrent ischemic attack. Recurrent ischemic attacks happened in 9.4% of the patients. None of the criteria of ABCD2-F was associated with higher chance of ischemic attacks. Similarly, ABCD2-F was not different between patients with or without repeat cerebral ischemia. The addition of atrial fibrillation to ABCD2 did not enhance the accuracy of this scoring system to detect patients high risk for repeat cerebral ischemia. More studies in the future to improve sensitivity and specificity of this test are warranted. PMID:27306346

  20. The phase structure of higher-dimensional black rings and black holes

    We construct an approximate solution for an asymptotically flat, neutral, thin rotating black ring in any dimension D ≥ 5 by matching the near-horizon solution for a bent boosted black string, to a linearized gravity solution away from the horizon. The rotating black ring solution has a regular horizon of topology S1 x SD-3 and incorporates the balancing condition of the ring as a zero-tension condition. For D = 5 our method reproduces the thin ring limit of the exact black ring solution. For D ≥ 6 we show that the black ring has a higher entropy than the Myers-Perry black hole in the ultra-spinning regime. By exploiting the correspondence between ultra-spinning black holes and black membranes on a two-torus, we take steps towards qualitatively completing the phase diagram of rotating blackfolds with a single angular momentum. We are led to propose a connection between MP black holes and black rings, and between MP black holes and black Saturns, through merger transitions involving two kinds of 'pinched' black holes. More generally, the analogy suggests an infinite number of pinched black holes of spherical topology leading to a complicated pattern of connections and mergers between phases

  1. Evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter

    Camargo, F. [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Caixa Postal 11049, Sao Paulo SP 05422-970, Brasil (Brazil); Khoury, H.J.; Nascimento, C.R.; Asfora, V.K. [Universidade Federal de Pernambuco, Av. Prof. Luiz Freire 1000, Recife PE 50740-540, Brasil (Brazil); Bueno, C.C. [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Caixa Postal 11049, Sao Paulo SP 05422-970, Brasil (Brazil); Pontificia Universidade Catolica de Sao Paulo, Rua Marques de Paranagua 111, Sao Paulo SP 01303-050, Brasil (Brazil)], E-mail: ccbueno@ipen.br

    2007-09-21

    In this paper, we describe the results obtained for the evaluation of a multi-guard ring (MGR) structure diode as diagnostic X-ray dosimeter. This device was developed in the framework of R and D programs for the future CMS experiment at the Large Hadron Collider (LHC) with high radiation hardness to fulfill the requirements from this accelerator environment. In order to use the MGR diode as a dosimeter, it was connected in the photovoltaic mode to the input of an integrating electrometer and positioned at the center of an X-ray beam, beside a previously calibrated ionization chamber. The dependence of the diode response on the X-ray beam doses was evaluated for 35-90 kV X-ray generator bias supply, with doses in the range of 50 {mu}Gy-5 mGy. The good linearity of the dose-response curve obtained showed the MGR diode dosimeter to be a reliable alternative method for diagnostic X-ray dosimetry.

  2. A properly configured ring structure is critical for the function of the mitochondrial DNA recombination protein, Mgm101.

    Nardozzi, Jonathan D; Wang, Xiaowen; Mbantenkhu, MacMillan; Wilkens, Stephan; Chen, Xin Jie

    2012-10-26

    Mgm101 is a Rad52-type recombination protein of bacteriophage origin required for the repair and maintenance of mitochondrial DNA (mtDNA). It forms large oligomeric rings of ∼14-fold symmetry that catalyze the annealing of single-stranded DNAs in vitro. In this study, we investigated the structural elements that contribute to this distinctive higher order structural organization and examined its functional implications. A pair of vicinal cysteines, Cys-216 and Cys-217, was found to be essential for mtDNA maintenance. Mutations to the polar serine, the negatively charged aspartic and glutamic acids, and the hydrophobic amino acid alanine all destabilize mtDNA in vivo. The alanine mutants have an increased propensity of forming macroscopic filaments. In contrast, mutations to aspartic acid drastically destabilize the protein and result in unstructured aggregates with severely reduced DNA binding activity. Interestingly, the serine mutants partially disassemble the Mgm101 rings into smaller oligomers. In the case of the C216S mutant, a moderate increase in DNA binding activity was observed. By using small angle x-ray scattering analysis, we found that Mgm101 forms rings of ∼200 Å diameter in solution, consistent with the structure previously established by transmission electron microscopy. We also found that the C216A/C217A double mutant tends to form broken rings, which likely provide free ends for seeding the growth of the super-stable but functionally defective filaments. Taken together, our data underscore the importance of a delicately maintained ring structure critical for Mgm101 activity. We discuss a potential role of Cys-216 and Cys-217 in regulating Mgm101 function and the repair of damaged mtDNA under stress conditions. PMID:22948312

  3. Geology, structure, and statistics of multi-ring basins on Mars

    Available data on Martian multi-ring basins were compiled and evaluated using the new 1:15 million scale geologic maps of Mars and global topography was revised as base maps. Published center coordinates and ring diameters of Martian basins were plotted by computer and superimposed onto the base maps. In many cases basin centers or ring diameters or both had to be adjusted to achieve a better fit to the revised maps. It was also found that additional basins can explain subcircular topographic lows as well as map patterns of old Noachian materials, volcanic plains units, and channels in the Tharsis region

  4. THE CHEMICAL EVOLUTION OF THE MONOCEROS RING/GALACTIC ANTICENTER STELLAR STRUCTURE

    The origin of the Galactic Anticenter Stellar Structure (GASS) or 'Monoceros Ring' - a low-latitude overdensity at the edge of the Galactic disk spanning at least the second and third Galactic quadrants-remains controversial. Models for the origin of GASS generally fall into scenarios where either it is a part (e.g., warp) of the Galactic disk or it represents tidal debris from the disruption of a Milky Way (MW) satellite galaxy. To further constrain models for the origin of GASS, we derive chemical abundance patterns from high-resolution spectra for 21 M giants spatially and kinematically identified with it. The abundances of the (mostly) α-element, titanium, and s-process elements, yttrium and lanthanum, for these GASS stars are found to be lower at the same [Fe/H] than those for MW stars, but similar to those of stars in the Sagittarius stream, other dwarf spheroidal galaxies, and the Large Magellanic Cloud. This demonstrates that GASS stars have a chemical enrichment history typical of dwarf galaxies-and unlike those of typical MW stars (at least MW stars near the Sun). Nevertheless, these abundance results cannot definitively rule out the possibility that GASS was dynamically created out of a previously formed, outer MW disk because ΛCDM-based structure formation models show that galactic disks grow outward by accretion of dwarf galaxies. On the other hand, the chemical patterns seen in GASS stars do provide striking verification that accretion of dwarf galaxies has indeed happened at the edge of the MW disk.

  5. Allenylphosphonates with a 1,3,2-dioxaphosphorinane ring: Synthesis, structures, stability and utility

    N N Bhuvan Kumar; Manab Chakravarty; N Satish Kumar; K V Sajna; K C Kumara Swamy

    2009-01-01

    Synthesis, structures and stability (thermal and air) of allenylphosphonates of the type (OCH2CMe2CH2O)P(O)C(R)=C=CR'R" and [R"R'C=C=C(R)P(O)(OCH2)2]2C are discussed. Thermally activated dimerization (cycloaddition) of (OCH2CMe2CH2O)P(O)C(H)=C=CMe2 leads to the phosphonocyclobutane [(OCH2CMe2CH2O)P(O)C(H)=]2[C-CMe2]2 (18). Many of these allenes undergo addition of diethylamine to lead to enaminophosphonates that are readily hydrolysed by water to lead to -ketophosphonates. The latter compounds are useful as Horner-Wadsworth-Emmons (HWE) reagents. Molecular structures of (OCH2CMe2CH2O)P(O)C(CH2OH)=C=CH2 (6), [H2C=C=C(H)P(O)(OCH2)2]2C (9), (OCH2CMe2CH2O)P(O)CH=C=CH2 (12), [(OCH2CMe2CH2O)P(O)C(H)=]2[C-CMe2]2 (18), and the -ketophosphonate (OCH2CMe2CH2O)P(O)CH2)-C(O)CHMe2 (24) have been determined. In compound 6, intermolecular hydrogen bonding between the phosphoryl oxygen and the hydroxyl group leading to an infinite chain is observed. In 6, there is a significant deviation (ca 7°) from the orthogonality expected between the planes containing 4 atoms of (a) H2C=C and (b) C=C(H)P in the allene part. In 9, weak C-H…O interaction between the phosphoryl oxygen atom and a CH2 proton of the six-membered ring is present.

  6. Genetic analysis of the modABCD (molybdate transport) operon of Escherichia coli.

    Maupin-Furlow, J A; Rosentel, J K; Lee, J.H.; Deppenmeier, U; Gunsalus, R P; Shanmugam, K. T.

