WorldWideScience

Sample records for winding coil groups

  1. Superconducting Coil Winding Machine Control System

    Energy Technology Data Exchange (ETDEWEB)

    Nogiec, J. M. [Fermilab; Kotelnikov, S. [Fermilab; Makulski, A. [Fermilab; Walbridge, D. [Fermilab; Trombly-Freytag, K. [Fermilab

    2016-10-05

    The Spirex coil winding machine is used at Fermilab to build coils for superconducting magnets. Recently this ma-chine was equipped with a new control system, which al-lows operation from both a computer and a portable remote control unit. This control system is distributed between three layers, implemented on a PC, real-time target, and FPGA, providing respectively HMI, operational logic and direct controls. The system controls motion of all mechan-ical components and regulates the cable tension. Safety is ensured by a failsafe, redundant system.

  2. An automated coil winding machine for the SSC dipole magnets

    International Nuclear Information System (INIS)

    Kamiya, S.; Iwase, T.; Inoue, I.; Fukui, I.; Ishida, K.; Kashiwagi, S.; Sato, Y.; Yoshihara, T.; Yamamoto, S.; Johnson, E.; Gibson, C.

    1990-01-01

    The authors have finished the preliminary design of a fully automated coil winding machine that can be used to manufacture the large number of SSC dipole magnets. The machine aims to perform all coil winding operations including coil parts inserting without human operators at a high productive rate. The machine is composed of five industrial robots. In order to verify the design, they built a small winding machine using an industrial robot and successfully wound a 1 meter long coil using SSC dipole magnet wire. The basic design for the full length coil and the robot winding technique are described in this paper. A fully automated coil winding machine using standard industrial components would be very useful if duplicate production lines are used. 5 figs., 1 tab

  3. Design of the pancake-winding central solenoid coil

    International Nuclear Information System (INIS)

    Yoshida, Kiyoshi; Nishi, Masataka; Tsuji, Hirosi

    1995-01-01

    There was a debate over whether a pancake-winding or layer-winding technique is more appropriate for the Central Solenoid (CS) coil for ITER superconducting magnet. The layer-winding CS has the advantage of homogeneous winding supporting the TF centering force without weak joints, but has many difficulties during manufacturing and quality control. On other hand, the pancake-winding has the advantage of better quality control during manufacturing and module testing but has difficulties with joints and feeders, and pipes located in the load path of the bucking force from the toroidal field coils. The compact joints, reinforcement by preformed amour, sharp bending, and double seals are applied to the design of pancake-winding CS coil and demonstrated by hardware developments. The pancake-winding CS coil by using modified existing technology is compatible with the bucking concept of the ITER magnet system. (author)

  4. A general winding law of modular stellarator coils

    International Nuclear Information System (INIS)

    Harmeyer, E.; Kisslinger, J.; Rau, F.; Wobig, H.

    1985-03-01

    A general winding law for twisted coils is described in terms of analytic functions. On a toroidal surface given as x vector = x vector (φ,Θ) (φ = toroidal coordinate, Θ = poloidal coordinate) the current filaments φ = φ κ (Θ) are represented in terms of sin-functions. The paper includes several examples of classical stellarator and HELIAC configurations. By specifying a separate winding law for every single coil also WVII-AS type configurations can be modelled. The numerical code describing the central filament and the borderlines of the coils are given in the appendix. (orig.)

  5. New method to design stellarator coils without the winding surface

    Science.gov (United States)

    Zhu, Caoxiang; Hudson, Stuart R.; Song, Yuntao; Wan, Yuanxi

    2018-01-01

    Finding an easy-to-build coils set has been a critical issue for stellarator design for decades. Conventional approaches assume a toroidal ‘winding’ surface, but a poorly chosen winding surface can unnecessarily constrain the coil optimization algorithm, This article presents a new method to design coils for stellarators. Each discrete coil is represented as an arbitrary, closed, one-dimensional curve embedded in three-dimensional space. A target function to be minimized that includes both physical requirements and engineering constraints is constructed. The derivatives of the target function with respect to the parameters describing the coil geometries and currents are calculated analytically. A numerical code, named flexible optimized coils using space curves (FOCUS), has been developed. Applications to a simple stellarator configuration, W7-X and LHD vacuum fields are presented.

  6. Manufacturing Development of the NCSX Modular Coil Windings

    International Nuclear Information System (INIS)

    Chrzanowski, JH; Fogarty, PJ; Heitzenroeder, PJ; Meighan, T.; Nelson, B.; Raftopoulos, S.; Williamson, D.

    2005-01-01

    The modular coils on the National Compact Stellarator Experiment (NCSX) present a number of significant engineering challenges due to their complex shapes, requirements for high dimensional accuracy and the high current density required in the modular coils due to space constraints. In order to address these challenges, an R and D program was established to develop the conductor, insulation scheme, manufacturing techniques, and procedures. A prototype winding named Twisted Racetrack Coil (TRC) was of particular importance in dealing with these challenges. The TRC included a complex shaped winding form, conductor, insulation scheme, leads and termination, cooling system and coil clamps typical of the modular coil design. Even though the TRC is smaller in size than a modular coil, its similar complex geometry provided invaluable information in developing the final design, metrology techniques and development of manufacturing procedures. In addition a discussion of the development of the copper rope conductor including ''Keystoning'' concerns; the epoxy impregnation system (VPI) plus the tooling and equipment required to manufacture the modular coils will be presented

  7. Illinois Wind Workers Group

    Energy Technology Data Exchange (ETDEWEB)

    David G. Loomis

    2012-05-28

    The Illinois Wind Working Group (IWWG) was founded in 2006 with about 15 members. It has grown to over 200 members today representing all aspects of the wind industry across the State of Illinois. In 2008, the IWWG developed a strategic plan to give direction to the group and its activities. The strategic plan identifies ways to address critical market barriers to the further penetration of wind. The key to addressing these market barriers is public education and outreach. Since Illinois has a restructured electricity market, utilities no longer have a strong control over the addition of new capacity within the state. Instead, market acceptance depends on willing landowners to lease land and willing county officials to site wind farms. Many times these groups are uninformed about the benefits of wind energy and unfamiliar with the process. Therefore, many of the project objectives focus on conferences, forum, databases and research that will allow these stakeholders to make well-educated decisions.

  8. A continuous winding scheme for superconducting tokamak coils with cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Kim, Sang-ho; Chung, Kie-hyung; Lee, Deok Kyo

    2001-01-01

    Superconducting magnet coils are essential for steady-state or long-pulse operation of tokamaks. In an advanced tokamak, the central solenoid (CS) coils are usually divided into several pairs of modules to provide for an extra plasma shaping capability in addition to those available from the shaping (poloidal field) coils. In the conventional pancake winding scheme of superconducting coils, each coil consists of separate superconducting 'double-pancake' coils connected together in series; however, such joints are not superconducting, which is one of the major disadvantages, especially in pulsed operations. A new type of winding was adopted for the ITER CS coil, which consists of cylindrical shell 'layers' joined in series. A disadvantage of this layer winding is its inability to yield modular coils that can provide certain degree of plasma shaping. Joints can be removed in a coil winding pack with the conventional pancake winding scheme, if the conductor is sufficiently long and the winding machine is properly equipped. The compactness, however, cannot be preserved with this scheme. The winding compactness is important since the radial build of the CS coils is one of the major parameters that determine the machine size. In this paper, we present a continuous winding scheme that requires no joints, allows coil fabrication at minimum dimension, and meets the flux swing requirement and other practical aspects

  9. Method of eliminating the training effect in superconducting coils by post-wind preload

    International Nuclear Information System (INIS)

    Heim, J.R.

    1976-01-01

    The training effect in superconducting coils is eliminated by winding the coil with a composite material that includes both a superconductor and a normal material. Stresses are applied to the wound coil in the direction that electromagnetic stresses will be applied to the coil during normal use. The applied stresses are greater than the calculated magnitude of the greatest electromagnetic stresses to be applied to the coil

  10. Development of Ground Coils with Low Eddy Current Loss by Applying the Compression Molding Method after the Coil Winding

    Science.gov (United States)

    Suzuki, Masao; Aiba, Masayuki; Takahashi, Noriyuki; Ota, Satoru; Okada, Shigenori

    In a magnetically levitated transportation (MAGLEV) system, a huge number of ground coils will be required because they must be laid for the whole line. Therefore, stable performance and reduced cost are essential requirements for the ground coil development. On the other hand, because the magnetic field changes when the superconducting magnet passes by, an eddy current will be generated in the conductor of the ground coil and will result in energy loss. The loss not only increases the magnetic resistance for the train running but also brings an increase in the ground coil temperature. Therefore, the reduction of the eddy current loss is extremely important. This study examined ground coils in which both the eddy current loss and temperature increase were small. Furthermore, quantitative comparison for the eddy current loss of various magnet wire samples was performed by bench test. On the basis of the comparison, a round twisted wire having low eddy current loss was selected as an effective ground coil material. In addition, the ground coils were manufactured on trial. A favorable outlook to improve the size accuracy of the winding coil and uneven thickness of molded resin was obtained without reducing the insulation strength between the coil layers by applying a compression molding after winding.

  11. Coiled-Coil Irregularities and Instabilities in Group A Streptococcus M1 Are Required for Virulence

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, Case; Zinkernagel, Annelies S.; Macheboeuf, Pauline; Cunningham, Madeleine W.; Nizet, Victor; Ghosh, Partho (UO-HSC); (UCSD)

    2008-07-21

    Antigenically variable M proteins are major virulence factors and immunogens of the human pathogen group A Streptococcus (GAS). Here, we report the -3 angstrom resolution structure of a GAS M1 fragment containing the regions responsible for eliciting type-specific, protective immunity and for binding fibrinogen, which promotes M1 proinflammatory and antiphagocytic functions. The structure revealed substantial irregularities and instabilities throughout the coiled coil of the M1 fragment. Similar structural irregularities occur in myosin and tropomyosin, explaining the patterns of cross-reactivity seen in autoimmune sequelae of GAS infection. Sequence idealization of a large segment of the M1 coiled coil enhanced stability but diminished fibrinogen binding, proinflammatory effects, and antibody cross-reactivity, whereas it left protective immunogenicity undiminished. Idealized M proteins appear to have promise as vaccine immunogens.

  12. Design Aspects on Winding of an MgB2 Superconducting Generator Coil

    DEFF Research Database (Denmark)

    Magnusson, N.; Eliassen, J.C.; Abrahamsen, Asger Bech

    2015-01-01

    by the thickness of the turn-to-turn electrical insulation. Here we discuss the impact of the insulation and suggest the use of a one-step winding process, employing wet-winding, where the applied epoxy also constitutes the insulation layer between turns. In this way the coil is densified by approximately 10......% compared to the use of an additional, dedicated, electrical insulation like Kapton for wet-winding or glass-fibre for dry-winding followed by vacuum impregnation. We show the results of a trial winding of 500 m of MgB2 superconducting wire into a double pancake coil using the wet-winding technique...

  13. A Thermal Performance Analysis and Comparison of Fiber Coils with the D-CYL Winding and QAD Winding Methods

    Directory of Open Access Journals (Sweden)

    Xuyou Li

    2016-06-01

    Full Text Available The thermal performance under variable temperature conditions of fiber coils with double-cylinder (D-CYL and quadrupolar (QAD winding methods is comparatively analyzed. Simulation by the finite element method (FEM is done to calculate the temperature distribution and the thermal-induced phase shift errors in the fiber coils. Simulation results reveal that D-CYL fiber coil itself has fragile performance when it experiences an axially asymmetrical temperature gradient. However, the axial fragility performance could be improved when the D-CYL coil meshes with a heat-off spool. Through further simulations we find that once the D-CYL coil is provided with an axially symmetrical temperature environment, the thermal performance of fiber coils with the D-CYL winding method is better than that with the QAD winding method under the same variable temperature conditions. This valuable discovery is verified by two experiments. The D-CYL winding method is thus promising to overcome the temperature fragility of interferometric fiber optic gyroscopes (IFOGs.

  14. DESIGN, FABRICATION AND TEST OF THE REACT AND WIND, NB(3)SN, LDX FLOATING COIL CONDUCTOR

    International Nuclear Information System (INIS)

    SMITH, B.A.; MICHAEL, P.C.; MINERVINI, J.V.; TAKAYASU, M.; SCHULTZ, J.H.; GREGORY, E.; PYON, T.; SAMPSON, W.B.; GHOSH, A.; SCANLAN, R.

    2000-01-01

    The Levitated Dipole Experiment (LDX) is a novel approach for studying magnetic confinement of a fusion plasma. In this approach, a superconducting ring coil is magnetically levitated for up to 8 hours a day in the center of a 5 meter diameter vacuum vessel. The levitated coil, with on-board helium supply, is called the gloating Coil (F-Coil). Although the maximum field at the coil is only 5.3 tesla, a react-and-wind Nb 3 Sn conductor was selected because the relatively high critical temperature will enable the coil to remain levitated while it warms from 5 K to 10 K. Since pre-reacted Nb 3 Sn tape is no longer commercially available, a composite conductor was designed that contains an 18 strand Nb 3 Sn Rutherford cable. The cable was reacted and then soldered into a structural copper channel that completes the conductor and also provides quench protection. The strain state of the cable was continuously controlled during fabrication steps such as: soldering into the copper channel, spooling, and coil winding, to prevent degradation of the critical current. Measurements of strand and cable critical currents are reported, as well as estimates of the effect of fabrication, winding and operating strains on critical current

  15. Coiled-coil destabilizing residues in the group A Streptococcus M1 protein are required for functional interaction.

    Science.gov (United States)

    Stewart, Chelsea M; Buffalo, Cosmo Z; Valderrama, J Andrés; Henningham, Anna; Cole, Jason N; Nizet, Victor; Ghosh, Partho

    2016-08-23

    The sequences of M proteins, the major surface-associated virulence factors of the widespread bacterial pathogen group A Streptococcus, are antigenically variable but have in common a strong propensity to form coiled coils. Paradoxically, these sequences are also replete with coiled-coil destabilizing residues. These features are evident in the irregular coiled-coil structure and thermal instability of M proteins. We present an explanation for this paradox through studies of the B repeats of the medically important M1 protein. The B repeats are required for interaction of M1 with fibrinogen (Fg) and consequent proinflammatory activation. The B repeats sample multiple conformations, including intrinsically disordered, dissociated, as well as two alternate coiled-coil conformations: a Fg-nonbinding register 1 and a Fg-binding register 2. Stabilization of M1 in the Fg-nonbinding register 1 resulted in attenuation of Fg binding as expected, but counterintuitively, so did stabilization in the Fg-binding register 2. Strikingly, these register-stabilized M1 proteins gained the ability to bind Fg when they were destabilized by a chaotrope. These results indicate that M1 stability is antithetical to Fg interaction and that M1 conformational dynamics, as specified by destabilizing residues, are essential for interaction. A "capture-and-collapse" model of association accounts for these observations, in which M1 captures Fg through a dynamic conformation and then collapses into a register 2-coiled coil as a result of stabilization provided by binding energy. Our results support the general conclusion that destabilizing residues are evolutionarily conserved in M proteins to enable functional interactions necessary for pathogenesis.

  16. Fabrication of new joints for SST-1 TF coil winding packs

    International Nuclear Information System (INIS)

    Prasad, Upendra; Sharma, A.N.; Patel, Dipak; Doshi, Kalpesh; Khristi, Yohan; Varmora, Pankaj; Chauhan, Pradeep; Jadeja, S.J.; Gupta, Pratibha; Pradhan, S.

    2013-01-01

    Highlights: • We have carried out work related with sub-nanoohm joints for superconducting Tokamak winding packs. • We have established fine tune QA/QC procedures for sub-nanoohm joints fabrication. • We have optimised welding parameters for cable in conduit conductors for fusion relevant magnets. • We have established precised measurement data acquisition system for low resistance measurements at cryogenic temperature. -- Abstract: The Toroidal Field (TF) magnet system of SST-1 has sixteen NbTi/Cu based coils with about one hundred Inter-Pancake (IP) and Inter-Coil (IC) joints. New box type helium leak tight, low DC resistance joints have been designed, fabricated and tested at 5 K temperature and 10 kA DC transport current. The prototype of this joint has been validated in laboratory as well as on spare TF coil winding pack. Moreover, the performance of these joints has been realised and validated on actual sixteen TF winding packs, the joint resistance of ∼0.5 nΩ repeatedly measured on hundreds of IP joints. The quality of terminations and joints was ensured at various stages of fabrication. The quality of joint box material was ensured by visual inspection, chemical analysis, radiography test, ultrasonic test, eddy current test, etc. This paper describes joint design drivers, joint design detail, prototype joint fabrication processes, quality assurance (QA)/quality control (QC) adopted during prototype and actual joint fabrication process, joint resistance measurement on actual TF coils and analysis of measured joint resistance in detail

  17. WInd-and-react Bi-2212 coil development for accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, A.; Acosta, P.; Cheng, D.; Dietderich, D. R.; Mentink, M. G. T.; Prestemon, S. O.; Meinesz, M.; Hong, S.; Huang, Y.; Miao, H.; Parrell, J.; Sabbi, G.L.

    2009-10-13

    Sub-scale coils are being manufactured and tested at Lawrence Berkeley National Laboratory in order to develop wind-and-react Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (Bi-2212) magnet technology for future graded accelerator magnet use. Previous Bi-2212 coils showed significant leakage of the conductors core constituents to the environment, which can occur during the partial melt reaction around 890 C in pure oxygen. The main origin of the observed leakage is intrinsic leakage of the wires, and the issue is therefore being addressed at the wire manufacturing level. We report on further compatibility studies, and the performance of new sub-scale coils that were manufactured using improved conductors. These coils exhibit significantly reduced leakage, and carry currents that are about 70% of the witness wire critical current (I{sub c}). The coils demonstrate, for the first time, the feasibility of round wire Bi-2212 conductors for accelerator magnet technology use. Successful high temperature superconductor coil technology will enable the manufacture of graded accelerator magnets that can surpass the, already closely approached, intrinsic magnetic field limitations of Nb-based superconducting magnets.

  18. Liquid Crystalline Assembly of Coil-Rod-Coil Molecules with Lateral Methyl Groups into 3-D Hexagonal and Tetragonal Assemblies

    Science.gov (United States)

    Wang, Zhuoshi; Lan, Yu; Zhong, Keli; Liang, Yongri; Chen, Tie; Jin, Long Yi

    2014-01-01

    In this paper, we report the synthesis and self-assembly behavior of coil-rod-coil molecules, consisting of three biphenyls linked through a vinylene unit as a conjugated rod segment and poly(ethylene oxide) (PEO) with a degree of polymerization (DP) of 7, 12 and 17, incorporating lateral methyl groups between the rod and coil segments as the coil segment. Self-organized investigation of these molecules by means of differential scanning calorimetry (DSC), thermal polarized optical microscopy (POM) and X-ray diffraction (XRD) reveals that the lateral methyl groups attached to the surface of rod and coil segments, dramatically influence the self-assembling behavior in the liquid-crystalline mesophase. Molecule 1 with a relatively short PEO coil length (DP = 7) self-assembles into rectangular and oblique 2-dimensional columnar assemblies, whereas molecules 2 and 3 with DP of 12 and 17 respectively, spontaneously self-organize into unusual 3-dimensional hexagonal close-packed or body-centered tetragonal assemblies. PMID:24699045

  19. Inside anti-wind groups

    International Nuclear Information System (INIS)

    Rap, C.

    2010-01-01

    At the beginning the opposition to wind turbines was based on the preservation of the landscape. Now as wind farms are more frequent, the reasons to fight them become more concrete: -) the loss of value of properties due to the installation of a wind turbine in the surroundings, -) the noise and the view, or -) the impact on the fauna. More and more people question the choice of wind power as an efficient and reliable source of energy. In France about a few tens of thousand people are registered in associations of opponents to wind energy. These associations have merged into 2 main federations: 'Vent de colere' and 'Federation Environement Durable'. In october 2008 Apaw, a European platform against wind energy, was founded. Apaw gathers 400 federations from 21 European countries. Wind energy opponents are getting momentum, they are becoming experts on how to communicate, how to organize demonstrations, how to take legal actions and on active lobbying. (A.C.)

  20. Winding machines for the manufacturing of superconductive coils of the main European fusion research machines

    CERN Document Server

    Cazzaniga, R; D’Urzo, C

    2005-01-01

    The successfull construction of large magnets passes through the development and application of non-conventional manufacturing processes. A difficult and delicate step in the manufacturing of superconducting coils is the conductor winding technique. It is often a challenging and technologically advanced process, developed according to the requirements of each project. An important aspect during the winding is to avoid any deformation of the cable cross section leading to a damage of the strands and to maintain the design features of the cable. A second aspect is to assure the suitable repeatability and a production rate for an industrial process. The winding line is a system of different machines linked and tuned together properly designed for each project. An adapted software assures the overall process control. TPA realized for ANSALDO Superconduttori the winding lines for many projects: TFMC (NET-TEAM), CMS (INFN-CERN), WENDELSTEIN W7-X (Max Planck Institute, IPP), etc. The experience acquired in this fiel...

  1. LCT-coil design: Mechanical interaction between composite winding and steel casing under various test conditions

    International Nuclear Information System (INIS)

    Dolensky, B.; Messemer, G.; Zehlein, H.; Erb, J.

    1981-01-01

    Finite element computations for the structural design of the large superconducting toroidal field coil contributed by EURATOM to the Large Coil Test Facility (LCTF) at ORNL, USA were performed at KfK, using the ASKA code. The layout of the coil must consider different types of requirements: firstly, an optimal D-shaped contour minimizing circumferential stress gradients under normal operation in the toroidal arrangement must be defined. Secondly, the three-dimensional real design effects due to the actual support conditions, manufacturing tolerances etc. must be mastered for different basic operational and failure load cases. And, thirdly, the design must stand a single coil qualification test in the TOSKA-facility at KfK, Karlsruhe, FRG, before it is plugged into the LCTF. The emphasis of the paper is three-pronged according to these requirements: i) the 3D magnetic body forces as well as the underlying magnetic fields as computed by the HEDO-code are described. ii) The mechanical interaction between casing and winding as given elsewhere in terms of high stress regions, gaps, slide movements and contact forces for various load cases representing the LCTF test conditions is illustrated here by a juxtaposition of the operational deformations and stresses within the LCTF and the TOSKA. iii) Particular effects like the restraint imposed by a corset-type reinforcement of the coil in the TOSKA test facility to limit the breathing deformation are parametrically studied. Moreover, the possibilities to derive scaling laws which make essential results transferable to larger coils by extracting a 1D mechanical response from the 3D finite element model is also demonstrated. (orig./GG)

  2. The mechanism of thermal runaway due to continuous local disturbances in the YBCO-coated conductor coil winding

    International Nuclear Information System (INIS)

    Yanagisawa, Y; Okuyama, E; Takematsu, T; Takizawa, A; Takahashi, M; Maeda, H; Nakagome, H; Takao, T; Hamada, M; Matsumoto, S; Kiyoshi, T

    2012-01-01

    Though YBCO coils are stable against transient disturbances such as conductor motion, they suffer from thermal runaway at a current below the coil critical current due to continuous local disturbances attributed to partial degradation of the conductor in the coil winding. Continuous heat generation in the degraded layer induces thermal runaway in adjacent layers; thermal runaway does not occur in the degraded layer spontaneously due to the small n index of the degraded YBCO-coated conductor. The thermal runaway current depends on the cooling conditions of the winding. For a paraffin-impregnated YBCO coil under quasi-adiabatic conditions, the thermal runaway current is far below the coil critical current, while it is close to the coil critical current in the case of a dry-wound coil. The permissible temperature rise following a thermal runaway for YBCO conductors in the degraded layer is demonstrated to be 340 K. If the YBCO coils are operated at a temperature below 20 K, the current density, typically 600–800 A mm −2 , is much higher than that at 77 K. Therefore, the time interval between thermal runaway initiation and the melting temperature becomes less than 0.5 s, posing a difficult problem for protection; i.e., thermal runaway due to continuous local disturbances is hazardous to the safe operation of high current density YBCO coils. (paper)

  3. Brillouin Corrosion Expansion Sensors for Steel Reinforced Concrete Structures Using a Fiber Optic Coil Winding Method

    Directory of Open Access Journals (Sweden)

    Xingjun Lv

    2011-11-01

    Full Text Available In this paper, a novel kind of method to monitor corrosion expansion of steel rebars in steel reinforced concrete structures named fiber optic coil winding method is proposed, discussed and tested. It is based on the fiber optical Brillouin sensing technique. Firstly, a strain calibration experiment is designed and conducted to obtain the strain coefficient of single mode fiber optics. Results have shown that there is a good linear relationship between Brillouin frequency and applied strain. Then, three kinds of novel fiber optical Brillouin corrosion expansion sensors with different fiber optic coil winding packaging schemes are designed. Sensors were embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion, and their performance was studied in a designed electrochemical corrosion acceleration experiment. Experimental results have shown that expansion strain along the fiber optic coil winding area can be detected and measured by the three kinds of sensors with different measurement range during development the corrosion. With the assumption of uniform corrosion, diameters of corrosion steel rebars were obtained using calculated average strains. A maximum expansion strain of 6,738 με was monitored. Furthermore, the uniform corrosion analysis model was established and the evaluation formula to evaluate mass loss rate of steel rebar under a given corrosion rust expansion rate was derived. The research has shown that three kinds of Brillouin sensors can be used to monitor the steel rebar corrosion expansion of reinforced concrete structures with good sensitivity, accuracy and monitoring range, and can be applied to monitor different levels of corrosion. By means of this kind of monitoring technique, quantitative corrosion expansion monitoring can be carried out, with the virtues of long durability, real-time monitoring and quasi-distribution monitoring.

  4. A special correcting winding for the l = 2 torsatron with split-type helical coils

    International Nuclear Information System (INIS)

    Kotenko, V.G.

    2012-01-01

    A split-type special correcting winding (split-type SCW) for the l = 2 torsatron toroidal magnetic system with split-type helical coils is considered. The split-type SCW gives the possibility of controlling the position of the magnetic surface configuration in the direction perpendicular to the torus equatorial plane. Numerical simulations were carried out to investigate the influence of the split-type SCW magnetic field on centered and distant relative to the torus surface magnetic surface configuration with a plane magnetic axis, being promising for the fusion reactor. The configuration is realized in the l = 2 torsatron with split-type helical coils and with the coils of an additional toroidal magnetic field. The calculations show that the split-type SCW magnetic field influence on the initial magnetic surface configuration leads mainly to the magnetic surface configuration displacement along the straight z axis of torus rotation. The displacement of ∼0.1a, a is the minor radius of the torus, has no critical effect on the magnetic surface parameters. An idea on the split-type SCW magnetic field structure is obtained by numerical simulations of the effect of this field as a minority magnetic field imposed on the magnetic field of a well-known configuration. The split-type SCW magnetic field is directed, predominantly along the major radius of the torus within its volume. The displacement range of the closed magnetic surface configuration depends on the split-type SCW magnetic field value.

  5. The forming of a superconductor cable during the winding of a large toroidal field coil

    International Nuclear Information System (INIS)

    Messemer, G.; Zehlein, H.

    1984-01-01

    The feasible range for the tension force which acts on a superconductor cable during the winding of a large D-shaped toroidal field coil depends strongly on the mechanical properties of the cable, on the geometry of the winding pack and on the arrangement of the equipment. The upper limit is imposed by possible damage within the cable. The lower limit is set by the need to assure enough compaction and to overcome the friction forces between the layers. Within this 'corridor' optimal control of elastic prestresses is desirable: this may be chosen with regard to the residual stresses and/or the elastic springback after removal of the coil former. This paper presents a simplified elastica conductor model built by a finite chain of intervals with constant bending moment and curvature. This paper describes the discrete model as well as the iterative shooting method, which finds the equilibrium shape of the conductor. The distributions of bending moment and shear forces around the D-shaped contour, as well as along the conductor, are given. Desirable improvements are outlined. In particular, the possibility of mitigating the stress concentration effect by supporting rollers suitably placed along the 'free' conductor near the bobbin is discussed. (author)

  6. Study of eddy current power loss from outer-winding coils of a magnetic position sensor

    International Nuclear Information System (INIS)

    Liu, C.-P.; Lin, T.-K.; Chang, Y.-H.; Yu, C.-S.; Wu, K.-T.; Wang, S.-J.; Ying, T.-F.; Huang, D.-R.

    2000-01-01

    The present analysis is concerned with eddy current power loss of a magnetic position sensor, which arises from a non-uniform flux linkage distribution between magnetic material and position sensor. In the paper, a magnetic position sensor system is simplified to be an outer-winding coil along the axial direction of a low carbon steel bar, and developed a numerical model to compute the electrical characteristics by an excited current source. According to the simulated and measured data in this proposed model from 2.52 to 11.37 Oes, eddy current power losses of conducting material have a variation of 6.1% and 9.77%, respectively. Finally, the phases of waveform of the induced output voltage will also be obtained in the conducting material, and have a variation of 3.68% obtained by using the current source in the proposed model

  7. A Full-Size High-Temperature Superconducting Coil Employed in a Wind Turbine Generator Setup

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Mijatovic, Nenad; Kellers, Jürgen

    2017-01-01

    of the full generator. This paper deals with the HTS coil employed in the setup. The coil utilizing YBCO tapes is double-layered with 152 turns per layer and is wound on an FeNi9 iron core. Several sensors are installed to monitor the operating status of the coil, e.g., temperature, field, and voltage...

  8. Effect of thermal contact between winding pack and casing on thermal behavior of SST-1 TF coil

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, A.K. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)]. E-mail: aksahu@ipr.res.in; Sarkar, B. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Gupta, N.C. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Panchal, P. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Bhattacharya, R. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Tank, J. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Gupta, G. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Shah, N. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Shukla, P. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Singh, M. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Phadke, G. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Saxena, Y.C. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2006-11-15

    Active cooling of the casing, which houses the winding pack of the large size superconducting magnet used for magnetic confinement of plasma under a steady state configuration, has been one of the points for debate. Toroidal field (TF) coils of SST-1 consists of six double pancakes of Nb-Ti based cable-in-conduit conductor (CICC), duly impregnated and encased in a tight fit stainless steel casing. In order to validate the cooling configuration of the SST-1 TF magnet system, an experiment has been done on one of the full scale TF coil without having cooling channels for the casing. The experimental results show a distributed temperature profile on the casing ranging from the lowest temperature of 17 K to the highest temperature of 29 K. The data obtained has been analyzed on the basis of thermal contact and thermal resistance. The paper will describe the experimental setup, thermo-hydraulic behavior of the CICC in winding condition and the comparison of experimental results with an empirical analysis.

  9. The radiation dose to the coil windings and the production of nitric acid and ozone from PEP synchrotron radiation

    International Nuclear Information System (INIS)

    Nelson, W.R.; Warren, G.J.; Ford, R.L.

    1975-01-01

    A recent calculation indicates that a significant fraction of the synchrotron radiation energy will scatter from and penetrate through the PEP vacuum chamber and out into the air of the tunnel. This could pose some difficult problems such as the formation of nitric acid and ozone in the air. In addition, rough calculations show that the coil windings themselves might be subject to high radiation doses, leading to premature failure. The purpose of this note is to give the results of a series of calculations that predict both the energy-loss to the air as well as the absorbed dose to the coil windings due to a synchrotron spectrum continuously striking the vacuum chamber wall. The energy-loss in the air, in turn, is used to estimate the production of nitric acid and ozone in the air. The calculations are facilitated by means of Monte Carlo program that has been developed at SLAC and HEPL from a basic code. In recent years this code, called SHOWER, has been extensively revised, and for this particular use, the photon energy cut-off extended down to 1 keV. It is quite obvious that an analytical treatment of this problem can easily be made, since the bulk of the calculation involved Compton scattering in the first few layers of aluminum followed by photon attenuation in the lateral chamber wall. we have chosen to use the Monte Carlo approach instead because it is available and relatively easy to do, and because it demonstrates the utility of the EGS code to the PEP community. 13 refs., 8 figs., 3 tabs

  10. The use of mirror image symmetry in coil winding, applications and advantages in magnetic field generation

    International Nuclear Information System (INIS)

    Grotz, T.

    1992-01-01

    In this paper, an improved method of winding inductors, transformers and motors is discovered. This invention greatly enhances the ability to generate magnetic fields with a given amount of wire. This invention may be as fundamental to the use of magnetic fields as was Nikola Tesla's use of rotating magnetic fields for the generation of alternating current

  11. Tennessee Valley and Eastern Kentucky Wind Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Katie Stokes

    2012-05-03

    In December 2009, the Southern Alliance for Clean Energy (SACE), through a partnership with the Appalachian Regional Commission, EKPC, Kentucky's Department for Energy Development and Independence, SACE, Tennessee's Department of Environment and Conservation, and TVA, and through a contract with the Department of Energy, established the Tennessee Valley and Eastern Kentucky Wind Working Group (TVEKWWG). TVEKWWG consists of a strong network of people and organizations. Working together, they provide information to various organizations and stakeholders regarding the responsible development of wind power in the state. Members include representatives from utility interests, state and federal agencies, economic development organizations, non-government organizations, local decision makers, educational institutions, and wind industry representatives. The working group is facilitated by the Southern Alliance for Clean Energy. TVEKWWG supports the Department of Energy by helping educate and inform key stakeholders about wind energy in the state of Tennessee.

