WorldWideScience

Sample records for ring system forms

  1. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  2. Evidence for Quantisation in Planetary Ring Systems

    OpenAIRE

    WAYTE, RICHARD

    2017-01-01

    Absolute radial positions of the main features in Saturn's ring system have been calculated by adapting the quantum theory of atomic spectra. Fine rings superimposed upon broad rings are found to be covered by a harmonic series of the form N α A(r)1/2, where N and A are integers. Fourier analysis of the ring system shows that the spectral amplitude fits a response profile which is characteristic of a resonant system. Rings of Jupiter, Uranus and Neptune also obey the same rules. Involvement o...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. New Main Ring control system

    International Nuclear Information System (INIS)

    Seino, K.; Anderson, L.; Ducar, R.; Franck, A.; Gomilar, J.; Hendricks, B.; Smedinghoff, J.

    1990-03-01

    The Fermilab Main Ring control system has been operational for over sixteen years. Aging and obsolescence of the equipment make the maintenance difficult. Since the advent of the Tevatron, considerable upgrades have been made to the controls of all the Fermilab accelerators except the Main Ring. Modernization of the equipment and standardization of the hardware and software have thus become inevitable. The Tevatron CAMAC serial system has been chosen as a basic foundation in order to make the Main Ring control system compatible with the rest of the accelerator complex. New hardware pieces including intelligent CAMAC modules have been designed to satisfy unique requirements. Fiber optic cable and repeaters have been installed in order to accommodate new channel requirements onto the already saturated communication medium system. 8 refs., 2 figs

  5. Planetary ring systems properties, structures, and evolution

    CERN Document Server

    Murray, Carl D

    2018-01-01

    Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

  6. Ring resonator systems to perform optical communication enhancement using soliton

    CERN Document Server

    Amiri, Iraj Sadegh

    2014-01-01

    The title explain new technique of secured and high capacity optical communication signals generation by using the micro and nano ring resonators. The pulses are known as soliton pulses which are more secured due to having the properties of chaotic and dark soliton signals with ultra short bandwidth. They have high capacity due to the fact that ring resonators are able to generate pulses in the form of solitons in multiples and train form. These pulses generated by ring resonators are suitable in optical communication due to use the compact and integrated rings system, easy to control, flexibi

  7. Single-chip ring resonator-based 1 x 8 optical beam forming network in CMOS-compatible waveguide technology

    NARCIS (Netherlands)

    Zhuang, L.; Roeloffzen, C.G.H.; Heideman, Rene; Borreman, A.; Meijerink, Arjan; van Etten, Wim

    2007-01-01

    Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in optical beam forming networks (OBFNs) for phased array antenna systems. Delay and splitting/combining elements can be integrated on a single optical chip to form an OBFN. A state-of-the-art ring resonator-

  8. Design of a ring resonator-based optical beam forming network for phased array receive antennas

    NARCIS (Netherlands)

    van 't Klooster, J.W.J.R.; Roeloffzen, C.G.H.; Meijerink, Arjan; Zhuang, L.; Marpaung, D.A.I.; van Etten, Wim; Heideman, Rene; Leinse, Arne; Schippers, H.; Verpoorte, J.; Wintels, M.

    2008-01-01

    A novel squint-free ring resonator-based optical beam forming network (OBFN) for phased array antennas (PAA) is proposed. It is intended to provide broadband connectivity to airborne platforms via geostationary satellites. In this paper, we present the design of the OBFN and its control system. Our

  9. APS storage ring vacuum system performance

    International Nuclear Information System (INIS)

    Noonan, J.R.; Gagliano, J.; Goeppner, G.A.

    1997-01-01

    The Advanced Photon Source (APS) storage ring was designed to operated with 7-GeV, 100-mA positron beam with lifetimes > 20 hours. The lifetime is limited by residual gas scattering and Touschek scattering at this time. Photon-stimulated desorption and microwave power in the rf cavities are the main gas loads. Comparison of actual system gas loads and design calculations will be given. In addition, several special features of the storage ring vacuum system will be presented

  10. CORRECTION SYSTEMS UPGRADE FOR THE SNS RING

    International Nuclear Information System (INIS)

    PAPAPHILIPPOU, Y.; GARDNER, C.J.; LEE, Y.Y.; WEI, J.

    2001-01-01

    In view of the changes in the design of the SNS ring from the original FODO lattice [l] to the 220m hybrid lattice [2] and finally 1.3GeV compatible 248m ring [3], complementary studies have been undertaken, in order to upgrade its correction packages. We review the evolution of the correction systems and present the accelerator physics studies for the adopted schemes and powering plan

  11. Lectures on algebraic system theory: Linear systems over rings

    Science.gov (United States)

    Kamen, E. W.

    1978-01-01

    The presentation centers on four classes of systems that can be treated as linear systems over a ring. These are: (1) discrete-time systems over a ring of scalars such as the integers; (2) continuous-time systems containing time delays; (3) large-scale discrete-time systems; and (4) time-varying discrete-time systems.

  12. The Conversion of Wiswesser Line Notations to Ring Codes. I. The Conversion of Ring Systems

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

    The computerized conversion of Wiswesser Line Notations to Ring Codes, using a two-part approach, and the set of computer programs generated for the conversion of ring systems are described. (9 references) (Author)

  13. STAR CLUSTERS IN A NUCLEAR STAR FORMING RING: THE DISAPPEARING STRING OF PEARLS

    Energy Technology Data Exchange (ETDEWEB)

    Väisänen, Petri; Barway, Sudhanshu; Randriamanakoto, Zara, E-mail: petri@saao.ac.za [South African Astronomical Observatory, P.O. Box 9 Observatory, Cape Town (South Africa)

    2014-12-20

    An analysis of the star cluster population in a low-luminosity early-type galaxy, NGC 2328, is presented. The clusters are found in a tight star forming nuclear spiral/ring pattern and we also identify a bar from structural two-dimensional decomposition. These massive clusters are forming very efficiently in the circumnuclear environment and they are young, possibly all less than 30 Myr of age. The clusters indicate an azimuthal age gradient, consistent with a ''pearls-on-a-string'' formation scenario, suggesting bar-driven gas inflow. The cluster mass function has a robust down turn at low masses at all age bins. Assuming clusters are born with a power-law distribution, this indicates extremely rapid disruption at timescales of just several million years. If found to be typical, it means that clusters born in dense circumnuclear rings do not survive to become old globular clusters in non-interacting systems.

  14. STAR CLUSTERS IN A NUCLEAR STAR FORMING RING: THE DISAPPEARING STRING OF PEARLS

    International Nuclear Information System (INIS)

    Väisänen, Petri; Barway, Sudhanshu; Randriamanakoto, Zara

    2014-01-01

    An analysis of the star cluster population in a low-luminosity early-type galaxy, NGC 2328, is presented. The clusters are found in a tight star forming nuclear spiral/ring pattern and we also identify a bar from structural two-dimensional decomposition. These massive clusters are forming very efficiently in the circumnuclear environment and they are young, possibly all less than 30 Myr of age. The clusters indicate an azimuthal age gradient, consistent with a ''pearls-on-a-string'' formation scenario, suggesting bar-driven gas inflow. The cluster mass function has a robust down turn at low masses at all age bins. Assuming clusters are born with a power-law distribution, this indicates extremely rapid disruption at timescales of just several million years. If found to be typical, it means that clusters born in dense circumnuclear rings do not survive to become old globular clusters in non-interacting systems

  15. RF SYSTEM FOR THE SNS ACCUMULATOR RING

    International Nuclear Information System (INIS)

    BLASKIEWICZ, M.; BRENNAN, J.M.; BRODOWSKI, J.; DELONG, J.; METH, M.; SMITH, K.; ZALTSMAN, A.

    2001-01-01

    During accumulation the RF beam current in the spallation neutron source ring rises from 0 to 50 amperes. A clean, 250 nanosecond gap is needed for the extraction kicker risetime. Large momentum spread and small peak current are needed to prevent instabilities and stopband related losses. A robust RF system meeting these requirements has been designed

  16. Ring resonator-based single-chip 1x8 optical beam forming network in LPCVD waveguide technology

    NARCIS (Netherlands)

    Zhuang, L.; Roeloffzen, C.G.H.; Heideman, Rene; Borreman, A.; Meijerink, Arjan; van Etten, Wim; Koonen, A.M.J.; Leijtens, X.J.M.; van den Boom, H.P.A.; Verdurmen, E.J.M.; Molina Vázquez, J.

    2006-01-01

    Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in beam forming networks (BFNs) for phased array antenna systems. Delay and splitting/combining elements can be integrated on a single optical chip to form an OBFN. A state-of-the-art 1×8 OBFN chip has been

  17. Beam position monitor system for storage rings

    International Nuclear Information System (INIS)

    Nakamura, M.; Hinkson, J.A.

    1985-05-01

    Beam position monitors (BPM) for synchrotron light storage rings usually consist of beam pickup electrodes, coaxial relays and a narrowband receiver. While accurate, these systems are slow and of limited use in the commissioning of an accelerator. A beam position monitor is described which is intended to be a principal diagnostic during debug and routine running of a storage ring. It is capable of measuring the position of a single bunch on the first or nth orbit to an accuracy of a few percent. Stored beam position is more accurately measured with averaging techniques. Beam position changes can be studied in a bandwidth from DC to a few MHz. The beam monitor electronics consist of a separate amplification, detection, and sampling channel for each beam pickup electrode. Fast switches in each channel permit selection of the nth turn for measurement (single bunch mode). A calibration pulse is injected into each channel after beam measurement to permit gain offsets to be measured and removed from the final data. While initially more costly than the usual beam position monitor system, this sytem will pay for itself in reduced storage ring debug and trouble shooting time. 5 refs., 5 figs

  18. Pulsed rf systems for large storage rings

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1979-03-01

    The possibility is considered that by using a pulsed rf system a substantial reduction can be made in the rf power requirement for the next generation of large storage rings. For a ring with a sufficiently large circumference, the time between bunch passages, T/sub b/, can exceed the cavity filling time, T/sub f/. As the ratio T/sub b//T/sub f/ increases, it is clear that at some point the average power requirement can be reduced by pulsing the rf to the cavities. In this mode of operation, the rf power is turned on a filling time or so before the arrival of a bunch and is switched off again at the time of bunch passage. There is no rf energy in the accelerating structure, and hence no power dissipation, for most of the period between bunches

  19. Asymmetric Catalytic Aza-Diels-Alder/Ring-Closing Cascade Reaction Forming Bicyclic Azaheterocycles by Trienamine Catalysis.

    Science.gov (United States)

    Li, Yang; Barløse, Casper; Jørgensen, Julie; Carlsen, Bjørn Dreiø; Jørgensen, Karl Anker

    2017-01-01

    An asymmetric catalytic aza-Diels-Alder/ring-closing cascade reaction between acylhydrazones and in situ formed trienamines is presented. The reaction proceeds through a formal aza-Diels-Alder cycloaddition, followed by a ring-closing reaction forming the hemiaminal ring leading to chiral bicyclic azaheterocycles in moderate to good yield (up to 71 %), good enantio- (up to 92 % ee) and diastereoselectivity (up to >20:1 d.r.). Furthermore, transformations are presented to show the potential application of the formed product. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The interaction of linear and ring forms of DNA molecules with nanodiamonds synthesized by detonation

    International Nuclear Information System (INIS)

    Purtov, K V; Burakova, L P; Puzyr, A P; Bondar, V S

    2008-01-01

    Nanodiamonds synthesized by detonation have been found not to immobilize the ring form of pUC19 plasmid DNA. Linear pUC19 molecules with blunt ends, prepared by restriction of the initial ring form of pUC19 DNA, and linear 0.25-10 kb DNA fragments are adsorbed on nanodiamonds. The amount of adsorbed linear DNA molecules depends on the size of the molecules and the size of the nanodiamond clusters

  1. Vortex rings in classical and quantum systems

    International Nuclear Information System (INIS)

    Barenghi, C F; Donnelly, R J

    2009-01-01

    The study of vortex rings has been pursued for decades and is a particularly difficult subject. However, the discovery of quantized vortex rings in superfluid helium has greatly increased interest in vortex rings with very thin cores. While rapid progress has been made in the simulation of quantized vortex rings, there has not been comparable progress in laboratory studies of vortex rings in a viscous fluid such as water. This article overviews the history and current frontiers of classical and quantum vortex rings. After introducing the classical results, this review discusses thin-cored vortex rings in superfluid helium in section 2, and recent progress in understanding vortex rings of very thin cores propagating in water in section 3. (invited paper)

  2. The kicker magnet system for TRISTAN Accumulation Ring injection

    International Nuclear Information System (INIS)

    Sakamoto, Y.; Satoh, K.; Nakayama, H.

    1994-12-01

    The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kicker power supply the charging to the main capacitor was done with the resonant charge system together with the auxiliary charging unit. The impedance matching circuit was added to the kicker magnet for getting the required current form with least reflecting oscillation. In this paper we report the performance of this kicker system. (author)

  3. Development of an Acoustic Levitation Linear Transportation System Based on a Ring-Type Structure.

    Science.gov (United States)

    Thomas, Gilles P L; Andrade, Marco A B; Adamowski, Julio Cezar; Silva, Emilio Carlos Nelli

    2017-05-01

    A linear acoustic levitation transportation system based on a ring-type vibrator is presented. The system is composed by two 21-kHz Langevin transducers connected to a ring-shaped structure formed by two semicircular sections and two flat plates. In this system, a flexural standing wave is generated along the ring structure, producing an acoustic standing wave between the vibrating ring and a plane reflector located at a distance of approximately a half wavelength from the ring. The acoustic standing wave in air has a series of pressure nodes, where small particles can be levitated and transported. The ring-type transportation system was designed and analyzed by using the finite element method. Additionally, a prototype was built and the acoustic levitation and transport of a small polystyrene particle was demonstrated.

  4. Tinea capitis in the form of concentric rings in an HIV positive adult on antiretroviral treatment

    Directory of Open Access Journals (Sweden)

    Kirti Narang

    2012-01-01

    Full Text Available Dermatophyte infection may present in the form of concentric rings caused by Trichophyton concentricum, known as Tinea Imbricata. In immunosuppressed patients, there are reports of lesions in the form of concentric rings caused by dermatophytes other than Trichophyton concentricum too, mostly by Trichophyton tonsurans, known as Tinea indesiciva or Tinea pseudoimbricata. We report a case of tinea capitis in a HIV-positive adult woman on antiretroviral therapy, who presented with concentric rings of papules and pustules with slight scaling on the scalp along with diffuse thinning of hair. Both Potassium hydroxide mount and culture showed the presence of Dermatophytes. Tinea capitis is considered rare in adults, but new cases are being reported in immunocompromised as well as in immunocompetent patients. The pertinent features of this case are: HIV-positive adult female on antiretroviral therapy, presenting with tinea capitis in the form of concentric rings; culture from the lesion grew Microsporum audouinii; responding to oral Terbinafine.

  5. A ring transducer system for medical ultrasound research.

    Science.gov (United States)

    Waag, Robert C; Fedewa, Russell J

    2006-10-01

    An ultrasonic ring transducer system has been developed for experimental studies of scattering and imaging. The transducer consists of 2048 rectangular elements with a 2.5-MHz center frequency, a 67% -6 dB bandwidth, and a 0.23-mm pitch arranged in a 150-mm-diameter ring with a 25-mm elevation. At the center frequency, the element size is 0.30lambda x 42lambda and the pitch is 0.38lambda. The system has 128 parallel transmit channels, 16 parallel receive channels, a 2048:128 transmit multiplexer, a 2048:16 receive multiplexer, independently programmable transmit waveforms with 8-bit resolution, and receive amplifiers with time variable gain independently programmable over a 40-dB range. Receive signals are sampled at 20 MHz with 12-bit resolution. Arbitrary transmit and receive apertures can be synthesized. Calibration software minimizes system nonidealities caused by noncircularity of the ring and element-to-element response differences. Application software enables the system to be used by specification of high-level parameters in control files from which low-level hardware-dependent parameters are derived by specialized code. Use of the system is illustrated by producing focused and steered beams, synthesizing a spatially limited plane wave, measuring angular scattering, and forming b-scan images.

  6. Convergent synthesis of the HIJKLM ring system of ciguatoxin CTX3C.

    Science.gov (United States)

    Takamura, Hiroyoshi; Nishiuma, Naoki; Abe, Takashi; Kadota, Isao

    2011-09-02

    The HIJKLM ring system of ciguatoxin CTX3C was synthesized in a convergent manner. The key steps were a conjugate addition/alkylation sequence, spiroacetalization, intramolecular allylation, ring-closing metathesis, and hydrogenation to form the 36-α-methyl substituent.

  7. Dynamical Evolution of Ring-Satellite Systems

    Science.gov (United States)

    Ohtsuki, Keiji

    2005-01-01

    The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

  8. Mid-Infrared Observations of Possible Intergalactic Star Forming Regions in the Leo Ring

    Science.gov (United States)

    Giroux, Mark; Smith, B.; Struck, C.

    2011-05-01

    Within the Leo group of galaxies lies a gigantic loop of intergalactic gas known as the Leo Ring. Not clearly associated with any particular galaxy, its origin remains uncertain. It may be a primordial intergalactic cloud alternatively, it may be a collision ring, or have a tidal origin. Combining archival Spitzer images of this structure with published UV and optical data, we investigate the mid-infrared properties of possible knots of star formation in the ring. These sources are very faint in the mid-infrared compared to star forming regions in the tidal features of interacting galaxies. This suggests they are either deficient in dust, or they may not be associated with the ring.

  9. Cavity Ring-down Spectroscopic System And Method

    KAUST Repository

    Alquaity, Awad Bin Saud

    2015-05-14

    A system and method for cavity ring-down spectroscopy can include a pulsed quantum cascade laser, an optical ring-down cavity, a photodetector, and an oscilloscope. The system and method can produce pulse widths of less than 200 ns with bandwidths greater than 300 pm, as well as provide temporal resolution of greater than 10 .mu.s.

  10. Cavity Ring-down Spectroscopic System And Method

    KAUST Repository

    Alquaity, Awad Bin Saud; Farooq, Aamir

    2015-01-01

    A system and method for cavity ring-down spectroscopy can include a pulsed quantum cascade laser, an optical ring-down cavity, a photodetector, and an oscilloscope. The system and method can produce pulse widths of less than 200 ns with bandwidths greater than 300 pm, as well as provide temporal resolution of greater than 10 .mu.s.

  11. Construction of vacuum system for Tristan accumulation ring

    International Nuclear Information System (INIS)

    Ishimaru, H.; Horikoshi, G.; Kobayashi, M.; Kubo, T.; Mizuno, H.; Momose, T.; Narushima, K.; Watanabe, H.; Yamaguchi, H.

    1983-01-01

    An all aluminum-alloy vacuum system for the TRISTAN accumulation ring is now under construction. Aluminum and aluminum alloys are preferred materials for ultrahigh vacuum systems of large electron storage rings because of their good thermal conductivity, extremely low outgassing rate, and low residual radioactivity. Vacuum beam chambers for the dipole and quadrupole magnets are extruded using porthole dies. The aluminum alloy 6063-T6 provides superior performance in extrusion. For ultrahigh vacuum performance, a special extrusion technique is applied which, along with the outgassing procedure used, is described in detail. Aluminum alloy 3004 seamless elliptical bellows are inserted between the dipole and quadrupole magnet chambers. These bellows are produced by the hydraulic forming of a seamless tube. The seamless bellows and the beam chambers are joined by fully automatic welding. The ceramic chambers for the kicker magnets, the fast bump magnets, and the slow beam intensity monitor are inserted in the aluminum alloy beam chambers. The ceramic chamber (98% alumina) and elliptical bellows are brazed with brazing sheets (4003-3003-4003) in a vacuum furnace. The brazing technique is described. The inner surface of the ceramic chamber is coated with a TiMo alloy by vacuum evaporation to permit a smooth flow of the RF wall current. Other suitable aluminum alloy components, including fittings, feedthroughs, gauges, optical windows, sputter ion pumps, turbomolecular pumps, and valves have been developed; their fabrication is described

  12. Virtual Exploration of the Ring Systems Chemical Universe.

    Science.gov (United States)

    Visini, Ricardo; Arús-Pous, Josep; Awale, Mahendra; Reymond, Jean-Louis

    2017-11-27

    Here, we explore the chemical space of all virtually possible organic molecules focusing on ring systems, which represent the cyclic cores of organic molecules obtained by removing all acyclic bonds and converting all remaining atoms to carbon. This approach circumvents the combinatorial explosion encountered when enumerating the molecules themselves. We report the chemical universe database GDB4c containing 916 130 ring systems up to four saturated or aromatic rings and maximum ring size of 14 atoms and GDB4c3D containing the corresponding 6 555 929 stereoisomers. Almost all (98.6%) of these ring systems are unknown and represent chiral 3D-shaped macrocycles containing small rings and quaternary centers reminiscent of polycyclic natural products. We envision that GDB4c can serve to select new ring systems from which to design analogs of such natural products. The database is available for download at www.gdb.unibe.ch together with interactive visualization and search tools as a resource for molecular design.

  13. Ring retroreflector system consisting of cube-corner reflectors with special coating

    International Nuclear Information System (INIS)

    Burmistrov, V B; Sadovnikov, M A; Sokolov, A L; Shargorodskiy, V D

    2013-01-01

    The ring retroreflector system (RS) consisting of cubecorner reflectors (CCRs) with a special coating of reflecting surfaces, intended for uniaxially Earth-oriented navigation satellites, is considered. The error of distance measurement caused by both the laser pulse delay in the CCR and its spatial position (CCR configuration) is studied. It is shown that the ring RS, formed by the CCR with a double-spot radiation pattern, allows the distance measurement error to be essentially reduced. (nanogradient dielectric coatings and metamaterials)

  14. Concise copper-catalyzed synthesis of tricyclic biaryl ether-linked aza-heterocyclic ring systems.

    Science.gov (United States)

    Mestichelli, Paola; Scott, Matthew J; Galloway, Warren R J D; Selwyn, Jamie; Parker, Jeremy S; Spring, David R

    2013-11-01

    A new method for the synthesis of tricyclic biaryl ether-linked ring systems incorporating seven-, eight-, and nine-membered ring amines is presented. In the presence of catalytic quantities of copper(I), readily accessible acyclic precursors undergo an intramolecular carbon-oxygen bond-forming reaction facilitated by a "templating" chelating nitrogen atom. The methodology displays a broad substrate scope, is practical, and generates rare and biologically interesting tricyclic heteroaromatic products that are difficult to access by other means.

  15. The Age of Saturn's Rings Constrained by the Meteoroid Flux Into the System

    Science.gov (United States)

    Kempf, S.; Altobelli, N.; Srama, R.; Cuzzi, J. N.; Estrada, P. R.

    2017-12-01

    The origin of Saturn's ring is still not known. There is an ongoing argument whether Saturn's ring are rather young or have been formed shortly after Saturn together with its satellites. The water-ice rings contain about 5% rocky material resulting from continuous meteoroid bombardment of the ring material with interplanetary micrometeoroids. Knowledge of the incoming mass flux would allow to estimate the ring's exposure time. Model calculations suggest exposure times of 108 years implying a late ring formation. This scenario is problematic because the tidal disruption of a Mimas-sized moon or of a comet within the planet's Roche zone would lead to a much larger rock content as observed today. Here we report on the measurement of the meteoroid mass flux into the Saturnian system obtained by the charge-sensitive entrance grid system (QP) of the Cosmic Dust Analyser (CDA) on the Cassini spacecraft. Interplanetary dust particles (IDPs) entering Saturn's sphere of gravitational influence are identified through the measurements of their speed vectors. We analyzed the full CDA data set acquired after Cassini's arrival at Saturn in 2004, identified the impact speed vectors of 128 extrinsic micrometeoroids ≥ 2 μm, and determined their orbital elements. On the basis of these measurements we determined the mass flux into the Saturnian system. Our preliminary findings are in support of an old ring. The knowledge of the meteoroids orbital elements allows us for the first time to characterize the meteoroid environment in the outer solar system based on direct measurements.

  16. Voyager Saturnian ring measurements and the early history of the solar system

    International Nuclear Information System (INIS)

    Alfven, H.; Axnaes, I.; Brenning, N.; Lindqvist, P.A.

    1986-01-01

    The mass distribution in the Saturnian ring system is investigated and compared with predictions from the plasma cosmogony. According to this theory, the matter in the rings has once been in the form of a magnetized plasma, in which the gravitation is balanced partly by the centrifugal force and partly by the electromagnetic forces. As the plasma is neutralized, the electromagnetic forces disappear and the matter can be shown to fall in to 2/3 of the original saturnocentric distance. This causes the so called ''cosmogonic shadow effect'', which has been demonstrated earlier for the asteroidal belt and in the large scale structure of the Saturnian ring system. The relevance of the cosmogonic shadow effect is investigated for parts of the Saturnian ring system. It is shown that many structures of the present ring system can be understood as shadows and antishadows of cosmogonic origin. These appear in the form of double rings centered around a position a factor 0.64(slightly less than 2/3) closer to Saturn than the causing feature. Voyager data agree with an accuracy better than 1%. (author)

  17. Preparation of nucleoside-pyridine hybrids and pyridine attached acylureas from an unexpected uracil ring-opening and pyridine ring-forming sequence

    Institute of Scientific and Technical Information of China (English)

    Xue Sen Fan; Xia Wang; Xin Ying Zhang; Dong Feng; Ying Ying Qu

    2009-01-01

    Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids (4) or pyridine attached acylureas (5) were selectively and efficiently prepared from the reaction of 2'-deoxyuridin-5-yl-methylene malonortitrile (1), malononitrile (2) and thiophenol (3) or from an unexpected uracil ring-opening and pyridine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.

  18. A ring system detected around the Centaur (10199) Chariklo.

    Science.gov (United States)

    Braga-Ribas, F; Sicardy, B; Ortiz, J L; Snodgrass, C; Roques, F; Vieira-Martins, R; Camargo, J I B; Assafin, M; Duffard, R; Jehin, E; Pollock, J; Leiva, R; Emilio, M; Machado, D I; Colazo, C; Lellouch, E; Skottfelt, J; Gillon, M; Ligier, N; Maquet, L; Benedetti-Rossi, G; Ramos Gomes, A; Kervella, P; Monteiro, H; Sfair, R; El Moutamid, M; Tancredi, G; Spagnotto, J; Maury, A; Morales, N; Gil-Hutton, R; Roland, S; Ceretta, A; Gu, S-h; Wang, X-b; Harpsøe, K; Rabus, M; Manfroid, J; Opitom, C; Vanzi, L; Mehret, L; Lorenzini, L; Schneiter, E M; Melia, R; Lecacheux, J; Colas, F; Vachier, F; Widemann, T; Almenares, L; Sandness, R G; Char, F; Perez, V; Lemos, P; Martinez, N; Jørgensen, U G; Dominik, M; Roig, F; Reichart, D E; LaCluyze, A P; Haislip, J B; Ivarsen, K M; Moore, J P; Frank, N R; Lambas, D G

    2014-04-03

    Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ±  9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.

  19. Quantized levitation states of superconducting multiple-ring systems

    International Nuclear Information System (INIS)

    Haley, S.B.; Fink, H.J.

    1996-01-01

    The quantized levitation, trapped, and suspension states of a magnetic microsphere held in equilibrium by two fixed superconducting (SC) microrings are calculated by minimizing the free energy of the system. Each state is a discrete function of two independent fluxoid quantum numbers of the rings. When the radii of the SC rings are of the same order as the Ginzburg-Landau coherence length ξ(T), the system exhibits a small set of gravity and temperature-dependent levels. The levels of a weakly magnetized particle are sensitive functions of the gravitational field, indicating potential application as an accelerometer, and for trapping small magnetic particles in outer space or on Earth. The equilibrium states of a SC ring levitated by another SC ring are also calculated. copyright 1996 The American Physical Society

  20. A progress report on the g-2 storage ring magnet system

    International Nuclear Information System (INIS)

    Bunce, G.; Cullen, J.; Danby, G.

    1995-01-01

    The 3.1 GeV muon storage ring for the g-2 experiment at Brookhaven National Laboratory hat three large solenoid magnets that form a continuous 1.451 tesla storage ring dipole with an average beam bond radius of 7.1 metors. In addition to the three storage ring solenoids, there is an inflector dipole with nested dipole coils that create very little stray magnetic field. A superconducting shield on the infractor gets rid of most of the remaining stray flux. This paper reports on the progress made on the storage ring solenoid magnet system and the inflector as of June 1995. The results of cryogenic system tests are briefly reported

  1. Normal form analysis of linear beam dynamics in a coupled storage ring

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Woodley, Mark D.

    2004-01-01

    The techniques of normal form analysis, well known in the literature, can be used to provide a straightforward characterization of linear betatron dynamics in a coupled lattice. Here, we consider both the beam distribution and the betatron oscillations in a storage ring. We find that the beta functions for uncoupled motion generalize in a simple way to the coupled case. Defined in the way that we propose, the beta functions remain well behaved (positive and finite) under all circumstances, and have essentially the same physical significance for the beam size and betatron oscillation amplitude as in the uncoupled case. Application of this analysis to the online modeling of the PEP-II rings is also discussed

  2. The Omega Ring Imaging Cerenkov Detector readout system user's guide

    International Nuclear Information System (INIS)

    Hallewell, G.

    1984-11-01

    The manual describes the electronic readout system of the Ring Imaging Cerenkov Detector at the CERN Omega Spectrometer. The system is described in its configuration of September 1984 after the Rich readout system had been used in two Omega experiments. (U.K.)

  3. Ring interconnection for distributed memory automation and computing system

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, V I [Inst. for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation)

    1996-12-31

    Problems of development of measurement, acquisition and central systems based on a distributed memory and a ring interface are discussed. It has been found that the RAM LINK-type protocol can be used for ringlet links in non-symmetrical distributed memory architecture multiprocessor system interaction. 5 refs.

  4. Proton storage ring (PSR) diagnostics and control system

    International Nuclear Information System (INIS)

    Clout, P.

    1983-01-01

    When any new accelerator or storage ring is built that advances the state of the art, the diagnostic system becomes extremely important in tuning the facility to full specification. This paper will discuss the various diagnostic devices planned or under construction for the PSR and their connection into the control system

  5. Model calibration and beam control systems for storage rings

    International Nuclear Information System (INIS)

    Corbett, W.J.; Lee, M.J.; Ziemann, V.

    1993-04-01

    Electron beam storage rings and linear accelerators are rapidly gaining worldwide popularity as scientific devices for the production of high-brightness synchrotron radiation. Today, everybody agrees that there is a premium on calibrating the storage ring model and determining errors in the machine as soon as possible after the beam is injected. In addition, the accurate optics model enables machine operators to predictably adjust key performance parameters, and allows reliable identification of new errors that occur during operation of the machine. Since the need for model calibration and beam control systems is common to all storage rings, software packages should be made that are portable between different machines. In this paper, we report on work directed toward achieving in-situ calibration of the optics model, detection of alignment errors, and orbit control techniques, with an emphasis on developing a portable system incorporating these tools

  6. Substrate system for spray forming

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

    2002-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  7. Study of RF system of Hefei storage ring under injection

    International Nuclear Information System (INIS)

    Xu Hongliang; Wang Lin; Li Yongjun; Huang Guirong; Zhang Pengfei; Li Weimin; Liu Zuping; He Duohui

    2004-01-01

    In this paper, the beam loading effect of RF system and the conditions of Robinson instability are analyzed in detail. By the study of the injection beam intensity limit dependent on detune angle and visible detune angle, it is found that the storage ring can be injected to more than 300 mA current intensity to attain the design target of phase II project in the lower energy injection situation of Hefei Storage Ring if a certain power is feed in the RF cavity and a certain tuning angle of the RF cavity is set

  8. The beam loss monitoring system for HLS storage ring

    CERN Document Server

    Li Yu Xiong; Li Wei; Li Jue Xin; Liu Zu Ping; Shao Bei Bei

    2001-01-01

    A beam loss monitoring system has been established at HLS. This paper gives its principle and scientific grounds. Study on the ring's TBA structure and utilization of Monte-Carlo calculation to the shower electrons is important in its design. The system composition and performance are also introduced. The detector BLMs, data acquisition devices and host PC are linked via CAN bus. This system is helpful to analyze beam loss distribution and regulate the machine operation parameters.

  9. A primary microcephaly protein complex forms a ring around parental centrioles.

    Science.gov (United States)

    Sir, Joo-Hee; Barr, Alexis R; Nicholas, Adeline K; Carvalho, Ofelia P; Khurshid, Maryam; Sossick, Alex; Reichelt, Stefanie; D'Santos, Clive; Woods, C Geoffrey; Gergely, Fanni

    2011-10-09

    Autosomal recessive primary microcephaly (MCPH) is characterized by a substantial reduction in prenatal human brain growth without alteration of the cerebral architecture and is caused by biallelic mutations in genes coding for a subset of centrosomal proteins. Although at least three of these proteins have been implicated in centrosome duplication, the nature of the centrosome dysfunction that underlies the neurodevelopmental defect in MCPH is unclear. Here we report a homozygous MCPH-causing mutation in human CEP63. CEP63 forms a complex with another MCPH protein, CEP152, a conserved centrosome duplication factor. Together, these two proteins are essential for maintaining normal centrosome numbers in cells. Using super-resolution microscopy, we found that CEP63 and CEP152 co-localize in a discrete ring around the proximal end of the parental centriole, a pattern specifically disrupted in CEP63-deficient cells derived from patients with MCPH. This work suggests that the CEP152-CEP63 ring-like structure ensures normal neurodevelopment and that its impairment particularly affects human cerebral cortex growth.

  10. The vacuum interlock system for the CELSIUS ring

    International Nuclear Information System (INIS)

    Gajewski, K.

    1990-01-01

    A vacuum interlock system has been designed and built for the CELSIUS storage ring. The ultrahigh-vacuum system of CELSIUS has a design pressure of 10 -11 mbar. This is achieved by using vacuum-fired stainless-steel chambers, baking the whole ring to 300degC and running some 50 sputter ion and titanium sublimation pumps. The turbopumps, combined with roughing pumps, are used during the pump-down and the bake-out. The pressure is monitored by Penning vacuum gauges. There is a number of programmable pressure thresholds set to trigger various events (like closing the sector valves, disabling the bake-out, etc.). The interlock system is based on the Mitsubishi programmable logic controller (PLC). An IBM PC is used as an operator's console. The operation and performance of the system is described. On the basis of present experience an upgrading of the system is suggested. (orig.)

  11. Position Ring System using Anger Type Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Joel S. Karp, principal investigator

    2004-12-14

    The overall objective of our project was to develop PET scanners and imaging techniques that achieve high performance and excellent image quality. Our approach was based upon 3-D imaging (no septa) with position-sensitive Anger-logic detectors, whereby the encoding ratio of resolution elements to number of photo-multiplier tube channels is very high. This design led to a series of PET systems that emphasized cost-effectiveness and practicality in a clinical environment.

  12. The injection system of the stretcher ring ELSA

    International Nuclear Information System (INIS)

    Dreist, A.

    1989-07-01

    For the stretcher ring ELSA in the framwork of this thesis an injection system has been concipated and constructed which should allow all projected operational modes of this stretcher ring, the stretcher, the post-acceleration, and the accumulation mode. The proof could be performed that the realized concept allows all these operational modes. Furthermore it could be shown that the injection shifted from the equilibrium orbit has no disadvantageous effects on a uniform extraction and by this on a high touching ratio. In fact it is even possible to apply the decay of the coherent betatron oscillations around the equilibrium orbit, caused by injection of the incident beam shifted from the equilibrium orbit, to diagnosis purposes: By reproduction of this damping process in a simulation model statements on nonlinearities present in the ring and by this statements on the actual phase-space structure are possible. It has so been shown that the concept presented in this thesis and realized for this thesis represents a suited injection system for the stretcher ring ELSA. (orig.) [de

  13. The fluid systems for the SLD Cherenkov ring imaging detector

    International Nuclear Information System (INIS)

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Schneider, M.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.

    1992-10-01

    We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C 2 H 6 + TMAE), radiator gas (C 5 F 12 + N 2 ) and radiator liquid (C 6 F 14 ). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported

  14. The Role of Ionospheric O+ in Forming the Storm-time Ring Current

    Science.gov (United States)

    Kistler, L. M.; Mouikis, C.; Menz, A.; Bingham, S.

    2017-12-01

    During storm times, the particle pressure that creates the storm-time ring current in the inner magnetosphere can be dominated by O+. This is surprising, as the immediate source for the ring current is the nightside plasma sheet, and O+ is usually not the dominant species in the plasma sheet. In this talk we examine the many factors that lead to this result. The O+ outflow is enhanced during geomagnetically active times. The transport paths of O+ and H+ are different, such that the O+ that reaches the near-earth plasma sheet is more energetic than H+. The source spectrum in the near-earth plasma sheet can be harder for O+ than for H+, perhaps due to substorm injections, so that the more energetic plasma has a higher O+/H+ ratio. And finally the plasma sheet O+ can be more abundant towards the beginning of the storm, when the convection is largest, so the enhanced O+ is brought the deepest into the inner magnetosphere. We will discuss the interrelationships between these different effects as well as the ways in which O+ itself may influence the system.

  15. Survey of Digital Feedback Systems in High Current Storage Rings

    International Nuclear Information System (INIS)

    Teytelman, Dmitry

    2003-01-01

    In the last decade demand for brightness in synchrotron light sources and luminosity in circular colliders led to construction of multiple high current storage rings. Many of these new machines require feedback systems to achieve design stored beam currents. In the same time frame the rapid advances in the technology of digital signal processing allowed the implementation of these complex feedback systems. In this paper I concentrate on three applications of feedback to storage rings: orbit control in light sources, coupled-bunch instability control, and low-level RF control. Each of these applications is challenging in areas of processing bandwidth, algorithm complexity, and control of time-varying beam and system dynamics. I will review existing implementations as well as comment on promising future directions

  16. The structure and stability of orbits in Hoag-like ring systems

    Science.gov (United States)

    Bannikova, Elena Yu

    2018-05-01

    Ring galaxies are amazing objects exemplified by the famous case of Hoag's Object. Here the mass of the central galaxy may be comparable to the mass of the ring, making it a difficult case to model mechanically. In a previous paper, it was shown that the outer potential of a torus (ring) can be represented with good accuracy by the potential of a massive circle with the same mass. This approach allows us to simplify the problem of the particle motion in the gravitational field of a torus associated with a central mass by replacing the torus with a massive circle. In such a system, there is a circle of unstable equilibrium that we call `Lagrangian circle' (LC). Stable circular orbits exist only in some region limited by the last possible circular orbit related to the disappearance of the extrema of the effective potential. We call this orbit `the outermost stable circular orbit' (OSCO) by analogy with the innermost stable circular orbit (ISCO) in the relativistic case of a black hole. Under these conditions, there is a region between OSCO and LC where the circular motion is not possible due to the competition between the gravitational forces by the central mass and the ring. As a result, a gap in the matter distribution can form in Hoag-like system with massive rings.

  17. Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system.

    Science.gov (United States)

    Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

    2016-12-12

    The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices.

  18. Beam vacuum system of Brookhaven's muon storage ring

    International Nuclear Information System (INIS)

    Hseuth, H.C.; Snydstrup, L.; Mapes, M.

    1995-01-01

    A storage ring with a circumference of 45 m is being built at Brookhaven to measure the g-2 value of the muons to an accuracy of 0.35 ppm.. The beam vacuum system of the storage ring will operate at 10 -7 Torr and has to be completely non-magnetic. It consists of twelve sector chambers. The chambers are constructed of aluminum and are approximately 3.5 m in length with a rectangular cross-section of 16.5 cm high by 45 cm at the widest point. The design features, fabrication techniques and cleaning methods for these chambers are described. The beam vacuum system will be pumped by forty eight non-magnetic distributed ion pumps with a total pumping speed of over 2000 ell/sec. Monte Carlo simulations of the pressure distribution in the muon storage region are presented

  19. The g-2 storage ring superconducting magnet system

    International Nuclear Information System (INIS)

    Green, M.A.

    1993-09-01

    The g-2 μ lepton (muon) storage ring is a single dipole magnet that is 44 meters in circumference. The storage ring dipole field is created by three large superconducting solenoid coils. A single outer solenoid, 15.1 meters in diameter, carries 254 kA. Two inner solenoids, 13.4 meters in diameter, carry 127 kA each in opposition to the current carried by the outer solenoid. A room temperature C shaped iron yoke returns the magnetic flux and shapes the magnetic field in a 180 mm gap where the stored muon beam circulates. The gap induction will be 1.47 T. This report describes the three large superconducting solenoids, the cryogenic system needed to keep them cold, the solenoid power supply and the magnet quench protection system

  20. Forming mechanism and avoiding measures of blue-ring on electronic beam welding sample after water corrosion

    International Nuclear Information System (INIS)

    Ren Defang; Luo Xiandian; Tong Shenxiu; Guo Xulin; Peng Haiqing

    2001-01-01

    After water corrosion in compliance with ASTM G2, the blue ring appears on the nuclear fuel rod samples of AFA 2G welded by using a Big Chamber Electron Beam Welder made in Russia. The characteristics, appearance, chemical composition, microstructure of b lue ring a nd some condition test are described. The mechanism of forming blue ring may be depicted as following: welding metal vapor and the splash produced by secondary and scatter electrons on metal clamp and gun body deposit in the area between HAZ and substrate because of the water cooling down effects on the clamp; these deposits, after water corrosion, appears as blue ring on the fuel rod surface. Avoiding measure is that the side of the clamp closing to weld seal is chamfered, while making the welding chamber cleaner

  1. Circadian clock protein KaiC forms ATP-dependent hexameric rings and binds DNA.

    Science.gov (United States)

    Mori, Tetsuya; Saveliev, Sergei V; Xu, Yao; Stafford, Walter F; Cox, Michael M; Inman, Ross B; Johnson, Carl H

    2002-12-24

    KaiC from Synechococcus elongatus PCC 7942 (KaiC) is an essential circadian clock protein in cyanobacteria. Previous sequence analyses suggested its inclusion in the RecADnaB superfamily. A characteristic of the proteins of this superfamily is that they form homohexameric complexes that bind DNA. We show here that KaiC also forms ring complexes with a central pore that can be visualized by electron microscopy. A combination of analytical ultracentrifugation and chromatographic analyses demonstrates that these complexes are hexameric. The association of KaiC molecules into hexamers depends on the presence of ATP. The KaiC sequence does not include the obvious DNA-binding motifs found in RecA or DnaB. Nevertheless, KaiC binds forked DNA substrates. These data support the inclusion of KaiC into the RecADnaB superfamily and have important implications for enzymatic activity of KaiC in the circadian clock mechanism that regulates global changes in gene expression patterns.

  2. Synthesis of a new class of fused cyclotetraphosphazene ring systems.

    Science.gov (United States)

    Beşli, Serap; Mutlu, Ceylan; İbişoğlu, Hanife; Yuksel, Fatma; Allen, Christopher W

    2015-01-05

    Octachlorocyclotetraphosphazene (1) was reacted with butylamines [n-butyl, i-butyl, sec-butyl, and t-butyl] in a 1:0.8 mol ratio in THF to obtain cyclotetraphosphazenes bearing a P-NH group, N4P4Cl7(NHR) [R = n-butyl (2a), i-butyl (2b), sec-butyl (2c), t-butyl (2d)](2a-d). The cyclotetraphosphazene derivatives 2a, 2b, and 2c were treated with sodium hydride giving rise to a new type of cyclophosphazene compounds (P8N8 ring) consisting of three fused tetramer rings (3a-c). Whereas reaction of sodium hydride with the t-butylaminocyclophosphazene derivative (2d) gave a P-O-P bridged compound (4) presumably as a result of hydrolysis reaction associated with moisture in the solvent. It is likely that the 16-membered cyclooctaphosphazene derivatives (3a-c) are formed by a proton abstraction/chloride ion elimination, intramolecular nucleophilic attack, ring opening and intermolecular condensation processes, respectively.

  3. Saturn Rings Origin: Quantum Trapping of Superconducting Iced Particles and Meissner Effect Lead to the Stable Rings System

    Science.gov (United States)

    Viktorovich Tchernyi, Vladimir

    2018-06-01

    Saturn Rings Origin: Quantum Trapping of Superconducting Iced Particles and Meissner Effect Lead to the Stable Rings System Vladimir V. Tchernyi (Cherny), Andrew Yu. Pospelov Modern Science Institute, SAIBR, Moscow, Russia. E-mail: chernyv@bk.ruAbstractIt is demonstrated how superconducting iced particles of the protoplanetary cloud of Saturn are coming to magnetic equator plane and create the stable enough rings disk. There are two steps. First, after appearance of the Saturn magnetic field due to Meissner phenomenon all particles orbits are moving to the magnetic equator plane. Finally they become distributed as rings and gaps like iron particles around magnet on laboratory table. And they are separated from each other by the magnetic field expelled from them. It takes up to few tens of thousands years with ten meters rings disk thickness. Second, due to their quantum trapping all particles become to be trapped within magnetic well at the magnetic equator plane due to Abrikosov vortex for superconductor. It works even when particles have small fraction of superconductor. During the rings evolution some contribution to the disk also could come from the collision-generated debris of the current moon and from the geysers like it happened due to magnetic coupling of Saturn and Enceladus. The rings are relict of the early days of the magnetic field of Saturn system.

  4. Los Alamos Proton Storage Ring (PSR) injection deflector system

    International Nuclear Information System (INIS)

    Jason, A.j.; Higgins, E.F.; Koelle, A.R.

    1983-01-01

    We describe a pulsed magnetic deflector system planned for the injection system of the PSR. Two sets of magnets, appropriately placed in the optical systems of both the ring and the injection transport line, provide control of the rate at which particles are injected into a given portion of transverse phase space and limit the interaction of stored beam with the injection stripping foil. High-current modulators that produce relatively complex waveforms are required for this purpose. Solid-state drivers using direct feedback to produce the necessary waveforms are discussed as replacements for the more conventional high-voltage tube technology

  5. Data exchange system in cooler-storage-ring virtual accelerator

    International Nuclear Information System (INIS)

    Liu Wufeng; Qiao Weimin; Jing Lan; Guo Yuhui

    2009-01-01

    The data exchange system of the cooler-storage-ring (CSR) control system for heavy ion radiotherapy has been introduced for the heavy ion CSR at Lanzhou (HIRFL-CSR). Using techniques of Java, component object model (COM), Oracle, DSP and FPGA, this system can achieve real-time control of magnet power supplies sanctimoniously, and control beams and their switching in 256 energy levels. It has been used in the commissioning of slow extraction for the main CSR (CSRm), showing stable and reliable performance. (authors)

  6. Vacuum system for the NIJI-III compact storage ring

    International Nuclear Information System (INIS)

    Miura, F.; Tsutsui, Y.; Takada, H.

    1990-01-01

    The NIJI-III is a compact storage ring measuring about 15 m in circumference with four superconducting bending magnets. It is under development as a synchrotron light source for X-ray lithography with a stored beam current of 200 mA at a stored beam current of 200 mA at a stored energy level of 615 MeV. The vacuum system is designed to attain a pressure of less than 1 x 10 -9 Torr at beam storage. The compact ring design makes it difficult to install a large number of pumps able to satisfy the required pumping speed. For the purpose of realizing a high pumping speed, a cryopump as a result of cooling the superconducting magnet duct wall to the liquid helium (LHe) temperature is adopted, as a result the total pumping speed to 2.8 x 10 4 l/s is obtained. (author)

  7. MATLAB based beam orbit correction system of HLS storage ring

    International Nuclear Information System (INIS)

    Ding Shichuan; Liu Gongfa; Xuan Ke; Li Weimin; Wang Lin; Wang Jigang; Li Chuan; Bao Xun; Guo Weiqun

    2006-01-01

    The distortion of closed orbit usually causes much side effect which is harmful to synchrotron radiation source such as HLS, so it is necessary to correct the distortion of closed orbit. In this paper, the correction principle, development procedure and test of MATLAB based on beam orbit correction system of HLS storage ring are described. The correction system is consisted of the beam orbit measure system, corrector magnet system and the control system, and the beam orbit correction code based on MATLAB is working on the operation interface. The data of the beam orbit are analyzed and calculated firstly, and then the orbit is corrected by changing corrector strength via control system. The test shows that the distortion of closed orbit is from max 4.468 mm before correction to max 0.299 mm after correction as well as SDEV is from 2.986 mm to 0.087 mm. So the correction system reaches the design goal. (authors)

  8. Cryogenic systems for large superconducting accelerators/storage rings

    International Nuclear Information System (INIS)

    Brown, D.P.