    1995-01-01

    DNA sequence analysis of the modABCD operon of Escherichia coli revealed the presence of four open reading frames. The first gene, modA, codes for a 257-amino-acid periplasmic binding protein enunciated by the presence of a signal peptide-like sequence. The second gene (modB) encodes a 229-amino-acid protein with a potential membrane location, while the 352-amino-acid ModC protein (modC product) contains a nucleotide-binding motif. On the basis of sequence similarities with proteins from othe...

  7. Low Temperature Photoluminescence Kinetics of Double-Ring Structured GaAs Quantum Dots.

    Myoung, Soung; Mun, Ok Mi; Yim, Sang-Youp; Kim, Jong Su

    2015-11-01

    This work is focused on spectroscopically characterizing kinetic properties of concentric quantum-ring complexes of GaAs quantum dots. Quantum-ring (or double-ring) GaAs quantum dots, embedded in an Al0.3Ga0.7As barrier layer, were grown by a droplet epitaxy method during molecular beam epitaxy on a GaAs (001) substrate. Emission peaks of photoluminescence spectra with different excitation power, were measured as 702 nm at 0.17 mW and 690 nm at 400 mW, were blue-shifted as the excitation power increased. In addition, excitation laser power dependence of time-resolved photoluminescence of double-ring GaAs quantum dots at 10 K under 400 nm excitation wavelength was performed, revealing that photoluminescence lifetime slowly decreased in comparison to that of single disc-like quantum dots as excitation power increased, implying that carrier transfer between inner ring and outer ring could slow down the decay process. The luminescence lifetime at 10 K increased from 245 to 409 ps in the range from 0.17 to 400 mW of excitation power. PMID:26726575

  8. Population-based study of ABCD2 score, carotid stenosis, and atrial fibrillation for early stroke prediction after transient ischemic attack: the North Dublin TIA study.

    Sheehan, Orla C

    2010-05-01

    Transient ischemic attack (TIA) etiologic data and the ABCD(2) score may improve early stroke risk prediction, but studies are required in population-based cohorts. We investigated the external validity of the ABCD(2) score, carotid stenosis, and atrial fibrillation for prediction of early recurrent stroke after TIA.

  9. Detecting supermassive binary black holes with VLBI - discovery of a ring-structure in 3C454.3

    We report the detection of the first VLBI ring-structure around the core of an AGN - around the core of the quasar 3C454.3. This ring-structure starts being visible in VLBI maps around 1996. It expands with an apparent velocity between 0.11±0.01mas/yr and 0.18±0.01mas/yr and dominates the pc-scale structure for at least 14 years. This is the result of a re-analysis of 41 VLBA data sets at six different radio frequencies observed between 1995.57 and 2011.48. We observe a correlation between radio flaring, flux-density variability, a ring-structure and kinematic properties of the jet. Taken together, it is tempting to see a causal connection and to explain all of this geometrically. The kinematic changes as well as the changes in the flaring characteristics might be caused by a change of the angle to the line of sight towards the observer. This behaviour resembles our findings for 0735+178 - with 3C454.3 being the second AGN to reveal kinematic mode changes. These mode changes could be explained by the presence of a supermassive binary black hole. 3C454.3 had been modelled as a binary black hole before.

  10. Conformational Transformation of Five-Membered Rings: the Gas Phase Structure of 2-METHYLTETRAHYDROFURAN

    Van, Vinh; Nguyen, Ha Vinh Lam; Stahl, Wolfgang

    2015-06-01

    2-Methyltetrahydrofuran (2-MeTHF) is a promising environmentally friendly solvent and biofuel component which is derived from renewable resources. Following the principles of Green Chemistry, 2-MeTHF has been evaluated in various fields like organometallics, metathesis, and biosynthesis on the way to more eco-friendly syntheses. Cyclopentane as the prototype of five-membered rings is well-known to exist as twist or envelope structures. However, the conformational analysis of its heterocyclic derivative 2-methyl-tetrahydrothiophene (MTTP) yielded two stable twist conformers and two envelope transition states. Here, we report on the heavy atom r_s structure of the oxygen-analog of MTTP, 2-MeTHF, studied by a combination of molecular beam Fourier transform microwave spectroscopy and quantum chemistry. One conformer of 2-MeTHF was observed and highly accurate molecular parameters were determined using the XIAM program. In addition, all 13C-isotopologues were assigned in natural abundance of 1%. A structural determination based on the r_s positions of all carbon atoms was achieved via Kraitchman's equations. The methyl group in 2-MeTHF undergoes internal rotation and causes A-E splittings of the rotational lines. The barrier was calculated to be 1142 wn at the MP2/6-311++G(d,p) level of theory, which is rather high. Accordingly, narrow A-E splittings could be observed for only a few transitions. However, the barrier height could be fitted while the angles between the internal rotor axis and the principal axes of inertia were taken from the experimental geometry. V. Pace, P. Hoyos, L. Castoldi, P. Domínguez de María, A. R. Alcántara, ChemSusChem 5 (2012), 1369-1379. a) D. F. Aycock, Org. Process Res. Dev. 11 (2007),156-159. b) M. Smoleń, M. Kȩdziorek, K. Grela, Catal. Commun. 44 (2014), 80-84. V. Van, C. Dindic, H.V.L. Nguyen, W. Stahl, ChemPhysChem 16 (2015), 291-294. H. Hartwig, H. Dreizler, Z. Naturforsch. A 51 (1996), 923-932. J. Kraitchman, Am. J. Phys. 21

  11. Strain distribution and electronic structures of the InAs/GaAs quantum ring molecule in an applied electric field

    2010-01-01

    The strain distribution and electronic structures of the InAs/GaAs quantum ring molecule are calculated via the finite element method.In our model,three identical InAs quantum rings are aligned vertically and embedded in the cubic GaAs barrier.Considering the band edge modification induced by the strain,the electronic ground state and the dependence of ground state energy on geometric parameters of the quantum ring molecule are investigated.The change of localization of the wavefunction resulting from the applied electric field along the growth direction is observed.The ground state energy decreases as the electric field intensity increases in a parabolic-like mode.The electric field changes the monotonic dependence of the energy level on the inter-ring distance into a non-monotonic one.However,the electric field has no effect on the relationships between the energy level and other geometric parameters such as the inner radius and outer radius.

  12. Structure, stratigraphy, and eruption dynamics of a young tuff ring: Hanauma Bay, O'ahu, Hawai'i

    Rottas, K. M.; Houghton, B. F.

    2012-09-01

    The Hanauma Bay-Koko Head complex is one of several young volcanic landforms along the Koko fissure, in southeastern O'ahu. The Hanauma Bay region of the complex comprises two nested tuff rings, inner and outer Hanauma Bay, and multiple smaller vents. The internal structure of the inner tuff ring, well exposed due to subsequent breaching by the ocean and wave erosion, indicates that it formed during a minimum of five distinct phases of deposition that produced five mappable units. Significant inward collapses generated major unconformities that separate the units exposed in the inner wall. The planes of failure are cut by narrow steep-walled, locally overhung channels and gullies, suggesting that the collapse events were each followed by short time breaks during which the deposits were eroded by rainfall runoff. Within each pyroclastic unit, there are many local slump scars and unconformities, suggesting that minor instability of the inner wall was a near-constant feature. From bedding sags and surge bed forms, it is apparent that the vent shifted at least twice during tuff ring growth. Ballistic blocks in the youngest unit indicate that the eruption overlapped in time with a separate eruption to the north, most likely to be that of the Kahauloa tuff ring 880 m away.

  13. Interaction of Al-induced peptide backbone ring structure with the sidechains of His, Phe, Trp and Tyr

    吴清雷; 宋波

    2015-01-01

    Aluminium is widely used as an antimicrobial coagulant, food additive, and cookware. However, many reports indicate that aluminium may be a critical factor in many amyloid diseases, such as Alzheimer’s disease and Parkinson’s disease. Unfortunately, the underlying mechanism is still poorly understood, which limits efforts to prevent and treat these diseases. In this paper, using an ab initio method, we studied the interaction of Al-backbone ring structure with theπ-electron-rich sidechains of His, Phe, Trp, and Tyr. We found that in the absence of water, the Al-backbone ring can stably bind with those sidechains. In the presence of water, the Al-backbone ring can bind to the His sidechain and cannot bind to the other sidechains. As revealed by further investigations, this could be attributed to the fact that there was a coordinate bond of the Al-backbone ring with the His sidechain, while there were theπ-πstacking and cation-π-like interactions with the other sidechains. These findings potentially provide a molecular understanding of Al-related toxicity, and may be helpful in designing drugs for those aforementioned aluminum-linked diseases and encourage treatment of Al-polluted water.