  12. Minimisation of Generation Variability of a Group of Wind Plants

    Directory of Open Access Journals (Sweden)

    Dubravko Sabolić

    2017-09-01

    Full Text Available Minimisation of variability of energy delivered from a group of wind plants into the power system using portfolio theory approach was studied. One of the assumptions of that theory is Gaussian distribution of the sample, which is not satisfied in case of wind generation. Therefore, optimisation of a “portfolio” of plants with different goal functions was studied. It was supposed that a decision on distribution of a fixed amount of generation capacity to be installed among a set of geographical locations with known wind statistics is to be made with minimised variability of generation as a goal. In that way the statistical cancellation of variability would be used in the best possible manner. This article is a brief report on results of such an investigation. An example of nine locations in Croatia was used. These locations’ wind statistics are known from historic generation data.

  13. ARCIMBOLDO on coiled coils.

    Science.gov (United States)

    Caballero, Iracema; Sammito, Massimo; Millán, Claudia; Lebedev, Andrey; Soler, Nicolas; Usón, Isabel

    2018-03-01

    ARCIMBOLDO solves the phase problem by combining the location of small model fragments using Phaser with density modification and autotracing using SHELXE. Mainly helical structures constitute favourable cases, which can be solved using polyalanine helical fragments as search models. Nevertheless, the solution of coiled-coil structures is often complicated by their anisotropic diffraction and apparent translational noncrystallographic symmetry. Long, straight helices have internal translational symmetry and their alignment in preferential directions gives rise to systematic overlap of Patterson vectors. This situation has to be differentiated from the translational symmetry relating different monomers. ARCIMBOLDO_LITE has been run on single workstations on a test pool of 150 coiled-coil structures with 15-635 amino acids per asymmetric unit and with diffraction data resolutions of between 0.9 and 3.0 Å. The results have been used to identify and address specific issues when solving this class of structures using ARCIMBOLDO. Features from Phaser v.2.7 onwards are essential to correct anisotropy and produce translation solutions that will pass the packing filters. As the resolution becomes worse than 2.3 Å, the helix direction may be reversed in the placed fragments. Differentiation between true solutions and pseudo-solutions, in which helix fragments were correctly positioned but in a reverse orientation, was found to be problematic at resolutions worse than 2.3 Å. Therefore, after every new fragment-placement round, complete or sparse combinations of helices in alternative directions are generated and evaluated. The final solution is once again probed by helix reversal, refinement and extension. To conclude, density modification and SHELXE autotracing incorporating helical constraints is also exploited to extend the resolution limit in the case of coiled coils and to enhance the identification of correct solutions. This study resulted in a specialized mode

  14. Nylon screws make inexpensive coil forms

    Science.gov (United States)

    Aucoin, G.; Rosenthal, C.

    1978-01-01

    Standard nylon screws act as coil form copper wire laid down in spiral thread. Completed coil may be bonded to printed-circuit board. However, it is impossible to tune coil by adjusting spacing between windings, technique sometimes used with air-core coils.

  15. MICE - Absorber and focus coil safety working group design document: Preliminary design and assessments

    International Nuclear Information System (INIS)

    Barr, Giles; Baynham, Elwyn; Black, Edgar; Bradshaw, Tom; Cummings, Mary Anne; Green, Michael A.; Ishimoto, Shigeru; Ivanyushenkov, Yury; Lau, Wing; Zisman, Michael

    2003-01-01

    A Neutrino Factory based on a muon storage ring is the ultimate tool for studies of neutrino oscillations, including possibly the discovery of leptonic CP violation. it is also the first step toward a muon collider. To develop a stored-muon-beam facility to serve as a Neutrino Factory, it is necessary to ''cool'' a muon beam (decrease its phase-space volume). The short lifetime of the muon, 2.2 (micro)s at rest, eliminates all currently demonstrated cooling techniques and requires that a new, heretofore untried, technique--ionization cooling--be employed. Although ionization cooling of muons has never been demonstrated in practice, it has been shown by end-to-end simulation and design studies to be an important factor both for the performance and for the cost of a Neutrino Factory. This motivates an international program of R and D, including an experimental demonstration at Rutherford Appleton Laboratory (RAL). The aims of the international Muon Ionization Cooling Experiment are: (1) to show that it is possible to design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; and (2) to place it in a muon beam and measure its performance in various modes of operation and beam conditions, thereby investigating the limits and practicality of cooling. The MICE collaboration has designed an experiment in which a section of an ionization cooling channel is exposed to a muon beam. This cooling channel assembles liquid-hydrogen absorbers providing energy loss and high-gradient radio frequency (RF) cavities to re-accelerate the particles, all tightly contained in a magnetic channel. It reduces the beam transverse emittance by > 10% for muon momenta between 140 and 240 MeV/c. The layout of the experiment is shown. They utilize one complete magnetic cell of the cooling channel, comprising three absorber-focus-coil (AFC) modules and two RF-coupling-coil (RFCC) modules. Spectrometers placed before and after the

  16. Split Coil Forms for Rotary Transformers

    Science.gov (United States)

    Mclyman, C. W. T.

    1982-01-01

    Split cores for rotor and stator windings of rotary transformer mounted around their respective coils (which are in bobbins) and cemented together. This arrangement simplifies winding of stator coil to go in a slot in inner diameter of stator coil. One practical application of rotary transformers fabricated according to this technique is for centrifuges, in which conventional sliprings are of uncertain reliability.

  17. Wind turbine/generator set having a stator cooling system located between stator frame and active coils

    Science.gov (United States)

    Bevington, Christopher M.; Bywaters, Garrett L.; Coleman, Clint C.; Costin, Daniel P.; Danforth, William L.; Lynch, Jonathan A.; Rolland, Robert H.

    2012-11-13

    A wind turbine comprising an electrical generator that includes a rotor assembly. A wind rotor that includes a wind rotor hub is directly coupled to the rotor assembly via a simplified connection. The wind rotor and generator rotor assembly are rotatably mounted on a central spindle via a bearing assembly. The wind rotor hub includes an opening having a diameter larger than the outside diameter of the central spindle adjacent the bearing assembly so as to allow access to the bearing assembly from a cavity inside the wind rotor hub. The spindle is attached to a turret supported by a tower. Each of the spindle, turret and tower has an interior cavity that permits personnel to traverse therethrough to the cavity of the wind rotor hub. The wind turbine further includes a frictional braking system for slowing, stopping or keeping stopped the rotation of the wind rotor and rotor assembly.

  18. Compact stellarator coils

    International Nuclear Information System (INIS)

    Pomphrey, N.; Berry, L.A.; Boozer, A.H.

    2001-01-01

    Experimental devices to study the physics of high-beta (β>∼4%), low aspect ratio (A<∼4.5) stellarator plasmas require coils that will produce plasmas satisfying a set of physics goals, provide experimental flexibility, and be practical to construct. In the course of designing a flexible coil set for the National Compact Stellarator Experiment, we have made several innovations that may be useful in future stellarator design efforts. These include: the use of Singular Value Decomposition methods for obtaining families of smooth current potentials on distant coil winding surfaces from which low current density solutions may be identified; the use of a Control Matrix Method for identifying which few of the many detailed elements of the stellarator boundary must be targeted if a coil set is to provide fields to control the essential physics of the plasma; the use of Genetic Algorithms for choosing an optimal set of discrete coils from a continuum of potential contours; the evaluation of alternate coil topologies for balancing the tradeoff between physics objective and engineering constraints; the development of a new coil optimization code for designing modular coils, and the identification of a 'natural' basis for describing current sheet distributions. (author)

  19. Coil Optimization for HTS Machines

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech

    An optimization approach of HTS coils in HTS synchronous machines (SM) is presented. The optimization is aimed at high power SM suitable for direct driven wind turbines applications. The optimization process was applied to a general radial flux machine with a peak air gap flux density of ~3T...... is suitable for which coil segment is presented. Thus, the performed study gives valuable input for the coil design of HTS machines ensuring optimal usage of HTS tapes....

  20. Large superconducting coil fabrication development

    International Nuclear Information System (INIS)

    Brown, R.L.; Allred, E.L.; Anderson, W.C.; Burn, P.B.; Deaderick, R.I.; Henderson, G.M.; Marguerat, E.F.

    1975-01-01

    Toroidal fields for some fusion devices will be produced by an array of large superconducting coils. Their size, space limitation, and field requirements dictate that they be high performance coils. Once installed, accessibility for maintenance and repairs is severely restricted; therefore, good reliability is an obvious necessity. Sufficient coil fabrication will be undertaken to develop and test methods that are reliable, fast, and economical. Industrial participation will be encouraged from the outset to insure smooth transition from development phases to production phases. Initially, practice equipment for three meter bore circular coils will be developed. Oval shape coil forms will be included in the practice facility later. Equipment that is more automated will be developed with the expectation of winding faster and obtaining good coil quality. Alternate types of coil construction, methods of winding and insulating, will be investigated. Handling and assembly problems will be studied. All technology developed must be feasible for scaling up when much larger coils are needed. Experimental power reactors may need coils having six meter or larger bores

  1. Low-Cost Superconducting Wire for Wind Generators: High Performance, Low Cost Superconducting Wires and Coils for High Power Wind Generators

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    REACT Project: The University of Houston will develop a low-cost, high-current superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. The University of Houston’s innovation is based on engineering nanoscale defects in the superconducting film. This could quadruple the current relative to today’s superconducting wires, supporting the same amount of current using 25% of the material. This would make wind generators lighter, more powerful and more efficient. The design could result in a several-fold reduction in wire costs and enable their commercial viability of high-power wind generators for use in offshore applications.

  2. Rope coiling

    Indian Academy of Sciences (India)

    Sitichoke Amnuanpol

    2017-10-19

    Oct 19, 2017 ... In rope coiling the centre of the circle is static. How- ever, it evolves in time as seen in the curling of .... friction force between the rope and the plane, because no significant changes in the coiling radius R and ... friction force relative to the axial compressive forces,. i.e. gravitational force and inertial force, ...

  3. Rope coiling

    Indian Academy of Sciences (India)

    We present the results of the combined experimental and theoretical investigation of rope coiling arising from the buckling instability. The shape of the rope is perfectly circular in the coiling region and is straight in the region below the feeding point. In between these two distant regions, the rope assumes a catenary-like ...

  4. Fabrication of 'TAMU3', a 'Wind/React' stress-managed 14T Nb3Sn block coil design

    International Nuclear Information System (INIS)

    Blackburn, R; Diaczenko, N; Elliott, T; Jaisle, A; McInturff, A; McIntyre, P; Sattarov, A

    2008-01-01

    The third phase of a high field dipole technology development, a full set (2+) of Stress-Managed winding modules is being fabricated. The dipole fabrication uses tooling, fixtures, procedures and technology modified and updated based on the second phase work and results reported plus new material developments and higher performance strand. The strand was furnished by the DOE HEP Nb 3 Sn conductor development program. The modules' cables were processed and cabled by the LBNL facility using the latest procedures developed. There were several new materials and processes introduced in this third phase to improve performance or simplify the fabrication which will be discussed. If all the performance inherent in the strand were to be achieved then the peak field should be higher than 14 T. The containment and flux return structure are the same as used in phase 2. This phase of the development will constitute the outer winding modules of a 'Collider' prototype Block dipole with Stress-Management. The lessons learned and the results obtained will be discussed

  5. Novel Use of Water Soluble "Aquapour" As A Temporary Spacer During Coil Winding For The NSTX-U Centerstack

    Energy Technology Data Exchange (ETDEWEB)

    Mardenfeld, Michael

    2013-07-01

    A major facility upgrade to the National Spherical Torus eXperiment (NSTX-U) is currently underway at Princeton Plasma Physics Laboratory (PPPL). A key component of NSTX-U is the fabrication of a new, higher field centerstack (CS). In order to simultaneously provide robust joints between the inner and outer legs of the Toroidal Field Coils (TF) and minimize radial build, the NSTX-U CS design requires that the Ohmic Heating solenoid (OH) be wound directly on the inner TF bundle. To protect the OH against thermal expansion stress during scenarios where the inner TF bundle is hot but the OH is relatively cool, the completed CS will have a 0.100 inch annular gap between the outer diameter of the TF bundle and the inner diameter of the OH solenoid. "Aquapour", a proprietary material produced by the Advanced Ceramics Manufacturing Company will be used during manufacture to produce this gap. After the TF bundle is vacuum pressure impregnated and cured, a cylindrical "clam shell" mold will be assembled around it, and a slurry of powdered Aquapour and water will be pumped into the annular space between the mold and TF bundle. Subsequent baking will turn the Aquapour solid, and a protective layer of wet lay-up fiberglass and resin will be added. The OH solenoid will be wound directly on this wet lay-up shell. After vacuum pressure impregnation of the OH, the water soluble Aquapour will be washed away, leaving the required radial clearance between the TF and OH. This paper will describe prototyping and testing of this process, and plans for use on the actual CS fabrication.

  6. Optimal Control of a Wind Farm Group Using the WindEx System

    Directory of Open Access Journals (Sweden)

    Piotr Kacejko

    2014-09-01

    Full Text Available The aim of this paper is to present achievements obtained in implementing the framework project N R01 0021 06 in the Power System Department of Lublin University of Technology. The result of the work was “A system of optimal wind farm power control in the conditions of limited transmission capabilities of power networks”, which one of two main modules is a state estimator. The featured wind farm control system was integrated with a SCADA dispatcher system WindEx using the WebSVC service.

  7. Optimal Control of a Wind Farm Group Using the WindEx System

    OpenAIRE

    Piotr Kacejko; Michał Wydra; Robert Jędrychowski

    2014-01-01

    The aim of this paper is to present achievements obtained in implementing the framework project N R01 0021 06 in the Power System Department of Lublin University of Technology. The result of the work was “A system of optimal wind farm power control in the conditions of limited transmission capabilities of power networks”, which one of two main modules is a state estimator. The featured wind farm control system was integrated with a SCADA dispatcher system WindEx using the WebSVC service.

  8. α/β coiled coils

    Science.gov (United States)

    Hartmann, Marcus D; Mendler, Claudia T; Bassler, Jens; Karamichali, Ioanna; Ridderbusch, Oswin; Lupas, Andrei N; Hernandez Alvarez, Birte

    2016-01-01

    Coiled coils are the best-understood protein fold, as their backbone structure can uniquely be described by parametric equations. This level of understanding has allowed their manipulation in unprecedented detail. They do not seem a likely source of surprises, yet we describe here the unexpected formation of a new type of fiber by the simple insertion of two or six residues into the underlying heptad repeat of a parallel, trimeric coiled coil. These insertions strain the supercoil to the breaking point, causing the local formation of short β-strands, which move the path of the chain by 120° around the trimer axis. The result is an α/β coiled coil, which retains only one backbone hydrogen bond per repeat unit from the parent coiled coil. Our results show that a substantially novel backbone structure is possible within the allowed regions of the Ramachandran space with only minor mutations to a known fold. DOI: http://dx.doi.org/10.7554/eLife.11861.001 PMID:26771248

  9. Composite coils for toroidal field coils and method of using same

    International Nuclear Information System (INIS)

    Perkins, R. G.; Trujillo, S. M.

    1985-01-01

    A composite toroidal field (TF) generating means consisting of segmented magnetic coil windings is disclosed. Each coil winding of the TF generating means consists of a copper or copper alloy conductor segment and an aluminum or aluminum alloy conductor segment. The conductor segments are joined at a high strength, low electrical resistance joint and the joint may either be a mechanical or metallurgical one. The use of the aluminum or aluminum alloy conductor segments improves the neutron economy of the reactor with which the TF coil is associated and reduces TF coil nuclear heating and heating gradients, and activation in the TF coils

  10. Structural specificity in coiled-coil interactions

    OpenAIRE

    Grigoryan, Gevorg; Keating, Amy E.

    2008-01-01

    Coiled coils have a rich history in the field of protein design and engineering. Novel structures, such as the first 7-helix coiled coil, continue to provide surprises and insights. Large-scale data sets quantifying the influence of systematic mutations on coiled-coil stability are a valuable new asset to the area. Scoring methods based on sequence and/or structure can predict interaction preferences in coiled-coil-mediated bZIP transcription factor dimerization. Experimental and computationa...

  11. Pulse coil concepts for the LCP Facility

    International Nuclear Information System (INIS)

    Nelson, B.E.; Burn, P.B.

    1977-01-01

    The pulse coils described in this paper are resistive copper magnets driven by time-varying currents. They are included in the Large Coil Test Facility (LCTF) portion of the Large Coil Program (LCP) to simulate the pulsed field environment of the toroidal coils in a tokamak reactor. Since TNS (a 150 sec, 5MA, igniting tokamak) and the Oak Ridge EPR (Experimental Power Reactor) are representative of the first tokamaks to require the technology developed in LCP, the reference designs for these machines, especially TNS, are used to derive the magnetic criteria for the pulse coils. This criteria includes the magnitude, distribution, and rate of change of pulsed fields in the toroidal coil windings. Three pulse coil concepts are evaluated on the basis of magnetic criteria and factors such as versatility of design, ease of fabrication and cost of operation. The three concepts include (1) a pair of poloidal coils outside the LCTF torus, (2) a single poloidal coil threaded through the torus, and (3) a pair of vertical axis coil windings inside the bore of one or more of the toroidal test coils

  12. Ejector COIL

    Science.gov (United States)

    Nikolaev, Valeriy D.; Svistun, Michael I.; Zagidullin, Marsel V.

    2004-06-01

    The historical ejector-like chemical oxygen iodine laser (COIL) contribution at the Lebedev Physical Institute, Samara Branch is briefly presented. Two possible schemes of such COIL which provide the high exhaust pressure are considered. The high-pressure hot driver nitrogen is carrier of iodine vapor in the first scheme. In the second version the additional nozzles with the low-pressure secondary nitrogen are employed for injection iodine vapor but the pure high-pressure driver nitrogen has the room temperature. The last COIL version was investigated in Lebedev Physical Institute in more detail and results of these investigations are presented. This ejector nozzle bank generates gain medium with high Mach number, low temperature and high gain. A high chemical efficiency up to 25% and the potential pressure recovery up to 90 torr have been achieved simultaneously.

  13. R&D for a single-layer $Nb_{3}Sn$ common coil dipole using the react-and-wind fabrication technique

    CERN Document Server

    Ambrosio, G; Barzi, E; Bauer, P; Chichili, D R; Ewald, K D; Fehér, S; Imbasciati, L; Kashikhin, V V; Limon, P J; Litvinenko, L; Novitski, I; Rey, J M; Scanlan, R M; Yadav, S; Yamada, R; Zlobin, A V

    2002-01-01

    A dipole magnet based on the common coil design, using prereacted Nb /sub 3/Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting in a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrica...

  14. Scaffolds, levers, rods and springs: diverse cellular functions of long coiled-coil proteins.

    Science.gov (United States)

    Rose, A; Meier, I

    2004-08-01

    Long alpha-helical coiled-coil proteins are involved in a variety of organizational and regulatory processes in eukaryotic cells. They provide cables and networks in the cyto- and nucleoskeleton, molecular scaffolds that organize membrane systems, motors, levers, rotating arms and possibly springs. A growing number of human diseases are found to be caused by mutations in long coiled-coil proteins. This review summarizes our current understanding of the multifaceted group of long coiled-coil proteins in the cytoskeleton, nucleus, Golgi and cell division apparatus. The biophysical features of coiled-coil domains provide first clues toward their contribution to the diverse protein functions and promise potential future applications in the area of nanotechnology. Combining the power of fully sequenced genomes and structure prediction algorithms, it is now possible to comprehensively summarize and compare the complete inventory of coiled-coil proteins of different organisms.

  15. A precise technique for manufacturing correction coil

    International Nuclear Information System (INIS)

    Schieber, L.

    1992-01-01

    An automated method of manufacturing correction coils has been developed which provides a precise embodiment of the coil design. Numerically controlled machines have been developed to accurately position coil windings on the beam tube. Two types of machines have been built. One machine bonds the wire to a substrate which is wrapped around the beam tube after it is completed while the second machine bonds the wire directly to the beam tube. Both machines use the Multiwire reg-sign technique of bonding the wire to the substrate utilizing an ultrasonic stylus. These machines are being used to manufacture coils for both the SSC and RHIC

  16. Power loss problems in EXTRAP coil systems

    International Nuclear Information System (INIS)

    Lehnert, B.

    1977-02-01

    The Ohmic power loss in the coils of external ring traps is minimized with respect to the thermonuclear power production. In the case of the DT-reaction this leads to dimensions and power densities being relevant to full-scale reactors. Not only superconducting or refrigerated coil windings can thus be used, but also hot-coil systems which are operated at several hundred degrees centrigrade and form part of a steam cycle and power extraction system. For hot coils the problems of void formation and tritium regeneration have to be further examined. The high beta value leads to moderately large coil stresses. Finally, replacement and repair become simplified by the present coil geometry. (Auth.)

  17. R and D for a single-layer Nb3Sn common coil dipole using the react-and-wind fabrication technique

    International Nuclear Information System (INIS)

    Ambrosio, Giorgio

    2002-01-01

    A dipole magnet based on the common coil design, using prereacted Nb 3 Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R and D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting of a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of the program, and reports the results of fabrication and test of cable, collars and the mechanical model

  18. Coiled-Coil Design: Updated and Upgraded.

    Science.gov (United States)

    Woolfson, Derek N

    2017-01-01

    α-Helical coiled coils are ubiquitous protein-folding and protein-interaction domains in which two or more α-helical chains come together to form bundles. Through a combination of bioinformatics analysis of many thousands of natural coiled-coil sequences and structures, plus empirical protein engineering and design studies, there is now a deep understanding of the sequence-to-structure relationships for this class of protein architecture. This has led to considerable success in rational design and what might be termed in biro de novo design of simple coiled coils, which include homo- and hetero-meric parallel dimers, trimers and tetramers. In turn, these provide a toolkit for directing the assembly of both natural proteins and more complex designs in protein engineering, materials science and synthetic biology. Moving on, the increased and improved use of computational design is allowing access to coiled-coil structures that are rare or even not observed in nature, for example α-helical barrels, which comprise five or more α-helices and have central channels into which different functions may be ported. This chapter reviews all of these advances, outlining improvements in our knowledge of the fundamentals of coiled-coil folding and assembly, and highlighting new coiled coil-based materials and applications that this new understanding is opening up. Despite considerable progress, however, challenges remain in coiled-coil design, and the next decade promises to be as productive and exciting as the last.

  19. Vehicle to wireless power transfer coupling coil alignment sensor

    Science.gov (United States)

    Miller, John M.; Chambon, Paul H.; Jones, Perry T.; White, Clifford P.

    2016-02-16

    A non-contacting position sensing apparatus includes at least one vehicle-mounted receiver coil that is configured to detect a net flux null when the vehicle is optimally aligned relative to the primary coil in the charging device. Each of the at least one vehicle-mounted receiver coil includes a clockwise winding loop and a counterclockwise winding loop that are substantially symmetrically configured and serially connected to each other. When the non-contacting position sensing apparatus is located directly above the primary coil of the charging device, the electromotive forces from the clockwise winding loop and the counterclockwise region cancel out to provide a zero electromotive force, i.e., a zero voltage reading across the coil that includes the clockwise winding loop and the counterclockwise winding loop.

  20. Crystallographic study on oligonucleotide coiled-coils

    OpenAIRE

    Luchi, Daniela de

    2008-01-01

    En la presente tesis doctoral se han realizado estudios estructurales de DNA. Estudios previos han demostrado que los coiled-coils de d(ATATATATATAT) y d(ATATATATAT) tienen unos parámetros geométricos muy diferentes. El objetivo de esta tesis es aclarar las propiedades de los coiled-coils.Con esta finalidad se han estudiado por cristalografía de Rayos X oligonucleótidos con diferentes secuencias y con extremos cohesivos que fijen la geometría de los coiled-coils. Se han utilizado oligonucleót...

  1. New technique for wiring SSC superconducting sextupole corrector coils

    International Nuclear Information System (INIS)

    Leon, B.

    1985-01-01

    There exists in the electronics industry, a technology for the manufacture of printed circuit (PC) boards which is directly transferable into the creation of highly controlled coils, such as the SSC sextupole superconducting corrector coils. This technology, which uses a process of laying down insulated wire in highly controlled patterns has heretofore been confined exclusively to the manufacture of high density printed circuit (PC) boards, possibly due to an ignorance of its utility in the field of precision winding of coils. This ability to fix wires in a well defined location can be used to produce precision wound coils in a very cost-effective manner. These coils may be superior in quality to conventionally made coils. Before describing what can be created with this technology, it is necessary to take a look at this coil winding process, the MULTIWIRE process, and the industry which has utilized this technology

  2. A new technique for wiring SSC superconducting sextupole corrector coils

    International Nuclear Information System (INIS)

    Leon, B.

    1985-01-01

    There exists in the electronics industry, a technology for the manufacture of printed circuit (PC) boards which is directly transferable into the creation of highly controlled coils, such as the SSC sextupole superconducting corrector coils. This technology, which uses a process of laying down insulated wire in highly controlled patterns, has heretofore been confined excusively to the manufacture of high density printed circuit (PC) boards, possibly due to an ignorance of its utility in the field of precision winding of coils. This ability to fix wires in a well defined location can be used to produce precision wound coils in a very cost-effective manner. These coils may be superior in quality to conventionally made coils. Before describing what can be created with this technology, it is necessary to take a look at this coil winding process, the MULTIWIRE process, and the industry which has utilized this technology

  3. Design considerations for ITER toroidal field coils

    International Nuclear Information System (INIS)

    Kalsi, S.S.; Lousteau, D.C.; Miller, J.R.

    1987-01-01

    The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Europe, Japan, the Union of Soviet Socialist Republics (U.S.S.R.), and the United States. This paper describes a magnetic and mechanical design methodology for toroidal field (TF) coils that employs Nb 3 Sn superconductor technology. Coil winding is sized by using conductor concepts developed for the U.S. TIBER concept. Manifold concepts are presented for the complete cooling system. Also included are concepts for the coil structural arrangement. The effects of in-plane and out-of-plane loads are included in the design considerations for the windings and case. Concepts are presented for reacting these loads with a minimum amount of additional structural material. Concepts discussed in this paper could be considered for the ITER TF coils

  4. Predicting coiled coils by use of pairwise residue correlations.

    OpenAIRE

    Berger, B; Wilson, D B; Wolf, E; Tonchev, T; Milla, M; Kim, P S

    1995-01-01

    A method is presented that predicts coiled-coil domains in protein sequences by using pairwise residue correlations obtained from a (two-stranded) coiled-coil database of 58,217 amino acid residues. A program called PAIRCOIL implements this method and is significantly better than existing methods at distinguishing coiled coils from alpha-helices that are not coiled coils. The database of pairwise residue correlations suggests structural features that stabilize or destabilize coiled coils.

  5. 30 MJ superconducting coil design and fabrication. Report No. GA-A16104

    International Nuclear Information System (INIS)

    Purcell, J.R.

    1980-09-01

    The Bonneville 30 MJ superconducting stabilizing coil is being constructed by General Atomic under contract to LASL. Upon completion of the design, General Atomic began the procurement of materials and is now ready to start coil winding

  6. Evolutionary patterns in coiled-coils.

    Science.gov (United States)

    Surkont, Jaroslaw; Pereira-Leal, Jose B

    2015-01-10

    Models of protein evolution are used to describe evolutionary processes, for phylogenetic analyses and homology detection. Widely used general models of protein evolution are biased toward globular domains and lack resolution to describe evolutionary processes for other protein types. As three-dimensional structure is a major constraint to protein evolution, specific models have been proposed for other types of proteins. Here, we consider evolutionary patterns in coiled-coil forming proteins. Coiled-coils are widespread structural domains, formed by a repeated motif of seven amino acids (heptad repeat). Coiled-coil forming proteins are frequently rods and spacers, structuring both the intracellular and the extracellular spaces that often form protein interaction interfaces. We tested the hypothesis that due to their specific structure the associated evolutionary constraints differ from those of globular proteins. We showed that substitution patterns in coiled-coil regions are different than those observed in globular regions, beyond the simple heptad repeat. Based on these substitution patterns we developed a coiled-coil specific (CC) model that in the context of phylogenetic reconstruction outperforms general models in tree likelihood, often leading to different topologies. For multidomain proteins containing both a coiled-coil region and a globular domain, we showed that a combination of the CC model and a general one gives higher likelihoods than a single model. Finally, we showed that the model can be used for homology detection to increase search sensitivity for coiled-coil proteins. The CC model, software, and other supplementary materials are available at http://www.evocell.org/cgl/resources (last accessed January 29, 2015). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  7. A group-based spatial decision support system for wind farm site selection in Northwest Ohio

    International Nuclear Information System (INIS)

    Gorsevski, Pece V.; Cathcart, Steven C.; Mirzaei, Golrokh; Jamali, Mohsin M.; Ye, Xinyue; Gomezdelcampo, Enrique

    2013-01-01

    The purpose of this paper is to demonstrate the benefits of applying a spatial decision support system (SDSS) framework for evaluating the suitability for wind farm siting in Northwest Ohio. The multiple criteria evaluation (MCE) prototype system is intended for regional planning but also for promoting group decision making that could involve participants with different interests in the development of decision alternatives. The framework integrates environmental and economic criteria and builds a hierarchy for wind farm siting using weighted linear combination (WLC) techniques and GIS functionality. The SDSS allows the multiple participants to interact and develop an understanding of the spatial data for assigning importance values to each factor. The WLC technique is used to combine the assigned values with map layers, which are standardized using fuzzy set theory, to produce individual suitability maps. The maps created by personal preferences from the participants are aggregated for producing a group solution using the Borda method. Sensitivity analysis is performed on the group solution to examine how small changes in the factor weights affect the calculated suitability scores. The results from the sensitivity analysis are intended to aid understanding of compromised solutions through changes in the input data from the participant's perspective. - Highlights: ► We present a prototype tool that we developed for wind farm site selection. ► Multiple participants rank the factors for promoting group-based decision making. ► The factors are aggregated by WLC technique to generate maps from participants. ► Group-based solution uses Borda method to aggregate the maps from participants. ► Sensitivity analysis is performed on the group solution to examine solution affects

  8. Progress on large superconducting toroidal field coils

    International Nuclear Information System (INIS)

    Haubenreich, P.N.; Luton, J.N.; Thompson, P.B.; Beard, D.S.

    1979-01-01

    Large superconducting toroidal field coils of competing designs are being produced by six major industrial teams. In the US, teams headed by General Dynamics Convair, General Electric, and Westinghouse are under contract to design and fabricate one coil each to specifications established by the Large Coil Program. A facility for testing 6 coils in a toroidal array at fields to 8 to 12 tesla is under construction at Oak Ridge. Through an international agreement, EURATOM, Japan, and Switzerland will produce one coil each for testing with the US coils. Each test coil will have a 2.5 x 3.5 m D-shape winding bore and is designed to operate at a current of 10 to 18 kA at a peak field of 8T while subjected to pulsed fields of 0.14 T applied in 1.0 s. There are significant differences among the six coil designs: five use NbTi, one Nb 3 Sn; three are cooled by pool boiling helium, three by forced flow; five have welded or bolted stainless steel coil cases, one has aluminum plate structure. All are designed to be cryostable at 8T, with structural margin for extended operation. The three US coil teams are almost or completely finished with detailed design and are now procuring materials and setting up manufacturing equipment. The non-US teams are at various stages of verification testing and design. The GDC and GE coils are scheduled for delivery in the spring of 1981 and the others will be completed a year later. The 11-m diameter vessel at the test facility has been completed and major components of the test stand are being procured. Engineering and procurement to upgrade the helium liquifier-refrigerator system are under way

  9. Programming protein self assembly with coiled coils

    Science.gov (United States)

    Dietz, Hendrik; Bornschlögl, Thomas; Heym, Roland; König, Frauke; Rief, Matthias

    2007-11-01

    The controlled assembly of protein domains into supramolecular structures will be an important prerequisite for the use of functional proteins in future nanotechnology applications. Coiled coils are multimerization motifs whose dimerization properties can be programmed by amino acid sequence. Here, we report programmed supramolecular self-assembly of protein molecules using coiled coils and directly demonstrate its potential on the single molecule level by AFM force spectroscopy. We flanked two different model proteins, Ig27 from human cardiac titin and green fluorescent protein (GFP), by coiled coil binding partners and studied the capability of these elementary building blocks to self-assemble into linear chains. Simple sterical constraints are shown to control the assembly process, providing evidence that many proteins can be assembled with this method. An application for this technique is the design of polyproteins for single molecule force spectroscopy with an integrated force-calibration standard.