    1981-01-01

    Particle accelerators and storage rings which utilize superconducting magnets have presented cryogenic system designers, as well as magnet designers, with many new challenges. When such accelerators were first proposed, little operational experience existed to guide the design. Two superconducting accelerators, complete with cryogenic systems, have been designed and are now under construction. These are the Fermilab Doubler Project and the Brookhaven National Laboratory ISABELLE Project. The cryogenic systems which developed at these two laboratories share many common characteristics, especially as compared to earlier cryogenic systems. Because of this commonality, these characteristics can be reasonably taken as also being representative of future systems. There are other areas in which the two systems are dissimilar. In those areas, it is not possible to state which, if either, will be chosen by future designers. Some of the design parameters for the two systems are given

  9. Radio frequency system of the RIKEN ring cyclotron

    International Nuclear Information System (INIS)

    Fujisawa, T.; Ogiwara, K.; Kohara, S.; Oikawa, Y.; Yokoyama, I.; Nagase, M.; Takeshita, I.; Chiba, Y.; Kumata, Y.

    1987-01-01

    The radio-frequency(RF) system of the RIKEN ring cyclotron(K = 540) is required to work in a frequency range of 20 to 45 MHz and to generate the maximum acceleration voltage 250 kV. A new movable box type variable frequency resonator was designed for that purpose. The final amplifier is capable to deliver 300 kW. The resonators and the amplifiers have been installed at RIKEN and the performances are studied. The result shows the movable box type resonator and the power amplifier system satisfy the design aim. (author)

  10. Conceptual Design of ILC Damping Ring Wiggler Straight Vacuum System

    International Nuclear Information System (INIS)

    Marks, S.; Kennedy, K.; Plate, D.; Schlueter, R.D.; Zisman, M.

    2007-01-01

    The positron and electron damping rings for the International Linear Collider will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR superconducting design. There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC Reference Design Report. Particular emphasis will be placed on photon power load calculations and the absorber design

  11. Advances in metal forming expert system for metal forming

    CERN Document Server

    Hingole, Rahulkumar Shivajirao

    2015-01-01

    This comprehensive book offers a clear account of the theory and applications of advanced metal forming. It provides a detailed discussion of specific forming processes, such as deep drawing, rolling, bending extrusion and stamping. The author highlights recent developments of metal forming technologies and explains sound, new and powerful expert system techniques for solving advanced engineering problems in metal forming. In addition, the basics of expert systems, their importance and applications to metal forming processes, computer-aided analysis of metalworking processes, formability analysis, mathematical modeling and case studies of individual processes are presented.

  12. Beam monitors and transverse feedback system of TRISTAN Main Ring

    International Nuclear Information System (INIS)

    Ieiri, T.; Ishii, H.; Kishiro, J.; Mizumachi, Y.; Mori, K.; Nakajima, K.; Ogata, A.; Shintake, T.; Tejima, M.

    1987-01-01

    The construction of 30 GeV TRISTAN Main Ring (MR) started in 1983 soon after the commissioning of 8 GeV Accumulation Ring (AR). The authors prepared 392 position monitors, 6 synchrotron radiation monitors, 9 screen monitors, 2 DCCT's, 3 scrapers, 12 bunch monitors, transverse feedback systems for two beams and DC separators. Since the required monitoring devices of AR and MR are almost the same, the experiences in AR were very useful in the design of MR monitors. However, machine parameters of two rings are very different and the authors had to review the performance of each item. From the monitor point of view the most important is the difference of revolution frequency; 794.6 kHz for AR and 99.33 kHz for MR. This means that average beam current of MR is 1/8 as small as AR current with the same bunch number and intensity. Therefore, the sensitivity of each monitor must be better in MR. The second difference is that MR should be used as a collider from the beginning. Therefore they must prepare for multi-beam and multi-bunch operation

  13. TRANSIT MODEL OF PLANETS WITH MOON AND RING SYSTEMS

    International Nuclear Information System (INIS)

    Tusnski, Luis Ricardo M.; Valio, Adriana

    2011-01-01

    Since the discovery of the first exoplanets, those most adequate for life to begin and evolve have been sought. Due to observational bias, however, most of the discovered planets so far are gas giants, precluding their habitability. However, if these hot Jupiters are located in the habitable zones of their host stars, and if rocky moons orbit them, then these moons may be habitable. In this work, we present a model for planetary transit simulation considering the presence of moons and planetary rings around a planet. The moon's orbit is considered to be circular and coplanar with the planetary orbit. The other physical and orbital parameters of the star, planet, moon, and rings can be adjusted in each simulation. It is possible to simulate as many successive transits as desired. Since the presence of spots on the surface of the star may produce a signal similar to that of the presence of a moon, our model also allows for the inclusion of starspots. The result of the simulation is a light curve with a planetary transit. White noise may also be added to the light curves to produce curves similar to those obtained by the CoRoT and Kepler space telescopes. The goal is to determine the criteria for detectability of moons and/or ring systems using photometry. The results show that it is possible to detect moons with radii as little as 1.3 R ⊕ with CoRoT and 0.3 R ⊕ with Kepler.

  14. High resolution upgrade of the ATF damping ring BPM system

    International Nuclear Information System (INIS)

    Terunuma, N.; Urakawa, J.; Frisch, J.; May, J.; McCormick, D.; Nelson, J.; Seryi, A.; Smith, T.; Woodley, M.; Briegel, C.; Dysert, R.

    2008-01-01

    A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished in its first stage, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R and D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital downconversion techniques, digital signal processing, and also tests a new automatic gain error correction schema. The technical concept and realization, as well as preliminary results of beam studies are presented

  15. O-Ring sealing arrangements for ultra-high vacuum systems

    Science.gov (United States)

    Kim, Chang-Kyo; Flaherty, Robert

    1981-01-01

    An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

  16. Klystron 'efficiency loop' for the ALS storage ring RF system

    International Nuclear Information System (INIS)

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-01-01

    The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron

  17. THREE-DIMENSIONAL DUST MAPPING REVEALS THAT ORION FORMS PART OF A LARGE RING OF DUST

    International Nuclear Information System (INIS)

    Schlafly, E. F.; Rix, H.-W.; Martin, N. F.; Green, G.; Finkbeiner, D. P.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.; Draper, P. W.; Metcalfe, N.; Price, P. A.

    2015-01-01

    The Orion Molecular Complex is the nearest site of ongoing high-mass star formation, making it one of the most extensively studied molecular complexes in the Galaxy. We have developed a new technique for mapping the three-dimensional distribution of dust in the Galaxy using Pan-STARRS1 photometry. We isolate the dust at the distance to Orion using this technique, revealing a large (100 pc, 14° diameter), previously unrecognized ring of dust, which we term the ''Orion dust ring''. The ring includes Orion A and B, and is not coincident with current Hα features. The circular morphology suggests formation as an ancient bubble in the interstellar medium, though we have not been able to conclusively identify the source of the bubble. This hint at the history of Orion may have important consequences for models of high-mass star formation and triggered star formation

  18. Atmospheric pressure microwave plasma system with ring waveguide

    International Nuclear Information System (INIS)

    Liu Liang; Zhang Guixin; Zhu Zhijie; Luo Chengmu

    2007-01-01

    Some scientists used waveguide as the cavity to produce a plasma jet, while large volume microwave plasma was relatively hard to get in atmospheric pressure. However, a few research institutes have already developed devices to generate large volume of atmospheric pressure microwave plasma, such as CYRANNUS and SLAN series, which can be widely applied. In this paper, present a microwave plasma system with ring waveguide to excite large volume of atmospheric pressure microwave plasma, plot curves on theoretical disruption electric field of some working gases, emulate the cavity through software, measure the power density to validate and show the appearance of microwave plasma. At present, large volume of argon and helium plasma have already been generated steadily by atmospheric pressure microwave plasma system. This research can build a theoretical basis of microwave plasma excitation under atmospheric pressure and will be useful in study of the device. (authors)

  19. Photometric Analysis of the Jovian Ring System and Modeling of Ring Origin and Evolution

    Science.gov (United States)

    Esposito, L. W.

    2003-01-01

    We have successfully completed the work described in our proposal. The work supported by this grant resulted in the publication of the following paper: Brooks, S. M., L. W. Esposito, M. R. Showalter, and H. B. Throop. 2002. The size distribution of Jupiter's main ring from Galileo imaging and spectroscopy. Icarus, in press. This was also the major part of Dr. Shawn Brooks PhD dissertation. Dr. Brooks gave oral presentations on this work at the Lunar and Planetary Conference, the annual meetings of the Division for Planetary Sciences of the American Astronomical Society, the annual meetings of the European Geophysical Society, the international Jupiter Conference in Boulder, the Jupiter after Galileo and Cassini Conference in Lisbon and to the Working Group in Non-Linear Dynamics in Potsdam, Germany. This work was reviewed in: Esposito, L. W. 2002. Planetary rings. Rep. hog. Phys. 65, 1741-1783. Planetary rings. LASP reprint 874. Online at http://stacks.iop.org/RoPP/65/1741. Dr. Esposito gave presentations at schools and over the internet on the results of this work. Dr. Brooks lectured in undergraduate and graduate classes on Jupiter's rings, and on the meaning of his research. In August 2003, Dr. Shawn Brooks received the Phd degree from the University of Colorado in Astrophysical and Planetary Sciences.

  20. Commissioning results of the APS storage ring diagnostics systems

    International Nuclear Information System (INIS)

    Lumpkin, A.H.

    1996-01-01

    Initial commissionings of the Advanced Photon Source (APS) 7-GeV storage ring and its diagnostics systems have been done. Early studies involved single-bunch measurements for beam transverse size (σ x ∼ 150 μm, σ y ∼ 50 μm), current, injection losses, and bunch length. The diagnostics have been used in studies related to the detection of an extra contribution to beam jitter at ∼ 6.5 Hz frequency; observation of bunch lengthening (σ ∼ 30 to 60 ps) with single-bunch current; observation of an induced vertical, head-tail instability; and detection of a small orbit change with insertion device gap position. More recently, operations at 100-mA stored-beam current, the baseline design goal, have been achieved with the support of beam characterizations

  1. Commissioning of the diamond light source storage ring vacuum system

    International Nuclear Information System (INIS)

    Cox, M P; Boussier, B; Bryan, S; Macdonald, B F; Shiers, H S

    2008-01-01

    The Diamond storage ring has been operating with a 3 GeV electron beam since September 2006 and 190 A.h of beam dose have been accumulated. The pressure in the storage ring is 4.2 10 -10 mbar without beam, rising to 7.9 10 -10 mbar with 125 mA of stored beam. Data on the storage ring vacuum performance and experience from commissioning and beam conditioning are presented

  2. Quantum correlations in a bipartite multiqubit spin ring system

    International Nuclear Information System (INIS)

    Doronin, S I; Fel’dman, E B; Kuznetsova, E I

    2015-01-01

    We consider a spin ring with an arbitrary number of spins on the ring and one spin in its center in a strong external magnetic field. The spins on the ring are connected by the secular dipole–dipole interactions and interact with the central spin through the Heisenberg zz-interaction. We show that the quantum discord, describing quantum correlations between the ring and the central spin, can be obtained analytically for an arbitrary number of the spins in the high-temperature approximation. We demonstrate the evolution of quantum correlations at different numbers of the spins. The contributions of longitudinal and transversal spin interactions to the quantum discord are discussed. (paper)

  3. Structure and magnetic field of periodic permanent magnetic focusing system with open magnetic rings

    International Nuclear Information System (INIS)

    Peng Long; Li Lezhong; Yang Dingyu; Zhu Xinghua; Li Yuanxun

    2011-01-01

    The magnetic field along the central axis for an axially magnetized permanent magnetic ring was investigated by analytical and finite element methods. For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. A new structure of periodic permanent magnet focusing system with open magnetic rings is proposed. The structure provides a satisfactory magnetic field with a stable peak value of 120 mT for a traveling wave tube system. - Research highlights: → For open magnetic rings, both calculated and measured results show that the existence of the radial magnetic field creates a remarkable cosine distribution field along the central axis. → A new structure of periodic permanent magnet (PPM) focusing system with open magnetic rings is proposed. → The new PPM focusing system with open magnetic rings meets the requirements for TWT system.

  4. Entering the boxing ring: intergroup behavior in multiteam systems

    NARCIS (Netherlands)

    Wijnmaalen, Julia

    2015-01-01

    Organizations nowadays need to adjust quickly to new challenges. Consequently they are in need of a form of cooperation to help them react more efficiently. A Multiteam system (MTS) is such a form of cooperation. MTSs are two or more teams that interface directly and interdependently and that need

  5. Erosive forms in rivers systems

    International Nuclear Information System (INIS)

    Una Alvarez, E. de; Vidal Romani, J. R.; Rodriguez Martinez-Conde, R.

    2009-01-01

    The purpose of this work is to analyze the geomorphological meaning of the concepts of stability/change and to study its influence on a fluvial erosion system. Different cases of fluvial potholes in Galicia (NW of the Iberian Peninsula) are considered. The work conclusions refer to the nature of the process and its morphological evolution in order to advance towards later contributions with respect of this type of systems. (Author) 14 refs.

  6. The Beam Loss Detection System of the LHC Ring

    CERN Document Server

    Gschwendtner, E; Ferioli, G; Friesenbichler, W; Kain, V

    2002-01-01

    At the Large Hadron Collider (LHC) a beam loss system will be installed in the arc, dispersion suppressor and the straight regions for a continuous surveillance of particle losses. These beam particles deposit their energy partially in the super-conducting coils leading to temperature increase, possible magnet quenches and damages. The primary and secondary halo of the beam is absorbed by the collimation system. The tertiary halo will be lost at aperture limits in the ring. Its loss distribution along the magnets has been studies. At the positions, where most of the beam losses are expected, simulations of the particle fluences outside the cryostat and induced by lost protons at the aperture have been performed with the Monte Carlo Code Geant 3.2.1. This allows determining the most suitable positions of the detectors, the needed number of monitors and the impact on the dynamic range of the detectors. The design of the beam loss monitor system is presented that meet the required sensitivity, dynamic range and ...

  7. Electronic de-multipliers II (ring-shape systems)

    International Nuclear Information System (INIS)

    Raievski, V.

    1948-09-01

    This report describes a new type of ring-shape fast electronic counter (de-multiplier) with a resolution capacity equivalent to the one made by Regener (Rev. of Scientific Instruments USA 1946, 17, 180-89) but requiring two-times less electronic valves. This report follows the general description of electronic de-multipliers made by J. Ailloud (CEA--001). The ring comprises 5 flip-flop circuits with two valves each. The different elements of the ring are calculated with enough details to allow the transfer of this calculation to different valve types. (J.S.)

  8. The magic ring systems thinking approach to control systems

    CERN Document Server

    Mella, Piero

    2014-01-01

    This book presents a gradual path toward ""educating"" readers in understanding how Control Systems truly operate and in recognizing, simulating and improving them in all fields of activity. Starting from the hypothesis that knowledge of Control Systems is not only a technical fact but also represents a discipline - that is, ""A discipline is a developmental path for acquiring certain skills or competencies. (...) To practice a discipline is to be a lifelong learner. You ""never arrive""; you spend your life mastering disciplines."" (Senge, 2006, p. 10) - Piero Mella has set the objective of m

  9. A pilot investigation to constrain the presence of ring systems around transiting exoplanets

    Science.gov (United States)

    Hatchett, W. Timothy; Barnes, Jason W.; Ahlers, John P.; MacKenzie, Shannon M.; Hedman, Matthew M.

    2018-04-01

    We demonstrate a process by which to evaluate the presence of large, Saturn-like ring systems around transiting extrasolar giant planets. We use extrasolar planet candidate KOI-422.01 as an example around which to establish limits on the presence of ring systems. We find that the spherical-planet (no-rings) fit matches the lightcurve of KOI-422.01 better than a lightcurve with a planet having obliquity angles 90°, 60°, 45°, or 20°. Hence we find no evidence for rings around KOI-422.01, but the methods that we have developed can be used for more comprehensive ring searches in the future. If the Hedman (2015) low-temperature rings hypothesis is correct, then the first positive detection of exorings might require transits of very long period ( ≳ 10 yr) giant planets outside their stars' ice lines.

  10. Numerical simulation study on new RF system of Hefei storage ring

    International Nuclear Information System (INIS)

    Xu Hongliang; Wang Lin; Huang Guirong; Zhang Pengfei; Li Weimin; Liu Zuping; He Duohui

    2005-01-01

    The two injection ways of new RF system of Hefei storage ring were discussed. In the process of both large detuning injection and tuning injection, the variation of tuning angle and visual detuning angle with beam current intensity was analyzed. The calculation results show that the two injection ways are manipulable for new RF system in phase II project of Hefei storage ring. (author)

  11. Design considerations for a feedback system to control self-bunching in ion-storage rings

    International Nuclear Information System (INIS)

    Ziemann, V.

    2001-02-01

    We discuss the feasibility of a feedback system to cure self-bunching of the electron-cooled coasting ion-beam in CELSIUS. Such a system may also aid stable operation of accumulator rings for future spallation neutron sources or heavy ion rings used for inertial fusion energy production

  12. Status of /hacek C/erenkov Ring Imaging systems

    International Nuclear Information System (INIS)

    Leith, D.W.G.S.

    1987-06-01

    Cerenkov Ring Imaging is briefly introduced, and the problems or choices of designing such a counter are discussed. Recent results from the DELPHI and SLD prototype are presented and compared to the expected performances. 13 refs., 33 figs., 2 tabs

  13. Status of /hacek C/erenkov Ring Imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Leith, D.W.G.S.

    1987-06-01

    Cerenkov Ring Imaging is briefly introduced, and the problems or choices of designing such a counter are discussed. Recent results from the DELPHI and SLD prototype are presented and compared to the expected performances. 13 refs., 33 figs., 2 tabs.

  14. Ring Irrigation System (RIS design through customer preference representation

    Directory of Open Access Journals (Sweden)

    Ridwan Infandra I.Z.

    2018-01-01

    Full Text Available In agricultural field, irrigation is one of the most interesting considerations affecting the rate of plant growth and development. Micro-irrigation as the dripping or sprinkle method is one of the irrigation types that applies the small amount of water for fulfilling the humidity requirement. The most important factors affecting the demand of water for plants are soil conditions and effect of climatic factors. With less human labour required, to improve the irrigation method from the recent days, analyzing water used or water permeation automatically through the soil moisture has been raised as the interesting topic. Proposed in this research is the ring irrigation system (RIS which is introduced as an alternative channel for emitters that drip water directly onto the soil at the plant’s root zone where the soil conditions before and after watering can be quickly detected by the sensors. This RIS can be used for the potted plant, green house, or other small farm fields. Product design and development (PDD is applied in this research for assisting the designer to understand and create the RIS prototype properly according to the customer’s requirements where the suggested functions obtained will be added and tested.

  15. Elliptically fibered Calabi–Yau manifolds and the ring of Jacobi forms

    Directory of Open Access Journals (Sweden)

    Min-xin Huang

    2015-09-01

    Full Text Available We give evidence that the all genus amplitudes of topological string theory on compact elliptically fibered Calabi–Yau manifolds can be written in terms of meromorphic Jacobi forms whose weight grows linearly and whose index grows quadratically with the base degree. The denominators of these forms have a simple universal form with the property that the poles of the meromorphic form lie only at torsion points. The modular parameter corresponds to the fibre class while the role of the string coupling is played by the elliptic parameter. This leads to very strong all genus results on these geometries, which are checked against results from curve counting.

  16. Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing [Xiamen University of Technology, Xiamen (China)

    2017-07-15

    Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

  17. Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

    International Nuclear Information System (INIS)

    Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing

    2017-01-01

    Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

  18. Dissecting the intensely star-forming clumps in a z ~ 2 Einstein Ring

    Science.gov (United States)

    Rujopakarn, Wiphu

    2013-10-01

    Clumps of star formation spreading widely in galactic disks are common features of star-forming galaxies at 1 test cases to study the mechanism that drives intense star formation at z ~ 2. We propose WFC3 near-IR imaging and spatially-resolved spectroscopy of a gravitationally lensed, kinematically ordered, vigorously star-forming galaxy at z = 1.885 with physical resolutions up to 40 pc. This galaxy contains two luminous clumps that are forming stars at the rates of 100 solar mass/yr/clump. Spatially-resolved map of star formation from HST provides the most critical missing piece to interpret our existing observations of this galaxy in far-IR, CO emission lines, and radio continuum. We will probe the frontier research areas in z ~ 2 star formation, particularly the spatially-resolved star formation laws and dynamics of cold and ionized gases, which have never been probed at this spatial resolution. Our proposed observations will provide a benchmark against which to interpret the structures of vigorous star-forming clumps in general. This object can therefore have a unique impact on our understanding of the star-forming modes that dominate at z ~ 2.

  19. Real-time track-less Cherenkov ring fitting trigger system based on Graphics Processing Units

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Chiozzi, S.; Cretaro, P.; Cotta Ramusino, A.; Di Lorenzo, S.; Fantechi, R.; Fiorini, M.; Frezza, O.; Gianoli, A.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Piccini, M.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Vicini, P.

    2017-12-01

    The parallel computing power of commercial Graphics Processing Units (GPUs) is exploited to perform real-time ring fitting at the lowest trigger level using information coming from the Ring Imaging Cherenkov (RICH) detector of the NA62 experiment at CERN. To this purpose, direct GPU communication with a custom FPGA-based board has been used to reduce the data transmission latency. The GPU-based trigger system is currently integrated in the experimental setup of the RICH detector of the NA62 experiment, in order to reconstruct ring-shaped hit patterns. The ring-fitting algorithm running on GPU is fed with raw RICH data only, with no information coming from other detectors, and is able to provide more complex trigger primitives with respect to the simple photodetector hit multiplicity, resulting in a higher selection efficiency. The performance of the system for multi-ring Cherenkov online reconstruction obtained during the NA62 physics run is presented.

  20. Fano and Dicke effects in a double Rashba-ring system

    International Nuclear Information System (INIS)

    Apel, V M; Orellana, P A; Pacheco, M

    2008-01-01

    The electronic transport in a system of two quantum rings side-coupled to a quantum wire is studied via a single-band tunneling tight-binding Hamiltonian. We derived analytical expressions for the conductance and spin polarization when the rings are threaded by magnetic fluxes with Rashba spin-orbit interaction. We show that by using the Fano and Dicke effects this system can be used as an efficient spin filter even for small spin-orbit interaction and small values of magnetic fluxes. We compare the spin-dependent polarization of this design and the polarization obtained with one ring side-coupled to a quantum ring. As a main result, we find better spin polarization capabilities as compared to the one-ring design

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

    International Nuclear Information System (INIS)

    Alfven, H.

    1983-04-01

    The paper is based on Holbergs analysis of the Voyager photographs in both reflected and transparent light, combined with occulation data of stars seen through the rings. Besides rapidly varying phenomena (spokes, braided ring, etc.), which according to Mendis are due to gravito-electromagnetic effects, the ring consists of a bulk structure, a fine structure, and also a hyperfine structure, showing more than 10000 ringlets. The large number of ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interprete 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 (co-orbiting satellites) and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase (which probably took place 4-5 times 10 9 years ago). Further, Holberg has discovered that the shadows are not simple void regions but exhibit a certain characteristic signature. This is not yet understood theoretically. Parts of the fine structure are explained by Holberg as resonances with the satellites. Parts are here interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. The most important conclusion is that an analysis of the ring data is liekly to lead to a reconstruction of the plasma-planetesimal transition with an accuracy of a few percent. (author)

  2. Twin-cutter form turning of commutator rings using cutters’ progressive motion piezoelectric engines

    Directory of Open Access Journals (Sweden)

    Vozhzhov Andrey

    2017-01-01

    Full Text Available The option of realization of the technological scheme of twin-cutter form turning via use of piezoelectric engines of progressive motion is hereby proposed. The cutting force vector constitutes the external perturbation effect. The scheme, design, transfer function of the cutter's piezoelectric engine of progressive motion is hereby presented.

  3. Various vibration modes in a silicon ring resonator driven by p–n diode actuators formed in the lateral direction

    Science.gov (United States)

    Tsushima, Takafumi; Asahi, Yoichi; Tanigawa, Hiroshi; Furutsuka, Takashi; Suzuki, Kenichiro

    2018-06-01

    In this paper, we describe p–n diode actuators that are formed in the lateral direction on resonators. Because previously reported p–n diode actuators, which were driven by a force parallel to the electrostatic force induced in a p–n diode, were fabricated in the perpendicular direction to the surface, the fabrication process to satisfy the requirement of realizing a p–n junction set in the middle of the plate thickness has been difficult. The resonators in this work are driven by p–n diodes formed in the lateral direction, making the process easy. We have fabricated a silicon ring resonator that has in-plane vibration using p–n–p and n–p–n diode actuators formed in the lateral direction. First, we consider a space charge model that can sufficiently accurately describe the force induced in p–n diode actuators and compare it with the capacitance model used in most computer simulations. Then, we show that multiplying the vibration amplitude calculated by computer simulation by the modification coefficient of 4/3 provides the vibration amplitude in the p–n diode actuators. Good agreement of the theory with experimental results of the in-plane vibration measured for silicon ring resonators is obtained. The computer simulation is very useful for evaluating various vibration modes in resonators driven by the p–n diode actuators. The small amplitude of the p–n diode actuator measured in this work is expected to increase greatly with increased doping of the actuator.

  4. The Chlamydia type III secretion system C-ring engages a chaperone-effector protein complex.

    Directory of Open Access Journals (Sweden)

    Kris E Spaeth

    2009-09-01

    Full Text Available In Gram-negative bacterial pathogens, specialized chaperones bind to secreted effector proteins and maintain them in a partially unfolded form competent for translocation by type III secretion systems/injectisomes. How diverse sets of effector-chaperone complexes are recognized by injectisomes is unclear. Here we describe a new mechanism of effector-chaperone recognition by the Chlamydia injectisome, a unique and ancestral line of these evolutionarily conserved secretion systems. By yeast two-hybrid analysis we identified networks of Chlamydia-specific proteins that interacted with the basal structure of the injectisome, including two hubs of protein-protein interactions that linked known secreted effector proteins to CdsQ, the putative cytoplasmic C-ring component of the secretion apparatus. One of these protein-interaction hubs is defined by Ct260/Mcsc (Multiple cargo secretion chaperone. Mcsc binds to and stabilizes at least two secreted hydrophobic proteins, Cap1 and Ct618, that localize to the membrane of the pathogenic vacuole ("inclusion". The resulting complexes bind to CdsQ, suggesting that in Chlamydia, the C-ring of the injectisome mediates the recognition of a subset of inclusion membrane proteins in complex with their chaperone. The selective recognition of inclusion membrane proteins by chaperones may provide a mechanism to co-ordinate the translocation of subsets of inclusion membrane proteins at different stages in infection.

  5. Electron beam extraction system with a ring radiation field

    International Nuclear Information System (INIS)

    Auslender, V.L.; Kuksanov, N.K.; Polyakov, V.A.; Salimov, R.A.; Chertok, I.L.

    1979-01-01

    Description and results of testings of two electron beam extraction systems for shaping of a circular irradiation field are given. One of the systems contains three 20 cm long outlet windows arranged at 120 deg angle with respect to each other. Tests at the ILU-6 accelerator have shown that the given system provides 150 mm zone irradiation from three sides. Beam utilization factor when irradiating three 40 mm dia tubes amounted to 35% which provides capacity of 2.5 txMrad/h at 20 kW beam power. The other extraction system includes two C-form magnets producing nonuniform and opposing magnetic fields. This system tests at the EhLV-2 accelerator have shown that at 0.8-1.5 MeV electron energy it is possible to irradiate of 60 and 100 mm dia objects, accordingly. The system may be used together with both constant-action and pulse-action accelerators having extraction with linear scanning [ru

  6. Experience of usage of forming rings and protective caps made of PTFE on the single-component implants

    Directory of Open Access Journals (Sweden)

    S. A. Chertov

    2014-04-01

    Full Text Available Relevance. The main reason that limits the usage of single-component implants, as compared with collapsible (two-component implants is the high risk of infectious and inflammatory complications in the postoperative period and problems in prosthetics in the esthetically important areas. Therefore, the usage of elements that contribute to healing of the mucous membrane in the early stages of implantation is particularly up-to-date. Work objective is to determine the clinical effectiveness of usage of forming rings and protective caps made of PTFE on the single-component implants in the prevention of peri-implant pathology on a one-step surgical implantation. Materials and methods of the investigation. For this work we used the treatment results of 24 patients with various dentition defects. According to the single-component implant procedure 52 single-component implants were mounted. The head of monolithic implants (38 p. were isolated by rings or caps made of PTFE. For comparison, 14 implants remained bare for 2-6 weeks before the temporary prosthesis. Postoperatively, subjective feelings were noted in patients, the presence or absence of pain complaints during the examination and palpation, the nature and extent of edema, the phenomena of inflammation around the implant neck were checked. At the stage of sutures removal the degree of soft plaque deposits on the healing elements and titanium implant heads was assessed. Results of the investigation and their discussion. No effects of mucosal hyperemia around the supporting elements made of PTFE were revealed, there was no soft and hard plaque on the rings and caps in most patients of the main group. In patients of the control group, on the contrary, the appearance of the biofilm that covered the head and the implant shoulder on all abutments, which were not protected by a ring or cap, was noted. The healing period of mucous membrane in patients of the control group was longer, the quality of

  7. Single-pass BPM system of the Photon Factory storage ring.

    Science.gov (United States)

    Honda, T; Katoh, M; Mitsuhashi, T; Ueda, A; Tadano, M; Kobayashi, Y

    1998-05-01

    At the 2.5 GeV ring of the Photon Factory, a single-pass beam-position monitor (BPM) system is being prepared for the storage ring and the beam transport line. In the storage ring, the injected beam position during the first several turns can be measured with a single injection pulse. The BPM system has an adequate performance, useful for the commissioning of the new low-emittance lattice. Several stripline BPMs are being installed in the beam transport line. The continuous monitoring of the orbit in the beam transport line will be useful for the stabilization of the injection energy as well as the injection beam orbit.

  8. The simulation of control system for the KEK main ring power supply, 1

    International Nuclear Information System (INIS)

    Sato, Hikaru; Shintomi, Takakazu; Kubo, Tadashi; Masuda, Masayoshi; Nakano, Michio.

    1975-09-01

    The simulation of control system for the KEK main ring power supply is performed. The inductance of the magnet is assumed to be linear against to the current. The results of the simulations are described. (auth.)

  9. Domino Wittig Diels-Alder reaction: An expeditious entry into the AB ring system of furanosesquiterpenes

    Digital Repository Service at National Institute of Oceanography (India)

    Patre, R.E.; Gawas, S.; Sen, S.; Parameswaran, P.S.; Tilve, S.G.

    A domino Wittig Diels - Alder reaction has been employed in delineating a short and flexible synthetic stratagem for ready access to the AB ring system and the tricyclic framework of furanosesquiterpenes, such as the bioactive natural products...

  10. A Saturn Ring Observer Mission Using Multi-Mission Radioisotope Power Systems

    International Nuclear Information System (INIS)

    Abelson, Robert D.; Spilker, Thomas R.; Shirley, James H.

    2006-01-01

    Saturn remains one of the most fascinating planets within the solar system. To better understand the complex ring structure of this planet, a conceptual Saturn Ring Observer (SRO) mission is presented that would spend one year in close proximity to Saturn's A and B rings, and perform detailed observations and measurements of the ring particles and electric and magnetic fields. The primary objective of the mission would be to understand ring dynamics, including the microphysics of individual particles and small scale (meters to a few kilometers) phenomena such as particle agglomeration behavior. This would be accomplished by multispectral imaging of the rings at multiple key locations within the A and B rings, and by ring-particle imaging at an unprecedented resolution of 0.5 cm/pixel. The SRO spacecraft would use a Venus-Earth-Earth-Jupiter Gravity Assist (VEEJGA) and be aerocaptured into Saturn orbit using an advanced aeroshell design to minimize propellant mass. Once in orbit, the SRO would stand off from the ring plane 1 to 1.4 km using chemical thrusters to provide short propulsive maneuvers four times per revolution, effectively causing the SRO vehicle to 'hop' above the ring plane. The conceptual SRO spacecraft would be enabled by the use of a new generation of multi-mission Radioisotope Power Systems (RPSs) currently being developed by NASA and DOE. These RPSs include the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and Stirling Radioisotope Generator (SRG). The RPSs would generate all necessary electrical power (≥330 We at beginning of life) during the 10-year cruise and 1-year science mission (∼11 years total). The RPS heat would be used to maintain the vehicle's operating and survival temperatures, minimizing the need for electrical heaters. Such a mission could potentially launch in the 2015-2020 timeframe, with operations at Saturn commencing in approximately 2030

  11. The Abort Kicker System for the PEP-II Storage Rings at SLAC

    International Nuclear Information System (INIS)

    Delamare, Jeffrey E

    2003-01-01

    The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of election beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 (micro)S (the beam transit time around the ring). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% while there is no beam in the kicker magnet. Originally the kicker system was designed for a rise time of 370nS [1], but because the ion clearing gap was reduced in half, so was the rise time requirement for the kicker. This report discusses the design of the system interlocks, diagnostics, and modulator with the modifications necessary to accommodate an ion clearing gap of 185nS

  12. Simulation of Small Wind Turbine Generation System Using Ring Winding Slotless PMSG by FEM

    OpenAIRE

    徳永, 翔平; 袈裟丸, 勝己; Tokunaga, Shohei; Kesamaru, Katsumi

    2011-01-01

    This paper describes a novel small wind turbine generation system with ring winding slotless PMSG. To reduce cogging torque, ring winding PM generator is used for a wind turbine generator. Using finite element analysis, the characteristics of slotless PMSGs are elucidated and the dynamic performance of the proposed system with MPPT control is represented. In this paper, the constant wind test and the quasi-natural wind test are conducted. The results of these tests indicate the proposed syste...

  13. Dragging of inertial frames in the composed black-hole-ring system

    International Nuclear Information System (INIS)

    Hod, Shahar

    2015-01-01

    A well-established phenomenon in general relativity is the dragging of inertial frames by a spinning object. In particular, due to the dragging of inertial frames by a ring orbiting a central black hole, the angular velocity Ω H BH-ring of the black-hole horizon in the composed black-hole-ring system is no longer related to the black-hole angular momentum J H by the simple Kerr-like (vacuum) relation Ω H Kerr (J H ) = J H /2M 2 R H (here M and R H are the mass and horizon-radius of the black hole, respectively). Will has performed a perturbative treatment of the composed black-hole-ring system in the regime of slowly rotating black holes and found the explicit relation Ω H BH-ring (J H = 0, J R , R) = 2J R /R 3 for the angular velocity of a central black hole with zero angular momentum, where J R and R are respectively the angular momentum of the orbiting ring and its proper circumferential radius. Analyzing a sequence of black-hole-ring configurations with adiabatically varying (decreasing) circumferential radii, we show that the expression found by Will for Ω H BH-ring (J H = 0, J R , R) implies a smooth transition of the central black-hole angular velocity from its asymptotic near-horizon value Ω H BH-ring (J H = 0, J R , R → R H + ) → 2J R /R H 3 (that is, just before the assimilation of the ring by the central black hole), to its final Kerr (vacuum) value Ω H Kerr (J H new )= J H new /2M new2 R H new [that is, after the adiabatic assimilation of the ring by the central black hole. Here J H new = J R , M new , and R H new are the new parameters of the resulting Kerr (vacuum) black hole after it assimilated the orbiting ring]. We use this important observation in order to generalize the result of Will to the regime of black-hole-ring configurations in which the central black holes possess non-zero angular momenta. In particular, it is shown that the continuity argument (namely, the characteristic smooth evolution of the black-hole angular velocity

  14. Dragging of inertial frames in the composed black-hole-ring system

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Institute, Jerusalem (Israel)

    2015-11-15

    A well-established phenomenon in general relativity is the dragging of inertial frames by a spinning object. In particular, due to the dragging of inertial frames by a ring orbiting a central black hole, the angular velocity Ω{sub H}{sup BH-ring} of the black-hole horizon in the composed black-hole-ring system is no longer related to the black-hole angular momentum J{sub H} by the simple Kerr-like (vacuum) relation Ω{sub H}{sup Kerr}(J{sub H}) = J{sub H}/2M{sup 2}R{sub H} (here M and R{sub H} are the mass and horizon-radius of the black hole, respectively). Will has performed a perturbative treatment of the composed black-hole-ring system in the regime of slowly rotating black holes and found the explicit relation Ω{sub H}{sup BH-ring}(J{sub H} = 0, J{sub R}, R) = 2J{sub R}/R{sup 3} for the angular velocity of a central black hole with zero angular momentum, where J{sub R} and R are respectively the angular momentum of the orbiting ring and its proper circumferential radius. Analyzing a sequence of black-hole-ring configurations with adiabatically varying (decreasing) circumferential radii, we show that the expression found by Will for Ω{sub H}{sup BH-ring}(J{sub H} = 0, J{sub R}, R) implies a smooth transition of the central black-hole angular velocity from its asymptotic near-horizon value Ω{sub H}{sup BH-ring}(J{sub H} = 0, J{sub R}, R → R{sub H}{sup +}) → 2J{sub R}/R{sub H}{sup 3} (that is, just before the assimilation of the ring by the central black hole), to its final Kerr (vacuum) value Ω{sub H}{sup Kerr}(J{sub H}{sup new})= J{sub H}{sup new}/2M{sup new2}R{sub H}{sup new} [that is, after the adiabatic assimilation of the ring by the central black hole. Here J{sub H}{sup new} = J{sub R}, M{sup new}, and R{sub H}{sup new} are the new parameters of the resulting Kerr (vacuum) black hole after it assimilated the orbiting ring]. We use this important observation in order to generalize the result of Will to the regime of black-hole-ring configurations

  15. Dragging of inertial frames in the composed black-hole–ring system

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar, E-mail: shaharhod@gmail.com [The Ruppin Academic Center, 40250, Emeq Hefer (Israel); The Hadassah Institute, 91010, Jerusalem (Israel)

    2015-11-19

    A well-established phenomenon in general relativity is the dragging of inertial frames by a spinning object. In particular, due to the dragging of inertial frames by a ring orbiting a central black hole, the angular velocity Ω{sub H}{sup BH-ring} of the black-hole horizon in the composed black-hole–ring system is no longer related to the black-hole angular momentum J{sub H} by the simple Kerr-like (vacuum) relation Ω{sub H}{sup Kerr}(J{sub H})=J{sub H}/2M{sup 2}R{sub H} (here M and R{sub H} are the mass and horizon-radius of the black hole, respectively). Will has performed a perturbative treatment of the composed black-hole–ring system in the regime of slowly rotating black holes and found the explicit relation Ω{sub H}{sup BH-ring}(J{sub H}=0,J{sub R},R)=2J{sub R}/R{sup 3} for the angular velocity of a central black hole with zero angular momentum, where J{sub R} and R are respectively the angular momentum of the orbiting ring and its proper circumferential radius. Analyzing a sequence of black-hole–ring configurations with adiabatically varying (decreasing) circumferential radii, we show that the expression found by Will for Ω{sub H}{sup BH-ring}(J{sub H}=0,J{sub R},R) implies a smooth transition of the central black-hole angular velocity from its asymptotic near-horizon value Ω{sub H}{sup BH-ring}(J{sub H}=0,J{sub R},R→R{sub H}{sup +})→2J{sub R}/R{sub H}{sup 3} (that is, just before the assimilation of the ring by the central black hole), to its final Kerr (vacuum) value Ω{sub H}{sup Kerr}(J{sub H}{sup new})=J{sub H}{sup new}/2M{sup new2}R{sub H}{sup new} [that is, after the adiabatic assimilation of the ring by the central black hole. Here J{sub H}{sup new}=J{sub R}, M{sup new}, and R{sub H}{sup new} are the new parameters of the resulting Kerr (vacuum) black hole after it assimilated the orbiting ring]. We use this important observation in order to generalize the result of Will to the regime of black-hole–ring configurations in which the

  16. The Abort Kicker System for the PEP-II Storage Rings at SLAC.

    CERN Document Server

    Delamare, J E

    2003-01-01

    The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of election beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 (micro)S (the beam transit time around the ring). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% while there is no beam in the kicker magnet. Originally the kicker system was designed for a rise time of 370nS [1], but because the ion clearing gap was reduced in half, so was the rise time requirement for the kicker. This report discusses the des...

  17. Slab edge insulating form system and methods

    Science.gov (United States)

    Lee, Brain E [Corral de Tierra, CA; Barsun, Stephan K [Davis, CA; Bourne, Richard C [Davis, CA; Hoeschele, Marc A [Davis, CA; Springer, David A [Winters, CA

    2009-10-06

    A method of forming an insulated concrete foundation is provided comprising constructing a foundation frame, the frame comprising an insulating form having an opening, inserting a pocket former into the opening; placing concrete inside the foundation frame; and removing the pocket former after the placed concrete has set, wherein the concrete forms a pocket in the placed concrete that is accessible through the opening. The method may further comprise sealing the opening by placing a sealing plug or sealing material in the opening. A system for forming an insulated concrete foundation is provided comprising a plurality of interconnected insulating forms, the insulating forms having a rigid outer member protecting and encasing an insulating material, and at least one gripping lip extending outwardly from the outer member to provide a pest barrier. At least one insulating form has an opening into which a removable pocket former is inserted. The system may also provide a tension anchor positioned in the pocket former and a tendon connected to the tension anchor.

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

    Science.gov (United States)

    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.

  19. Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples.

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    Full Text Available The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width.

  20. An Automatic Assembling System for Sealing Rings Based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Mingyu Gao

    2017-01-01

    Full Text Available In order to grab and place the sealing rings of battery lid quickly and accurately, an automatic assembling system for sealing rings based on machine vision is developed in this paper. The whole system is composed of the light sources, cameras, industrial control units, and a 4-degree-of-freedom industrial robot. Specifically, the sealing rings are recognized and located automatically with the machine vision module. Then industrial robot is controlled for grabbing the sealing rings dynamically under the joint work of multiple control units and visual feedback. Furthermore, the coordinates of the fast-moving battery lid are tracked by the machine vision module. Finally the sealing rings are placed on the sealing ports of battery lid accurately and automatically. Experimental results demonstrate that the proposed system can grab the sealing rings and place them on the sealing port of the fast-moving battery lid successfully. More importantly, the proposed system can improve the efficiency of the battery production line obviously.

  1. An Alternative Derivation of the Energy Levels of the "Particle on a Ring" System

    Science.gov (United States)

    Vincent, Alan

    1996-10-01

    All acceptable wave functions must be continuous mathematical functions. This criterion limits the acceptable functions for a particle in a linear 1-dimensional box to sine functions. If, however, the linear box is bent round into a ring, acceptable wave functions are those which are continuous at the 'join'. On this model some acceptable linear functions become unacceptable for the ring and some unacceptable cosine functions become acceptable. This approach can be used to produce a straightforward derivation of the energy levels and wave functions of the particle on a ring. These simple wave mechanical systems can be used as models of linear and cyclic delocalised systems such as conjugated hydrocarbons or the benzene ring. The promotion energy of an electron can then be used to calculate the wavelength of absorption of uv light. The simple model gives results of the correct order of magnitude and shows that, as the chain length increases, the uv maximum moves to longer wavelengths, as found experimentally.

  2. A new form of Ca{sub 3}P{sub 2} with a ring of Dirac nodes

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Lilia S.; Schoop, Leslie M.; Seibel, Elizabeth M.; Gibson, Quinn D.; Xie, Weiwei; Cava, Robert J., E-mail: rcava@princeton.edu [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

    2015-08-01

    We report the synthesis and crystal structure of a new high-temperature form of Ca{sub 3}P{sub 2}. The crystal structure was determined through Rietveld refinements of synchrotron powder x-ray diffraction data. This form of Ca{sub 3}P{sub 2} has a crystal structure of the hexagonal Mn{sub 5}Si{sub 3} type, with a Ca ion deficiency compared to the ideal 5:3 stoichiometry. This yields a stable, charge-balanced compound of Ca{sup 2+} and P{sup 3−}. We also report the observation of a secondary hydride phase, Ca{sub 5}P{sub 3}H, which again is a charge-balanced compound. The calculated band structure of Ca{sub 3}P{sub 2} indicates that it is a three-dimensional Dirac semimetal with a highly unusual ring of Dirac nodes at the Fermi level. The Dirac states are protected against gap opening by a mirror plane in a manner analogous to what is seen for graphene.

  3. Possibility of persistent voltage observation in a system of asymmetric superconducting rings

    International Nuclear Information System (INIS)

    Burlakov, A.A.; Gurtovoi, V.L.; Ilin, A.I.; Nikulov, A.V.; Tulin, V.A.

    2012-01-01

    The possibility of observing persistent voltage in superconducting rings of different arm widths is experimentally investigated. It was previously found that switching of the arms between superconducting and normal states by an AC current induces DC voltage oscillation in the magnetic field with a period corresponding to the flux quantum inside the ring. We used systems with a large number of asymmetric rings connected in series to investigate the possibility of observing this quantum phenomenon near the superconducting transition, where thermal fluctuations lead to switching of ring segments without an external influence and the persistent current is much smaller than in the superconducting state. -- Highlights: ► A possibility to observe the persistent voltage is investigated experimentally. ► The persistent voltage is a DC voltage observed at thermodynamic equilibrium. ► It oscillates in magnetic field like the persistent current in superconducting ring. ► The period of the oscillations corresponds to the flux quantum inside the ring. ► The quantum oscillations of the DC voltage were observed on asymmetric rings.

  4. The Centaur Chariklo and its rings system from stellar occultations in 2017

    Science.gov (United States)

    Leiva, Rodrigo; Sicardy, Bruno; Camargo, Julio; Ortiz, Jose Luis; Berard, Diane; Desmars, Josselin; Chariklo Occultations Team; Rio Group; Lucky Star Occultation Team; Granada Occultation Team

    2017-10-01

    A stellar occultation in June 3, 2013 revealed the presence of a dense ring system around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 2014). Subsequent analysis of occultation data and long-term photometric variations indicate that Chariklo's body is elongated (Leiva et al. 2017, submitted) and that the main ring exhibits significant longitudinal variations of the radial width (Bérard et al. 2017, in press). We report three multi-chord high-quality stellar occultation by Chariklo on April 9, 2017 and June 22, 2017 from Namibia, and July 23 2017 from South America. The analysis of this new data set is underway, but preliminary results are consistent with triaxial ellipsoidal models. From this analysis we will:-present refined models for the size and shape of Chariklo's main body andevaluate the heights and slopes of its topographic features.-give constraints on the longitudinal width variations of Chariklo's rings andexplore the possibility to obtain the rings apsidal precession rate.Chariklo's shape and topography have strong consequences on the dynamics of the rings through Lindblad-type resonances between mean motion of the ring particles and the spin of the main body, while the rings precession rate gives constraints on the dynamical oblateness of the main body.**Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ ERC Grant Agreement n 669416 ”LUCKY STAR”).

  5. Simulation of the control system for the KEK main ring power supply-II

    International Nuclear Information System (INIS)

    Kabe, Atsushi; Sato, Hikaru; Masuda, Masayoshi; Takeda, Masahiro; Nakano, Michio

    1977-05-01

    The tracking error between the magnetic field of the bending magnets and that of the quadrupole magnets is a very important problem of the KEK main ring power supply. Tacking performance is simulated using DDS (Digital Dynamics Simulator) in cases of 8 GeV and 12 GeV operation of the KEK main ring. The results of simulation coincide with the data of actual system. (auth.)