  14. A thermal active restrained shrinkage ring test to study the early age concrete behaviour of massive structures

    BRIFFAUT, M; BENDOUJEMA, F; Torrenti, Jean Michel; NAHAS, G

    2011-01-01

    In massive concrete structures, cracking may occur during hardening, especially if autogenous and thermal strains are restrained. The concrete permeability due to this cracking may rise significantly and thus increase leakage (in tank, nuclear containment ) and reduce the durability. The restrained shrinkage ring test is used to study the early age concrete behaviour (delayed strains evolution and cracking). This test shows, at 20 °C and without drying, for a concrete mix which is representat...

  15. Provenance effect on the ring structure of teak (Tectona grandis L.f.) wood by X-ray microdensitometry

    Nocetti, Michela; Chaix, Gilles; Nicola MACCHIONI

    2011-01-01

    • Context : Teak (Tectona grandis L.f.) is a tropical timber which is appreciated worldwide and has been planted into many regions of the tropics. It is essential to obtain information about provenance variation of basic wood properties in order to preserve the wood quality of end-products derived from future plantations. Figuring is one of the wood characteristics valued for panelling and furniture and it is an important parameter to evaluate the quality of teak wood. The ring structure affe...

  16. Rb-Sr dating of a postorogenic Svecokarelian composite dike within the Siljan ring structure, central Sweden

    Rb-Sr dating of a postorogenic Svecokarelian composite dike from a huge clast within the Siljan ring structure, central Sweden, gives a two point whole rock reference line of 1646 Ma and a whole-rock-mineral isochron age of 1515+-21Ma. Thus, the meteorite impact during Devonian time does not seem to have greatly affected the Rb-Sr whole rock and mineral systems but only indirectly through secondary effects. (Authors)

  17. First results on radiation damage studies using n+/p/p+ diodes fabricated with multi-guard ring structures

    First measurements of silicon PIN diodes and multi-guard structures, fabricated from 10 kΩ cm p-type material in an n+/p/p+ configuration are presented. Studies of the effects of irradiation with 2.0x1014 p/cm2 at 63.3 MeV on the charge collection efficiency, leakage current, and breakdown are presented, along with studies of different guard ring configurations

  18. An Origin of Multiple Ring Structure and Hidden Planets in HL Tau: A Unified Picture by Secular Gravitational Instability

    Takahashi, Sanemichi Z

    2016-01-01

    Recent ALMA observation has revealed multiple ring structures formed in a protoplanetary disk around HL Tau. Prior to the ALMA observation of HL Tau, theoretical analysis of secular gravitational instability (GI) described a possible formation of multiple ring structures with separations of 13 AU around a radius of 100 AU in protoplanetary disks under certain conditions. In this article, we reanalyze the viability of secular GI by adopting the physical values inferred from the observations. We derive the radial distributions of the most unstable wavelength and the growth timescale of secular GI and verify that secular GI can form the ring structures observed in HL Tau. When a turbulent viscosity coefficient $\\alpha$ remains to be small in inner region of the disk, secular GI grows in the whole disk. Thus, the formation of planetary mass objects should occur first in the inner region as a result of gravitational fragmentation after the non-linear growth of secular GI. In this case, resulting objects are expect...

  19. K-本原环的结构%Structure of K-primitive Rings

    张志旭; 汪宏远; 赵鹏起; 刘大波; 刘赞勤; 陈琳珏

    2011-01-01

    This note is devoted to the study of K-primitive rings. It is proved that a prime ring R is K-primitive if and only if its a nonzero ideal is K-primitive, if and only if eRe is K-primitive for some nonzero idempotent e to R. It is also shown that GPI prime rings are K-primitive. Related results in the literatures are generalized.%研究K-本原环.证明了素环R是K-本原环当且仅当R含有一个非零理想I是K-本原环,当且仅当eRe是K-本原环,其中e是R的非零幂等元.并证明了GPI素环是K-本原环.推广了文献中的相应结果.

  20. Self assembly of microparticles in stable ring structures in an optical trap

    Haldar, Arijit; Roy, Basudev; Gupta, S Dutta; Banerjee, Ayan

    2011-01-01

    Micro-particle self assembly under the influence of optical forces produced by higher order optical beams or by projection of a hologram into the trapping volume is well known. In this paper, we report the spontaneous formation of a ring of identical microspheres (each with diameter 1.1 um in conventional single beam optical tweezers having standing wave geometry with the sample chamber consisting of a cover slip and glass slide, and a usual TEM00 Gaussian beam. The effects of different experimental parameters on the ring formation are studied extensively. The experimental observations are backed by theoretical simulations based on a plane wave decomposition of the forward and backward propagating Gaussian beams. The ring patterns are shown to be caused due to geomterical aberrations produced by focusing the Gaussian beam using a high numerical aperture microscope objective into stratified media. It is found that the thickness of the stratified media and the standing wave geometry itself play a critical role ...

  1. Multi-resonance split ring resonator structures at sub-terahertz frequencies

    Galal, Hossam

    2016-01-01

    This paper reports on the computational development of novel architectures of multi-resonance Split Ring Resonators (SRRs), for efficient manipulation of Terahertz (THz) frequency beams. The conceived resonators are based on both a capacitive and inductive scheme. Simulation results have been obtained for a 60 GHz to 240 GHz operational bandwidth.

  2. A thermal active restrained shrinkage ring test to study the early age concrete behaviour of massive structures

    In massive concrete structures, cracking may occur during hardening, especially if autogenous and thermal strains are restrained. The concrete permeability due to this cracking may rise significantly and thus increase leakage (in tank, nuclear containment...) and reduce the durability. The restrained shrinkage ring test is used to study the early age concrete behaviour (delayed strains evolution and cracking). This test shows, at 20 oC and without drying, for a concrete mix which is representative of a French nuclear power plant containment vessel (w/c ratio equal to 0.57), that the amplitude of autogenous shrinkage (about 40 μm/m for the studied concrete mix) is not high enough to cause cracking. Indeed, in this configuration, thermal shrinkage is not significant, whereas this is a major concern for massive structures. Therefore, an active test has been developed to study cracking due to restrained thermal shrinkage. This test is an evolution of the classical restrained shrinkage ring test. It allows to take into account both autogenous and thermal shrinkages. Its principle is to create the thermal strain effects by increasing the temperature of the brass ring (by a fluid circulation) in order to expand it. With this test, the early age cracking due to restrained shrinkage, the influence of reinforcement and construction joints have been experimentally studied. It shows that, as expected, reinforcement leads to an increase of the number of cracks but a decrease of crack widths. Moreover, cracking occurs preferentially at the construction joint.

  3. Of Chains and Rings: Synthetic Strategies and Theoretical Investigations for Tuning the Structure of Silver Coordination Compounds and Their Applications

    Tünde Vig Slenters

    2010-05-01

    Full Text Available Varying the polyethyleneglycol spacer between two (iso-nicotinic groups of the ligand systems, a large structural variety of silver coordination compounds was obtained, starting with zero-dimensional ring systems, via one-dimensional chains, helices and double-helices to two-dimensional polycatenanes. Theoretical calculations help to understand their formation and allow predictions in some cases. These structures can be tuned by careful design of the ligand, the use of solvent and the counter ions, influencing also other important properties such as light stability and solubility. The latter is important in the context of biomedical applications, using silver compounds as antimicrobial agents.

  4. Something old, something new : Update of the 2009 and 2013 ABCD guidelines on prevention and management of feline infectious diseases

    Möstl, Karin; Addie, Diane D; Boucraut-Baralon, Corine; Egberink, Herman; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Hosie, Margaret J; Lloret, Albert; Lutz, Hans; Marsilio, Fulvio; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Horzinek, Marian C

    2015-01-01

    OVERVIEW: The ABCD has published 34 guidelines in two Special Issues of the Journal of Feline Medicine and Surgery (JFMS): the first in July 2009 (Volume 11, Issue 7, pages 527-620) and the second in July 2013 (Volume 15, Issue 7, pages 528-652). The present article contains updates and new informat

  5. Pathogenicity of novel ABCD1 variants: The need for biochemical testing in the era of advanced genetics.

    Schackmann, Martin J A; Ofman, Rob; van Geel, Björn M; Dijkstra, Inge M E; van Engelen, Klaartje; Wanders, Ronald J A; Engelen, Marc; Kemp, Stephan

    2016-06-01

    X-linked adrenoleukodystrophy (ALD), a progressive neurodegenerative disease, is caused by mutations in ABCD1 and characterized by very-long-chain fatty acids (VLCFA) accumulation. In male patients, an increased plasma VLCFA levels in combination with a pathogenic mutation in ABCD1 confirms the diagnosis. Recent studies have shown that many women with ALD also develop myelopathy. Correct diagnosis is important for management including genetic counseling. Diagnosis in women can only be confirmed when VLCFA levels are elevated or when a known pathogenic ABCD1 mutation is identified. However, in 15-20% of women with ALD VLCFA plasma levels are not elevated. Demonstration that a novel sequence variant is pathogenic can be a challenge when VLCFA levels are in the normal range. Here we report two women with a clinical presentation compatible with ALD, an ABCD1 variation (p.Arg17His and p.Ser358Pro) of unknown significance, but with normal VLCFA levels. We developed a diagnostic test that is based on generating clonal cell lines that express only one of the two alleles. Subsequent biochemical studies enabled us to show that the two sequence variants were not pathogenic, thereby excluding the diagnosis ALD in these women. We conclude that the clonal approach is an important addition to the existing diagnostic array. PMID:27067449

  6. Optimization of a guard ring structure in Geiger-mode avalanche photodiodes fabricated at National NanoFab Center

    Lim, K. T.; Kim, H.; Cho, M.; Kim, Y.; Kim, C.; Kim, M.; Lee, D.; Kang, D.; Yoo, H.; Park, K.; Sul, W. S.; Cho, G.