  10. HydroCoil as an adjuvant to bare platinum coil treatment of 100 cerebral aneurysms

    International Nuclear Information System (INIS)

    Fanning, Noel F.; Berentei, Zsolt; Brennan, Paul R.; Thornton, John

    2007-01-01

    Introduction The overall safety of the HydroCoil, an expansile hybrid hydrogel-platinum coil, is unknown. We report a prospective observational study of our first 100 cerebral aneurysms treated with HydroCoils, focusing on safety and initial efficacy.Methods Indications, procedural complications, clinical and angiographic outcomes were recorded. Packing density, number of coils deployed and angiographic results were compared with those in a matched control group of 100 aneurysms treated solely with bare platinum coils. HydroCoil complication rates were compared to bare platinum coil rates at our institution and in published series. Results Adjuvant HydroCoil treatment led to increased mean percentage aneurysm filling compared to controls (50 ± 21% versus 27 ± 13%, P < 0.001). Immediate posttreatment angiographic results showed significantly (P < 0.001) more complete occlusions and fewer incomplete (<95%) occlusions compared to controls. Intermediate follow-up angiograms (median 7.5 months) in 63 aneurysms showed a trend towards fewer incomplete occlusions with HydroCoil treatment. There were significantly fewer major recurrences with HydroCoil treatment compared to the control treatment (9.5% versus 22.6%, P 0.046). In the adjuvant HydroCoil group, major recurrent aneurysms had significantly less percentage volume packing with HydroCoils than non-recurrent aneurysms (50.3 ± 5.0% versus 65.3 ± 18.0%, P = 0.04). There was a 12% procedural complication rate, 6% procedural morbidity and 1% mortality rate, similar to institutional and reported bare platinum coil complication rates.Conclusion HydroCoils can be safely deployed with a similar complication rate to bare platinum coils. They result in improved aneurysm filling. Intermediate follow-up angiography showed significantly fewer major recurrences. Long-term follow-up is required to confirm initial improved stability. (orig.)

  11. Design of superconducting toroidal magnet coils and testing facility in the USA

    International Nuclear Information System (INIS)

    Luton, J.N.; Haubenreich, P.N.; Thompson, P.B.

    1977-01-01

    In the U.S. Large Coil Program, three industrial teams are presently designing test coils to general specifications prepared by the Oak Ridge National Laboratory with guidance from USERDA. Each test coil is approximately half the bore size of reactor coils, being oval or D-shaped, with a bore of 2.5 x 3.5 m. The dimensions and operating requirements of the coils are identical for all test coils. The coils are designed to produce a peak field of at least 8 tesla at the winding of a selected coil operated at its design current. This condition is met when the selected coil is operated in a compact toroidal array of 6 coils, with the other five coils being operated at 0.8 of their design current. The six coils are of three different designs. Both pool boiling and forced flow designs are included. The coils are housed in a single large vacuum chamber for economy and testing convenience. Auxiliary coils provide a pulse field over the test coil winding volume. This auxiliary system is designed to produce a pulse field which rises to a peak of 0.14 T in 1 sec. With the exception of material damage due to neutron irradiation, all reactor requirements and environments will be either duplicated, approximated, or simulated. The test facility is being designed to accept coils producing up to 12 tesla in later phases of the program

  12. Computational characterization of parallel dimeric and trimeric coiled-coils using effective amino acid indices.

    Science.gov (United States)

    Li, Chen; Wang, Xiao-Feng; Chen, Zhen; Zhang, Ziding; Song, Jiangning

    2015-02-01

    The coiled-coil, which consists of two or more α-helices winding around each other, is a ubiquitous and the most frequently observed protein-protein interaction motif in nature. The coiled-coil is known for its straightforward heptad repeat pattern and can be readily recognized based on protein primary sequences, exhibiting a variety of oligomer states and topologies. Due to the stable interaction formed between their α-helices, coiled-coils have been under close scrutiny to design novel protein structures for potential applications in the fields of material science, synthetic biology and medicine. However, their broader application requires an in-depth and systematic analysis of the sequence-to-structure relationship of coiled-coil folding and oligomeric formation. In this article, we propose a new oligomerization state predictor, termed as RFCoil, which exploits the most useful and non-redundant amino acid indices combined with the machine learning algorithm - random forest (RF) - to predict the oligomeric states of coiled-coil regions. Benchmarking experiments show that RFCoil achieves an AUC (area under the ROC curve) of 0.849 on the 10-fold cross-validation test using the training dataset and 0.855 on the independent test using the validation dataset, respectively. Performance comparison results indicate that RFCoil outperforms the four existing predictors LOGICOIL, PrOCoil, SCORER 2.0 and Multicoil2. Furthermore, we extract a number of predominant rules from the trained RF model that underlie the oligomeric formation. We also present two case studies to illustrate the applicability of the extracted rules to the prediction of coiled-coil oligomerization state. The RFCoil web server, source codes and datasets are freely available for academic users at http://protein.cau.edu.cn/RFCoil/.

  13. 12 tesla test coil. Annual progress report

    International Nuclear Information System (INIS)

    1979-01-01

    The Plasma Fusion Center at MIT has been charged with responsibility for the design, development, fabrication and test operation of a Niobium-3-Tin Superconducting Test Coil. Research is described on DOE's 12 tesla coil demonstration program in which several one-meter diameter superconducting test coils will be inserted and tested in DOE's High Field Test Facility at the Lawrence Livermore Laboratories. The work was initiated at the start of FY 79. FY 79 saw the completion of our Preliminary Design and the initiation of three (3) subcontracts: (1) Westinghouse review of the Preliminary Design, (II) Supercon, Inc. development of a tubular copper matrix, Nb 3 Sn Superconductor and (III) Airco optimization of the LCP-W Nb 3 Sn superconductor for 12T service. In addition, Airco was charged with the production of a 1000 foot length of model 15,000A conductor. Coil winding exercises were initiated at the Everson Electric Company

  14. Measurement of a Conduction Cooled Nb3Sn Racetrack Coil

    Science.gov (United States)

    Kim, HS; Kovacs, C.; Rochester, J.; Sumption, MD; Tomsic, M.; Peng, X.; Doll, D.

    2017-12-01

    Use of superconducting coils for wind turbines and electric aircraft is of interest because of the potential for high power density and weight reduction. Here we test a racetrack coil developed as a proof-of-concept for cryogen-free superconducting motors and generators. The coil was wound with 1209 m of 0.7-mm-diameter insulated tube-type Nb3Sn wire. The coil was epoxy-impregnated, instrumented, covered with numerous layers of aluminized mylar insulation, and inserted vertically into a dewar. The system was cooled to 4.2 K, and a few inches of liquid helium was allowed to collect at the bottom of the dewar but below the coil. The coil was cooled by conduction via copper cooling bars were attached to the coil but also were immersed in the liquid helium at their lower ends. Several current tests were performed on the coil, initially in voltage mode, and one run in current mode. The maximum coil Ic at 4.2 K was 480 A, generating 3.06 T at the surface of the coil. The coil met the design targets with a noticeable margin.

  15. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group, Spring 2007

    Energy Technology Data Exchange (ETDEWEB)

    None

    2007-03-01

    DOE's Wind Powering America program has initiated a quarterly NAWIG newsletter to present Native American wind information, including projects, interviews with pioneers, issues, WPA activities, and related events.

  16. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group, Summer 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-06-01

    DOE's Wind Powering America program has initiated a quarterly NAWIG newsletter to present Native American wind information, including projects, interviews with pioneers, issues, WPA activities, and related events.

  17. Relationship between voice coil fill factor and loudspeaker efficiency

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    -mode technology, can be designed to much lower loads. A thorough analysis of the loudspeaker efficiency is presented and its relation to the voice coil fill factor is described. In addition to this the influence of the driver’s mass ratio is investigated and it is found that high mass ratios is beneficial...... for the efficiency of drivers using high fill factor voice coils. Different voice coil winding strategies are described and their fill factors analysed. It is found that by lowering the nominal resistance of a voice coil, using rectangular wire, one can increase the fill factor. However a practical realization...

  18. Biomaterials Made from Coiled-Coil Peptides.

    Science.gov (United States)

    Conticello, Vincent; Hughes, Spencer; Modlin, Charles

    The development of biomaterials designed for specific applications is an important objective in personalized medicine. While the breadth and prominence of biomaterials have increased exponentially over the past decades, critical challenges remain to be addressed, particularly in the development of biomaterials that exhibit highly specific functions. These functional properties are often encoded within the molecular structure of the component molecules. Proteins, as a consequence of their structural specificity, represent useful substrates for the construction of functional biomaterials through rational design. This chapter provides an in-depth survey of biomaterials constructed from coiled-coils, one of the best-understood protein structural motifs. We discuss the utility of this structurally diverse and functionally tunable class of proteins for the creation of novel biomaterials. This discussion illustrates the progress that has been made in the development of coiled-coil biomaterials by showcasing studies that bridge the gap between the academic science and potential technological impact.

  19. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group; Summer 2005

    Energy Technology Data Exchange (ETDEWEB)

    2005-09-01

    The United States is home to more than 700 American Indian tribes and Native Alaska villages and corporations located on 96 million acres. Many of these tribes and villages have excellent wind resources that could be commercially developed to meet their electricity needs or for electricity export. The Wind Powering America program engages Native Americans in wind energy development, and as part of that effort, the NAWIG newsletter informs readers of events in the Native American/wind energy community.

  20. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group; Summer 2004

    Energy Technology Data Exchange (ETDEWEB)

    2004-07-01

    The United States is home to more than 700 American Indian tribes and Native Alaska villages and corporations located on 96 million acres. Many of these tribes and villages have excellent wind resources that could be commercially developed to meet their electricity needs or for electricity export. The Wind Powering America program engages Native Americans in wind energy development, and as part of that effort, the NAWIG newsletter informs readers of events in the Native American/wind energy community.

  1. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group; Summer 2006

    Energy Technology Data Exchange (ETDEWEB)

    2006-06-01

    The United States is home to more than 700 American Indian tribes and Native Alaska villages and corporations located on 96 million acres. Many of these tribes and villages have excellent wind resources that could be commercially developed to meet their electricity needs or for electricity export. The Wind Powering America program engages Native Americans in wind energy development, and as part of that effort, the NAWIG newsletter informs readers of events in the Native American/wind energy community.

  2. Cloning, overexpression, purification and crystallization of the CRN12 coiled-coil domain from Leishmania donovani.

    Science.gov (United States)

    Srivastava, Vijay Kumar; Rana, Ajay Kumar; Sahasrabuddhe, Amogh A; Gupta, C M; Pratap, J V

    2013-05-01

    Leishmania donovani coronin CRN12 is an actin-binding protein which consists of two domains: an N-terminal WD repeat domain and a C-terminal coiled-coil domain. The coiled-coil domain is 53 residues in length. Helix-helix interactions in general and coiled coils in particular are ubiquitous in the structure of proteins and play a significant role in the association among proteins, including supramolecular assemblies and transmembrane receptors that mediate cellular signalling, transport and actin dynamics. The L. donovani coronin CRN12 coiled-coil domain (5.8 kDa) was cloned, overexpressed, purified to homogeneity and the N-terminal 6×His tag was successfully removed by thrombin cleavage. Crystals of recombinant L. donovani coronin CRN12 coiled-coil domain were grown by vapour diffusion using a hanging-drop setup. Diffraction-quality crystals were obtained and data extending to 2.46 Å resolution were collected at 100 K on BM14, ESRF, Grenoble, France. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 118.0, b = 50.6, c = 46.0 Å, β = 111.0°. Matthews coefficient (VM) calculations suggested the presence of 4-6 molecules in the asymmetric unit, corresponding to a solvent content of ∼33-55%, and are consistent with self-rotation function calculations.

  3. Permanent magnet machine with windings having strand transposition

    Science.gov (United States)

    Qu, Ronghai; Jansen, Patrick Lee

    2009-04-21

    This document discusses, among other things, a stator with transposition between the windings or coils. The coils are free from transposition to increase the fill factor of the stator slots. The transposition at the end connections between an inner coil and an outer coil provide transposition to reduce circulating current loss. The increased fill factor reduces further current losses. Such a stator is used in a dual rotor, permanent magnet machine, for example, in a compressor pump, wind turbine gearbox, wind turbine rotor.

  4. Micro-fabrication of Flexible Coils with Copper Filled Through Polymer Via Structures

    International Nuclear Information System (INIS)

    Zhu, Q S; Zhang, Y; Itoh, T; Maeda, R; Toda, A

    2013-01-01

    In this work, we present one flexible 3D micro-coil. This 3D micro-coil is successfully prepared in a thin polymer film with a thickness of 120μm. The flexible coil is expected to be used in current sensing and energy harvesting MEMS those require a large deformation degree to wrap target object. A typical micro-machined 3D coil is composed of bottom, vertical and top windings. We firstly adopt through polymer vias (TPVs) and metal filling technology to fabricate the vertical windings. A high-speed copper electrodeposition technology of TPVs is developed to obtain void-free vertical windings

  5. COMPASS magnetic field coils and structure systems

    International Nuclear Information System (INIS)

    Crossland, R.T.; Booth, J.A.; Hayward, R.J.; Keogh, P.; Pratt, A.P.

    1987-01-01

    COMPASS is a new experimental toroidal assembly of compact design and with a wide range of physics objectives. It is required to operate either as a Tokamak or as a Reversed Field Pinch with interchangeable circular and dee-section vacuum vessels. The Toroidal field is produced by 16 rectangular coils of 4 turns with tapered conductors on the inside which nest together to form a vault to resist the centering forces. The coils are designed to produce a maximum field on axis of 2.1T which requires a current of 91 kA per turn. Two central solenoids and five pairs of coils symmetrically positioned above and below the machine equator provide the poloidal field. Both coil systems are supported form a mechanical support structure which surrounds the machine. This is primarily designed to resist out-of-plane forces on the TF coils but also acts as the base support for the PF coils and vacuum vessels. An illustration of the COMPASS Load Assembly is given and shows the D-shaped vacuum vessel, the major components and the various field windings

  6. Cooling and dehumidifying coils

    International Nuclear Information System (INIS)

    Murthy, M.V.K.

    1988-01-01

    The operating features of cooling and dehumidifying coils and their constructional details are discussed. The heat transfer relations as applicable to the boiling refrigerant and a single phase fluid are presented. Methods of accounting for the effect of moisture condensation on the air side heat transfer coefficient and the fin effectiveness are explained. The logic flow necessary to analyze direct expansion coils and chilled water coils is discussed

  7. Wind Energy

    International Nuclear Information System (INIS)

    Rodriguez D, J.M.

    1998-01-01

    The general theory of the wind energy conversion systems is presented. The availability of the wind resource in Colombia and the ranges of the speed of the wind in those which is possible economically to use the wind turbines are described. It is continued with a description of the principal technological characteristics of the wind turbines and are split into wind power and wind-powered pumps; and its use in large quantities grouped in wind farms or in autonomous systems. Finally, its costs and its environmental impact are presented

  8. The coiled coil motif in polymer drug delivery systems.

    Science.gov (United States)

    Pechar, Michal; Pola, Robert

    2013-01-01

    The coiled coil is a superhelical structural protein motif that has been thoroughly investigated in recent years. Because of the relatively well-understood principles that determine the properties of coiled coil peptides and proteins, macromolecular systems containing the coiled coil motif have been suggested for various applications. This short review focuses on hybrid polymer coiled coil systems designed for drug delivery purposes. After a short introduction, the most important features of the coiled coils (stability, association number, oligomerization selectivity and orientation of helices) are described, and the factors influencing these characteristics are discussed. Several examples of the most interesting biomedical applications of the polymer-coiled coil systems (according to the authors' opinion) are presented. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Improvements in or relating to superconductive coils

    International Nuclear Information System (INIS)

    Good, J.A.

    1976-01-01

    The windings of a superconducting coil may operate under great stress and movement of the conductors under this stress results in energy dissipation and since specific heats are small at the low temperatures required to induce superconductivity the resultant temperature rise may be sufficient to cause the superconducting properties of the conductor to be impaired. The usual solution to the problem is to employ substantial quantities of normal material in parallel with the superconductor to minimise such effects, but such coils are cumbersome and expensive to produce and operate, and are not suitable for generating intense field gradients. It has been proposed, as an alternative solution, to construct the winding so rigidly as to prevent the movement occurring. Simple potting in an epoxy resin is too brittle to withstand the large stresses. Another proposal involves glass fibre interleaving between layers of winding and then potting in epoxy resin, but this is not very satisfactory. In the arrangement described the winding is wrapped in at least one yard of glass fibre wound helically and the whole is impregnated with epoxy resin. A method for producing such a coil is described. (U.K.)

  10. Liquid rope coiling

    NARCIS (Netherlands)

    Ribe, N.M.; Habibi, M.; Bonn, D.

    2012-01-01

    A thin stream or rope of viscous fluid falling from a sufficient height onto a surface forms a steadily rotating helical coil. Tabletop laboratory experiments in combination with a numerical model for slender liquid ropes reveal that finite-amplitude coiling can occur in four distinct regimes

  11. Wind Farm Group Efficiency - A Sensitivity Analysis with a Mesoscale Model

    DEFF Research Database (Denmark)

    Volker, Patrick; Badger, Jake; Hahmann, Andrea N.

    2014-01-01

    In the North Sea the total installed capacity was in 2012 5GW, and it estimated that it will grow to 40GW by 2020 (EWEA). This will lead to an increasing wind farm density in regions with the most favourable conditions. In this study, we investigate the sensitivity of power density losses to wind...

  12. Molecular basis of coiled-coil oligomerization-state specificity.

    Science.gov (United States)

    Ciani, Barbara; Bjelic, Saša; Honnappa, Srinivas; Jawhari, Hatim; Jaussi, Rolf; Payapilly, Aishwarya; Jowitt, Thomas; Steinmetz, Michel O; Kammerer, Richard A

    2010-11-16

    Coiled coils are extensively and successfully used nowadays to rationally design multistranded structures for applications, including basic research, biotechnology, nanotechnology, materials science, and medicine. The wide range of applications as well as the important functions these structures play in almost all biological processes highlight the need for a detailed understanding of the factors that control coiled-coil folding and oligomerization. Here, we address the important and unresolved question why the presence of particular oligomerization-state determinants within a coiled coil does frequently not correlate with its topology. We found an unexpected, general link between coiled-coil oligomerization-state specificity and trigger sequences, elements that are indispensable for coiled-coil formation. By using the archetype coiled-coil domain of the yeast transcriptional activator GCN4 as a model system, we show that well-established trimer-specific oligomerization-state determinants switch the peptide's topology from a dimer to a trimer only when inserted into the trigger sequence. We successfully confirmed our results in two other, unrelated coiled-coil dimers, ATF1 and cortexillin-1. We furthermore show that multiple topology determinants can coexist in the same trigger sequence, revealing a delicate balance of the resulting oligomerization state by position-dependent forces. Our experimental results should significantly improve the prediction of the oligomerization state of coiled coils. They therefore should have major implications for the rational design of coiled coils and consequently many applications using these popular oligomerization domains.

  13. Divertor coil device

    International Nuclear Information System (INIS)

    Hanai, Satoru.

    1990-01-01

    The present invention concerns a divertor coil device used in a tokamak type thermonuclear device and the object thereof is to reduce thermal loads in the heat receiving portion. An auxiliary power source is disposed, in addition to a main power source, for supplying main electric current for changing electric current ratio between each of the divertor coils. Then, the null point for forming plasmas is made controllable. As a result, a power source for a part of coils connected to the auxiliary power source of the divertor coils can be changed by controlling the voltage of the auxiliary power source. Accordingly, the electric current distribution in the divertor coils is changed and the position for the null point high thermal load region can be moved laterally. The area of the heat receiving portion can be increased by moving the high thermal load region, thereby decreasing the thermal load density. (I.S.)

  14. Coil optimisation for transcranial magnetic stimulation in realistic head geometry.

    Science.gov (United States)

    Koponen, Lari M; Nieminen, Jaakko O; Mutanen, Tuomas P; Stenroos, Matti; Ilmoniemi, Risto J

    Transcranial magnetic stimulation (TMS) allows focal, non-invasive stimulation of the cortex. A TMS pulse is inherently weakly coupled to the cortex; thus, magnetic stimulation requires both high current and high voltage to reach sufficient intensity. These requirements limit, for example, the maximum repetition rate and the maximum number of consecutive pulses with the same coil due to the rise of its temperature. To develop methods to optimise, design, and manufacture energy-efficient TMS coils in realistic head geometry with an arbitrary overall coil shape. We derive a semi-analytical integration scheme for computing the magnetic field energy of an arbitrary surface current distribution, compute the electric field induced by this distribution with a boundary element method, and optimise a TMS coil for focal stimulation. Additionally, we introduce a method for manufacturing such a coil by using Litz wire and a coil former machined from polyvinyl chloride. We designed, manufactured, and validated an optimised TMS coil and applied it to brain stimulation. Our simulations indicate that this coil requires less than half the power of a commercial figure-of-eight coil, with a 41% reduction due to the optimised winding geometry and a partial contribution due to our thinner coil former and reduced conductor height. With the optimised coil, the resting motor threshold of abductor pollicis brevis was reached with the capacitor voltage below 600 V and peak current below 3000 A. The described method allows designing practical TMS coils that have considerably higher efficiency than conventional figure-of-eight coils. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Environmental assessment for the recycling of slightly activated copper coil windings from the 184-Inch Cyclotron at Lawrence Berkeley Laboratory, Berkeley, California

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-02

    The proposed action is to recycle slightly activated copper that is currently stored in a warehouse leased by Lawrence Berkeley Laboratory (LBL) to a scrap metal dealer. Subsequent reutilization of the copper would be unrestricted. This document addresses the potential environmental effects of recycling and reutilizing the activated copper. In addition, the potential environmental effects of possible future uses by the dealer are addressed. Direct environmental effects from the proposed action are assessed, such as air emissions from reprocessing the activated copper, as well as indirect beneficial effects, such as averting air emissions that would result from mining and smelting an equivalent quantity of copper ore. Evaluation of the human health impacts of the proposed action focuses on the pertinent issues of radiological doses and protection of workers and the public. Five alternatives to the proposed action are considered, and their associated potential impacts are addressed. The no-action alternative is the continued storage of the activated copper at the LBL warehouse. Two recycling alternatives are considered: recycling the activated copper at the Scientific Ecology Group (SEG) facility for re-use at a DOE facility and selling or giving the activated copper to a foreign government. In addition, two disposal alternatives evaluate the impacts attributable to disposing of the activated copper either at a local sanitary landfill or at the Hanford Low-Level Waste Burial Site. The proposed project and alternatives include no new construction or development of new industry.

  16. Open coil traction system.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2012-01-01

    Sliding mechanics have become a popular method for space closure, with the development of preadjusted edgewise appliances. Furthermore, various space closing auxiliaries have been developed and extensively evaluated for their clinical efficiency. Their effectiveness is enhanced with optimum force magnitude and low load deflection rate/force decay. With the advent of nickel-titanium (Ni-Ti) springs in orthodontics, load deflection rates have been markedly reduced. To use Ni-Ti springs, clinicians have to depend upon prefabricated closed coil springs. The open coil traction system, or open coil retraction spring, is developed utilizing Ni-Ti open coil springs for orthodontic space closure. This article describes the fabrication and clinical application of the open coil traction system, which has a number of advantages. It sustains a low load deflection rate with optimum force magnitude, and its design is adjustable for a desired length and force level. It is fail-safe for both activation and deactivation (ie, it cannot be overactivated, and the decompression limit of the open coil is controlled by the operator). The open coil traction system can be offset from the mucosa to help reduce soft tissue impingement.

  17. Commercial applications for COIL

    Science.gov (United States)

    Solomon, Wayne C.; Carroll, David L.; King, D. M.; Fockler, L. A.; Stromberg, D. S.; Sexauer, M.; Milmoe, A.; Sentman, Lee H.

    2000-01-01

    The chemical oxygen-iodine laser (COIL) is a high power, fiber deliverable tool, which can be used for a number of different industrial applications. COIL is of particular interest because of its short fiber deliverable wavelength, high scaleable continuous wave power, and excellent material interaction properties. In past research the University of Illinois at Urbana-Champaign identified and decommissioning and decontamination (DD) of nuclear facilities as a primary focus for COIL technology. DD will be a major challenge in the coming decades. The use of a robotically driven fiber delivered cutting/ablation tool in contaminated areas promises to lower risks to workers for the DD mission. Further, the high cutting speed of COIL will significantly reduce the time required to cut contaminated equipment, reducing costs. The high power of COIL will permit the dismantling of thick stacks of piping and equipment as well as reactor vessels. COIL is very promising for the removal of material from contaminated surfaces, perhaps to depths thicker than an inch. Laser cutting and ablation minimizes dust and fumes, which reduces the required number of high efficiency particulate accumulator filters, thus reducing costly waste disposal. Other potential industrial applications for COIL are shipbuilding, automotive manufacturing, heavy machinery manufacturing, tasks requiring underwater cutting or welding, and there appear to be very promising applications for high powers lasers in the oil industry.

  18. NAWIG News: The Quarterly Newsletter of the Native American Wind Interest Group, Spring 2008

    Energy Technology Data Exchange (ETDEWEB)

    Baranowski, R.

    2008-03-01

    The United States is home to more than 700 American Indian tribes and Native Alaska villages and corporations located on 96 million acres. Many of these tribes and villages have excellent wind resources that could be commercially developed to meet their electricity needs or for electricity export. The Wind Powering America program engages Native Americans in wind energy development, and as part of that effort, the NAWIG newsletter informs readers of events in the Native American/wind energy community. This issue features an interview with Steven J. Morello, director of DOE's newly formed Office of Indian Energy Policy and Programs, and a feature on the newly installed Vestas V-47 turbine at Turtle Mountain Community College.

  19. Coil spring venting arrangement

    International Nuclear Information System (INIS)

    McCugh, R.M.

    1975-01-01

    A simple venting device for trapped gas pockets in hydraulic systems is inserted through a small access passages, operated remotely, and removed completely. The device comprises a small diameter, closely wound coil spring which is pushed through a guide temporarily inserted in the access passage. The guide has a central passageway which directs the coil spring radially upward into the pocket, so that, with the guide properly positioned for depth and properly oriented, the coil spring can be pushed up into the top of the pocket to vent it. By positioning a seal around the free end of the guide, the spring and guide are removed and the passage is sealed

  20. Coiled-coils: The long and short of it.

    Science.gov (United States)

    Truebestein, Linda; Leonard, Thomas A

    2016-09-01

    Coiled-coils are found in proteins throughout all three kingdoms of life. Coiled-coil domains of some proteins are almost invariant in sequence and length, betraying a structural and functional role for amino acids along the entire length of the coiled-coil. Other coiled-coils are divergent in sequence, but conserved in length, thereby functioning as molecular spacers. In this capacity, coiled-coil proteins influence the architecture of organelles such as centrioles and the Golgi, as well as permit the tethering of transport vesicles. Specialized coiled-coils, such as those found in motor proteins, are capable of propagating conformational changes along their length that regulate cargo binding and motor processivity. Coiled-coil domains have also been identified in enzymes, where they function as molecular rulers, positioning catalytic activities at fixed distances. Finally, while coiled-coils have been extensively discussed for their potential to nucleate and scaffold large macromolecular complexes, structural evidence to substantiate this claim is relatively scarce. © 2016 The Authors BioEssays Published by WILEY Periodicals, Inc.

  1. Extending the self-assembly of coiled-coil hybrids

    NARCIS (Netherlands)

    Robson Marsden, Hana

    2009-01-01

    Of the various biomolecular building blocks in use in nature, coiled-coil forming peptides are amongst those with the most potential as building blocks for the synthetic self-assembly of nanostructures. Native coiled coils have the ability to function in, and influence, complex systems composed of

  2. Disruption of Bcr-Abl coiled coil oligomerization by design.

    Science.gov (United States)

    Dixon, Andrew S; Pendley, Scott S; Bruno, Benjamin J; Woessner, David W; Shimpi, Adrian A; Cheatham, Thomas E; Lim, Carol S

    2011-08-05

    Oligomerization is an important regulatory mechanism for many proteins, including oncoproteins and other pathogenic proteins. The oncoprotein Bcr-Abl relies on oligomerization via its coiled coil domain for its kinase activity, suggesting that a designed coiled coil domain with enhanced binding to Bcr-Abl and reduced self-oligomerization would be therapeutically useful. Key mutations in the coiled coil domain of Bcr-Abl were identified that reduce homo-oligomerization through intermolecular charge-charge repulsion yet increase interaction with the Bcr-Abl coiled coil through additional salt bridges, resulting in an enhanced ability to disrupt the oligomeric state of Bcr-Abl. The mutations were modeled computationally to optimize the design. Assays performed in vitro confirmed the validity and functionality of the optimal mutations, which were found to exhibit reduced homo-oligomerization and increased binding to the Bcr-Abl coiled coil domain. Introduction of the mutant coiled coil into K562 cells resulted in decreased phosphorylation of Bcr-Abl, reduced cell proliferation, and increased caspase-3/7 activity and DNA segmentation. Importantly, the mutant coiled coil domain was more efficacious than the wild type in all experiments performed. The improved inhibition of Bcr-Abl through oligomeric disruption resulting from this modified coiled coil domain represents a viable alternative to small molecule inhibitors for therapeutic intervention.

  3. Superconducting Coil of Po Dipole

    CERN Multimedia

    1983-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam P0. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench.After this successful test up to its nominal field of 4.2 T, the power was not raised to reach a quench. The magnet was not installed in a beam and had no other further use. Nevertheless its construction provided knowledges and experience which became useful in the design and construction of the LHC magnets. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8211532X.

  4. First assembly phase for the ATLAS toroid coils

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two double-pancake windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. In the first phase of assembly, the two 'pancakes' are packed into their vacuum vessel. This is done using bladders filled with resin and glass microbeads under pressure. The resin is heated and, once cooled, holds the pancakes in place. The operation has to be performed on both sides of the coil, which necessitated a special technique to turn the coils over and then transport them to the heating table. Photos 01, 02, 03: Transporting the coil to the heating table using a special lifting gantry manufactured at JINR-Dubna, Russia in preparation for the 'bladderisation' operation.

  5. A periodic table of coiled-coil protein structures.

    Science.gov (United States)

    Moutevelis, Efrosini; Woolfson, Derek N

    2009-01-23

    Coiled coils are protein structure domains with two or more alpha-helices packed together via interlacing of side chains known as knob-into-hole packing. We analysed and classified a large set of coiled-coil structures using a combination of automated and manual methods. This led to a systematic classification that we termed a "periodic table of coiled coils," which we have made available at http://coiledcoils.chm.bris.ac.uk/ccplus/search/periodic_table. In this table, coiled-coil assemblies are arranged in columns with increasing numbers of alpha-helices and in rows of increased complexity. The table provides a framework for understanding possibilities in and limits on coiled-coil structures and a basis for future prediction, engineering and design studies.

  6. Borehole induction coil transmitter

    Science.gov (United States)

    Holladay, Gale; Wilt, Michael J.

    2002-01-01

    A borehole induction coil transmitter which is a part of a cross-borehole electromagnetic field system that is used for underground imaging applications. The transmitter consists of four major parts: 1) a wound ferrite or mu-metal core, 2) an array of tuning capacitors, 3) a current driver circuit board, and 4) a flux monitor. The core is wound with several hundred turns of wire and connected in series with the capacitor array, to produce a tuned coil. This tuned coil uses internal circuitry to generate sinusoidal signals that are transmitted through the earth to a receiver coil in another borehole. The transmitter can operate at frequencies from 1-200 kHz and supplies sufficient power to permit the field system to operate in boreholes separated by up to 400 meters.

  7. LHC bending magnet coil

    CERN Multimedia

    A short test version of coil of wire used for the LHC dipole magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair.

  8. LHCb magnet coils arrive

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Each of the two coils for the LHCb magnet comprises 15 individual monolayer 'pancakes' of identical trapezoidal racetrack shape, and is bent at 45 degrees on the two transverse sides. Each pancake consists of eight turns of conductor, wound from a single length (approx. 290 m) of extruded aluminium. The coils have arrived at CERN; one of them is seen here being unloaded above the LHCb experimental cavern.

  9. Uniformly wound superconducting coil and method of making same

    Science.gov (United States)

    Mookerjee, Sumit; Weijun, Shen; Yager, Billy

    1994-01-01

    A coil of superconducting wire for a superconducting magnet having a relaely dense and uniformly spaced winding to enhance the homogeneity and strength of the magnetic field surrounding the coil and a method of winding the same wherein the mandrel used to wind said coil comprises removable spacers and retainers forming a plurality of outwardly opening slots, each of said slots extending generally about the periphery of the mandrel and being sized to receive and outwardly align and retain successive turns of the superconducting wire within each slot as the wire is wound around and laterally across the mandrel to form a plurality of wire ribbons of a predetermined thickness laterally across the mandrel.

  10. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Woolley, R.D.