  6. Morphological evolution of Ge/Si(001) quantum dot rings formed at the rim of wet-etched pits.

    Science.gov (United States)

    Grydlik, Martyna; Brehm, Moritz; Schäffler, Friedrich

    2012-10-30

    We demonstrate the formation of Ge quantum dots in ring-like arrangements around predefined {111}-faceted pits in the Si(001) substrate. We report on the complex morphological evolution of the single quantum dots contributing to the rings by means of atomic force microscopy and demonstrate that by careful adjustment of the epitaxial growth parameters, such rings containing densely squeezed islands can be grown with large spatial distances of up to 5 μm without additional nucleation of randomly distributed quantum dots between the rings.

  7. Real time global orbit feedback system for NSLS x-ray ring

    International Nuclear Information System (INIS)

    Yu, L.H.; Biscardi, R.; Bittner, J.; Fauchet, A.M.; Krinsky, F.S.; Nawrocky, R.J.; Rothman, J.; Singh, O.V.; Yang, K.M.

    1991-01-01

    We report on the design and commissioning of a real time harmonic global orbit feedback system for the NSLS X-ray ring. This system uses 8 pick-up electrode position monitors and 16 trim dipole magnets to eliminate 3 harmonic components of the orbit fluctuations. Because of the larger number of position monitors and trim magnets, the X-ray ring feedback system differs from the previously reported VUV ring system in that the Fourier analysis and harmonic generation networks are comprised of MDAC boards controlled by computer. The implementation of the global feedback system has resulted in a dramatic improvement of orbit stability, by more than a factor of five everywhere. Simultaneous operation of the global and several local bump feedback systems has been achieved. 4 refs., 5 figs

  8. Manufacture of the ALS storage ring vacuum system

    International Nuclear Information System (INIS)

    Kennedy, K.

    1990-11-01

    The Advanced Light Source (ALS) storage rings has a 4.9 meter magnetic radius and an antechamber type vacuum chamber. These two requirements makes conventional bent tube manufacturing techniques difficult. The ALS sector vacuum chambers have been made by matching two halves out of aluminum plate and welding at the mid plane. Each of these chambers have over 50 penetrations with metal sealed flanges and seven metal sealed poppet valves which use the chamber wall as the valve seat. The sector chambers are 10 meter long and some features in the chambers must be located to .25 mm. This paper describes how and how successfully these features have been achieved. 2 refs., 5 figs

  9. Modelling a Java Ring based implementation of an N-Count payment system

    NARCIS (Netherlands)

    Revill, J.D.; Hartel, Pieter H.

    N-Count is a system for offline value transfer. A prototype of an N-Count payment system has been designed, and it has been implemented in Java. We have used the Java Ring with the Java Card API as a secure device. The system has also been modelled using the Spin model checker. The combined

  10. Mobile based optical form evaluation system

    Directory of Open Access Journals (Sweden)

    Asım Sinan YÜKSEL

    2016-05-01

    Full Text Available Optical forms that contain multiple-choice answers are widely used both for electing students and evaluating student achievements in education systems in our country and worldwide. Optical forms are evaluated by employing optical mark recognition techniques through optical readers. High cost of these machines, limited access to them, long waiting time for evaluation results make the process hard for educationists working in cities or countries. In this study, a mobile application was developed for the educationists who own mobile phones or tablets for the purpose of evaluating students' answer sheets quickly and independent of location and optical readers. Optical form recognition, reading and evaluation processes are done on the image of student's answer sheet that is taken with the mobile phone or tablet of educationist. The Android based mobile application that we developed has a user-friendly interface, high success rate and is the first of our knowledge application that operates on mobile platforms in this field.

  11. The AGS Booster main ring power supply system

    International Nuclear Information System (INIS)

    Soukas, A.; Hughes, K.; Sandberg, J.; Toldo, F.; Zhang, S.Y.

    1989-01-01

    The AGS Booster is being designed as a very versatile particle accelerator. Its primary function is to be a high quality injector to the currently operating Alternating Gradient Synchrotron (AGS). The Booster/AGS combination will produce proton intensities greater than 5 x 10 13 protons per pulse (ppp), and accelerate heavy ions, with mass up to 200, to a maximum energy of 15 GeV per atomic mass unit (GeV/amu). The power supply for the Booster Main Ring (BMRPS) has to accommodate a wide range of cycles and a wide range of operating parameters. The cycles range from storage for several seconds to rapid cycling at 7.5 Hz. The peak output power is 18 MW. This paper will describe the AGS Booster machine powering requirements, the choice of power supply, the a.c. circuit tie-in and its associated problems and some of the details of the design of the BMRPS. 9 refs., 2 figs

  12. A pinger system for the Los Alamos Proton Storage Ring

    International Nuclear Information System (INIS)

    Hardek, T.W.; Thiessen, H.A.

    1991-01-01

    Developers at the Proton Storage Ring have long desired a modulator and electrode combination capable of kicking the 800-MeV proton beam enough to conduct tune measurements with full intensity beams. At present this has been accomplished by reducing the voltage on one extraction kicker modulator and turning the other off. This method requires that all of the accumulated beam be lost on the walls of the vacuum chamber. In addition to tune measurements a more recent desire is to sweep out beam that may have leaked into the area between bunches. A four-meter electrode has been designed and constructed for the purpose. The design is flexible in that the electrode may be split in the center and rotated in order to provide vertical and horizontal electrodes each 2 meters long. In addition two solid-state pulse modulators that can provide 10kV in burst mode at up to 700 KHz have been purchased. This hardware and its intended use are described. 3 refs., 2 figs., 1 tab

  13. Auto-production of biosurfactants reverses the coffee ring effect in a bacterial system

    Science.gov (United States)

    Sempels, Wouter; de Dier, Raf; Mizuno, Hideaki; Hofkens, Johan; Vermant, Jan

    2013-04-01

    The deposition of material at the edge of evaporating droplets, known as the ‘coffee ring effect’, is caused by a radially outward capillary flow. This phenomenon is common to a wide array of systems including colloidal and bacterial systems. The role of surfactants in counteracting these coffee ring depositions is related to the occurrence of local vortices known as Marangoni eddies. Here we show that these swirling flows are universal, and not only lead to a uniform deposition of colloids but also occur in living bacterial systems. Experiments on Pseudomonas aeruginosa suggest that the auto-production of biosurfactants has an essential role in creating a homogeneous deposition of the bacteria upon drying. Moreover, at biologically relevant conditions, intricate time-dependent flows are observed in addition to the vortex regime, which are also effective in reversing the coffee ring effect at even lower surfactant concentrations.

  14. A Study of Storage Ring Requirements for an Explosive Detection System Using NRA Method

    CERN Document Server

    Wang, Tai-Sen

    2005-01-01

    The technical feasibility of an explosives detection system based on the nuclear resonance absorption (NRA) of gamma rays in nitrogen-rich materials was demonstrated at Los Alamos National Laboratory (LANL) in 1993 by using an RFQ proton accelerator and a tomographic imaging prototype.* The study is being continued recently to examine deployment of such an active interrogation system in realistic scenarios. The approach is to use a cyclotron and electron-cooling-equipped storage rings(s) to provide the high quality and high current proton beam needed in a practical application. In this work, we investigate the storage ring requirements for a variant of the airport luggage inspection system considered in the earlier LANL experiments. Estimations are carried out based on the required inspection throughput, the gamma ray yield, the proton beam emittance growth due to scattering with the photon-production target, beam current limit in the storage ring, and the electron cooling rate. Studies using scaling and reas...

  15. Testing reachability and stabilizability of systems over polynomial rings using Gröbner bases

    NARCIS (Netherlands)

    Habets, L.C.G.J.M.

    1993-01-01

    Conditions for the reachability and stabilizability of systems over polynomial rings are well-known in the literature. For a system $ \\Sigma = (A,B)$ they can be expressed as right-invertibility cconditions on the matrix $(zI - A \\mid B)$. Therefore there is quite a strong algebraic relationship

  16. An application of ultrasonic inspection system (INER-SCAN) inspecting generator retaining rings

    International Nuclear Information System (INIS)

    Chen, L.C.; Hwang, S.C.

    1994-01-01

    The performances of the automatic ultrasonic inspecting and imaging system (INER-SCAN) developed by the NDT laboratory of the Institute of Nuclear Energy Research have been enhanced and much more improved to commercial level. With appropriate rearrangements of software libraries, it is used to inspect generator retaining rings which are critical structural rotor components that support the end-turn regions of the rotor wingings against centrifugal forces. The use of the INER-SCAN provides distinct advantages over other systems in terms of the reliability of inspection and the flexibility of system performance modifications. The INER-SCAN system assists users to select and modify ultrasonic parameters under computer-aided environment. In addition, the INER-SCAN system contains the necessary software functions to image the ultrasonic data (A-SCAN, B-SCAN, B'-SCAN, C-SCAN). The use of the imaging system makes it quite easy to evaluate various test parameters and their effects on the discrimination between geometric and IGSCC reflectors. Through experimental test, it is recognized that the system has powerful detectable capability which can find 0.2mm-depth slight scratch on the inner surface of retaining rings. This system can also be used on different generator retaining rings (different in terms of hidden design features) without the need for access to the dimension of retaining ring

  17. A Study of Storage Ring Requirements for an Explosive Detection System Using NRA Method.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T. F. (Tai-Sen F.); Kwan, T. J. T. (Thomas J. T.)

    2005-01-01

    The technical feasibility of an explosives detection system based on the nuclear resonance absorption (NRA) of gamma rays in nitrogen-rich materials was demonstrated at Los Alamos National Laboratory (LANL) in 1993 by using an RFQ proton accelerator and a tomographic imaging prototype. The study is being continued recently to examine deployment of such an active interrogation system in realistic scenarios. The approach is to use an accelerator and electron-cooling-equipped storage rings(s) to provide the high quality and high current proton beam needed in a practical application. In this work, we investigate the requirements on the storage ring(s) with external gamma-ray-production target for a variant of the airport luggage inspection system considered in the earlier LANL experiments. Estimations are carried out based on the required inspection throughput, the gamma ray yield, the proton beam emittance growth due to scatters with the photon-production target, beam current limit in the storage ring, and the electron-cooling rate. Studies using scaling and reasonable parameter values indicate that it is possible to use no more than a few storage rings per inspection station in a practical NRA luggage inspection complex having more than ten inspection stations.

  18. Design for ANL 7 GeV storage ring vacuum system

    International Nuclear Information System (INIS)

    Wehrle, R.B.; Nielsen, R.W.

    1988-01-01

    The 7-GeV Advanced Photon Source (APS) design includes a storage ring having a 1060-m circumference with the capability of accommodating 34 insertion devices (ID) and their associated photon beam lines. An additional 35 photon lines can be provided from bending magnets. The vacuum system for the storage ring is designed to maintain a beam-on operating pressure of 1n Torr or less to achieve a positron beam lifetime of approximately 20 hours. The vacuum system and it's current developmental status are described

  19. A chromia forming thermal barrier coating system

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, M.P.; Evans, H.E. [Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT (United Kingdom); Gray, S.; Nicholls, J.R. [Surface Science and Engineering Centre, Cranfield University, Cranfield, MK43 0AL (United Kingdom)

    2011-07-15

    Conventional thermal barrier coating (TBC) systems consist of an insulating ceramic topcoat, a bond coat for oxidation protection and the underlying superalloy designed to combat the oxidising conditions in aero- and land-based gas turbines. Under high-temperature oxidation, the use of an alumina forming bond coat is warranted, thus all current TBC systems are optimised for the early formation of a dense, protective thermally grown oxide (TGO) of alumina. This also offers protection against Type I hot corrosion but a chromia layer gives better protection against Type II corrosion and intermediate temperatures, the conditions found in land-based gas turbines. In this paper the authors present the first known results for a chromia forming TBC system. Tests have been performed under oxidising conditions, up to 1000 h, at temperatures between 750 C and 900 C, and under Type I (900 C) and Type II (700 C) hot corrosion conditions up to 500 h. Under all these conditions no cracking, spallation or degradation was observed. Examination showed the formation of an adherent, dense chromia TGO at the bond coat / topcoat interface. These initial results are very encouraging and the TGO thicknesses agree well with comparable results reported in the literature. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Tribo-systems for Sheet Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels

    2009-01-01

    The present paper gives an overview of more than 10 years work by the author’s research group through participation in national as well as international framework programmes on developing and testing environmentally friendly lubricants and tool materials and coatings inhibiting galling. Partners ......’s research group has especially been involved in the development of a system of tribo-tests for sheet metal forming and in testing and modelling of friction and limits of lubrication of new, environmentally friendly lubricants and tool materials....

  1. Pediatric scleroderma: systemic or localized forms.

    Science.gov (United States)

    Torok, Kathryn S

    2012-04-01

    Pediatric scleroderma includes 2 major groups of clinical entities, systemic sclerosis (SSc) and localized scleroderma (LS). Although both share a common pathophysiology, their clinical manifestations differ. LS is typically confined to the skin and underlying subcutis, with up to a quarter of patients showing extracutaneous disease manifestations such as arthritis and uveitis. Vascular, cutaneous, gastrointestinal, pulmonary, and musculoskeletal involvement are most commonly seen in children with SSc. Treatment of both forms targets the active inflammatory stage and halts disease progression; however, progress needs to be made toward the development of more effective antifibrotic therapy to help reverse disease damage. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Block Fusion Systems and the Center of the Group Ring

    DEFF Research Database (Denmark)

    Jacobsen, Martin Wedel

    This thesis develops some aspects of the theory of block fusion systems. Chapter 1 contains a brief introduction to the group algebra and some simple results about algebras over a field of positive characteristic. In chapter 2 we define the concept of a fusion system and the fundamental property...... of saturation. We also define block fusion systems and prove that they are saturated. Chapter 3 develops some tools for relating block fusion systems to the structure of the center of the group algebra. In particular, it is proven that a block has trivial defect group if and only if the center of the block...... algebra is one-dimensional. Chapter 4 consists of a proof that block fusion systems of symmetric groups are always group fusion systems of symmetric groups, and an analogous result holds for the alternating groups....

  3. Electromagnetic form factors of composite systems

    International Nuclear Information System (INIS)

    Nowak, E.J.

    1978-01-01

    Electromagnetic form factors are examined for a spin-zero, two-body composite system with emphasis on the case of small momentum transfer and/or deep (relativistic) binding. Perturbation theory calculations are first performed using spin-zero and then spin-one-half constituents. A dispersion representation of the bound-state vertex function is conjectured first for scalar and then for fermion constituents. Then a relativistic effective range approximation (RERA) is developed for each case and applied to the calculation of the electromagnetic form factor. The approach is applied to the study of the charge radii of the K 0 and K + mesons. The K/sub l3/ form factor is calculated in the fermion constituent RERA model, and restrictions are imposed on the model parameters from available experimental data. With these restrictions the limits 0.24fm less than or equal to √[abs. value ( 2 >/sub K 0 /)] less than or equal to = 0.36fm and 0.66fm less than or equal to = √( 2 >/sub K + /) less than or equal to 0.79fm are obtained for the kaon charge radii, and -.22 less than or equal to xi less than or equal to -.13 is found for the ratio of the neutral to charged kaon charge radius squared

  4. An analog RF gap voltage regulation system for the Advanced Photon Source storage ring

    International Nuclear Information System (INIS)

    Horan, D.

    1999-01-01

    An analog rf gap voltage regulation system has been designed and built at Argonne National Laboratory to maintain constant total storage ring rf gap voltage, independent of beam loading and cavity tuning effects. The design uses feedback control of the klystron mod-anode voltage to vary the amount of rf power fed to the storage ring cavities. The system consists of two independent feedback loops, each regulating the combined rf gap voltages of eight storage ring cavities by varying the output power of either one or two rf stations, depending on the mode of operation. It provides full operator control and permissive logic to permit feedback control of the rf system output power only if proper conditions are met. The feedback system uses envelope-detected cavity field probe outputs as the feedback signal. Two different methods of combining the individual field probe signals were used to generate a relative DC level representing one-half of the total storage ring rf voltage, an envelope-detected vector sum of the field probe rf signals, and the DC sum of individual field probe envelope detector outputs. The merits of both methods are discussed. The klystron high-voltage power supply (HVPS) units are fitted with an analog interface for external control of the mod-anode voltage level, using a four-quadrant analog multiplier to modulate the HVPS mod-anode voltage regulator set-point in response to feedback system commands

  5. Embedding the dynamics of a single delay system into a feed-forward ring.

    Science.gov (United States)

    Klinshov, Vladimir; Shchapin, Dmitry; Yanchuk, Serhiy; Wolfrum, Matthias; D'Huys, Otti; Nekorkin, Vladimir

    2017-10-01

    We investigate the relation between the dynamics of a single oscillator with delayed self-feedback and a feed-forward ring of such oscillators, where each unit is coupled to its next neighbor in the same way as in the self-feedback case. We show that periodic solutions of the delayed oscillator give rise to families of rotating waves with different wave numbers in the corresponding ring. In particular, if for the single oscillator the periodic solution is resonant to the delay, it can be embedded into a ring with instantaneous couplings. We discover several cases where the stability of a periodic solution for the single unit can be related to the stability of the corresponding rotating wave in the ring. As a specific example, we demonstrate how the complex bifurcation scenario of simultaneously emerging multijittering solutions can be transferred from a single oscillator with delayed pulse feedback to multijittering rotating waves in a sufficiently large ring of oscillators with instantaneous pulse coupling. Finally, we present an experimental realization of this dynamical phenomenon in a system of coupled electronic circuits of FitzHugh-Nagumo type.

  6. PF-KO system for single bunch mode operation of a storage ring

    International Nuclear Information System (INIS)

    Ohgaki, H.; Sugiyama, S.; Mikado, T.; Chiwaki, M.; Yamada, K.; Suzuki, R.; Sei, N.; Noguchi, T.; Yamazaki, T.

    1994-01-01

    A new RF-KO (RF knockout) system for the single bunch mode operation of a storage ring has been developed. The knockout signal is modulated by the sum signal of the RF acceleration frequency of the storage ring and a bunch selection signal. We do not need any special device or a timing unit with this method. We obtain a high purity of bunch structure in a short knock out time. The single bunch impurity of 0.2% has been achieved. (author)

  7. Developments in Geometric Metadata and Tools at the PDS Ring-Moon Systems Node

    Science.gov (United States)

    Showalter, M. R.; Ballard, L.; French, R. S.; Gordon, M. K.; Tiscareno, M. S.

    2018-04-01

    Object-Oriented Python/SPICE (OOPS) is an overlay on the SPICE toolkit that vastly simplifies and speeds up geometry calculations for planetary data products. This toolkit is the basis for much of the development at the PDS Ring-Moon Systems Node.

  8. Infrared cavity ring-down spectroscopy with a CW diode laser system

    NARCIS (Netherlands)

    Hemerik, M.M.; Kroesen, G.M.W.; Doebele, H.F.; Muraoka, K.

    1999-01-01

    We report on the first measurements with our CRDS setup. Although the diode laser system was out of order, we were able to test the most important parts with the use of a CO laser. The first results show a ring-down time of 1.54 ~is, which is in perfect agreement with the predicted reflectivity of

  9. A reachability test for systems over polynomial rings using Gröbner bases

    NARCIS (Netherlands)

    Habets, L.C.G.J.M.

    1992-01-01

    Conditions for the reachability of a system over a polynomial ring are well known in the literature. However, the verification of these conditions remained a difficult problem in general. Application of the Gröbner Basis method from constructive commutative algebra makes it possible to carry out

  10. Characterization and reactions of a Salix extractive with a unique ring system

    Science.gov (United States)

    Lawrence Landucci; Sally Ralph; Kolby Hirth

    2003-01-01

    An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations.

  11. Vacuum system for the Stanford-LBL storage ring (PEP)

    International Nuclear Information System (INIS)

    Bostic, D.; Cummings, U.; Dean, N.; Jeong, B.; Jurow, J.

    1975-03-01

    The vacuum system for PEP will be similar in design, construction and operation to the system currently in operation at SPEAR. There will, of course, be quantitative differences since the closed path of PEP will be 10 times longer than the SPEAR path. Some qualitative differences will also arise since the radiated synchrotron power for PEP will be about 13 times greater than for SPEAR giving rise to an increased linear power density incident on the chamber wall. Other differences arise from the higher energy spectrum of the synchrotron radiation. The SPEAR vacuum system has been in operation since April 1972 and has proven satisfactory in design, construction and operation. The chamber has been subject to synchrotron radiation for approximately 300 ampere-hours and beam lifetimes are now more than several hours. The details of the PEP design and the SPEAR operating experience will be further discussed in this paper. 1 ref., 4 figs

  12. Photometric and spectroscopic evidence for a dense ring system around Centaur Chariklo

    Science.gov (United States)

    Duffard, R.; Pinilla-Alonso, N.; Ortiz, J. L.; Alvarez-Candal, A.; Sicardy, B.; Santos-Sanz, P.; Morales, N.; Colazo, C.; Fernández-Valenzuela, E.; Braga-Ribas, F.

    2014-08-01

    Context. A stellar occultation observed on 3rd June 2013 revealed the presence of two dense and narrow rings separated by a small gap around the Centaur object (10 199) Chariklo. The composition of these rings is not known. We suspect that water ice is present in the rings, as is the case for Saturn and other rings around the giant planets. Aims: In this work, we aim to determine if the variability in the absolute magnitude of Chariklo and the temporal variation of the spectral ice feature, even when it disappeared in 2007, can be explained by an icy ring system whose aspect angle changes with time. Methods: We explained the variations on the absolute magnitude of Chariklo and its ring by modeling the light reflected by a system as the one described above. Using X-shooter at VLT, we obtained a new reflectance spectra. We compared this new set of data with the ones available in the literature. We showed how the water ice feature is visible in 2013 in accordance with the ring configuration, which had an opening angle of nearly 34° in 2013. Finally, we also used models of light scattering to fit the visible and near-infrared spectra that shows different characteristics to obtain information on the composition of Chariklo and its rings. Results: We showed that absolute photometry of Chariklo from the literature and new photometric data that we obtained in 2013 can be explained by a ring of particles whose opening angle changes as a function of time. We used the two possible pole solutions for the ring system and found that only one of them, α = 151.30 ± 0.5, δ = 41.48 ± 0.2° (λ = 137.9 ± 0.5, β = 27.7 ± 0.2°), provides the right variation of the aspect angle with time to explain the photometry, whereas the other possible pole solution fails to explain the photometry. From spectral modeling, we derived the composition of the Chariklo surface and that of the rings using the result on the pole solution. Chariklo surface is composed with about 60% of amorphous

  13. Development of Low Level RF Control Systems for Superconducting Heavy Ion Linear Accelerators, Electron Synchrotrons and Storage Rings

    CERN Document Server

    Aminov, Bachtior; Kolesov, Sergej; Pekeler, Michael; Piel, Christian; Piel, Helmut

    2005-01-01

    Since 2001 ACCEL Instruments is supplying low level RF control systems together with turn key cavity systems. The early LLRF systems used the well established technology based on discrete analogue amplitude and phase detectors and modulators. Today analogue LLRF systems can make use of advanced vector demodulators and modulators combined with a fast computer controlled analogue feed back loop. Feed forward control is implemented to operate the RF cavity in an open loop mode or to compensate for predictable perturbations. The paper will introduce the general design philosophy and show how it can be adapted to different tasks as controlling a synchrotron booster nc RF system at 500 MHz, or superconducting storage ring RF cavities, as well as a linear accelerator at 176 MHz formed by a chain of individually driven and controlled superconducting λ/2 cavities.

  14. The upgraded ring loss radiation monitorinng system at the AGS

    International Nuclear Information System (INIS)

    Bennett, G.W.; Beadle, E.; Castille, V.; Witkover, R.L.

    1989-01-01

    With the Booster the AGS will accelerate protons to 3 /times/ 10 13 per cycle, polarized protons at 10 12 , and ions from Carbon to Gold at intensities from 50 to 3 /times/ 10 9 . A loss monitoring system is being developed to facilitate tuning, and to reduce personnel radiation exposure by minimizing residual induced activity and by allowing remote monitoring of activity in the accelerator enclosure. The monitoring system must have a large dynamic range to monitor high intensity beam losses and to measure induced activity down to the level of a few mrad/hour. Various detectors are being evaluated, including ion chambers, proportional counters, and aluminium cathode electronmultipliers. Measurements of the prompt ionization distribution in the median plane at various energies from point targets at two representative locations in the accelerator lattice have been completed. Details of the monitoring system will be presented, as well as the experimental measurements of the prompt radiation field, and a comparable Monte Carlo calculation. 2 refs., 5 figs

  15. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

    A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed 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 parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

  16. An innovative seismic bracing system based on a superelastic shape memory alloy ring

    International Nuclear Information System (INIS)

    Gao, Nan; Jeon, Jong-Su; DesRoches, Reginald; Hodgson, Darel E

    2016-01-01

    Shape memory alloys (SMAs) have great potential in seismic applications because of their remarkable superelasticity. Seismic bracing systems based on SMAs can mitigate the damage caused by earthquakes. The current study investigates a bracing system based on an SMA ring which is capable of both re-centering and energy dissipation. This lateral force resisting system is a cross-braced system consisting of an SMA ring and four tension-only cable assemblies, which can be applied to both new construction and seismic retrofit. The performance of this bracing system is examined through a quasi-static cyclic loading test and finite element (FE) analysis. This paper describes the experimental design in detail, discusses the experimental results, compares the performance with other bracing systems based on SMAs, and presents an Abaqus FE model calibrated on the basis of experimental results to simulate the superelastic behavior of the SMA ring. The experimental results indicate that the seismic performance of this system is promising in terms of damping and re-centering. The FE model can be used in the simulation of building structures using the proposed bracing system. (paper)

  17. In situ conditioning for proton storage ring vacuum systems

    International Nuclear Information System (INIS)

    Blechschmidt, D.

    1978-01-01

    Average pressure and vacuum-stability limit as expected in the presence of a proton beam were measured after in situ treatments such as bakeout under various conditions, argon glow-discharge cleaning and sputter deposition of titanium. Measurements were carried out for test pipes made of stainless steel (untreated, electropolished, or cooled to 77 K), pure titanium and aluminum alloy. The measurement method used to obtain the vacuum-stability limit in the laboratory and in a prototype system is described. The results can be applied also to other systems of different geometry by use of scaling laws. In situ conditioning generally has a stronger influence on vacuum performance than a particular choice of material. Bakeout gives low average pressures and rather good vacuum stability. Glow discharges also increase the vacuum stability but have only a small effect on the static pressure. Coating the beam-pipe wall with titanium by in situ sputtering provides large linear pumping, thus a lower pressure and an extremely good vacuum stability

  18. Synthesis of the ABCDEFG ring system of maitotoxin.

    Science.gov (United States)

    Nicolaou, K C; Aversa, Robert J; Jin, Jian; Rivas, Fatima

    2010-05-19

    Maitotoxin (1) continues to fascinate scientists not only because of its size and potent neurotoxicity but also due to its molecular architecture. To provide further support for its structure and facilitate fragment-based biological studies, we developed an efficient chemical synthesis of the ABCDEFG segment 3 of maitotoxin. (13)C NMR chemical shift comparisons of synthetic 3 with the corresponding values for the same carbons of maitotoxin revealed a close match, providing compelling evidence for the correctness of the originally assigned structure to this polycyclic system of the natural product. The synthetic strategy for the synthesis of 3 relied heavily on our previously developed furan-based technology involving sequential Noyori asymmetric reduction and Achmatowicz rearrangement for the construction of the required tetrahydropyran building blocks, and employed a B-alkyl Suzuki coupling and a Horner-Wadsworth-Emmons olefination to accomplish their assembly and elaboration to the final target molecule.

  19. Rf systems for high-energy e/sup /minus//e/sup /plus// storage rings

    International Nuclear Information System (INIS)

    Allen, M.A.; Wilson, P.B.

    1974-01-01

    Electron or positron beams in a storage ring radiate electromagnetic energy at a rate proportional to the fourth power of the recirculating energy, and this loss must be supplied by an rf system. Furthermore, a substantial overvoltage is required to contain the stored beam against losses due to quantum fluctuations in the emitted photons. As an example, an improvement program, SPEAR II, is now underway to increase the energy of the SPEAR ring to 4.5 GeV. At this energy, the radiation loss per turn is 2.8 MeV, and to maintain a reasonable lifetime against quantum fluctuations, a peak voltage of 7.5 MeV is required. Thus, the SPEAR II rf system is similar to a continuously-operating 7.5 MeV linear accelerator. Furthermore, the available straight-section space in the ring which is suitable for containing the accelerating structures is limited, and this means that a cavity design must be sought with a high shunt impedance per losses will be held to a reasonable level. In the case of SPEAR, about 9 meters of straight section space is available for accelerating cavities, requiring a gradient of close to 1 MV per meter. The PEP 15-GeV ring would require peak accelerating voltages of around 50 MV, with about 60 meters of straight-section space available for accelerating structures. 8 refs

  20. Active interlock system for high power insertion devices in the x-ray ring

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    In modern synchrotron radiation rings photon beams generated by high power insertion devices (IDs) may be sufficiently intense to cause severe thermal damage to the machine vacuum chamber if mis-steered. Thus when operating a storage ring with the IDs, great care must be exercised to prevent mis-steering of the electron beam orbit. At present, the X-ray ring operates with three IDs, namely two hybrid wigglers (HBW) at X-21 and X-25,a nd a 5-Tesla superconducting wiggler at X-17. All wigglers are located in low-beta straight sections. In the straight sections. In the straight sections, beam orbit may be deflected by as much as ±8 mrad without scraping the chamber wall. For various reasons it was not possible to design the X-ray ring vacuum chamber to be safe under all possible operating conditions, however, the chamber is safe for i < 7 mA, all horizontal beam deflection angles and for vertical angles < ± 2.5 mrad. To protect the machine vacuum chamber from damage due to mis-steered beams, and interlock system has been developed and installed. This system utilizes active beam position detectors which continuously monitor beam motion in each of the ID straight sections and logic circuitry which interrupts the RF and dumps the stored beam in the case of a fault

  1. A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

    OpenAIRE

    Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

    2014-01-01

    Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is propo...

  2. Ring Theory

    CERN Document Server

    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.

  3. Design of the Injection and extraction system and related machine protection for the Clic Damping Rings

    CERN Document Server

    Apsimon, Robert; Barnes, Mike; Borburgh, Jan; Goddard, Brennan; Papaphilippou, Yannis; Uythoven, Jan

    2014-01-01

    Linear machines such as CLIC have relatively low rates of collision between bunches compared to their circular counterparts. In order to achieve the required luminosity, a very small spot size is envisaged at the interaction point, thus a low emittance beam is needed. Damping rings are essential for producing the low emittances needed for the CLIC main beam. It is crucial that the beams are injected and extracted from the damping rings in a stable and repeatable fashion to minimise emittance blow-up and beam jitter at the interaction point; both of these effects will deteriorate the luminosity at the interaction point. In this paper, the parameters and constraints of the injection and extraction systems are considered and the design of these systems is optimised within this parameter space. Related machine protection is considered in order to prevent damage from potential failure modes of the injection and extraction systems.

  4. A new systematic calibration method of ring laser gyroscope inertial navigation system

    Science.gov (United States)

    Wei, Guo; Gao, Chunfeng; Wang, Qi; Wang, Qun; Xiong, Zhenyu; Long, Xingwu

    2016-10-01

    Inertial navigation system has been the core component of both military and civil navigation systems. Before the INS is put into application, it is supposed to be calibrated in the laboratory in order to compensate repeatability error caused by manufacturing. Discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed theories of error inspiration and separation in detail and presented a new systematic calibration method for ring laser gyroscope inertial navigation system. Error models and equations of calibrated Inertial Measurement Unit are given. Then proper rotation arrangement orders are depicted in order to establish the linear relationships between the change of velocity errors and calibrated parameter errors. Experiments have been set up to compare the systematic errors calculated by filtering calibration result with those obtained by discrete calibration result. The largest position error and velocity error of filtering calibration result are only 0.18 miles and 0.26m/s compared with 2 miles and 1.46m/s of discrete calibration result. These results have validated the new systematic calibration method and proved its importance for optimal design and accuracy improvement of calibration of mechanically dithered ring laser gyroscope inertial navigation system.

  5. Electronic de-multipliers II (ring-shape systems); Demultiplieurs electroniques II (systeme en anneau)

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V

    1948-09-01

    This report describes a new type of ring-shape fast electronic counter (de-multiplier) with a resolution capacity equivalent to the one made by Regener (Rev. of Scientific Instruments USA 1946, 17, 180-89) but requiring two-times less electronic valves. This report follows the general description of electronic de-multipliers made by J. Ailloud (CEA--001). The ring comprises 5 flip-flop circuits with two valves each. The different elements of the ring are calculated with enough details to allow the transfer of this calculation to different valve types. (J.S.)

  6. Rings in drugs.

    Science.gov (United States)

    Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

    2014-07-24

    We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

  7. Cyclopeptide alkaloids. Synthesis of the ring system and its ion affinity

    International Nuclear Information System (INIS)

    Lagarias, J.C.; Houghten, R.A.; Rapoport, H.

    1978-01-01

    Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li + ) and divalent (Ca 2+ , Mg 2+ ) cations. 4 figures, 1 table

  8. Efficient Test Application for Core-Based Systems Using Twisted-Ring Counters

    OpenAIRE

    Anshuman Chandra; Krishnendu Chakrabarty; Mark C. Hansen

    2001-01-01

    We present novel test set encoding and pattern decompression methods for core-based systems. These are based on the use of twisted-ring counters and offer a number of important advantages–significant test compression (over 10X in many cases), less tester memory and reduced testing time, the ability to use a slow tester without compromising test quality or testing time, and no performance degradation for the core under test. Surprisingly, the encoded test sets obtained from partially-specified...

  9. Overall design concepts for the APS storage ring machine protection system

    International Nuclear Information System (INIS)

    Lumpkin, A.; Fuja, R.; Votaw, A.; Wang, X.; Shu, D.; Stepp, J.; Arnold, N.; Nawrocki, G.; Decker, G.; Chung, Y.

    1995-01-01

    The basic design and status of the machine protection system for the Advanced Photon Source (APS) storage ring are discussed. The machine is passively safe to the bending magnet sources, but the high power of the insertion devices requires missteering conditions to be identified and the beam aborted in less than one millisecond. The basic aspects of waterflow, temperature, beam position, etc. monitoring are addressed. Initial commissioning of subsystems and sensors is statused

  10. Towards the first generation micro bulk forming system

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Eriksen, Rasmus Solmer; Hansen, Hans Nørgaard

    2011-01-01

    . This work describes a number of prototype system units, which collectively form a desktop sized micro forming production system. The system includes a billet preparation module, an integrated transfer system, a temperature controlled forming tool, including process simulation, and a dedicated micro forming......The industrial demand for micro mechanical components has surged in the later years with the constant introduction of more integrated products. The micro bulk forming process holds a promising pledge of delivering high quality micro mechanical components at low cost and high production rates...... press. The system is demonstrated on an advanced micro forming case where a dental component is formed in medical grade Titanium....

  11. Linear and nonlinear optical susceptibilities in a laterally coupled quantum-dot–quantum-ring system

    International Nuclear Information System (INIS)

    Zeng, Zaiping; Garoufalis, Christos S.; Baskoutas, Sotirios

    2014-01-01

    Linear and nonlinear optical susceptibilities in a laterally coupled quantum-dot–quantum-ring system have been theoretically studied. In general, we find that the structure parameters of the coupled system significantly affect the optical susceptibilities. The enhancement of the coupling effects between the dot and ring is found to increase considerably the optical susceptibilities and redshift drastically the transition energies. Comparing to the linear susceptibility, the nonlinear optical susceptibility is found to be more sensitive to the variation of the structure parameters. A comprehensive analysis of the electron probability density movement with respect to the modification of the structure parameters is provided, which offers a unique perspective of the ground-state localization. - Highlights: • Optical susceptibilities in a quantum-dot–quantum-ring system are studied. • The structure parameters significantly affect the optical susceptibilities. • The enhancement of the coupling effects increases the optical susceptibilities. • The nonlinear susceptibility is more sensitive to the change in structure parameters. • A comprehensive analysis of the electron probability density movement is provided

  12. An Ionosphere/Magnetosphere Coupling Current System Located in the Gap Between Saturn and its Rings

    Science.gov (United States)

    Khurana, K. K.; Dougherty, M. K.; Cao, H.; Hunt, G. J.; Provan, G.

    2017-12-01

    The Grand Finale Orbits of the Cassini spacecraft traversed through Saturn's D ring and brought the spacecraft to within 3000 km of Saturn's cloud tops. The closest approaches (CA) were near the equatorial plane of Saturn and were distributed narrowly around the local noon. The difference field (observations - internal field - magnetospheric ring current field) obtained from the Grand Finale orbits show persistent residual fields centered around the CA which diminish at higher latitudes on field lines that connect to the ring. Modeling of this perturbation in terms of internal harmonics shows that the perturbation is not of internal origin but is produced by external currents that couple the ionosphere to the magnetosphere. The sense of the current system suggests that the southern feet of the field lines in the ionosphere lead their northern footprints. We show that the observed field perturbations are consistent with a meridional Pedersen current whose strength is 1 MA/radian, i.e. comparable in strength to the Planetary-period-oscillation related current systems observed in the auroral zone. We show that the implied Lorentz force in the ionosphere extracts momentum from the faster moving southern ionosphere and passes it on to the northern ionosphere. We discuss several ideas for generating this current system. In particular, we highlight a mechanism that involves shears in the neutral winds in the thermospheric region to generate the observed magnetic field.

  13. Fractional conductance oscillations in quantum rings: wave packet picture of transport in a few-electron system

    International Nuclear Information System (INIS)

    Chwiej, T; Szafran, B

    2013-01-01

    We study electron transfer across a two-terminal quantum ring using a time-dependent description of the scattering process. For the considered scattering event the quantum ring is initially charged with one or two electrons, with another electron incident to the ring from the input channel. We study the electron transfer probability (T) as a function of the external magnetic field. We determine the periodicity of T for a varied number of electrons confined within the ring. For that purpose we develop a method to describe the wave packet dynamics for a few electrons participating in the scattering process, taking into full account the electron–electron correlations. We find that electron transfer across the quantum ring initially charged by a single electron acquires a distinct periodicity of half of the magnetic flux quantum (Φ 0 /2), corresponding to the formation of a transient two-electron state inside the ring. In the case of a three-electron scattering problem with two electrons initially occupying the ring, a period of Φ 0 /3 for T is formed in the limit of thin channels. The effect of disorder present in the confinement potential of the ring is also discussed. (paper)

  14. Fractional conductance oscillations in quantum rings: wave packet picture of transport in a few-electron system.

    Science.gov (United States)

    Chwiej, T; Szafran, B

    2013-04-17

    We study electron transfer across a two-terminal quantum ring using a time-dependent description of the scattering process. For the considered scattering event the quantum ring is initially charged with one or two electrons, with another electron incident to the ring from the input channel. We study the electron transfer probability (T) as a function of the external magnetic field. We determine the periodicity of T for a varied number of electrons confined within the ring. For that purpose we develop a method to describe the wave packet dynamics for a few electrons participating in the scattering process, taking into full account the electron-electron correlations. We find that electron transfer across the quantum ring initially charged by a single electron acquires a distinct periodicity of half of the magnetic flux quantum (Φ0/2), corresponding to the formation of a transient two-electron state inside the ring. In the case of a three-electron scattering problem with two electrons initially occupying the ring, a period of Φ0/3 for T is formed in the limit of thin channels. The effect of disorder present in the confinement potential of the ring is also discussed.

  15. Digital closed orbit feedback system for the advanced photon source storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Barr, D.; Decker, G.

    1995-01-01

    The Advanced Photon Source (APS) is a dedicated third-generation synchrotron light source with a nominal energy of 7 GeV and a circumference of 1104 m. The closed orbit feedback system for the APS storage ring employs unified global and local feedback systems for stabilization of particle and photon beams based on digital signal processing (DSP). Hardware and software aspects of the system will be described in this paper. In particular, we will discuss global and local orbit feedback algorithms, PID (proportional, integral, and derivative) control algorithm, application of digital signal processing to compensate for vacuum chamber eddy current effects, resolution of the interaction between global and local systems through decoupling, self-correction of the local bump closure error, user interface through the APS control system, and system performance in the frequency and time domains. The system hardware including the DSPs is distributed in 20 VME crates around the ring, and the entire feedback system runs synchronously at 4-kHz sampling frequency in order to achieve a correction bandwidth exceeding 100 Hz. The required data sharing between the global and local feedback systems is facilitated via the use of fiber-optically-networked reflective memories

  16. Monitor and control systems for the SLD Cherenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Boston Univ., MA; California Univ., Santa Barbara, CA; California Univ., Santa Cruz, CA; Cincinnati Univ., OH; Rutgers--the State Univ., Piscataway, NJ; Tohoku Univ., Sendai

    1989-10-01

    To help ensure the stable long-term operation of a Cherenkov Ring Detector at high efficiency, a comprehensive monitor and control system is being developed. This system will continuously monitor and maintain the correct operating temperatures, and will provide an on-line monitor and maintain the correct operating temperatures, and will provide an on-line monitor of the pressures, flows, mixing, and purity of the various fluids. In addition the velocities and trajectories of Cherenkov photoelectrons drifting within the imaging chambers will be measured using a pulsed uv lamp and a fiberoptic light injection system. 9 refs., 6 figs

  17. An active feedback system to control synchrotron oscillations in the SLC Damping Rings

    International Nuclear Information System (INIS)

    Corredoura, P.L.; Pellegrin, J.L.; Schwarz, H.D.; Sheppard, J.C.

    1989-03-01

    Initially the SLC Damping Rings accomplished Robinson instability damping by operating the RF accelerating cavities slightly detuned. In order to be able to run the cavities tuned and achieve damping for Robinson instability and synchrotron oscillations at injection an active feedback system has been developed. This paper describes the theoretical basis for the feedback system and the development of the hardware. Extensive measurements of the loop response including stored beam were performed. Overall performance of the system is also reported. 3 refs., 6 figs

  18. Conditioning of the vacuum system of the TPS storage ring without baking in situ

    Energy Technology Data Exchange (ETDEWEB)

    Chan, C.K., E-mail: ckchan@nsrrc.org.tw; Chang, C.C.; Shueh, C.; Yang, I.C.; Wu, L.H.; Chen, B.Y.; Cheng, C.M.; Huang, Y.T.; Chuang, J.Y.; Cheng, Y.T.; Hsiao, Y.M.; Sheng, Albert

    2017-04-11

    To shorten the machine downtime, a maintenance procedure without baking in situ has been developed and applied to maintain and to upgrade the vacuum system of the TPS storage ring. The data of photon-stimulated desorption (PSD) reveal no obvious discrepancy between baking and not baking the vacuum system in situ. A beam-conditioning dose of extent only 11.8 A h is required to recover quickly the dynamic pressure of an unbaked vacuum system to its pre-intervention value according to the TPS maintenance experience.

  19. Conditioning of the vacuum system of the TPS storage ring without baking in situ

    Science.gov (United States)

    Chan, C. K.; Chang, C. C.; Shueh, C.; Yang, I. C.; Wu, L. H.; Chen, B. Y.; Cheng, C. M.; Huang, Y. T.; Chuang, J. Y.; Cheng, Y. T.; Hsiao, Y. M.; Sheng, Albert

    2017-04-01

    To shorten the machine downtime, a maintenance procedure without baking in situ has been developed and applied to maintain and to upgrade the vacuum system of the TPS storage ring. The data of photon-stimulated desorption (PSD) reveal no obvious discrepancy between baking and not baking the vacuum system in situ. A beam-conditioning dose of extent only 11.8 A h is required to recover quickly the dynamic pressure of an unbaked vacuum system to its pre-intervention value according to the TPS maintenance experience.

  20. Conditioning of the vacuum system of the TPS storage ring without baking in situ

    International Nuclear Information System (INIS)

    Chan, C.K.; Chang, C.C.; Shueh, C.; Yang, I.C.; Wu, L.H.; Chen, B.Y.; Cheng, C.M.; Huang, Y.T.; Chuang, J.Y.; Cheng, Y.T.; Hsiao, Y.M.; Sheng, Albert

    2017-01-01

    To shorten the machine downtime, a maintenance procedure without baking in situ has been developed and applied to maintain and to upgrade the vacuum system of the TPS storage ring. The data of photon-stimulated desorption (PSD) reveal no obvious discrepancy between baking and not baking the vacuum system in situ. A beam-conditioning dose of extent only 11.8 A h is required to recover quickly the dynamic pressure of an unbaked vacuum system to its pre-intervention value according to the TPS maintenance experience.

  1. Magnet power supply system for the ALS storage ring and booster

    International Nuclear Information System (INIS)

    Jackson, L.T.; Luchini, K.; Lutz, I.

    1993-05-01

    The Magnet Power Supply System is described by specification, design, hardware, and operating experience. A unique system for the one Hz, 1.5 GeV Booster, where the wideband QF and QD power supplies track the dipole current to within 0.1% at injection will be detailed. AC distribution system considerations related to inverting the stored energy of the booster magnet back into power grid will be discussed. The rational for linear correctors and individual quad supplies (225 total units) will be placed within the context of the storage-ring requirements

  2. Comparison of cold and warm vacuum systems for intersecting storage rings

    International Nuclear Information System (INIS)

    Halama, H.J.; Herrera, J.C.

    1975-01-01

    In storage rings employing superconducting magnets, the use of a cold bore as a cryopump appears, at first glance, as simple and economical. Since the selection of a cold or warm vacuum system has far-reaching implications on the basic design, each system is considered in some detail. The theoretical and practical limitations imposed on the maximum beam current by the gas desorption from the chamber walls are discussed. A realistic design of a cold vacuum chamber is developed and then compared with the proposed warm ISABELLE vacuum system. The comparison shows that the warm approach is preferable. (U.S.)

  3. Stable optical soliton in the ring-cavity fiber system with carbon nanotube as saturable absorber

    Science.gov (United States)

    Li, Bang-Qing; Ma, Yu-Lan; Yang, Tie-Mei

    2018-01-01

    Main attention focuses on the theoretical study of the ring-cavity fiber laser system with carbon nanotubes (CNT) as saturable absorber (SA). The system is modelled as a non-standard Schrödinger equation with the coefficients blended real and imaginary numbers. New stable exact soliton solution is constructed by the bilinear transformation method for the system. The influences of the key parameters related to CNTs and SA on the optical pulse soliton are discussed in simulation. The soliton amplitude and phase can be tuned by choosing suitable parameters.

  4. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

  5. James Webb Space Telescope Observations of Stellar Occultations by Solar System Bodies and Rings

    Science.gov (United States)

    Santos-Sanz, P.; French, R. G.; Pinilla-Alonso, N.; Stansberry, J.; Lin, Z-Y.; Zhang, Z-W.; Vilenius, E.; Mueller, Th.; Ortiz, J. L.; Braga-Ribas, F.; hide

    2016-01-01

    In this paper, we investigate the opportunities provided by the James Webb Space Telescope (JWST) for significant scientific advances in the study of Solar System bodies and rings using stellar occultations. The strengths and weaknesses of the stellar occultation technique are evaluated in light of JWST's unique capabilities. We identify several possible JWST occultation events by minor bodies and rings and evaluate their potential scientific value. These predictions depend critically on accurate a priori knowledge of the orbit of JWST near the Sun–Earth Lagrange point 2 (L2). We also explore the possibility of serendipitous stellar occultations by very small minor bodies as a byproduct of other JWST observing programs. Finally, to optimize the potential scientific return of stellar occultation observations, we identify several characteristics of JWST's orbit and instrumentation that should be taken into account during JWST's development.

  6. Alignment of Duke free electron laser storage ring and optical beam delivery system

    International Nuclear Information System (INIS)

    Emamian, M.; Hower, N.

    1999-01-01

    Duke Free Electron Laser Laboratory (DFELL) hosts a 1.1 GeV electron beam storage ring facility which is capable of generating beams in the range of nearly monochromatic gamma rays to high peak power infra red (IR) laser. In this report specifications and procedures for alignment of OK-4 /Duke storage ring FEL wiggler and optical cavity mirrors will be discussed. The OK-4 FEL lasing has demonstrated a series of world record in the last few years. In August of this year the OK-4 FEL successfully commissioned to laser at 193.7 nm. Also in this article, alignment of the γ-ray and UV optical beam delivery system that is currently in progress will be described. (authors)

  7. Lowland river systems - processes, form and function

    DEFF Research Database (Denmark)

    Pedersen, M. L.; Kronvang, B.; Sand-Jensen, K.