    2016-01-01

    A typical Geiger-mode avalanche photodiode (G-APD) contains a guard ring that protects the structure from having an edge breakdown due to the lowering of electric fields at junction curvatures. In this contribution, G-APDs with a virtual guard ring (vGR) merged with n-type diffused guard ring (nGR) in various sizes were studied to find the optimal design for G-APDs fabricated at National NanoFab Center (NNFC) . The sensors were fabricated via a customized CMOS process with a micro-cell size of 65× 65 μm2 on a 200 mm p-type epitaxial layer wafer. I-V characteristic curves for proposed structures were measured on a wafer-level with an auto probing system and plotted together to compare their performance. A vGR width of 1.5 μm and a nGR width of 1.5 μm with an overlapping between vGR and nGR of 1.5 μm showed the lowest leakage current before the breakdown voltage while suppressing the edge breakdown. Furthermore, the current level of the lowest-leakage-current structure was as low as that of only vGR with a width of 2.0 μm, indicating that the structure is also area efficient. Based on these results, the design with vGR, nGR, and OL with width of 1.5 μm is determined to be the optimal structure for G-APDs fabricated at NNFC.

  7. Optimization of a guard ring structure in Geiger-mode avalanche photodiodes fabricated at National NanoFab Center

    A typical Geiger-mode avalanche photodiode (G-APD) contains a guard ring that protects the structure from having an edge breakdown due to the lowering of electric fields at junction curvatures. In this contribution, G-APDs with a virtual guard ring (vGR) merged with n-type diffused guard ring (nGR) in various sizes were studied to find the optimal design for G-APDs fabricated at National NanoFab Center (NNFC) . The sensors were fabricated via a customized CMOS process with a micro-cell size of 65×65μm2 on a 200 mm p-type epitaxial layer wafer. I-V characteristic curves for proposed structures were measured on a wafer-level with an auto probing system and plotted together to compare their performance. A vGR width of 1.5 μm and a nGR width of 1.5 μm with an overlapping between vGR and nGR of 1.5 μm showed the lowest leakage current before the breakdown voltage while suppressing the edge breakdown. Furthermore, the current level of the lowest-leakage-current structure was as low as that of only vGR with a width of 2.0 μm, indicating that the structure is also area efficient. Based on these results, the design with vGR, nGR, and OL with width of 1.5 μm is determined to be the optimal structure for G-APDs fabricated at NNFC

  8. Structure of a Glomulin-RBX1-CUL1 complex: inhibition of a RING E3 ligase through masking of its E2-binding surface

    Duda, David M.; Olszewski, Jennifer L.; Tron, Adriana E.; Hammel, Michal; Lambert, Lester J; Waddell, M. Brett; Mittag, Tanja; DeCaprio, James A.; Schulman, Brenda A.

    2012-01-01

    The ~300 human Cullin-RING ligases (CRLs) are multisubunit E3s in which a RING protein, either RBX1 or RBX2, recruits an E2 to catalyze ubiquitination. RBX1-containing CRLs also can bind Glomulin (GLMN), which binds RBX1’s RING domain, regulates the RBX1-CUL1-containing SCFFBW7 complex, and is disrupted in the disease Glomuvenous Malformation. Here we report the crystal structure of a complex between GLMN, RBX1, and a fragment of CUL1. Structural and biochemical analyses reveal that GLMN adop...

  9. Ultra-Sensitive Chip-Based Photonic Temperature Sensor Using Ring Resonator Structures

    Xu, Haitan; Hafezi, Mohammad; Fan, J.; Taylor, J. M.; Strouse, G. F.; Ahmed, Zeeshan

    2013-01-01

    Resistance thermometry provides a time-tested method for taking temperature measurements. However, fundamental limits to resistance-based approaches has produced considerable interest in developing photonic temperature sensors to leverage advances in frequency metrology and to achieve greater mechanical and environmental stability. Here we show that silicon-based optical ring resonator devices can resolve temperature differences of 1 mK using the traditional wavelength scanning methodology. A...

  10. Coherence and Polarization of Polarization Speckle Generated by Depolarizers and Their Changes through Complex ABCD Matrix

    Ma, Ning; Hanson, Steen Grüner; Lee, Tim K.;

    2015-01-01

    Recent research work on speckle patterns indicates a variation of the polarization state during propagation and its nonuniformly spatial distribution. The preliminary step for the investigation of this polarization speckle is the generation of the corresponding field. In this paper, a kind of...... special depolarizer: the random roughness birefringent screen (RRBS) is introduced to meet this requirement. The statistical properties of the field generated by the depolarizer is investigated and illustrated in terms of the 2x2 beam coherence and polarization matrix (BCPM) with the corresponding degree...... of coherence (DoC). and degree of polarization (DoP) P. The changes of the coherence and polarization when the speckle field propagates through any optical system are analysed within the framework of the complex ABCD-matrix theory....

  11. Double-bosonization and Majid’s conjecture, (I): Rank-inductions of ABCD

    Majid developed in [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151–192 (1999)] the double-bosonization theory to construct Uq(g) and expected to generate inductively not just a line but a tree of quantum groups starting from a node. In this paper, the authors confirm Majid’s first expectation (see p. 178 [S. Majid, Math. Proc. Cambridge Philos. Soc. 125, 151–192 (1999)]) through giving and verifying the full details of the inductive constructions of Uq(g) for the classical types, i.e., the ABCD series. Some examples in low ranks are given to elucidate that any quantum group of classical type can be constructed from the node corresponding to Uq(sl2)

  12. Instrument validation for assessing critically ill patients on mechanical ventilation according to the ABCDE

    Percival Vitorino Guimarães

    2015-03-01

    Full Text Available The objective of this study was to validate the content of an instrument aimed at guiding the nursing care provided to patients on artificial respiration. An instrument was created with five indicators, inspired on the mnemonic ABCDE method, used in the Advanced Trauma Life Support course, namely: A – Airway maintenance, with 38 items; B – Breathing and ventilation, 11 items; C – Circulation with hemorrhage control, 16 items; D – Disability/neurologic assessment, 08 items; and E – Exposure and environmental control, 08 items. The Content Validity Index (CVI was used to calculate the degree of agreement among the experts for the general analysis of the instrument and the analysis of the set of items. In conclusion, this instrument works as an assessment tool for patients on artificial respiration, especially when they are in adapted environments to intensive care, as it guides the nurse to observe aspects that may cause harm to the patient.

  13. Sling-on-a-Ring: Structure for an elevator to LEO

    Meulenberg, Andrew

    2015-01-01

    Various proposed space elevators may bypass the financial and environmental limits on rocket technology, but all have their own problems. A Low-Earth-Orbit, LEO, rotovator-based space-elevator version called 'sling-on-a-ring' may overcome them. This mass-lifting system uses the spatial stability of an orbital ring, accessorized for transfer and storage of momentum and electrical power. A high-tensile-strength equatorial circum-terra loop of colossal-carbon tube, CCT, fiber has solar-power and station-keeping units and rotating sling modules. Long sling assemblies, ~600 km, periodically descend into the atmosphere to ~13 km. At perigee, the sling rotational tip velocity almost cancels the orbital-ring velocity relative to Earth surface. Split-second timing detaches a ~10 ton payload from an ordinary aircraft and jerks it into space by sling momentum, with the proven specific strength of CCTs now under development. This system eliminates the immense mass in space of other space-elevator systems, but needs extre...

  14. A giant ring-like structure at 0.78

    Balazs, L G; Hakkila, J E; Horvath, I; Kobori, J; Racz, I; Toth, L V

    2015-01-01

    According to the cosmological principle, Universal large-scale structure is homogeneous and isotropic. The observable Universe, however, shows complex structures even on very large scales. The recent discoveries of structures significantly exceeding the transition scale of 370 Mpc pose a challenge to the cosmological principle. We report here the discovery of the largest regular formation in the observable Universe; a ring with a diameter of 1720 Mpc, displayed by 9 gamma ray bursts (GRBs), exceeding by a factor of five the transition scale to the homogeneous and isotropic distribution. The ring has a major diameter of $43^o$ and a minor diameter of $30^o$ at a distance of 2770 Mpc in the 0.78structure. However, these...