    1987-01-01

    A new coil protection calculator (CPC) is presented in this paper. It is now being developed for TFTR's magnetic field coils will replace the existing coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPC will permit operation up to the actual coil limits by accurately and continuously computing coil parameters in real-time. The improvement will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates

  11. Hierarchical cascades of instability govern the mechanics of coiled coils: helix unfolding precedes coil unzipping.

    Science.gov (United States)

    Hamed, Elham; Keten, Sinan

    2014-07-15

    Coiled coils are a fundamental emergent motif in proteins found in structural biomaterials, consisting of α-helical secondary structures wrapped in a supercoil. A fundamental question regarding the thermal and mechanical stability of coiled coils in extreme environments is the sequence of events leading to the disassembly of individual oligomers from the universal coiled-coil motifs. To shed light on this phenomenon, here we report atomistic simulations of a trimeric coiled coil in an explicit water solvent and investigate the mechanisms underlying helix unfolding and coil unzipping in the assembly. We employ advanced sampling techniques involving steered molecular dynamics and metadynamics simulations to obtain the free-energy landscapes of single-strand unfolding and unzipping in a three-stranded assembly. Our comparative analysis of the free-energy landscapes of instability pathways shows that coil unzipping is a sequential process involving multiple intermediates. At each intermediate state, one heptad repeat of the coiled coil first unfolds and then unzips due to the loss of contacts with the hydrophobic core. This observation suggests that helix unfolding facilitates the initiation of coiled-coil disassembly, which is confirmed by our 2D metadynamics simulations showing that unzipping of one strand requires less energy in the unfolded state compared with the folded state. Our results explain recent experimental findings and lay the groundwork for studying the hierarchical molecular mechanisms that underpin the thermomechanical stability/instability of coiled coils and similar protein assemblies. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  12. On the interaction of wind and steep gravity wave groups using Miles' and Jeffreys' mechanisms

    Directory of Open Access Journals (Sweden)

    J. Touboul

    2008-12-01

    Full Text Available The interaction of wind and water wave groups is investigated theoretically and numerically. A steep wave train is generated by means of dispersive focusing, using both the linear theory and fully nonlinear equations. The linear theory is based on the Schrödinger equation while the nonlinear approach is developed numerically within the framework of the potential theory. The interaction between the chirped wave packet and wind is described by the Miles' mechanism. The differences between both approaches are discussed, and the influence of nonlinearity is emphasized. Furthermore, a different mechanism is considered, described by the modified Jeffreys' sheltering theory. From comparison between the two mechanisms, it is found that the persistence of the steep wave group depends on the physical model used, and is significantly increased when we use the latter mechanism.

  13. A COPRAS-F base multi-criteria group decision making approach for site selection of wind farm

    Directory of Open Access Journals (Sweden)

    Nikhil Chandra Chatterjee

    2013-01-01

    Full Text Available Today global warming is on the rise and the natural resources are getting consumed at a faster rate. Power consumption has increased many folds to cater the human need. Thus renewable energy resources are the only option available at this juncture. Wind energy is one of the renewable energy. Location selection for wind farm takes an important role on power generation. However, the location selection is a complex multicriteria problem due to the criteria factors which are conflicting in nature as well as uncertain. The process becomes more complex when a group of decision makers are involved in decision making. In the present study, a COPRAS (COmplex PRoportional ASsessment based multi-criteria decision-making (MCDM methodology is done under fuzzy environment with the help of multiple decision makers. More specifically, this study is aimed to focus the applicability of COPRAS-F as a strategic decision making tools to handle the group decision-making problems.

  14. First assembly phase for the ATLAS toroid coils

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The ATLAS barrel toroid system consists of eight coils, each of axial length 25.3 m, assembled radially and symmetrically around the beam axis. The coils are of a flat racetrack type with two double-pancake windings made of 20.5 kA aluminium-stabilized niobium-titanium superconductor. In the first phase of assembly, the two 'pancakes' are packed into their vacuum vessel. This is done using bladders filled with resin and glass microbeads under pressure. The resin is heated and, once cooled, holds the pancakes in place. The operation has to be performed on both sides of the coil, which necessitated a special technique to turn the coils over and then transport them to the heating table. Photos 01, 02, 03: Use of the overhead travelling crane to hoist the coil up and then tilt it over, the coil frame's metal feet being used as rotational pivots, supporting half the coil's weight. Once it has been turned over, the coil, now with only half the frame, is transported to the heating table using a special lifting gant...

  15. Study on Pole Arrangement of the CEDM Coils

    International Nuclear Information System (INIS)

    Park, Jin Seok; Lee, Myoung Goo; Kim, Hyun Min; Cho, Yeon Ho; Choi, Taek Sang

    2013-01-01

    The coil stack assembly is important for reliable operation of the CEDM, there have been efforts to improve the design by optimizing the design parameters such as dimensions and winding turns. However, magnetic forces of the CEDM can also change by different pole arrangement even if their design parameters are the same. Since the latch coil and lift coil are installed connected to each other, they produce magnetically coupled field when they are energized at the same time. This coupling field can affect the magnetic force of the CEDM significantly. In this paper, coil pole arrangement effects are studied. Electro-magnetic analysis is performed for the different pole arrangements of the CEDM coils to calculate the magnetic forces. Pole arrangement effects on magnetic forces were studied by static analysis of the CEDM magnetic field. Magnetic forces were calculated and compared for the two different pole arrangements of the coils. The results show that the magnetic poles of the lift coil and latch coil shall be arranged to have the same magnetic pole direction to achieve higher magnetic force

  16. An Air Bearing Rotating Coil Magnetic Measurement System

    CERN Document Server

    Gottschalk, Stephen C; Taylor, David J; Thayer, William

    2005-01-01

    This paper describes a rotating coil magnetic measurement system supported on air bearings. The design is optimized for measurements of 0.1micron magnetic centerline changes on long, small aperture quadrupoles. Graphite impregnated epoxy resin is used for the coil holder and coil winding forms. Coil holder diameter is 11 mm with a length between supports of 750mm. A pair of coils is used to permit quadrupole bucking during centerline measurements. Coil length is 616mm, inner radius 1.82mm, outer radius 4.74mm. The key features of the mechanical system are simplicity; air bearings for accurate, repeatable measurements without needing warm up time and a vibration isolated stand that uses a steel-topped Newport optical table with air suspension. Coil rotation is achieved by a low noise servo motor controlled by a standalone Ethernet servo board running custom servo software. Coil calibration procedures that correct wire placement errors, tests for mechanical resonances, and other system checks will also be discu...

  17. ISX toroidal field coil design and analysis

    International Nuclear Information System (INIS)

    Hussung, R.O.; Lousteau, D.C.; Johnson, N.E.; Weed, R.A.

    1975-01-01

    Structural design and analysis aspects of the toroidal field coils for the Impurity Study Experiment (ISX) tokamak are discussed. The overall mechanical design of ISX is predicated on the ability to remove the upper segment of the toroidal field coils to allow access to the toroidal vacuum vessel. The high current, 120 kA, capability of the new 74 MW power supply, coupled with the modest field requirement of ISX, allows the use of room temperature copper coils. Seventy-two turns, grouped into 18 coils, generate a magnet field of 18 kG at the major radius of 90 cm. Finite element structural analysis codes were utilized to determine the distribution of stresses and deflections around a typical turn. Initial material distribution on a coil was sized using the two-dimensional program FEATS. The resulting coil design was then coupled to the center bucking and out-of-plane restraint systems utilizing the NASTRAN code. The boundary conditions for the analytical models used in the two programs were then iterated, reaching satisfactory agreement as to stress contours and location for the joints

  18. AAFreqCoil: a new classifier to distinguish parallel dimeric and trimeric coiled coils.

    Science.gov (United States)

    Wang, Xiaofeng; Zhou, Yuan; Yan, Renxiang

    2015-07-01

    Coiled coils are characteristic rope-like protein structures, constituted by one or more heptad repeats. Native coiled-coil structures play important roles in various biological processes, while the designed ones are widely employed in medicine and industry. To date, two major oligomeric states (i.e. dimeric and trimeric states) of a coiled-coil structure have been observed, plausibly exerting different biological functions. Therefore, exploration of the relationship between heptad repeat sequences and coiled coil structures is highly important. In this paper, we develop a new method named AAFreqCoil to classify parallel dimeric and trimeric coiled coils. Our method demonstrated its competitive performance when benchmarked based on 10-fold cross validation and jackknife cross validation. Meanwhile, the rules that can explicitly explain the prediction results of the test coiled coil can be extracted from the AAFreqCoil model for a better explanation of user predictions. A web server and stand-alone program implementing the AAFreqCoil algorithm are freely available at .

  19. Multi-factor fiber coil temperature distribution model of FOG based on distributed fiber temperaturesensor

    Science.gov (United States)

    Feng, Wenshuai; Shi, Haiyang; Xu, Baoxiang; Ding, Dongfa

    2017-10-01

    In this paper, factors of fiber coil winding asymmetry, winding tension, non-ideal fiber type, adhensive glue type,and bonding way in fiber optic gyroscope could lead to fiber coils have different temperature distribution, and thermal induced nonreciprocity errors(Shupe errors). The influence of fiber coil temperature distribution in different wingding states on the fiber optic gyrocope temperature performance is studied in this paper, a temperatue distribution measure system of fiber coil is established, and the different wingding states coils are tested. Compared to the truly temperature distribution, the temperatue distribution measure model is exact relatively. The measure system can give more symmetrical and more uniform wingding state of fiber coil by meausure the temperatue distribution. Finally, the contrast experiment of fiber optic gyrocope is progressed, the experimental results agree well with the theory

  20. Superconducting coil protection

    International Nuclear Information System (INIS)

    Woods, E.L.

    1975-01-01

    The protection system is based on a two-phase construction program. Phase I is the development of a reliable hardwired relay control system with a digital loop utilizing firmware and a microprocessor controller. Phase II is an expansion of the digital loop to include many heretofore unmonitored coil variables. These new monitored variables will be utilized to establish early quench detection and to formulate confirmation techniques of the quench detection mechanism. Established quench detection methods are discussed and a new approach to quench detection is presented. The new circuit is insensitive to external pulsed magnetic fields and the associated induced voltages. Reliability aspects of the coil protection system are discussed with respect to shutdowns of superconducting coil systems. Redundance and digital system methods are presented as related topics

  1. Calibration of the Flow in the Test Section of the Research Wind Tunnel at DST Group

    Science.gov (United States)

    2015-10-01

    the tunnel. The calibration data are presented and analysed and explanations of flow behaviour are given. 2. Mean-Velocity Measurements 2.1...1073. Defence Science and Technology Organisation , Melbourne, Australia. Erm, L. P. 2003 Calibration of the flow in the extended test section...of the low-speed wind tunnel at DSTO. DSTO-TR-1384. Defence Science and Technology Organisation , Melbourne, Australia. Erm, L. P. 2015

  2. TESLA Coil Research

    Science.gov (United States)

    1992-05-01

    Sloan’s work was actually predated by the earlier work of Nikola Tesla . Sloan mistakenly identified " Tesla Coils" as lumped tuned resonators. The...Lefvw WsnJ L REPORT o]i 3. REPRT TYPE AND OATES COVEIRD May 1992 Special/Aug 1992 - May 1992 Z TITLE AND 5U§nUT S. FUNDING NUMIHRS Tesla Coil Research...STATEMENT 1211. ’ISTRIUUTION COOD Approved for public release; dis~ribution is unlimited 13. ABSTRACT (Masrmum 200 worw) High repetition rate Tesla

  3. Meiosis specific coiled-coil proteins in Shizosaccharomyces pombe

    Directory of Open Access Journals (Sweden)

    Okuzaki Daisuke

    2007-05-01

    Full Text Available Abstract Many meiosis-specific proteins in Schizosaccharomyces pombe contain coiled-coil motifs which play essential roles for meiotic progression. For example, the coiled-coil motifs present in Meu13 and Mcp7 are required for their function as a putative recombinase cofactor complex during meiotic recombination. Mcp6/Hrs1 and Mcp5/Num1 control horsetail chromosome movement by astral microtubule organization and anchoring dynein respectively. Dhc1 and Ssm4 are also required for horsetail chromosome movement. It is clear from these examples that the coiled-coil motif in these proteins plays an important role during the progression of cells through meiosis. However, there are still many unanswered questions on how these proteins operate. In this paper, we briefly review recent studies on the meiotic coiled-coil proteins in Sz. pombe.

  4. NET model coil test possibilities

    International Nuclear Information System (INIS)

    Erb, J.; Gruenhagen, A.; Herz, W.; Jentzsch, K.; Komarek, P.; Lotz, E.; Malang, S.; Maurer, W.; Noether, G.; Ulbricht, A.; Vogt, A.; Zahn, G.; Horvath, I.; Kwasnitza, K.; Marinucci, C.; Pasztor, G.; Sborchia, C.; Weymuth, P.; Peters, A.; Roeterdink, A.

    1987-11-01

    A single full size coil for NET/INTOR represents an investment of the order of 40 MUC (Million Unit Costs). Before such an amount of money or even more for the 16 TF coils is invested as much risks as possible must be eliminated by a comprehensive development programme. In the course of such a programme a coil technology verification test should finally prove the feasibility of NET/INTOR TF coils. This study report is almost exclusively dealing with such a verification test by model coil testing. These coils will be built out of two Nb 3 Sn-conductors based on two concepts already under development and investigation. Two possible coil arrangements are discussed: A cluster facility, where two model coils out of the two Nb 3 TF-conductors are used, and the already tested LCT-coils producing a background field. A solenoid arrangement, where in addition to the two TF model coils another model coil out of a PF-conductor for the central PF-coils of NET/INTOR is used instead of LCT background coils. Technical advantages and disadvantages are worked out in order to compare and judge both facilities. Costs estimates and the time schedules broaden the base for a decision about the realisation of such a facility. (orig.) [de

  5. Development work for the Japanese LCT coil and its design and construction

    International Nuclear Information System (INIS)

    Shimamoto, Susumu; Ando, Toshinari; Tsuji, Hiroshi; Yasukochi, Ko

    1984-01-01

    This paper describes design, verification tests, and construction of the Japanese test coil for the Large Coil Task (LCT). Japan Atomic Energy Research Institute (JAERI) signed on the LCT international agreement under the International Energy Agency (IEA) in 1978, and since then JAERI has been working to develop the Japanese LCT coil to explore the problems of design and construction of tokamak toroidal coil. Based on the common requirements of the LCT, the Japanese LCT coil was designed to be a pool-cooled NbTi fully-stabilized coil whose operating current is 10,220 A at 8 T. Through research and development of the Japanese LCT coil, new advances in the super-conducting coil technology were obtained, such as mechanically and chemically treated conductor surface that has high heat transfer about four times as much as usual ones, nitrogen-strengthened stainless steel that has the yield strength twice as much as usual stainless steel, NbTi filaments those have the critical current density twice as much as those before LCT, and so on. These advances have enabled to construct the Japanese LCT coil and it was completed in the spring of 1982. During the construction of the coil, new fabrication techniques were obtained to wind large current conductor into a mechanically rigid coil and thus to construct a totally stable large coil. (author)

  6. Construction and assembling of the trim coils for the Milan superconducting cyclotron

    International Nuclear Information System (INIS)

    Baccaglioni, G.; Cartegni, G.C.; Fusetti, M.; Gini, L.; Grilli, L.

    1986-01-01

    This paper presents the main characteristics of the trim coils realized for the heavy ions superconducting cyclotron under construction at the Milan University. The guidelines in the choice of the conductor size, of the insulation and cooling parameters are discussed in some details. The main operations in the coils construction, as winding, impregnation, electrical tests and assembling, are described

  7. High speed radiation scanning technique for simultaneously determining the pitch and eccentricity of an encased coil

    International Nuclear Information System (INIS)

    Foster, B.E.

    1976-01-01

    A method of determining the pitch and eccentricity of the winding of a coil unit is provided. It specifically relates to nondestructively examining completely encased heating coils used to simulate the heat generated from fuel rods in reactor studies. The method comprises (1) the use of an x-ray transmission technique through the axial centerline of the coil unit after the winding of the coil unit has been completely encased, (2) the use of a radiation detection instrument to monitor the transmitted radiation, and (3) the use of recording instrumentation calibrated as a function of the distance between windings. A change in the pitch of the winding is detected by a general increase or decrease in the distance between recorded peaks of the transmitted radiation. Eccentricity is detected by a consistent variation in distance between peaks occurring in alternate pairs. 1 claim, 5 figures

  8. Photonic crystal fiber coil sensor for water-depth sensing

    Science.gov (United States)

    Fan, Chen-Feng; Yu, Chin-Ping

    2013-05-01

    We fabricate a PCF coil sensor for water-depth sensing by winding a PCF on a plastic straw. Due to the bending-induced birefringence along the PCF, we can observe clear interference pattern in the output spectrum by placing the PCF coil into a Sagnac fiber loop. As we horizontally immerse the fabricated PCF coil into water, a nonlinear relationship between the water depth and the wavelength shift can be obtained. We have also measured the interference spectrum by vertically immersing the PCF coil into water. We can observe a linear relationship between the water depth and the wavelength shift, and the measured water-depth sensitivity for vertical immersion is -1.17 nm/mm.

  9. Progress of the ITER Correction Coils in China

    CERN Document Server

    Wei, J; Han, S; Yu, X; Du, S; Li, C; Fang, C; Wang, L; Zheng, W; Liu, L; Wen, J; Li, H; Libeyre, P; Dolgetta, N; Cormany, C; Sgobba, S

    2014-01-01

    The ITER Correction Coils (CC) include three sets of six coils each, distributed symmetrically around the tokamak to correct error fields. Each pair of coils, located on opposite sides of the tokamak, is series connected with polarity to produce asymmetric fields. The manufacturing of these superconducting coils is undergoing qualification of the main fabrication processes: winding into multiple pancakes, welding helium inlet/outlet on the conductor jacket, turn and ground insulation, vacuum pressure impregnation, inserting into an austenitic stainless steel case, enclosure welding, and assembling the terminal service box. It has been proceeding by an intense phase of R\\&D, trials tests, and final adjustment of the tooling. This paper mainly describes the progress in ASIPP for the CC manufacturing process before and on qualification phase and the status of corresponding equipment which are ordered or designed for each process. Some test results for the key component and procedure are also presented.

  10. Magnetic field calculation for Fermilab-style magnet coil end

    International Nuclear Information System (INIS)

    Ishibashi, K.; McInturff, A.D.

    1982-09-01

    A simple end field calculation is described, which utilizes a reciprocal theorem of mutual inductance between actual windings and a virtual coil. The calculation method is applied to a Fermilab-style magnet, and the computation results are compared with those obtained by GFUN

  11. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations.

    Science.gov (United States)

    Petrov, Petar I; Mandija, Stefano; Sommer, Iris E C; van den Berg, Cornelis A T; Neggers, Sebastiaan F W

    2017-01-01

    Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations. Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation. TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation.

  12. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations.

    Directory of Open Access Journals (Sweden)

    Petar I Petrov

    Full Text Available Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM, there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations.We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations.Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation.TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation.

  13. How much detail is needed in modeling a transcranial magnetic stimulation figure-8 coil: Measurements and brain simulations

    Science.gov (United States)

    Mandija, Stefano; Sommer, Iris E. C.; van den Berg, Cornelis A. T.; Neggers, Sebastiaan F. W.

    2017-01-01

    Background Despite TMS wide adoption, its spatial and temporal patterns of neuronal effects are not well understood. Although progress has been made in predicting induced currents in the brain using realistic finite element models (FEM), there is little consensus on how a magnetic field of a typical TMS coil should be modeled. Empirical validation of such models is limited and subject to several limitations. Methods We evaluate and empirically validate models of a figure-of-eight TMS coil that are commonly used in published modeling studies, of increasing complexity: simple circular coil model; coil with in-plane spiral winding turns; and finally one with stacked spiral winding turns. We will assess the electric fields induced by all 3 coil models in the motor cortex using a computer FEM model. Biot-Savart models of discretized wires were used to approximate the 3 coil models of increasing complexity. We use a tailored MR based phase mapping technique to get a full 3D validation of the incident magnetic field induced in a cylindrical phantom by our TMS coil. FEM based simulations on a meshed 3D brain model consisting of five tissues types were performed, using two orthogonal coil orientations. Results Substantial differences in the induced currents are observed, both theoretically and empirically, between highly idealized coils and coils with correctly modeled spiral winding turns. Thickness of the coil winding turns affect minimally the induced electric field, and it does not influence the predicted activation. Conclusion TMS coil models used in FEM simulations should include in-plane coil geometry in order to make reliable predictions of the incident field. Modeling the in-plane coil geometry is important to correctly simulate the induced electric field and to correctly make reliable predictions of neuronal activation PMID:28640923

  14. A large stellarator based on modular coils

    International Nuclear Information System (INIS)

    Hamberger, S.M.; Sharp, L.E.; Petersen, L.F.

    1979-06-01

    Although stellarators offer some considerable advantages over tokamaks, difficulties arise in designing large devices due, for instance, to poor plasma access as well as to constructional electromechanical and maintenance problems associated with continous helical windings. This paper describes a design for a fairly large device (major radius 2.1m), based on a set of discrete coil modules arranged in a toroidal configuration to provide the required closed magnetic surfaces, having gaps for unobstructed access to the plasma for diagnostics, etc, and allowing for easy removal for maintenance

  15. Coiled-coil networking shapes cell molecular machinery

    Science.gov (United States)

    Wang, Yongqiang; Zhang, Xinlei; Zhang, Hong; Lu, Yi; Huang, Haolong; Dong, Xiaoxi; Chen, Jinan; Dong, Jiuhong; Yang, Xiao; Hang, Haiying; Jiang, Taijiao

    2012-01-01

    The highly abundant α-helical coiled-coil motif not only mediates crucial protein–protein interactions in the cell but is also an attractive scaffold in synthetic biology and material science and a potential target for disease intervention. Therefore a systematic understanding of the coiled-coil interactions (CCIs) at the organismal level would help unravel the full spectrum of the biological function of this interaction motif and facilitate its application in therapeutics. We report the first identified genome-wide CCI network in Saccharomyces cerevisiae, which consists of 3495 pair-wise interactions among 598 predicted coiled-coil regions. Computational analysis revealed that the CCI network is specifically and functionally organized and extensively involved in the organization of cell machinery. We further show that CCIs play a critical role in the assembly of the kinetochore, and disruption of the CCI network leads to defects in kinetochore assembly and cell division. The CCI network identified in this study is a valuable resource for systematic characterization of coiled coils in the shaping and regulation of a host of cellular machineries and provides a basis for the utilization of coiled coils as domain-based probes for network perturbation and pharmacological applications. PMID:22875988

  16. Heterodimeric coiled-coil interactions of human GABAB receptor.

    Science.gov (United States)

    Burmakina, Svetlana; Geng, Yong; Chen, Yan; Fan, Qing R

    2014-05-13

    Metabotropic GABAB receptor is a G protein-coupled receptor that mediates inhibitory neurotransmission in the CNS. It functions as an obligatory heterodimer of GABAB receptor 1 (GBR1) and GABAB receptor 2 (GBR2) subunits. The association between GBR1 and GBR2 masks an endoplasmic reticulum (ER) retention signal in the cytoplasmic region of GBR1 and facilitates cell surface expression of both subunits. Here, we present, to our knowledge, the first crystal structure of an intracellular coiled-coil heterodimer of human GABAB receptor. We found that polar interactions buried within the hydrophobic core determine the specificity of heterodimer pairing. Disruption of the hydrophobic coiled-coil interface with single mutations in either subunit impairs surface expression of GBR1, confirming that the coiled-coil interaction is required to inactivate the adjacent ER retention signal of GBR1. The coiled-coil assembly buries an internalization motif of GBR1 at the heterodimer interface. The ER retention signal of GBR1 is not part of the core coiled-coil structure, suggesting that it is sterically shielded by GBR2 upon heterodimer formation.

  17. Study on load-bearing characteristics of a new pile group foundation for an offshore wind turbine.

    Science.gov (United States)

    Lang, Ruiqing; Liu, Run; Lian, Jijian; Ding, Hongyan

    2014-01-01

    Because offshore wind turbines are high-rise structures, they transfer large horizontal loads and moments to their foundations. One of the keys to designing a foundation is determining the sensitivities and laws affecting its load-bearing capacity. In this study, this procedure was carried out for a new high-rise cap pile group foundation adapted to the loading characteristics of offshore wind turbines. The sensitivities of influential factors affecting the bearing properties were determined using an orthogonal test. Through a combination of numerical simulations and model tests, the effects of the inclination angle, length, diameter, and number of side piles on the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity were determined. The results indicate that an increase in the inclination angle of the side piles will increase the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity. An increase in the length of the side piles will increase the vertical bearing capacity and bending bearing capacity. When the length of the side piles is close to the central pile, the increase is more apparent. Finally, increasing the number of piles will increase the horizontal bearing capacity; however, the growth rate is small because of the pile group effect.

  18. Study on Load-Bearing Characteristics of a New Pile Group Foundation for an Offshore Wind Turbine

    Science.gov (United States)

    Liu, Run; Lian, Jijian; Ding, Hongyan

    2014-01-01

    Because offshore wind turbines are high-rise structures, they transfer large horizontal loads and moments to their foundations. One of the keys to designing a foundation is determining the sensitivities and laws affecting its load-bearing capacity. In this study, this procedure was carried out for a new high-rise cap pile group foundation adapted to the loading characteristics of offshore wind turbines. The sensitivities of influential factors affecting the bearing properties were determined using an orthogonal test. Through a combination of numerical simulations and model tests, the effects of the inclination angle, length, diameter, and number of side piles on the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity were determined. The results indicate that an increase in the inclination angle of the side piles will increase the vertical bearing capacity, horizontal bearing capacity, and bending bearing capacity. An increase in the length of the side piles will increase the vertical bearing capacity and bending bearing capacity. When the length of the side piles is close to the central pile, the increase is more apparent. Finally, increasing the number of piles will increase the horizontal bearing capacity; however, the growth rate is small because of the pile group effect. PMID:25250375

  19. Electrospun Buckling Coils

    Science.gov (United States)

    Xin, Yu; Reneker, Darrell

    2009-03-01

    Electrospinning offers a useful way to produce fibers with micron and nanometer scale diameter. The present work deals with the buckling phenomenon characteristic of a jet impinging upon the surface of collector. A viscous jet may have either tensile or compressive forces along its axis. The periodic buckling that is often observed is attributed to the occurrence of compressive forces as the jet decelerates at the collector. With the increase of axial compressive stresses along the jet, a jet with circular cross sections first buckles by formation of sharp folds, and then by formation of coils. The resulting buckling patterns include zigzag patterns and coils that which can be controlled by changing parameters, such as density, viscosity, conductivity, voltage, polymer concentration, distance and volumetric flow rate. Uniformly buckled polymer fibers can be made at a rate of one turn per microsecond. An experimental apparatus was built to continuously collect buckling coils of nylon 6, from a water surface, into a multilayer sheet. These small ``springs'' and sheets will be tested for mechanical properties needed in biomedical applications.

  20. Development and fabrication of a Bi-2223 racetrack coil for generator applications

    International Nuclear Information System (INIS)

    Herd, K.G.; Salasoo, L.; Laskaris, E.T.; Ranze, R.A.; King, C.G.

    1996-01-01

    The development and fabrication of a layer-wound, epoxy-impregnated Bi-2223 high-temperature superconducting (HTS) racetrack coil which generates 40,000 ampere-turns of magnetomotive force (MMF) at 25 K is described. The coil was wound using Ag-sheathed Bi-2223 tape conductor laminated with copper foils for strength enhancement and insulated using a paper-wrap method. After epoxy impregnation, the coil was tested over a range of 16--25 K in a vacuum dewar using a closed-cycle helium refrigeration system. Descriptions of the tape lamination and insulation processing, the coil winding and impregnation, and the experimental test setup are given

  1. Role of the coiled-coil tip of Escherichia coli DksA in promoter control

    Science.gov (United States)

    Lee, Jeong-Hyun; Lennon, Christopher W.; Ross, Wilma; Gourse, Richard L.

    2012-01-01

    E. coli DksA works in conjunction with the small molecule ppGpp to regulate transcription initiation negatively or positively, depending on the identity of the promoter. DksA is in a class of transcription factors that do not bind directly to DNA like classical repressors or activators but rather bind in the RNA polymerase (RNAP) secondary channel like the transcription elongation factors GreA and GreB in E. coli and TFIIS in eukaryotes. We found that substitution for either of two residues in its coiled-coil tip, D74 or A76, eliminates DksA function without affecting its apparent affinity for RNAP. The properties of DksA-Gre factor chimeras indicated that the coiled-coil tip is responsible for the DksA-specific effects on open complex formation. A conservative substitution at position 74, D74E, resulted in a loss of DksA function in both negative and positive control, and an E44D substitution at the analogous position in GreA resulted in a gain of function in both negative and positive control. That a single methylene group has such an extraordinary effect on these transcription factors highlights the critical nature of the identity of coiled-coil tip interactions with RNAP for open complex formation. PMID:22200485

  2. Coiled-coil coactivators play a structural role mediating interactions in hypoxia-inducible factor heterodimerization.

    Science.gov (United States)

    Guo, Yirui; Scheuermann, Thomas H; Partch, Carrie L; Tomchick, Diana R; Gardner, Kevin H

    2015-03-20

    The hypoxia-inducible factor complex (HIF-α·aryl hydrocarbon receptor nuclear translocator (ARNT)) requires association with several transcription coactivators for a successful cellular response to hypoxic stress. In addition to the conventional global transcription coactivator CREB-binding protein/p300 (CBP/p300) that binds to the HIF-α transactivation domain, a new group of transcription coactivators called the coiled-coil coactivators (CCCs) interact directly with the second PER-ARNT-SIM (PAS) domain of ARNT (ARNT PAS-B). These less studied transcription coactivators play essential roles in the HIF-dependent hypoxia response, and CCC misregulation is associated with several forms of cancer. To better understand CCC protein recruitment by the heterodimeric HIF transcription factor, we used x-ray crystallography, NMR spectroscopy, and biochemical methods to investigate the structure of the ARNT PAS-B domain in complex with the C-terminal fragment of a coiled-coil coactivator protein, transforming acidic coiled-coil coactivator 3 (TACC3). We found that the HIF-2α PAS-B domain also directly interacts with TACC3, motivating an NMR data-derived model suggesting a means by which TACC3 could form a ternary complex with HIF-2α PAS-B and ARNT PAS-B via β-sheet/coiled-coil interactions. These findings suggest that TACC3 could be recruited as a bridge to cooperatively mediate between the HIF-2α PAS-B·ARNT PAS-B complex, thereby participating more directly in HIF-dependent gene transcription than previously anticipated. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. A novel method for determining and improving the quality of a quadrupolar fiber gyro coil under temperature variations.

    Science.gov (United States)

    Li, Zhihong; Meng, Zhuo; Liu, Tiegen; Yao, X Steve

    2013-01-28

    We introduce a parameter called pointing error thermal sensitivity (PETS) for quantitatively determining the quality of a quadrupolar (QAD) fiber coil under radial temperature variations. We show both analytically and experimentally that the pointing error of a fiber gyro incorporating the fiber coil is linearly proportional to the final radial thermal gradient on the coil, with PETS as the proportional constant. We further show that PETS is linearly proportional to another parameter called effective asymmetric length of the coil. By thermally inducing different radial thermal gradients on the fiber coil and measuring the corresponding pointing errors in a gyroscopic measurement setup, we can confidently determine the PETS of the fiber coil and its associated effective asymmetric length caused by imperfections in coil winding. Consequently, we are able to precisely trim the coil to achieve best thermal performance.

  4. The influence of stakeholder groups in operation and maintenance services of offshore wind farms

    DEFF Research Database (Denmark)

    Ahsan, Dewan; Pedersen, Søren

    2018-01-01

    the identified stakeholder group's interest and power to influence O&M, iii) to evaluate the relationship between different stakeholder groups and iv) to highlight potential strategies to manage the stakeholder groups. In this article, the stakeholder analysis approach is used. The results reveal that eleven key...... of the perception of losing business if they cooperate with their competitors. From the sustainability point of angel, achieving cooperative advantage is always preferable than competitive advantage....

  5. Mechanical behavior of the mirror fusion test Facility superconducting magnet coils

    International Nuclear Information System (INIS)

    Horvath, J.A.

    1980-01-01

    The mechanical response to winding and electromagnetic loads of the Mirror Fusion Test Facility (MFTF) superconducting coil pack is presented. The 375-ton (3300 N) MFTF Yin-Yang magnet, presently the world's largest superconducting magnet, is scheduled for acceptance cold-testing in May of 1981. The assembly is made up of two identical coils which together contain over 15 miles (24 km) of superconductor wound in 58 consecutive layers of 24 turns each. Topics associated with mechanical behavior include physical properties of the coil pack and its components, winding pre-load effects, finite element analysis, magnetic load redistribution, and the design impact of predicted conductor motion

  6. Expert group study on recommended practices for wind turbine testing and evaluation. 10. Measurement of noise immission from wind turbines at noise receptor locations

    International Nuclear Information System (INIS)

    Ljunggren, S.

    1997-01-01

    The purpose of this guide is to provide a set of techniques and methods for the measurement and description of wind turbine noise immission, that is, wind turbine noise at receptor locations. These techniques and methods have been prepared so that they can be used by: manufacturers; developers; operators; planning authorities; research and development engineers, for the purpose of verification of compliance with noise immission limits and of noise propagation models. The measurement of noise immission from wind turbines is a complex acoustic task. This guideline cannot cover all possible problems that may be encountered on, for instance: determination of wind speed; measurements in cases of low signal-to-noise ratio; allowance for reflections from buildings. Thus, it is strongly recommended that the measurements described in this guide are always carried out by experienced acousticians. (au)

  7. Prediction of Wind Environment and Indoor/Outdoor Relationships for PM2.5 in Different Building–Tree Grouping Patterns

    Directory of Open Access Journals (Sweden)

    Bo Hong

    2018-01-01

    Full Text Available Airflow behavior and indoor/outdoor PM2.5 dispersion in different building–tree grouping patterns depend significantly on the building–tree layouts and orientation towards the prevailing wind. By using a standard k-ε model and a revised generalized drift flux model, this study evaluated airflow fields and indoor/outdoor relationships for PM2.5 resulting from partly wind-induced natural ventilation in four hypothetical building–tree grouping patterns. Results showed that: (1 Patterns provide a variety of natural ventilation potential that relies on the wind influence, and buildings that deflect wind on the windward facade and separate airflow on the leeward facade have better ventilation potential; (2 Patterns where buildings and trees form a central space and a windward opening side towards the prevailing wind offer the best ventilation conditions; (3 Under the assumption that transported pollution sources are diluted through the inlet, the aerodynamics and deposition effects of trees cause the lower floors of a multi-storey building to be exposed to lower PM2.5 compared with upper floors, and lower indoor PM2.5 values were found close to the tree canopy; (4 Wind pressure differences across each flat showed a poor correlation (R2 = 0.059, with indoor PM2.5 concentrations; and (5 Patterns with the long facade of buildings and trees perpendicular to the prevailing wind have the lowest indoor PM2.5 concentrations.