    2006-01-01

    Present day river valleys and rivers are not as dynamic and variable as they used to be. We will here describe the development and characteristics of rivers and their valleys and explain the background to the physical changes in river networks and channel forms from spring to the sea. We seek...... to answer two fundamental questions: How has anthropogenic disturbance of rivers changed the fundamental form and physical processes in river valleys? Can we use our understanding of fl uvial patterns to restore the dynamic nature of channelised rivers and drained fl oodplains in river valleys?...

  8. Digital closed orbit feedback system for the Advanced Photon Source storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Barr, D.; Decker, G.; Galayda, J.; Lenkszus, F.; Lumpkin, A.; Votaw, A.J.

    1995-01-01

    Closed orbit feedback for the Advanced Photon Source (APS) storage ring employs unified global an local feedback systems for stabilization of particle and photon beams based on digital signal processing (DSP). Hardware and software aspects of the system will be described. In particular, we will discuss global and local orbit feedback algorithms, PID (proportional, integral, and derivative) control algorithm. application of digital signal processing to compensate for vacuum chamber eddy current effects, resolution of the interaction between global and local systems through decoupling, self-correction of the local bump closure error, user interface through the APS control system, and system performance in the frequency and time domains. The system hardware, including the DSPS, is distributed in 20 VNE crates around the ring, and the entire feedback system runs synchronously at 4-kHz sampling frequency in order to achieve a correction bandwidth exceeding 100 Hz. The required data sharing between the global and local feedback systems is facilitated via the use of fiber-optically-networked reflective memories

  9. Design considerations for a digital feedback system to control self-bunching in ion-storage rings

    Directory of Open Access Journals (Sweden)

    V. Ziemann

    2001-04-01

    Full Text Available We discuss the feasibility of a digital feedback system to cure self-bunching of the electron-cooled coasting ion beam in ion-storage rings such as CELSIUS [S. Holm, A. Johansson, S. Kullander, and D. Reistad, Phys. Scr. 34, 513–532 (1986]. Such a system is based on a fast digital filter that acts as a tunable artificial wake potential. It may also aid stable operation of accumulator rings for future spallation neutron sources or heavy ion rings used for inertial fusion energy production.

  10. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va'vra, J.; Williams, S.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.; Whitaker, J.S.; Wilson, R.J.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Witherell, M.; Yellin, S.; D'Oliveira, A.; Johnson, R.A.; Martinez, J.L.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Stockdale, I.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1991-02-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. We report on tests of these, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating system and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, we report on the UV transmission of recirculated liquid C 6 F 14 and on the effects of CRID construction materials on electron lifetime. 9 refs., 11 figs

  11. Development of RF-linac and storage ring system for high-current experiments at GSI

    International Nuclear Information System (INIS)

    Hofmann, I.

    1986-08-01

    The heavy ion facility under construction at GSI is suitable for the generation of high-current beams. It consists of a new high-current injector into the Unilac and a synchrotron and storage ring. We discuss the capability of this system to produce short pulses of heavy ions with a specific energy of the order of 0.1 MJ/g. Under these conditions the system allows to perform a first generation of heavy ion driven target experiments and to test most of the critical issues of a large scale heavy ion fusion driver facility. (orig.)

  12. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Bird, F.; Aston, D.; Dasu, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Nagamine, T.; Pavel, T.; Muller, D.; Williams, S.; Bienz, T.; Dolinsky, S.; Solodov, E.; Coyle, P.; Cavalli-Sforza, M.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.

    1990-01-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. This paper reports on tests of these components, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating system and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, the authors report on the UV transmission of recirculated liquid freon and on the effects of CRID construction materials on electron lifetime

  13. A digital feedback system for transverse orbit stabilization in the NSLS rings

    International Nuclear Information System (INIS)

    Friedman, A.; Bozoki, E.

    1993-01-01

    We are reporting on the design and preliminary results of a prototype digital feedback system for the storage rings at the NSLS. the system will use a nolinear eigenvector decomposition algorithm. It will have a wide dynamic range and will be able to correct noise in the orbit over a bandwidth in excess of 60 Hz. A Motorola-162 CPU board is used to sample the PUE's at a minimum rate of 200 Hz and an HP-742rt board is used to read the sampled signals and to generate a correction signal for the orbit correctors

  14. Component and system tests of the SLD Cerenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dolinsky, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va'vra, J.; Williams, S.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Williams, D.A.; Whitaker, J.S.; Wilson, R.J.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Witherell, M.; Yellin, S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Meadows, B.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Stockdale, I.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H.

    1990-10-01

    The components of the SLD barrel Cerenkov Ring Imaging Detector (CRID) are now built and are being installed. We report on tests of these components, including tests of the fiber optic calibration system, detailed studies of electron drift paths on production drift boxes and detectors, tests of the dynamic gating systems and its effect on drift path distortions due to space-charge, and a measurement of the electron lifetime in a production drift box. In addition, we report on the UV transmission of recirculated liquid freon and on the effects of CRID construction materials on electron lifetime. 16 refs., 12 figs

  15. The vacuum system for the PEP II high energy ring straight sections

    International Nuclear Information System (INIS)

    Wienands, U.; Daly, E.; Heifets, S.A.; Kulikov, A.; Kurita, N.; Nordby, M.; Perkins, C.; Reuter, E.; Seeman, J.T.; Belser, F.C.; Berg, J.; Holdener, F.R.; Kerns, J.A.; McDaniel, M.R.; Stoeffl, W.

    1995-01-01

    The six straight sections of the PEP II High Energy Ring (HER) serve various functions: lattice tuning, beam injection and abort, providing space for rf cavities, longitudinal and transverse feedback, beam diagnostics and the interaction point. A stainless steel vacuum system has been designed; prototypes are currently being built. Cooling is required due to radiation coming from the last arc dipole and resistive losses in the vacuum chamber. Although the nominal beam current of the HER is 1 A the vacuum system is designed for 3 A to provide margin and an upgrade path. 5 refs., 7 figs

  16. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    1983-12-01

    The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

  17. Variable diameter CO2 laser ring-cutting system adapted to a zoom microscope for applications on polymer tapes.

    Science.gov (United States)

    Förster, Erik; Bohnert, Patrick; Kraus, Matthias; Kilper, Roland; Müller, Ute; Buchmann, Martin; Brunner, Robert

    2016-11-20

    This paper presents the conception and implementation of a variable diameter ring-cutting system for a CO2 laser with a working wavelength of 10.6 μm. The laser-cutting system is adapted to an observation zoom microscope for combined use and is applicable for the extraction of small circular areas from polymer films, such as forensic adhesive tapes in a single shot. As an important characteristic for our application, the variable diameter ring-cutting system provides telecentricity in the target area. Ring diameters are continuously tunable between 500 μm and 2 mm. A minimum width of less than 20 μm was found for the ring profile edge. The basic characteristics of the system, including telecentricity, were experimentally evaluated and demonstrated by cutting experiments on different polymer tapes and further exemplary samples.

  18. Preliminary study on the adjonction of a cooling system and internal target ring to the GEPL project

    International Nuclear Information System (INIS)

    Potaux, D.

    1983-01-01

    Various heavy particle storage rings (LEAR, Indiana, Uppsala) are planned for operation with combined electron cooling system and internal ultra-thin targets. The advantage of adding a similar device to the IPN cyclotron project is discussed [fr

  19. The terminal Eocene event - Formation of a ring system around the earth

    Science.gov (United States)

    Okeefe, J. A.

    1980-01-01

    It is suggested that the formation of a ring system about the earth by particles and debris related to the North American strewn tektite field is responsible for the terminal Eocene event of 34 million years ago, in which severe climatic changes accompanied by widespread biological extinctions occurred. Botanical data is cited which implies a 20-C decrease in winter temperature with no change in summer temperature, and evidence of the correlation of the North American tektite fall, which is estimated to have a total mass of 10 to the 9th to 10 to the 10th tons, with the disappearance of five of the most abundant species of radiolaria is presented. The possible connection between the tektites and climatic change is argued to result from the screening of sunlight by an equatorial ring of trapped particles of extraterrestrial origin in geocentric orbit which would cut off sunlight only in the winter months. Such a ring, located at a distance of between 1.5 and 2.5 earth radii (the Roche limit) is estimated to have a lifetime of a few million years.

  20. Digital Low Level RF Systems for Fermilab Main Ring and Tevatron

    Science.gov (United States)

    Chase, B.; Barnes, B.; Meisner, K.

    1997-05-01

    At Fermilab, a new Low Level RF system is successfully installed and operating in the Main Ring. Installation is proceeding for a Tevatron system. This upgrade replaces aging CAMAC/NIM components for an increase in accuracy, reliability, and flexibility. These VXI systems are based on a custom three channel direct digital synthesizer(DDS) module. Each synthesizer channel is capable of independent or ganged operation for both frequency and phase modulation. New frequency and phase values are computed at a 100kHz rate on the module's Analog Devices ADSP21062 (SHARC) digital signal processor. The DSP concurrently handles feedforward, feedback, and beam manipulations. Higher level state machines and the control system interface are handled at the crate level using the VxWorks operating system. This paper discusses the hardware, software and operational aspects of these LLRF systems.

  1. SPEED COMPLIANCE IN FREEWAY VARIABLE SPEED LIMIT SYSTEM – CASE STUDY OF THE PRAGUE CITY RING

    Directory of Open Access Journals (Sweden)

    Michał MATOWICKI

    2016-03-01

    Full Text Available Many previous studies have confirmed the strong relationship between speed compliance and the frequency and severity of traffic accidents. Variable speed limit (VSL system as a measure to improve traffic safety enables the freeway system to change its posted speed limit based on various traffic and environmental conditions. Such system helps drivers to recognize the upcoming events, to adjust their driving style and in such way to address speed variation of the traffic flow. This is called speed harmonization. Although many studies researching the effect of VSL system on the traffic stream can be found, there are only few addressing its influence on the drivers behavior, particularly focusing on their tolerance limit and compliance, which has crucial meaning for future design of controlling algorithms. This study was prepared to inspect this grey area by studying the data from the VSL system at Prague city ring, describing the influence of the highway management system and its influence on drivers.

  2. A Performance Comparison of Tree and Ring Topologies in Distributed System

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    A distributed system is a collection of computers that are connected via a communication network. Distributed systems have become commonplace due to the wide availability of low-cost, high performance computers and network devices. However, the management infrastructure often does not scale well when distributed systems get very large. Some of the considerations in building a distributed system are the choice of the network topology and the method used to construct the distributed system so as to optimize the scalability and reliability of the system, lower the cost of linking nodes together and minimize the message delay in transmission, and simplify system resource management. We have developed a new distributed management system that is able to handle the dynamic increase of system size, detect and recover the unexpected failure of system services, and manage system resources. The topologies used in the system are the tree-structured network and the ring-structured network. This thesis presents the research background, system components, design, implementation, experiment results and the conclusions of our work. The thesis is organized as follows: the research background is presented in chapter 1. Chapter 2 describes the system components, including the different node types and different connection types used in the system. In chapter 3, we describe the message types and message formats in the system. We discuss the system design and implementation in chapter 4. In chapter 5, we present the test environment and results, Finally, we conclude with a summary and describe our future work in chapter 6.

  3. Free-Form Kinetic Reciprocal System

    DEFF Research Database (Denmark)

    Parigi, Dario; Sassone, Mario

    2011-01-01

    Kinetic Reciprocal System (KRS) are innovative moveable structures based on the principle of reciprocity [1] with internal pin-slot constraints [2]. The analysis of KRS kinematic and static determinacy is developed through the construction of kinematic matrices, accordingly with [3] and a discuss...

  4. Automatic local beam steering systems for NSLS x-ray storage ring: Design and implementation

    International Nuclear Information System (INIS)

    Singh, O.V.; Nawrocky, R.; Flannigan, J.

    1991-01-01

    Recently, two local automatic steering systems, controlled by microprocessors, have been installed and commissioned in the NSLS X- Ray storage ring. In each system, the position of the electron beam is stabilized at two locations by four independent servo systems. This paper describes three aspects of the local feedback program: design; commissioning; and limitation. The system design is explained by identifying major elements such as beam position detectors, signal processors, compensation amplifiers, ratio amplifiers, trim equalizers and microprocessor feedback controllers. System commissioning involves steps such as matching trim compensation, determination of local orbit bumps, measurement of open loop responses and design of servo circuits. Several limitations of performance are also discussed. 7 refs., 2 figs

  5. New beam-position monitor system for upgraded Photon Factory storage ring.

    Science.gov (United States)

    Haga, K; Honda, T; Tadano, M; Obina, T; Kasuga, T

    1998-05-01

    Accompanying the brilliance-upgrading project at the Photon Factory storage ring, the beam-position monitor (BPM) system has been renovated. The new system was designed to enable precise and fast measurements to correct the closed-orbit distortion (COD), as well as to feed back the orbit position during user runs. There are 42 BPMs newly installed, amounting to a total of 65 BPMs. All of the BPMs are calibrated on the test bench using a coaxially strung metallic wire. The measured electrical offsets are typically 200 micro m in both directions, which is 1/2-1/3 of those of the old-type BPMs. In the signal-processing system, PIN diode switches are employed in order to improve reliability. In the fastest mode, this system is capable of measuring COD within about 10 ms; this fast acquisition will allow fast suppression of the beam movement for frequencies up to 50 Hz using a global feedback system.

  6. LOCATING THE TRAILING EDGE OF THE CIRCUMBINARY RING IN THE KH 15D SYSTEM

    International Nuclear Information System (INIS)

    Capelo, Holly L.; Herbst, William; Leggett, S. K.; Hamilton, Catrina M.; Johnson, John A.

    2012-01-01

    Following two years of complete occultation of both stars in the binary T Tauri star KH 15D by its opaque circumbinary ring, KH 15D has abruptly brightened again during apastron phases, reaching I = 15 mag. Here, we show that the brightening is accompanied by a change in spectral class from K6/K7 (the spectral class of star A) to ∼K1, and a bluing of the system in V – I by about 0.3 mag. A radial velocity measurement confirms that, at apastron, we are now seeing direct light from star B, which is more luminous and of earlier spectral class than star A. Evidently, the trailing edge of the occulting screen has just become tangent to one anse of star B's projected orbit. This confirms a prediction of the precession models, supports the view that the tilted ring is self-gravitating, and ushers in a new era of the system's evolution that should be accompanied by the same kind of dramatic phenomena observed from 1995 to 2009. It also promotes KH 15D from a single-lined to a double-lined eclipsing binary, greatly enhancing its value for testing pre-main-sequence models. The results of our study strengthen the case for truncation of the outer ring at around 4 AU by a sub-stellar object such as an extremely young giant planet. The system is currently at an optimal configuration for detecting the putative planet and we urge expedient follow-up observations.

  7. Simulation of a transverse feedback system for the SSRF storage ring

    International Nuclear Information System (INIS)

    Jiang Bocheng; Chinese Academy of Sciences, Beijing; Liu Guimin; Zhao Zhentang

    2007-01-01

    Resistive wall instability is a serious problem in many light sources. An active transverse feedback system (TFS) is required to operate the machine in a good condition when beam current is high. In order to investigate beam dynamics with TFS turned on, we developed a TFS simulation program. The feedback effectiveness for the Shanghai Synchrotron Radiation Facility (SSRF) storage ring is simulated under various conditions such as closed orbit distortion included, beam position monitor reading errors added, and finite-duration impulse-response filter strategy changed. (authors)

  8. Detector system for e-d scattering experiments on the VEPP-3 storage ring

    International Nuclear Information System (INIS)

    Isaeva, L.G.; Lazarenko, B.A.; Nikolenko, D.M.; Popov, S.G.; Rachek, I.A.; Ukraintsev, Yu.G.; Tsentalovich, E.P.; Wojtsekhowski, B.B.; Nelubin, V.V.

    1993-01-01

    Experiments on electron scattering from polarized deuterons were carried out on the VEPP-3 storage ring at the Novosibirsk Institute for Nuclear Physics. The e-D coincidences were detected for elastic scattering experiments, and the p-n coincidences for photo disintegration studies. The tensor analyzing power of the elastic scattering was measured in the range of momentum transfer up to 3 f -1 , and of photo disintegration in the range of photon energy up to 500 MeV. The detector system created for these experiments and the data analysis procedures are described in this paper. (orig.)

  9. Optical Properties of a Quantum Dot-Ring System Grown Using Droplet Epitaxy.

    Science.gov (United States)

    Linares-García, Gabriel; Meza-Montes, Lilia; Stinaff, Eric; Alsolamy, S M; Ware, M E; Mazur, Y I; Wang, Z M; Lee, Jihoon; Salamo, G J

    2016-12-01

    Electronic and optical properties of InAs/GaAs nanostructures grown by the droplet epitaxy method are studied. Carrier states were determined by k · p theory including effects of strain and In gradient concentration for a model geometry. Wavefunctions are highly localized in the dots. Coulomb and exchange interactions are studied and we found the system is in the strong confinement regime. Microphotoluminescence spectra and lifetimes were calculated and compared with measurements performed on a set of quantum rings in a single sample. Some features of spectra are in good agreement.

  10. Vacuum system design for the PEP-II B Factory High-Energy Ring

    International Nuclear Information System (INIS)

    Perkins, C.; Bostic, D.; Daly, E.

    1994-06-01

    The design of the vacuum system for the PEP-II B Factory High-Energy Ring is reviewed. The thermal design and vacuum requirements are particularly challenging in PEP-II due to high stored beam currents up to 3.0 amps in 1658 bunches. The vacuum chambers for the HER arcs are fabricated by electron beam welding extruded copper sections up to 6 m long. Design of these chambers and the vacuum PumPing configuration is described with results from vacuum and thermal analyses

  11. The amplitude and phase control of the ALS Storage Ring RF System

    International Nuclear Information System (INIS)

    Lo, C.C.; Taylor, B.; Baptiste, K.

    1995-03-01

    A 500MHz, 300KW Klystron power amplifier provides RF power to the ALS Storage Ring. In order to accommodate the amplitude and phase changes during beam stacking and decay, which demand continuously varying power levels from the Klystron, four loops are used to keep the system operating properly, with two of those loops dedicated to keeping the two cavity tuners on tune. Description of the control loops and their performance data will be given. Using the modulation anode of the Klystron in the amplitude loop will be discussed

  12. Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study.

    Science.gov (United States)

    Kalavathi, M; Sachin, Bhuvana; Prasanna, B G; Shreeharsha, T V; Praveen, B; Ragher, Mallikarjuna

    2016-02-01

    The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless casting technique and the conventional technique using the metal rings were compared. A total of 30 wax patterns were fabricated directly on a metal die. Optical stereomicroscope was used to measure the marginal discrepancy between the metal die and wax patterns. A total of 15 castings were invested using Bellavest T phosphate-bonded investment with the ringless technique and 15 were invested with the same investment with a metal ring; 30 castings were produced using a nickel-chromium ceramo-metal alloy. The internal surface of the castings was not modified and seated with finger pressure. The vertical marginal discrepancy was measured using an optical stereomicroscope at a magnification of 100x. The data obtained were statistically analyzed using students t-test (paired t-test and unpaired t-test). The castings of the ringless technique provided less vertical marginal discrepancy (240.56 ± 45.81 μ) than the castings produced with the conventional metal ring technique (281.98± 53.05 μ). The difference was statistically significant. The ringless casting technique had produced better marginal accuracy compared with conventional casting technique. Ringless casting system can be used routinely for clinical purpose.

  13. Experience with the New Digital RF Control System at the CESR Storage Ring

    CERN Document Server

    Liepe, Matthias; Dobbins, John; Kaplan, Roger; Strohman, Charles R; Stuhl, Benjamin K

    2005-01-01

    A new digital control system has been developed, providing great flexibility, high computational power and low latency for a wide range of control and data acquisition applications. This system is now installed in the CESR storage ring and stabilizes the vector sum field of two of the superconducting CESR 500 MHz cavities and the output power from the driving klystron. The installed control system includes in-house developed digital and RF hardware, very fast feedback and feedforward control, a state machine for automatic start-up and trip recovery, cw and pulsed mode operation, fast quench detection, and cavity frequency control. Several months of continuous operation have proven high reliability of the system. The achieved field stability surpasses requirements.

  14. Introduction to the magnet and vacuum systems of an electron storage ring

    International Nuclear Information System (INIS)

    Weng, W.T.

    1982-01-01

    An accelerator or storage ring complex is a concerted interplay of various functional systems. For the convenience of discussion we can divide it into the following systems: injector, magnet, RF, vacuum, instrumentation and control. In addition, the conventional construction of the building and radiation safety consideration are also needed and finally the beam lines, detector, data acquisition and analysis set-ups for research programs. Dr. L. Teng has given a comprehensive review of the whole complex and the operation of such a facility. I concentrate on the description of magnet and vacuum systems. Only the general function of each system and the basic design concepts will be introduced, no detailed engineering practice will be given which will be best done after a machine design is produced. For further understanding and references a table of bibliography is provided at the end of the paper

  15. Development of a computer control system for the RCNP ring cyclotron

    International Nuclear Information System (INIS)

    Ogata, H.; Yamazaki, T.; Ando, A.; Hosono, K.; Itahashi, T.; Katayama, I.; Kibayashi, M.; Kinjo, S.; Kondo, M.; Miura, I.; Nagayama, K.; Noro, T.; Saito, T.; Shimizu, A.; Uraki, M.; Maruyama, M.; Aoki, K.; Yamada, S.; Kodaira, K.

    1990-01-01

    A hierarchically distributed computer control system for the RCNP ring cyclotron is being developed. The control system consists of a central computer and four subcomputers which are linked together by an Ethernet, universal device controllers which control component devices, man-machine interfaces including an operator console and interlock systems. The universal device controller is a standard single-board computer with an 8344 microcontroller and parallel interfaces, and is usually integrated into a component device and connected to a subcomputer by means of an optical-fiber cable to achieve high-speed data transfer. Control sequences for subsystems are easily produced and improved by using an interpreter language named OPELA (OPEration Language for Accelerators). The control system will be installed in March 1990. (orig.)

  16. Cavity ring-down spectroscopy (CRDS) system for measuring atmospheric mercury using differential absorption

    Science.gov (United States)

    Pierce, A.; Obrist, D.; Moosmuller, H.; Moore, C.

    2012-04-01

    Atmospheric elemental mercury (Hg0) is a globally pervasive element that can be transported and deposited to remote ecosystems where it poses — particularly in its methylated form — harm to many organisms including humans. Current techniques for measurement of atmospheric Hg0 require several liters of sample air and several minutes for each analysis. Fast-response (i.e., 1 second or faster) measurements would improve our ability to understand and track chemical cycling of mercury in the atmosphere, including high frequency Hg0 fluctuations, sources and sinks, and chemical transformation processes. We present theory, design, challenges, and current results of our new prototype sensor based on cavity ring-down spectroscopy (CRDS) for fast-response measurement of Hg0 mass concentrations. CRDS is a direct absorption technique that implements path-lengths of multiple kilometers in a compact absorption cell using high-reflectivity mirrors, thereby improving sensitivity and reducing sample volume compared to conventional absorption spectroscopy. Our sensor includes a frequency-doubled, dye-laser emitting laser pulses tunable from 215 to 280 nm, pumped by a Q-switched, frequency tripled Nd:YAG laser with a pulse repetition rate of 50 Hz. We present how we successfully perform automated wavelength locking and stabilization of the laser to the peak Hg0 absorption line at 253.65 nm using an external isotopically-enriched mercury (202Hg0) cell. An emphasis of this presentation will be on the implementation of differential absorption measurement whereby measurements are alternated between the peak Hg0 absorption wavelength and a nearby wavelength "off" the absorption line. This can be achieved using a piezo electric tuning element that allows for pulse-by-pulse tuning and detuning of the laser "online" and "offline" of the Hg absorption line, and thereby allows for continuous correction of baseline extinction losses. Unexpected challenges with this approach included

  17. The New Horizons and Hubble Space Telescope search for rings, dust, and debris in the Pluto-Charon system

    Science.gov (United States)

    Lauer, Tod R.; Throop, Henry B.; Showalter, Mark R.; Weaver, Harold A.; Stern, S. Alan; Spencer, John R.; Buie, Marc W.; Hamilton, Douglas P.; Porter, Simon B.; Verbiscer, Anne J.; Young, Leslie A.; Olkin, Cathy B.; Ennico, Kimberly; New Horizons Science Team

    2018-02-01

    We conducted an extensive search for dust or debris rings in the Pluto-Charon system before, during, and after the New Horizons encounter in July 2015. Methodologies included attempting to detect features by back-scattered light during the approach to Pluto (phase angle α ∼ 15°), in situ detection of impacting particles, a search for stellar occultations near the time of closest approach, and by forward-scattered light imaging during departure (α ∼ 165°). An extensive search using the Hubble Space Telescope (HST) prior to the encounter also contributed to the final ring limits. No rings, debris, or dust features were observed, but our new detection limits provide a substantially improved picture of the environment throughout the Pluto-Charon system. Searches for rings in back-scattered light covered the range 35,000-250,000 km from the system barycenter, a zone that starts interior to the orbit of Styx, the innermost minor satellite, and extends out to four times the orbital radius of Hydra, the outermost known satellite. We obtained our firmest limits using data from the New Horizons LORRI camera in the inner half of this region. Our limits on the normal I/F of an unseen ring depends on the radial scale of the rings: 2 ×10-8 (3σ) for 1500 km wide rings, 1 ×10-8 for 6000 km rings, and 7 ×10-9 for 12,000 km rings. Beyond ∼ 100, 000 km from Pluto, HST observations limit normal I/F to ∼ 8 ×10-8 . Searches for dust features from forward-scattered light extended from the surface of Pluto to the Pluto-Charon Hill sphere (rHill = 6.4 ×106 km). No evidence for rings or dust clouds was detected to normal I/F limits of ∼ 8.9 ×10-7 on ∼ 104 km scales. Four stellar occulation observations also probed the space interior to Hydra, but again no dust or debris was detected. The Student Dust Counter detected one particle impact 3.6 × 106 km from Pluto, but this is consistent with the interplanetary space environment established during the cruise of New

  18. Characterizing exo-ring systems around fast-rotating stars using the Rossiter-McLaughlin effect

    Science.gov (United States)

    de Mooij, Ernst J. W.; Watson, Christopher A.; Kenworthy, Matthew A.

    2017-12-01

    Planetary rings produce a distinct shape distortion in transit light curves. However, to accurately model such light curves the observations need to cover the entire transit, especially ingress and egress, as well as an out-of-transit baseline. Such observations can be challenging for long period planets, where the transits may last for over a day. Planetary rings will also impact the shape of absorption lines in the stellar spectrum, as the planet and rings cover different parts of the rotating star (the Rossiter-McLaughlin effect). These line-profile distortions depend on the size, structure, opacity, obliquity and sky-projected angle of the ring system. For slow-rotating stars, this mainly impacts the amplitude of the induced velocity shift; however, for fast-rotating stars the large velocity gradient across the star allows the line distortion to be resolved, enabling direct determination of the ring parameters. We demonstrate that by modelling these distortions we can recover ring system parameters (sky-projected angle, obliquity and size) using only a small part of the transit. Substructure in the rings, e.g. gaps, can be recovered if the width of the features (δW) relative to the size of the star is similar to the intrinsic velocity resolution (set by the width of the local stellar profile, γ) relative to the stellar rotation velocity (v sini, i.e. δW/R* ≳ vsini/γ). This opens up a new way to study the ring systems around planets with long orbital periods, where observations of the full transit, covering the ingress and egress, are not always feasible.

  19. Visual search for motion-form conjunctions: is form discriminated within the motion system?

    Science.gov (United States)

    von Mühlenen, A; Müller, H J

    2001-06-01

    Motion-form conjunction search can be more efficient when the target is moving (a moving 45 degrees tilted line among moving vertical and stationary 45 degrees tilted lines) rather than stationary. This asymmetry may be due to aspects of form being discriminated within a motion system representing only moving items, whereas discrimination of stationary items relies on a static form system (J. Driver & P. McLeod, 1992). Alternatively, it may be due to search exploiting differential motion velocity and direction signals generated by the moving-target and distractor lines. To decide between these alternatives, 4 experiments systematically varied the motion-signal information conveyed by the moving target and distractors while keeping their form difference salient. Moving-target search was found to be facilitated only when differential motion-signal information was available. Thus, there is no need to assume that form is discriminated within the motion system.

  20. Vibration characteristics of two-stage planetary transmission system with thin-walled ring gear on elastic supports

    Science.gov (United States)

    Li, JianYing; Hu, QingChun; Zong, ChangFu; Zhu, TianJun; Zhang, ZeXing

    2018-03-01

    A dual-clutch and dual-speed planetary gears mechanism of a hybrid car coupled-system is taken as research subject, in which the ring gear of planet set II is a thin-walled structure and the clutch friction plates of planet set II are used as its elastic supports. Based on the lumped parameter-rigid elastic coupled dynamic model of two-stage planetary transmission system with thin-walled ring gear on elastic supports, the motion differential equations are established and the dynamic responses are solved by the Runge-Kutta method considering each stage internal and external time-varying mesh stiffness. The vibration displacements of each stage ring gear have been affected differently in time-domain, the translational vibration displacement of the ring gear of planet set I are obviously more than the torsional vibration displacement, but it is opposite for the ring gear of planet set II; The translational and torsional vibration responses of each stage ring gear arrive the peak in low-frequency. The analysis results of this paper can enrich the theoretical research of multistage planetary transmission and provide guidance for dynamic design.

  1. Mechanical loading of the gymnast’s motor system during swings on rings

    Directory of Open Access Journals (Sweden)

    R Serafin

    2008-12-01

    Full Text Available The aim of this work was to identify the mechanical loading of the gymnast’s motor system during forward and backward swings on gymnastic rings. A junior gymnast of the First Class, aged 14, with body mass 53.1 kg and body length 1.61 m, participated in the study. He executed a series of ten cyclic swing movements on rings with his maximum amplitude. Kinematic variables of the gymnast’s centre of mass (COM as well as reaction forces in the cables were measured and synchronized using the SIMI MOTION movement analysis system. Two separate phases of mechanical loading of the motor system have been identified: resistance phase and non resistance phase. In the non resistance phase the gymnast attains similar values of the COM’s momentum but different angular displacements. In the resistance phase the forces acting on the motor system have their maximum. They amount to 5.5 BW for the forward swing and 6.5 BW for the backward swing movement. The maximum rate of change of the force for forward and backward swing is 42.6 BWs-1 and 67.4 BWs-1, respectively. These two variables differentiate the mechanical loading of the gymnast’s motor system between forward and backward swings. The reaction force produced by the gymnast is significantly greater during the execution of forward swings. It seems probable that horizontal displacements of COM may be the factor responsible for reduction of the mechanical loading experienced by the gymnast.

  2. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  3. Vacuum system of the high energy ring of an asymmetric B-factory based on PEP

    International Nuclear Information System (INIS)

    Barletta, W.A.; Calderon, M.O.; Wong, R.; Jenkins, T.M.

    1991-01-01

    The multi-ampere currents required for high luminosity operation of an asymmetric B factory leads to extremely stressing requirements on a vacuum system suitable for maintaining long beam-gas lifetimes and acceptable background levels in the detector. We present the design for a Cu alloy vacuum chamber and its associated pumping system for the 9 GeV electron storage ring of the proposed B factory based on PEP. The excellent thermal and photo-desorption properties of Cu allows handling the high proton flux in a conventional, single chamber design with distributed ion pumps. The x-ray opacity of the Cu is sufficiently high that no additional lead shielding is necessary to protect the dipoles from the intense synchrotron radiation generated by the beam. The design allows chamber commissioning in <500 hr of operation. 5 refs., 3 figs., 2 tabs

  4. The control systems for the CERN Super Proton Synchrotron ring power supplies

    CERN Document Server

    Kuhn, H K

    1981-01-01

    The dedicated control system for the 16 voltage-controlled Main Ring pulsed supplies, allowing the reproduction of the desired B and Q fields to better than +or-2*10/sup -4/ at injection is described. It outlines both the hardware (smoothed function generators) and software side. Current measurements via DVMs or the B train off the reference magnets are used as inputs to the correction algorithm which is based on successive approximation. The algorithm enables the machine operators to trim selectively both the closed orbit and/or the betatron wave number of the machine within 1 to a few cycles. The control system related computer memory requirements are given. (0 refs).

  5. Reflective variable optical attenuators and fibre ring lasers for wavelength-division multiplexing systems

    Science.gov (United States)

    Liu, He Liang

    Wavelength division multiplexing (WDM) optical fibre system is an important enabling technology to fulfill the demands for bandwidth in the modern information age. The main objective of this project is to study novel devices with the potential to enhance the performance of WDM systems. In particular, a novel reflective variable optical attenuator (RVOA) used for dynamic gain equalization (DGE) and fibre lasers based on an entirely new type of erbium-doped fibres with ultrawide tuning range were investigated theoretically and experimentally. We proposed a new type of RVOA device which could be potentially integrated with arrayed waveguide grating (AWG) to reduce the cost of DGE substantially. Initially, fibre-based RVOAs, fabricated with optical fibre components such as fibre coupler and Faraday rotator mirror, were investigated theoretically and experimentally. Larger attenuation range up to 22 dB was realized for fibre coupler-based ROVA with a Faraday rotator mirror and its polarization-dependent loss is about 0.5 dB. Then polymeric waveguide-based RVOAs were investigated theoretically and experimentally. Using an epoxy Novolak resin as core material and an UV-cured resin (Norland's NOA61) as cladding material, a polymeric waveguide RVOA was successfully fabricated. The dynamic 15 dB attenuation range was achieved and the PDL was less than 0.2 dB. The measured insertion loss of the polymeric waveguide RVOA was too large (about 18 dB) and was mainly induced by coupling loss, material loss and poor alignment. In the second part of the study, fibre ring lasers with continuous wavelength tuning over wide wavelength range and fibre ring lasers with discrete wavelength tuning were investigated. Tunable lasers are important devices in WDM systems because they could be employed as reserved sources and therefore avoiding the need to stock large inventory of lasers to cover the ITU-wavelength grid. In this project, erbium ions doped bismuth oxide glass fibres instead of

  6. System of marketing: principles of forming, functioning and development

    OpenAIRE

    Mazko, T.

    2010-01-01

    Initial positions of system marketing forming, functioning and development are examined as a component subsystem to the enterprise. Principles are offered in relation to the certain states of the system of marketing for enterprise

  7. Normal form of linear systems depending on parameters

    International Nuclear Information System (INIS)

    Nguyen Huynh Phan.

    1995-12-01

    In this paper we resolve completely the problem to find normal forms of linear systems depending on parameters for the feedback action that we have studied for the special case of controllable linear systems. (author). 24 refs

  8. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . 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)

  9. Influence of system considerations on waste form design

    International Nuclear Information System (INIS)

    Bauer, A.A.; Matthews, S.C.; Peterson, R.W.

    1979-01-01

    The design of waste forms is constrained by waste management system considerations imposed during generation, treatment, packaging, transportation, storage, and isolation. In the isolation phase, the waste form provides one of the barriers to release in a multibarrier system that includes the natural geologic and hydrologic barriers as well as other engineered barriers

  10. Electromagnetic Calculation of Combined Earthing System with Ring Earth Electrode and Vertical Rods for Wind Turbine

    Science.gov (United States)

    Fujii, Toshiaki; Yasuda, Yoh; Ueda, Toshiaki

    With the worldwide spread of wind turbine installations, various problems such as landscape issues, bird strikes and grid connections have arisen. Protection of wind turbines from lightning is cited as one of the main problems. Wind turbines are often struck by lightning because of their open-air locations, such as in mountainous areas, and their special configuration and very-high construction. Especially, low-voltage and control circuits can fail or suffer burnout while blades can incur serious damage if struck by lightning. Wind turbine failures caused by lightning strikes account for approximately 25% of all failures. The problem is regarded as a global one that needs immediate resolution. It is important to understand the impedance characteristics of wind turbine earthing systems from the viewpoint of lightning protection. A report from IEC TR61400-24 recommends a “ring earth electrode”. This was originally defined in IEC 61024 (currently revised and re-numbered as IEC 62305), where such an electrode is recommended to reduce touch and step voltages in households and buildings. IEC TR61400-24 also recommended additional electrodes of vertical or horizontal rods. However, these concepts have not been fully discussed from the viewpoint of its application to wind turbines. To confirm the effect of a combination of a ring earth electrode and additional vertical rods for protection of a wind turbine, this report uses the Finite Difference Time Domain (FDTD) method to present an electromagnetic transient analysis on such a wind turbine earthing system. The results show that an optimal combination can be arranged from viewpoints of lightning protection and construction cost. Thus, this report discusses how to establish a quantitative design methodology of the wind turbine earthing system to provide effective lightning protection.

  11. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

    1998-01-05

    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  12. New data acquisition system for beam loss monitor used in J-PARC main ring

    Science.gov (United States)

    Satou, K.; Toyama, T.; Kamikubota, N.; Yoshida, S.; Matsushita, J.; Wakita, T.; Sugiyama, M.; Morino, T.

    2018-04-01

    A new data acquisition system has been developed continually as a part of the development of a new beam loss monitor (BLM) system for the J-PARC main ring. This development includes a newly designed front-end isolation amp that uses photo-couplers and a VME-based new analog-to-digital converter (ADC) system. Compared to the old amp, the new amp has a 10 times higher conversion impedance for the input current to the output voltage; this value is 1 M Ω. Moreover, the bandwidth was improved to from DC to 50 kHz, which is about two orders of magnitude greater than the previously used bandwidth. The theoretical estimations made in this study roughly agree with the frequency response obtained for the new system. The new ADC system uses an on-board field-programmable gate array chip for signal processing. By replacing the firmware of this chip, changes pertaining to future accelerator upgrade plans may be introduced into the new ADC system; in addition, the ADC system can be used in other applications. The sampling speed of the system is 1 MS/s, and it exhibits a 95 dBc spurious-free dynamic range and 16.5 effective number of bits. The obtained waveform and integrated charge data are compared with two reference levels in the ADC system. If the data exceeds the reference level, the system generates an alarm to dump the beams. By using the new data acquisition system, it was proved that the new BLM system shows a wide dynamic range of 160 dB. In this study, the details of the new data acquisition system are described.

  13. A Wireless Fatigue Monitoring System Utilizing a Bio-Inspired Tree Ring Data Tracking Technique

    Directory of Open Access Journals (Sweden)

    Shi Bai

    2014-03-01

    Full Text Available Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  14. A wireless fatigue monitoring system utilizing a bio-inspired tree ring data tracking technique.

    Science.gov (United States)

    Bai, Shi; Li, Xuan; Xie, Zhaohui; Zhou, Zhi; Ou, Jinping

    2014-03-05

    Fatigue, a hot scientific research topic for centuries, can trigger sudden failure of critical structures such as aircraft and railway systems, resulting in enormous casualties as well as economic losses. The fatigue life of certain structures is intrinsically random and few monitoring techniques are capable of tracking the full life-cycle fatigue damage. In this paper, a novel in-situ wireless real-time fatigue monitoring system using a bio-inspired tree ring data tracking technique is proposed. The general framework, methodology, and verification of this intelligent system are discussed in details. The rain-flow counting (RFC) method is adopted as the core algorithm which quantifies fatigue damages, and Digital Signal Processing (DSP) is introduced as the core module for data collection and analysis. Laboratory test results based on strain gauges and polyvinylidene fluoride (PVDF) sensors have shown that the developed intelligent system can provide a reliable quick feedback and early warning of fatigue failure. With the merits of low cost, high accuracy and great reliability, the developed wireless fatigue sensing system can be further applied to mechanical engineering, civil infrastructures, transportation systems, aerospace engineering, etc.

  15. Small-animal whole-body imaging using a photoacoustic full ring array system

    Science.gov (United States)

    Xia, Jun; Guo, Zijian; Aguirre, Andres; Zhu, Quing; Wang, Lihong V.

    2011-03-01

    In this report, we present a novel 3D photoacoustic computed tomography (PACT) system for small-animal whole-body imaging. The PACT system, based on a 512-element full-ring transducer array, received photoacoustic signals primarily from a 2-mm-thick slice. The light was generated by a pulse laser, and can either illuminate from the top or be reshaped to illuminate the sample from the side, using a conical lens and an optical condenser. The PACT system was capable of acquiring an in-plane image in 1.6 s; by scanning the sample in the elevational direction, a 3D tomographic image could be constructed. We tested the system by imaging a cylindrical phantom made of human hairs immersed in a scattering medium. The reconstructed image achieved an in-plane resolution of 0.1 mm and an elevational resolution of 1 mm. After deconvolution in the elevational direction, the 3D image was found to match well with the phantom. The system was also used to image a baby mouse in situ; the spinal cord and ribs can be seen easily in the reconstructed image. Our results demonstrate that the PACT system has the potential to be used for fast small-animal whole-body tomographic imaging.

  16. Research and Development on the Storage Ring Vacuum System for the APS Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Stillwell, B.; Brajuskovic, B.; Carter, J.; Cease, H.; Lill, R.; Navrotski, G.; Noonan, J.; Suthar, K.; Walters, D.; Wiemerslage, G.; Zientek, J.; Sangroula, M.

    2016-01-01

    A number of research and development activities are underway at Argonne National Laboratory to build confidence in the designs for the storage ring vacuum system required for the Advanced Photon Source Up-grade project (APS-U) [1]. The predominant technical risks are: excessive residual gas pressures during operation; insufficient beam position monitor stability; excessive beam impedance; excessive heating by induced electrical surface currents; and insufficient operational reliability. Present efforts to mitigate these risks include: building and evaluating mockup assemblies; performing mechanical testing of chamber weld joints; developing computational tools; investigating design alternatives; and performing electrical bench measurements. Status of these activities and some of what has been learned to date will be shared.

  17. Normal form and synchronization of strict-feedback chaotic systems

    International Nuclear Information System (INIS)

    Wang, Feng; Chen, Shihua; Yu Minghai; Wang Changping

    2004-01-01

    This study concerns the normal form and synchronization of strict-feedback chaotic systems. We prove that, any strict-feedback chaotic system can be rendered into a normal form with a invertible transform and then a design procedure to synchronize the normal form of a non-autonomous strict-feedback chaotic system is presented. This approach needs only a scalar driving signal to realize synchronization no matter how many dimensions the chaotic system contains. Furthermore, the Roessler chaotic system is taken as a concrete example to illustrate the procedure of designing without transforming a strict-feedback chaotic system into its normal form. Numerical simulations are also provided to show the effectiveness and feasibility of the developed methods

  18. Flux qubits on semiconducting quantum ring

    International Nuclear Information System (INIS)

    Szopa, M; Zipper, E

    2010-01-01

    The ability to control the quantum state of a single electrons in a quantum ring made of a semiconductor is at the heart of recent developments towards a scalable quantum computer. A peculiar dispersion relation of quantum rings allows to steer the ground state properties by the magnetic flux and offers spin and orbital degrees of freedom for quantum manipulations. We show that such ring can be effectively reduced to the two-state system forming a qubit on orbital or spin degrees of freedom.

  19. Transformation of Zwitterionic Pyridine Derivatives to a Spiro-Fused Ring System: Azoniabenzo[de]fluorine. Synthesis and Mechanistic Rationalization.

    Science.gov (United States)

    Palkó, Roberta; Egyed, Orsolya; Rokob, Tibor András; Bombicz, Petra; Riedl, Zsuzsanna; Hajós, György

    2015-01-02

    Reaction of aryl- and benzylsulfanopyridinium amidates bearing a methyl group in position 6 with 2 equiv of diphenylketene afforded a spiro-fused ring system: azoniabenzo[de]fluorine. By use of an excess amount of ketene, a distinct reaction was observed via which a 1H-pyrrolo[3,2-b]pyridin-2(3H)-one derivative was furnished. The structure of the tetracyclic spiro-fused ring system was unambiguously confirmed by X-ray diffraction, and its formation was rationalized by DFT calculations.

  20. Broadband feedback systems for the damping of coherent beam instabilities in the stretcher ring ELSA

    International Nuclear Information System (INIS)

    Roth, Andre

    2012-12-01

    At the Electron Stretcher Facility ELSA an upgrade of the internal beam current up to 200 mA would be desirable in order to increase the intensity of the extracted electron beam for the future experimental hadron physics program. However, such an upgrade is mainly limited by the excitation of coherent beam instabilities in the stretcher ring. As active counteraction, broadband bunch-by-bunch feedback-systems for the longitudinal, as well as for both transverse planes were installed. After detection of the motion of each of the 27 4 stored bunches via beam position monitors, the systems determine independent correction signals for each bunch using digital signal processors. The amplified correction signals are applied to the beam by means of broadband longitudinal and transverse kicker structures. The detailed setup, the commissioning procedure and measurement results of the damping performance of the systems are presented. In addition, the operation of the longitudinal system during the fast energy ramp of 4 GeV/s from 1.2 GeV to 3.2 GeV is investigated.

  1. Nonlinear effects of unbalance in the rotor-floating ring bearing system of turbochargers

    Science.gov (United States)

    Tian, L.; Wang, W. J.; Peng, Z. J.

    2013-01-01

    Turbocharger (TC) rotor-floating ring bearing (FRB) system is characterised by high speed as well as high non-linearity. Using the run-up and run-down simulation method, this paper systematically investigates the influence of unbalance on the rotordynamic characteristics of a real TC-FRB system over the speed range from 0 Hz to 3500 Hz. The rotor is discretized by the finite element method, and the desired oil film forces at each simulation step are calculated by an efficient analytical method. The imposed unbalance amount and distribution are the variables considered in the performed non-stationary simulations. The newly obtained results evidently show the distinct phenomena brought about by the variations of the unbalance offset, which confirms that the unbalance level is a critical parameter for the system response. In the meantime, the variations of unbalance distribution, i.e. out-of-phase and in-phase unbalance, can lead to entirely different simulation results as well, which proves the distribution of unbalance is not negligible during the dynamic analysis of the rotor-FRB system. Additionally, considerable effort has been placed on the description as well as discussion of a unique phenomenon termed Critical Limit Cycle Oscillation (CLC Oscillation), which is of great importance and interest to the TC research and development.

  2. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  3. A regression-based Kansei engineering system based on form feature lines for product form design

    Directory of Open Access Journals (Sweden)

    Yan Xiong

    2016-06-01

    Full Text Available When developing new products, it is important for a designer to understand users’ perceptions and develop product form with the corresponding perceptions. In order to establish the mapping between users’ perceptions and product design features effectively, in this study, we presented a regression-based Kansei engineering system based on form feature lines for product form design. First according to the characteristics of design concept representation, product form features–product form feature lines were defined. Second, Kansei words were chosen to describe image perceptions toward product samples. Then, multiple linear regression and support vector regression were used to construct the models, respectively, that predicted users’ image perceptions. Using mobile phones as experimental samples, Kansei prediction models were established based on the front view form feature lines of the samples. From the experimental results, these two predict models were of good adaptability. But in contrast to multiple linear regression, the predict performance of support vector regression model was better, and support vector regression is more suitable for form regression prediction. The results of the case showed that the proposed method provided an effective means for designers to manipulate product features as a whole, and it can optimize Kansei model and improve practical values.