  15. Avaliação do aprendizado dos pacientes sobre a regra do ABCD: um estudo randomizado no sul do Brasil Evaluation of patients’ learning about the ABCD rule: a randomized study in southern Brazil

    Karen Reetz Müller

    2009-12-01

    Full Text Available FUNDAMENTOS: A regra do ABCD é utilizada para orientar médicos, profissionais da saúde e pacientes quanto ao reconhecimento das principais características de lesões cutâneas suspeitas de melanoma. Não há, no Brasil,estudos que validem a utilização da regra do ABCD pelos pacientes após orientações realizadas por dermatologistas. OBJETIVOS: Avaliar o aprendizado da regra do ABCD por pacientes atendidos em centro dermatológico de referência no sul do Brasil. MÉTODOS: Estudo randomizado com 80 pacientes ambulatoriais de ambos os sexos, com 12 anos ou mais. Foram avaliados: grau de escolaridade, renda mensal e acesso aos meios de comunicação. O grupo de intervenção recebeu orientações sobre o emprego da regra do ABCD, ao passo que o grupo-controle não recebeu. Ambos os grupos foram avaliados quanto às suas respostas em três momentos (basal, fora do consultório e no consultório, 15 dias após em painel de fotografias. O nível de significância utilizado foi o p Background: the ABCD rule is used to guide physicians, health care professionals and patients to recognize the main characteristics of suspicious skin lesions for melanoma. In Brazil there are no studies to validate the use of the ABCD rule by patients after instructions given by dermatologists. Objectives: to evaluate the learning of the ABCD rule by patients at a dermatology center of reference in the Southern region of Brazil. Methods: a randomized study, with 80 outpatients. The following were evaluated: sex, age, level of schooling, monthly income and access to means of communication. The intervention group received instructions regarding the use of the ABCD rule and the control group did not. Both groups were evaluated at three points in time (baseline; outside the office; and in the doctor's office, 15 days later regarding their answers about a panel of photographs. The level of significance used was p < 0.05 and a power of 0.80. Results: the group that

  16. Black rings

    A black ring is a five-dimensional black hole with an event horizon of topology S1 x S2. We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  17. techniques related to the fabrication of silicon and germanium guard-ring structural detectors and their use in nuclear physics

    The elements of the position sensitive semiconductor detectors are separated by grooves that must have high resistance and must be also time stable, independently of the environment where the detector is placed. Therefore, one theme of study inherent to the fabrication of position sensitive detectors is the detectors properties. Si (Li), Si (Hp) and Ge (Hp) guard ring structural detectors have been developed by two different methods, ion implementation combined with photolithography and plasma etching, and metal evaporation with the use of a mask. The application of new passivation techniques on these detectors led to successive reduction of their reverse currents, which made possible to get the desired final stable characteristics

  18. Collectivity of plasmonic excitations in small sodium clusters with ring and linear structures

    The collectivity of the electronic motion in finite systems is studied by using both the linear response density functional theory (LRDFT) and the collectivity index defined by the transition density matrix. We demonstrate a collectivity analysis on the size-dependent peaks of electronic excitations of small sodium clusters (rings and linear chains). We find the excitation-mode dependence of the collectivity and large collectivities for the higher-energy plasmonic excitations. The collectivity analysis also clarifies the existence of the nondipolar collective motion at the energies very close to the higher-energy plasmonic excitations. The importance of the nondipolar motion is pointed out in light of nano-optics.

  19. Ultra-Sensitive Chip-Based Photonic Temperature Sensor Using Ring Resonator Structures

    Xu, Haitan; Fan, J; Taylor, J M; Strouse, G F; Ahmed, Zeeshan

    2013-01-01

    Resistance thermometry provides a time-tested method for taking temperature measurements. However, fundamental limits to resistance-based approaches has produced considerable interest in developing photonic temperature sensors to leverage advances in frequency metrology and to achieve greater mechanical and environmental stability. Here we show that silicon-based optical ring resonator devices can resolve temperature differences of 1 mK using the traditional wavelength scanning methodology. An even lower noise floor of 80 microkelvin for measuring temperature difference is achieved in the side-of-fringe, constant power mode measurement.

  20. Structural and spectroscopic investigation on a new potentially bioactive di-hydrazone containing thiophene heterocyclic rings

    Nogueira, Vanessa de S.; Ramalho Freitas, Maria Clara; Cruz, Wellington S.; Ribeiro, Tatiana S.; Resende, Jackson A. L. C.; Rey, Nicolás A.

    2016-02-01

    Hydrazones and several substituted hydrazones are associated with a broad spectrum of biological activities, as well as compounds containing the thiophene ring. In this context, a novel di-hydrazone derived from 2-thiophenecarboxylic acid hydrazide was synthesized and completely characterized by elemental analysis, XRD, FT-IR, Raman and UV-Vis spectroscopies, thermogravimetry, 1H NMR, 1H-1H COSY and 1H-1H ROESY. A preliminary in silico pharmacological evaluation was also performed in order to assess the performance of the new compound regarding some molecular properties relevant for a drug's pharmacokinetics in the human body.

  1. Design and performance analysis of delay insensitive multi-ring structures

    Sparsø, Jens; Staunstrup, Jørgen

    A set of simple design and performance analysis techniques that have been successfully used to design a number of nontrivial delay insensitive circuits is described. Examples are building blocks for digital filters and a vector multiplier using a serial-parallel multiply and accumulate algorithm....... The vector multiplier circuit has been laid out, submitted for fabrication and successfully tested. Throughout the analysis elements from this design are used to illustrate the design and performance analysis techniques. The design technique is based on a data flow approach using pipelines and rings...

  2. Two-component secular gravitational instability in a protoplanetary disk: A possible mechanism for creating ring-like structures

    Takahashi, Sanemichi Z.; Inutsuka, Shu-ichiro, E-mail: takahashi.sanemichi@a.mbox.nagoya-u.ac.jp, E-mail: inutsuka@nagoya-u.jp, E-mail: sanemichi@tap.scphys.kyoto-u.ac.jp [Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)

    2014-10-10

    The instability in protoplanetary disks due to gas-dust friction and self-gravity of gas and dust is investigated using linear analysis. In the case where the dust-to-gas ratio is enhanced and turbulence is weak, the instability grows, even in gravitationally stable disks, on a timescale of order 10{sup 4-5} yr at a radius of order 100 AU. If we ignore the dynamical feedback from dust grains in the gas equation of motion, the instability reduces to the so-called ''secular gravitational instability'', which was investigated previously to be an instability of dust in a fixed background gas flow. In this work, we solve the equations of motion for both gas and dust consistently and find that long-wavelength perturbations are stable, in contrast to the secular gravitational instability in the simplified treatment. This may indicate that we should not neglect small terms in the equation of motion if the growth rate is small. The instability is expected to form ring structures in protoplanetary disks. The width of the ring formed at a radius of 100 AU is a few tens of AU. Therefore, the instability is a candidate for the formation mechanism of observed ring-like structures in disks. Another aspect of the instability is the accumulation of dust grains, and hence the instability may play an important role in the formation of planetesimals, rocky protoplanets, and cores of gas giants located at radii ∼100 AU. If these objects survive the dispersal of the gaseous component of the disk, they may be the origin of debris disks.

  3. Synthesis, Structure Optimization and Antifungal Screening of Novel Tetrazole Ring Bearing Acyl-Hydrazones

    Manzoor A. Malik

    2012-08-01

    Full Text Available Azoles are generally fungistatic, and resistance to fluconazole is emerging in several fungal pathogens. In an attempt to find novel azole antifungal agents with improved activity, a series of tetrazole ring bearing acylhydrazone derivatives were synthesized and screened for their in vitro antifungal activity. The mechanism of their antifungal activity was assessed by studying their effect on the plasma membrane using flow cytometry and determination of the levels of ergosterol, a fungal-specific sterol. Propidium iodide rapidly penetrated a majority of yeast cells when they were treated with the synthesized compounds at concentrations just above MIC, implying that fungicidal activity resulted from extensive lesions of the plasma membrane. Target compounds also caused a considerable reduction in the amount of ergosterol. The results also showed that the presence and position of different substituents on the phenyl ring of the acylhydrazone pendant seem to play a role on the antifungal activity as well as in deciding the fungistatic and fungicidal nature of the compounds.