  8. Careers in Wind Energy

    Science.gov (United States)

    Liming, Drew; Hamilton, James

    2011-01-01

    As a common form of renewable energy, wind power is generating more than just electricity. It is increasingly generating jobs for workers in many different occupations. Many workers are employed on wind farms: areas where groups of wind turbines produce electricity from wind power. Wind farms are frequently located in the midwestern, western, and…

  9. Large coil test structural analysis

    International Nuclear Information System (INIS)

    Clinard, J.A.; Hammonds, C.J.

    1986-01-01

    The International Fusion Superconducting Magnet Test Facility (IFSMTF) at Oak Ridge National Laboratory (ORNL) is being utilized for testing of 2.5 x 3.5-m bore superconducting 8-T magnets produced by four international agencies (U.S., Euratom, Japan, and Switzerland). The definitive tests in the design configuration, six coils arranged in a compact torus, will begin in late 1985. Partial-array tests involving one US coil and the Japanese coil were completed in the fall of 1984. This presentation describes structural analysis using NASTRAN, with symmetry and superelement techniques, to predict the IFSMTF test stand and coil responses to various combinations of in-plane and out-of-plane loading conditions for both the partial-array and six-coil test configurations. Comparison to partial-array displacement and strain measurements are presented and discussed. Six-coil results and their utilization for determining safe levels of operation of the system are likewise discussed

  10. Fabrication of an epoxy-insulated Marshall Coil

    International Nuclear Information System (INIS)

    Eaton, E.E.; Ehart, E.P.; Ebaugh, L.R.; Fox, A.G.; Dickinson, J.M.

    1977-01-01

    A Marshall Coil was fabricated by the LASL CMB-6 Materials Technology Group for use in an electrical testing program to evaluate the Marshall Coil concept. The coil is basically a hat-shaped epoxy insulator which was electroplated with copper on all surfaces, and a complex conductor pattern was machined out of the copper. The brim of the coil is approximately 84 cm diameter and the crown is 24 cm high. Other techniques for fabricating Marshall Coils were studied, the one selected being that which was felt to offer the best chance of success on a one-time basis. Alternate proposals involved (a) the potting of a freestanding copper insulator array in epoxy resin, and (b) inlaying stamped copper conductor sections in the slots of a machined epoxy insulator

  11. Suppression of m = 0 in a RFP by toroidal field coils

    International Nuclear Information System (INIS)

    Alexander, D.; Robertson, S.

    1993-01-01

    The Reversatron RFP is normally operated with the toroidal field coils connected in series. The time-integrated voltage applied to the circuit determines the sum of the fluxes linking each turn but not the flux within each turn. Each winding may have a different flux determined by the external drive and by currents within the plasma. A parallel connection of the field coils results in the flux within each coil being determined by the volt-seconds applied to the windings; thus the toroidal flux is the same within each coil. This configuration suppresses any toroidal variation in the toroidal flux and effectively reduces the level of the m = 0 component of the radial field. The m = 0 fluctuations are expected to arise due to nonlinear coupling of the m = 1 modes. A parallel connection of field coils is impractical due to the low impedance required for driving the coils. The authors have tested the effect of parallel connected coils by adding an auxiliary set of 36 coils. These are connected in parallel but are not connected to any supply. The toroidal flux is generated by the series-connected coils which generate voltage but not current in the parallel-connected coils. With the auxiliary coils, the discharge duration is increased from 500 to 550 μsec, the plasma current is increased from 50 kA to 60 kA, F is more negative, Θ is larger, and there is less shot-to-shot variation in the discharges. The m = 0 fluctuations measured by 43 surface coils are, however, only slightly reduced

  12. Triple Halo Coil: Development and Comparison with Other TMS Coils

    Science.gov (United States)

    Rastogi, Priyam; Hadimani, Ravi; Jiles, David

    Transcranial Magnetic Stimulation (TMS) is a non-invasive stimulation technique that can be used for the treatment of various neurological disorders such as Parkinson's Disease, PTSD, TBI and anxiety by regulating synaptic activity. TMS is FDA approved for the treatment of major depressive disorder. There is a critical need to develop deep TMS coils that can stimulate deeper regions of the brain without excessively stimulating the cortex in order to provide an alternative to surgical methods. We have developed a novel multi-coil configuration called ``Triple Halo Coil'' (THC) that can stimulate deep brain regions. Investigation of induced electric and magnetic field in these regions have been achieved by computer modelling. Comparison of the results due to THC configuration have been conducted with other TMS coils such as ``Halo Coil'', circular coil and ``Figure of Eight'' coil. There was an improvement of more than 15 times in the strength of magnetic field, induced by THC configuration at 10 cm below the vertex of the head when compared with the ``Figure of Eight'' coil alone. Carver Charitable Trust.

  13. High-resolution structures of a heterochiral coiled coil.

    Science.gov (United States)

    Mortenson, David E; Steinkruger, Jay D; Kreitler, Dale F; Perroni, Dominic V; Sorenson, Gregory P; Huang, Lijun; Mittal, Ritesh; Yun, Hyun Gi; Travis, Benjamin R; Mahanthappa, Mahesh K; Forest, Katrina T; Gellman, Samuel H

    2015-10-27

    Interactions between polypeptide chains containing amino acid residues with opposite absolute configurations have long been a source of interest and speculation, but there is very little structural information for such heterochiral associations. The need to address this lacuna has grown in recent years because of increasing interest in the use of peptides generated from d amino acids (d peptides) as specific ligands for natural proteins, e.g., to inhibit deleterious protein-protein interactions. Coiled-coil interactions, between or among α-helices, represent the most common tertiary and quaternary packing motif in proteins. Heterochiral coiled-coil interactions were predicted over 50 years ago by Crick, and limited experimental data obtained in solution suggest that such interactions can indeed occur. To address the dearth of atomic-level structural characterization of heterochiral helix pairings, we report two independent crystal structures that elucidate coiled-coil packing between l- and d-peptide helices. Both structures resulted from racemic crystallization of a peptide corresponding to the transmembrane segment of the influenza M2 protein. Networks of canonical knobs-into-holes side-chain packing interactions are observed at each helical interface. However, the underlying patterns for these heterochiral coiled coils seem to deviate from the heptad sequence repeat that is characteristic of most homochiral analogs, with an apparent preference for a hendecad repeat pattern.

  14. Coiled Coils Ensure the Physiological Ectodomain Shedding of Collagen XVII*

    Science.gov (United States)

    Nishie, Wataru; Jackow, Joanna; Hofmann, Silke C.; Franzke, Claus-Werner; Bruckner-Tuderman, Leena

    2012-01-01

    α-Helical coiled coils, frequent protein oligomerization motifs, are commonly observed in vital proteins. Here, using collagen XVII as an example, we provide evidence for a novel function of coiled coils in the regulation of ectodomain shedding. Transmembrane collagen XVII, an epithelial cell surface receptor, mediates dermal-epidermal adhesion in the skin, and its dysfunction is linked to human skin blistering diseases. The ectodomain of this collagen is constitutively shed from the cell surface by proteinases of a disintegrin and metalloprotease family; however, the mechanisms regulating shedding remain elusive. Here, we used site-specific mutagenesis to target the coiled-coil heptad repeats within the juxtamembranous, extracellular noncollagenous 16th A (NC16A) domain of collagen XVII. This resulted in a substantial increase of ectodomain shedding, which was not mediated by disintegrin and metalloproteases. Instead, conformational changes induced by the mutation(s) unmasked a furin recognition sequence that was used for cleavage. This study shows that apart from their functions in protein oligomerization, coiled coils can also act as regulators of ectodomain shedding depending on the biological context. PMID:22761443

  15. The coiled coil motif in polymer drug delivery systems

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Pola, Robert

    2013-01-01

    Roč. 31, č. 1 (2013), s. 90-96 ISSN 0734-9750 R&D Projects: GA ČR GA203/08/0543; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : coiled coil * hydrophilic polymer * recombinant protein Subject RIV: CD - Macromolecular Chemistry Impact factor: 8.905, year: 2013

  16. Competition between Coiled-Coil Structures and the Impact on Myosin-10 Bundle Selection.

    Science.gov (United States)

    Vavra, Kevin C; Xia, Youlin; Rock, Ronald S

    2016-06-07

    Coiled-coil fusions are a useful approach to enforce dimerization in protein engineering. However, the final structures of coiled-coil fusion proteins have received relatively little attention. Here, we determine the structural outcome of adjacent parallel and antiparallel coiled coils. The targets are coiled coils that stabilize myosin-10 in single-molecule biophysical studies. We reveal the solution structure of a short, antiparallel, myosin-10 coiled-coil fused to the parallel GCN4-p1 coiled coil. Surprisingly, this structure is a continuous, antiparallel coiled coil where GCN4-p1 pairs with myosin-10 rather than itself. We also show that longer myosin-10 segments in these parallel/antiparallel fusions are dynamic and do not fold cooperatively. Our data resolve conflicting results on myosin-10 selection of actin filament bundles, demonstrating the importance of understanding coiled-coil orientation and stability. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. CCHMM_PROF: a HMM-based coiled-coil predictor with evolutionary information

    DEFF Research Database (Denmark)

    Bartoli, Lisa; Fariselli, Piero; Krogh, Anders

    2009-01-01

    MOTIVATION: The widespread coiled-coil structural motif in proteins is known to mediate a variety of biological interactions. Recognizing a coiled-coil containing sequence and locating its coiled-coil domains are key steps towards the determination of the protein structure and function. Different...

  18. Non-conventional rule of making a periodically varying different-pole magnetic field in low-power alternating current electrical machines with using ring coils in multiphase armature winding

    Science.gov (United States)

    Plastun, A. T.; Tikhonova, O. V.; Malygin, I. V.

    2018-02-01

    The paper presents methods of making a periodically varying different-pole magnetic field in low-power electrical machines. Authors consider classical designs of electrical machines and machines with ring windings in armature, structural features and calculated parameters of magnetic circuit for these machines.

  19. Analysis for the thermal performance of a modified quadrupolar fiber coil

    Science.gov (United States)

    Zhang, Zhuo; Yu, Fei

    2018-01-01

    Among many factors contributing to fiber optic gyroscope performance, the quality of the fiber coil is one of the most important parts of it. This paper focuses on the disadvantage of cross-layer leap and sensitivity to outside temperature gradient of the present standard quadrupolar (QAD) fiber coil. The paper focuses on reducing the temperature gradient and improving the winding quality of the fiber coil to modify the original standard QAD winding pattern using methods of buffer layers and layer-by-layer leap. The buffer fiber is wound to the inner and outer sides of the fiber coil to reduce the temperature gradient of effective fiber; the layer-by-layer leap is used in place of the original cross-layer leap, and it may reduce bending and stresses variation when fiber leaping. Also, the fibers are arranged orderly to improve the fiber coil winding quality. In addition to building the mathematical model for fiber coil, the simulation and experiment are performed to verify that the improved QAD fiber coils have better thermal performance, and it helps to reduce thermal-induced drift error of a fiber optic gyroscope and improves its precision.

  20. "Slinky" coils for neuromagnetic stimulation.

    Science.gov (United States)

    Zimmermann, K P; Simpson, R K

    1996-04-01

    Future advances in neuromagnetic stimulation depend significantly on the design of coils with improved focality. Although in the absence of internal current sources, no true focusing of magnetically induced currents is possible, improvements in the focality of current concentrations passing through an area of biologic tissue are achievable through variations of the shape, orientation and size of neuromagnetic stimulating coils. The "butterfly" and the "4-leaf" coils are two examples of planar designs which achieve improved focality through centralization of the maximum coil current and peripheral distribution of the return currents. We introduce the "slinky" coil design as a 3-dimensional generalization of the principle of peripheral distribution of return currents and demonstrate its advantages over planar designs.

  1. Thermal analysis of COIL

    Science.gov (United States)

    Takeuchi, Noriyuki; Sugimoto, Daichi; Tei, Kazuyoku; Fujioka, Tomoo

    2004-05-01

    Analysis of heat release into operative gas of Chemical Oxygen Iodine Laser (COIL) is discussed. Pooling reaction of oxygen molecules in the excited state, the iodine dissociation process and the interaction of them with water vapor release energy of in the excited state oxygen molecules as heat energy. As results of heat release in the plenum, a rise of the total pressure as a rise of the total temperature is observed, and in the supersonic region a rise of static pressure and a decrease of total pressure as a rise of total temperature are observed. By following our analysis technique regarding pressure data of three different nozzles, the evaluations such as energy loss in a duct from a Singlet delta Oxygen Generator (SOG) and the number of dissipated oxygen molecules for the iodine dissociation can be estimated.

  2. Superconducting cyclotron magnet coil short

    International Nuclear Information System (INIS)

    Mallory, M.L.; Blosser, H.G.; Clark, D.J.; Launer, H.; Lawton, D.; Miller, P.; Resmini, F.

    1982-01-01

    In February 1981, a short circuit appeared in the superconducting coil of the K500 cyclotron. The short is resistive in character and therefore has no effect on steady state operation of the magnet. The resistance of the short varies, sometimes being below threshold of detection as a heat load on the cooling system and sometimes being significant. The resistance under certain conditions shows approximately cyclic phenomena with time constants in the range of seconds and other approximately cyclic phenomena which correlate with gross operating parameters of the magnet (shifting current from one coil to another at high field and lowering and raising the liquid helium level). A number of diagnostic studies of the short have been made, using 1) an array of flux sensing loops to sense the magnetic effect of the short, 2) voltage comparisons between upper and lower sections of the coil, 3) comparisons of forces in the nine member coil support system and 4) the effect of the short on the thermal charactersitics of the coil. Insulation failure or a metal chip shorting out turns have been explored in some detail but a convincing determination of the exact cause of the short may never be available, (even the extreme step of unwinding the coil having a significant probability that an imperfection with the observed characteristics would pass unnoticed). Analysis of the characteristics of the short indicated that the most serious consequence would be failure of the coils mechanical support system in the event that the magnet was quickly discharged, as in a dump or quench. To deal with this hazard, the support system has been modified by installing solid supports which prevent the coil from moving by an amount sufficient to damage the support system. We have also reexamined the data and calculations used in the original coil design and have made some additional measurements of the properties of the materials (yield strength, friction coefficient, Young's modulus) used in the

  3. The IEA Large Coil Task

    International Nuclear Information System (INIS)

    Beard, D.S.; Klose, W.; Shimamoto, S.; Vecsey, G.

    1988-01-01

    A multinational program of cooperative research, development, demonstrations, and exchanges of information on superconducting magnets for fusion was initiated in 1977 under an IEA agreement. The first major step in the development of TF magnets was called the Large Coil Task. Participants in LCT were the U.S. DOE, EURATOM, JAERI, and the Departement Federal de l'Interieur of Switzerland. The goals of LCT were to obtain experimental data, to demonstrate reliable operation of large superconducting coils, and to prove design principles and fabrication techniques being considered for the toroidal magnets of thermonuclear reactors. These goals were to be accomplished through coordinated but largely independent design, development, and construction of six test coils, followed by collaborative testing in a compact toroidal test array at fields of 8 T and higher. Under the terms of the IEA Agreement, the United States built and operated the test facility at Oak Ridge and provided three test coils. The other participants provided one coil each. Information on design and manufacturing and all test data were shared by all. The LCT team of each participant included a government laboratory and industrial partners or contractors. The last coil was completed in 1985, and the test assembly was completed in October of that year. Over the next 23 months, the six-coil array was cooled down and extensive testing was performed. Results were gratifying, as tests achieved design-point performance and well beyond. (Each coil reached a peak field of 9 T.) Experiments elucidated coil behavior, delineated limits of operability, and demonstrated coil safety. (orig./KP)

  4. Superconducting poloidal coils for STARFIRE commercial reactor

    International Nuclear Information System (INIS)

    Wang, S.T.; Evans, K. Jr.; Turner, L.R.; Huang, Y.C.; Prater, R.; Alcorn, J.

    1979-01-01

    STARFIRE is considered to be the tenth commercial tokamak power plant. A preliminary design study on its superconducting poloidal coil system is presented. Key features of the design studies are: the elimination of the ohmic heating coil; the trade-off studies of the equilibrium field coil locations; and the development of a conceptual design for the superconducting equilibrium field coils. Described are the 100 kA cryostable conductor design, the coil structure, and evaluation of the coil forces

  5. Periprocedural safety of aneurysm embolization with the Medina Coil System: the early human experience.

    Science.gov (United States)

    Turk, Aquilla S; Maia, Orlando; Ferreira, Christian Candido; Freitas, Diogo; Mocco, J; Hanel, Ricardo

    2016-02-01

    Intracranial saccular aneurysms, if untreated, carry a high risk of morbidity and mortality from intracranial bleeding. Embolization coils are the most common treatment. We describe the periprocedural safety and performance of the initial human experience with the next generation Medina Coil System. The Medina Coil System is a layered three-dimensional coil made from a radiopaque, shape set core wire, and shape memory alloy outer coil filaments. Nine aneurysms in five patients were selected for treatment with the Medina Coil System. Nine aneurysms in five patients, ranging from 5 to 17 mm in size in various locations, were treated with the Medina Coil System. No procedural or periprocedural complications were encountered. Procedure times, number of coils used to treat the aneurysm, and use of adjunctive devices were much less than anticipated if conventional coil technology had been used. The Medina Coil System is a next generation coil that combines all of the familiar and expected procedural safety and technique concepts associated with conventional coils. We found improved circumferential aneurysm filling, which may lead to improved long term outcomes, with fewer devices and faster operating times. 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/

  6. Safety and cost of stent-assisted coiling of unruptured intracranial aneurysms compared with coiling or clipping.

    Science.gov (United States)

    Frontera, Jennifer A; Moatti, Joseph; de los Reyes, Kenneth M; McCullough, Stephen; Moyle, Henry; Bederson, Joshua B; Patel, Aman

    2014-01-01

    Stent-assisted coiling (SAC) of unruptured intracranial aneurysms is a treatment alternative to clipping or coiling, although high complication and procedure-related mortality rates have been reported. A retrospective study was conducted of patients undergoing SAC, coiling or clipping of unruptured intracranial aneurysms between 2003 and 2010. Rates of residual aneurysm, recanalization, complications, cost (adjusted to 2010), length of stay (LOS) and outcome were compared between groups. Of 116 subjects, 47 underwent SAC, 33 coiling and 36 clipping. The groups were similar in age, gender and aneurysm location, although the SAC group had significantly larger aneurysms with wider necks (p=0.001). Patients who underwent SAC had more residual aneurysm after initial treatment than those treated with coiling or clipping (75%, 52% and 19%, respectively, p<0.0001), but this difference was smaller at follow-up angiography (50%, 50% and 17% residual, respectively) and was not significant after adjusting for baseline aneurysm and neck size. SAC was not associated with increased recanalization, requirement for additional treatment, mortality or complications after adjusting for aneurysm and neck size. Patients who underwent SAC and those who underwent coiling were more likely to have a good discharge disposition than patients treated with clipping (100% vs 91%, p=0.042). LOS was significantly shorter for patients who underwent SAC or coiling compared with those treated with clipping (p<0.0001). The overall direct cost was higher for patients who underwent SAC than for those treated with coiling or clipping (median $22 544 vs $12 933 vs $14 656, p=0.001), even after adjusting for aneurysm and neck size, LOS and retreatment. SAC is a safe alternative to coiling or clipping of unruptured aneurysms but it is currently more expensive.

  7. Coil end design for the LHC dipole magnet

    International Nuclear Information System (INIS)

    Brandt, J.S.

    1996-01-01

    This paper describes the design of the coil ends for the Large Hadron Collider dipole magnets of the CERN European Laboratory for Particle Physics in Switzerland. This alternative to existing European designs was provided by Fermi National Accelerator Laboratory by agreement between CERN and the United States. The superconducting cable paths are determined from both magnetic and mechanical considerations. The coil end parts used to shape and constrain the conductors in the coil ends are designed using the developable surface, grouped end approach. This method allows the analysis of strain energy within the conductor groups, and the optimization of mechanical factors during the design. Design intent and implementation are discussed. Inner and outer coil design challenges and end analysis are detailed

  8. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Lawson, J.E.; Persing, R.G.; Senko, T.R.; Woolley, R.D.

    1989-01-01

    A new coil protection system (CPS) is being developed to replace the existing TFTR magnetic coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPS, when installed in October of 1988, will permit operation up to the actual coil stress limits parameters in real-time. The computation will be done in a microprocessor based Coil Protection Calculator (CPC) currently under construction at PPL. THe new CPC will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates. The CPC will provide real-time estimates of critical coil and bus temperatures and stresses based on real-time redundant measurements of coil currents, coil cooling water inlet temperature, and plasma current. The critical parameter calculations are compared to prespecified limits. If these limits are reached or exceeded, protection action will be initiated to a hard wired control system (HCS), which will shut down the power supplies. The CPC consists of a redundant VME based microprocessor system which will sample all input data and compute all stress quantities every ten milliseconds. Thermal calculations will be approximated every 10ms with an exact solution occurring every second. The CPC features continuous cross-checking of redundant input signal, automatic detection of internal failure modes, monitoring and recording of calculated results, and a quick, functional verification of performance via an internal test system. (author)

  9. Is umbilical coiling genetically determined?

    Science.gov (United States)

    Ayala, Nina K; Ernst, Linda M; Miller, Emily S

    2018-02-21

    Abnormal umbilical cord coiling is associated with adverse perinatal outcomes; however, the etiology of the umbilical coiling pattern is poorly understood. Retrospective cohort of all twin deliveries >20 weeks in 2014. Pregnancies were dichotomized by chorionicity and the umbilical coiling index (UCI) and placental cord insertion location were compared. In cases with one or both cords hypercoiled, the direction and pattern of coiling were compared by chorionicity. A similar analysis was performed stratified by zygosity. Three hundred sisty two twin pairs were included; 26 (7.2%) monochorionic and 174 (87.0%) definitively dizygotic. Concordance in the UCI and coiling category were similar between dichorionic and monochorionic as well as dizygous and monozygous gestations, (73.2% vs 80.8%, p = 0.399 and 71.4% vs 80.8%, p = 0.399, respectively). Analyses of the coiling direction and pattern also demonstrated no difference by chorionicity or zygosity. These data do not support a genetic basis for umbilical cord coiling.

  10. An improved current potential method for fast computation of stellarator coil shapes

    Science.gov (United States)

    Landreman, Matt

    2017-04-01

    Several fast methods for computing stellarator coil shapes are compared, including the classical NESCOIL procedure (Merkel 1987 Nucl. Fusion 27 867), its generalization using truncated singular value decomposition, and a Tikhonov regularization approach we call REGCOIL in which the squared current density is included in the objective function. Considering W7-X and NCSX geometries, and for any desired level of regularization, we find the REGCOIL approach simultaneously achieves lower surface-averaged and maximum values of both current density (on the coil winding surface) and normal magnetic field (on the desired plasma surface). This approach therefore can simultaneously improve the free-boundary reconstruction of the target plasma shape while substantially increasing the minimum distances between coils, preventing collisions between coils while improving access for ports and maintenance. The REGCOIL method also allows finer control over the level of regularization, it preserves convexity to ensure the local optimum found is the global optimum, and it eliminates two pathologies of NESCOIL: the resulting coil shapes become independent of the arbitrary choice of angles used to parameterize the coil surface, and the resulting coil shapes converge rather than diverge as Fourier resolution is increased. We therefore contend that REGCOIL should be used instead of NESCOIL for applications in which a fast and robust method for coil calculation is needed, such as when targeting coil complexity in fixed-boundary plasma optimization, or for scoping new stellarator geometries.

  11. Coiled Coils - A Model System for the 21st Century.

    Science.gov (United States)

    Lupas, Andrei N; Bassler, Jens

    2017-02-01

    α-Helical coiled coils were described more than 60 years ago as simple, repetitive structures mediating oligomerization and mechanical stability. Over the past 20 years, however, they have emerged as one of the most diverse protein folds in nature, enabling many biological functions beyond mechanical rigidity, such as membrane fusion, signal transduction, and solute transport. Despite this great diversity, their structures can be described by parametric equations, making them uniquely suited for rational protein design. Far from having been exhausted as a source of structural insight and a basis for functional engineering, coiled coils are poised to become even more important for protein science in the coming decades. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Cross-linking reveals laminin coiled-coil architecture

    Science.gov (United States)

    Armony, Gad; Jacob, Etai; Moran, Toot; Levin, Yishai; Mehlman, Tevie; Levy, Yaakov; Fass, Deborah

    2016-01-01

    Laminin, an ∼800-kDa heterotrimeric protein, is a major functional component of the extracellular matrix, contributing to tissue development and maintenance. The unique architecture of laminin is not currently amenable to determination at high resolution, as its flexible and narrow segments complicate both crystallization and single-particle reconstruction by electron microscopy. Therefore, we used cross-linking and MS, evaluated using computational methods, to address key questions regarding laminin quaternary structure. This approach was particularly well suited to the ∼750-Å coiled coil that mediates trimer assembly, and our results support revision of the subunit order typically presented in laminin schematics. Furthermore, information on the subunit register in the coiled coil and cross-links to downstream domains provide insights into the self-assembly required for interaction with other extracellular matrix and cell surface proteins. PMID:27815530

  13. Design of Correction Coil for ITER

    International Nuclear Information System (INIS)

    Kubo, Hiroatsu; Yoshida, Kiyoshi; Omine, Takeshi

    1998-11-01

    ITER (International Thermonuclear Experimental Reactor) project is under way among EU, Japan, Russia and US. In order to shut plasma, the magnetic field is applied by the superconducting coils in ITER. The coils which are called 'Poloidal field (PF-coil)' are installed to control the location and the cross-section shape for plasma in the vacuum vessel. Incorrect position of Magnetic field (Magnetic error) is occurred by the manufacture tolerance for PF-coil. The coils which are called 'Correction-Coil' are installed in order to correct these magnetic error around the PF-coil. The Correction Coils are consist of the 3-sets of the superconducting coil. The stress analysis for the correction coils is performed and the supporting structure of the coils are designed. The bolts for clamps and the position for clamps are examined from this analysis. (J.P.N.)

  14. A new twist in the coil: functions of the coiled-coil domain of structural maintenance of chromosome (SMC) proteins.

    Science.gov (United States)

    Matityahu, Avi; Onn, Itay

    2018-02-01

    The higher-order organization of chromosomes ensures their stability and functionality. However, the molecular mechanism by which higher order structure is established is poorly understood. Dissecting the activity of the relevant proteins provides information essential for achieving a comprehensive understanding of chromosome structure. Proteins of the structural maintenance of chromosome (SMC) family of ATPases are the core of evolutionary conserved complexes. SMC complexes are involved in regulating genome dynamics and in maintaining genome stability. The structure of all SMC proteins resembles an elongated rod that contains a central coiled-coil domain, a common protein structural motif in which two α-helices twist together. In recent years, the imperative role of the coiled-coil domain to SMC protein activity and regulation has become evident. Here, we discuss recent advances in the function of the SMC coiled coils. We describe the structure of the coiled-coil domain of SMC proteins, modifications and interactions that are mediated by it. Furthermore, we assess the role of the coiled-coil domain in conformational switches of SMC proteins, and in determining the architecture of the SMC dimer. Finally, we review the interplay between mutations in the coiled-coil domain and human disorders. We suggest that distinctive properties of coiled coils of different SMC proteins contribute to their distinct functions. The discussion clarifies the mechanisms underlying the activity of SMC proteins, and advocates future studies to elucidate the function of the SMC coiled coil domain.

  15. A miniature implantable coil that can be wrapped around a tubular organ within the human body

    Science.gov (United States)

    Mao, Shitong; Wang, Hao; Mao, Zhi-Hong; Sun, Mingui

    2018-05-01

    There are many tubular or rod-shaped organs and tissues within the human body. A miniature medical implant that wraps around such a biological structure can monitor or modulate its function. In order to provide the wrap-around implant with power, a solenoidal coil coupled wirelessly with a planar coil outside the human body can be used. Unfortunately, there is a serious practical problem that this configuration cannot be realized easily because the implantable solenoidal coil cannot be positioned around the tubular biological structure unless either the structure or the coil is cut and reconnected, which is impermissible in most cases. In addition, when a planner exterior coil is used for wireless power transfer and communication, its maximum magnetic coupling with the implanted solenoidal coil is achieved when the tubular structure is perpendicular to the surface of the body. However, in human anatomy, most tubular/rod structures are oriented horizontally. In order to solve these problems, we present a new flexible coil for the class of wrapped-around implantable devices. Our multilayer coil has specially designed windings in cross patterns. The new coil can be made conveniently in high precision at low cost on a flat substrate using the same technology for making the flexible multilayer printed circuit boards along with miniature sensors and electronic circuits. This allows the implant to be made in a flat form and then wrapped around the biostructure during surgery. We present the design of this new coil, perform theoretical analysis with respect to its wireless power transfer efficiency, discuss the effects of coil parameters, and conduct experiments using constructed miniature prototypes. Our results confirm the validity of the new coil.

  16. Symmetry evaluation for an interferometric fiber optic gyro coil utilizing a bidirectional distributed polarization measurement system.

    Science.gov (United States)

    Peng, Feng; Li, Chuang; Yang, Jun; Hou, Chengcheng; Zhang, Haoliang; Yu, Zhangjun; Yuan, Yonggui; Li, Hanyang; Yuan, Libo

    2017-07-10

    We propose a dual-channel measurement system for evaluating the optical path symmetry of an interferometric fiber optic gyro (IFOG) coil. Utilizing a bidirectional distributed polarization measurement system, the forward and backward transmission performances of an IFOG coil are characterized simultaneously by just a one-time measurement. The simple but practical configuration is composed of a bidirectional Mach-Zehnder interferometer and multichannel transmission devices connected to the IFOG coil under test. The static and dynamic temperature results of the IFOG coil reveal that its polarization-related symmetric properties can be effectively obtained with high accuracy. The optical path symmetry investigation is highly beneficial in monitoring and improving the winding technology of an IFOG coil and reducing the nonreciprocal effect of an IFOG.

  17. First coil for the SC

    CERN Multimedia

    CERN PhotoLab

    1955-01-01

    The coils for the SC magnet were stored in the large hangar of the Cointrin Airport (to make sure that they would be available before snow and ice would block the roads and canals from Belgium, where they were built).

  18. Coil for LEAR extraction septum

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    Which way does the current flow ? This intriguing object is the coil for the LEAR extraction septum. There were two septa, first a thin one, then this one, not so thin, somewhat on the borderline between septum and bending magnet.

  19. An approach to selecting the optimal sensing coil configuration structure for switched reluctance motor rotor position measurement

    Science.gov (United States)

    Cai, Jun; Deng, Zhiquan

    2015-02-01

    Accurate rotor position signal is highly required for controlling the switched reluctance motor (SRM). The use of galvanic isolated sensing coils can provide independent circuit for position estimation without affecting the SRM actuation. However, the cross-coupling between main winding and sensing coil, and the mutual coupling between adjacent phase sensing coils may affect the position estimation performance seriously. In this paper, three sensing coil configurations in a 12/8 structure SRM are analyzed and compared for selecting an optimal configuration that can effectively minimize the bad effects of the cross-coupling factors. The finite element analysis and experimental results are provided for verification.

  20. Simple Coiling versus Stent-Assisted Coiling of Paraclinoid Aneurysms: Radiological Outcome in a Single Center Study.

    Science.gov (United States)

    Kim, Soo Yeon; Park, Dong Sun; Park, Hye Yin; Chun, Young Il; Moon, Chang Taek; Roh, Hong Gee

    2017-11-01

    Paraclinoid aneurysms are a group of aneurysms arising at the distal internal carotid artery. Due to a high incidence of small, wide-necked aneurysms in this zone, it is often challenging to achieve complete occlusion when solely using detachable coils, thus stent placement is often required. In the present study, we aimed to investigate the effect of stent placement in endovascular treatment of paraclinoid aneurysms. Data of 98 paraclinoid aneurysms treated by endovascular approach in our center from August 2005 to June 2016 were retrospectively reviewed. They were divided into two groups: simple coiling and stent-assisted coiling. Differences in the recurrence and progressive occlusion between the two groups were mainly analyzed. The recurrence was defined as more than one grade worsening according to Raymond-Roy Classification or major recanalization that is large enough to permit retreatment in the follow-up study compared to the immediate post-operative results. Complete occlusion was achieved immediately after endovascular treatment in eight out of 37 patients (21.6%) in the stent-assisted group and 18 out of 61 (29.5%) in the simple coiling group. In the follow-up imaging studies, the recurrence rate was lower in the stent-assisted group (one out of 37, 2.7%) compared to the simple coiling group (13 out of 61, 21.3%) ( p =0.011). Multivariate logistic regression model showed lower recurrence rate in the stent-assisted group than the simple coiling group (odds ratio [OR] 0.051, 95% confidence interval [CI] 0.005-0.527). Furthermore there was also a significant difference in the rate of progressive occlusion between the stent-assisted group (16 out of 29 patients, 55.2%) and the simple coiling group (10 out of 43 patients, 23.3%) ( p =0.006). The stent-assisted group also exhibited a higher rate of progressive occlusion than the simple coiling group in the multivariate logistic regression model (OR 3.208, 95% CI 1.106-9.302). Use of stents results in good

  1. Two-Slotted Surface Coil Array for Magnetic Resonance Imaging at 4 Tesla

    International Nuclear Information System (INIS)

    Solis, S. E.; Hernandez, J. A.; Rodriguez, A. O.; Tomasi, D.