  4. Development of a circular shape Si-PM-based detector ring for breast-dedicated PET system

    Science.gov (United States)

    Nakanishi, Kouhei; Yamamoto, Seiichi; Watabe, Hiroshi; Abe, Shinji; Fujita, Naotoshi; Kato, Katsuhiko

    2018-02-01

    In clinical situations, various breast-dedicated positron emission tomography (PET) systems have been used. However, clinical breast-dedicated PET systems have polygonal detector ring. Polygonal detector ring sometimes causes image artifact, so complicated reconstruction algorithm is needed to reduce artifact. Consequently, we developed a circular detector ring for breast-dedicated PET to obtain images without artifact using a simple reconstruction algorithm. We used Lu1.9Gd0.1SiO5 (LGSO) scintillator block which was made of 1.5 x 1.9 x 15 mm pixels that were arranged in an 8 x 24 matrix. As photodetectors, we used silicon photomultiplier (Si-PM) arrays whose channel size was 3 x 3 mm. A detector unit was composed of four scintillator blocks, 16 Si-PM arrays and a light guide. The developed detector unit had angled configuration since the light guide was bending. A detector unit had three gaps with an angle of 5.625° between scintillator blocks. With these configurations, we could arrange 64 scintillator blocks in nearly circular shape (regular 64-sided polygon) using 16 detector units. The use of the smaller number of detector units could reduce the size of the front-end electronics circuits. The inner diameter of the developed detector ring was 260 mm. This size was similar to those of brain PET systems, so our breast-dedicated PET detector ring can measure not only breast but also brain. Measured radial, tangential and axial spatial resolution of the detector ring reconstructed by the filtered back-projection (FBP) algorithm were 2.1 mm FWHM, 2.0 mm FWHM and 1.7 mm FWHM at center of field of view (FOV), respectively. The sensitivity was 2.0% at center of the axial FOV. With the developed detector ring, we could obtain high resolution image of the breast phantom and the brain phantom. We conclude that our developed Si-PM-based detector ring is promising for a high resolution breast-dedicated PET system that can also be used for brain PET system.

  5. Environmentally Benign Tribo-systems for Metal Forming

    DEFF Research Database (Denmark)

    Bay, Niels; Azushima, A.; Groche, P.

    2010-01-01

    The growing awareness of environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has initiated ever increasing efforts to develop new, environmentally benign tribological systems for metal forming. The present ...

  6. Pi overlapping ring systems contained in a homogeneous assay: a novel homogeneous assay for antigens

    Science.gov (United States)

    Kidwell, David A.

    1993-05-01

    A novel immunoassay, Pi overlapping ring systems contained in a homogeneous assay (PORSCHA), is described. This assay relies upon the change in fluorescent spectral properties that pyrene and its derivatives show with varying concentration. Because antibodies and other biomolecules can bind two molecules simultaneously, they can change the local concentration of the molecules that they bind. This concentration change may be detected spectrally as a change in the fluorescence emission wavelength of an appropriately labeled biomolecule. Several tests of PORSCHA have been performed which demonstrate this principle. For example: with streptavidin as the binding biomolecule and a biotin labeled pyrene derivative, the production of the excimer emitting at 470 nm is observed. Without the streptavidin present, only the monomer emitting at 378 and 390 nm is observed. The ratio of monomer to excimer provides the concentration of unlabeled biotin in the sample. Approximately 1 ng/mL of biotin may be detected with this system using a 50 (mu) l sample (2 X 10-16 moles biotin). The principles behind PORSCHA, the results with the streptavidin/biotin system are discussed and extensions of the PORSCHA concept to antibodies as the binding partner and DNA in homogeneous assays are suggested.

  7. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

    This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

  8. Study of photon–magnon coupling in a YIG-film split-ring resonant system

    Energy Technology Data Exchange (ETDEWEB)

    Bhoi, B.; Aiyar, R. [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); CRNTS, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Cliff, T.; Maksymov, I. S.; Kostylev, M., E-mail: mikhail.kostylev@uwa.edu.au [School of Physics M013, University of Western Australia, Crawley 6009 (Australia); Venkataramani, N. [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India); Prasad, S. [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Stamps, R. L. [School of Physics M013, University of Western Australia, Crawley 6009 (Australia); SUPA, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2014-12-28

    By using the stripline Microwave Vector–Network Analyser Ferromagnetic Resonance and Time Domain spectroscopy techniques, we study a strong coupling regime of magnons to microwave photons in the planar geometry of a lithographically formed split-ring resonator (SRR) loaded by a single-crystal epitaxial yttrium–iron–garnet (YIG) film. Strong anti-crossing of the photon modes of SRR and of the magnon modes of the YIG film is observed in the applied-magnetic-field resolved measurements. The coupling strength extracted from the experimental data reaches 9% at 3 GHz. Theoretically, we propose an equivalent circuit model of the SRR loaded by a magnetic film. This model follows from the results of our numerical simulations of the microwave field structure of the SRR and of the magnetisation dynamics in the YIG film driven by the microwave currents in the SRR. The results obtained with the equivalent-circuit model are in good agreement with the experiment. This model provides a simple physical explanation of the process of mode anti-crossing. Our findings are important for future applications in microwave quantum photonic devices as well as in nonlinear and magnetically tuneable metamaterials exploiting the strong coupling of magnons to microwave photons.

  9. Biocompatibility and Systemic Safety of a Novel Implantable Annuloplasty Ring for the Treatment of Mitral Regurgitation in a Minipig Model.

    Science.gov (United States)

    Ramot, Yuval; Rousselle, Serge D; Yellin, Nadav; Willenz, Udi; Sabag, Itai; Avner, Avi; Nyska, Abraham

    2016-07-01

    Prosthetic annuloplasty rings are a common treatment modality for mitral regurgitation, and recently, percutaneous implantation techniques have gained popularity due to their favorable safety profile. Although in common use, biocompatibility of annuloplasty rings has been reported only sparsely in the literature, and none of these reports used the percutaneous technique of implantation. We report on the biocompatibility and the systemic safety of a novel transcatheter mitral valve annuloplasty ring (AMEND™) in 6 minipigs. This device is composed of a nitinol tube surrounded by a braided polyethylene terephthalate fabric tube. The device produced no adverse inflammatory response, showing gradual integration between the metal ring and the fabric by normal host fibrocellular response, leading to complete neoendocardium coverage. There was no evidence for adverse reactions, rejection, or intolerance in the valvular structure. In 2 animals, hemopericardium resulted from the implantation procedure, leading to right-sided cardiac insufficiency with pulmonary edema and liver congestion. The findings reported herein can serve as a case study for the expected healing pathology reactions after implantation of transcatheter mitral valve annuloplasty rings. © The Author(s) 2016.

  10. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  11. The design of the optical components and gas control systems of the CERN Omega Ring Imaging Cerenkov Detector

    International Nuclear Information System (INIS)

    Apsimon, R.J.; Cowell, J.; Flower, P.S.

    1985-06-01

    A large Ring Imaging Cerenkov Detector (RICH) has been commissioned for use at the CERN Omega Spectrometer. The general design of the device is discussed, and the dependence of the attainable spatial resolution and range of particle identification on its optical parameters is illustrated. The construction and performance of the major optical components and gas systems of the detector are also described. (author)

  12. Explicitly-correlated ring-coupled-cluster-doubles theory: Including exchange for computations on closed-shell systems

    Energy Technology Data Exchange (ETDEWEB)

    Hehn, Anna-Sophia; Holzer, Christof; Klopper, Wim, E-mail: klopper@kit.edu

    2016-11-10

    Highlights: • Ring-coupled-cluster-doubles approach now implemented with exchange terms. • Ring-coupled-cluster-doubles approach now implemented with F12 functions. • Szabo–Ostlund scheme (SO2) implemented for use in SAPT. • Fast convergence to the limit of a complete basis. • Implementation in the TURBOMOLE program system. - Abstract: Random-phase-approximation (RPA) methods have proven to be powerful tools in electronic-structure theory, being non-empirical, computationally efficient and broadly applicable to a variety of molecular systems including small-gap systems, transition-metal compounds and dispersion-dominated complexes. Applications are however hindered due to the slow basis-set convergence of the electron-correlation energy with the one-electron basis. As a remedy, we present approximate explicitly-correlated RPA approaches based on the ring-coupled-cluster-doubles formulation including exchange contributions. Test calculations demonstrate that the basis-set convergence of correlation energies is drastically accelerated through the explicitly-correlated approach, reaching 99% of the basis-set limit with triple-zeta basis sets. When implemented in close analogy to early work by Szabo and Ostlund [36], the new explicitly-correlated ring-coupled-cluster-doubles approach including exchange has the perspective to become a valuable tool in the framework of symmetry-adapted perturbation theory (SAPT) for the computation of dispersion energies of molecular complexes of weakly interacting closed-shell systems.

  13. CHICSi - a 3π multi-detector system for studying heavy ion interactions inside a storage ring

    International Nuclear Information System (INIS)

    Avdeichikov, V.; Carlen, L.; Fokin, A.; Jakobsson, J.; Murin, Yu.; Maartensson, J.; Oskarsson, A.; van Veldhuizen, E.J.; Westerberg, L.; Whitlow, H.J.

    1996-01-01

    CHICSi - a 3π multi-detector system is presented. The setup consists of 576 ultra high vacuum compatible telescopes to study intermediate energy heavy ion as well as proton induced collisions at storage rings operating in slow ramping mode. Primary it will be installed at the gas-jet target station of the CELSIUS facility at The Svedberg Laboratory in Uppsala. (orig.)

  14. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  15. Novel Zinc-Catalytic Systems for Ring-Opening Polymerization of ε-Caprolactone

    Directory of Open Access Journals (Sweden)

    Karolina Żółtowska

    2015-02-01

    Full Text Available Polycaprolactone (PCL is a biodegradable synthetic polymer that is currently widely used in many pharmaceutical and medical applications. In this paper we describe the coordination ring-opening polymerization of ε-caprolactone in the presence of two newly synthesized catalytic systems: diethylzinc/gallic acid and diethylzinc/propyl gallate. The chemical structures of the obtained PCLs were characterized by 1H- or 13C-NMR, FTIR spectroscopy and MALDI TOF mass spectrometry. The average molecular weight of the resulting polyesters was analysed by gel permeation chromatography and a viscosity method. The effects of temperature, reaction time and type of catalytic system on the polymerization process were examined. Linear PCLs with defined average molecular weight were successfully obtained. Importantly, in some cases the presence of macrocyclic products was not observed during the polymerization process. This study provides an effective method for the synthesis of biodegradable polyesters for medical and pharmaceutical applications due to the fact that gallic acid/propyl gallate are commonly used in the pharmaceutical industry.

  16. The aerogel Ring Imaging Cherenkov system at the Belle II spectrometer

    Science.gov (United States)

    Pestotnik, R.; Adachi, I.; Dolenec, R.; Hataya, K.; Iori, S.; Iwata, S.; Kakuno, H.; Kataura, R.; Kawai, H.; Kindo, H.; Kobayashi, T.; Korpar, S.; Križan, P.; Kumita, T.; Mrvar, M.; Nishida, S.; Ogawa, K.; Ogawa, S.; Šantelj, L.; Sumiyoshi, T.; Tabata, M.; Yonenaga, M.; Yusa, Y.

    2017-12-01

    In the forward end-cap of the Belle II spectrometer, a proximity focusing Ring Imaging Cherenkov counter with an aerogel radiator will be installed. The detector will occupy a limited space inside solenoid magnet with longitudinal field of 1.5 T. It will consist of a double layer aerogel radiator, an expansion volume and a photon detector. 420 Hamamatsu hybrid avalanche photo sensors with 144 channels each will be used to read out single Cherenkov photons with high efficiency. More than 60,000 analog signals will be digitized and processed in the front end electronics and send to the unified experiment data acquisition system. The detector components have been successfully produced and are now being installed in the spectrometer. Tested before on the bench, they are currently being installed in the mechanical frame. Part of the detector have been commissioned and connected to the acquisition system to register the cosmic ray particles. The first preliminary results are in accordance with previous expectations. We expect an excellent performance of the device which will allow at least a 4σ separation of pions from kaons in the experiment kinematic region from 0.5 GeV/c to 4 GeV/c.

  17. Cooling system for the connecting rings of a fast neutron reactor vessel

    International Nuclear Information System (INIS)

    Martin, J.-P.; Malaval, Claude

    1974-01-01

    A description is given of a cooling system for the vessel connecting rings of a fast neutron nuclear reactor, particularly of a main vessel containing the core of the reactor and a volume of liquid metal coolant at high temperature and a safety vessel around the main vessel, both vessels being suspended to a rigid upper slab kept at a lower temperature. It is mounted in the annular space between the two vessels and includes a neutral gas circuit set up between the wall of the main vessel to be cooled and that of the safety vessel itself cooled from outer. The neutral gas system comprises a plurality of ventilators fitted in holes made through the thickness of the upper slab and opening on to the space between the two vessels. It also includes two envelopes lining the walls of these vessels, establishing with them small section channels for the circulation of the neutral gas cooled against the safety vessel and heated against the main vessel [fr

  18. Experimental Observation of Fermi-Pasta-Ulam Recurrence in a Nonlinear Feedback Ring System

    Science.gov (United States)

    Wu, Mingzhong; Patton, Carl E.

    2007-01-01

    Fermi-Pasta-Ulam recurrence through soliton dynamics has been realized. The experiment used a magnetic film strip-based active feedback ring. At some ring gain level, a wide spin wave pulse is self-generated in the ring. As the pulse circulates, it separates into two envelop solitons with different speeds. When the fast soliton catches up and collides with the slow soliton, the initial wide pulse is perfectly reconstructed. The repetition of this process leads to periodic recurrences of the initial pulse.

  19. A RING/DISK/OUTFLOW SYSTEM ASSOCIATED WITH W51 NORTH: A VERY MASSIVE STAR IN THE MAKING

    International Nuclear Information System (INIS)

    Zapata, Luis A.; Schilke, Peter; Menten, Karl; Ho, Paul T. P.; Rodriguez, Luis F.; Palau, Aina; Garrod, Robin T.

    2009-01-01

    Sensitive and high angular resolution (∼0.''4) SO 2 [22 2,20 → 22 1,21 ] and SiO[5 → 4] line and 1.3 and 7 mm continuum observations made with the Submillimeter Array (SMA) and the Very Large Array (VLA) toward the young massive cluster W51 IRS2 are presented. We report the presence of a large (of about 3000 AU) and massive (40 M sun ) dusty circumstellar disk and a hot gas molecular ring around a high-mass protostar or a compact small stellar system associated with W51 North. The simultaneous observations of the silicon monoxide molecule, an outflow gas tracer, further revealed a massive (200 M sun ) and collimated (∼14 0 ) outflow nearly perpendicular to the dusty and molecular structures suggesting thus the presence of a single very massive protostar with a bolometric luminosity on the order of 10 5 L sun . A molecular hybrid local thermodynamic equilibrium model of a Keplerian and infalling disk with an inner cavity and a central stellar mass of more than 60 M sun agrees well with the SO 2 [22 2,20 → 22 1,21 ] line observations. Finally, these results suggest that mechanisms, such as mergers of low- and intermediate-mass stars, might not be necessary for forming very massive stars.

  20. Film forming systems for topical and transdermal drug delivery

    Directory of Open Access Journals (Sweden)

    Kashmira Kathe

    2017-11-01

    Full Text Available Skin is considered as an important route of administration of drugs for both local and systemic effects. The effectiveness of topical therapy depends on the physicochemical properties of the drug and adherence of the patient to the treatment regimen as well as the system's ability to adhere to skin during the therapy so as to promote drug penetration through the skin barrier. Conventional formulations for topical and dermatological administration of drugs have certain limitations like poor adherence to skin, poor permeability and compromised patient compliance. For the treatment of diseases of body tissues and wounds, the drug has to be maintained at the site of treatment for an effective period of time. Topical film forming systems are such developing drug delivery systems meant for topical application to the skin, which adhere to the body, forming a thin transparent film and provide delivery of the active ingredients to the body tissue. These are intended for skin application as emollient or protective and for local action or transdermal penetration of medicament for systemic action. The transparency is an appreciable feature of this polymeric system which greatly influences the patient acceptance. In the current discussion, the film forming systems are described as a promising choice for topical and transdermal drug delivery. Further the various types of film forming systems (sprays/solutions, gels and emulsions along with their evaluation parameters have also been reviewed.

  1. Glass Forming Ability in Systems with Competing Orderings

    Science.gov (United States)

    Russo, John; Romano, Flavio; Tanaka, Hajime

    2018-04-01

    Some liquids, if cooled rapidly enough to avoid crystallization, can be frozen into a nonergodic glassy state. The tendency for a material to form a glass when quenched is called "glass-forming ability," and it is of key significance both fundamentally and for materials science applications. Here, we consider liquids with competing orderings, where an increase in the glass-forming ability is signaled by a depression of the melting temperature towards its minimum at triple or eutectic points. With simulations of two model systems where glass-forming ability can be tuned by an external parameter, we are able to interpolate between crystal-forming and glass-forming behavior. We find that the enhancement of the glass-forming ability is caused by an increase in the structural difference between liquid and crystal: stronger competition in orderings towards the melting point minimum makes a liquid structure more disordered (more complex). This increase in the liquid-crystal structure difference can be described by a single adimensional parameter, i.e., the interface energy cost scaled by the thermal energy, which we call the "thermodynamic interface penalty." Our finding may provide a general physical principle for not only controlling the glass-forming ability but also the emergence of glassy behavior of various systems with competing orderings, including orderings of structural, magnetic, electronic, charge, and dipolar origin.

  2. Warden’s Five-Ring System Theory: Legitimate Wartime Military Targeting or an Increased Potential to Violate the Law and Norms of Expected Behavior?

    Science.gov (United States)

    2000-04-01

    the five-ring system theory that dramatically improves the warfighters ability to systematically identify wartime targets. However, for all of its...acclaim, little has been written about Warden’s five-ring system theory . Even less has been written about the legal and moral implications of using Warden’s theory to identify wartime targets.

  3. RF-to-RF Characterization of a Phased Array Receive Antenna Steering System Using a Novel Ring Resonator-Based Integrated Photonic Beamformer

    NARCIS (Netherlands)

    Zhuang, L.; Burla, M.; Roeloffzen, C.G.H.; Meijerink, Arjan; Marpaung, D.A.I.; Khan, M.R.H.; van Etten, Wim; Leinse, Arne; Hoekman, M.; Heideman, Rene

    2009-01-01

    A novel ring resonator-based photonic beamformer has been developed for continuous and squint-free control of the reception angle of broadband phased array antenna systems. The core of the system is a ring resonator based optical beamforming network (OBFN) used for delay synchronization and coherent

  4. The Ring System of Saturn as Seen by Cassini-VIMS (Invited)

    Science.gov (United States)

    Filacchione, G.; Ciarniello, M.; Capaccioni, F.

    2015-08-01

    Since 2004 the Visual and Infrared Mapping Spectrometer (VIMS) aboard Cassini has acquired numerous hyperspectral mosaics in the 0.35-5.1 μm spectral range of Saturn's main rings in very different illumination and viewing geometries. These observations have allowed us to infer the ring particles physical properties and composition: water ice abundance is estimated through the 1.25-1.5-2.0 μm band depths, chromophores distribution is derived from visible spectral slopes while organic material is traced by the aliphatic compounds signature at 3.42 μm which appears stronger on CD and C ring than on A-B rings (Filacchione et al., 2014). Observed reflectance spectra are fitted with a spectrophotometric model based on Montecarlo ray-tracing with the scope to infer particles composition while disentangling photometric effects (caused by multiple scattering, opposition surge and forward scattering) which depend on illumination/viewing geometries. Spectral bond albedo for different regions of the rings has been best-fitted using Hapke's radiative transfer modeling (Ciarniello et al, 2011) by choosing different mixtures of water ice, tholin, and amorphous carbon particles populations. While tholin distribution seems to be fairly constant across the rings, the amorphous carbon appears anti-correlated with optical depth. Moreover, dark material contamination is less effective on densest regions, where the more intense rejuvenation processes occur, in agreement with the ballistic transport theory (Cuzzi and Estrada,1998). Finally, the 3.6 μm continuum peak wavelength is used to infer particles temperature, which is anti-correlated with the albedo and the optical depth (tau): low-albedo/low-tau C ring and CD have higher temperatures than A-B rings where albedo and tau are high. This trend matches direct temperature measurements by CIRS (Spilker et al., 2013).

  5. A novel system for commissioning brachytherapy applicators: example of a ring applicator

    Science.gov (United States)

    Fonseca, Gabriel P.; Van den Bosch, Michiel R.; Voncken, Robert; Podesta, Mark; Verhaegen, Frank

    2017-11-01

    A novel system was developed to improve commissioning and quality assurance of brachytherapy applicators used in high dose rate (HDR). It employs an imaging panel to create reference images and to measure dwell times and dwell positions. As an example: two ring applicators of the same model were evaluated. An applicator was placed on the surface of an imaging panel and a HDR 192Ir source was positioned in an imaging channel above the panel to generate an image of the applicator, using the gamma photons of the brachytherapy source. The applicator projection image was overlaid with the images acquired by capturing the gamma photons emitted by the source dwelling inside the applicator. We verified 0.1, 0.2, 0.5 and 1.0 cm interdwell distances for different offsets, applicator inclinations and transfer tube curvatures. The data analysis was performed using in-house developed software capable of processing the data in real time, defining catheters and creating movies recording the irradiation procedure. One applicator showed up to 0.3 cm difference from the expected position for a specific dwell position. The problem appeared intermittently. The standard deviations of the remaining dwell positions (40 measurements) were less than 0.05 cm. The second ring applicator had a similar reproducibility with absolute coordinate differences from expected values ranging from  -0.10 up to 0.18 cm. The curvature of the transfer tube can lead to differences larger than 0.1 cm whilst the inclination of the applicator showed a negligible effect. The proposed method allows the verification of all steps of the irradiation, providing accurate information about dwell positions and dwell times. It allows the verification of small interdwell positions (⩽0.1 cm) and reduces measurement time. In addition, no additional radiation source is necessary since the HDR 192Ir source is used to generate an image of the applicator.

  6. Intravaginal rings as delivery systems for microbicides and multipurpose prevention technologies

    Directory of Open Access Journals (Sweden)

    Thurman AR

    2013-10-01

    Full Text Available Andrea Ries Thurman, Meredith R Clark, Jennifer Hurlburt, Gustavo F Doncel CONRAD, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, VA, USA Abstract: There is a renewed interest in delivering pharmaceutical products via intravaginal rings (IVRs. IVRs are flexible torus-shaped drug delivery systems that can be easily inserted and removed by the woman and that provide both sustained and controlled drug release, lasting for several weeks to several months. In terms of women's health care products, it has been established that IVRs effectively deliver contraceptive steroids and steroids for the treatment of postmenopausal vaginal atrophy. A novel application for IVRs is the delivery of antiretroviral drugs for the prevention of human immunodeficiency virus (HIV genital infection. Microbicides are antiviral drugs delivered topically for HIV prevention. Recent reviews of microbicide IVRs have focused on technologies in development and optimizing ring design. IVRs have several advantages, including the ability to deliver sustained drug doses for long periods of time while bypassing first pass metabolism in the gut. IVRs are discreet, woman-controlled, and do not require a trained provider for placement or fitting. Previous data support that women and their male sexual partners find IVRs highly acceptable. Multipurpose prevention technology (MPT products provide protection against unintended/mistimed pregnancy and reproductive tract infections, including HIV. Several MPT IVRs are currently in development. Early clinical testing of new microbicide and MPT IVRs will require a focus on safety, pharmacokinetics and pharmacodynamics. Specifically, IVRs will have to deliver tissue concentrations of drugs that are pharmacodynamically active, do not cause mucosal alterations or inflammation, and do not change the resident microbiota. The emergence of resistance to antiretrovirals will need to be investigated. IVRs should not

  7. Vacuum system for the test accumulation ring for the NUMATRON project (TARN)

    International Nuclear Information System (INIS)

    Mizobuchi, Akira

    1979-01-01

    The vacuum system for the test accumulation ring for the NUMATRON project (TARN) being constructed in the Institute for Nuclear Study, University of Tokyo, for the purpose of accumulating fundamental data on high energy, heavy ion acceleration is presented. The main specifications of TARN are as follows: repetition rate 1 Hz, average radius 5.06 m, the radius of curvature 1.333 m, circumference 31.795 m, the length of a unit cell 3.974 m, the length of a long straight section 1.8 m, the number of unit cells 8, superperiodicity 8, and the structure of a unit cell FODO. The vacuum level of TARN lower than 1 x 10 -10 Torr is necessary. The preliminary test apparatuses, number one and two, for obtaining the basic data on superhigh vacuum were constructed. The characteristics of a molecular vacuum pump and the high temperature baking effect were tested with the number one test apparatus. The glow discharge cleaning effect of the model vacuum chamber for deflecting magnets was tested, utilizing the number two test apparatus. The pressure curve in course of time during pump down, the residual gas components, the residual gas spectrum in vacuum state and the change of residual gas components before and after the glow discharge cleaning are shown as these testing results. The vacuum gauges, which are used for TARN for measuring both the total pressure and the partial pressure of gas, are explained. The vacuum system, the vacuum chamber, the vacuum pumps, the expected exhausting speed and the partial functional test results for the vacuum system are introduced. (Nakai, Y.)

  8. Beam-Forming Concentrating Solar Thermal Array Power Systems

    Science.gov (United States)

    Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

    2016-01-01

    The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

  9. On the Aharonov-Casher system and the Landau-Aharonov-Casher system confined to a two-dimensional quantum ring

    International Nuclear Information System (INIS)

    Bakke, K.; Furtado, C.

    2012-01-01

    We study the quantum dynamics of a neutral particle in the Aharonov-Casher system and in the Landau-Aharonov-Casher system confined to a two-dimensional quantum ring, a quantum dot, and a quantum anti-dot potentials described by the Tan-Inkson model [W.-C. Tan and J. C. Inkson, Semicond. Sci. Technol. 11, 1635 (1996)]. We show, in the Aharonov-Casher system, that bound states can be achieved when the neutral particle is confined to the two-dimensional quantum ring and the quantum dot and discuss the appearance of persistent currents. In the Landau-Aharonov-Casher system, we show that bound states can be achieved when the neutral particle is confined to the quantum anti-dot, quantum dot, and the two-dimensional quantum ring, but there are no persistent currents.

  10. Temperature dependence of the anisotropy of fluorescence in ring molecular systems

    International Nuclear Information System (INIS)

    Herman, Pavel; Barvik, Ivan

    2007-01-01

    The time dependence of the anisotropy of fluorescence after an impulsive excitation in the molecular ring (resembling the B850 ring of the purple bacterium Rhodopseudomonas acidophila) is calculated. Fast fluctuations of the environment are simulated by dynamic disorder and slow fluctuations by uncorrelated static disorder. Without dynamic disorder modest degrees of static disorder are sufficient to cause the experimentally found initial drop of the anisotropy on a sub-100 fs time scale. In the present investigation we are comparing results for the time-dependent optical anisotropy of the molecular ring for four models of the uncorrelated static disorder: Gaussian disorder in the local energies (model A), Gaussian disorder in the transfer integrals (model B), Gaussian disorder in radial positions of molecules (model C) and Gaussian disorder in angular positions of molecules (model D). Both types of disorder-static and dynamic-are taken into account simultaneously

  11. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  12. One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes

    Directory of Open Access Journals (Sweden)

    Priyabrata Roy

    2010-05-01

    Full Text Available One-pot three-component coupling of o-alkynylheteroaryl carbonyl derivatives with Fischer carbene complexes and dienophiles leading to the synthesis of quinoxaline and phenazine ring systems has been investigated. This involves the generation of furo[3,4-b]pyrazine and furo[3,4-b]quinoxaline as transient intermediates, which were trapped with Diels–Alder dienophiles. This is the first report on furo[3,4-b]pyrazine intermediates.

  13. Ring coil optimization with respect to stress, temperature, and system energy over a range of physics requirements

    International Nuclear Information System (INIS)

    Pillsbury, R.D. Jr; Thome, R.J.

    1987-01-01

    The poloidal field coil system for a tokamak can be divided into the central solenoid and the ring coils. A ring coil is defined as one that has a small cross-section compared to its diameter. The size of the central solenoid is usually fixed very early in the design process since its size is directly related to the tokamak size. The sizes of the other (ring) coils are not as critical to determining the basic machine size. It is necessary to know their locations and currents in order to verify the shaping and position control of the plasma. Attention is usually focused only on the baseline plasma of the design point. However, the PF set must also be able to shape and maintain other plasmas. This paper describes a program which evaluates PF coil current scenarios over a range of physics requirements and determines the sizes of the coils necessary to satisfy constraints on the temperature rise and stress levels for the worst case scenario. In addition, the system energy requirements can be assessed and trade-offs between system energy and coil sizes (cost) can be made. Examples are given based on studies performed of CIT (Compact Ignition Tokamak)

  14. Stability of driven systems with growing gaps, quantum rings, and Wannier ladders

    Czech Academy of Sciences Publication Activity Database

    Asch, J.; Duclos, P.; Exner, Pavel

    1998-01-01

    Roč. 92, 5/6 (1998), s. 1053-1070 ISSN 0022-4715 R&D Projects: GA AV ČR(CZ) IAA148409 Keywords : quantum stability * energy expectations * driven rings Subject RIV: BE - Theoretical Physics Impact factor: 1.469, year: 1998

  15. A System of Test Methods for Sheet Metal Forming Tribology

    DEFF Research Database (Denmark)

    Bay, Niels; Olsson, David Dam; Andreasen, Jan Lasson

    2007-01-01

    Sheet metal forming of tribologically difficult materials such as stainless steel, Al-alloys and Ti-alloys or forming in tribologically difficult operations like ironing, punching or deep drawing of thick plate requires often use of environmentally hazardous lubricants such as chlorinated paraffin...... oils in order to avoid galling. The present paper describes a systematic research in the development of new, environmentally harmless lubricants focusing on the lubricant testing aspects. A system of laboratory tests has been developed to study the lubricant performance under the very varied conditions...... appearing in different sheet forming operations such as stamping, deep drawing, ironing and punching. The laboratory tests have been especially designed to model the conditions in industrial production....

  16. Ordered one-component plasmas: Phase transitions, normal modes, large systems, and experiments in a storage ring

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1994-01-01

    The property of cold one-component plasmas, confined by external forces, to form an ordered array has been known for some time both from simulations and from experiment. The purpose of this talk is to summarize some recent work on simulations and some new experimental results. The author discusses some experimental work on real storage rings, magnetic storage devices in which partials circulate with large kinetic energies and for which laser cooling is used on partially ionized ions to attain temperatures ten or more orders of magnitude lower than their kinetic energies

  17. Systemic and intracardiac hemodynamic disturbance in complicated forms of hepatocirrhosis

    International Nuclear Information System (INIS)

    Mjasnik, B.N.; Chodzibekov, M.C.; Achmedzanova, S.S.

    1990-01-01

    On the base of radionuclide investigation of systemic and intracardiac hemodynamics was shown that the rate of kinetic variants of hemocirculation does not depend on the stage of portal hypertension in complicated forms of hepatocirrhosis. Blood redistribution in these patients creates volumentrical overload of cardiac ventricles and pulmonary circulation, that is conditioned of additional tension of cardiac muscle and especially of right ventricle myocardium, which reserve rapidly ran out. Operations which increase blood shunt from portal system to superior vena cava raise preload of myocardium that makes the high risk in appearance of cardiac insufficiency, especially of right ventricle in early post operative period. The received data indicated on necessity to take into account the state of intracardiac hemodynamics in selection of surgical approach in patients with complicated forms of hepatocirrhosis. (orig.) [de

  18. Embedding the Form Generator in a Content Management System

    Science.gov (United States)

    Delgado, A.; Wicenec, A.; Delmotte, N.; Tejero, A.

    2008-08-01

    Given the tremendous amount of data generated by ESO's telescopes and the rapid evolution of the World Wide Web, the ESO archive web interface needs to offer more flexible services and advanced functionalities to a growing community of users all over the world. To achieve this endeavour, a query form generator is being developed inside a Content Management System. We present here a progress report.

  19. Synchronization of complex chaotic systems in series expansion form

    International Nuclear Information System (INIS)

    Ge Zhengming; Yang Chenghsiung

    2007-01-01

    This paper studies the synchronization of complex chaotic systems in series expansion form by Lyapunov asymptotical stability theorem. A sufficient condition is given for the asymptotical stability of an error dynamics, and is applied to guiding the design of the secure communication. Finally, numerical results are studied for the Quantum-CNN oscillators synchronizing with unidirectional/bidirectional linear coupling to show the effectiveness of the proposed synchronization strategy

  20. Form of Government and Political System: Conditions of Impossibility

    Directory of Open Access Journals (Sweden)

    Bogdan Iancu

    2012-12-01

    Full Text Available Successful constitutions manage to predetermine in juridical frame the political life of a country, by imposing a durable core equilibrium, i.e., a specific political system. The integrative function of the constitution derives from a reflexive political decision, at the constitution-making moment, for a specific form. The current theoretical difficulty in characterizing with precision the political system established by the Constitution of 1991 reflects the syncopated constitutional conflicts of recent years. The instability can be traced back to the continued absence of the preconditions for a genuine constitutional foundation. The initial indecision has been reinforced by later influences, including the EU accession process.

  1. Useful forms of the Hamiltonian for ion-optical systems

    International Nuclear Information System (INIS)

    Davies, W.G.

    1991-04-01

    The symbiosis of differential algebra and the Lie-algebraic formulation of optics provides a set of very powerful tools for analyzing and understanding the orbit dynamics of complex accelerators up to very high orders. In order to use these tools effectively it is usually necessary to express the Hamiltonian in the appropriate coordinate system. In this report, the relativistic Hamiltonian is derived in curvilinear (the fundamental coordinate system for ion-optics), Cartesian and polar coordinates, in forms suitable for solving problems in ion optics and accelerator physics both with and without the help of differential algebra

  2. Operation of radiation monitoring system in radwaste form test facility

    International Nuclear Information System (INIS)

    Ryu, Young Gerl; Kim, Ki Hong; Lee, Jae Won; Kwac, Koung Kil

    1998-08-01

    RWFTF (RadWaste Form Test Facility) must have a secure radiation monitoring system (RMS) because of having a hot-cell capable of handling high radioactive materials. And then in controlled radiation zone, which is hot-cell and its maintenance and operation / control room, area dose rate, radioactivities in air-bone particulates and stack, and surface contamination are monitored continuously. For the effective management such as higher utilization, maintenance and repair, the status of this radiation monitoring system, the operation and characteristics of all kinds of detectors and other parts of composing this system, and signal treatment and its evaluation were described in this technical report. And to obtain the accuracy detection results and its higher confidence level, the procedure such as maintenance, functional check and system calibration were established and appended to help the operation of RMS. (author). 6 tabs., 30 figs

  3. AFOCAL SYSTEMS FORMED BY MIRROR OFF-AXIS PARABOLOID

    Directory of Open Access Journals (Sweden)

    N. K. Artiukhina

    2017-01-01

    Full Text Available Mirror systems make it possible to reduce device dimensions and its weight while preserving high input aperture and these systems are characterized by a number of other advantages. Their significant disadvantage is a central screening of an entrance pupil that leads to lower image quality. The paper contains description of the investigations on afocal systems formed by eccentrically cut-out mirror paraboloids (off-axis mirrors where aperture diaphragm is displaced in the meridian plane for a defined value and a central field point is located on the optical axis. The canonic Mersenne systems are accepted as base schemas (modules for these compositions. The paper considers two types of such systems: visible increases – Г > 0 and Г < 0. Algorithms for calculation of centered afocal systems with two and four reflections have been written in the paper and the systems are free from spherical aberration, coma, astigmatism when an input pupil is located in superimposed focal planes of all parabolic mirrors. An aberration in curvature image has been additionally corrected in three-mirror quart-parabolic scheme which is a combination of two classical telescopic Mersenne systems. The paper presents schemes and calculation results. Two-mirror schemes with non-screened input pupil have been studied in the paper and in this case all the system remains centered and an aperture diaphragm is decentered for the distance Cm which is commensurable with the diaphragm size. The paper contains description of the investigated afocal schemes with four reflections from off-axis mirror paraboloids, a prepared algorithm for calculation, the obtained formulas for making combination of canonic afocal systems formed by two mirrors. Computer simulation in software environment Opal and Zemax has been carried out in the paper. Basic description has been prepared while using two alternative methods for the class of decentered systems and aberration characteristics and

  4. Implementation status of the global and local beam position feedback systems for the Advanced Photon Source storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Barr, D.; Decker, G.; Galayda, J.; Kirchman, J.; Lenkszus, F.; Lumpkin, A.; Votaw, A.J.

    1995-01-01

    The Advanced Photon Source (APS) is implementing an extensive beam position feedback system for both global and local stabilization of particle and photon beams based on digital signal processing. The description and operational experience of the system will be given in this paper. In particular, we will discuss the underlying fundamental principles, hardware layout, controls interface, and automatic software generation for multiple digital signal processors (DSPS) distributed in 20 VME crates around the ring. The feedback system runs at 4-kHz sampling frequency in order to achieve the correction bandwidth of approximately 100 Hz. For the maximum correction efficiency and resolution of conflicts among multiple local feedback systems due to the local bump closure error, the global and local feedback systems are combined into a single unified system. This novel approach is made possible through data sharing among the global and local systems via the fiber-optically networked reflective memories

  5. Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Stillwell, B.; Billett, B.; Brajuskovic, B.; Carter, J.; Kirkus, E.; Lale, M.; Lerch, J.; Noonan, J.; O' Neill, M.; Rocke, B.; Suthar, K.; Walters, D.; Wiemerslage, G.; Zientek, J.

    2017-06-20

    Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction and rf cavity straight sections. An overview of progress in these areas is presented.

  6. Analysis of image plane's Illumination in Image-forming System

    International Nuclear Information System (INIS)

    Duan Lihua; Zeng Yan'an; Zhang Nanyangsheng; Wang Zhiguo; Yin Shiliang

    2011-01-01

    In the detection of optical radiation, the detecting accuracy is affected by optic power distribution of the detector's surface to a large extent. In addition, in the image-forming system, the quality of the image is greatly determined by the uniformity of the image's illumination distribution. However, in the practical optical system, affected by the factors such as field of view, false light and off axis and so on, the distribution of the image's illumination tends to be non uniform, so it is necessary to discuss the image plane's illumination in image-forming systems. In order to analyze the characteristics of the image-forming system at a full range, on the basis of photometry, the formulas to calculate the illumination of the imaging plane have been summarized by the numbers. Moreover, the relationship between the horizontal offset of the light source and the illumination of the image has been discussed in detail. After that, the influence of some key factors such as aperture angle, off-axis distance and horizontal offset on illumination of the image has been brought forward. Through numerical simulation, various theoretical curves of those key factors have been given. The results of the numerical simulation show that it is recommended to aggrandize the diameter of the exit pupil to increase the illumination of the image. The angle of view plays a negative role in the illumination distribution of the image, that is, the uniformity of the illumination distribution can be enhanced by compressing the angle of view. Lastly, it is proved that telecentric optical design is an effective way to advance the uniformity of the illumination distribution.

  7. Beam forming system modernization at the MMF linac proton injector

    CERN Document Server

    Derbilov, V I; Nikulin, E S; Frolov, O T

    2001-01-01

    The isolation improvements of the beam forming system (BFS) of the MMF linac proton injector ion source are reported. The mean beam current and,accordingly, BFS electrode heating were increased when the MMF linac has began to operate regularly in long beam sessions with 50 Hz pulse repetition rate. That is why the BFS electrode high-voltage isolation that was made previously as two consequently and rigidly glued solid cylinder insulators has lost mechanical and electric durability. The substitution of large (160 mm) diameter cylinder insulator for four small diameter (20 mm) tubular rods has improved vacuum conditions in the space of beam forming and has allowed to operate without failures when beam currents being up to 250 mA and extraction and focusing voltage being up to 25 and 40 kV respectively. Moreover,the construction provides the opportunity of electrode axial move. The insulators are free from electrode thermal expansion mechanical efforts in a transverse direction.

  8. Technological study of ring and compact spinning systems for the manufacturing of slub fancy yarn under multiple slub variations and its effect on woven fabric

    International Nuclear Information System (INIS)

    Mahmood, N.; Iftikhar, M.; Mahmood, T.; Arshad, M.

    2009-01-01

    Textile technologies are continuously evolving with the objects both of increasing productivity and reducing processing costs, and of creating new products or variants of existing ones. Fashion, in the widest sense of the word mean fulfillment of consumer demands, through the ages constitutes a fundamental and conditional element for the whole textile industry. Fancy yarns present deliberate, decorative continuous or programmed effects of colour and/or form they are used to create some variation in the aesthetic appearance of a fabric. The drafting process is deliberately interrupted through the effect yarn device to produce slubs in the final yarn. The present research study was aimed to evaluate the quality characteristics of slub fancy yarn by changing slub length, inter slub distance, slub thickness and twist multiplier (T.M) at ring and compact spinning systems. (author)

  9. Liquid ring vacuum pumps, compressors and systems conventional and hermetic design

    CERN Document Server

    Bannwarth, Helmut

    2006-01-01

    Based on the very successful German editions, this English version has been thoroughly updated and revised to reflect the developments of the last years and the latest innovations in the field.Throughout, the author makes excellent use of real-life examples and highly praised didactics to disseminate his expert knowledge needed by vacuum technology users and engineers in their daily work at industrial plants, as consultants or in design offices. He covers in detail the most modern liquid ring pumps, with chapters dedicated to maintenance, explosion prevention and general procedures for saf

  10. Simulations of the low-dimensional molecular-based spin systems: dodecanuclear nickel ring

    International Nuclear Information System (INIS)

    Kamieniarz, G.; Haglauer, M.; Caramico D'Auria, A.; Esposito, F.; Gatteschi, D.

    2005-01-01

    The numerical exact diagonalization technique exploiting the point-group symmetry is worked out for the anisotropic Heisenberg spin Hamiltonian with the ring geometry. It is applied in large-scale simulations to the supramolecule Ni 12 (O 2 CMe) 12 (chp) 12 (H 2 O) 6 (THF) 6 , yielding the low-level energy spectra as a function of the single-ion anisotropy D and the thermodynamic functions. The strength of the constant D is analysed and estimated at D/k B =1.5K. The results for the zero-field susceptibility and the field-dependent magnetization are presented and compared with experimental data

  11. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

    Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

    2018-03-01

    The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

  12. Donor impurity states and related optical response in a lateral coupled dot-ring system under applied electric field

    Energy Technology Data Exchange (ETDEWEB)

    Correa, J.D. [Departamento de Ciencias Básicas, Universidad de Medellín, Medellín (Colombia); Mora-Ramos, M.E. [Centro de Investigación en Ciencias, Instituto de Ciencias Básicas y Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2015-09-01

    A study on the effects of an externally applied electric field on the linear optical absorption and relative refractive index change associated with transitions between off-center donor impurity states in laterally coupled quantum dot-ring system is reported. Electron states are calculated within the effective mass and parabolic band approximations by means of an exact diagonalization procedure. The states and the optical response in each case show significant sensitivity to the geometrical distribution of confining energies as well as to the strength of the applied field.

  13. Donor impurity states and related optical response in a lateral coupled dot-ring system under applied electric field

    International Nuclear Information System (INIS)

    Correa, J.D.; Mora-Ramos, M.E.; Duque, C.A.

    2015-01-01

    A study on the effects of an externally applied electric field on the linear optical absorption and relative refractive index change associated with transitions between off-center donor impurity states in laterally coupled quantum dot-ring system is reported. Electron states are calculated within the effective mass and parabolic band approximations by means of an exact diagonalization procedure. The states and the optical response in each case show significant sensitivity to the geometrical distribution of confining energies as well as to the strength of the applied field

  14. Ring opening of 2-aza-3-borabicyclo[2.2.0]hex-5-ene, the Dewar form of 1,2-dihydro-1,2-azaborine: stepwise versus concerted mechanisms

    Directory of Open Access Journals (Sweden)

    Holger F. Bettinger

    2013-04-01

    Full Text Available The ring opening of the Dewar form of 1,2-dihydro-1,2-azaborine, 2-aza-3-borabicyclo[2.2.0]hex-5-ene (3 is investigated by theoretical methods by using multiconfiguration SCF (CASSCF and coupled cluster theory [CCSD(T] with basis sets up to polarised quadruple-zeta quality. The title compound was previously reported to form photochemically in cryogenic noble gas matrices from 1,2-dihydro-1,2-azaborine (4. Four reaction paths for the thermal ring opening of 3 to 4 could be identified. These are the conventional disrotatory and conrotatory electrocyclic ring-opening pathways where the BN unit is only a bystander. Two more favourable paths are stepwise and involve 1,3-boron–carbon interactions. The lowest energy barrier for the isomerisation reaction, 22 kcal mol−1, should be high enough for an experimental observation in solution. However, in solution the dimerisation of 3 is computed to have a very low barrier (3 kcal mol−1, and thus 3 is expected to be a short-lived reactive intermediate.

  15. Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

    International Nuclear Information System (INIS)

    Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

    2012-01-01

    It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

  16. Design of a power amplifier for the LAMPF proton storage ring transverse damper system

    International Nuclear Information System (INIS)

    Lunsford, J.S.

    1981-01-01

    A power amplifier has been designed to drive the 50-Ω stripline deflection structures in the transverse active damper of the Los Alamos 800-MeV Proton Storage Ring (PSR). The unit will provide 600-V peak-to-peak with a dc-to-100-MHz bandwidth. Other important characteristics include < 40-ns delay time, 50-dB voltage gain, and 4-ns risetime with < 5% overshoot and ringing. Because of the current-drive properties of the amplifier, two amplifiers could be combined to provide over 1000-V peak-to-peak into 50 Ω, with very little bandwidth degradation. Components in the power amplifier that represent new designs are a 20-tube distributed-amplifier output stage; a driver stage, using VMOS FET and bipolar transistors; a high-voltage probe, with good dc stability and 150-MHz bandwidth; a transient suppressor circuit, using PIN diodes to protect the transistorized drivers from tube arcing; a nonlinear amplifier to compensate for the nonlinear characteristics of the distributed amplifier; and a first-fail indicator circuit to aid in locating the prime causes of equipment failures

  17. Performance of a high sensitivity time-of-flight PET ring operating simultaneously within a 3T MR system

    International Nuclear Information System (INIS)

    Levin, Craig S; Jansen, Floris; Deller, Tim; Maramraju, Sri Harsha; Grant, Alex; Iagaru, Andrei

    2014-01-01

    A time-of-flight (TOF)-PET/MR research system installed at Stanford will be used to test the hypotheses that (a) it is possible to acquire simultaneous TOF-PET and 3T MR data while achieving uncompromised performance in both modalities and (b) simultaneous TOF-PET/MR is a tool for multi-parameter characterization of disease. In this paper we will describe the design as well as performance measurements both for the standalone PET ring, and with the two systems integrated. We will also show a selection of clinical images to compare the performance of the integrated TOF-PET/MR system with that of a state-of-the-art PET/CT system.

  18. Toward a noninvasive automatic seizure control system in rats with transcranial focal stimulations via tripolar concentric ring electrodes.

    Science.gov (United States)

    Makeyev, Oleksandr; Liu, Xiang; Luna-Munguía, Hiram; Rogel-Salazar, Gabriela; Mucio-Ramirez, Samuel; Liu, Yuhong; Sun, Yan L; Kay, Steven M; Besio, Walter G

    2012-07-01

    Epilepsy affects approximately 1% of the world population. Antiepileptic drugs are ineffective in approximately 30% of patients and have side effects. We are developing a noninvasive, or minimally invasive, transcranial focal electrical stimulation system through our novel tripolar concentric ring electrodes to control seizures. In this study, we demonstrate feasibility of an automatic seizure control system in rats with pentylenetetrazole-induced seizures through single and multiple stimulations. These stimulations are automatically triggered by a real-time electrographic seizure activity detector based on a disjunctive combination of detections from a cumulative sum algorithm and a generalized likelihood ratio test. An average seizure onset detection accuracy of 76.14% was obtained for the test set (n = 13). Detection of electrographic seizure activity was accomplished in advance of the early behavioral seizure activity in 76.92% of the cases. Automatically triggered stimulation significantly (p = 0.001) reduced the electrographic seizure activity power in the once stimulated group compared to controls in 70% of the cases. To the best of our knowledge this is the first closed-loop automatic seizure control system based on noninvasive electrical brain stimulation using tripolar concentric ring electrode electrographic seizure activity as feedback.

  19. Structure and dynamics of ringed galaxies

    International Nuclear Information System (INIS)

    Buta, R.J.