  4. Transformation of InAs islands to quantum ring structures by metalorganic vapor phase epitaxy

    The transformation of InAs islands to quantum rings (QRs) by metalorganic vapor phase epitaxy is investigated. After covering the InAs islands with a thin GaAs partial capping layer and annealing under tertiarybutylarsine (TBAs) flow, ring-shaped nanostructures with a density of 107-109 cm-2 are obtained at 500-600 deg. C. The effects of the growth temperature, annealing process and thickness of the partial capping layer are studied. Optimum values for the annealing time and the partial capping layer thickness were found to be 60-120 s and 0.5-2.0 nm, respectively. Low temperature photoluminescence (PL) emission peaks from islands and QRs grown at 500 deg. C are observed at 1.04 eV and 1.22 eV, respectively. The annealing temperature affected the QR evolution and the PL emission from the QRs due to the temperature dependence of the diffusion rate of indium atoms

  5. Transformation of InAs islands to quantum ring structures by metalorganic vapor phase epitaxy

    Aierken, A; Hakkarainen, T; Riikonen, J; Sopanen, M [Department of Micro and Nanosciences, Micronova, Helsinki University of Technology, PO Box 3500, FIN-02015 TKK (Finland)], E-mail: abuduwayiti.aierken@tkk.fi

    2008-06-18

    The transformation of InAs islands to quantum rings (QRs) by metalorganic vapor phase epitaxy is investigated. After covering the InAs islands with a thin GaAs partial capping layer and annealing under tertiarybutylarsine (TBAs) flow, ring-shaped nanostructures with a density of 10{sup 7}-10{sup 9} cm{sup -2} are obtained at 500-600 deg. C. The effects of the growth temperature, annealing process and thickness of the partial capping layer are studied. Optimum values for the annealing time and the partial capping layer thickness were found to be 60-120 s and 0.5-2.0 nm, respectively. Low temperature photoluminescence (PL) emission peaks from islands and QRs grown at 500 deg. C are observed at 1.04 eV and 1.22 eV, respectively. The annealing temperature affected the QR evolution and the PL emission from the QRs due to the temperature dependence of the diffusion rate of indium atoms.

  6. Use of silica-encapsulated Pseudomonas sp. strain NCIB 9816-4 in biodegradation of novel hydrocarbon ring structures found in hydraulic fracturing waters.

    Aukema, Kelly G; Kasinkas, Lisa; Aksan, Alptekin; Wackett, Lawrence P

    2014-08-01

    The most problematic hydrocarbons in hydraulic fracturing (fracking) wastewaters consist of fused, isolated, bridged, and spiro ring systems, and ring systems have been poorly studied with respect to biodegradation, prompting the testing here of six major ring structural subclasses using a well-characterized bacterium and a silica encapsulation system previously shown to enhance biodegradation. The direct biological oxygenation of spiro ring compounds was demonstrated here. These and other hydrocarbon ring compounds have previously been shown to be present in flow-back waters and waters produced from hydraulic fracturing operations. Pseudomonas sp. strain NCIB 9816-4, containing naphthalene dioxygenase, was selected for its broad substrate specificity, and it was demonstrated here to oxidize fundamental ring structures that are common in shale-derived waters but not previously investigated with this or related enzymes. Pseudomonas sp. NCIB 9816-4 was tested here in the presence of a silica encasement, a protocol that has previously been shown to protect bacteria against the extremes of salinity present in fracking wastewaters. These studies demonstrate the degradation of highly hydrophobic compounds by a silica-encapsulated model bacterium, demonstrate what it may not degrade, and contribute to knowledge of the full range of hydrocarbon ring compounds that can be oxidized using Pseudomonas sp. NCIB 9816-4. PMID:24907321

  7. Crystallization and preliminary x-ray crystallography data of the dimer of tetramer s (abcd)2 of extracellular hemoglobin from Glossoscolex paulistus in cyano met form

    Full text. The extracellular hemoglobin from Glossoscolex paulistus has a molecular weight near to 3.1 x 106 Da and a structure organized in a double-layered hexagonal oligomer. The tertiary complex of dimer of tetramers (abcd)2 was obtained by chromography in Sephadex G-200, in pH 9.0, as a result of alkaline dissociation. Aiming to obtain a better understanding of the oligomeric structure and specially for the inter subunit interactions the extracellular hemoglobins, we have obtained crystals of dimer of tetramers (abcd)2 of hemoglobin from Glossoscolex and we are studying the in behavior in different conditions of precipitants and pH's. Our goal is to solve the crystal structure in order to characterize, at atomic level, the subunits contacts, heme environment and differences in residues involved in oxygenation in order to understand in this hemoglobin. The crystallization experiments the protein concentration in the cyanomet form was about 10 mg/ml and the experiments were carried out at 180C. The optimal crystallization condition achieved from factorial assays was 10% (w/v). Polyethylene glycol (PEG) 8,000 and 8%(v/v) ethylene glycol in 100 mM HEPES pH 7.5. The optimization of this condition was carried out with the variation of PEG concentrations from 6% up to 10% (by 1% step) and pH between 7.0 and 8.0. A quite critical p-H-dependence has been observed on crystal nucleation, decreasing from pH 7.0, in which the number of microcrystals in higher, up to pH 8.0, in which crystals did not appear even at higher PEG 8,000 (10% w/v). As several structures of hemoglobin from different sources (vertebrate and invertebrates) are available, we hope to solve their structure of hemoglobin from Glossoscolex paulistus by Molecular Replacement, even though the tetramer organization may be different in the earthworm as compared related to other known tetrameric hemoglobin structures. (author)

  8. A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars

    Kestay, Laszlo P.; Jaeger, Windy L.

    2015-01-01

    The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures that were previously embedded in the lava. The “Odessa Craters,” near Odessa, WA, are 50–500-m-wide BRSs that are comprised of discontinuous, concentric outcrops of subvertically-jointed basalt and autointrusive dikes. Detailed field investigation of the Odessa Craters in planform and a cross-sectional exposure of a similar structure above Banks Lake, WA, lead us to propose that BRSs formed by concurrent phreatovolcanism and lava flow inflation. In this model, phreatovolcanic (a.k.a., “rootless”) cones formed on a relatively thin, active lava flow; the lava flow inflated around the cones, locally inverting topography; tensile stresses caused concentric fracturing of the lava crust; lava from within the molten interior of the flow exploited the fractures and buried the phreatovolcanic cones; and subsequent erosive floods excavated the structures. Another population of BRSs near Tokio Station, WA, consists of single-ringed, raised-rimmed structures that are smaller and more randomly distributed than the Odessa Craters. We find evidence for a phreatovolcanic component to the origin as well, and hypothesize that they are either flood-eroded phreatovolcanic cones or Odessa Crater-like BRSs. This work indicates that BRSs are not good analogs to the features on Mars because the martian features are found on the uneroded surfaces. Despite this, the now superseded concepts for BRS formation are useful for understanding the formation of the martian features.

  9. Inorganic glass ceramic slip rings

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  10. The histone chaperones Vps75 and Nap1 form ring-like, tetrameric structures in solution

    Bowman, Andrew; Hammond, Colin M.; Stirling, Andrew; Ward, Richard; Shang, Weifeng; El-Mkami, Hassane; Robinson, David A.; Svergun, Dmitri I.; Norman, David G.; Owen-Hughes, Tom

    2014-01-01

    NAP-1 fold histone chaperones play an important role in escorting histones to and from sites of nucleosome assembly and disassembly. The two NAP-1 fold histone chaperones in budding yeast, Vps75 and Nap1, have previously been crystalized in a characteristic homodimeric conformation. In this study, a combination of small angle X-ray scattering, multi angle light scattering and pulsed electron–electron double resonance approaches were used to show that both Vps75 and Nap1 adopt ring-shaped tetrameric conformations in solution. This suggests that the formation of homotetramers is a common feature of NAP-1 fold histone chaperones. The tetramerisation of NAP-1 fold histone chaperones may act to shield acidic surfaces in the absence of histone cargo thus providing a ‘self-chaperoning’ type mechanism. PMID:24688059

  11. Electronic structure of GaAs/AlGaAs quantum double rings in lateral electric field

    Y.Yao; T.Ochiai; T.Mano; T.Kuroda; T.Noda; N.Koguchi; K.Sakoda

    2009-01-01

    A three-dimensional model of GaAs/A1GaAs quantum double rings in the lateral static electric field is investigated theoretically.The eigenvalue problem with the effective-mass approximation is solved by means of the finite-element method.The energy levels and wave functions of quantum-confined electrons and heavy holes are obtained and show an agreement with our previous theoretical and experimental studies.It is shown in the approximation of neglecting the Coulomb attraction between the electron and heavy hole that a relatively large Stark shift of exciton emission of 4 meV is attainable with an applied electric field of 0.7 kV/cm.