    2008-01-01

    Arrays of antennas have been widely accepted for magnetic resonance imaging applications due to their high signal-to-noise ratio (SNR) over large volumes of interest. A new surface coil based on the magnetron tube and called slotted surface coil, has been recently introduced by our group. This coil design experimentally demonstrated a significant improvement over the circular-shaped coil when used in the receive-only mode. The slotted coils formed a two-sheet structure with a 90 deg. separation and each coil had 6 circular slots. Numerical simulations were performed using the finite element method for this coil design to study the behaviour of the array magnetic field. Then, we developed a two-coil array for brain magnetic resonance imaging to be operated at the resonant frequency of 170 MHz in the transceiver mode. Phantom images were acquired with our coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. Numerical simulations demonstrated that electromagnetic interaction between the coil elements is negligible, and that the magnetic field showed a good uniformity. In vitro images showed the feasibility of this coil array for standard pulses for high field magnetic resonance imaging

  2. Design features of the A-cell and transition coils of MFTF-B

    International Nuclear Information System (INIS)

    Tatro, R.E.; Wohlwend, J.W.; Ring, D.S.

    1981-01-01

    The MFTF-B transition coil and A-cell magnet designs use variations of the copper-stabilized NbTi conductor developed by LLNL for the MFTF Yin-Yang magnets. This conductor will be wound on the one inch thick (12.7 mm) stainless steel coil forms using a two-axis winding machine similar to the existing LLNL Yin-Yang winding machine. After winding, covers will be placed over the coil and welded to the coil form to form a helium-tight jacket around the conductor. These jacketed coils are then enclosed in thick structural cases that react the large Lorentz forces on the magnets. The space between the coil jacket and case will be filled by a stainless steel bladder that will be injected with urethane. The injection bladder will provide cooling passages during cooldown as well as transmitting the Lorentz forces between the jacket and the case. The large self-equilibrating lobe-spreading forces on the magnets (29.10 6 lb, 127.0 MN) for the A-cell are reacted primarily through the thick 304 LN case into the external superstructure. The net Lorentz forces and the inertial forces on the magnet are reacted through support systems into the LLNL vacuum vessel structure

  3. Coil supporting device in nuclear fusion apparatus

    International Nuclear Information System (INIS)

    Hoshi, Ryo; Imura, Yasuya.

    1974-01-01

    Object: To secure intermediate fittings with a coil fixed thereon by an insulating tape to a fixed body by means of fittings, thereby supporting the coil in a narrow space. Structure: A coil is secured to intermediate fittings by means of an insulating tape, after which the intermediate fittings is mounted on a fixed body through fittings to support the coil in a narrow clearance portion between a plasma sealed vessel and a main coil. (Kamimura, M.)

  4. Mechanical and electric characteristics of vacuum impregnated no-insulation HTS coil

    International Nuclear Information System (INIS)

    Park, Heecheol; Kim, A-rong; Kim, Seokho; Park, Minwon; Kim, Kwangmin; Park, Taejun

    2014-01-01

    Highlights: • A single pancake no-insulation coil was fabricated with a brass lamination conductor. • Charging/discharging test was performed using liquid nitrogen and conduction-cooling. • Consistent contact resistance was verified after epoxy impregnation. • Equivalent circuit was used to estimate the heat generation during charging operation. • The HTS coil did not showed delamination problem for the conduction cooling. - Abstract: For the conduction cooling application, epoxy impregnation is inevitable to enhance the thermal conduction. However, there have been several research results on the delamination problem with coated conductor and the main cause of the delamination is related with the different thermal contraction between epoxy, the insulation layer and the weak conductor. To avoid this problem, the amount of epoxy and insulation layer between conductors should be minimized or removed. Therefore, no insulation (NI) winding method and impregnation after dry winding can be considered to solve the problem. The NI coil winding method is very attractive due to high mechanical/thermal stability for the special purpose of DC magnets by removing the insulation layer. In this paper, the NI coil winding method and vacuum impregnation are applied to a HTS coil to avoid the delamination problem and enhance the mechanical/thermal stability for the conduction cooling application. Through the charging/discharging operation, electric/thermal characteristics are investigated at 77 K and 30 K

  5. Manufacture of the poloidal field conductor insert coil (PFCI)

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W. [EFDA CSU Garching, Boltzmannstrasse 2, 85748 Garching bei Muenchen (Germany); Keefe, C. [Tesla Engineering, Storrington, Sussex (United Kingdom); Rajainmaeki, H. [EFDA CSU Garching, Boltzmannstrasse 2, 85748 Garching bei Muenchen (Germany)], E-mail: hannu.rajainmaki@tech.efda.org; Salpietro, E. [EFDA CSU Garching, Boltzmannstrasse 2, 85748 Garching bei Muenchen (Germany)

    2007-10-15

    Within the framework of the R and D programme for international thermonuclear experimental reactor (ITER) the European team European Fusion Development Agreement (EFDA) has been charged with the design and manufacture of the poloidal field conductor insert coil (PFCI). The purpose of the PFCI is to test and demonstrate the performance of long-length full-scale NbTi conductors in ITER-relevant conditions. The PFCI will be tested in the central solenoid model coil test facility at the JAEA, Naka, Japan. This paper details the complete manufacturing of the PFCI including development, forming machining, pre-assembly, impregnation, final assembly and testing. The PFCI is a single-layered wound solenoid of nine turns with a transition joggle in the centre section of the winding and an intermediate joint connection between the upper termination and the main coil winding. To give the required overall dimensions to fit in the testing facility, preformed and machined glass resin composite filler pieces are assembled with the winding and is finally vacuum pressure impregnated (VPI) to create a single assembly unit. The PFCI is enclosed for assembly in a support structure, which consists of an upper and lower flange, each made up of four electrically insulated machined stainless steel castings, and 12 tie rods preloading the complete assembly in the vertical direction. The upper flange is equipped with four radial restraining jacks and the lower flange is equipped with four sets of studs and shear keys to withstand the net vertical and lateral electromagnetic forces. The PFCI is equipped with inductive heaters, voltage taps, temperature transducers, strain gauges and other instrumentation as diagnostics to monitor the performance. The current status of the manufacture is that the coil has passed the final acceptance tests and it is in the support structure assembly stage.

  6. Second Generation Coil Design of the Nb3Sn low-beta Quadrupole for the High Luminosity LHC

    CERN Document Server

    Izquierdo Bermudez, S; Ballarino, A; Cavanna, E; Bossert, R; Cheng, D; Dietderich, D; Ferracin, P; Ghosh, A; Hagen,P; Holik, E; Perez, J C; Rochepault, E; Schmalzle, J; Todesco, E; Yu, M

    2016-01-01

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with a fine tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this paper we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.

  7. Design and optimization of a 3-coil resonance-based wireless power transfer system for biomedical implants

    KAUST Repository

    Yi, Ying

    2014-09-01

    This paper presents a resonance-based wireless power transfer system using a single layer of inductor coil windings, in a pancake configuration, in order to obtain a compact system for implantable electronic applications. We theoretically analyzed the system and characterized it by measuring its inductance, self-resonant frequency, and quality factor Q. In our resonance-based wireless power transfer prototype, we proposed a 3-coil system, using two 15-mm radius implantable coils, with a resonance frequency of 6.76MHz. This system can effectively transfer power for a distance of up to 50mm. Moreover, our proposed 3-coil system can achieve a high Q-factor and has a comparable power transfer efficiency (PTE) to previously reported works about 3-coil and 4-coil systems. The experimental PTE can achieve 82.4% at a separation distance of 20mm and more than 10% PTE at a distance of 40mm.

  8. Status report on the 12T split coil test facility SULTAN

    International Nuclear Information System (INIS)

    Blau, B.; Aebli, E.; Jakob, B.; Pasztor, G.; Vecsey, G.; della Corte, A.; Pasotti, G.; Sacchetti, N.; Spadoni, M.

    1992-01-01

    The third phase of upgrading of the superconductor test facility SULTAN into a split coil system (SULTAN III) is in progress. SULTAN III a join project of ENEA (Italy) and PSI (Switzerland) consists of two coil packages, each containing three concentrically mounted superconducting solenoids. Together they will produce a field of nearly 12T between the two coil packages, inside a solenoid bore of 58 cm. The outermost 6T coils have NbTi conductors, whereas the inner 9T and 12T coils are made of A-15 cables. All Nb 3 Sn coils are manufactured by the react-and-wind technique. The split coil arrangement, in connection with a sophisticated sample insert containing a 50 kA superconducting transformer, will allow testing of short samples of high current carrying superconductors, e.g. for fusion applications. The sample insert was designed to allow changing the samples within a few hours without warming up the whole magnet system. This paper deals with the present status and potential of the Split Coil Test Facility SULTAN III

  9. Transcatheter coil occluder for closure of ventricular septal defect (a report of 4 cases)

    International Nuclear Information System (INIS)

    Gao Wei; Zhou Aiqing; Yu Zhiqing; Li Fen; Zhong Yumin; Zhang Yuqi; Huang Meirong; Sun Kun

    2005-01-01

    Objective: To explore the indication, methodology and complication of transcatheter coil closure of ventricular septal defect (VSD) in children. Methods: Transcatheter closure of perimembranous VSD with coils was performed in 4 cases from 2003 to 2005. The Duct-Occlude (pfm) and detachable coil (Cook) were chosen for embolization depending on the results of the left ventricular angiogram. The coil size was generally about 1-4 mm larger than the diameter of VSD. Follow up was carried out with echocardiography, ultrasound and clinical examination. Results: The defect diameters of the four cases were 2.0 mm, 2.7 mm, 2.5 mm and 1.5 mm respectively. The Duct-Occlude were successfully implanted in 3 cases of perimembranous VSD with the same type coil (OD[mm]7-3-6, windings 5-3-4) for each. One detachable coil (Cook) (5 x 5) was implanted in the remaining case. All cases had trivial residual shunt immediately after implantation which disappeared 24 hours later. Follow-up for 2 months to one year showed no coil displacement and secondary bacterial arteritis. No tricuspid and aortic regurgitation, no emboli, no endocarditis, and no arrhythmia were found. Conclusions: Coil closure of some small VSD with membranate part pseudo-ventricular aneurysm has good efficacy with the advantages of simple operation, less metal content and mini-invasion also applicable for infants. (authors)

  10. A novel electric design for electromagnetic stimulation--the Slinky coil.

    Science.gov (United States)

    Ren, C; Tarjan, P P; Popović, D B

    1995-09-01

    A novel coil design for inductive electromagnetic stimulation of neural cells has been simulated and experimentally tested. This coil improves the focal effect of a magnetic stimulator, and it reduces its inductance, hence the efficiency of the system is improved. The basic structure of the device is derived from the popular "Slinky" toy. The actual device is formed by winding different numbers of loops forming a helical coil on a half torus. The loops are bunched at the axis of the torus. The coil, due to its geometry, generates a unique distribution of eddy currents in nearby tissues which is favorable compared to a solenoid type stimulator. This renders the Slinky coil more selective than conventional coils used for magnetic stimulation. The distribution of eddy currents was analyzed using Matlab, following Faraday's Law of Induction. Improved focality permits the current through the coil to be reduced for the same effect. In addition, the reduced inductance of the Slinky coil decreases the power requirement; thus, the improved efficiency of the system may allow the generation of bursts of pulses, and expand the utilization of the system to possible functional activation of certain neuro-muscular structures when peripheral nerves are stimulated.

  11. A polygonal double-layer coil design for high-efficiency wireless power transfer

    Science.gov (United States)

    Mao, Shitong; Wang, Hao; Mao, Zhi-Hong; Sun, Mingui

    2018-05-01

    In this work, we present a novel coil structure for the design of Wireless Power Transfer (WPT) systems via magnetic resonant coupling. The new coil consists of two layers of flat polygonal windings in square, pentagonal and hexagonal shapes. The double-layer coil can be conveniently fabricated using the print circuit broad (PCB) technology. In our design, we include an angle between the two layers which can be adjusted to change the area of inter-layer overlap. This unique structure is thoroughly investigated with respect to the quality factor Q and the power transfer efficiency (PTE) using the finite element method (FEM). An equivalent circuit is derived and used to explain the properties of the angularly shifted double-layer coil theoretically. Comparative experiments are conducted from which the performance of the new coil is evaluated quantitatively. Our results have shown that an increased shift angle improves the Q-factor, and the optimal PTE is achieved when the angle reaches the maximum. When compared to the pentagonal and hexagonal coils, the square coil achieves the highest PTE due to its lowest parasitic capacitive effects. In summary, our new coil design improves the performance of WPT systems and allows a formal design procedure for optimization in a given application.

  12. Radiation induced currents in MRI RF coils: application to linac/MRI integration

    Science.gov (United States)

    Burke, B.; Fallone, B. G.; Rathee, S.

    2010-02-01

    The integration of medical linear accelerators (linac) with magnetic resonance imaging (MRI) systems is advancing the current state of image-guided radiotherapy. The MRI in these integrated units will provide real-time, accurate tumor locations for radiotherapy treatment, thus decreasing geometric margins around tumors and reducing normal tissue damage. In the real-time operation of these integrated systems, the radiofrequency (RF) coils of MRI will be irradiated with radiation pulses from the linac. The effect of pulsed radiation on MRI radio frequency (RF) coils is not known and must be studied. The instantaneous radiation induced current (RIC) in two different MRI RF coils were measured and presented. The frequency spectra of the induced currents were calculated. Some basic characterization of the RIC was also done: isolation of the RF coil component responsible for RIC, dependence of RIC on dose rate, and effect of wax buildup placed on coil on RIC. Both the time and frequency characteristics of the RIC were seen to vary with the MRI RF coil used. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence on dose rate was seen. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. This study shows a measurable RIC present in MRI RF coils. This unwanted current could be possibly detrimental to the signal to noise ratio in MRI and produce image artifacts.

  13. Single-molecule observation of helix staggering, sliding, and coiled coil misfolding

    Science.gov (United States)

    Xi, Zhiqun; Gao, Ying; Sirinakis, George; Guo, Honglian; Zhang, Yongli

    2012-01-01

    The biological functions of coiled coils generally depend on efficient folding and perfect pairing of their α-helices. Dynamic changes in the helical registry that lead to staggered helices have only been proposed for a few special systems and not found in generic coiled coils. Here, we report our observations of multiple staggered helical structures of two canonical coiled coils. The partially folded structures are formed predominantly by coiled coil misfolding and occasionally by helix sliding. Using high-resolution optical tweezers, we characterized their energies and transition kinetics at a single-molecule level. The staggered states occur less than 2% of the time and about 0.1% of the time at zero force. We conclude that dynamic changes in helical registry may be a general property of coiled coils. Our findings should have broad and unique implications in functions and dysfunctions of proteins containing coiled coils. PMID:22451899

  14. Designed Coiled Coils Promote Folding of a Recombinant Bacterial Collagen*

    Science.gov (United States)

    Yoshizumi, Ayumi; Fletcher, Jordan M.; Yu, Zhuoxin; Persikov, Anton V.; Bartlett, Gail J.; Boyle, Aimee L.; Vincent, Thomas L.; Woolfson, Derek N.; Brodsky, Barbara

    2011-01-01

    Collagen triple helices fold slowly and inefficiently, often requiring adjacent globular domains to assist this process. In the Streptococcus pyogenes collagen-like protein Scl2, a V domain predicted to be largely α-helical, occurs N-terminal to the collagen triple helix (CL). Here, we replace this natural trimerization domain with a de novo designed, hyperstable, parallel, three-stranded, α-helical coiled coil (CC), either at the N terminus (CC-CL) or the C terminus (CL-CC) of the collagen domain. CD spectra of the constructs are consistent with additivity of independently and fully folded CC and CL domains, and the proteins retain their distinctive thermal stabilities, CL at ∼37 °C and CC at >90 °C. Heating the hybrid proteins to 50 °C unfolds CL, leaving CC intact, and upon cooling, the rate of CL refolding is somewhat faster for CL-CC than for CC-CL. A construct with coiled coils on both ends, CC-CL-CC, retains the ∼37 °C thermal stability for CL but shows less triple helix at low temperature and less denaturation at 50 °C. Most strikingly however, in CC-CL-CC, the CL refolds slower than in either CC-CL or CL-CC by almost two orders of magnitude. We propose that a single CC promotes folding of the CL domain via nucleation and in-register growth from one end, whereas initiation and growth from both ends in CC-CL-CC results in mismatched registers that frustrate folding. Bioinformatics analysis of natural collagens lends support to this because, where present, there is generally only one coiled-coil domain close to the triple helix, and it is nearly always N-terminal to the collagen repeat. PMID:21454493

  15. Computational analysis of residue contributions to coiled-coil topology

    Science.gov (United States)

    Ramos, Jorge; Lazaridis, Themis

    2011-01-01

    A variety of features are thought to contribute to the oligomeric and topological specificity of coiled coils. In previous work, we examined the determinants of oligomeric state. Here, we examine the energetic basis for the tendency of six coiled-coil peptides to align their α-helices in antiparallel orientation using molecular dynamics simulations with implicit solvation (EEF1.1). We also examine the effect of mutations known to disrupt the topology of these peptides. In agreement with experiment, ARG or LYS at a or d positions were found to stabilize the antiparallel configuration. The modeling suggests that this is not due to a–a′ or d–d′ repulsions but due to interactions with e′ and g′ residues. TRP at core positions also favors the antiparallel configuration. Residues that disfavor parallel dimers, such as ILE at d, are better tolerated in, and thus favor the antiparallel configuration. Salt bridge networks were found to be more stabilizing in the antiparallel configuration for geometric reasons: antiparallel helices point amino acid side chains in opposite directions. However, the structure with the largest number of salt bridges was not always the most stable, due to desolvation and configurational entropy contributions. In tetramers, the extent of stabilization of the antiparallel topology by core residues is influenced by the e′ residue on a neighboring helix. Residues at b and c positions in some cases also contribute to stabilization of antiparallel tetramers. This work provides useful rules toward the goal of designing coiled coils with a well-defined and predictable three-dimensional structure. PMID:21858887

  16. Design of a 28 MW pulse facility for testing superconducting coils to several hundred megajoules capacity

    International Nuclear Information System (INIS)

    Vogel, H.F.

    1980-01-01

    Railway traction motors are available in unit sizes convenient for installation and series-parallel grouping. They are rugged. Industry builds and refurbishes them with good economy and in quantities replenishing the rolling stock. We find them well suited for reversing the current in a superconducting winding. We focus on a pulsed energy of 20 to 100 MJ, discussing our analysis and facility planning. Limitations are imposed by the following maximum numbers tolerated by the motor - pulsed current of 3.0 to 3.5 kA, current change of 40 kA/s, and pulsed voltage of 1.8 kV. Hence, the number of machines needed in parallel follows from the coil current and its rate of change. The number in series is determined by the voltage. The power transfer is limited by the torsional strength of the motor shaft to a value affected by the flywheel mass

  17. Toroidal field coil torque structure

    International Nuclear Information System (INIS)

    Gaines, A.L.

    1983-01-01

    A torque structure is disclosed particularly suitable for utilization in a power reactor of the Tokamak-type, and operable therein for purposes of providing support for the toroidal field (TF) coils that comprise one of the major operating components of such a Tokamak power reactor. The subject torque structure takes the form of a frame structure that is operable to enable torque loads acting on the TF coils to be equilibrated as close to the area of force application as feasible. The aforesaid torque structure includes an intercoil structure composed of spacer wedges that are interposed between each adjacent pair of TF coils. The spacer wedges, in turn, consist of bearing plates positioned between the TF coils so as to be in contacting relation therewith and a number of cross plates that are cooperatively associated with the bearing plates so as to form therewith a rigid assembly. The intercoil structure is affixed to a segmented, membrane shell that surrounds, encloses and supports the TF coil frames. Access is had to the interior of the shell through an opening formed for this purpose in a reinforced portion of the shell. Eddy current losses are minimized by insulating the joints formed at the juncture of adjoining segments of the shell

  18. Update on High-Temperature Coils for Electromagnets

    Science.gov (United States)

    Kascak, Albert F.; Montague, Gerald T.; Palazzolo, Alan; Preuss, Jason; Carter, Bart; Tucker, Randall; Hunt, Andrew

    2005-01-01

    A report revisits the subject matter of "High-Temperature Coils for Electromagnets" (LEW-17164), NASA Tech Briefs, Vol. 26, No. 8, (August 2002) page 38. To recapitulate: Wires have been developed for use in electromagnets that operate at high temperatures. The starting material for a wire of this type can be either a nickel-clad, ceramic-insulated copper wire or a bare silver wire. The wire is covered by electrical-insulation material that is intended to withstand operating temperatures in the range from 800 to 1,300 F (.430 to .700 C): The starting wire is either primarily wrapped with S-glass as an insulating material or else covered with another insulating material wrapped in S-glass prior to the winding process. A ceramic binding agent is applied as a slurry during the winding process to provide further insulating capability. The turns are pre-bent during winding to prevent damage to the insulation. The coil is then heated to convert the binder into ceramic. The instant report mostly reiterates the prior information and presents some additional information on the application of the ceramic binding agent and the incorporation of high-temperature wire into the windings.

  19. Superconducting toroidal field coil current densities for the TFCX

    International Nuclear Information System (INIS)

    Kalsi, S.S.; Hooper, R.J.

    1985-04-01

    A major goal of the Tokamak Fusion Core Experiment (TFCX) study was to minimize the size of the device and achieve lowest cost. Two key factors influencing the size of the device employing superconducting magnets are toroidal field (TF) winding current density and its nuclear heat load withstand capability. Lower winding current density requires larger radial build of the winding pack. Likewise, lower allowable nuclear heating in the winding requires larger shield thickness between the plasma and coil. In order to achieve a low-cost device, it is essential to maximize the winding's current density and nuclear heating withhstand capability. To meet the above objective, the TFCX design specification adopted as goals a nominal winding current density of 3500 A/cm 2 with 10-T peak field at the winding and peak nuclear heat load limits of 1 MW/cm 3 for the nominal design and 50 MW/cm 3 for an advanced design. This study developed justification for these current density and nuclear heat load limits

  20. Magnetization of the joint-free high temperature superconductor (RE)Ba2Cu3Ox coil by field cooling

    Science.gov (United States)

    Zheng, Yali; Wang, Yawei; Li, Jianwei; Jin, Zhijian

    2017-09-01

    Joint-free (RE)Ba2Cu3Ox (REBCO) coil based on `wind-and-flip' technique has been developed to generate a persistent magnetic field without power supply. This paper is to study the magnetization characteristics of the joint-free REBCO coil by field cooling, in order to trap higher field. A joint-free pancake coil is wound by REBCO tapes and the field cooling magnetization test is performed on it. An approximate numerical model based on H-formulation is built for this coil to analyze its magnetization behavior, which is validated by the experimental results Analysis show that a persistent direct current is induced in the coil during the field cooling operation, which generates the trapped field. The induced current of the joint-free coil shows an intrinsic non-uniform distribution among turns. Increasing the magnetization field and critical current of REBCO conductors can considerably increase the trapped field. But the trapping factor (the rate of trapped field to background magnetization field) reaches a maximum value (60 % for the test coil). This maximum value is an intrinsic characteristics for a fabricated coil, which only depends on the coil's geometry structure. With a same usage of REBCO tapes, the trapping factor can be improved significantly by optimizing the coil structure to multiple pancakes, and it can approach 100 %.

  1. Self-assembled artificial viral capsids bearing coiled-coils at the surface.

    Science.gov (United States)

    Fujita, Seiya; Matsuura, Kazunori

    2017-06-14

    In order to construct artificial viral capsids bearing complementary dimeric coiled-coils on the surface, a β-annulus peptide bearing a coiled-coil forming sequence at the C-terminus (β-annulus-coiled-coil-B) was synthesized by a native chemical ligation of a β-annulus-SBn peptide with a Cys-containing coiled-coil-B peptide. Dynamic light scattering (DLS) measurements and transmission electron microscopy (TEM) images revealed that the β-annulus-coiled-coil-B peptide self-assembled into spherical structures of about 50 nm in 10 mM Tris-HCl buffer. Circular dichroism (CD) spectra indicated the formation of the complementary coiled-coil structure on the spherical assemblies. Addition of 0.25 equivalent of the complementary coiled-coil-A peptide to the β-annulus-coiled-coil-B peptide showed the formation of spherical assemblies of 46 ± 14 nm with grains of 5 nm at the surface, whereas addition of 1 equivalent of the complementary coiled-coil-A peptide generated fibrous assemblies.

  2. Coiled-coil domains enhance the membrane association of Salmonella type III effectors.

    Science.gov (United States)

    Knodler, Leigh A; Ibarra, J Antonio; Pérez-Rueda, Ernesto; Yip, Calvin K; Steele-Mortimer, Olivia

    2011-10-01

    Coiled-coil domains in eukaryotic and prokaryotic proteins contribute to diverse structural and regulatory functions. Here we have used in silico analysis to predict which proteins in the proteome of the enteric pathogen, Salmonella enterica serovar Typhimurium, harbour coiled-coil domains. We found that coiled-coil domains are especially prevalent in virulence-associated proteins, including type III effectors. Using SopB as a model coiled-coil domain type III effector, we have investigated the role of this motif in various aspects of effector function including chaperone binding, secretion and translocation, protein stability, localization and biological activity. Compared with wild-type SopB, SopB coiled-coil mutants were unstable, both inside bacteria and after translocation into host cells. In addition, the putative coiled-coil domain was required for the efficient membrane association of SopB in host cells. Since many other Salmonella effectors were predicted to contain coiled-coil domains, we also investigated the role of this motif in their intracellular targeting in mammalian cells. Mutation of the predicted coiled-coil domains in PipB2, SseJ and SopD2 also eliminated their membrane localization in mammalian cells. These findings suggest that coiled-coil domains represent a common membrane-targeting determinant for Salmonella type III effectors. Published 2011. This article is a US Government work and is in the public domain in the USA.

  3. The structure of the GemC1 coiled coil and its interaction with the Geminin family of coiled-coil proteins

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, Christophe; Fish, Alexander [The Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Pefani, Dafni-Eleftheria; Taraviras, Stavros; Lygerou, Zoi [University of Patras, 26505 Rio, Patras (Greece); Perrakis, Anastassis, E-mail: a.perrakis@nki.nl [The Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands)

    2015-10-31

    The GemC1 coiled-coil structure has subtle differences compared with its homologues Geminin and Idas. Co-expression experiments in cells and biophysical stability analysis of the Geminin-family coiled coils suggest that the GemC1 coiled coil alone is unstable. GemC1, together with Idas and Geminin, an important regulator of DNA-replication licensing and differentiation decisions, constitute a superfamily sharing a homologous central coiled-coil domain. To better understand this family of proteins, the crystal structure of a GemC1 coiled-coil domain variant engineered for better solubility was determined to 2.2 Å resolution. GemC1 shows a less typical coiled coil compared with the Geminin homodimer and the Geminin–Idas heterodimer structures. It is also shown that both in vitro and in cells GemC1 interacts with Geminin through its coiled-coil domain, forming a heterodimer that is more stable that the GemC1 homodimer. Comparative analysis of the thermal stability of all of the possible superfamily complexes, using circular dichroism to follow the unfolding of the entire helix of the coiled coil, or intrinsic tryptophan fluorescence of a unique conserved N-terminal tryptophan, shows that the unfolding of the coiled coil is likely to take place from the C-terminus towards the N-terminus. It is also shown that homodimers show a single-state unfolding, while heterodimers show a two-state unfolding, suggesting that the dimer first falls apart and the helices then unfold according to the stability of each protein. The findings argue that Geminin-family members form homodimers and heterodimers between them, and this ability is likely to be important for modulating their function in cycling and differentiating cells.

  4. Status report of the CMS superconducting coil project

    CERN Document Server

    Campi, D; Hervé, A; Horváth, I L; Kircher, F

    2001-01-01

    The CMS superconducting coil is designed for one of the two large experiments of LHC at CERN. This coil 12.5 m long, 6 m diameter and 2.7 GJ stored energy is a common project of the CMS Collaboration. It is a four-layer coil, equipped with a self-supporting conductor capable of carrying 20 kA to reach the maximum potential field of 4 T. It has been designed with a considerable contribution from CEA- Saclay for the engineering, ETH-Zurich for the conductor, INFN-Genova for the winding and CERN for the general coordination and construction of the ancillaries. The project entered the construction phase one year ago. The civil engineering is well advanced and ready to accept part of the yoke components already built. The coil itself has finished the pre-industrialization phase and the construction is beginning in industry. Most of the important contracts have been awarded and the foreseen schedule is now based on contractual engagements. A quick overview of the features of the project as well as a status report o...

  5. Starting the production of the CEA JT-60SA TF coils at Alstom

    Energy Technology Data Exchange (ETDEWEB)

    Decool, P., E-mail: patrick.decool@cea.fr [CEA, IRFM, F-13108 St-Paul-Lez-Durance Cedex (France); Cloez, H.; Gros, G.; Jiolat, G.; Marechal, J.L.; Nicollet, S.; Torre, A.; Verger, J.M. [CEA, IRFM, F-13108 St-Paul-Lez-Durance Cedex (France); Nusbaum, M.; Billotte, G.; Crepel, B.; Bourquard, A.; Schweitzer, M. [Alstom Power Systems STTG Magnets, 90018 Belfort (France); Davis, S.; Phillips, G. [Fusion for Energy, Boltzmannstr 2, 85748 Garching (Germany)

    2015-10-15

    Highlights: • We describe the status of the JT-60SA TF coils manufacture at Alstom. • The manufacturing workflow and related tooling are described. • Completion of qualification activities has allowed to start the coils production. • Production of the first winding up to its impregnation is described. • Winding of following coils is started. - Abstract: Within the framework of the Broader Approach, the French voluntary contributor represented by CEA awarded a contract for the production of 9 toroidal field coils for the JT-60SA project to Alstom, Belfort, France in mid-2011. A first preparatory phase was led to establish the team, produce the manufacture drawings, define the manufacturing process, procure the required tooling and prepare the quality documentation. In parallel, a qualification phase on the critical major processes has proved Alstom's ability to master the processes and reach the requirements. After reviewing of the qualification results and modification of the processes and tooling to overcome the encountered difficulties, a Production Readiness Review has authorized Alstom to start the production winding. A prototype double pancake was wound as the first of series. In addition to complying with the pancake width all around the D shape, the straightness of the centreline in the critical straight leg part was correct. The production of the successive double pancakes to constitute the first winding pack was then completed and the joints and terminals were manufactured. The paper describes the completion of the last qualifications and the status of the winding production.

  6. Large coil program support structure conceptual design

    International Nuclear Information System (INIS)

    Litherland, P.S.

    1977-01-01

    The purpose of the Large Coil Program (LCP) is to perform tests on both pool boiling and force cooled superconducting toroidal field coils. The tests will attempt to approximate conditions anticipated in an ignition tokamak. The test requirements resulted in a coil support design which accommodates up to six (6) test coils and is mounted to a structure capable of resisting coil interactions. The steps leading to the present LCP coil support structure design, details on selected structural components, and the basic assembly sequence are discussed

  7. Structural and biochemical characterizations of an intramolecular tandem coiled coil protein.

    Science.gov (United States)

    Shin, Donghyuk; Kim, Gwanho; Kim, Gyuhee; Zheng, Xu; Kim, Yang-Gyun; Lee, Sangho

    2014-12-12

    Coiled coil has served as an excellent model system for studying protein folding and developing protein-based biomaterials. Most designed coiled coils function as oligomers, namely intermolecular coiled coils. However, less is known about structural and biochemical behavior of intramolecular coiled coils where coiled coil domains are covalently linked in one polypeptide. Here we prepare a protein which harbors three coiled coil domains with two short linkers, termed intramolecular tandem coiled coil (ITCC) and characterize its structural and biochemical behavior in solution. ITCC consists of three coiled coil domains whose sequences are derived from Coil-Ser and its domain swapped dimer. Modifications include positioning E (Glu) residue at "e" and K (Lys) at "g" positions throughout heptad repeats to enhance ionic interaction among its constituent coiled coil domains. Molecular modeling of ITCC suggests a compact triple helical bundle structure with the second and the third coiled coil domains forming a canonical coiled coil. ITCC exists as a mixture of monomeric and dimeric species in solution. Small-angle X-ray scattering reveals ellipsoidal molecular envelopes for both dimeric and monomeric ITCC in solution. The theoretically modeled structures of ITCC dock well into the envelopes of both species. Higher ionic strength shifts the equilibrium into monomer with apparently more compact structure while secondary structure remains unchanged. Taken together, our results suggest that our designed ITCC is predominantly monomeric structure through the enhanced ionic interactions, and its conformation is affected by the concentration of ionic species in the buffer. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. On modular stellarator coils of the W VII-AS type with reactor dimensions

    International Nuclear Information System (INIS)

    Hermeyer, E.; Kisslinger, J.; Rau, F.; Wobig, H.