    1984-01-01

    In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals

  20. Comparing the predictive value of the pelvic ring injury classification systems by Tile and by Young and Burgess.

    Science.gov (United States)

    Osterhoff, Georg; Scheyerer, Max J; Fritz, Yannick; Bouaicha, Samy; Wanner, Guido A; Simmen, Hans-Peter; Werner, Clément M L

    2014-04-01

    Radiology-based classifications of pelvic ring injuries and their relevance for the prognosis of morbidity and mortality are disputed in the literature. The purpose of this study was to evaluate potential differences between the pelvic ring injury classification systems by Tile and by Young and Burgess with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries. Two-hundred-and-eighty-five consecutive patients with pelvic ring fractures were analyzed for mortality within 30 days after admission, number of blood units and total volume of fluid infused during the first 24h after trauma, the Abbreviated Injury Severity (AIS) scores for head, chest, spine, abdomen and extremities as a function of the Tile and the Young-Burgess classifications. There was no significant relationship between occurrence of death and fracture pattern but a significant relationship between fracture pattern and need for blood units/total fluid volume for Tile (p<.001/p<.001) and Young-Burgess (p<.001/p<.001). In both classifications, open book fractures were associated with more fluid requirement and more severe injuries of the abdomen, spine and extremities (p<.05). When divided into the larger subgroups "partially stable" and "unstable", unstable fractures were associated with a higher mortality rate in the Young-Burgess system (p=.036). In both classifications, patients with unstable fractures required significantly more blood transfusions (p<.001) and total fluid infusion (p<.001) and higher AIS scores. In this first direct comparison of both classifications, we found no clinical relevant differences with regard to their predictive value on mortality, transfusion/infusion requirement and concomitant injuries. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Energy of Intramolecular Hydrogen Bonding in ortho-Hydroxybenzaldehydes, Phenones and Quinones. Transfer of Aromaticity from ipso-Benzene Ring to the Enol System(s

    Directory of Open Access Journals (Sweden)

    Danuta Rusinska-Roszak

    2017-03-01

    Full Text Available Intramolecular hydrogen bonding (HB is one of the most studied noncovalent interactions of molecules. Many physical, spectral, and topological properties of compounds are under the influence of HB, and there are many parameters used to notice and to describe these changes. Hitherto, no general method of measurement of the energy of intramolecular hydrogen bond (EHB has been put into effect. We propose the molecular tailoring approach (MTA for EHB calculation, modified to apply it to Ar-O-H∙∙∙O=C systems. The method, based on quantum calculations, was checked earlier for hydroxycarbonyl-saturated compounds, and for structures with resonance-assisted hydrogen bonding (RAHB. For phenolic compounds, the accuracy, repeatability, and applicability of the method is now confirmed for nearly 140 structures. For each structure its aromaticity HOMA indices were calculated for the central (ipso ring and for the quasiaromatic rings given by intramolecular HB. The comparison of calculated HB energies and values of estimated aromaticity indices allowed us to observe, in some substituted phenols and quinones, the phenomenon of transfer of aromaticity from the ipso-ring to the H-bonded ring via the effect of electron delocalization.

  2. Wake patterns behind boulders in the rings of Saturn

    International Nuclear Information System (INIS)

    Brattli, A.; Havnes, O.; Melandsoe, F.

    2002-01-01

    The flow of charged dust around an electrically charged boulder moving through an environment thought to be typical of planatery rings is studied. As the boulder moves through the ring dust it will excite a V-shaped Mach cone pattern of a form and complexity which varies significantly with boulder size, relative velocity between the boulder and the dust, and with dust plasma conditions. Parameters relevant to the Saturnian ring system are used to compute examples which demonstrate the change in Mach cone patterns with the relevant parameters. Shortcomings of the model are discussed and ways to improve the calculations of Mach cone patterns are pointed out

  3. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  4. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  5. Design and monitoring of photostability systems for amlodipine dosage forms.

    Science.gov (United States)

    Ragno, G; Cione, E; Garofalo, A; Genchi, G; Ioele, G; Risoli, A; Spagnoletta, A

    2003-10-20

    Photostability of amlodipine (AML) has been monitored in several pharmaceutical inclusion systems characterized by plurimolecular aggregation of the drug and excipients with high molecular weight. Several formulations including cyclodextrins, liposomes and microspheres have been prepared and characterized. The photodegradation process has been monitored according to the conditions suggested by the ICH Guideline for photostability testing, by using a light cabinet equipped with a Xenon lamp and monitored by spectrophotometry. The formulations herein tested have been found to be able to considerably increase drug stability, when compared with usual pharmaceutical forms. The residual concentration detected in the inclusion complexes with cyclodextrins and liposomes was 90 and 77%, respectively, while a very good value of 97% was found for microspheres, after a radiant exposure of 11,340 kJm(-2).

  6. A STUDY ON THE DEGRADATION MECHANISM OF PHOTOCROSSLINKING PRODUCTS FORMED BY CYCLIZED POLYISOPRENE-DIAZIDE SYSTEM UNDER THE INFLUENCE OF ALKYL BENZENE SULFONIC ACIDS

    Institute of Scientific and Technical Information of China (English)

    HUANG Junlian; SUN Meng

    1989-01-01

    The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects ofalkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.

  7. Simulations of the low-dimensional molecular-based spin systems: dodecanuclear nickel ring

    Energy Technology Data Exchange (ETDEWEB)

    Kamieniarz, G. [Computational Physics Division, Institute of Physics, A. Mickiewicz University, ul. Umultowska 85, Poznan 61-614 (Poland)]. E-mail: gjk@amu.edu.pl; Haglauer, M. [Computational Physics Division, Institute of Physics, A. Mickiewicz University, ul. Umultowska 85, Poznan 61-614 (Poland); Caramico D' Auria, A. [Dipartimento di Scienze Fisiche, Universita di Napoli, Naples (Italy) and INFM Unita di Naples (Italy); Esposito, F. [Dipartimento di Scienze Fisiche, Universita di Napoli, Naples (Italy) and INFM Unita di Naples (Italy); Gatteschi, D. [Dipartimento di Chimica, Universita di Firenze, Sesto Fiorentino (Italy)

    2005-04-15

    The numerical exact diagonalization technique exploiting the point-group symmetry is worked out for the anisotropic Heisenberg spin Hamiltonian with the ring geometry. It is applied in large-scale simulations to the supramolecule Ni{sub 12}(O{sub 2}CMe){sub 12}(chp){sub 12}(H{sub 2}O){sub 6}(THF){sub 6}, yielding the low-level energy spectra as a function of the single-ion anisotropy D and the thermodynamic functions. The strength of the constant D is analysed and estimated at D/k{sub B}=1.5K. The results for the zero-field susceptibility and the field-dependent magnetization are presented and compared with experimental data.

  8. Positron ring system using Anger-type detectors. Progress report for period ending December 31, 1984

    International Nuclear Information System (INIS)

    Muehllehner, G.

    1984-08-01

    A single-ring positron camera consisting of six position-sensitive single-crystal detectors has been constructed, and its performance has been evaluated for a variety of applications. The major factors limiting its performance have been established, and methods to overcome some of these limitations have been explored. At low data rates, a spatial resolution of 6.5 mm full-width-half-maximum (FWHM) has been measured in the final reconstructed image, and at high data rates a spatial resolution below 8 mm FWHM has been achieved. Initial problems in imaging extended objects have been overcome through careful normalization of the data and by using an iterative reconstruction algorithm which is insensitive to the missing data due to the gaps between the detectors. 10 figures

  9. UHV seal studies for the advanced photon source storage ring vacuum system

    International Nuclear Information System (INIS)

    Gonczy, J.D.; Ferry, R.J.; Niemann, R.C.; Roop, B.

    1991-01-01

    The Advanced Photon Source (APS) Storage Ring Vacuum Chambers (SRVC) are constructed of aluminum. The chamber design incorporates aluminum alloy 2219-T87 Conflat flanges welded to an aluminum alloy 6063-T5 extruded chamber body. Vacuum connections to the aluminum Conflat chamber flanges are by means of 304 stainless steel Conflat flanges. To evaluate the Conflat seal assemblies relative to vacuum bake cycles, a Conflat Bake Test Assembly (CBTA) was constructed, and thermal cycling tests were performed between room temperature and 150 degrees C on both stainless steel to aluminum Conflat assemblies and aluminum to aluminum Conflat assemblies. A Helicoflex Bake Test Assembly (HBTA) was similarly constructed to evaluate Helicoflex seals. Both Conflat and Helicoflex seals were studied in a SRVC Sector String Test arrangement of five SRVC sections. The CBTA, HBTA and SRVC tests and their results are reported. 3 refs., 2 figs., 2 tabs

  10. A ring test of a wireless in vitro gas production system

    DEFF Research Database (Denmark)

    Cornou, Cecile; Storm, Ida Marie Lindhardt Drejer; Hindrichsen, Ida Katarina Auf der M.

    2013-01-01

    ) or sheep (SP). Curves, corrected for blanks, were fitted using an exponential regression model with a lag time. The following variables were considered: (i) GP24 and GP48: raw values at 24 and 48 h (mL/g DM), corrected for blanks; (ii) A: asymptotic GP (mL/g DM); (iii) T1/2: time when half A is produced (h......); (iv) GPMR: maximum predicted GP rate (mL/h); (v) L: lag time (h). A mixed model including laboratories as random effect was used. A significant interaction between substrate and laboratories was found for all variables except A. The most repeatable and reproducible results were observed for A and GP48......The in vitro gas production (GP) technique has been widely used for feed evaluation. However, variability in results limits useful comparisons. Results from a ring test undertaken in four laboratories (Italy - IT, Spain - SP, Wales - WA and Denmark - DK) using the same wireless equipment (ANKOM...

  11. Space-Time Convolutional Codes over Finite Fields and Rings for Systems with Large Diversity Order

    Directory of Open Access Journals (Sweden)

    B. F. Uchôa-Filho

    2008-06-01

    Full Text Available We propose a convolutional encoder over the finite ring of integers modulo pk,ℤpk, where p is a prime number and k is any positive integer, to generate a space-time convolutional code (STCC. Under this structure, we prove three properties related to the generator matrix of the convolutional code that can be used to simplify the code search procedure for STCCs over ℤpk. Some STCCs of large diversity order (≥4 designed under the trace criterion for n=2,3, and 4 transmit antennas are presented for various PSK signal constellations.

  12. A pneumatic transfer system for special form 252Cf

    International Nuclear Information System (INIS)

    Gehrke, R.J.; Berry, S.M.; Grafwallner, E.G.; Hoggan, J.M.

    1996-09-01

    A pneumatic transfer system has been developed for use with series 100 Special Form 252 Cf. It was developed to reduce the exposure to personnel handling sources of 252 Cf with masses up to 150 microg by permitting remotely activated two-way transfer between the storage container and the irradiation position. The pneumatic transfer system also permits transfers for reproducible repetitive irradiation periods. In addition to the storage container equipped with quick-release fittings, the transfer system consists of an irradiation station, a control box with momentary contact switches to activate the air-pressure control valves and indicators to identify the location of the source, and connecting air hose and electrical wire. A source of 20 psig air and 110 volt electrical power are required for operation of the transfer system which can be easily moved and set up by one individual in 5 to 10 minutes. Tests have shown that rarely does a source become lodged in the transfer tubing, but two methods have been developed to handle incomplete transfers of the 252 Cf source. The first method consists of closing one air vent to allow a pressure impulse to propel the source to the opposite side. The second method applies to those 252 Cf capsules with a threaded or tapped end to which a small ferromagnetic piece can be attached; an incompletely transferred source in the transfer tube can then be guided to a position of safety by surrounding the transfer tubing containing the capsule with a horseshoe magnet attached to the end of a long pole

  13. Response dependence of a ring ionization chamber response on the size of the X radiation field

    International Nuclear Information System (INIS)

    Yoshizumi, Maira T.; Caldas, Linda V.E.

    2009-01-01

    A ring monitor ionization chamber was developed at the IPEN-Sao Paulo, Brazil, fixed on a system of collimators which determine the dimension of the radiation field size. This work verified that the ring chamber response depends on the exponential form with the size of de radiation field

  14. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  15. Spin dynamics in mesoscopic size magnetic systems: A 1HNMR study in rings of iron (III) ions

    International Nuclear Information System (INIS)

    Lascialfari, A.; Gatteschi, D.; Borsa, F.; Cornia, A.

    1997-01-01

    Two magnetic molecular clusters containing almost coplanar rings of iron (III) ions with spinS=5/2 have been investigated by 1 H NMR and relaxation measurements. The first system, which will be referred to as Fe6, is a molecule of general formula [NaFe 6 (OCH 3 ) 12 (C 17 O 4 H 15 ) 6 ] + ClO 4 - or [NaFe 6 (OCH 3 ) 12 (C 15 H 11 O 2 ) 6 ] + ClO 4 - or [LiFe 6 (OCH 3 ) 12 (C 15 H 11 O 2 ) 6 ] + ClO 4 - while the second type of ring, denoted Fe10, corresponds to the molecule [Fe 10 (OCH 3 ) 20 (C 2 H 2 O 2 Cl) 10 ]. The 1 H NMR linewidth is broadened by the nuclear dipolar interaction and by the dipolar coupling of the protons with the iron (III) paramagnetic moment. It is found that the nuclear spin-lattice relaxation rate, T 1 -1 , of the proton is a sensitive probe of the Fe spin dynamics. In both clusters, T 1 -1 decreases with decreasing temperatures from room temperature, goes through a peak just below about 30 K in Fe6 and 10 K in Fe10, and it drops exponentially to very small values at helium temperature. The temperature dependence of the relaxation rate is discussed in terms of the fluctuations of the local spins within the allowed total spin configurations in the framework of the weak collision theory to describe the nuclear relaxation. We use the calculated energy levels for the Fe6 ring based on a Heisenberg Hamiltonian and the value of J obtained from the fit of the magnetic susceptibility to describe semiquantitatively the behavior of T 1 -1 vs T. The exponential drop of T 1 -1 at low temperature is consistent with a nonmagnetic singlet ground state separated by an energy gap from the first excited triplet state. (Abstract Truncated)

  16. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  17. A high energy photon detector system in compact form

    International Nuclear Information System (INIS)

    Kato, Sadayuki; Sugano, Katsuhito; Yoshioka, Masakazu.

    1975-01-01

    The development of a high energy photon detector system in compact form for use in experiments of high energy physics is described, and the results of its characteristics calibrated using converted electron beams and a pair spectrometer are reported. This system consists of a total absorption lead glass Cerenkov counter, twenty hodoscope arrays for the vertical and the horizontal directions respectively, a lead plate for the conversion of γ-rays into electron-positron pairs, veto counters, photon hardener, and lead blocks for shieldings and collimation. The spatial resolution of the hodoscope is 15 mm for each direction, covering 301 x 301 mm 2 area. The energy resolution of the total absorption lead glass Cerenkov counter, whose volume is 30 x 30 x 30 cm 3 , is typically 18 % (FWHM) for the incident electron energy of 500 MeV, and it can be expressed with a relation of ΔE/E = 3.94 Esup(-1/2). (E in MeV). (auth.)

  18. Integrable couplings of relativistic Toda lattice systems in polynomial form and rational form, their hierarchies and bi-Hamiltonian structures

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xixiang [College of Science, Shandong University of Science and Technology, Qingdao 266510 (China)], E-mail: xixiang_xu@yahoo.com.cn

    2009-10-02

    Integrable couplings of relativistic Toda lattice systems in polynomial form and rational form, and their hierarchies, are derived from a four-by-four discrete matrix eigenvalue problem. The bi-Hamiltonian structure for every integrable coupling in the two hierarchies obtained is established by means of the discrete variational identity. Ultimately, Liouvolle integrability of the obtained integrable couplings is demonstrated.

  19. Further explorations of cosmogonic shadow effects in the Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.; Axnaes, I.; Brenning, N.; Lindqvist, P.A.

    1985-01-01

    The mass distribution in the Saturnian ring system is investigated and compared with predictions from the cosmogonic theory by Alfven and Arrhenius. According to this theory, the matter in the rings has once been in the form of a magnetized plasma, in which the gravitation is balanced partly by the centrifugal force and partly by the magnetic field. As the plasma is neutralized, the magnetic force disappears and the matter can be shown to fall in to a distance 2/3 of the original. This gives cause to the so called 'cosmogonic shadow effect', which has been demonstrated earlier for the astroidal belt and in the large scale structure of the Saturnian ring system. The relevance of the cosmogonic shadow effect is investigated for parts of the finer structures of the Saturnian ring system. It is shown that many structures of the present ring system can be understood as shadows and antishadows of cosmogonic origin. These appear in the form of double rings centered around a position a factor 0.64 (slightly less than 2/3) closer to Saturn than the causing feature. (author)

  20. A low-frequency high-voltage rf-barrier-bunching system for high-intensity neutron source compressor rings

    International Nuclear Information System (INIS)

    Hardek, T.W.; Ziomek, C.; Rees, D.

    1995-01-01

    A Los Alamos design for a 1-MW pulsed neutron source incorporates a ring utilizing an rf-barrier bunching system. This bunching concept allows uniform longitudinal beam distributions with low momentum spread. Bunching cavities are operated at the revolution frequency (1.5 MHz in this case) and each of the 2nd, 3rd, 4th, and 5th revolution frequency harmonics. Their effects combine to maintain a beam free gap in the longitudinal distribution of the accumulated beam. The cavities are driven by low-plate-resistance common-cathode configured retrode amplifiers incorporating local rf feedback. Additional adaptive feed-forward hardware is included to reduce the beam-induced bunching-gap voltages well below that achievable solely with rf feedback. Details of this system are presented along with a discussion of the various feed-back and feed-forward techniques incorporated

  1. Slow light based on plasmon-induced transparency in dual-ring resonator-coupled MDM waveguide system

    International Nuclear Information System (INIS)

    Zhan, Shiping; Li, Hongjian; He, Zhihui; Li, Boxun; Yang, Hui; Cao, Guangtao

    2014-01-01

    We report a theoretical and numerical investigation of the plasmon-induced transparency (PIT) effect in a dual-ring resonator-coupled metal–dielectric–metal waveguide system. A transfer matrix method (TMM) is introduced to analyse the transmission and dispersion properties in the transparency window. A tunable PIT is realized in a constant separation design. The phase dispersion and slow-light effect are discussed in both the resonance and non-resonance conditions. Finally, a propagation constant based on the TMM is derived for the periodic system. It is found that the group index in the transparency window of the proposed structure can be easily tuned by the period p, which provides a new understanding, and a group index ∼51 is achieved. The quality factor of resonators can also be effective in adjusting the dispersion relation. These observations could be helpful to fundamental research and applications for integrated plasmonic devices. (paper)

  2. In-situ calibration: migrating control system IP module calibration from the bench to the storage ring

    International Nuclear Information System (INIS)

    Weber, Jonah M.; Chin, Michael

    2002-01-01

    The Control System for the Advanced Light Source (ALS) at Lawrence Berkeley National Lab (LBNL) uses in-house designed IndustryPack(registered trademark) (IP) modules contained in compact PCI (cPCI) crates with 16-bit analog I/O to control instrumentation. To make the IP modules interchangeable, each module is calibrated for gain and offset compensation. We initially developed a method of verifying and calibrating the IP modules in a lab bench test environment using a PC with LabVIEW. The subsequent discovery that the ADCs have significant drift characteristics over periods of days of installed operation prompted development of an ''in-situ'' calibration process--one in which the IP modules can be calibrated without removing them from the cPCI crates in the storage ring. This paper discusses the original LabVIEW PC calibration and the migration to the proposed in-situ EPICS control system calibration

  3. Experimental investigation of thermal processes in the multi-ring Couette system with counter rotation of cylinders

    Science.gov (United States)

    Mamonov, V. N.; Nazarov, A. D.; Serov, A. F.; Terekhov, V. I.

    2016-01-01

    The effect of parameters of the multi-ring Couette system with counter rotating coaxial cylinders on the process of thermal energy release in a viscous liquid filling this system is considered with regard to the problem of determining the possibility of creating the high-performance wind heat generator. The multi-cylinder rotor design allows directly conversion of the mechanical power of a device consisting of two "rotor" wind turbines with a common axis normal to the air flow into the thermal energy in a wide range of rotational speed of the cylinders. Experimental results on the measurement of thermal power released in the pilot heat generator at different relative angular speeds of cylinder rotation are presented.

  4. A mechanical mechanism for translocation of ring-shaped helicases on DNA and its demonstration in a macroscopic simulation system

    Science.gov (United States)

    Chou, Y. C.

    2018-04-01

    The asymmetry in the two-layered ring structure of helicases and the random thermal fluctuations of the helicase and DNA molecules are considered as the bases for the generation of the force required for translocation of the ring-shaped helicase on DNA. The helicase comprises a channel at its center with two unequal ends, through which strands of DNA can pass. The random collisions between the portion of the DNA strand in the central channel and the wall of the channel generate an impulsive force toward the small end. This impulsive force is the starting point for the helicase to translocate along the DNA with the small end in front. Such a physical mechanism may serve as a complementary for the chemomechanical mechanism of the translocation of helicase on DNA. When the helicase arrives at the junction of ssDNA and dsDNA (a fork), the collision between the helicase and the closest base pair may produce a sufficient impulsive force to break the weak hydrogen bond of the base pair. Thus, the helicase may advance and repeat the process of unwinding the dsDNA strand. This mechanism was tested in a macroscopic simulation system where the helicase was simulated using a truncated-cone structure and DNA was simulated with bead chains. Many features of translocation and unwinding such as translocation on ssDNA and dsDNA, unwinding of dsDNA, rewinding, strand switching, and Holliday junction resolution were reproduced.

  5. Conformational Effects through Hydrogen Bonding in a Constrained γ-Peptide Template: From Intraresidue Seven-Membered Rings to a Gel-Forming Sheet Structure.

    Science.gov (United States)

    Awada, Hawraà; Grison, Claire M; Charnay-Pouget, Florence; Baltaze, Jean-Pierre; Brisset, François; Guillot, Régis; Robin, Sylvie; Hachem, Ali; Jaber, Nada; Naoufal, Daoud; Yazbeck, Ogaritte; Aitken, David J

    2017-05-05

    A series of three short oligomers (di-, tri-, and tetramers) of cis-2-(aminomethyl)cyclobutane carboxylic acid, a γ-amino acid featuring a cyclobutane ring constraint, were prepared, and their conformational behavior was examined spectroscopically and by molecular modeling. In dilute solutions, these peptides showed a number of low-energy conformers, including ribbonlike structures pleated around a rarely observed series of intramolecular seven-membered hydrogen bonds. In more concentrated solutions, these interactions defer to an organized supramolecular assembly, leading to thermoreversible organogel formation notably for the tripeptide, which produced fibrillar xerogels. In the solid state, the dipeptide adopted a fully extended conformation featuring a one-dimensional network of intermolecularly H-bonded molecules stacked in an antiparallel sheet alignment. This work provides unique insight into the interplay between inter- and intramolecular H-bonded conformer topologies for the same peptide template.

  6. Nature-aligned approaches to form students’ system motivation

    Directory of Open Access Journals (Sweden)

    Marina V. Ulyanova

    2017-01-01

    -affirmation, independence, self-efficacy, self-leadership, and self-government are initiated and realized. Only the system model of motivation, organized in such a way, forms life potential of personality in the process of education,  beginning with primary school and until post-graduate education, that is able to ensure good health and satisfy one’s vanity, without which he/she will not feel happy and assist sustainable development of the society on the whole. Only observing laws of harmony in the educational process provides formation of personalities with a high level of harmony that will determine the level of harmony in the society, as well. The philosophical, managerial, psychological and pedagogical aspects of individual self-perfection processes are considered in the paper. Special attention is paid to the questions of forming common educational abilities and skills in the process of teaching academic disciplines according to the nature-aligned methodology. The key mechanisms of object-subject transformation in the process of education are described, that provide an individual with energy for passing to the next level of his/her personality development. It is shown how nature-aligned methodology of noospheric pedagogics enables to make the process of the student’s personality growth self-regulated in the process of education.   

  7. Pediatric Scleroderma –Systemic and Localized Forms

    Science.gov (United States)

    Torok, Kathryn S.

    2012-01-01

    Synopsis statement Pediatric scleroderma includes two major groups of clinical entities, systemic sclerosis (SSc) and localized scleroderma (LS). Although both share a common pathophysiology, with an initial inflammatory phase associated with endothelial activation, and a later fibrotic phase evidenced by collagenization of tissue and appreciable skin thickness, their clinical manifestations differ. LS is typically confined to the skin and underlying subcutis, and though not fatal like SSc, up to a quarter of the patients may have extracutaneous disease manifestations, such as arthritis and uveitis. While any organ may be affected in SSc, vascular (Raynaud’s phenomenon), cutaneous (skin thickening), GI, pulmonary and musculoskeletal involvement are most commonly seen in children. Auto-antibody profiles in childhood onset SSc can assist in predicting internal organ involvement. Treatment for both forms of scleroderma targets the active inflammatory stage and halts disease progression; however, progress still needs to be made towards the development of a more effective anti-fibrotic therapy to help reverse disease damage. PMID:22560576

  8. Superconducting quantum interference device microscopy of fluxoids in superconducting rings and artificially layered systems

    International Nuclear Information System (INIS)

    Kirtley, J R; Tsuei, C C; Tafuri, F; Medaglia, P G; Orgiani, P; Balestrino, G

    2004-01-01

    The SQUID microscope has the advantages of excellent field sensitivity, small interaction between the sensor and the sample, and a linear, easily calibrated response. It has the disadvantages of modest spatial resolution and the requirement of a cooled sensor. In this paper we will present results from two applications of the SQUID microscope, chosen with these advantages and disadvantages in mind. First, we have found that the distribution of final fluxoid states of quenched superconducting rings can be accounted for by using a mechanism of the freeze-out of thermally activated fluxoids. This mechanism is complementary to one proposed by Kibble and Zurek in connection with tests of models of the generation of topological singularities in the early development of the universe, and which relies only on causality to produce a freeze-out of the order of parameter fluctuations. Second, we have studied Pearl vortices in [BaCuO x ] n /[CaCuO 2 ] m (CBCO) artificial superlattice structures, with as few as three superconducting CuO 2 layers. The Pearl penetration depths of vortices trapped in these films, which should be inversely proportional to the areal superfluid density, are very long (up to ∼1 mm), as expected. In both cases it would be difficult to image fluxoids that generate such weak magnetic fields using any other technique

  9. Rectangular Ring Antenna Excited by Circular Disc Monopole for WiMAX System

    Directory of Open Access Journals (Sweden)

    Souphanna Vongsack

    2014-01-01

    Full Text Available This research presents a rectangular ring antenna excited by a circular disc monopole (CDM mounted in front of a square reflector. The proposed antenna is designed to cover a frequency range of 2.300–5.825 GHz and thereby is suitable for WiMAX applications. Multiple parametric studies were carried out using the CST Microwave Studio simulation program. A prototype antenna was fabricated and experimented. The measurements were taken and compared with the simulation results, which indicates good agreement between both results. The prototype antenna produces an impedance bandwidth (|S11| < −10 dB that covers the WiMAX frequency range and a constant unidirectional radiation pattern (θ=0° and ∅=90°. The minimum and maximum gains are 3.7 and 8.7 dBi, respectively. The proposed antenna is of compact size and has good unidirectional radiation performance. Thus, it is very suitable for a multitude of WiMAX applications.

  10. Magnetoconductance fluctuations in a strongly correlated disordered ring system at low temperatures

    International Nuclear Information System (INIS)

    Chen, H.; Ishihara, M.; Li, Z.; Kawazoe, Y.

    1996-01-01

    Using a recursive real-space Green close-quote s-function technique in the tight-binding model, we study the influence of the electron-electron Hubbard interaction on the magnetoconductance fluctuations in a disordered ring at low temperatures. Our numerical results improve the previous theoretical predictions for the magnetoconductance fluctuations as a function of magnetic flux compared with experiments. Meanwhile, we find several anomalous phenomena at low temperatures, which do not survive at high temperatures. For the Fermi level E f =0.1t (t is the hopping integral) the envelope of magnetoconductance fluctuations drops to a lower value at some magnetic flux, while the Hubbard interaction causes the drop to occur at larger flux. The magnetoconductance fluctuations vary with the Hubbard interaction for magnetic flux around 20Φ 0 (Φ 0 =hc/e) mainly in the range of small U. The Hubbard interaction narrows the widths of the main peaks in the Fourier spectrum, but it does not change their positions. copyright 1996 The American Physical Society

  11. How systems form and how systems break a beginner’s guide for studying the world

    CERN Document Server

    Ren, Chiang H

    2017-01-01

    Our world is composed of systems within systems—the machines we build, the information we share, the organizations we form, and elements of nature that surround us. Therefore, nearly every field of study and practice embodies behaviors stemming from system dynamics. Yet the study of systems has remained somewhat fragmented based on philosophies, methodologies, and intentions. Many methodologies for analyzing complex systems extend far beyond the traditional framework of deduction evaluation and may, thus, appear mysterious to the uninitiated. This book seeks to dispel the mysteries of systems analysis by holistically explaining the philosophies, methodologies, and intentions in the context of understanding how all types of systems in our world form and how these systems break. This presentation is made at the level of conceptual understanding, with plenty of figures but no mathematical formulas, for the beginning student and interested readers new to studying systems. Through the conceptual understanding pr...

  12. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

    Buchhave, Preben; Abitan, Haim; Tidemand-Lichtenberg, Peter

    2000-01-01

    Variable phase coupling to an external ring is used to control a unidirectional ring laser. The observed behavior of the coupled rings is explained theoretically. We have found experimentally that by quickly changing the phase of the feedback from the external ring it is possible to Q......-switch the ring laser. Also, at certain values of the phase of the feedback in the external ring, instabilities in the total system occur and oscillations arise in the ring laser....

  13. Completeness of the ring of polynomials

    DEFF Research Database (Denmark)

    Thorup, Anders

    2015-01-01

    Consider the polynomial ring R:=k[X1,…,Xn]R:=k[X1,…,Xn] in n≥2n≥2 variables over an uncountable field k. We prove that R   is complete in its adic topology, that is, the translation invariant topology in which the non-zero ideals form a fundamental system of neighborhoods of 0. In addition we pro...

  14. Magnetization of two coupled rings

    International Nuclear Information System (INIS)

    Avishai, Y; Luck, J M

    2009-01-01

    We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum

  15. Vacuum injection system for hydrogen micro-spheres in the CELSIUS storage ring

    International Nuclear Information System (INIS)

    Tinoco, Hernan.

    1990-01-01

    The use of hydrogen micro-spheres as internal targets in the CELSIUS storage ring has been proposed for light meson rare decay measurements. The target generation apparatus design is based on that developed for refueling of fusion tokamak reactors. The micro-spheres are produced by acoustic excitation of a liquid hydrogen jet, and are injected into vacuum for the experiments by means of a hydrogen gas flow through an injection nozzle. The work reported here is an analysis of the gas flow in the injection nozzle, of the entrained motion of the micro-spheres considered as spherical particles, and of the heat transfer between them and the gas. The computation of the heat transfer allows the determination of the conditions under which the evaporation of the micro-spheres is negligible. It is shown that the gas must be cooled to temperatures near that of the micro-spheres for these to survive. Together with the computation of the gas flow and particle motion, the analysis includes the design of the injection nozzle. The requirements of well defined mass flow rate and low perturbation level suggest a nozzle consisting of a contraction region and a straight region with constant cross-sectional area. This nozzle is to be operated with stagnation conditions near the triple point conditions and choked flow at the exit. The condition of a limiting mass flow rate of the order of 10 -6 kg/s together with the operating conditions bound the exit diameter to values of 200-250 μm. Other geometrical parameters have only a subordinate importance on the injection nozzle design

  16. Synthesis of the AB ring system of clifednamide utilizing Claisen rearrangement and Diels-Alder reaction as key steps.

    Science.gov (United States)

    Loke, Inga; Bentzinger, Guillaume; Holz, Julia; Raja, Aruna; Bhasin, Aman; Sasse, Florenz; Köhn, Andreas; Schobert, Rainer; Laschat, Sabine

    2016-01-21

    In order to construct the functionalized AB ring system of clifednamide, member of the class of macrocyclic tetramic acid lactams, a synthesis was developed which utilized an Ireland-Claisen rearrangement and an intramolecular Diels-Alder reaction. Starting from di-O-isopropylidene-d-mannitol the allyl carboxylate precursor for the sigmatropic rearrangement was prepared. This rearrangement proceeded diastereoselectively only in the presence of an allyl silyl ether instead of the parent enone in the side chain, as suggested by deuteration experiments. A subsequent Diels-Alder reaction yielded the target ethyl hexahydro-1H-indene-carboxylate with high diastereoselectivity. Quantum-chemical investigations of this intramolecular Diels-Alder reaction support the proposed configuration of the final product.

  17. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

    The structure of the Saturnian rings is traditionally believed to be due to resonances caused by Mimas (and possibly other satellites). It is shown that both theoretical and observational evidence rule out this interpretation. The increased observational accuracy on one hand and the increased understanding of the cosmogonic processes on the other makes it possible to explain the structure of the ring system as a product of condensation from a partially corotating plasma. In certain respects the agreement between theory and observations is about 1%. (Auth.)

  18. Positron ring system using anger-type detectors. Progress report, January 1-December 31, 1986

    International Nuclear Information System (INIS)

    Muehllehner, G.

    1986-09-01

    The design of a new multislice system consisting of six position-sensitive area detectors has been completed, and the system is now in the final assembly phase. This system will be able to reconstruct a volume 50 cm in diameter and 10 cm long with equal resolution of 4 to 5 mm in all directions. The system achieves high sensitivity through a large acceptance angle which is made possible through the use of three-dimensional reconstruction algorithms

  19. Badly approximable systems of linear forms in absolute value

    DEFF Research Database (Denmark)

    Hussain, M.; Kristensen, Simon

    In this paper we show that the set of mixed type badly approximable simultaneously small linear forms is of maximal dimension. As a consequence of this theorem we settle the conjecture stated in [9]....

  20. Linking Equilibrium and Nonequilibrium Dynamics in Glass-Forming Systems

    DEFF Research Database (Denmark)

    Mauro, John C.; Guo, Xiaoju; Smedskjær, Morten Mattrup

    , we show that the nonequilibrium glassy dynamics are intimately connected with the equilibrium liquid dynamics. This is accomplished by deriving a new functional form for the thermal history dependence of nonequilibrium viscosity, which is validated against experimental measurements of industrial...

  1. Metrical theorems on systems of small inhomogeneous linear forms

    DEFF Research Database (Denmark)

    Hussain, Mumtaz; Kristensen, Simon

    In this paper we establish complete Khintchine-Groshev and Schmidt type theorems for inhomogeneous small linear forms in the so-called doubly metric case, in which the inhomogeneous parameter is not fixed.......In this paper we establish complete Khintchine-Groshev and Schmidt type theorems for inhomogeneous small linear forms in the so-called doubly metric case, in which the inhomogeneous parameter is not fixed....

  2. Metrical results on systems of small linear forms

    DEFF Research Database (Denmark)

    Hussain, M.; Kristensen, Simon

    In this paper the metric theory of Diophantine approximation associated with the small linear forms is investigated. Khintchine--Groshev theorems are established along with Hausdorff measure generalization without the monotonic assumption on the approximating function.......In this paper the metric theory of Diophantine approximation associated with the small linear forms is investigated. Khintchine--Groshev theorems are established along with Hausdorff measure generalization without the monotonic assumption on the approximating function....

  3. Rare earth mobility in hydrothermal ore-forming systems

    International Nuclear Information System (INIS)

    Cornell, D.H.; Schade, J.; Scheepers, R.; Watkeys, M.K.

    1988-01-01

    Rocks and ores which form by magmatic processes display a range of chondrite-normalised rare earth profiles. One REE (rare earth elements) profile feature which seems unrelated to magmatic processes is the birdwing profile, in which both heavy and light rare earths are enriched relative to the middle rare earths. Birdwing rare earth profiles are an easily identified geochemical anomaly. It is proposed that rare earth geochemistry could be applied in geochemical prospecting for ore formed by hydrothermal processes. 5 figs

  4. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  5. RAPID FREEFORM SHEET METAL FORMING: TECHNOLOGY DEVELOPMENT AND SYSTEM VERIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Kiridena, Vijitha [Ford Scientific Research Lab., Dearborn, MI (United States); Verma, Ravi [Boeing Research and Technology (BR& T), Seattle, WA (United States); Gutowski, Timothy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Roth, John [Pennsylvania State Univ., University Park, PA (United States)

    2018-03-31

    The objective of this project is to develop a transformational RApid Freeform sheet metal Forming Technology (RAFFT) in an industrial environment, which has the potential to increase manufacturing energy efficiency up to ten times, at a fraction of the cost of conventional technologies. The RAFFT technology is a flexible and energy-efficient process that eliminates the need for having geometry-specific forming dies. The innovation lies in the idea of using the energy resource at the local deformation area which provides greater formability, process control, and process flexibility relative to traditional methods. Double-Sided Incremental Forming (DSIF), the core technology in RAFFT, is a new concept for sheet metal forming. A blank sheet is clamped around its periphery and gradually deformed into a complex 3D freeform part by two strategically aligned stylus-type tools that follow a pre-described toolpath. The two tools, one on each side of the blank, can form a part with sharp features for both concave and convex shapes. Since deformation happens locally, the forming force at any instant is significantly decreased when compared to traditional methods. The key advantages of DSIF are its high process flexibility, high energy-efficiency, low capital investment, and the elimination of the need for massive amounts of die casting and machining. Additionally, the enhanced formability and process flexibility of DSIF can open up design spaces and result in greater weight savings.

  6. Ground Movement in SSRL Ring

    International Nuclear Information System (INIS)

    Sunikumar, Nikita

    2011-01-01

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  7. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  8. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.

    2010-01-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  9. Transparent form-active system with structural glass

    NARCIS (Netherlands)

    Nikolaou, M.S.N.; Veer, F.A.; Eigenraam, P.

    2015-01-01

    Free-form transparent wide-span spatial structures which have being constructed so far, are based on the concept of three sets of components, the structural components, usually steel elements to ensure both compressive and tensional capacity; the glass cladding elements for expressing transparency;

  10. Detection of the water reservoir in a forming planetary system

    NARCIS (Netherlands)

    Hogerheijde, M.R.; Bergin, E.A.; Brinch, C.; Cleeves, L.I.; Fogel, J. K.J.; Blake, G.A.; Dominik, C.; Lis, D.C.; Melnick, G.; Neufeld, D.; Panić, O.; Pearson, J.C.; Kristensen, L.; Yıldız, U.A.; van Dishoeck, E.F.

    2011-01-01

    Icy bodies may have delivered the oceans to the early Earth, yet little is known about water in the ice-dominated regions of extrasolar planet-forming disks. The Heterodyne Instrument for the Far-Infrared on board the Herschel Space Observatory has detected emission lines from both spin isomers of

  11. The TubR-centromere complex adopts a double-ring segrosome structure in Type III partition systems.

    Science.gov (United States)

    Martín-García, Bárbara; Martín-González, Alejandro; Carrasco, Carolina; Hernández-Arriaga, Ana M; Ruíz-Quero, Rubén; Díaz-Orejas, Ramón; Aicart-Ramos, Clara; Moreno-Herrero, Fernando; Oliva, María A

    2018-05-14

    In prokaryotes, the centromere is a specialized segment of DNA that promotes the assembly of the segrosome upon binding of the Centromere Binding Protein (CBP). The segrosome structure exposes a specific surface for the interaction of the CBP with the motor protein that mediates DNA movement during cell division. Additionally, the CBP usually controls the transcriptional regulation of the segregation system as a cell cycle checkpoint. Correct segrosome functioning is therefore indispensable for accurate DNA segregation. Here, we combine biochemical reconstruction and structural and biophysical analysis to bring light to the architecture of the segrosome complex in Type III partition systems. We present the particular features of the centromere site, tubC, of the model system encoded in Clostridium botulinum prophage c-st. We find that the split centromere site contains two different iterons involved in the binding and spreading of the CBP, TubR. The resulting nucleoprotein complex consists of a novel double-ring structure that covers part of the predicted promoter. Single molecule data provides a mechanism for the formation of the segrosome structure based on DNA bending and unwinding upon TubR binding.

  12. The real-time orbit-position feedback system for the ELETTRA storage ring

    International Nuclear Information System (INIS)

    Bulfone, D.

    1990-01-01

    To take full advantage of the low emittance and the small insertion-device source sizes, real-time global harmonic and local feedback systems have been designed for the Trieste synchrotron light source (ELETTRA). A fully digital approach has been chosen for data communication and processing, using VME as the standard system bus. The system architecture is presented, showing the open approach which allows a free choice in the use of beam-position monitors and correctors. The design considerations are given, pointing out the advantages in flexibility offered by the digital processing. (orig.)

  13. Centralized multiprocessor control system for the frascati storage rings DAΦNE

    International Nuclear Information System (INIS)

    Di Pirro, G.; Milardi, C.; Serio, M.

    1992-01-01

    We describe the status of the DANTE (DAΦne New Tools Environment) control system for the new DAΦNE Φ-factory under construction at the Frascati National Laboratories. The system is based on a centralized communication architecture for simplicity and reliability. A central processor unit coordinates all communications between the consoles and the lower level distributed processing power, and continuously updates a central memory that contains the whole machine status. We have developed a system of VME Fiber Optic interfaces allowing very fast point to point communication between distant processors. Macintosh II personal computers are used as consoles. The lower levels are all built using the VME standard. (author)

  14. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  15. Non-Linear Dynamics of Saturn's Rings

    Science.gov (United States)

    Esposito, L. W.

    2016-12-01

    Non-linear processes can explain why Saturn's rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. Stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, that push the system across thresholds that lead to persistent states. Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit, with relative velocity ranging from nearly zero to a multiple of the orbit average. Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like `straw' that can explain the halo morphology and spectroscopy: Cyclic velocity changes cause perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; surrounding particles diffuse back too slowly to erase the effect: this gives the halo morphology; this requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping explains both small and large particles at resonances. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating it as an asymmetric random walk with reflecting boundaries

  16. Solving Fully Fuzzy Linear System of Equations in General Form

    Directory of Open Access Journals (Sweden)

    A. Yousefzadeh

    2012-06-01

    Full Text Available In this work, we propose an approach for computing the positive solution of a fully fuzzy linear system where the coefficient matrix is a fuzzy $nimes n$ matrix. To do this, we use arithmetic operations on fuzzy numbers that introduced by Kaffman in and convert the fully fuzzy linear system into two $nimes n$ and $2nimes 2n$ crisp linear systems. If the solutions of these linear systems don't satisfy in positive fuzzy solution condition, we introduce the constrained least squares problem to obtain optimal fuzzy vector solution by applying the ranking function in given fully fuzzy linear system. Using our proposed method, the fully fuzzy linear system of equations always has a solution. Finally, we illustrate the efficiency of proposed method by solving some numerical examples.

  17. Decision structures in franchise systems of the plural form

    OpenAIRE

    Kranz, Sebastian; Lewin-Solomons, Shira B.

    2008-01-01

    Many successful franchise chains directly own a positive fraction of stores --- a structure referred to as plural form. We propose that this ownership structure is chosen as a commitment not to expropriate franchisees. The theoretical model is based on an empirical analysis of contract and interview data from the US fast-food sector and well known stylized facts: First, franchisees typically have strong contractual obligations to implement activities selected by the chain. Second, franchisees...

  18. An active interlock system for the NSLS x-ray ring insertion devices

    International Nuclear Information System (INIS)

    Nawrocky, R.J.; Biscardi, R.; Dabrowski, J.; Flannigan, J.; Ramamoorthy, S.; Rothman, J.; Smith, J.; So, I.; Thomas, M.; Decker, G.

    1991-01-01

    This paper describes the design and operation of an active interlock system which has been installed in the NSLS X-ray electron storage ing to protect the vacuum chamber from thermal damage by mis-steered high power photon beams from insertion devices (IDs). the system employs active beam position detectors to monitor beam motion in the ID straight sections and solid state logic circuitry to ''dump'' the stored beam in the event of a fault condition by interrupting the rf. To ensure a high degree of reliability, redundancy and continuous automatic checking has been incorporated into the design. Overall system integrity is checked periodically with beam at safe levels of beam current. 2 refs., 3 figs

  19. Rings Research in the Next Decade

    Science.gov (United States)

    Burns, J. A.; Tiscareno, M. S.

    2009-12-01

    The study of planetary ring systems forms a key component of planetary science for several reasons: 1) The evolution and current states of planets and their satellites are affected in many ways by rings, while 2) conversely, properties of planets and moons and other solar system populations are revealed by their effects on rings; 3) highly structured and apparently delicate ring systems may be bellwethers, constraining various theories of the origin and evolution of their entire planetary system; and finally, 4) planetary rings provide an easily observable analogue to other astrophysical disk systems, enabling real “ground truth” results applicable to disks much more remote in space and/or time, including proto-planetary disks, circum-stellar disks, and even galaxies. Significant advances have been made in rings science in the past decade. The highest-priority rings research recommendations of the last Planetary Science Decadal Survey were to operate and extend the Cassini orbiter mission at Saturn; this has been done with tremendous success, accounting for much of the progress made on key science questions, as we will describe. Important progress in understanding the rings of Saturn and other planets has also come from Earth-based observational and theoretical work, again as prioritized by the last Decadal Survey. However, much important work remains to be done. At Saturn, the Cassini Solstice Mission must be brought to a successful completion. Priority should also be placed on sending spacecraft to Neptune and/or Uranus, now unvisited for more than 20 years. At Jupiter and Pluto, opportunities afforded by visiting spacecraft capable of studying rings should be exploited. On Earth, the need for continued research and analysis remains strong, including in-depth analysis of rings data already obtained, numerical and theoretical modeling work, laboratory analysis of materials and processes analogous to those found in the outer solar system, and continued Earth

  20. Device for monitoring electron-ion ring parameters

    International Nuclear Information System (INIS)

    Tyutyunnikov, S.I.; Shalyapin, V.N.

    1982-01-01

    The invention is classified as the method of collective ion acceleration. The device for electron-ion ring parameters monitoring is described. The invention is aimed at increasing functional possibilities of the device at the expense of the enchance in the number of the ring controlled parameters. The device comprises three similar plane mirrors installed over accelerating tube circumference and a mirror manufactured in the form of prism and located in the tube centre, as well as the system of synchrotron radiation recording and processing. Two plane mirrors are installed at an angle of 45 deg to the vertical axis. The angle of the third plane mirror 3 α and that of prismatic mirror 2 α to the vertical axis depend on geometric parameters of the ring and accelerating tube and they are determined by the expression α=arc sin R K /2(R T -L), where R K - ring radius, R T - accelerating tube radius, L - the height of segment, formed by the mirror and inner surface of the accelerating tube. The device suggested permits to determine longitudinal dimensions of the ring, its velocity and the number of electrons and ions in the ring

  1. Synthesis of Polycyclic Ring Systems Using Transition Metal Catalyzed Cyclizations of Diazo Alkynyl Ketones

    Directory of Open Access Journals (Sweden)

    Albert Padwa

    2000-12-01

    Full Text Available The rhodium(II-catalyzed reaction of α-diazo ketones bearing tethered alkyne units represents a new and useful method for the construction of a variety of substituted cyclopentenones. The process proceeds by addition of the rhodium-stabilized carbenoid onto the acetylenic π-bond to give a vinyl carbenoid intermediate. The resulting rhodium complex undergoes a wide assortment of reactions including cyclopropanation, 1,2-hydrogen migration, CH-insertion, addition to tethered alkynes and ylide formation. When 2-alkynyl-2-diazo-3-oxobutanoates were treated with a Rh(II-catalyst, furo[3,4-c]furans were formed in excellent yield.

  2. Self-seeded single-frequency solid-state ring laser and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-02-20

    A method of operating a laser to obtain an output pulse having a single wavelength, comprises inducing an intracavity loss into a laser resonator having an amount that prevents oscillation during a time that energy from the pump source is being stored in the gain medium. Gain is built up in the gain medium with energy from the pump source until formation of a single-frequency relaxation oscillation pulse in the resonator. Upon detection of the onset of the relaxation oscillation pulse, the intracavity loss is reduced, such as by Q-switching, so that the built-up gain stored in the gain medium is output from the resonator in the form of an output pulse at a single frequency. An electronically controllable output coupler is controlled to affect output pulse characteristics. The laser acts a master oscillator in a master oscillator power amplifier configuration. The laser is used for laser peening.