  12. Fano resonance and wave transmission through a chain structure with an isolated ring composed of defects

    We consider a discrete model that describes a linear chain of particles coupled to an isolated ring composed of N defects. This simple system can be regarded as a generalization of the familiar Fano-Anderson model. It can be used to model discrete networks of coupled defect modes in photonic crystals and simple waveguide arrays in two-dimensional lattices. The analytical result of the transmission coefficient is obtained, along with the conditions for perfect reflections and transmissions due to either destructive or constructive interferences. Using a simple example, we further investigate the relationship between the resonant frequencies and the number of defects N, and study how to affect the numbers of perfect reflections and transmissions. In addition, we demonstrate how these resonance transmissions and refections can be tuned by one nonlinear defect of the network that possesses a nonlinear Kerr-like response. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. Monte Carlo simulation for thermal assisted reversal process of micro-magnetic torus ring with bistable closure domain structure

    Terashima, Kenichi; Suzuki, Kenji; Yamaguchi, Katsuhiko

    2016-04-01

    Monte Carlo simulations were performed for temperature dependences of closure domain parameter for a magnetic micro-torus ring cluster under magnetic field on limited temperature regions. Simulation results show that magnetic field on tiny limited temperature region can reverse magnetic closure domain structures when the magnetic field is applied at a threshold temperature corresponding to intensity of applied magnetic field. This is one of thermally assisted switching phenomena through a self-organization process. The results show the way to find non-wasteful pairs between intensity of magnetic field and temperature region for reversing closure domain structure by temperature dependence of the fluctuation of closure domain parameter. Monte Carlo method for this simulation is very valuable to optimize the design of thermally assisted switching devices.

  14. Token Ring Project

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  15. Increasing access to dental care for medicaid preschool children: the Access to Baby and Child Dentistry (ABCD) program.

    Grembowski, D; Milgrom, P M

    2000-01-01

    OBJECTIVE: Washington State's Access to Baby and Child Dent stry (ABCD) Program, first implemented in Spokane County in 1995, offers extended dental benefits to participating Medicaid-enrolled children and higher fees for certified providers. This study aimed to determine the program's effect on children's dental utilization and dental fear, and on parent satisfaction and knowledge. METHODS: The study used a posttest-only comparison group design. Trained interviewers conducted telephone inter...

  16. Regulation of Escherichia coli fumarate reductase (frdABCD) operon expression by respiratory electron acceptors and the fnr gene product.

    Jones, H. M.; Gunsalus, R P

    1987-01-01

    The fumarate reductase enzyme complex, encoded by the frdABCD operon, allows Escherichia coli to utilize fumarate as a terminal electron acceptor for anaerobic oxidative phosphorylation. To analyze the expression of fumarate reductase, protein and operon fusions were constructed between the frdA and the lacZ genes and introduced onto the E. coli chromosome at the lambda attachment site. Expression of beta-galactosidase from either fusion was increased 10-fold during anaerobic versus aerobic c...

  17. The AmBulatory Closure Device Percutaneous Intervention (ABCD-PCI) study: a single-center experience

    Falcone, Adam M.; Bose, Rahul; Stoler, Robert C; Kim, Michael; Laible, Emily; Kang, Lucy; Waters, Kim; Dunkerley, Janet; Choi, James W.

    2011-01-01

    The AmBulatory Closure Device Percutaneous Intervention (ABCD-PCI) study is a multicenter randomized prospective controlled trial evaluating the safety of and patient satisfaction with same-day discharge following ambulatory percutaneous intervention with a closure device. This article reviews the findings from a single center, Baylor Jack and Jane Hamilton Heart and Vascular Hospital, from October 2008 through April 2010, with 23 patients in the same-day discharge group and 21 patients in th...

  18. Study protocol: Audit and Best Practice for Chronic Disease Extension (ABCDE Project

    Thompson Sandra

    2008-09-01

    Full Text Available Abstract Background A growing body of international literature points to the importance of a system approach to improve the quality of care in primary health care settings. Continuous Quality Improvement (CQI concepts and techniques provide a theoretically coherent and practical way for primary care organisations to identify, address, and overcome the barriers to improvements. The Audit and Best Practice for Chronic Disease (ABCD study, a CQI-based quality improvement project conducted in Australia's Northern Territory, has demonstrated significant improvements in primary care service systems, in the quality of clinical service delivery and in patient outcomes related to chronic illness care. The aims of the extension phase of this study are to examine factors that influence uptake and sustainability of this type of CQI activity in a variety of Indigenous primary health care organisations in Australia, and to assess the impact of collaborative CQI approaches on prevention and management of chronic illness and health outcomes in Indigenous communities. Methods/design The study will be conducted in 40–50 Indigenous community health centres from 4 States/Territories (Northern Territory, Western Australia, New South Wales and Queensland over a five year period. The project will adopt a participatory, quality improvement approach that features annual cycles of: 1 organisational system assessment and audits of clinical records; 2 feedback to and interpretation of results with participating health centre staff; 3 action planning and goal setting by health centre staff to achieve system changes; and 4 implementation of strategies for change. System assessment will be carried out using a System Assessment Tool and in-depth interviews of key informants. Clinical audit tools include two essential tools that focus on diabetes care audit and preventive service audit, and several optional tools focusing on audits of hypertension, heart disease, renal

  19. Time structure measurement of the storage ring with the time-resolved X-ray excited optical luminescence method at SSRF

    Zhaohong, Zhang; Song, Xue; Lifang, Zheng

    2014-01-01

    Measuring the time structure of the storage ring on the sample spot inside the experimental hutch is a foundational step during the time-resolved experiments using the pulsed synchrotron X-rays with the time structure defined by the storage ring. In this work, the method of time-resolved X-ray excited optical luminescence was designed and implemented to do the measurement. This method is based on the principle of time-correlated single photon counting techniques. The measurement system consists of a spectrometer with a detector of photomultiplier tube, a timing system, a set of Nuclear Instrument Modules and a luminescent material of Zinc Oxide. The measurement was performed on the X-ray absorbed fine structure spectrum beamline at Shanghai Synchrotron Radiation Facility. The results show that this system can be used to measure the time structure of the storage ring with a precision of less than 1 ns.

  20. TCAD Simulations of ATLAS Pixel Guard Ring and Edge Structure for SLHC Upgrade

    Lounis, A; The ATLAS collaboration; Calderini, G; Marchiori, G; Benoit, M; Dinu, N

    2010-01-01

    In this work, the magnitude of the electric field and the depletion inside a simplified two dimensional model of the ATLAS planar pixel sensor for the insertable b-layer and the super-LHC upgrade have been studied. The parameters influencing the breakdown behavior were studied using a finite-element method to solve the drift-diffusion equations coupled to Poisson's equation. Using these models, the number of guard rings, dead edge width and sensor's thickness were modified with respect to the ATLAS actual pixel sensor to investigate their influence on the sensor's depletion at the edge and on its internal electrical field distribution. The goal of the simulation is to establish a model to discriminate between different designs and to select the most optimized to fit the needs in radiation hardness and low material budget of ATLAS inner detector during super-LHC operation. A three defects level model has been implemented in the simulations to study the behavior of such sensors under different level of irradiat...

  1. Ring theory

    Rowen, Louis H

    1991-01-01

    This is an abridged edition of the author's previous two-volume work, Ring Theory, which concentrates on essential material for a general ring theory course while ommitting much of the material intended for ring theory specialists. It has been praised by reviewers:**""As a textbook for graduate students, Ring Theory joins the best....The experts will find several attractive and pleasant features in Ring Theory. The most noteworthy is the inclusion, usually in supplements and appendices, of many useful constructions which are hard to locate outside of the original sources....The audience of non

  2. Shallow Crustal Structure of Chicxulub Impact Crater Imaged With Seismic, Gravity and Magnetotelluric Data: Structure of the Central Uplift and Origin of the Cenotes Ring.

    Campos Enriquez, O.; Chavez Garcia, F.; Cruz Jimenez, H.; Acosta Chang, J.; Takafumi, M.; Arzate, J.; Unsworth, M.; Ramos Lopez, J.

    2002-12-01

    The shallow crustal structure of the onshore portion of the Chicxulub impact structure (Yucatan, Mexico) has been studied with seismic, gravity and MT exploration. A dispersion analysis of Rayleigh waves along a 150-km long, east-west profile allowed to image the shallow Tertiary cover to a depth of 400 m. The thickness of the first layer increases towards the central basin, from less than 100 m immediately outside, to more than 200 m in the terrace zone. The second layer also increases its thickness from about 150 m outside the crater rim, to around 250 m in the vicinity of the rim. At the center of the crater the first layer is again about 100 m thick. The increase in thickness of the first two layers as we approach the sinkhole ring from the exterior of the crater is consistent with the existence of a central basin. The velocity distribution along our profile does not have low-velocity layers. Thus, a low velocity layer observed in the Tertiary cover in a previous study, may be delimited to a ring around the crater center. The inferred inward slope of the two shallow layers immediately outside the central basin correlates with a smooth gravity gradient. A gravity model based in detailed measurements along our profile enable us to associate the fracturing that favored the development of the sink holes at the eastern rim with the ring fracture mapped by offshore seismic line. Finally, preliminary results of ongoing magnetotelluric (MT) studies support the existence of the central structural high.