    1985-01-01

    Modular Stellarator coil systems of the W VII-AS type with reactor dimensions are investigated. They comprise 5 field periods with 6 to 18 coils within each. Two groups of configurations are compared. The first group is characterized by the major torus radius of R 0 = 25.5 m and a distance between plasma and coils of ccdcc 1.8 m. The field on plasma axis amounts to B 3 = 5.3 T. In the second group the geometric dimensions are decreased. The major torus radius amounts to R 3 = 15.2 m, and a distance of about 1.2 m is chosen between plasma and coils. The field on plasma axis is enlarged to B 3 = 7 T. The total stored magnetic energy of the coil systems and the maximum magnetic flux density at the coils are calculated. Furthermore, the magnetic forces and mechanical stresses are evaluated, and two different support concepts for the coils are investigated: A single coil support scheme (outer and lateral support elements plus elastic padding), as well as a novel scheme of mutual coil support

  9. Large Coil Program magnetic system design study

    International Nuclear Information System (INIS)

    Moses, S.D.; Johnson, N.E.

    1977-01-01

    The primary objective of the Large Coil Program (LCP) is to demonstrate the reliable operation of large superconducting coils to provide a basis for the design principles, materials, and fabrication techniques proposed for the toroidal magnets for the THE NEXT STEP (TNS) and other future tokamak devices. This paper documents a design study of the Large Coil Test Facility (LCTF) in which the structural response of the Toroidal Field (TF) Coils and the supporting structure was evaluated under simulated reactor conditions. The LCP test facility structural system consists of six TF Coils, twelve coil-to-coil torsional restraining beams (torque rings), a central bucking post with base, and a Pulse Coil system. The NASTRAN Finite Element Structural Analysis computer Code was utilized to determine the distribution of deflections, forces, and stresses for each of the TF Coils, torque rings, and the central bucking post. Eleven load conditions were selected to represent probable test operations. Pulse Coils suspended in the bore of the test coil were energized to simulate the pulsed field environment characteristic of the TNS reactor system. The TORMAC Computer Code was utilized to develop the magnetic forces in the TF Coils for each of the eleven loading conditions examined, with or without the Pulse Coils energized. The TORMAC computer program output forces were used directly as input load conditions for the NASTRAN analyses. Results are presented which demonstrate the reliability of the LCTF under simulated reactor operating conditions

  10. Wind turbines, is it just wind?

    International Nuclear Information System (INIS)

    Boiteux, M.

    2012-01-01

    The author first outlines that wind energy is not only random, but almost absent in extreme situations when it would be needed (for example and notably, very cold weather without wind). He suggests the association of a gas turbine to each wind turbine, so that the gas turbine will replace non operating wind turbines. He notices that wind turbines are not proximity energy as they were said to be, and that profitability in fact requires tens of grouped giant wind turbines. He also outlines the high cost of construction of grids for the connection of these wind turbines. Thus, he states that wind energy is far from being profitable in the present conditions of electricity tariffs in France

  11. Construction of Specialty Guide Field Coils Using an Industrial Robotic Arm

    Science.gov (United States)

    Berry, William; Crawford, Christopher; Fugal, Mario; Martin, Elise; Wagner, Daniel; Milburn, Robert

    2011-10-01

    Many contemporary nuclear physics experiments require precise control of the magnetic field within key regions of the experimental apparatus. The nEDM experiment, for instance, requires uniform guide fields (produced by guide field coils) to transport neutron spin polarization from the polarizer to the measurement cell. Guide field coils in general are subject to tight geometrical constraints, and must not produce any external fields which would affect the results of the experiment. In order to produce a satisfactory coil in light of these constraints, a systematic design technique is needed. We introduce the magnetic scalar potential technique, which calculates the exact coil windings required on a specified boundary to produce any desired field distribution inside that satisfies Maxwell's equations. Realizing the designs produced by this technique introduces an additional difficulty: winding many turns according to the exact calculated paths. This is addressed by ``printing'' our coils onto a copper-plated G10 form using a calibrated robot arm and spindle, resulting in a 3-d printed circuit board. To correct for deviations in the actual shape of the form, we use a laser displacement sensor to capture the actual geometry as input into the calculation of the windings. Supported in part by NSF grant PHY-0855584.

  12. Open-coil retraction spring.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2011-01-01

    Sliding mechanic has become a popular method for space closure with developments in preadjusted edgewise appliance. Furthermore, various space closing auxiliaries have been developed and evaluated extensively for their clinical efficiency. Their effectiveness enhanced with optimum force magnitude and low-load deflection rate (LDR)/force decay. With the advent of NiTi springs in orthodontics, LDRs have been markedly reduced. For use of NiTi, clinician has to depend upon prefabricated closed coil springs. "Open Coil Retraction Spring (OCRS)" is developed utilizing NiTi open-coil spring for orthodontic space closure. This paper describes fabrication and clinical application of OCRS which have number of advantages. It sustains low LDR with optimum force magnitude. Its design is adjustable for desired length and force level. It is fail-safe for both activation and deactivation (i.e., it cannot be over activated, and decompression limit of open coil is also controlled by the operator, resp.). A possibility to offset the OCRS away from mucosa helps to reduce its soft-tissue impingement.

  13. Open-Coil Retraction Spring

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available Sliding mechanic has become a popular method for space closure with developments in preadjusted edgewise appliance. Furthermore, various space closing auxiliaries have been developed and evaluated extensively for their clinical efficiency. Their effectiveness enhanced with optimum force magnitude and low-load deflection rate (LDR/force decay. With the advent of NiTi springs in orthodontics, LDRs have been markedly reduced. For use of NiTi, clinician has to depend upon prefabricated closed coil springs. “Open Coil Retraction Spring (OCRS” is developed utilizing NiTi open-coil spring for orthodontic space closure. This paper describes fabrication and clinical application of OCRS which have number of advantages. It sustains low LDR with optimum force magnitude. Its design is adjustable for desired length and force level. It is fail-safe for both activation and deactivation (i.e., it cannot be over activated, and decompression limit of open coil is also controlled by the operator, resp.. A possibility to offset the OCRS away from mucosa helps to reduce its soft-tissue impingement.

  14. Finite element coiled cochlea model

    Science.gov (United States)

    Isailovic, Velibor; Nikolic, Milica; Milosevic, Zarko; Saveljic, Igor; Nikolic, Dalibor; Radovic, Milos; Filipović, Nenad

    2015-12-01

    Cochlea is important part of the hearing system, and thanks to special structure converts external sound waves into neural impulses which go to the brain. Shape of the cochlea is like snail, so geometry of the cochlea model is complex. The simplified cochlea coiled model was developed using finite element method inside SIFEM FP7 project. Software application is created on the way that user can prescribe set of the parameters for spiral cochlea, as well as material properties and boundary conditions to the model. Several mathematical models were tested. The acoustic wave equation for describing fluid in the cochlea chambers - scala vestibuli and scala timpani, and Newtonian dynamics for describing vibrations of the basilar membrane are used. The mechanical behavior of the coiled cochlea was analyzed and the third chamber, scala media, was not modeled because it does not have a significant impact on the mechanical vibrations of the basilar membrane. The obtained results are in good agreement with experimental measurements. Future work is needed for more realistic geometry model. Coiled model of the cochlea was created and results are compared with initial simplified coiled model of the cochlea.

  15. Wedding ring shaped excitation coil

    Science.gov (United States)

    MacLennan, Donald A.; Tsai, Peter

    2001-01-01

    A high frequency inductively coupled electrodeless lamp includes an excitation coil with an effective electrical length which is less than one half wavelength of a driving frequency applied thereto, preferably much less. The driving frequency may be greater than 100 MHz and is preferably as high as 915 MHz. Preferably, the excitation coil is configured as a non-helical, semi-cylindrical conductive surface having less than one turn, in the general shape of a wedding ring. At high frequencies, the current in the coil forms two loops which are spaced apart and parallel to each other. Configured appropriately, the coil approximates a Helmholtz configuration. The lamp preferably utilizes an bulb encased in a reflective ceramic cup with a pre-formed aperture defined therethrough. The ceramic cup may include structural features to aid in alignment and/or a flanged face to aid in thermal management. The lamp head is preferably an integrated lamp head comprising a metal matrix composite surrounding an insulating ceramic with the excitation integrally formed on the ceramic. A novel solid-state oscillator preferably provides RF power to the lamp. The oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency.

  16. PDX toroidal field coils stress analysis

    International Nuclear Information System (INIS)

    Nikodem, Z.D.; Smith, R.A.

    1975-01-01

    A method used in the stress analysis of the PDX toroidal field coil is developed. A multilayer coil design of arbitrary dimensions in the shape of either a circle or an oval is considered. The analytical model of the coil and the supporting coil case with connections to the main support structure is analyzed using the finite element technique. The three dimensional magnetic fields and the non-uniform body forces which are a loading condition on a coil due to toroidal and poloidal fields are calculated. The method of analysis permits rapid and economic evaluations of design changes in coil geometry as well as in coil support structures. Some results pertinent to the design evolution and their comparison are discussed. The results of the detailed stress analysis of the final coil design due to toroidal field, poloidal field and temperature loads are presented

  17. Computational fluid dynamics (CFD using porous media modeling predicts recurrence after coiling of cerebral aneurysms.

    Directory of Open Access Journals (Sweden)

    Yasuyuki Umeda

    Full Text Available This study aimed to predict recurrence after coil embolization of unruptured cerebral aneurysms with computational fluid dynamics (CFD using porous media modeling (porous media CFD.A total of 37 unruptured cerebral aneurysms treated with coiling were analyzed using follow-up angiograms, simulated CFD prior to coiling (control CFD, and porous media CFD. Coiled aneurysms were classified into stable or recurrence groups according to follow-up angiogram findings. Morphological parameters, coil packing density, and hemodynamic variables were evaluated for their correlations with aneurysmal recurrence. We also calculated residual flow volumes (RFVs, a novel hemodynamic parameter used to quantify the residual aneurysm volume after simulated coiling, which has a mean fluid domain > 1.0 cm/s.Follow-up angiograms showed 24 aneurysms in the stable group and 13 in the recurrence group. Mann-Whitney U test demonstrated that maximum size, dome volume, neck width, neck area, and coil packing density were significantly different between the two groups (P < 0.05. Among the hemodynamic parameters, aneurysms in the recurrence group had significantly larger inflow and outflow areas in the control CFD and larger RFVs in the porous media CFD. Multivariate logistic regression analyses demonstrated that RFV was the only independently significant factor (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = 0.016.The study findings suggest that RFV collected under porous media modeling predicts the recurrence of coiled aneurysms.

  18. Design and modelling of a SMES coil

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Weijia; Campbell, A M; Coombs, T A, E-mail: wy215@cam.ac.u [EPEC Superconductivity group, Engineering Department, 9 JJ Thomson Avenue, Cambridge, CB3 0FA (United Kingdom)

    2010-06-01

    The design of a Superconducting Magnetic Energy Storage (SMES) coil wound by coated conductors has been presented. Based on an existing model for coated conductor pancake coils, this paper analysed the magnetic field and current density distribution of the coil at two different operation temperatures, 77K and 22K. A comparison table of the critical currents and AC losses at these two temperatures has been presented. Several steps to improve the transport current of the coil have been suggested as well.

  19. Bow-shaped toroidal field coils

    International Nuclear Information System (INIS)

    Bonanos, P.

    1981-05-01

    Design features of Bow-Shaped Toroidal Field Coils are described and compared with circular and D shaped coils. The results indicate that bow coils can produce higher field strengths, store more energy and be made demountable. The design offers the potential for the production of ultrahigh toroidal fields. Included are representative coil shapes and their engineering properties, a suggested structural design and an analysis of a specific case

  20. Nested Surface Coils for Multinuclear NMR

    OpenAIRE

    Magill, Arthur; Gruetter, Rolf

    2011-01-01

    This article introduces the design of surface coils for multinuclear applications. The relative sensitivities of several NMR-visible nuclei of biological interest are considered, and the motivations to operate an RF coil at multiple frequencies, both sequentially and simultaneously, are reviewed. The design of nested surface coils is then developed. Magnetic fields generated by planar loop and butterfly coils are first introduced. The benefits of quadrature design are briefly considered, and ...

  1. Change-actors in the U.S. electric energy system: The role of environmental groups in utility adoption and diffusion of wind power

    International Nuclear Information System (INIS)

    Doblinger, Claudia; Soppe, Birthe

    2013-01-01

    We study the contribution of environmental groups to new technology adoption and diffusion by dominant incumbents. Building on institutional and social movement theory, we develop a theoretical framework that sheds light on environmental groups as change-actors. We theorize that by approaching embedded key constituents with various strategic actions, environmental groups affect taken-for-granted beliefs, build legitimacy for renewable energy technologies, and convince skeptical constituents to support the new technology. We verify our theoretical framework with a case study of wind power development in Colorado. We find that environmentalists educate constituents on the benefits of the new technology, engage in activities leading to regulatory and legislative decisions for wind, while also providing direct assistance to the utility. As a result, utilities are both pressured and encouraged to adopt and diffuse wind power on a large-scale. This research directs attention to the role of environmental groups as change-actors and the legitimating effects of their actions. It highlights their part in creating a more favorable institutional environment for new technologies while directly influencing the incumbent's technology choice. This paper contributes to an understanding of bottom-up, actor-initiated changes in energy systems taking into account both the systemic technological infrastructure and the institutional context. - Highlights: • We study environmentalists′ impact on utility-scale renewable technology diffusion. • Incumbent-dominated systems hinder the diffusion of new technologies. • Environmental groups′ strategic actions increase legitimacy for new technologies. • Environmental groups′ legitimating actions affect incumbent′s technology choice. • Environmental groups create a favorable institutional context for new technologies

  2. Quench analysis of pancake wound REBCO coils with low resistance between turns

    International Nuclear Information System (INIS)

    Markiewicz, W Denis; Jaroszynski, Jan J; Abraimov, Dymtro V; Joyner, Rachel E; Khan, Amanatullah

    2016-01-01

    Quench in a pancake wound REBCO superconducting coil with low resistance (LR) between turns is examined by numerical analysis. In these calculations it is generally observed that once established, quench propagates rapidly in LR coils. Large transients are induced in the azimuthal solenoid current, allowed by the LR between turns, and become self-propagating. The transition from an initial state characterized by thermal diffusion to the dynamic inductive state of quench propagation is observed. The analysis is applied to the inner coil of a 30 T magnet where the quench performance is studied as a function of the value of resistance between turns. Rapid propagation of quench is seen in calculations for resistance between turns significantly greater than the resistance reported for no-insulation coils. The influence on quench of both steel co-wind and the amount of copper in the conductor is examined through calculation of the maximum temperature and the quench propagation velocity. (paper)

  3. Quench analysis of pancake wound REBCO coils with low resistance between turns

    Science.gov (United States)

    Markiewicz, W. Denis; Jaroszynski, Jan J.; Abraimov, Dymtro V.; Joyner, Rachel E.; Khan, Amanatullah

    2016-02-01

    Quench in a pancake wound REBCO superconducting coil with low resistance (LR) between turns is examined by numerical analysis. In these calculations it is generally observed that once established, quench propagates rapidly in LR coils. Large transients are induced in the azimuthal solenoid current, allowed by the LR between turns, and become self-propagating. The transition from an initial state characterized by thermal diffusion to the dynamic inductive state of quench propagation is observed. The analysis is applied to the inner coil of a 30 T magnet where the quench performance is studied as a function of the value of resistance between turns. Rapid propagation of quench is seen in calculations for resistance between turns significantly greater than the resistance reported for no-insulation coils. The influence on quench of both steel co-wind and the amount of copper in the conductor is examined through calculation of the maximum temperature and the quench propagation velocity.

  4. 3-Coil resonance-based wireless power transfer system for implantable electronic

    KAUST Repository

    Yi, Ying

    2013-05-01

    This paper presents a 3-coil resonance-based wireless power transfer (R-WPT) system using a single layer of inductor coil windings, in a pancake configuration, in order to obtain a compact system for implantable electronic applications. A theoretical analysis and experimental measurements in terms of quality factor Q and power transfer efficiency (PTE), was done. Our proposed 3-coil scheme can achieve a high PTE with a resonance frequency of 2.46 MHz over a transfer distance of up to 30 mm, by using two 15-mm radius implant coils. The achieved experimental PTE is more than 85%at a 5 mm separation distance, and about 50% PTE at a distance of 20 mm. © 2013 IEEE.

  5. Plasmodium vivax antigen discovery based on alpha-helical coiled coil protein motif

    DEFF Research Database (Denmark)

    Céspedes, Nora; Habel, Catherine; Lopez-Perez, Mary

    2014-01-01

    Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Pla...

  6. Are coiled-coils of dimeric kinesins unwound during their walking on microtubule?

    Science.gov (United States)

    Duan, Zhao-Wen; Xie, Ping; Li, Wei; Wang, Peng-Ye

    2012-01-01

    Dimeric kinesin motor proteins such as homodimeric kinesin-1, homodimeric Ncd and heterodimeric Kar3/Vik1are composed of two head domains which are connected together by a rod-shaped, coiled-coil stalk. Despite the extensive and intensive studies on structures, kinetics, dynamics and walking mechanism of the dimers, whether their coiled-coils are unwound or not during their walking on the microtubule is still an unclear issue. Here, we try to clarify this issue by using molecular dynamics simulations. Our simulation results showed that, for Ncd, a large change in potential of mean force is required to unwind the coiled-coil by only several pairs of residues. For both Ncd and kinesin-1, the force required to initiate the coiled-coil unwinding is larger than that required for unfolding of the single [Formula: see text]-helix that forms the coiled-coil or is larger than that required to unwind the DNA duplex, which is higher than the unbinding force of the kinesin head from the microtubule in strong microtubule-binding states. Based on these results and the comparison of the sequence between the coiled-coil of Kar3/Vik1 and those of Ncd and kinesin-1, it was deduced that the coiled-coil of the Kar3/Vik1 should also be very stable. Thus, we concluded that the coiled-coils of kinesin-1, Ncd and Kar3/Vik1 are almost impossible to unwind during their walking on the microtubule.

  7. The umbilical coiling index in normal pregnancy

    NARCIS (Netherlands)

    van Diik, C. C.; Franx, A.; de Laat, M. W. M.; Bruinse, H. W.; Visser, G. H. A.; Nikkels, P. G. J.

    2002-01-01

    To provide reference values for the umbilical coiling index in uncomplicated pregnancy. Umbilical cords were collected from livebom singleton infants born after uncomplicated pregnancies. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length in

  8. The umbilical coiling index in complicated pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; van Alderen, Elise D.; Franx, Arie; Visser, Gerard H. A.; Bots, Michiel L.; Nikkels, Peter G. J.

    2007-01-01

    To evaluate umbilical cord coiling in pregnancies with adverse outcome. Umbilical cords and hospital records of 565 consecutive cases with an indication for histological examination of the placenta were studied. The umbilical coiling index (UCI) was determined as the number of complete coils divided

  9. Development of SMART CRDM Coil Design

    International Nuclear Information System (INIS)

    Lee, Jae Seon; Kim, Tae Wan; Choi, Suhn; Park, Hee June

    2011-01-01

    A control rod drive mechanism (CRDM) is an electromagnetic device which drives a control rod assembly linearly to regulate reactivity of a nuclear core. Driving force is electromagnetic force generated from coils installed outside of a motor housing. The magnetic parts of a motor assembly installed inside of a motor housing are magnetized when a coil is activated, and adhere to each other to produce latching or driving force as a result. A coil assembly consists of a lifting coil, a movable latch coil and a stationary latch coil as shown in Fig. 1. The latch coils make a drive shaft engaged with or released from latches, and the lift coil makes a drive shaft and a control rod assembly move up or drop. A CRDM control system supplies controlled electric current to a specified coil in order, and then a control rod assembly moves up or down. The coil assembly for SMART CRDM has been developed based on the design concept of a coil assembly for control element drive mechanism (CEDM) of the OPR1000, and modified to satisfy dedicated design requirements for SMART reactor. Some of representative design requirements are the lifting capacity of 3200N which is greater, the lifting step of 15.875mm which is longer than that for CEDM, and one step driving instead of two step driving. Design process through an electromagnetic analysis for a lift coil is described herein as a representative example, and representative results of the analysis are presented

  10. Features of Traction Transformer Windings Utilised as Inductances

    Directory of Open Access Journals (Sweden)

    Jiri Danzer

    2004-01-01

    Full Text Available The paper analyses features of traction transformer desing. Secondary windings of the transformer are utilized as a choke of an locomotive input filter at DC supplying system. Different ways of connections of the secondary windings coils are compared, reachable inductances are determined and forces affecting the coils are computed. The analysis is performed by FEM method for differend locomotive operating modes including breakdown service.

  11. Manufacturing and test of 2G-HTS coils for rotating machines: Challenges, conductor requirements, realization

    International Nuclear Information System (INIS)

    Oomen, Marijn; Herkert, Werner; Bayer, Dietmar; Kummeth, Peter; Nick, Wolfgang; Arndt, Tabea

    2012-01-01

    We investigate the use of 2nd-generation High-Temperature Superconductors (2G-HTSs) in the rotors of electrical motors and generators. For these devices the conductor must be wound into robust impregnated coils, which are operated in vacuum at temperatures around 30 K, in strong magnetic fields of about 2T. Differences in thermal contraction between the coil former, conductor constituents, impregnation resin, bandage and heat-sink materials (assembled at room temperature) cause mechanical stresses at operating temperature. Rotating-machine operation adds Lorentz forces and challenging centripetal accelerations up to thousands of g. Second generation-HTS conductors withstand large tensile stresses in axial direction and compression in normal direction. However, shear stresses, axial compression, and tension normal to the conductor can cause degradation in superconducting properties. Such stresses can be mitigated by correct choice of materials, coil lay-out and manufacturing process. A certain stress level will remain, which the conductor must withstand. We have manufactured many impregnated round and race-track coils, using different 2G-HTS conductors, and tested them at temperatures from 25 K to 77 K. Degradation of the superconductor in early coils was traced to the mentioned differences in thermal contraction, and was completely avoided in coils produced later. We will discuss appropriate coil-winding techniques to assure robust and reliable superconductor performance.

  12. Room Temperature Magnetic Determination of the Current Center Line for the ITER TF Coils

    CERN Document Server

    Lerch, Philippe; Buzio, Marco; Negrazus, Marco; Baynham, Elwyn; Sanfilippo, Stephane; Foussat, Arnaud

    2014-01-01

    The ITER tokamak includes 18 superconducting D-shaped toroidal field (IT) coils. Unavoidable shape deformations as well as assembly errors will lead to field errors, which can be modeled with the knowledge of the current center line (CCL). Accurate survey during the entire manufacturing and assembly process, including transfer of survey points, is complex. In order to increase the level of confidence, a room temperature magnetic measurement of the CCL on assembled and closed winding packs is foreseen, prior to insertion into their cold case. In this contribution, we discuss the principle of the CCL determination and present a low frequency ac measurement system under development at PSI, within an ITER framework contract. The largest current allowed to flow in the TF coil at room temperature and the precision requirements for the determination of the CCL loci of the coil are hard boundaries. Eddy currents in the radial plates, the winding pack enclosures, and possibly from iron in the reinforced concrete floor...

  13. Modular assembly of a protein nanotriangle using orthogonally interacting coiled coils.

    Science.gov (United States)

    Park, Won Min; Bedewy, Mostafa; Berggren, Karl K; Keating, Amy E

    2017-09-05

    Synthetic protein assemblies that adopt programmed shapes would support many applications in nanotechnology. We used a rational design approach that exploits the modularity of orthogonally interacting coiled coils to create a self-assembled protein nanotriangle. Coiled coils have frequently been used to construct nanoassemblies and materials, but rarely with successful prior specification of the resulting structure. We designed a heterotrimer from three pairs of heterodimeric coiled coils that mediate specific interactions while avoiding undesired crosstalk. Non-associating pairs of coiled-coil units were strategically fused to generate three chains that were predicted to preferentially form the heterotrimer, and a rational annealing process led to the desired oligomer. Extensive biophysical characterization and modeling support the formation of a molecular triangle, which is a shape distinct from naturally occurring supramolecular nanostructures. Our approach can be extended to design more complex nanostructures using additional coiled-coil modules, other protein parts, or templated surfaces.

  14. The clear and dark sides of water: influence on the coiled coil folding domain.

    Science.gov (United States)

    Vajda, Tamás; Perczel, András

    2016-06-01

    The essential role of water in extra- and intracellular coiled coil structures of proteins is critically evaluated, and the different protein types incorporating coiled coil units are overviewed. The following subjects are discussed: i) influence of water on the formation and degradation of the coiled coil domain together with the stability of this conformer type; ii) the water's paradox iii) design of coiled coil motifs and iv) expert opinion and outlook is presented. The clear and dark sides refer to the positive and negative aspects of the water molecule, as it may enhance or inhibit a given folding event. This duplicity can be symbolized by the Roman 'Janus-face' which means that water may facilitate and stimulate coiled coil structure formation, however, it may contribute to the fatal processes of oligomerization and amyloidosis of the very same polypeptide chain.

  15. Wind power

    International Nuclear Information System (INIS)

    2006-06-01

    This road-map proposes by the Group Total aims to inform the public on the wind power. It presents the principles, the technology takes off, its applications and technology focus, the global market trends and the outlooks and Total commitments in the domain. (A.L.B.)

  16. Experiment study on an inductive superconducting fault current limiter using no-insulation coils

    Science.gov (United States)

    Qiu, D.; Li, Z. Y.; Gu, F.; Huang, Z.; Zhao, A.; Hu, D.; Wei, B. G.; Huang, H.; Hong, Z.; Ryu, K.; Jin, Z.

    2018-03-01

    No-insulation (NI) coil made of 2 G high temperature superconducting (HTS) tapes has been widely used in DC magnet due to its excellent performance of engineering current density, thermal stability and mechanical strength. However, there are few AC power device using NI coil at present. In this paper, the NI coil is firstly applied into inductive superconducting fault current limiter (iSFCL). A two-winding structure air-core iSFCL prototype was fabricated, composed of a primary copper winding and a secondary no-insulation winding using 2 G HTS coated conductors. Firstly, in order to testify the feasibility to use NI coil as the secondary winding, the impedance variation of the prototype at different currents and different cycles was tested. The result shows that the impedance increases rapidly with the current rises. Then the iSFCL prototype was tested in a 40 V rms/ 3.3 kA peak short circuit experiment platform, both of the fault current limiting and recovery property of the iSFCL are discussed.

  17. Performance assessment and optimization of the ITER toroidal field coil joints

    NARCIS (Netherlands)

    Rolando, G.; Foussat, A.; Knaster, J.; Ilyin, Y.; Nijhuis, Arend

    2013-01-01

    The ITER toroidal field (TF) system features eighteen coils that will provide the magnetic field necessary to confine the plasma. Each winding pack is composed of seven double pancakes (DP) connected through praying hands joints. Shaking hands joints are used to interface the terminals of the

  18. Wind energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role wind energy may have in the energy future of the US. The topics discussed in the chapter include historical aspects of wind energy use, the wind energy resource, wind energy technology including intermediate-size and small wind turbines and intermittency of wind power, public attitudes toward wind power, and environmental, siting and land use issues

  19. Coil Migration through a Neuroform 3 Stent during Endovascular Coiling. A Case Report.

    LENUS (Irish Health Repository)

    O'Hare, A

    2009-07-29

    Summary: A 43-year-old woman attended for stent assisted coiling. A Neuroform 30 x 4.5 mm stent had been successfully placed over the left periophthalmic aneurysm. During the coiling the first coil migrated through the crowns in the stent, lodging at the MCA bifurcation. We believe that the coil herniated through the overlying stent due to the carotid siphon curvature and the open cell design. Furthermore the distal markers of the stent impeded coil extraction with a MERCI device.

  20. Tension layer winding of cable-in-conduit conductor

    International Nuclear Information System (INIS)

    Devernoe, A.; Ciancetta, G.; King, M.; Parizh, M.; Painter, T.; Miller, J.

    1996-01-01

    A 710 mm i.d. by 440 mm long, 6 layer Cable-in-Conduit (CIC) coil was precision tension layer wound with Incoloy 908 jacketed conductor to model winding technology that will be used for the Nb 3 Sn outsert coils of the 45 Tesla Hybrid Magnet Project at the US National High Magnetic Field Laboratory. This paper reports on the set up of a new winding facility with unique capabilities for insulating and winding long length CIC conductor and on special procedures which were developed to wind and support layer to layer transitions and to safely form conductor into and out of the winding. Analytical methods used to predict conduit keystoning, springback and back tensioning requirements before winding are reported in comparison to results obtained during winding and actual winding build-up dimensions on a layer by layer basis in comparison to design requirements

  1. An inflatable surface coil for rectal imaging

    International Nuclear Information System (INIS)

    Martin, J.F.; Hajek, P.C.; Baker, L.L.; Gylys-Morin, V.; Mattrey, R.F.

    1986-01-01

    Surface coils have become ubiquitous in MR imaging of the body because of substantial gains in signal-to-noise ratio. Unfortunately, there are some anatomic regions, such as the prostate, for which surface coils have insufficient depth sensitivity. The authors have developed an inflatable, distributed capacitance, passively decoupled surface coil which is collapsed for insertion and reinflated for imaging. Images of the prostate are dramatically improved due to proximity of the coil. Lesions in cadaver specimens were observed which were not seen with body coil imaging. Clinical trials are expected to begin in September

  2. Study of transient behavior of finned coil heat exchangers

    Science.gov (United States)

    Rooke, S. P.; Elissa, M. G.

    1993-01-01

    The status of research on the transient behavior of finned coil cross-flow heat exchangers using single phase fluids is reviewed. Applications with available analytical or numerical solutions are discussed. Investigation of water-to-air type cross-flow finned tube heat exchangers is examined through the use of simplified governing equations and an up-wind finite difference scheme. The degenerate case of zero air-side capacitance rate is compared with available exact solution. Generalization of the numerical model is discussed for application to multi-row multi-circuit heat exchangers.

  3. Treatment of unruptured vertebral dissecting aneurysms: internal trapping or stent-assisted coiling.

    Science.gov (United States)

    Li, Hui; Li, Xi-Feng; Zhang, Xin; He, Xu-Ying; Duan, Chuan-Zhi; Liu, Yan-Chao

    2016-01-01

    Endovascular treatment is an attractive approach for the treatment of unruptured vertebral dissecting aneurysms, and includes internal trapping and stent-assisted coil embolization. However, the optimal therapy remains debatable. We reviewed our experience with both endovascular treatment modalities and compared the safety, efficacy, and short-term outcomes for each approach. We retrospectively reviewed 65 consecutive patients with unruptured vertebral dissecting aneurysms who underwent endovascular treatment between January 2003 and January 2014. 24 patients underwent endovascular internal trapping (group A) while 41 patients underwent stent-assisted coiling (group B). Thirteen patients underwent single stent with coiling while 28 patients underwent double or three stent-assisted coiling. Short-term outcomes were evaluated using the modified Rankin Scale. A favorable clinical outcome was achieved in 58 of 65 patients. Procedure-related complications included ischemic symptoms (n = 6) and recurrence (n = 4). There was no statistical difference in modified Rankin Scale scoring between groups. Group A patients had more ischemia symptoms compared with group B patients (p = 0.043), Group B patients had higher recurrence rates compared with group A patients, but the difference had no statistical significance (p = 1.00). However, recurrence only occurred in patients who underwent stent-assisted coiling alone (p = 0.046). Stent-assisted coiling for unruptured vertebral dissecting aneurysms may maintain artery patency. Multilayer disposition of stents with coils may decrease complications and facilitate aneurysm occlusion. Larger, prospective studies are necessary to determine the long-term outcomes of reconstructive therapy.

  4. Coiled transmission line pulse generators

    Science.gov (United States)

    McDonald, Kenneth Fox

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  5. The Modeling and Simulation of Thermal Analysis at Hydro Generator Stator Winding Insulation

    Directory of Open Access Journals (Sweden)

    Mihaela Raduca

    2006-10-01

    Full Text Available This paper presents the modelling and simulation of thermal analysis at hydro generator stator winding. The winding stator is supplied at high voltage of 11 kV for high power hydro generator. To present the thermal analysis for stator winding is presented at supply of coil by 11 kV, when coil is heat and thermal transfer in insulation at ambient temperature.

  6. Convergently-evolved structural anomalies in the coiled coil domains of insect silk proteins.

    Science.gov (United States)

    Sutherland, Tara D; Trueman, Holly E; Walker, Andrew A; Weisman, Sarah; Campbell, Peter M; Dong, Zhaoming; Huson, Mickey G; Woodhead, Andrea L; Church, Jeffrey S

    2014-06-01

    The use of coiled coil proteins as the basis of silk materials is an engineering solution that has evolved convergently in at least five insect lineages-the stinging hymenopterans (ants, bees, hornets), argid sawflies, fleas, lacewings, and praying mantises-and persisted throughout large radiations of these insect families. These coiled coil silk proteins share a characteristic distinct from other coiled coil proteins, in that they are fabricated into solid materials after accumulating as highly concentrated solutions within dedicated glands. Here, we relate the amino acid sequences of these proteins to the secondary and tertiary structural information available from biophysical methods such as X-ray scattering, nuclear magnetic resonance and Raman spectroscopy. We investigate conserved and convergently evolved features within these proteins and compare these to the features of classic coiled coil proteins including tropomyosin and leucine zippers. Our analysis finds that the coiled coil domains of insect silk proteins have several common structural anomalies including a high prevalence of alanine residues in core positions. These atypical features of the coiled coil fibrous proteins - which likely produce deviations from canonical coiled-coil structure - likely exist due to selection pressures related to the process of silk fabrication and the final function of the proteins. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  7. Structural implications of conserved aspartate residues located in tropomyosin's coiled-coil core.