  3. Design of the Beam Loss Monitoring System for the LHC Ring

    CERN Document Server

    Holzer, E B; Effinger, E; Ferioli, G; González, J L; Gschwendtner, E; Guaglio, Gianluca; Hodgson, M; Prieto, V; Zamantzas, C

    2004-01-01

    The beam loss monitoring (BLM) system of the LHC is one of the most critical elements for the protection of the LHC. It must prevent the super conducting magnets from quenches and the machine components from damages, caused by beam losses. It helps in the identification of the loss mechanism by measuring the loss pattern. Special detectors will be used for the setup and control of the collimators. Furthermore, it will be an important tool during machine setup and studies. The specification requirements of the BLM system include a very high reliability.

  4. A free-flowing soap film combined with cavity ring-down spectroscopy as a detection system for liquid chromatography.

    Science.gov (United States)

    Vogelsang, Markus; Welsch, Thomas; Jones, Harold

    2010-05-07

    We have shown that a free-flowing soap film has sufficiently high-quality optical properties to allow it to be used in the cavity of a ring-down spectrometer (CRDS). The flow rates required to maintain a stable soap film were similar to those used in liquid chromatography and thus allowed interfacing with an HPLC system for use as an optical detector. We have investigated the properties of the system in a relevant analytical application. The soap film/CRDS combination was used at 355 nm as a detector for the separation of a mixture of nitroarenes. These compounds play a role in the residue analysis of areas contaminated with explosives and their decomposition products. In spite of the short absorption path length (9 microm) obtained by the soap film, the high-sensitivity of CRDS allowed a limit of detection of 4 x 10(-6) in absorption units (AU) or less than 17 fmol in the detection volume to be achieved. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  5. On a possibility of using a superconducting cavity in the RF system of the storage ring LESR-N100

    CERN Document Server

    Androsov, V P; Telegin, Yu P

    2002-01-01

    In the Kharkov Institute of Physics and Technology the design project of the 200 MeV electron storage ring LESR-N100 is under development. The essential feature of this facility is the large beam energy spread (of about 1%). To ensure a reasonable beam lifetime the RF-system should provide the accelerating voltage of about 0.5 MV, while the total energy losses do not exceed approx 700 eV/turn. The power dissipated in two 700 MHz normal-conducting (NC) cavities much exceeds the power transmitted to the beam. We considered a possibility to use in LESR-N100 a high-Q superconducting RF-cavity (SRF-cavity) in which the dissipated power is the same order of magnitude as the beam-transmitted power. The studies show that the system with SRF-cavity cannot operate in the standard mode when the cavity is matched to the power transmission line at some nominal beam current. The optimal operation mode with high overcoupling is proposed that requires the RF-power one order of magnitude less than in the case of Nc-cavities.

  6. Simulation of a ring resonator-based optical beamformer system for phased array receive antennas

    NARCIS (Netherlands)

    Tijmes, M.R.; Meijerink, Arjan; Roeloffzen, C.G.H.; Bentum, Marinus Jan

    2009-01-01

    A new simulator tool is described that can be used in the field of RF photonics. It has been developed on the basis of a broadband, continuously tunable optical beamformer system for phased array receive antennas. The application that is considered in this paper is airborne satellite reception of

  7. Nuclear information systems: Forming the hub of quality assurance

    International Nuclear Information System (INIS)

    Shepherd, S.H.

    1990-01-01

    Data processing, storage, and transmission technology has advanced sufficiently that nuclear information system networks are developing at many nuclear power plant sites. The networks offer much promise - repetitive tasks can be eliminated, cross checks and reviews can be implemented, and the user can do a more thorough, more professional job. With the arrival of this new power to analyze, plan, communicate, and simplify work comes a duty to properly harness the power. If the power of the information age is misused, or used carelessly, much damage can be done. When it comes to nuclear applications, there are really only three significant features to an information system: quality, reliability, and security. Put simply, the user must trust the accuracy of the system or it cannot be used. A system that is not available for use on demand will not be in demand for long. Fast processors, video graphics, and laser publishing are worthless if one must back up the system with hand calculations and tedious verification of data. An effective nuclear information system has good quality practices interwoven into the hardware and software, so that the system itself can foster and promote better quality assurance

  8. Influence of ring growth rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

    2015-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

  9. Computational study of hydrogen shifts and ring-opening mechanisms in α-pinene ozonolysis products

    DEFF Research Database (Denmark)

    Kurtén, Theo; Rissanen, Matti P.; Mackeprang, Kasper

    2015-01-01

    , sterically unhindered) H-shifts of all four peroxy radicals formed in the ozonolysis of α-pinene using density functional (ωB97XD) and coupled cluster [CCSD(T)-F12] theory. In contrast to the related but chemically simpler cyclohexene ozonolysis system, none of the calculated H-shifts have rate constants...... products in the α-pinene ozonolysis system, additional ring-opening reaction mechanisms breaking the cyclobutyl ring are therefore needed. We further investigate possible uni- and bimolecular pathways for opening the cyclobutyl ring in the α-pinene ozonolysis system....

  10. Preliminary design of the pulse generator for the CLIC damping ring extraction system

    CERN Document Server

    Holma, Janne; Ovaska, Seppo

    2011-01-01

    The spent drive beam must be cleanly extracted and bent away from the decelerator axis at the end of each CLIC decelerator in order to leave space for injecting a fresh beam train in the next sector. Then the spent beam must be safely absorbed. A compact extraction system made of a single dipole is proposed. The spent beam is driven to a water dump located at 20m downstream of the extraction point and transversely 6m away of the axis of the main linac. An adequate spread of the beam impact map on the dump offers small temperature excursions in both the dump and its entrance window, allowing for reliable operation and a long lifetime of the system.

  11. Position Ring System using Anger Type Detectors. Progress Report (1999-2002)

    International Nuclear Information System (INIS)

    Karp, Joel S.

    2004-01-01

    The overall objective of our project was to develop PET scanners and imaging techniques that achieve high performance and excellent image quality. Our approach was based upon 3-D imaging (no septa) with position-sensitive Anger-logic detectors, whereby the encoding ratio of resolution elements to number of photo-multiplier tube channels is very high. This design led to a series of PET systems that emphasized cost-effectiveness and practicality in a clinical environment.

  12. forms and sources of conflict in nigerian educational system

    African Journals Online (AJOL)

    PROF EKWUEME

    conflicts in Nigerian Educational system, the need for modification of the Nigerian psyche, the Peace and Conflict Resolution in .... social psychology; modern mathematics, population ... indigenous or traditional education boldly emerged for ...

  13. Self-gravitation in Saturn's rings

    International Nuclear Information System (INIS)

    Salo, H.; Lukkari, J.

    1982-01-01

    In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)

  14. First-order systems of linear partial differential equations: normal forms, canonical systems, transform methods

    Directory of Open Access Journals (Sweden)

    Heinz Toparkus

    2014-04-01

    Full Text Available In this paper we consider first-order systems with constant coefficients for two real-valued functions of two real variables. This is both a problem in itself, as well as an alternative view of the classical linear partial differential equations of second order with constant coefficients. The classification of the systems is done using elementary methods of linear algebra. Each type presents its special canonical form in the associated characteristic coordinate system. Then you can formulate initial value problems in appropriate basic areas, and you can try to achieve a solution of these problems by means of transform methods.

  15. Design and finite element simulation of vacuum systems for insertion devices in Indus-2 storage ring

    International Nuclear Information System (INIS)

    Yadav, D.P.; Bais, Vijay; Sridhar, R.; Dhimole, Vivek K.; Nitesh, Suthar; Rawal, B.R.; Chogaonkar, Swati

    2015-01-01

    Indus-2 is a 2.5 GeV, 300 mA, Synchrotron Radiation Source (SRS) located at Raja Ramanna Centre for Advanced Technology, Indore. As part of insertion device (ID) development programme two new devices namely, APPLE-2 (Advanced Planar Polarized Light Emitter) type Undulator (also known as U-3 Undulator) and 5 Tesla superconducting wavelength shifter (SWLS) are being developed. APPLE-2 will generate variably polarized synchrotron radiation (SR) required for carrying out magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) experiments and SWLS will generate synchrotron radiation (SR) with critical photon energy of about 20.8 keV for Energy Dispersive XRD beam line. This paper describes design details and finite element analysis results of various simulations carried out for the vacuum systems of these IDs

  16. Finite Horizon MPC for Systems in Innovation Form

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp; Huusom, Jakob Kjøbsted; Rawlings, James B.

    2011-01-01

    System identification and model predictive control have largely developed as two separate disciplines. Nevertheless, the major part of industrial MPC commissioning is generation of data and identification of models. In this contribution we attempt to bridge this gap by contributing some of the mi...

  17. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J

    2003-03-11

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 {mu}m Si detector, a second 300 {mu}m (or possibly 500 {mu}m) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 {mu}m Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 {mu}m Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution {<=}8%, while the standard 300 {mu}m detectors have {<=}2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10{sup 10} alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented.

  18. CHICSi - a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. II. Detectors

    International Nuclear Information System (INIS)

    Golubev, P.; Avdeichikov, V.; Carlen, L.; Jakobsson, B.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.

    2003-01-01

    We describe the detectors for identification of charged particles and fragments in CHICSi, a large solid angle multi-telescope system mounted inside an ultra-high vacuum (UHV), cluster-jet target chamber. CHICSi performs nuclear reaction experiments at storage rings. The telescopes consist of a first very thin, 10-14 μm Si detector, a second 300 μm (or possibly 500 μm) ion implanted Si detector supplemented by a 6 mm GSO(Ce) scintillator read out by a photodiode (PD) or by a third 300 μm Si detector. The telescopes provide full charge separation up to Z=17 and mass resolution up to A=9 in the energy range 0.7-60A MeV. The thin p-i-n diode detector, etched out from a 280 μm Si wafer, and the GSO/PD detector, both exclusively developed for CHICSi, provide an energy resolution ≤8%, while the standard 300 μm detectors have ≤2% energy resolution. Radiation stability of the Si detectors is confirmed up to an integrated flux of 10 10 alpha particles. The GSO detector has 70% light collection efficiency with the optical coupling to the PD a simple open, 0.2 mm, gap. A new method, developed to perform absolute energy calibration for the GSO/PD detector is presented

  19. Reacquisition of E-cadherin expression in metastatic deposits of signet-ring cell carcinoma of the upper gastrointestinal system: a potential anchor for metastatic deposition.

    Science.gov (United States)

    Ma, Yihong R; Siegal, Gene P; Wei, Shi

    2017-06-01

    To examine the expression of E-cadherin in paired primary and metastatic signet-ring cell carcinomas (SRCC) of various organ systems in order to explore the potential role of the molecule in metastatic dissemination of this unique tumour type. Thirty-seven consecutive cases of SRCC from various organs with paired primary and metastatic tumorous tissue available were retrieved. The intensity of membranous E-cadherin expression was semiquantitatively scored on a scale of 0-3+. Reduced E-cadherin expression was a distinct feature of primary SRCC and was observed in 78% of primary tumours. Interestingly, the E-cadherin reduction was less frequently seen in metastatic SRCC when compared with their primary counterparts, and was only found in 57% of tumours in lymph node metastases or at distant sites of relapse. Furthermore, the mean score of E-cadherin expression of primary SRCC was significantly lower than that of their metastatic counterparts (2.3 vs 1.8; p=0.008). When divided by organ systems, the reacquisition of E-cadherin expression in the metastatic deposits was most remarkable in the SRCC of upper gastrointestinal tract origin (2.3 vs 1.4; p=0.003), whereas no significant difference was observed in other organ systems. While the reduction of E-cadherin in primary SRCC supports its pivotal role in epithelial-mesenchymal transition, a process crucial in tumour progression and metastatic dissemination, the re-expression of this molecule in metastatic SRCC cells implies a reversal to their epithelial phenotype (thus mesenchymal-epithelial transition) which, in turn, theoretically helps tumour cells to anchor and form cohesive metastatic deposits. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Methods of forming thermal management systems and thermal management methods

    Science.gov (United States)

    Gering, Kevin L.; Haefner, Daryl R.

    2012-06-05

    A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

  1. Microvascular system forming in skeletal muscle near trichinella larvae

    International Nuclear Information System (INIS)

    Berzentsev, Y.A.; Oksov, I.V.

    1986-01-01

    The fine structure and dynamics of formation of the microcirculatory system about the larvae of the two Trichinella species, providing for the rapid entry of nutrient substances to the larvae, were investigated in the muscles of white mice. Hitological, hitochemical, autoradiographic, and electron-microscopic methods were used in the investigation. At a certain period of the experiment, the greatest quantity of RNA was found in the endotheliocyte cytoplasm, tritium-thymidine label was incorporated into the nuclei, and mitoses were visible. The transition to tissue parasitism was accompanied by a complication of the relationships with the host and the formation of a more complex independent microcirculatory system, which ensures a more intensive influx of blood

  2. A novel FPGA-based bunch purity monitor system at the APS storage ring

    International Nuclear Information System (INIS)

    Norum, W.E.

    2008-01-01

    Bunch purity is an important source quality factor for the magnetic resonance experiments at the Advanced Photon Source. Conventional bunch-purity monitors utilizing time-to-amplitude converters are subject to dead time. We present a novel design based on a single field- programmable gate array (FPGA) that continuously processes pulses at the full speed of the detector and front-end electronics. The FPGA provides 7778 single-channel analyzers (six per rf bucket). The starting time and width of each single-channel analyzer window can be set to a resolution of 178 ps. A detector pulse arriving inside the window of a single-channel analyzer is recorded in an associated 32-bit counter. The analyzer makes no contribution to the system dead time. Two channels for each rf bucket count pulses originating from the electrons in the bucket. The other four channels on the early and late side of the bucket provide estimates of the background. A single-chip microcontroller attached to the FPGA acts as an EPICS IOC to make the information in the FPGA available to the EPICS clients.

  3. TECHNOLOGY FORMING PRICE DISTRIBUTION OF FINISHED GOODS OF LOGISTICS SYSTEM

    Directory of Open Access Journals (Sweden)

    Novikova T. V.

    2015-12-01

    Full Text Available Modern economics has developed a number of areas of the system for controlling the distribution of finished products. However, in domestic and foreign economic literature the mechanisms of logistics approach are not sufficient to provide higher sales of enterprise-producers, that have sales in remote areas. In this study, first, the importance of company-producers and end-users the methods of rational delivery of finished products is considered, and secondly, the approaches to defining the essence and content of the concept of «distribution» are given, in the third, the logistics processes of the distribution system ready products of a particular company-producer are described, fourthly, the technology of one price product delivery was developed and it was shown the economic efficiency (the possible results of the solution of the problem of distribution logistics of its application in the target company. The study showed that there is an opportunity, based on the development and implementation of technologies to reduce the final price of the goods, to develop the company and increase its competitiveness by minimizing costs and increasing return on investment. The results of research extend the knowledge of methodology of system logistics management in the enterprise.

  4. Kayser-Fleischer Rings

    Science.gov (United States)

    ... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

  5. Entropy of the system formed in heavy ion collision

    International Nuclear Information System (INIS)

    Gudima, K.K.; Schulz, H.; Toneev, V.D.

    1985-01-01

    In frames of a cascade model the entropy evolution in a system producted in heavy ion collisions is investigated. Entropy calculation is based on smoothing of the distribution function over the momentum space by the temperature field introduction. The resulting entropy per one nucleon is shown to be rather sensitive to phase space subdivision into cells at the stage of free scattering of reaction products. Compared to recent experimental results for specific entropy values inferred from the composite particle yield of 4π measurements, it is found that cascade calculations do not favour some particular entropy model treatments and suggest smaller entropy values than following from consideration within equilibrium statistics

  6. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

    Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

  7. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1982-01-01

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  8. Minimal Gromov-Witten rings

    International Nuclear Information System (INIS)

    Przyjalkowski, V V

    2008-01-01

    We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

  9. FORMING MANAGEMENT IMPACTS IN AVIATION COMPANIES ECONOMIC DEVELOPMENT ADMINISTRATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Victoria Prokhorova

    2016-06-01

    Full Text Available Purpose: Oriented reflective approach to management involves restructuring of goal, ideal and pragmatic, creating a program of action, organizing, correcting, control the definition of the new strategy. This process is only possible with multidimensional analysis and reflection of all the administrative restructuring process and its elements in determining and planning activities, creating conditions of restructuring, predicting outcomes and consequences of making a choice of ways to solve problems means to achieve the goal of information called ' bonds with participants restructuring process and correction flow management process based on continuous reflection. Methods: Development of the system of economic development now requires the use of mechanisms for continuous monitoring of internal and external environment to identify factors that threaten businesses. Rest of this is possible through the use of diagnostic tests: static analysis, expert diagnosis, linear and dynamic programming. Results: Built as part of the study economic and mathematical models can determine the status and level of economic development potential of aerospace companies that were investigated, confirming the need for action to manage economic development. To develop the mechanism of competition in the aircraft building sector must: implementation in practice of management motivation mechanisms to ensure the appropriate level of interest in the functioning of airlines on the basis of private property; formation of economic market institutions in the field of aircraft construction, affecting the creation of a competitive environment. Discussion: Stipulates that in difficult economic crisis positive results can be achieved managers who are constantly looking for original approaches to inclusion in the development process by aligning internal external opportunities generated by market. It is concluded that aviation business management in times of economic instability or

  10. GPU-based low-level trigger system for the standalone reconstruction of the ring-shaped hit patterns in the RICH Cherenkov detector of NA62 experiment

    International Nuclear Information System (INIS)

    Ammendola, R.; Biagioni, A.; Cretaro, P.; Frezza, O.; Cicero, F. Lo; Lonardo, A.; Martinelli, M.; Paolucci, P.S.; Pastorelli, E.; Chiozzi, S.; Ramusino, A. Cotta; Fiorini, M.; Gianoli, A.; Neri, I.; Lorenzo, S. Di; Fantechi, R.; Piandani, R.; Pontisso, L.; Lamanna, G.; Piccini, M.

    2017-01-01

    This project aims to exploit the parallel computing power of a commercial Graphics Processing Unit (GPU) to implement fast pattern matching in the Ring Imaging Cherenkov (RICH) detector for the level 0 (L0) trigger of the NA62 experiment. In this approach, the ring-fitting algorithm is seedless, being fed with raw RICH data, with no previous information on the ring position from other detectors. Moreover, since the L0 trigger is provided with a more elaborated information than a simple multiplicity number, it results in a higher selection power. Two methods have been studied in order to reduce the data transfer latency from the readout boards of the detector to the GPU, i.e., the use of a dedicated NIC device driver with very low latency and a direct data transfer protocol from a custom FPGA-based NIC to the GPU. The performance of the system, developed through the FPGA approach, for multi-ring Cherenkov online reconstruction obtained during the NA62 physics runs is presented.

  11. Algebra and Arithmetic of Modular Forms

    DEFF Research Database (Denmark)

    Rustom, Nadim

    In [Rus14b] and [Rus14a], we study graded rings of modular forms over congruence subgroups, with coefficients in subrings A of C, and determine bounds of the weights of modular forms constituting a minimal set of generators, as well as on the degree of the generators of the ideal of relations...... between them. We give an algorithm that computes the structures of these rings, and formulate conjectures on the minimal generating weight for modular forms with coefficients in Z. We discuss questions of finiteness of systems of Hecke eigenvalues modulo pm, for a prime p and an integer m ≥ 2, in analogy...

  12. Strings, vortex rings, and modes of instability

    Directory of Open Access Journals (Sweden)

    Steven S. Gubser

    2015-03-01

    Full Text Available We treat string propagation and interaction in the presence of a background Neveu–Schwarz three-form field strength, suitable for describing vortex rings in a superfluid or low-viscosity normal fluid. A circular vortex ring exhibits instabilities which have been recognized for many years, but whose precise boundaries we determine for the first time analytically in the small core limit. Two circular vortices colliding head-on exhibit stronger instabilities which cause splitting into many small vortices at late times. We provide an approximate analytic treatment of these instabilities and show that the most unstable wavelength is parametrically larger than a dynamically generated length scale which in many hydrodynamic systems is close to the cutoff. We also summarize how the string construction we discuss can be derived from the Gross–Pitaevskii Lagrangian, and also how it compares to the action for giant gravitons.

  13. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

    It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

  14. From the Icy Satellites to Small Moons and Rings: Spectral Indicators by Cassini-VIMS Unveil Compositional Trends in the Saturnian System

    Science.gov (United States)

    Filacchione, G.; Capaccioni, F.; Ciarniello, M.; Nicholson, P. D.; Clark, R. N.; Cuzzi, J. N.; Buratti, B. B.; Cruikshank, D. P.; Brown, R. H.

    2017-01-01

    flat reflectance in the visible, making them remarkably different with respect to the other small moons. Moreover, we have observed that the two Tethys' lagrangian moons appear spectrally different, with Calypso characterized by more intense water ice bands than Telesto. Conversely, at visible wavelengths Polydeuces, Telesto and Methone are in absolute the more blue objects in the Saturn's system. The red slopes measured in the visible range on disk-integrated spectral data, showing varying degrees on all of the satellites, could be caused more by exogenic processes than by geologic and endogenic events which are operating on more localized scales. The principal exogenic processes active in the Saturn's system [11] which alter the satellites and rings surfaces are the E ring particles bombardment, the interaction with corotating plasma and energetic particles, the bombardment of exogenic dark material [12] and the water ice photolysis. A discussion about the correlations between these processes and the o bserved spectral classes is given. With the approaching of the Cassini "Gran Finale" orbits, VIMS will unveil with unprecedented spatial resolution the spectral properties of many small moons and rings. These data will be extremely valuable to improve our classification of the Saturn's satellites and rings.

  15. Investigation of transient processes at the DELTA electron storage ring using a digital bunch-by-bunch feedback system

    Energy Technology Data Exchange (ETDEWEB)

    Hoener, Markus

    2015-07-01

    At the 1.5-GeV synchrotron radiation source DELTA, operated by the TU Dortmund University, intensive synchrotron radiation in the spectral range from hard X-rays to THz radiation is generated by the circular deflection of highly relativistic electron bunches. Interacting with the vacuum chamber wall, the electron bunches create electric fields, which can act back on subsequent bunches. With increasing beam current, the excitation is enhanced so that the electron beam is unstable, which means that the electron bunches oscillate longitudinally or transversely relative to their reference position. The oscillations reduce the quality of the synchrotron radiation and limit the maximum storable beam current. Within the scope of this thesis, the beam instabilities at the storage ring were systematically investigated. A digital bunch-by-bunch feedback system was installed and commissioned, which allows to detect and digitize the position of each electron bunch at each turn. Based on the input signal, a correction signal is calculated in order to suppress transverse and longitudinal oscillation of the bunches. In addition, it is possible to excite dedicated bunches. The systematic excitation of all coupled-bunch modes allowed for the first time to determine the damping rates of all 192 eigenmodes of the electron beam. The current dependence of the damping rates was investigated and an instability threshold was found. Besides the investigation of multibunch instabilities, single-bunch instabilities are discussed. In addition, the acquisition unit of the digital feedback system can be triggered on external events. This was used to investigate the injection process and beam losses. It was shown that the transverse feedback system increases the injection efficiency. Another aspect of this thesis is the improvement of the signal quality of ultrashort coherent synchrotron radiation pulses, which are generated by the short-pulse facility at DELTA. The short-pulse facility is based

  16. Einstein Ring in Distant Universe

    Science.gov (United States)

    2005-06-01

    on the newly discovered Einstein ring. The image quality ("seeing") of the R-band image is exceptional (0.5") and the image reveals the lensing system in stunning details. The central dot is the lens, a quiescent massive galaxy that distort the light emitted by background sources. The large arc surrounding the central lens is a part of the Einstein-ring created by a background source finely aligned with the lens. The reddish colour indicates that the redshift of the system is very large. FORS2 spectroscopy of the lensing system yield a redshift close to 1 for the lens (we see the lens as it was when the universe was half its present size), and a record-breaking redshift z=3.8 for a background source of such brightness, hence we see the object (a star forming galaxy) as it was when the universe was only 12% of its present age. The lensing model indicates that the light of the source is magnified at least 13 times. The right panel shows the reconstructed image based on the model of the lens and the source, showing the ring to extend over 3/4 of a circle. "There are only a very few optical rings or arcs known, and even less so in which the lens and the source are at large distance, i.e. more than about 7,000 million light-years away (or half the present age of the Universe)", says Rémi Cabanac, former ESO Fellow and now working at the Canada-France-Hawaii Telescope. "Moreover, very few are nearly complete", he adds. But in the case of this newly found cosmic ring, the images show it to extend to almost 3/4 of a circle. The lensing galaxy is located at a distance of about 8,000 million light-years from us, while the source galaxy whose light is distorted, is much farther away, at 12,000 million light-years. Thus, we see this galaxy as it was when the universe was only 12% of its present age. The lens magnifies the source almost 13 times. The observations reveal the galaxy acting as a lens to be a rather quiet galaxy, 40,000 light-years wide, with an old stellar

  17. Recent Developments of Versatile Photoinitiating Systems for Cationic Ring Opening Polymerization Operating at Any Wavelengths and under Low Light Intensity Sources

    Directory of Open Access Journals (Sweden)

    Jacques Lalevée

    2015-04-01

    Full Text Available Photoinitiators (PI or photoinitiating systems (PIS usable in light induced cationic polymerization (CP and free radical promoted cationic polymerization (FRPCP reactions (more specifically for cationic ring opening polymerization (ROP together with the involved mechanisms are briefly reviewed. The recent developments of novel two- and three-component PISs for CP and FRPCP upon exposure to low intensity blue to red lights is emphasized in details. Examples of such reactions under various experimental conditions are provided.

  18. Recent Developments of Versatile Photoinitiating Systems for Cationic Ring Opening Polymerization Operating at Any Wavelengths and under Low Light Intensity Sources.

    Science.gov (United States)

    Lalevée, Jacques; Mokbel, Haifaa; Fouassier, Jean-Pierre

    2015-04-20

    Photoinitiators (PI) or photoinitiating systems (PIS) usable in light induced cationic polymerization (CP) and free radical promoted cationic polymerization (FRPCP) reactions (more specifically for cationic ring opening polymerization (ROP)) together with the involved mechanisms are briefly reviewed. The recent developments of novel two- and three-component PISs for CP and FRPCP upon exposure to low intensity blue to red lights is emphasized in details. Examples of such reactions under various experimental conditions are provided.

  19. Damping Ring R&D at CESR-TA

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, David L. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics

    2015-01-23

    Accelerators that collide high energy beams of matter and anti-matter are essential tools for the investigation of the fundamental constituents of matter, and the search for new forms of matter and energy. A “Linear Collider” is a machine that would bring high energy and very compact bunches of electrons and positrons (anti-electrons) into head-on collision. Such a machine would produce (among many other things) the newly discovered Higgs particle, enabling a detailed study of its properties. Among the most critical and challenging components of a linear collider are the damping rings that produce the very compact and intense beams of electrons and positrons that are to be accelerated into collision. Hot dilute particle beams are injected into the damping rings, where they are compressed and cooled. The size of the positron beam must be reduced more than a thousand fold in the damping ring, and this compression must be accomplished in a fraction of a second. The cold compact beams are then extracted from the damping ring and accelerated into collision at high energy. The proposed International Linear Collider (ILC), would require damping rings that routinely produce such cold, compact and intense beams. The goal of the Cornell study was a credible design for the damping rings for the ILC. Among the technical challenges of the damping rings; the development of instrumentation that can measure the properties of the very small beams in a very narrow window of time, and mitigation of the forces that can destabilize the beams and prevent adequate cooling, or worse lead to beam loss. One of the most pernicious destabilizing forces is due to the formation of clouds of electrons in the beam pipe. The electron cloud effect is a phenomenon in particle accelerators in which a high density of low energy electrons, build up inside the vacuum chamber. At the outset of the study, it was anticipated that electron cloud effects would limit the intensity of the positron ring

  20. Electronic voting systems for defending free will and resisting bribery and coercion based on ring anonymous signcryption scheme

    Directory of Open Access Journals (Sweden)

    Tsung-Chih Hsiao

    2017-01-01

    Full Text Available Vote by ballot is the feature in a democratic society and the process of decision-making, tending to achieve the philosophy of democratic politics by having the public who are eligible to vote for competent candidates or leaders. With the rapid development of technologies and network applications, electronization has been actively promoted globally during the social transformation period that the concept of electronic voting is further derived. The major advantages of electronic voting, comparing with traditional voting, lie in the mobility strength of electronic voting, reducing a large amount of election costs and enhancing the convenience for the public. Electronic voting allows voters completing voting on the Internet that not only are climate and location restrictions overcome, but the voter turnout is also increased and the voting time is reduced for the public. With the development in the past three decades, electronic voting presents outstanding performance theoretically and practically. Nevertheless, it is regrettable that electronic voting schemes still cannot be completely open because of lures by money and threats. People to lure by money and threats would confirm the voters following their instructions through various methods that more factors would appear on election results, affecting the quality and fairness of the election. In this study, this project aims to design an electronic voting scheme which could actually defend voters’ free will so that lure of money and threats would fail. Furthermore, an electronic voting system based on Elliptic Curve Cryptography is proposed to ensure the efficiency and security, and Ring Signature and Signcryption are applied to reducing the computing costs. Moreover, this project also focuses on applying voting system to mobile devices. As the system efficiency and security are emphasized, voters do not need to participate in the election, but simply complete voting with smart phones, i

  1. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  2. Alternative loop rings

    CERN Document Server

    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

  3. 75 FR 4101 - Enterprise Income Verification (EIV) System User Access Authorization Form and Rules of Behavior...

    Science.gov (United States)

    2010-01-26

    ... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5376-N-05] Enterprise Income Verification (EIV) System User Access Authorization Form and Rules of Behavior and User Agreement AGENCY... Access, Authorization Form and Rules Of Behavior and User Agreement. OMB Approval Number: 2577-New. Form...

  4. Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

    International Nuclear Information System (INIS)

    Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

    1986-01-01

    The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

  5. Broadband feedback systems for the damping of coherent beam instabilities in the stretcher ring ELSA; Breitbandige Feedback-Systeme zur Daempfung kohaerenter Strahlinstabilitaeten am Stretcherring ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Andre

    2012-12-15

    At the Electron Stretcher Facility ELSA an upgrade of the internal beam current up to 200 mA would be desirable in order to increase the intensity of the extracted electron beam for the future experimental hadron physics program. However, such an upgrade is mainly limited by the excitation of coherent beam instabilities in the stretcher ring. As active counteraction, broadband bunch-by-bunch feedback-systems for the longitudinal, as well as for both transverse planes were installed. After detection of the motion of each of the 27 4 stored bunches via beam position monitors, the systems determine independent correction signals for each bunch using digital signal processors. The amplified correction signals are applied to the beam by means of broadband longitudinal and transverse kicker structures. The detailed setup, the commissioning procedure and measurement results of the damping performance of the systems are presented. In addition, the operation of the longitudinal system during the fast energy ramp of 4 GeV/s from 1.2 GeV to 3.2 GeV is investigated.

  6. A canonical form of the equation of motion of linear dynamical systems

    Science.gov (United States)

    Kawano, Daniel T.; Salsa, Rubens Goncalves; Ma, Fai; Morzfeld, Matthias

    2018-03-01

    The equation of motion of a discrete linear system has the form of a second-order ordinary differential equation with three real and square coefficient matrices. It is shown that, for almost all linear systems, such an equation can always be converted by an invertible transformation into a canonical form specified by two diagonal coefficient matrices associated with the generalized acceleration and displacement. This canonical form of the equation of motion is unique up to an equivalence class for non-defective systems. As an important by-product, a damped linear system that possesses three symmetric and positive definite coefficients can always be recast as an undamped and decoupled system.

  7. Cave Rings

    Science.gov (United States)

    2010-10-13

    Carbon Dioxide to form Carbonic acid. • On contact, the acid dissolves the bedrock , normally Calcium Carbonate. • The solution comes into contact with air...parameters have been non-dimensionalized as follows: r → r/λ, a → a/λ, R → R/λ, t → t/σ, where λ2/σ = q/πH. For limestone ( Calcium Carbonate), p is a...a) shows a puddle after 2.25 hrs with the original setup. (b) shows a puddle after 9 hrs, where the sheet has had a thin layer of vegetable oil

  8. Formalized Linear Algebra over Elementary Divisor Rings in Coq

    OpenAIRE

    Cano , Guillaume; Cohen , Cyril; Dénès , Maxime; Mörtberg , Anders; Siles , Vincent

    2016-01-01

    International audience; This paper presents a Coq formalization of linear algebra over elementary divisor rings, that is, rings where every matrix is equivalent to a matrix in Smith normal form. The main results are the formalization that these rings support essential operations of linear algebra, the classification theorem of finitely pre-sented modules over such rings and the uniqueness of the Smith normal form up to multiplication by units. We present formally verified algorithms comput-in...

  9. Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

    Science.gov (United States)

    Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

    2016-06-01

    We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

  10. A novel conversion of C(19)-diterpenoid alkaloids into aconane-type diterpenes with eight-membered ring system via skeletal rearrangement of corresponding diazonium derivatives.

    Science.gov (United States)

    Ji, Hong; Chen, Qiao-Hong; Wang, Feng-Peng

    2009-03-01

    A new and efficient approach toward the conversion of C(19)-diterpenoid alkaloids into diterpenes with [6+8+5+6] ring system is reported. Treatment of imines 5, 14, and 24 derived from the C(19)-diterpenoid alkaloids with NaNO(2)-NaOAc-HOAc afforded a series of novel rearrangement diterpenes 6-8, 15-19, and 25-27, respectively. The lactone 11 was obtained in 41% yield by treating 5 with NaNO(2)-HBr-Br(2). The formation of diazonium intermediate is postulated, which was subsequently subjected to skeletal rearrangement, leading to the enlargement of B ring. All the new compounds were isolated and fully characterized.

  11. Development of high-speed reactive processing system for carbon fiber-reinforced polyamide-6 composite: In-situ anionic ring-opening polymerization

    International Nuclear Information System (INIS)

    Kim, Sang-Woo; Seong, Dong Gi; Yi, Jin-Woo; Um, Moon-Kwang

    2016-01-01

    In order to manufacture carbon fiber-reinforced polyamide-6 (PA-6) composite, we optimized the reactive processing system. The in-situ anionic ring-opening polymerization of ε-caprolactam was utilized with proper catalyst and initiator for PA-6 matrix. The mechanical properties such as tensile strength, inter-laminar shear strength and compressive strength of the produced carbon fiber-reinforced PA-6 composite were measured, which were compared with the corresponding scanning electron microscope (SEM) images to investigate the polymer properties as well as the interfacial interaction between fiber and polymer matrix. Furthermore, kinetics of in-situ anionic ring-opening polymerization of ε-caprolactam will be discussed in the viewpoint of increasing manufacturing speed and interfacial bonding between PA-6 matrix and carbon fiber during polymerization.

  12. Development of high-speed reactive processing system for carbon fiber-reinforced polyamide-6 composite: In-situ anionic ring-opening polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Woo; Seong, Dong Gi; Yi, Jin-Woo; Um, Moon-Kwang [Composites Research Division, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam, 642–831 (Korea, Republic of)

    2016-05-18

    In order to manufacture carbon fiber-reinforced polyamide-6 (PA-6) composite, we optimized the reactive processing system. The in-situ anionic ring-opening polymerization of ε-caprolactam was utilized with proper catalyst and initiator for PA-6 matrix. The mechanical properties such as tensile strength, inter-laminar shear strength and compressive strength of the produced carbon fiber-reinforced PA-6 composite were measured, which were compared with the corresponding scanning electron microscope (SEM) images to investigate the polymer properties as well as the interfacial interaction between fiber and polymer matrix. Furthermore, kinetics of in-situ anionic ring-opening polymerization of ε-caprolactam will be discussed in the viewpoint of increasing manufacturing speed and interfacial bonding between PA-6 matrix and carbon fiber during polymerization.

  13. Ring laser frequency biasing mechanism

    International Nuclear Information System (INIS)

    McClure, R.E.

    1975-01-01

    A ring laser cavity including a magnetically saturable member for differentially phase shifting the contradirectional waves propagating in the laser cavity, the phase shift being produced by the magneto-optic interaction occurring between the light waves and the magnetization in the cavity forming component as the light waves are reflected therefrom is described

  14. Study of the use of methanol-filled Er-doped suspended-core fibres in a temperature-sensing ring laser system

    International Nuclear Information System (INIS)

    Martín, J C; Berdejo, V; Vallés, J A; Sánchez-Martín, J A; Díez, A; Andrés, M V

    2013-01-01

    We report on an experimental/numerical investigation into the use of methanol-filled Er-doped suspended-core fibres (SCFs) in temperature-sensing ring laser systems. We have adopted a ring laser configuration that includes an Er-doped SCF as a temperature-dependent attenuator (TDA) with a step-index Er-doped fibre (EDF) as the laser active medium. The laser performance dependence on the temperature was measured both in continuous wave (CW) and transient regimes. CW laser output power and build-up time values are compared with those of similar laser systems based on other types of Er-doped PCFs or using other laser configurations. A notable variation of 0.73% °C −1 was achieved in CW operation. Then, by means of parameters obtained by numerically fitting the experimental results, the potential sensing performance of the laser configuration with an SCF as a TDA is studied. Moreover, two ring cavity laser configurations (with the SCF acting basically as an attenuator or also as the active media) are compared and the influence of the position of the coupler inside the ring cavity and the contribution of the erbium doping to improve the sensor features are analysed. The longer interaction lengths compatible with laser action using the Er-doped SCF as a TDA could provide variations of laser output power up to 8.6% °C −1 for 90 mW pump power and a 1 m methanol-filled SCF. (paper)

  15. Interaction of Vortex Ring with Cutting Plate

    Science.gov (United States)

    Musta, Mustafa

    2015-11-01

    The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.

  16. The impact of exospheric neutral dynamics on ring current decay

    Science.gov (United States)

    Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.

    2015-12-01

    The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.

  17. Ring Fusion of Fisheye Images Based on Corner Detection Algorithm for Around View Monitoring System of Intelligent Driving

    Directory of Open Access Journals (Sweden)

    Jianhui Zhao

    2018-01-01

    Full Text Available In order to improve the visual effect of the around view monitor (AVM, we propose a novel ring fusion method to reduce the brightness difference among fisheye images and achieve a smooth transition around stitching seam. Firstly, an integrated corner detection is proposed to automatically detect corner points for image registration. Then, we use equalization processing to reduce the brightness among images. And we match the color of images according to the ring fusion method. Finally, we use distance weight to blend images around stitching seam. Through this algorithm, we have made a Matlab toolbox for image blending. 100% of the required corner is accurately and fully automatically detected. The transition around the stitching seam is very smooth, with no obvious stitching trace.

  18. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  19. Second-order Monte Carlo wave-function approach to the relaxation effects on ringing revivals in a molecular system interacting with a strongly squeezed coherent field

    International Nuclear Information System (INIS)

    Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Yamaguchi, Kizashi

    2004-01-01

    We investigate the relaxation effects on the quantum dynamics in a two-state molecular system interacting with a single-mode strongly amplitude-squeezed coherent field using the second-order Monte Carlo wave-function method. The molecular population inversion (collapse-revival behavior of Rabi oscillations) is known to show the echoes after each revival, which are referred to as ringing revivals, in the case of strongly squeezed coherent fields with oscillatory photon-number distributions due to the phase-space interference effect. Two types of relaxation effects, i.e., cavity relaxation (the dissipation of an internal single mode to outer mode) and molecular coherent (phase) relaxation caused by nuclear vibrations on ringing revivals are investigated from the viewpoint of the quantum-phase dynamics using the quasiprobability (Q function) distribution of a single-mode field and the off-diagonal molecular density matrix ρ elec1,2 (t). It turns out that the molecular phase relaxation attenuates both the entire revival-collapse behavior and the increase in ρ elec1,2 (t) during the quiescent region, whereas a very slight cavity relaxation particularly suppresses the echoes in ringing revivals more significantly than the first revival but hardly changes a primary variation in envelope of ρ elec1,2 (t) in the nonrelaxation case

  20. Chaos synchronization and chaotization of complex chaotic systems in series form by optimal control

    International Nuclear Information System (INIS)

    Ge Zhengming; Yang, C.-H.

    2009-01-01

    By the method of quadratic optimum control, a quadratic optimal regulator is used for synchronizing two complex chaotic systems in series form. By this method the least error with less control energy is achieved, and the optimization on both energy and error is realized synthetically. The simulation results of two Quantum-CNN chaos systems in series form prove the effectiveness of this method. Finally, chaotization of the system is given by optimal control.

  1. CHICSi--a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. III. readout system

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, L.; Foerre, G.; Golubev, P.; Jakobsson, B. E-mail: bo.jakobsson@kosufy.lu.se; Kolozhvari, A.; Marciniewski, P.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.; Oestby, J.M

    2004-01-11

    (CHICSi) Celsius Heavy Ion Collaboration Si detector system is a high granularity, modular detector telescope array for operation around the cluster-jet target/circulating beam intersection of the CELSIUS storage ring at the The. Svedberg Laboratory in Uppsala, Sweden. It is able to provide identity and momentum vector of up to 100 charged particles and fragments from proton-nucleus and nucleus-nucleus collisions at intermediate energies, 50-1000A MeV. All detector telescopes as well as the major part of electronic readout system are placed inside the target chamber in ultra-high vacuum (UHV, 10{sup -9}-10{sup -7} Pa). This requires Very Large Scale Integrated (VLSI) microchip for the spectroscopic signal processing and the generation and transport of digital control signals. Eighteen telescopes, read out with chip-on-board technique by ceramics Mother Boards (MB) and corresponding 18 microchips are mounted on a 450x45 mm{sup 2} Grand Mother Board (GMB), processed on FR4 glass-fibre material. Each of these 28 GMB units contains a daisy-chain organisation of the VLSI chips and associated protection circuits. Analogue-to-digital conversion of the spectroscopic signals is performed on a board outside the chamber which is connected on one side to a power distribution board, directly attached to a UHV mounting flange, and on the other side to the VME-based data acquisition system (CHICSiDAQ). This in its turn is connected via a fibre-optic link to the general TSL acquisition system (SVEDAQ), and in this way data from auxiliary detector systems, read out in CAMAC mode, can be stored in coincidence with CHICSi data.

  2. CHICSi--a compact ultra-high vacuum compatible detector system for nuclear reaction experiments at storage rings. III. readout system

    International Nuclear Information System (INIS)

    Carlen, L.; Foerre, G.; Golubev, P.; Jakobsson, B.; Kolozhvari, A.; Marciniewski, P.; Siwek, A.; Veldhuizen, E.J. van; Westerberg, L.; Whitlow, H.J.; Oestby, J.M.

    2004-01-01

    (CHICSi) Celsius Heavy Ion Collaboration Si detector system is a high granularity, modular detector telescope array for operation around the cluster-jet target/circulating beam intersection of the CELSIUS storage ring at the The. Svedberg Laboratory in Uppsala, Sweden. It is able to provide identity and momentum vector of up to 100 charged particles and fragments from proton-nucleus and nucleus-nucleus collisions at intermediate energies, 50-1000A MeV. All detector telescopes as well as the major part of electronic readout system are placed inside the target chamber in ultra-high vacuum (UHV, 10 -9 -10 -7 Pa). This requires Very Large Scale Integrated (VLSI) microchip for the spectroscopic signal processing and the generation and transport of digital control signals. Eighteen telescopes, read out with chip-on-board technique by ceramics Mother Boards (MB) and corresponding 18 microchips are mounted on a 450x45 mm 2 Grand Mother Board (GMB), processed on FR4 glass-fibre material. Each of these 28 GMB units contains a daisy-chain organisation of the VLSI chips and associated protection circuits. Analogue-to-digital conversion of the spectroscopic signals is performed on a board outside the chamber which is connected on one side to a power distribution board, directly attached to a UHV mounting flange, and on the other side to the VME-based data acquisition system (CHICSiDAQ). This in its turn is connected via a fibre-optic link to the general TSL acquisition system (SVEDAQ), and in this way data from auxiliary detector systems, read out in CAMAC mode, can be stored in coincidence with CHICSi data

  3. UV-laser microdissection system - A novel approach for the preparation of high-resolution stable isotope records (δ13C/δ18O) from tree rings

    Science.gov (United States)

    Schollaen, Karina; Helle, Gerhard

    2013-04-01

    Intra-annual stable isotope (δ13C and δ18O) studies of tree rings at various incremental resolutions have been attempting to extract valuable seasonal climatic and environmental information or assessing plant ecophysiological processes. For preparing high-resolution isotope samples normally wood segments or cores are mechanically divided in radial direction or cut in tangential direction. After mechanical dissection, wood samples are ground to a fine powder and either cellulose is extracted or bulk wood samples are analyzed. Here, we present a novel approach for the preparation of high-resolution stable isotope records from tree rings using an UV-laser microdissection system. Firstly, tree-ring cellulose is directly extracted from wholewood cross-sections largely leaving the wood anatomical structure intact and saving time as compared to the classical procedure. Secondly, micro-samples from cellulose cross-sections are dissected with an UV-Laser dissection microscope. Tissues of interest from cellulose cross-sections are identified and marked precisely with a screen-pen and dissected via an UV-laser beam. Dissected cellulose segments were automatically collected in capsules and are prepared for stable isotope (δ13C and δ18O) analysis. The new techniques facilitate inter- and intra-annual isotope analysis on tree-ring and open various possibilities for comparisons with wood anatomy in plant eco-physiological studies. We describe the design and the handling of this novel methodology and discuss advantages and constraints given by the example of intra-annual oxygen isotope analysis on tropical trees.

  4. Does the concept of Clar's aromatic sextet work for dicationic forms of polycyclic aromatic hydrocarbons?--testing the model against charged systems in singlet and triplet states.

    Science.gov (United States)

    Dominikowska, Justyna; Palusiak, Marcin

    2011-07-07

    The concept of Clar's π-electron aromatic sextet was tested against a set of polycyclic aromatic hydrocarbons in neutral and doubly charged forms. Systems containing different types of rings (in the context of Clar's concept) were chosen, including benzene, naphthalene, anthracene, phenanthrene and triphenylene. In the case of dicationic structures both singlet and triplet states were considered. It was found that for singlet state dicationic structures the concept of aromatic sextet could be applied and the local aromaticity could be discussed in the context of that model, whereas in the case of triplet state dicationic structures Clar's model rather failed. Different aromaticity indices based on various properties of molecular systems were applied for the purpose of the studies. The discussion about the interdependence between the values of different aromaticity indices applied to neutral and charged systems in singlet and triplet states is also included. This journal is © the Owner Societies 2011

  5. NRL ion ring program

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.; Golden, J.; Drobot, A.; Mahaffey, R.A.; Marsh, S.J.; Pasour, J.A.

    1977-01-01

    An experiment is under way to form a storng proton ring using the 200 ka, 1.2 MeV, 50 nsec hollow proton beam recently generated at NRL. The 5 m long magnetic field configuration consists of a magnetic cusp, a compressing magnetic field, a gate field and a magnetic mirror. The midplane value of the magnetic mirror is such that the major radius of the ring will be about 10 cm. The degree of field reversal that will be achieved with 5 x 10 16 protons per pulse from the existing beam depends upon the field reversal is possible with the 600 kA proton beam that would be generated from the low inductance coaxial triode coupled to the upgraded Gamble II generator. The propagation and trapping of an intense proton beam in the experimental magnetic field configuration is investigated numerically. The results show that the self magnetic has a very pronounced effect on the dynamics of the gyrating protons

  6. Flexible ring seal

    International Nuclear Information System (INIS)

    Abbes, Claude; Gournier, Andre; Rouaud, Christian; Villepoix, Raymond de.

    1976-01-01

    The invention concerns a flexible metal ring seal, able to ensure a perfect seal between two bearings due to the crushing and elastic deformation properties akin to similar properties in elastomers. Various designs of seal of this kind are already known, particularly a seal made of a core formed by a helical wire spring with close-wound turns and with high axial compression ratio, closed on itself and having the shape of an annulus. This wire ring is surrounded by at least one envelope having at rest the shape of a toroidal surface of which the generating circle does not close on itself. In a particular design mode, the seal in question can include, around the internal spring, two envelopes of which one in contact with the spring is composed of a low ductility elastic metal, such as mild steel or stainless steel and the other is, on the contrary, made of a malleable metal, such as copper or nickel. The first envelope evenly distributes the partial crushing of the spring, when the seal is tightened, on the second envelope which closely fits the two surfaces between which the seal operates. The stress-crushing curve characteristic of the seal comprises two separate parts, the first with a relatively sharp slope corresponds to the start of the seal compression phase, enabling at least some of these curves to reach the requisite seal threshold very quickly, then, beyond this, a second part, practically flat, where the stress is appreciably constant for a wide operating bracket [fr

  7. Birth Control Ring

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

  8. Interactions between motion and form processing in the human visual system

    OpenAIRE

    Mather, G.; Pavan, A.; Bellacosa Marotti, R.; Campana, G.; Casco, C.