  3. Spectral shifts of partially coherent radial array beams passing through ABCD optical systems

    Pan, Leilei; Zhang, Bin

    2010-05-01

    The expressions for the spectral intensity of partially coherent Gaussian Schell-model (GSM) radial array beams for both the correlated and uncorrelated superpositions passing through ABCD optical systems have been derived by using the extended Huygens-Fresnel diffraction integral. The effects of the normalized radius R, the number of beamlets N, the spatial coherent parameter of array beamlets β and the optical system parameters on the on-axis and off-axis relative spectral shifts for the two types of superposition have been discussed in detail. The results show that for the correlated superposition, the on-axis spectral intensity in free space and the off-axis spectral intensity on the geometrical focal plane depends on the source spectral density S0( ω), the spatial coherent parameter of array beamlets β, the generalized Fresnel number of the system F, the normalized radius R and the number of beamlets N, whereas the spectral intensity for the uncorrelated superposition is independent of the number of beamlets N. Furthermore, as for on the actual focal plane, the off-axis spectral intensity for the two types of superposition is closely related to N.

  4. Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  5. Multiband one-way polarization conversion in complementary split-ring resonator based structures by combining chirality and tunneling.

    Serebryannikov, Andriy E; Beruete, Miguel; Mutlu, Mehmet; Ozbay, Ekmel

    2015-05-18

    Multiband one-way polarization conversion and strong asymmetry in transmission inspired by it are demonstrated in ultrathin sandwiched structures that comprise two twisted aperture-type arrays of complementary split-ring resonators (CSRRs), metallic mesh, and dielectric layers. The basic features of the resulting mechanism originate from the common effect of chirality and tunneling. The emphasis is put on the (nearly) perfect polarization conversion of linear incident polarization into the orthogonal one and related diodelike asymmetric transmission within multiple narrow bands. Desired polarization conversion can be obtained at several resonances for one of the two opposite incidence directions, whereas transmission is fully blocked for the other one. The resonances, at which the (nearly) perfect conversion takes place, are expected to be inherited from similar structures with parallel, i.e., not rotated CSRR arrays that do not enable chirality and, thus, polarization conversion. It is found that the basic transmission and polarization conversion features and, thus, the dominant physics are rather general, enabling efficient engineering of such structures. The lowest-frequency resonance can be obtained in structures made of conventional materials with total thickness less than λ/50 and up to ten such resonances can correspond to thickness less than λ/20. PMID:26074599

  6. Analysis of the structural integrity of the fuel rod cladding based on ring compression tests

    Due to the reduced amount of material involved and the relatively simple test set-up, Ring Compression Tests (RCT) on fuel rod cladding specimens has become a well-accepted test to determine the conditions resulting in a brittle response on the cladding. Indeed, from its application under LOCA conditions, also it is used under the Spent Fuel Storage and Transportation conditions. Although the RCT may run the involved material through three stages: elastic, elasto-plastic and damage propagation and relevant information on material properties may be obtained, the non-homogenous stress and strain conditions makes the analysis of the test results, difficult. Even though, some efforts have successfully provided key cladding performance parameters such as the fracture toughness. Others approaches use the RCT as a screening test to determine conditions resulting in a Ductile-to-Brittle transition based on a selected criterion. This paper proposes a criterion from the RCT results based on first principles to address cladding ductility under the pinch loads that occurs during the transportation accident of the cask horizontal drop. The insights gained from a mechanical analysis of the RCT are applied on a number of RCT performed on unirradiated pre-hydrided specimens. Besides, RCT results performed on BWR irradiated cladding with several degrees of radial reorientation of the hydrides, imposed by a previous creep test, are also analyzed following the same approach. Based on this analysis and the expected diametric displacement, allowed by the end of irradiation pellet to clad gap and the outward cladding creep during drying and storage in a dry cask, a criterion is determined. (author)

  7. Solvent micro-evaporation and concentration gradient synergistically induced crystallization of poly(L-lactide) and ring banded supra-structures with radial periodic variation of thickness

    Huang, Shaoyong; Li, Hongfei; Wen, Huiying;

    2014-01-01

    -structures with radial periodic variation of thickness were obtained, which were induced by micro-evaporation of solvents and concentration gradient of PLLA. The ring banded morphologies consisted of multilayer lamellar crystals, which is a manifestation of alternating ridge and valley bands of periodic variation...... of thicknesses along the radial direction. The formation of the ring banded supra-structures is associated with diffusion and crystal growth induced periodic variation of concentration gradient, which is attributed to diffusion-related rhythmic growth and the competition between diffusion of polymer...

  8. Planetary Rings

    Gordon, M. K.; Araki, S.; Black, G. J.; Bosh, A. S.; Brahic, A.; Brooks, S. M.; Charnoz, S.; Colwell, J. E.; Cuzzi, J. N.; Dones, L.; Durisen, R. H.; Esposito, L. W.; Ferrari, C.; Festou, M.; French, R. G.; Giuliatti-Winter, S. M.; Graps, A. L.; Hamilton, D. P.; Horanyi, M.; Karjalainen, R. M.; Krivov, A. V.; Krueger, H.; Larson, S. M.; Levison, H. F.; Lewis, M. C.; Lissauer, J. J.; Murray, C. D.; Namouni, F.; Nicholson, P. D.; Olkin, C. B.; Poulet, F.; Rappaport, N. J.; Salo, H. J.; Schmidt, J.; Showalter, M. R.; Spahn, F.; Spilker, L. J.; Srama, R.; Stewart, G. R.; Yanamandra-Fisher, P.

    2002-08-01

    The past two decades have witnessed dramatic changes in our view and understanding of planetary rings. We now know that each of the giant planets in the Solar System possesses a complex and unique ring system. Recent studies have identified complex gravitational interactions between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto, or collisions between, parent bodies. Yet, as far as we have come, our understanding is far from complete. The fundamental questions confronting ring scientists at the beginning of the twenty-first century are those regarding the origin, age and evolution of the various ring systems, in the broadest context. Understanding the origin and age requires us to know the current ring properties, and to understand the dominant evolutionary processes and how they influence ring properties. Here we discuss a prioritized list of the key questions, the answers to which would provide the greatest improvement in our understanding of planetary rings. We then outline the initiatives, missions, and other supporting activities needed to address those questions, and recommend priorities for the coming decade in planetary ring science.

  9. Dual curved photonic crystal ring resonator based channel drop filter using two-dimensional photonic crystal structure

    Chhipa, Mayur Kumar; Dusad, Lalit Kumar

    2016-05-01

    In this paper channel drop filter (CDF) is designed using dual curved photonic crystal ring resonator (PCRR). The photonic band gap (PBG) is calculated by plane wave expansion (PWE) method and the photonic crystal (PhC) based on two dimensional (2D) square lattice periodic arrays of silicon (Si) rods in air structure have been investigated using finite difference time domain (FDTD) method. The number of rods in Z and X directions is 21 and 20 respectively with lattice constant 0.540 nm and rod radius r = 0.1 µm. The channel drop filter has been optimized for telecommunication wavelengths λ = 1.591 µm with refractive indices 3.533. In the designed structure further analysis is also done by changing whole rods refractive index and it has been observed that this filter may be used for filtering several other channels also. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm2.

  10. Out-of-plane (SH) soil-structure interaction: a shear wall with rigid and flexible ring foundation

    Le, Thang; Lee, Vincent W.; Luo, Hao

    2016-02-01

    Soil-structure interaction (SSI) of a building and shear wall above a foundation in an elastic half-space has long been an important research subject for earthquake engineers and strong-motion seismologists. Numerous papers have been published since the early 1970s; however, very few of these papers have analytic closed-form solutions available. The soil-structure interaction problem is one of the most classic problems connecting the two disciplines of earthquake engineering and civil engineering. The interaction effect represents the mechanism of energy transfer and dissipation among the elements of the dynamic system, namely the soil subgrade, foundation, and superstructure. This interaction effect is important across many structure, foundation, and subgrade types but is most pronounced when a rigid superstructure is founded on a relatively soft lower foundation and subgrade. This effect may only be ignored when the subgrade is much harder than a flexible superstructure: for instance a flexible moment frame superstructure founded on a thin compacted soil layer on top of very stiff bedrock below. This paper will study the interaction effect of the subgrade and the superstructure. The analytical solution of the interaction of a shear wall, flexible-rigid foundation, and an elastic half-space is derived for incident SH waves with various angles of incidence. It found that the flexible ring (soft layer) cannot be used as an isolation mechanism to decouple a superstructure from its substructure resting on a shaking half-space.