    2013-01-01

    The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form proce...

  9. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  10. The generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system

    International Nuclear Information System (INIS)

    Yang Yunqing; Chen Yong

    2009-01-01

    In this paper, we investigate the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system. Firstly, we transform an arbitrary generalized Lorenz system to the generalized Lorenz canonical form, and the relation between the parameter of the generalized Lorenz system and the parameter of the generalized Lorenz canonical form are shown. Secondly, we extend the scheme present by [Yan ZY. Chaos 2005;15:023902] to study the generalized Q-S synchronization between the generalized Lorenz canonical form and the Roessler system, the more general controller is obtained. By choosing different parameter in the generalized controller obtained here, without much extra effort, we can get the controller of synchronization between the Chen system and the Roessler system, the Lue system and the Roessler system, the classic Lorenz system and the Roessler system, the Hyperbolic Lorenz system and the Roessler system, respectively. Finally, numerical simulations are used to perform such synchronization and verify the effectiveness of the controller.

  11. Work Organisation, Forms of Employee Learning and National Systems of Education and Training

    Science.gov (United States)

    Lorenz, Edward; Lundvall, Bengt-Åke; Kraemer-Mbula, Erika; Rasmussen, Palle

    2016-01-01

    This article uses a multi-level framework to investigate for 17 European nations the links between forms of work organisation and style of employee learning at the workplace on the one hand, and the characteristics of national educational and training systems on the other. The analysis shows that forms of work organisation characterised by…

  12. Machining and metrology systems for free-form laser printer mirrors

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    optical systems were designed and manufactured for the individual laser wavelength to be ... The design objective in utilizing a free-form mirror has resulted in a corresponding ... Since mass production of these free-form mirrors is required, the ...

  13. Exploring How Technology Mediates the Types of Relationships Formed in Sociotechnical Systems

    Science.gov (United States)

    Chu, Kar-Hai

    2012-01-01

    This work presents an exploratory study of how technology mediates the different types of relationships that are formed in sociotechnical systems. More people each day are connecting with each other through social networks, online communities, and other forms of virtual environments. Whether for education, information seeking, friendship,…

  14. CCR Certification Form for Wyoming or EPA R8 Tribal Community Water Systems

    Science.gov (United States)

    The CCR Certification Form can be used to certify that community water systems in Wyoming or on Tribal Lands in EPA Region 8 have completed and distributed their annual Consumer Confidence Report (CCR) or water quality report.

  15. Analysis of Fringe Field Formed Inside LDA Measurement Volume Using Compact Two Hololens Imaging Systems

    Science.gov (United States)

    Ghosh, Abhijit; Nirala, A. K.; Yadav, H. L.

    2018-03-01

    We have designed and fabricated four LDA optical setups consisting of aberration compensated four different compact two hololens imaging systems. We have experimentally investigated and realized a hololens recording geometry which is interferogram of converging spherical wavefront with mutually coherent planar wavefront. Proposed real time monitoring and actual fringe field analysis techniques allow complete characterizations of fringes formed at measurement volume and permit to evaluate beam quality, alignment and fringe uniformity with greater precision. After experimentally analyzing the fringes formed at measurement volume by all four imaging systems, it is found that fringes obtained using compact two hololens imaging systems get improved both qualitatively and quantitatively compared to that obtained using conventional imaging system. Results indicate qualitative improvement of non-uniformity in fringe thickness and micro intensity variations perpendicular to the fringes, and quantitative improvement of 39.25% in overall average normalized standard deviations of fringe width formed by compact two hololens imaging systems compare to that of conventional imaging system.

  16. On Noether symmetries and form invariance of mechanico-electrical systems

    International Nuclear Information System (INIS)

    Fu Jingli; Chen Liqun

    2004-01-01

    This Letter focuses on form invariance and Noether symmetries of mechanico-electrical systems. Based on the invariance of Hamiltonian actions for mechanico-electrical systems under the infinitesimal transformation of the coordinates, the electric quantities and the time, the authors present the Noether symmetry transformation, the Noether quasi-symmetry transformation, the generalized Noether quasi-symmetry transformation and the general Killing equations of Lagrange mechanico-electrical systems and Lagrange-Maxwell mechanico-electrical systems. Using the invariance of the differential equations, satisfied by physical quantities, such as Lagrangian, non-potential general forces, under the infinitesimal transformation, the authors propose the definition and criterions of the form invariance for mechanico-electrical systems. The Letter also demonstrates connection between the Noether symmetries and the form invariance of mechanico-electrical systems. An example is designed to illustrate these results

  17. An experiment to study CP violation in the B system using an internal target at the HERA proton ring

    International Nuclear Information System (INIS)

    Hofmann, W.

    1993-03-01

    A group of physicists centered around the ARGUS collaboration got interested in hadron accelerators as a prolific source of B hadrons. The group is presently studying the option of a major-B-physics experiment to be performed at the HERA proton storage ring in fixed target mode using an internal target. Basic goal of the experiment is the detection of CP violation in the 'gold plated' B 0 → J/Ψ K s decay mode, using a dedicated detector triggered on lepton pairs from J/Ψ decay. (orig./HSI)

  18. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

    During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

  19. Client-Oriented Approach: Forming the System of Management of the Bank Relations with Clients

    OpenAIRE

    Zavadska Diana V.

    2015-01-01

    The aim of the article is to develop the theoretical principles of forming the bank relations with clients as part of the client-oriented strategy implementation. As a result of the conducted research there has been presented the definition of client-orientation, mechanism and system of management. The system of management of the bank relations with clients, the purpose and objectives of its formation have been substantiated. The hierarchy of subjects of forming and managing the process...

  20. Non-Linear Dynamics of Saturn’s Rings

    Science.gov (United States)

    Esposito, Larry W.

    2015-11-01

    Non-linear processes can explain why Saturn’s rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. We find that stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, pushing the system across thresholds that lead to persistent states.Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity, and allows aggregates to grow. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit.Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like ‘straw’ that can explain the halo structure and spectroscopy: This requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping at perturbed regions in Saturn’s rings creates both high velocity dispersion and large aggregates at these distances, explaining both small and large particles observed there. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating the Markov chain as an asymmetric random walk with reflecting boundaries allows us to determine the power law index from results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects

  1. Waste form performance assessment in the YUCCA Mountain engineered barrier system, American Nuclear Society

    International Nuclear Information System (INIS)

    Morris, E. E.; Fanning, T. H.; Wigeland, R. A.

    2000-01-01

    This work demonstrates a technique for comparing the performance of waste forms in a repository environment when one or more of the waste forms constitute a small part of the total amount of waste planned for the repository. In applying the technique, it is important to identify radionuclides that are highly soluble in the transport fluid since it is only for these that the release is controlled by the dissolution rate of the waste form matrix. The techniques presented here have been applied to an evaluation of the performance of waste forms from the electrometallurgical treatment of spent fuel in the proposed Yucca Mountain Repository Engineered Barrier System (EBS)

  2. Predicting glass-forming compositions in the Al-La and Al-La-Ni systems

    International Nuclear Information System (INIS)

    Gargarella, P.; de Oliveira, M.F.; Kiminami, C.S.; Pauly, S.; Kuehn, U.; Bolfarini, C.; Botta, W.J.; Eckert, J.

    2011-01-01

    Research highlights: → The glass-forming ability of the Al-La and Al-La-Ni systems was studied using the λ* and the λ.Δe criteria. → Both criteria predicted with just 1% at. of error the best glass-former verified so far in the Al-La system. → Four new glass-former compositions could be predicted in the Al-La-Ni system using the λ.Δe criterion. → The best glass-former reported so far in the Al-La-Ni system was found. - Abstract: In this work, a criterion considering the topological instability (λ) and the differences in the electronegativity of the constituent elements (Δe) was applied to the Al-La and Al-Ni-La systems in order to predict the best glass-forming compositions. The results were compared with literature data and with our own experimental data for the Al-La-Ni system. The alloy described in the literature as the best glass former in the Al-La system is located near the point with local maximum for the λ.Δe criterion. A good agreement was found between the predictions of the λ.Δe criterion and literature data in the Al-La-Ni system, with the region of the best glass-forming ability (GFA) and largest supercooled liquid region (ΔT x ) coinciding with the best compositional region for amorphization indicated by the λ.Δe criterion. Four new glassy compositions were found in the Al-La-Ni system, with the best predicted composition presenting the best glass-forming ability observed so far for this system. Although the λ.Δe criterion needs further refinements for completely describe the glass-forming ability in the Al-La and Al-La-Ni systems, the results demonstrated that this criterion is a good tool to predict new glass-forming compositions.

  3. The quadratic-form identity for constructing the Hamiltonian structure of integrable systems

    International Nuclear Information System (INIS)

    Guo Fukui; Zhang Yufeng

    2005-01-01

    A usual loop algebra, not necessarily the matrix form of the loop algebra A-tilde n-1 , is also made use of for constructing linear isospectral problems, whose compatibility conditions exhibit a zero-curvature equation from which integrable systems are derived. In order to look for the Hamiltonian structure of such integrable systems, a quadratic-form identity is created in the present paper whose special case is just the trace identity; that is, when taking the loop algebra A-tilde 1 , the quadratic-form identity presented in this paper is completely consistent with the trace identity

  4. Reduction and temporary stabilization of Tile C pelvic ring injuries using a posteriorly based external fixation system.

    Science.gov (United States)

    Martin, Murphy P; Rojas, David; Mauffrey, Cyril

    2017-12-05

    Tile C pelvic ring injuries are challenging to manage even in the most experienced hands. The majority of such injuries can be managed using percutaneous reduction techniques, and the posterior ring can be stabilized using percutaneous transiliac-transsacral screw fixation. However, a subgroup of patients present with inadequate bony corridors, significant sacral zone 2 comminution or significant lateral/vertical displacement of the hemipelvis through a complete sacral fracture. Percutaneous strategies in such circumstances can be dangerous. Those patients may benefit from prone positioning and open reduction of the sacral fracture with fixation through tension band plating or lumbo-pelvic fixation. Soft tissue handling is critical, and direct reduction techniques around the sacrum can be difficult due to the complex anatomy and the fragile nature of the sacrum making clamp placement and tightening a challenge. In this paper, we propose a mini-invasive technique of indirect reduction and temporary stabilization, which is soft tissue friendly and permits maintenance of reduction during definitive fixation surgical.

  5. Six-dimensional modeling of coherent bunch instabilities and related freedback systems in storage rings with power-series maps for the lattice

    International Nuclear Information System (INIS)

    Bengtsson, J.; Briggs, D.; Meddahi, M.

    1994-06-01

    The authors have developed 6-dimensional phase-space code that tracks macroparticles for the study of coherent bunch instabilities and related feedback systems. The model is based on power-series maps to represent the lattice, and allows for straightforward inclusion of effects such as amplitude dependent tune shift, chromaticity, synchrotron oscillations, and synchrotron radiation. It simulates long range wake fields such as resistive-wall effects as well as the higher order modes in cavities. The model has served to study the dynamics relevant to the transverse feedback system currently being commissioned for the Advanced Light Source (ALS). Current work integrates earlier versions into a modular system that includes models for transverse and longitudinal feedback systems. It is designed to provide a modular approach to the dynamics and diagnostics, allowing a user to modify the model of a storage ring at run-time without recompilation

  6. Is Student Performance on the Information Systems Analyst Certification Exam Affected by Form of Delivery of Information Systems Coursework?

    Science.gov (United States)

    Haga, Wayne; Moreno, Abel; Segall, Mark

    2012-01-01

    In this paper, we compare the performance of Computer Information Systems (CIS) majors on the Information Systems Analyst (ISA) Certification Exam. The impact that the form of delivery of information systems coursework may have on the exam score is studied. Using a sample that spans three years, we test for significant differences between scores…

  7. The Cryogenic Storage Ring CSR

    OpenAIRE

    von Hahn, Robert; Becker, Arno; Berg, Felix; Blaum, Klaus; Breitenfeldt, Christian; Fadil, Hisham; Fellenberger, Florian; Froese, Michael; George, Sebastian; Göck, Jürgen; Grieser, Manfred; Grussie, Florian; Guerin, Elisabeth A.; Heber, Oded; Herwig, Philipp

    2016-01-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion a...

  8. Simulation of a resonant-type ring magnet power supply with multiple resonant cells and energy storage chokes

    International Nuclear Information System (INIS)

    Kim, J.M.S.; Blackmore, E.W.; Reiniger, K.W.

    1992-01-01

    For the TRIUMF KAON Factory Booster Ring, a resonant-type magnet power supply has been proposed for the dipole magnet excitation. The Booster Ring magnet power supply system based on resonant circuits, coupled with distributed energy make-up networks, is a complex system, sensitive to many system parameters. When multiple resonant cells, each with its own energy make-up network, are connected in a ring, it is very difficult to derive closed-form solutions to determine the operating conditions of the power supply system. A meaningful way to understand and analyze such a complex system is to use a simulation tool. This paper presents the analysis of operating conditions of the resonant-type ring magnet power supply with multiple resonant cells, using the circuit simulation tool, SPICE. The focus of the study is on the effect of circuit parameter variations in energy storage chokes

  9. Phenomenological description of internal friction spectra in glass-forming and glassy systems

    International Nuclear Information System (INIS)

    Lomovskij, V.A.

    1999-01-01

    Dissipative events in different by chemical nature glass-forming systems, including B 2 O 3 , are studied. It is established from the spectra of internal friction of these systems that the maxima of the energy dissipation of the external power impact are positioned both in the area of viscous flow metastable structural liquid state and in the area of solid elastic state

  10. Combined Brillouin light scattering and microwave absorption study of magnon-photon coupling in a split-ring resonator/YIG film system

    Energy Technology Data Exchange (ETDEWEB)

    Klingler, S., E-mail: stefan.klingler@wmi.badw.de; Maier-Flaig, H.; Weiler, M. [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meißner-Straße 8, 85748 Garching (Germany); Physik-Department, Technische Universität München, 85748 Garching (Germany); Gross, R.; Huebl, H.; Goennenwein, S. T. B. [Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Walther-Meißner-Straße 8, 85748 Garching (Germany); Physik-Department, Technische Universität München, 85748 Garching (Germany); Nanosystems Initiative Munich (NIM), 80799 Munich (Germany); Hu, C.-M. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T2N2 (Canada)

    2016-08-15

    Microfocused Brillouin light scattering (BLS) and microwave absorption (MA) are used to study magnon-photon coupling in a system consisting of a split-ring microwave resonator and an yttrium iron garnet (YIG) film. The split-ring resonator is defined by optical lithography and loaded with a 1 μm-thick YIG film grown by liquid phase epitaxy. BLS and MA spectra of the hybrid system are simultaneously recorded as a function of the applied magnetic field magnitude and microwave excitation frequency. Strong coupling of the magnon and microwave resonator modes is found with a coupling strength of g{sub eff} /2π = 63 MHz. The combined BLS and MA data allow us to study the continuous transition of the hybridized modes from a purely magnonic to a purely photonic mode by varying the applied magnetic field and microwave frequency. Furthermore, the BLS data represent an up-conversion of the microwave frequency coupling to optical frequencies.

  11. VEPP-4 electron-positron storage ring RF-system on the base of gyrocon-power SHF-generator with a debunched relativistic beam

    International Nuclear Information System (INIS)

    Budker, G.I.; Gaponov, V.A.; Gorniker, Eh.I.

    1982-01-01

    A gyrocon, SHF-generator, is described in which the energy of debunched relativistic electron beam is converted to the energy of electromagnetic oscillations. The gyrocon is intended for supplying the VEPP-4 accelerating resonators. A high-voltage accelerator is used as an electron source. An electron beam is scanned by a rotating magnetic field of the resonator and in different points of the orbit circumscribed by the beam and is injected into the outlet resonator. The resonator represents a ring-form waveguide with slots for the beam passage. A travelling wave, whose field decelerates electrons, is excited in the resonator tuned in to the scanning frequency, converting the beam power to RF-power which is taken off through the energy outlets. The design parameters of the gyrocon are as follows: electron efficiency > 95%, the general efficiency > 80%, amplification factor 23 dB, output power = 5 MW. Results of preliminary tests of the gyrocon are presented

  12. Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

    Science.gov (United States)

    Buta, Ronald J.

    2017-11-01

    Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

  13. From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

    Science.gov (United States)

    Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

    2018-03-01

    We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

  14. Predictor-based stabilization for chained form systems with input time delay

    Directory of Open Access Journals (Sweden)

    Mnif Faïçal

    2016-12-01

    Full Text Available This note addresses the stabilization problem of nonlinear chained-form systems with input time delay. We first employ the so-called σ-process transformation that renders the feedback system under a linear form. We introduce a particular transformation to convert the original system into a delay-free system. Finally, we apply a state feedback control, which guarantees a quasi-exponential stabilization to all the system states, which in turn converge exponentially to zero. Then we employ the so-called -type control to achieve a quasi-exponential stabilization of the subsequent system. A simulation example illustrated on the model of a wheeled mobile robot is provided to demonstrate the effectiveness of the proposed approach.

  15. ring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  16. Alternatives for high-level waste forms, containers, and container processing systems

    International Nuclear Information System (INIS)

    Crawford, T.W.

    1995-01-01

    This study evaluates alternatives for high-level waste forms, containers, container processing systems, and onsite interim storage. Glass waste forms considered are cullet, marbles, gems, and monolithic glass. Small and large containers configured with several combinations of overpack confinement and shield casks are evaluated for these waste forms. Onsite interim storage concepts including canister storage building, bore holes, and storage pad were configured with various glass forms and canister alternatives. All favorable options include the monolithic glass production process as the waste form. Of the favorable options the unshielded 4- and 7-canister overpack options have the greatest technical assurance associated with their design concepts due to their process packaging and storage methods. These canisters are 0.68 m and 0.54 m in diameter respectively and 4.57 m tall. Life-cycle costs are not a discriminating factor in most cases, varying typically less than 15 percent

  17. Storage ring development at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Krinsky, S.; Bittner, J.; Fauchet, A.M.; Johnson, E.D.; Keane, J.; Murphy, J.; Nawrocky, R.J.; Rogers, J.; Singh, O.V.; Yu, L.H.

    1991-09-01

    This report contains papers on the following topics: Transverse Beam Profile Monitor; Bunch Length Measurements in the VUV Storage Ring; Photoelectric Effect Photon Beam Position Monitors; RF Receivers for Processing Electron Beam Pick-up Electrode Signals; Real-Time Global Orbit Feedback Systems; Local Orbit Feedback; Active Interlock System for High Power Insertion Devices in the X-ray Ring; Bunch Lengthening Cavity for the VUV Ring; SXLS Storage Ring Design

  18. On the use and computation of the Jordan canonical form in system theory

    Science.gov (United States)

    Sridhar, B.; Jordan, D.

    1974-01-01

    This paper investigates various aspects of the application of the Jordan canonical form of a matrix in system theory and develops a computational approach to determining the Jordan form for a given matrix. Applications include pole placement, controllability and observability studies, serving as an intermediate step in yielding other canonical forms, and theorem proving. The computational method developed in this paper is both simple and efficient. The method is based on the definition of a generalized eigenvector and a natural extension of Gauss elimination techniques. Examples are included for demonstration purposes.

  19. Token Ring Project

    Directory of Open Access Journals (Sweden)

    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

  20. Metal-Ligand Cooperative Reactivity in the (pseudo)-Dearomatized PNX(P) Systems: the Influence of the Zwitterionic Form in Dearomatized Pincer Complexes

    KAUST Repository

    Goncalves, Theo

    2017-09-01

    The concept of aromaticity in pincer ligands and complexes was discussed in order to provide insights into their metal-ligand cooperative activities. The aromatic PNx(P) and dearomatized PNx(P)* pincer ligands and the corresponding transition metal complexes were studied with the nucleus-independent chemical shift (NICSzz), anisotropy of the current (induced) density (ACID), isochemical shielding surfaces (ICSSzz), harmonic oscillator model of aromaticity (HOMA), MCBO, Shannon aromaticity, and natural bond order (NBO) analyses. The study on the model systems showed that for the dearomatized species the decrease of the NICS(1)zz value comes with the larger contribution of the aromatic zwitterionic mesomeric form. In all examples, the incorporation of the metal center into the pincer ligand decreases the NICS(1)zz values. The DFT calculations support the dearomatized pyridine ring in PNP* or PNN* ligand indeed being nonaromatic, in contrast to the PN3(P)* ligand which has partial aromatic character due to the larger contribution of the zwitterionic resonance structure. The difference in aromaticity between the rings contributes to the thermodynamic balance of the metal ligand cooperative reactions, changing the energetics of the process when different dearomatized pincer ligands are used. This was further exemplified by aromaticity analysis of the heterolytic hydrogen cleavage reaction of ruthenium PNN complexes of Milstein and the PN3 of Huang, with similar geometries but distinctive thermodynamic preference.

  1. Metal-Ligand Cooperative Reactivity in the (pseudo)-Dearomatized PNX(P) Systems: the Influence of the Zwitterionic Form in Dearomatized Pincer Complexes

    KAUST Repository

    Goncalves, Theo; Huang, Kuo-Wei

    2017-01-01

    The concept of aromaticity in pincer ligands and complexes was discussed in order to provide insights into their metal-ligand cooperative activities. The aromatic PNx(P) and dearomatized PNx(P)* pincer ligands and the corresponding transition metal complexes were studied with the nucleus-independent chemical shift (NICSzz), anisotropy of the current (induced) density (ACID), isochemical shielding surfaces (ICSSzz), harmonic oscillator model of aromaticity (HOMA), MCBO, Shannon aromaticity, and natural bond order (NBO) analyses. The study on the model systems showed that for the dearomatized species the decrease of the NICS(1)zz value comes with the larger contribution of the aromatic zwitterionic mesomeric form. In all examples, the incorporation of the metal center into the pincer ligand decreases the NICS(1)zz values. The DFT calculations support the dearomatized pyridine ring in PNP* or PNN* ligand indeed being nonaromatic, in contrast to the PN3(P)* ligand which has partial aromatic character due to the larger contribution of the zwitterionic resonance structure. The difference in aromaticity between the rings contributes to the thermodynamic balance of the metal ligand cooperative reactions, changing the energetics of the process when different dearomatized pincer ligands are used. This was further exemplified by aromaticity analysis of the heterolytic hydrogen cleavage reaction of ruthenium PNN complexes of Milstein and the PN3 of Huang, with similar geometries but distinctive thermodynamic preference.

  2. Optical control of spin-dependent thermal transport in a quantum ring

    Science.gov (United States)

    Abdullah, Nzar Rauf

    2018-05-01

    We report on calculation of spin-dependent thermal transport through a quantum ring with the Rashba spin-orbit interaction. The quantum ring is connected to two electron reservoirs with different temperatures. Tuning the Rashba coupling constant, degenerate energy states are formed leading to a suppression of the heat and thermoelectric currents. In addition, the quantum ring is coupled to a photon cavity with a single photon mode and linearly polarized photon field. In a resonance regime, when the photon energy is approximately equal to the energy spacing between two lowest degenerate states of the ring, the polarized photon field can significantly control the heat and thermoelectric currents in the system. The roles of the number of photon initially in the cavity, and electron-photon coupling strength on spin-dependent heat and thermoelectric currents are presented.

  3. An investigation of some quantum systems using modified quantization rule form

    Energy Technology Data Exchange (ETDEWEB)

    Maiz, F., E-mail: fethimaiz@gmail.com [University of Cartage, Nabeul Engineering Preparatory Institute, Merazka, 8000 Nabeul (Tunisia); King Khalid University, Faculty of Science, Physics Department, P.O. Box 9004, Abha 61413 (Saudi Arabia)

    2014-09-15

    We propose a new simple quantization rule form: J{sub n}=nπ+δ(n), for exactly solvable and nonsolvable quantum systems. Here, J{sub n} is the momentum integral between two turning points, n the principal quantum number, and δ(n) is a function of potential parameters and n. This new quantization rule form is a generalization of the conventional one, already developed for exactly solvable quantum systems. We found that δ(n) is a constant independent of n for exactly solvable quantum systems. We carry out the expression of δ(n) for V-shape potential, and show that it takes this form δ(n)=(π/2)+(1/a+bn+cn{sup 2}) for anharmonic oscillators potential V(x)=αx{sup p}+βx{sup 2}.

  4. Damping rings for CLIC

    CERN Document Server

    Jowett, John M; Zimmermann, Frank; Owen, H

    2001-01-01

    The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.

  5. Efficient Diethylzinc/Gallic Acid and Diethylzinc/Gallic Acid Ester Catalytic Systems for the Ring-Opening Polymerization of rac-Lactide

    Directory of Open Access Journals (Sweden)

    Karolina Żółtowska

    2015-12-01

    Full Text Available Polylactide (PLA represents one of the most promising biomedical polymers due to its biodegradability, bioresorbability and good biocompatibility. This work highlights the synthesis and characterization of PLAs using novel diethylzinc/gallic acid (ZnEt2/GAc and diethylzinc/propyl gallate (ZnEt2/PGAc catalytic systems that are safe for human body. The results of the ring-opening polymerization (ROP of rac-lactide (rac-LA in the presence of zinc-based catalytic systems have shown that, depending on the reaction conditions, “predominantly isotactic”, disyndiotactic or atactic PLA can be obtained. Therefore, the controlled and stereoselective ROP of rac-LA is discussed in detail in this paper.

  6. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  7. A Closed-Form Technique for the Reliability and Risk Assessment of Wind Turbine Systems

    Directory of Open Access Journals (Sweden)

    Leonardo Dueñas-Osorio

    2012-06-01

    Full Text Available This paper proposes a closed-form method to evaluate wind turbine system reliability and associated failure consequences. Monte Carlo simulation, a widely used approach for system reliability assessment, usually requires large numbers of computational experiments, while existing analytical methods are limited to simple system event configurations with a focus on average values of reliability metrics. By analyzing a wind turbine system and its components in a combinatorial yet computationally efficient form, the proposed approach provides an entire probability distribution of system failure that contains all possible configurations of component failure and survival events. The approach is also capable of handling unique component attributes such as downtime and repair cost needed for risk estimations, and enables sensitivity analysis for quantifying the criticality of individual components to wind turbine system reliability. Applications of the technique are illustrated by assessing the reliability of a 12-subassembly turbine system. In addition, component downtimes and repair costs of components are embedded in the formulation to compute expected annual wind turbine unavailability and repair cost probabilities, and component importance metrics useful for maintenance planning and research prioritization. Furthermore, this paper introduces a recursive solution to closed-form method and applies this to a 45-component turbine system. The proposed approach proves to be computationally efficient and yields vital reliability information that could be readily used by wind farm stakeholders for decision making and risk management.

  8. Adiabatic compression of ion rings

    International Nuclear Information System (INIS)

    Larrabee, D.A.; Lovelace, R.V.

    1982-01-01

    A study has been made of the compression of collisionless ion rings in an increasing external magnetic field, B/sub e/ = zB/sub e/(t), by numerically implementing a previously developed kinetic theory of ring compression. The theory is general in that there is no limitation on the ring geometry or the compression ratio, lambdaequivalentB/sub e/ (final)/B/sub e/ (initial)> or =1. However, the motion of a single particle in an equilibrium is assumed to be completely characterized by its energy H and canonical angular momentum P/sub theta/ with the absence of a third constant of the motion. The present computational work assumes that plasma currents are negligible, as is appropriate for a low-temperature collisional plasma. For a variety of initial ring geometries and initial distribution functions (having a single value of P/sub theta/), it is found that the parameters for ''fat'', small aspect ratio rings follow general scaling laws over a large range of compression ratios, 1 3 : The ring radius varies as lambda/sup -1/2/; the average single particle energy as lambda/sup 0.72/; the root mean square energy spread as lambda/sup 1.1/; and the total current as lambda/sup 0.79/. The field reversal parameter is found to saturate at values typically between 2 and 3. For large compression ratios the current density is found to ''hollow out''. This hollowing tends to improve the interchange stability of an embedded low β plasma. The implications of these scaling laws for fusion reactor systems are discussed

  9. Chiral solitons in spinor polariton rings

    Science.gov (United States)

    Zezyulin, D. A.; Gulevich, D. R.; Skryabin, D. V.; Shelykh, I. A.

    2018-04-01

    We consider theoretically one-dimensional polariton ring accounting for both longitudinal-transverse (TE-TM) and Zeeman splittings of spinor polariton states and spin-dependent polariton-polariton interactions. We present a class of solutions in the form of the localized defects rotating with constant angular velocity and analyze their properties for realistic values of the parameters of the system. We show that the effects of the geometric phase arising from the interplay between the external magnetic field and the TE-TM splitting introduce chirality in the system and make solitons propagating in clockwise and anticlockwise directions nonequivalent. This can be interpreted as a solitonic analog of the Aharonov-Bohm effect.

  10. Electro-optical hybrid slip ring

    Science.gov (United States)

    Hong, En

    2005-11-01

    The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

  11. Quantum Entanglement and Projective Ring Geometry

    Directory of Open Access Journals (Sweden)

    Michel Planat

    2006-08-01

    Full Text Available The paper explores the basic geometrical properties of the observables characterizing two-qubit systems by employing a novel projective ring geometric approach. After introducing the basic facts about quantum complementarity and maximal quantum entanglement in such systems, we demonstrate that the 15 × 15 multiplication table of the associated four-dimensional matrices exhibits a so-far-unnoticed geometrical structure that can be regarded as three pencils of lines in the projective plane of order two. In one of the pencils, which we call the kernel, the observables on two lines share a base of Bell states. In the complement of the kernel, the eight vertices/observables are joined by twelve lines which form the edges of a cube. A substantial part of the paper is devoted to showing that the nature of this geometry has much to do with the structure of the projective lines defined over the rings that are the direct product of n copies of the Galois field GF(2, with n = 2, 3 and 4.

  12. FORMATION OF CENTAURS’ RINGS THROUGH THEIR PARTIAL TIDAL DISRUPTION DURING PLANETARY ENCOUNTERS

    International Nuclear Information System (INIS)

    Hyodo, Ryuki; Charnoz, Sébastien; Genda, Hidenori; Ohtsuki, Keiji

    2016-01-01

    Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20−50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3−6 km s"−"1 and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

  13. Externally controlled anisotropy in pattern-forming reaction-diffusion systems.

    Science.gov (United States)

    Escala, Dario M; Guiu-Souto, Jacobo; Muñuzuri, Alberto P

    2015-06-01

    The effect of centrifugal forces is analyzed in a pattern-forming reaction-diffusion system. Numerical simulations conducted on the appropriate extension of the Oregonator model for the Belousov-Zhabotinsky reaction show a great variety of dynamical behaviors in such a system. In general, the system exhibits an anisotropy that results in new types of patterns or in a global displacement of the previous one. We consider the effect of both constant and periodically modulated centrifugal forces on the different types of patterns that the system may exhibit. A detailed analysis of the patterns and behaviors observed for the different parameter values considered is presented here.

  14. Bosonic and fermionic dipoles on a ring

    DEFF Research Database (Denmark)

    Zöllner, Sascha; Pethick, C. J.; Bruun, Georg Morten

    2011-01-01

    We show that dipolar bosons and fermions confined in a quasi-one-dimensional ring trap exhibit a rich variety of states because their interaction is inhomogeneous. For purely repulsive interactions, with increasing strength of the dipolar coupling there is a crossover from a gaslike state...... to an inhomogeneous crystal-like one. For small enough angles between the dipoles and the plane of the ring, there are regions with attractive interactions, and clustered states can form....

  15. Growth of planetisimals in a gaseous ring

    International Nuclear Information System (INIS)

    Hourigan, K.

    1981-01-01

    The aggregation of planetesimals in a gaseous ring leads to the development of a dominant body amongst the planetesimal population. The presence of the gas in the form of a differentially rotating ring serves to constrain the orbits of the planetesimals and grains to within a thin toroidal region through the action of gas drag. This situation allows for the efficient aggregation of bodies and, as a result of the low resultant relative velocites, the minimization of collisional fragmentation effects

  16. Transformation of nonlinear discrete-time system into the extended observer form

    Science.gov (United States)

    Kaparin, V.; Kotta, Ü.

    2018-04-01

    The paper addresses the problem of transforming discrete-time single-input single-output nonlinear state equations into the extended observer form, which, besides the input and output, also depends on a finite number of their past values. Necessary and sufficient conditions for the existence of both the extended coordinate and output transformations, solving the problem, are formulated in terms of differential one-forms, associated with the input-output equation, corresponding to the state equations. An algorithm for transformation of state equations into the extended observer form is proposed and illustrated by an example. Moreover, the considered approach is compared with the method of dynamic observer error linearisation, which likewise is intended to enlarge the class of systems transformable into an observer form.

  17. CAD system of design and engineering provision of die forming of compressor blades for aircraft engines

    Science.gov (United States)

    Khaimovich, I. N.

    2017-10-01

    The articles provides the calculation algorithms for blank design and die forming fitting to produce the compressor blades for aircraft engines. The design system proposed in the article allows generating drafts of trimming and reducing dies automatically, leading to significant reduction of work preparation time. The detailed analysis of the blade structural elements features was carried out, the taken limitations and technological solutions allowed forming generalized algorithms of forming parting stamp face over the entire circuit of the engraving for different configurations of die forgings. The author worked out the algorithms and programs to calculate three dimensional point locations describing the configuration of die cavity. As a result the author obtained the generic mathematical model of final die block in the form of three-dimensional array of base points. This model is the base for creation of engineering documentation of technological equipment and means of its control.

  18. Form factor of relativistic two-particle system and covariant hamiltonian formulation of quantum field theory

    International Nuclear Information System (INIS)

    Skachkov, N.; Solovtsov, I.

    1979-01-01

    Based on the hamiltonian formulation of quantum field theory proposed by Kadyshevsky the three-dimensional relativistic approach is developed for describing the form factors of composite systems. The main features of the diagram technique appearing in the covariant hamiltonian formulation of field theory are discussed. The three-dimensional relativistic equation for the vertex function is derived and its connection with that for the quasipotential wave function is found. The expressions are obtained for the form factor of the system through equal-time two-particle wave functions both in momentum and relativistic configurational representations. An explicit expression for the form factor is found for the case of two-particle interaction through the Coulomb potential

  19. Relativistic instant-form approach to the structure of two-body composite systems

    International Nuclear Information System (INIS)

    Krutov, A.F.; Troitsky, V.E.

    2002-01-01

    An approach to the electroweak properties of two-particle composite systems is developed. The approach is based on the use of the instant form of relativistic Hamiltonian dynamics. The main feature of this approach is the method of construction of the matrix element of the electroweak current operator. The electroweak current matrix element satisfies the relativistic covariance conditions and in the case of the electromagnetic current also the conservation law automatically. The properties of the system as well as the approximations are formulated in terms of form factors. The approach makes it possible to formulate relativistic impulse approximation in such a way that the Lorentz covariance of the current is ensured. In the electromagnetic case the current conservation law is also ensured. Our approach gives good results for the pion electromagnetic form factor in the whole range of momentum transfers available for experiments at present time, as well as for the lepton decay constant of pions

  20. Functional evidence for alternative ANG II-forming pathways in hamster cardiovascular system

    NARCIS (Netherlands)

    Nishimura, H; Buikema, H; Baltatu, O; Ganten, D; Urata, H

    1998-01-01

    Like human chymase, hamster chymase is an ANG II-forming enzyme, but pathophysiological roles of chymase are still unknown. We determined the functional conversion of ANG I and [Pro(11), D-Ala(12)]ANG I, a chymase-selective substrate, to ANG II in the hamster cardiovascular system. ANG I and

  1. Equilibrium thermodynamics of the ternary membrane-forming system nylon, formic acid and water

    NARCIS (Netherlands)

    Bulte, A.M.W.; Bulte, A.M.W.; Naafs, E.M.; van Eeten, F.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.; Strathmann, H.

    1996-01-01

    The binary Flory-Huggins interaction parameters for the ternary membrane-forming system nylon, formic acid and water have been obtained from literature data, swelling values and melting point depression. Nylon 4,6 nylon 6 and a copolymer of nylon 4,6 and 6 were examined. The isothermal

  2. Forms of Mediation: The Case of Interpreter-Mediated Interactions in Medical Systems

    Science.gov (United States)

    Baraldi, Claudio

    2009-01-01

    This paper analyses the forms of mediation in interlinguistic interactions performed in Italian healthcare services and in contexts of migration. The literature encourages dialogic transformative mediation, empowering participants' voices and changing cultural presuppositions in social systems. It may be doubtful, however, whether mediation can…

  3. Modeling Multiple Human-Automation Distributed Systems using Network-form Games

    Science.gov (United States)

    Brat, Guillaume

    2012-01-01

    The paper describes at a high-level the network-form game framework (based on Bayes net and game theory), which can be used to model and analyze safety issues in large, distributed, mixed human-automation systems such as NextGen.

  4. Traditional medicine as an alternative form of health care system: A ...

    African Journals Online (AJOL)

    Traditional medicine as an alternative form of health care system: A preliminary case study of Nangabo sub-county, central Uganda. ... African Journal of Traditional, Complementary and Alternative Medicines ... The findings indicated that most (43%) respondents derive their livelihoods from traditional medicine practices.

  5. Waste vitrification: prediction of acceptable compositions in a lime-soda-silica glass-forming system

    International Nuclear Information System (INIS)

    Gilliam, T.M.; Jantzen, C.M.

    1996-10-01

    A model is presented based upon calculated bridging oxygens which allows the prediction of the region of acceptable glass compositions for a lime-soda-silica glass-forming system containing mixed waste. The model can be used to guide glass formulation studies (e.g., treatability studies) or assess the applicability of vitrification to candidate waste streams

  6. High resolution computed tomography in patients with various forms of systemic sclerosis

    International Nuclear Information System (INIS)

    Lewszuk, A.; Rozycki, J.; Tarasow, E.; Kowal-Bielecka, O.

    2008-01-01

    Pulmonary lesions are, besides renal and cardiac complications, one of the main causes of mortality among patients with systemic sclerosis (scleroderma). Pathologic changes in the respiratory system take the form of interstitial fibrosis clinically manifested by progressive exertion dyspnea and abnormalities of respiratory restriction type in functional tests. The aim of the study was systematization of pulmonary lesion symptomatology in conventional chest radiography and high resolution computed tomography (HRCT) in patients with various forms of scleroderma, as well as determination of the frequency and localization of the particular lesion types. The study was carried out in a group of 49 patients with systemic sclerosis (47 women and 2 men), who underwent conventional radiography and high resolution computed tomography of the chest. In patients with systemic sclerosis, HRCT revealed most frequently interstitial changes of ground glass type, as well as linear and reticular opacities, whereas bronchiectasis and honeycombing type lesions were less frequent. Pulmonary lesions were seen with increasing frequency towards the lung base and were localized mainly in the posterior, inferior and peripheral parts of the lungs. Comparison of the patients with limited and diffuse scleroderma demonstrated that the diffuse form is associated with more frequent involvement of the respiratory system and more advanced pulmonary lesions. The observed characteristics of pulmonary lesions show similarity between interstitial lung disease in the course of systemic sclerosis and nonspecific interstitial pneumonia (NSIP), which supports classification of interstitial lung disease associated with scleroderma as belonging to that group of interstitial inflammations. (author)

  7. Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

    Science.gov (United States)

    Allegri, G.; Giorleo, L.; Ceretti, E.

    2018-05-01

    Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

  8. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

  9. Dynamical black rings with a positive cosmological constant

    International Nuclear Information System (INIS)

    Kimura, Masashi

    2009-01-01

    We construct dynamical black ring solutions in the five-dimensional Einstein-Maxwell system with a positive cosmological constant and investigate the geometrical structure. The solutions describe the physical process such that a thin black ring at early time shrinks and changes into a single black hole as time increases. We also discuss the multiblack rings and the coalescence of them.

  10. Large scale use of brazing and high temperature brazing for the fabrication of the 6.4 km long vacuum system of the HERA electron storage ring

    International Nuclear Information System (INIS)

    Ballion, R.; Boster, J.; Giesske, W.; Hartwig, H.; Jagnow, D.; Kouptsidis, J.; Pape, R.; Prohl, W.; Schumann, G.; Schwartz, M.; Iversen, K.; Mucklenbeck, J.

    1989-01-01

    The 6.4 km long vacuum system for electrons in the large storage ring HERA at Hamburg consists of about 1,400 components having lengths between .14 and 12 m. The vacuum components are mainly made from variously shaped tubes of the copper alloy CuSn2. This alloy combines sufficient mechanical strength with the high thermal conductivity needed to remove the 6 MW dissipated power of the synchrotron-light. The vacuum components consist additionally of parts made from stainless steel such as flanges, chambers for pumps, beam monitors, etc. All of these parts are connected in a vacuum tight manner and on a large scale by using brazing and high temperature brazing both in a vacuum or in a reducing gas atmosphere. (orig.)

  11. Dichloro-Cycloazatriphosphane: The Missing Link between N2 P2 and P4 Ring Systems in the Systematic Development of NP Chemistry.

    Science.gov (United States)

    Bresien, Jonas; Hinz, Alexander; Schulz, Axel; Suhrbier, Tim; Thomas, Max; Villinger, Alexander

    2017-10-20

    A dichloro-cycloazatriphosphane that incorporates a cyclic NP 3 backbone could be synthesized using knowledge gained from the chemistry of N 2 P 2 and P 4 ring systems. It fills the gap between the congeneric compounds [ClP(μ-NR)] 2 and [ClP(μ-PR)] 2 (R=sterically demanding substituent), and thus contributes to the systematic development of nitrogen-phosphorus chemistry in general. The title compound was studied with respect to its formation via a labile aminodiphosphene, which readily underwent different rearrangement reactions depending on the solvent. All compounds were fully characterized by experimental and computational methods. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Alignment for new Subaru ring

    International Nuclear Information System (INIS)

    Zhang, Ch.; Matsui, S.; Hashimoto, S.

    1999-01-01

    The New SUBARU is a synchrotron light source being constructed at the SPring-8 site. The main facility is a 1.5 GeV electron storage ring that provides light beam in the region from VUV to soft X-ray using SPring-8's 1 GeV linac as an injector. The ring, with a circumference of about 119 meters, is composed of six bending cells. Each bending cell has two normal dipoles of 34 degree and one inverse dipole of -8 degree. The ring has six straight sections: two very long straight sections for a 11-m long undulator and an optical klystron, four short straight sections for a 2.3-m undulator, a super-conducting wiggler, rf cavity and injection, etc. The magnets of the storage ring are composed of 12 dipoles (BMs), 6 invert dipoles (BIs), 56 quadrupoles and 44 sextupoles, etc. For the magnet alignment, positions of the dipoles (the BMs and BIs) are determined by network survey method. The multipoles, which are mounted on girders between the dipoles, are aligned with a laser-CCD camera system. This article presents the methodology used to position the different components and particularly to assure the precise alignment of the multipoles. (authors)

  13. Proton storage ring: man/machine interface

    International Nuclear Information System (INIS)

    Lander, R.F.; Clout, P.N.

    1985-01-01

    The human interface of the Proton Storage Ring Control System at Los Alamos is described in some detail, together with the software environment in which operator interaction programs are written. Some examples of operator interaction programs are given

  14. National synchrotron light source VUV storage ring

    International Nuclear Information System (INIS)

    Blumberg, L.; Bittner, J.; Galayda, J.; Heese, R.; Krinsky, S.; Schuchman, J.; van Steenbergen, A.

    1979-01-01

    A 700 MeV electron storage ring designed for synchrotron radiation applications is described. Lattice and stability calculations are presented and the vacuum, correction and injection systems are discussed

  15. Embryonic origins of a motor system: motor dendrites form a myotopic map in Drosophila.

    Directory of Open Access Journals (Sweden)

    Matthias Landgraf

    2003-11-01

    Full Text Available The organisational principles of locomotor networks are less well understood than those of many sensory systems, where in-growing axon terminals form a central map of peripheral characteristics. Using the neuromuscular system of the Drosophila embryo as a model and retrograde tracing and genetic methods, we have uncovered principles underlying the organisation of the motor system. We find that dendritic arbors of motor neurons, rather than their cell bodies, are partitioned into domains to form a myotopic map, which represents centrally the distribution of body wall muscles peripherally. While muscles are segmental, the myotopic map is parasegmental in organisation. It forms by an active process of dendritic growth independent of the presence of target muscles, proper differentiation of glial cells, or (in its initial partitioning competitive interactions between adjacent dendritic domains. The arrangement of motor neuron dendrites into a myotopic map represents a first layer of organisation in the motor system. This is likely to be mirrored, at least in part, by endings of higher-order neurons from central pattern-generating circuits, which converge onto the motor neuron dendrites. These findings will greatly simplify the task of understanding how a locomotor system is assembled. Our results suggest that the cues that organise the myotopic map may be laid down early in development as the embryo subdivides into parasegmental units.

  16. Interactions between motion and form processing in the human visual system.

    Science.gov (United States)

    Mather, George; Pavan, Andrea; Bellacosa Marotti, Rosilari; Campana, Gianluca; Casco, Clara

    2013-01-01

    The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However, recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by "motion-streaks" influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus, form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS.

  17. Interactions between motion and form processing in the human visual system

    Directory of Open Access Journals (Sweden)

    George eMather

    2013-05-01

    Full Text Available The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by ‘motion-streaks’ influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS.

  18. Off-Line Testing of Tribo-Systems for Sheet Metal Forming Production

    DEFF Research Database (Denmark)

    Bay, Niels; Ceron, Ermanno

    2014-01-01

    Off-line testing of new tribo-systems for sheet metal forming production is an important issue, when new, environmentally benign lubricants are to be introduced. To obtain useful results it is, however, vital to ensure similar conditions as in the production process regarding the main tribo...... leading to very high tool/workpiece interface pressure and temperature in the second re-draw. Under such conditions only the best lubricant systems work satisfactory, and the paper shows how the performance of different tribo-systems in production may be predicted by off-line testing combined...

  19. Row Reduced Echelon Form for Solving Fully Fuzzy System with Unknown Coefficients

    Directory of Open Access Journals (Sweden)

    Ghassan Malkawi

    2014-08-01

    Full Text Available This study proposes a new method for finding a feasible fuzzy solution in positive Fully Fuzzy Linear System (FFLS, where the coefficients are unknown. The fully fuzzy system is transferred to linear system in order to obtain the solution using row reduced echelon form, thereafter; the crisp solution is restricted in obtaining the positive fuzzy solution. The fuzzy solution of FFLS is included crisp intervals, to assign alternative values of unknown entries of fuzzy numbers. To illustrate the proposed method, numerical examples are solved, where the entries of coefficients are unknown in right or left hand side, to demonstrate the contributions in this study.

  20. The "Good, Bad and Ugly" pin site grading system: A reliable and memorable method for documenting and monitoring ring fixator pin sites.

    Science.gov (United States)

    Clint, S A; Eastwood, D M; Chasseaud, M; Calder, P R; Marsh, D R

    2010-02-01

    Although there is much in the literature regarding pin site infections, there is no accepted, validated method for documenting their state. We present a system for reliably labelling pin sites on any ring fixator construct and an easy-to-remember grading system to document the state of each pin site. Each site is graded in terms of erythema, pain and discharge to give a 3-point scale, named "Good", "Bad" and "Ugly" for ease of recall. This system was tested for intra- and inter-observer reproducibility. 15 patients undergoing elective limb reconstruction were recruited. A total of 218 pin sites were independently scored by 2 examiners. 82 were then re-examined later by the same examiners. 514 pin sites were felt to be "Good", 80 "Bad" and 6 "Ugly". The reproducibility of the system was found to be excellent. We feel our system gives a quick, reliable and reproducible method to monitor individual pin sites and their response to treatment. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.