    Science.gov (United States)

    Moore, Jeffrey R; Li, Xiaochuan; Nirody, Jasmine; Fischer, Stefan; Lehman, William

    2011-09-01

    Polar residues lying between adjacent α-helical chains of coiled-coils often contribute to coiled-coil curvature and flexibility, while more typical core hydrophobic residues anneal the chains together. In tropomyosins, ranging from smooth and skeletal muscle to cytoplasmic isoforms, a highly conserved Asp at residue 137 places negative charges within the tropomyosin coiled-coil core in a position which may affect the conformation needed for tropomyosin binding and regulatory movements on actin. Proteolytic susceptibility suggested that substituting a canonical Leu for the naturally occurring Asp at residue 137 increases inter-chain rigidity by stabilizing the tropomyosin coiled-coil. Using molecular dynamics, we now directly assess changes in coiled-coil curvature and flexibility caused by such mutants. Although the coiled-coil flexibility is modestly diminished near the residue 137 mutation site, as expected, a delocalized increase in flexibility along the overall coiled-coil is observed. Even though the average shape of the D137L tropomyosin is straighter than that of wild-type tropomyosin, it is still capable of binding actin due to this increase in flexibility. We conclude that the conserved, non-canonical Asp-137 destabilizes the local structure resulting in a local flexible region in the middle of tropomyosin that normally is important for tropomyosin steady-state equilibrium position on actin.

  8. Exploring alternate states and oligomerization preferences of coiled-coils by de novo structure modeling.

    Science.gov (United States)

    Rämisch, Sebastian; Lizatović, Robert; André, Ingemar

    2015-02-01

    Homomeric coiled-coils can self-assemble into a wide range of structural states with different helix topologies and oligomeric states. In this study, we have combined de novo structure modeling with stability calculations to simultaneously predict structure and oligomeric states of homomeric coiled-coils. For dimers an asymmetric modeling protocol was developed. Modeling without symmetry constraints showed that backbone asymmetry is important for the formation of parallel dimeric coiled-coils. Collectively, our results demonstrate that high-resolution structure of coiled-coils, as well as parallel and antiparallel orientations of dimers and tetramers, can be accurately predicted from sequence. De novo modeling was also used to generate models of competing oligomeric states, which were used to compare stabilities and thus predict the native stoichiometry from sequence. In a benchmark set of 33 coiled-coil sequences, forming dimers to pentamers, up to 70% of the oligomeric states could be correctly predicted. The calculations demonstrated that the free energy of helix folding could be an important factor for determining stability and oligomeric state of homomeric coiled-coils. The computational methods developed here should be broadly applicable to studies of sequence-structure relationships in coiled-coils and the design of higher order assemblies with improved oligomerization specificity. © 2014 Wiley Periodicals, Inc.

  9. Growth Factor Identity Is Encoded by Discrete Coiled-Coil Rotamers in the EGFR Juxtamembrane Region.

    Science.gov (United States)

    Doerner, Amy; Scheck, Rebecca; Schepartz, Alanna

    2015-06-18

    Binding of transforming growth factor α (TGF-α) to the epidermal growth factor receptor (EGFR) extracellular domain is encoded through the formation of a unique antiparallel coiled coil within the juxtamembrane segment. This new coiled coil is an "inside-out" version of the coiled coil formed in the presence of epidermal growth factor (EGF). A third, intermediary coiled-coil interface is formed in the juxtamembrane region when EGFR is stimulated with betacellulin. The seven growth factors that activate EGFR in mammalian systems (EGF, TGF-α, epigen, epiregulin, betacellulin, heparin-binding EGF, and amphiregulin) fall into distinct categories in which the structure of the coiled coil induced within the juxtamembrane region correlates with cell state. The observation that coiled-coil state tracks with the downstream signaling profiles for each ligand provides evidence for growth factor functional selectivity by EGFR. Encoding growth factor identity in alternative coiled-coil rotamers provides a simple and elegant method for communicating chemical information across the plasma membrane. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Comparison between measured and numerically calculated AC losses in second-generation high temperature superconductor pancake coils

    International Nuclear Information System (INIS)

    Zhao, Y.; Fang, J.; Zhang, W.; Zhao, J.; Sheng, L.

    2011-01-01

    The critical current and alternating current loss of HTS coil are not equal in different parts of HTS coil. AC loss inside the magnet forms a certain distribution which makes the winding loss calculation very complex. The analytical expressions are established based on Kim's model and the Clem model. The AC loss of HTS coil is measured by electrical method at 77 K and numerical calculation model is resolved by Matlab. The theoretical results and measurement data were compared and analyzed. As a high temperature superconductor (HTS) coil is a complex electromagnetic system, the critical current and alternating current loss are not equal in different parts of HTS coil. AC loss inside the magnet forms a certain distribution which makes the winding loss calculation very complex. The analytical expressions are established based on Kim's model and the Clem model. The AC loss of high-temperature superconductor pancake coil is generally obtained from experimental measurements and numerical calculations. The AC loss of high-temperature superconductor pancake coil is measured by electrical method at the temperature of liquid nitrogen. Numerical calculation model, which is set up and resolved by Matlab, was given as the theory equation in this study, where the theoretical results and measurement data were compared and analyzed.

  11. Remarkable weakness against cleavage stress for YBCO-coated conductors and its effect on the YBCO coil performance

    International Nuclear Information System (INIS)

    Yanagisawa, Y.; Nakagome, H.; Takematsu, T.; Takao, T.; Sato, N.; Takahashi, M.; Maeda, H.

    2011-01-01

    Cleavage strength for YBCO-coated conductor is extremely low, typically 0.5 MPa. The remarkable weakness is due to cracks on the slit edge of the conductor. The cleavage stress appears on YBCO double pancake coils impregnated with epoxy. The cleavage stress should be avoided in the coil winding. Cleavage strength for an YBCO-coated conductor at 77 K was investigated with a model experiment. The nominal cleavage strength for an YBCO-coated conductor is extremely low, typically 0.5 MPa. This low nominal cleavage strength is due to stress concentration on a small part of the YBCO-coated conductor in cleavage fracture. Debonding by the cleavage stress occurs at the interface between the buffer layer and the Hastelloy substrate. The nominal cleavage strength for a slit edge of the conductor is 2.5-times lower than that for the original edge of the conductor; cracks and micro-peel existing over the slit edge reduce the cleavage strength for the slit edge. Cleavage stress and peel stress should be avoided in coil winding, as they easily delaminate the YBCO-coated conductor, resulting in substantial degradation of coil performance. These problems are especially important for epoxy impregnated YBCO-coated conductor coils. It appears that effect of cleavage stress and peel stress are mostly negligible for paraffin impregnated YBCO-coated conductor coils or dry wound YBCO-coated conductor coils.

  12. Stent-assisted coiling versus coiling alone in unruptured intracranial aneurysms in the matrix and platinum science trial: safety, efficacy, and mid-term outcomes.

    Science.gov (United States)

    Hetts, S W; Turk, A; English, J D; Dowd, C F; Mocco, J; Prestigiacomo, C; Nesbit, G; Ge, S G; Jin, J N; Carroll, K; Murayama, Y; Gholkar, A; Barnwell, S; Lopes, D; Johnston, S C; McDougall, C

    2014-04-01

    Stent-assisted coiling may result in less aneurysm recanalization but more complications than coiling alone. We evaluated outcomes of coiling with and without stents in the multicenter Matrix and Platinum Science Trial. All patients in the Matrix and Platinum Science Trial with unruptured intracranial aneurysms treated per protocol were included. Baseline patient and aneurysm characteristics, procedural details, neurologic outcomes, angiographic outcomes, and safety data were analyzed. Overall, 137 of 361 (38%) patients were treated with a stent. Stent-coiled aneurysms had wider necks (≥4 mm in 62% with stents versus 33% without, P < .0001) and lower dome-to-neck ratios (1.3 versus 1.8, P < .0001). Periprocedural serious adverse events occurred infrequently in those treated with and without stents (6.6% versus 4.5%, P = .39). At 1 year, total significant adverse events, mortality, and worsening of mRS were similar in treatment groups, but ischemic strokes were more common in stent-coiled patients than in coiled patients (8.8% versus 2.2%, P = .005). However, multivariate analysis confirmed that at 2 years after treatment, prior cerebrovascular accident (OR, 4.7; P = .0089) and aneurysm neck width ≥4 mm (OR, 4.5; P = .02) were the only independent predictors of ischemic stroke. Stent use was not an independent predictor of ischemic stroke at 2 years (OR, 1.1; P = .94). Stent use did not predict target aneurysm recurrence at 2 years, but aneurysm dome size ≥10 mm (OR, 9.94; P < .0001) did predict target aneurysm recurrence. Stent-coiling had similar outcomes as coiling despite stented aneurysms having more difficult morphology than coiled aneurysms. Increased ischemic events in stent-coiled aneurysms were attributable to baseline risk factors and aneurysm morphology.

  13. A repeated coiled-coil interruption in the Escherichia coli condensin MukB.

    Science.gov (United States)

    Weitzel, Christopher S; Waldman, Vincent M; Graham, Travis A; Oakley, Martha G

    2011-12-09

    MukB, a divergent structural maintenance of chromosomes (SMC) protein, is important for chromosome segregation and condensation in Escherichia coli and other γ-proteobacteria. MukB and canonical SMC proteins share a common five-domain structure in which globular N- and C-terminal regions combine to form an ATP-binding-cassette-like ATPase domain. This ATPase domain is connected to a central, globular dimerization domain by a long antiparallel coiled coil. The structures of both globular domains have been solved recently. In contrast, little is known about the coiled coil, in spite of its clear importance for SMC function. Recently, we identified interacting regions on the N- and C-terminal halves of the MukB coiled coil through photoaffinity cross-linking experiments. On the basis of these low-resolution experimental constraints, phylogenetic data, and coiled-coil prediction analysis, we proposed a preliminary model in which the MukB coiled coil is divided into multiple segments. Here, we use a disulfide cross-linking assay to detect paired residues on opposite strands of MukB's coiled coil. This method provides accurate register data and demonstrates the presence of at least five coiled-coil segments in this domain. Moreover, these studies show that the segments are interrupted by a repeated, unprecedented deviation from canonical coiled-coil structure. These experiments provide a sufficiently detailed view of the MukB coiled coil to allow rational manipulation of this region for the first time, opening the door for structure-function studies of this domain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Cerebral vasospasm patterns following aneurysmal subarachnoid hemorrhage: an angiographic study comparing coils with clips.

    Science.gov (United States)

    Jones, J; Sayre, J; Chang, R; Tian, J; Szeder, V; Gonzalez, N; Jahan, R; Vinuela, F; Duckwiler, G; Tateshima, S

    2015-11-01

    Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (aSAH) results in significant morbidity due to ischemia. Subarachnoid hematoma evacuation during aneurysm clipping reduces the incidence of vasospasm. However, studies comparing endovascular coiling with open clipping have reported similar rates of spasm. We addressed the question of how coiling produces similar (if not less) vasospasm without the benefit of clot evacuation by evaluating vasospasm patterns among patients with aSAH. We hypothesize that cerebrospinal fluid (CSF) circulation plays a major role in clearing blood breakdown products, and that coiling may preserve CSF flow in the subarachnoid space. A retrospective chart review identified 36 (18 coiled/18 clipped) patients with aSAH who developed angiographic vasospasm. The degree of spasm was quantified using an ordinal scale from 0 (none) to 5 (severe) for 26 anatomic vessel segments evaluated on 164 successive angiograms. Statistical analysis was performed using the Fisher exact test for proportions and the Wilcoxon and Student t tests on ordinal/continuous measures. Quadratic regression was also used as a model for spasm activity versus post-bleed days. In both the coiling and clipping groups the most severely spastic vessels were located adjacent to aneurysm rupture. Perianeurysmal spasm affected all subjects. However, whereas spasm remained largely confined in patients treated by clipping, those who underwent coiling developed stepwise progression distally over time. The distal vasospasm severity scores were higher among subjects treated by coiling, particularly in the most dependent regions of the subarachnoid space. Patients with aSAH treated by endovascular coiling and surgical clipping demonstrate distinct vasospasm patterns. While both initially exhibit perianeurysmal spasm, patients treated by coiling go on to develop stepwise progression distally over time. This finding may reflect dispersion of blood breakdown products along

  15. Remote maintenance of tandem mirror hybrid coils

    International Nuclear Information System (INIS)

    Dietz, L.P.

    1983-01-01

    Hybrid Coils (superconducting coils with normal conducting inserts) are being employed with increasing frequency on Tandem Mirror Devices to obtain high field strengths. The normal conducting copper inserts are short lived in comparison to their encircling superconductors. It becomes desirable, therefore, to devise design features and maintenance procedures to replace the inner normal conducting coils without simultaneously replacing the longer lived (and significantly more costly) superconducting coils. The high neutron wall loadings require that the task be accomplished by remote control. The approach is to permanently mount the coil assemblies on track mounted carriages which serve, during machine operation merely as structural supports, but during maintenance procedures as moveable transport devices. The carriages incorporate all necessary provisions to facilitate remote maintenance operations and to adjust and align the coil assemblies with respect to adjacent machine components. The vacuum vessel is severed on both sides of the hybrid coil by means of a remote cutting machine. The entire coil is transported horizontally, normal to the machine axis to a nearby repair station. Prepositioned carriage mounted repair equipment at the repair station withdraws the damaged normal coil as a single entity and inserts a preassembled spare unit. The repaired hybrid coil is reassembled to the reactor. A cost and risk effective procedure has been evolved to maintain one of the more critical components of a Tandem Mirror Machine

  16. Large coil test facility conceptual design report

    International Nuclear Information System (INIS)

    Nelms, L.W.; Thompson, P.B.; Mann, T.L.

    1978-02-01

    In the development of a superconducting toroidal field (TF) magnet for The Next Step (TNS) tokamak reactor, several different TF coils, about half TNS size, will be built and tested to permit selection of a design and fabrication procedure for full-scale TNS coils. A conceptual design has been completed for a facility to test D-shaped TF coils, 2.5 x 3.5-m bore, operating at 4-6 K, cooled either by boiling helium or by forced-flow supercritical helium. Up to six coils can be accommodated in a toroidal array housed in a single vacuum tank. The principal components and systems in the facility are an 11-m vacuum tank, a test stand providing structural support and service connections for the coils, a liquid nitrogen system, a system providing helium both as saturated liquid and at supercritical pressure, coils to produce a pulsed vertical field at any selected test coil position, coil power supplies, process instrumentation and control, coil diagnostics, and a data acquisition and handling system. The test stand structure is composed of a central bucking post, a base structure, and two horizontal torque rings. The coils are bolted to the bucking post, which transmits all gravity loads to the base structure. The torque ring structure, consisting of beams between adjacent coils, acts with the bucking structure to react all the magnetic loads that occur when the coils are energized. Liquid helium is used to cool the test stand structure to 5 K to minimize heat conduction to the coils. Liquid nitrogen is used to precool gaseous helium during system cooldown and to provide thermal radiation shielding

  17. Antenatal umbilical coiling index as a predictor of perinatal outcome.

    Science.gov (United States)

    Mittal, Ankita; Nanda, Smiti; Sen, Jyotsna

    2015-04-01

    To evaluate the relationship between sonographic measurements of umbilical cord coiling index during late second trimester of pregnancy and perinatal outcome. This prospective study was conducted on two hundred pregnant women with uncomplicated, singleton pregnancy between 20 to 24 weeks of gestation. The antenatal umbilical coiling index (UCI) was calculated by doing a transabdominal ultrasound at the time of induction into the study as the reciprocal of the pitch of one complete vascular coil. The patients were followed up till delivery and any adverse antenatal and/or perinatal event was noted. The mean value for the UCI was noted to be 0.36 + 0.07 coils/cm with a 95% CI of 0.35-0.37. The values for the 10th and the 90th percentile were 0.26 and 0.46 coils/cm respectively. Accordingly the cases were divided into three groups- hypocoiled (UCI UCI between 10th-90th percentile)-162 and hypercoiled (UCI >90th percentile)-20. Hypocoiling was observed to be significantly associated with preterm labour pains (P value 0.0344), oligohydramnios (P value 0.0021), intrapartum foetal heart rate abnormalities (P value 0.0012), instrumental vaginal delivery (P value 0.0275) and low birth weight (P value 0.0344). Hypercoiling was found to be significantly associated with intrauterine growth restriction (P value 0.0323), foetal heart rate abnormalities during labour (0.0399) and low birth weight (P value 0.0095). Abnormal umbilical coiling index in the form of either hypo- or hypercoiling is associated with several adverse antenatal and neonatal outcomes.

  18. The coiled coils of cohesin are conserved in animals, but not in yeast.

    Directory of Open Access Journals (Sweden)

    Glenn E White

    Full Text Available The SMC proteins are involved in DNA repair, chromosome condensation, and sister chromatid cohesion throughout Eukaryota. Long, anti-parallel coiled coils are a prominent feature of SMC proteins, and are thought to serve as spacer rods to provide an elongated structure and to separate domains. We reported recently that the coiled coils of mammalian condensin (SMC2/4 showed moderate sequence divergence (approximately 10-15% consistent with their functioning as spacer rods. The coiled coils of mammalian cohesins (SMC1/3, however, were very highly constrained, with amino acid sequence divergence typically <0.5%. These coiled coils are among the most highly conserved mammalian proteins, suggesting that they make extensive contacts over their entire surface.Here, we broaden our initial analysis of condensin and cohesin to include additional vertebrate and invertebrate organisms and multiple species of yeast. We found that the coiled coils of SMC1/3 are highly constrained in Drosophila and other insects, and more generally across all animal species. However, in yeast they are no more constrained than the coils of SMC2/4 and Ndc80/Nuf2p, suggesting that they are serving primarily as spacer rods.SMC1/3 functions for sister chromatid cohesion in all species. Since its coiled coils apparently serve only as spacer rods in yeast, it is likely that this is sufficient for sister chromatid cohesion in all species. This suggests an additional function in animals that constrains the sequence of the coiled coils. Several recent studies have demonstrated that cohesin has a role in gene expression in post-mitotic neurons of Drosophila, and other animal cells. Some variants of human Cornelia de Lange Syndrome involve mutations in human SMC1/3. We suggest that the role of cohesin in gene expression may involve intimate contact of the coiled coils of SMC1/3, and impose the constraint on sequence divergence.

  19. Development of a new error field correction coil (C-coil) for DIII-D

    International Nuclear Information System (INIS)

    Robinson, J.I.; Scoville, J.T.

    1995-12-01

    The C-coil recently installed on the DIII-D tokamak was developed to reduce the error fields created by imperfections in the location and geometry of the existing coils used to confine, heat, and shape the plasma. First results from C-coil experiments include stable operation in a 1.6 MA plasma with a density less than 1.0 x 10 13 cm -3 , nearly a factor of three lower density than that achievable without the C-coil. The C-coil has also been used in magnetic braking of the plasma rotation and high energy particle confinement experiments. The C-coil system consists of six individual saddle coils, each 60 degree wide toroidally, spanning the midplane of the vessel with a vertical height of 1.6 m. The coils are located at a major radius of 3.2 m, just outside of the toroidal field coils. The actual shape and geometry of each coil section varied somewhat from the nominal dimensions due to the large number of obstructions to the desired coil path around the already crowded tokamak. Each coil section consists of four turns of 750 MCM insulated copper cable banded with stainless steel straps within the web of a 3 in. x 3 in. stainless steel angle frame. The C-coil structure was designed to resist peak transient radial forces (up to 1,800 Nm) exerted on the coil by the toroidal and ploidal fields. The coil frames were supported from existing poloidal field coil case brackets, coil studs, and various other structures on the tokamak

  20. Critical evaluation of in silico methods for prediction of coiled-coil domains in proteins.

    Science.gov (United States)

    Li, Chen; Ching Han Chang, Catherine; Nagel, Jeremy; Porebski, Benjamin T; Hayashida, Morihiro; Akutsu, Tatsuya; Song, Jiangning; Buckle, Ashley M

    2016-03-01

    Coiled-coils refer to a bundle of helices coiled together like strands of a rope. It has been estimated that nearly 3% of protein-encoding regions of genes harbour coiled-coil domains (CCDs). Experimental studies have confirmed that CCDs play a fundamental role in subcellular infrastructure and controlling trafficking of eukaryotic cells. Given the importance of coiled-coils, multiple bioinformatics tools have been developed to facilitate the systematic and high-throughput prediction of CCDs in proteins. In this article, we review and compare 12 sequence-based bioinformatics approaches and tools for coiled-coil prediction. These approaches can be categorized into two classes: coiled-coil detection and coiled-coil oligomeric state prediction. We evaluated and compared these methods in terms of their input/output, algorithm, prediction performance, validation methods and software utility. All the independent testing data sets are available at http://lightning.med.monash.edu/coiledcoil/. In addition, we conducted a case study of nine human polyglutamine (PolyQ) disease-related proteins and predicted CCDs and oligomeric states using various predictors. Prediction results for CCDs were highly variable among different predictors. Only two peptides from two proteins were confirmed to be CCDs by majority voting. Both domains were predicted to form dimeric coiled-coils using oligomeric state prediction. We anticipate that this comprehensive analysis will be an insightful resource for structural biologists with limited prior experience in bioinformatics tools, and for bioinformaticians who are interested in designing novel approaches for coiled-coil and its oligomeric state prediction. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  1. AC loss in superconducting wires operating in a wind turbine like generator

    DEFF Research Database (Denmark)

    Seiler, Eugen; Zirngibl, Thomas; Mijatovic, Nenad

    2010-01-01

    We have manufactured a small circular superconducting coil impregnated with epoxy fibreglass. The coil was wound from a Bi-2223/Ag superconducting wire and it was tested in liquid nitrogen at 77 K. Current-voltage characteristic and the AC losses of the coil were measured and compared with the me...... resulted in the same AC loss characteristic. This work was done as a part of the Superwind project which aims to build a series of test coils and a spinning model of a generator to investigate AC loss and stability of the coils in wind turbine like conditions....

  2. A study on electromagnetic and mechanical characteristics of the field coil in HTS motor

    International Nuclear Information System (INIS)

    Kim, S.B.; Kadota, T.; Joo, J.H.; Sano, H.; Murase, S.; Lee, S.H.; Hong, J.P.; Kim, H.M.; Kwon, Y.K.; Jo, Y.S.

    2010-01-01

    High temperature superconducting (HTS) motors electromagnetically consist of a rotator wound with HTS wires and an armature with conventional copper wires like Litz wire. The HTS rotor windings, as field coils, consist of a straight part and an end-ring part. Because a major rotation torque is induced by an interaction between magnetic fields and current-carrying conductors in the straight part, most of mechanical stresses in the motor occur at the straight part. An end-ring is placed in the edge of the straight part and used to connect to each adjacent straight-part coils. The magnetic fields by coil currents concentrate on the end-ring part, therefore, it is expected that the critical current of the entire coil, straight and end-ring, can be determined by the magnitude of the field in the end-ring. This paper deals with the overall J c degradation in the end-ring part by self-field generated from the coil. In addition to electromagnetic analyses, we have performed a numerical analysis in order to evaluate mechanical stresses in the straight part of field coil by armature reaction on steady-state operation. The analytical results will be presented in this paper.

  3. Argonne National Laboratory superconducting pulsed coil program

    International Nuclear Information System (INIS)

    Wang, S.T.; Kim, S.H.

    1979-01-01

    The main objectives are to develop high current (approx. 100 kA) cryostable cable configurations with reasonably low ac losses, to build a demonstration pulsed coil, and to develop a rather inexpensive large fiberglass reinforced helium cryostat. A 1.5-MJ cryostable pulsed superconducting coil has been developed and constructed at ANL. The coil has a peak field of 4.5 T at an operating current of 11.0 kA. A large inexpensive plastic cryostat has been developed for testing the pulsed coil. The coil has been pulsed with a maximum dB/dt of 11 T/s. The coil was pulsed more than 4000 cycles. Detailed results of the ac loss measurements and the current sharing of the cryostability will be described

  4. Split-coil-system SULTAN

    International Nuclear Information System (INIS)

    Vecsey, G.

    1992-08-01

    The high field superconductor test facility SULTAN started operation successfully in May 1992. Originally designed for testing full scale conductors for the large magnets of the next generation fusion reactors, the SULTAN facility installed at PSI (Switzerland) was designed as a common venture of three European Laboratories: ENEA (Italy), ECN (Netherlands) and PSI, and built by ENEA and PSI in the framework of the Euratom Fusion Technology Program. Presently the largest facility in the world, with its superconducting split coil system generating 11 Tesla in a 0.6 m bore, it is ready now for testing superconductor samples with currents up to 50 kA at variable cooling conditions. Similar tests can be arranged also for other applications. SULTAN is offered by the European Community as a contribution to the worldwide cooperation for the next step of fusion reactor development ITER. First measurements on conductor developed by CEA (Cadarache) are now in progress. Others like those of ENEA and CERN will follow. For 1993, a test of an Italian 12 TZ model coil for fusion application is planned. SULTAN is a worldwide unique facility marking the competitive presence of Swiss technology in the field of applied superconductivity research. Based on development and design of PSI, the high field Nb 3 Sn superconductors and coils were fabricated at the works of Kabelwerke Brugg and ABB, numerous Swiss companies contributed to the success of this international effort. Financing of the Swiss contribution of SULTAN was made available by NEFF, BEW, BBW, PSI and EURATOM. (author) figs., tabs., 20 refs

  5. Radiative MRI Coil Design Using Parasitic Scatterers

    DEFF Research Database (Denmark)

    Sanchez-Heredia, Juan D.; Avendal, Johan; Bibic, Adnan

    2018-01-01

    allows for antenna design techniques to be adapted to RF coil designs. This study proposes the use of parasitic scatterers to improve the performance of an existing 7T MRI coil called the single-sided adapted dipole (SSAD) antenna. The results reveal that scatterers arranged in a Yagi fashion can...... suitable for use in high density arrays. These findings show the potential of parasitic scatterers as an effective method to improve the performance of existing radiative MRI coils....

  6. The structure of the GemC1 coiled coil and its interaction with the Geminin family of coiled-coil proteins.

    Science.gov (United States)

    Caillat, Christophe; Fish, Alexander; Pefani, Dafni Eleftheria; Taraviras, Stavros; Lygerou, Zoi; Perrakis, Anastassis

    2015-11-01

    GemC1, together with Idas and Geminin, an important regulator of DNA-replication licensing and differentiation decisions, constitute a superfamily sharing a homologous central coiled-coil domain. To better understand this family of proteins, the crystal structure of a GemC1 coiled-coil domain variant engineered for better solubility was determined to 2.2 Å resolution. GemC1 shows a less typical coiled coil compared with the Geminin homodimer and the Geminin-Idas heterodimer structures. It is also shown that both in vitro and in cells GemC1 interacts with Geminin through its coiled-coil domain, forming a heterodimer that is more stable that the GemC1 homodimer. Comparative analysis of the thermal stability of all of the possible superfamily complexes, using circular dichroism to follow the unfolding of the entire helix of the coiled coil, or intrinsic tryptophan fluorescence of a unique conserved N-terminal tryptophan, shows that the unfolding of the coiled coil is likely to take place from the C-terminus towards the N-terminus. It is also shown that homodimers show a single-state unfolding, while heterodimers show a two-state unfolding, suggesting that the dimer first falls apart and the helices then unfold according to the stability of each protein. The findings argue that Geminin-family members form homodimers and heterodimers between them, and this ability is likely to be important for modulating their function in cycling and differentiating cells.

  7. Design and fabrication of forced-flow superconducting poloidal coils for the Large Helical Device

    International Nuclear Information System (INIS)

    Nakamoto, K.; Yamamoto, T.; Mizumaki, S.; Yamakoshi, T.; Kanai, Y.; Yamamoto, K.; Wachi, Y.; Ushijima, M.; Yoshida, T.; Kai, T.; Takahata, K.; Yamamoto, J.; Satow, T.; Motojima, O.

    1995-01-01

    Three pairs of superconducting poloidal coils for the LHD (Large Helical Device) have been designed and fabricated using NbTi/Cu cable-in-conduit (CIC) conductors cooled with forced-flow supercritical helium (SHE). In the LHD poloidal coils, high field accuracy as well as high reliability are required. To meet these requirements, detailed field and structural analyses have been performed and key parameters including winding pattern and size and locations of conductor joints have been determined. Compact conductor joint, where NbTi filaments are directly bonded, has also been developed using the solid state bonding technique. (orig.)

  8. Manufacturing development of the Westinghouse Nb3Sn coil for the Large Coil Test Program

    International Nuclear Information System (INIS)

    Young, J.L.; Vota, T.L.; Singh, S.K.

    1983-01-01

    The Westinghouse Nb 3 Sn Magnet for the Oak Ridge National Laboratory Large Coil Program (LCP) is currently well into the manufacturing phase. This paper identifies the manufacturing processes and development tasks for his unique, advanced coil

  9. Effects of five-membered ring amino acid incorporation into peptides for coiled coil formation.

    Science.gov (United States)

    Oba, Makoto; Ito, Chika; Tanaka, Masakazu

    2018-03-01

    A five-membered ring amino acid (Ac 5 c), the peptides of which exhibit a preference for helical secondary structures, was introduced into peptides for the purpose of designing coiled coil peptides with high binding affinities. We prepared five types of peptides containing Ac 5 c with different numbers or at different positions. The incorporation of Ac 5 c into peptides enhanced their α-helicities; however, in contrast to our expectations, it did not result in stable coiled coil formation. The structures of side chains in hydrophobic amino acids, not α-helicities appeared to be important for stable hydrophobic interactions between peptides. Although we were unable to develop coiled coil peptides with high binding affinities, the present results will be useful for designing novel coiled coil peptides. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Transport Vesicle Tethering at the Trans Golgi Network: Coiled Coil Proteins in Action.

    Science.gov (United States)

    Cheung, Pak-Yan P; Pfeffer, Suzanne R

    2016-01-01

    The Golgi complex is decorated with so-called Golgin proteins that share a common feature: a large proportion of their amino acid sequences are predicted to form coiled-coil structures. The possible presence of extensive coiled coils implies that these proteins are highly elongated molecules that can extend a significant distance from the Golgi surface. This property would help them to capture or trap inbound transport vesicles and to tether Golgi mini-stacks together. This review will summarize our current understanding of coiled coil tethers that are needed for the receipt of transport vesicles at the trans Golgi network (TGN). How do long tethering proteins actually catch vesicles? Golgi-associated, coiled coil tethers contain numerous binding sites for small GTPases, SNARE proteins, and vesicle coat proteins. How are these interactions coordinated and are any or all of them important for the tethering process? Progress toward understanding these questions and remaining, unresolved mysteries will be discussed.

  11. A Comparative Study of Orthodontic Coil Springs

    OpenAIRE

    Deepak Kumar Agarwal; Anup Razdan; Abhishek Agarwal; Preeti Bhattacharya; Ankur Gupta; D N Kapoor

    2011-01-01

    Several types of force delivering system are used to carry out tooth movement in orthodontics. Coil springs being one of them are used for the same thus requiring minimal operator manipulation. Aims and objectives : The purpose of this study was to determine the effect of wire diameter, lumen size and length of coil spring on the load produced as a function of displacement of SS and NiTi coil spring. Materials and methods : The study consisted of 60 samples of open and closed coil sprin...

  12. Thomson's Jumping Ring Over a Long Coil

    Science.gov (United States)

    Jeffery, Rondo N.; Amiri, Farhang

    2018-03-01

    The classic jumping ring apparatus consists of a coil with an iron core that extends out of the coil. A copper or aluminum ring placed over the iron core jumps upward when AC power is applied to the coil. In this paper we will examine a modified design of the jumping ring apparatus, called the "long-coil design." It allows the ring to jump upward or downward, depending on the starting position of the ring. These features shed significant light on the study of the force that causes the ring to jump.

  13. Coiled-coil driven membrane fusion: zipper-like vs. non-zipper-like peptide orientation.

    Science.gov (United States)

    Versluis, Frank; Dominguez, Juan; Voskuhl, Jens; Kros, Alexander

    2013-01-01

    Membrane fusion plays a central role in biological processes such as neurotransmission and exocytosis. An important class of proteins that induce membrane fusion are called SNARE (soluble N-ethyl malemeide sensitive factor attachment protein receptors) proteins. To induce membrane fusion, two SNARE proteins embedded in opposing membranes form a four-helix coiled-coil motif together with a third, cytoplasmic, SNARE protein. Coiled-coil formation brings the two membranes into close proximity allowing fusion to occur. Importantly, structural investigations have demonstrated that native membrane fusion only occurs when the orientation of the coiled-coil motif resembles that of a zipper. The zipper orientation arises when parallel coiled-coil formation takes place between peptides that are anchored into apposing membranes at identical termini, thereby forcing the membranes into close contact. Recently, we have designed a synthetic model for membrane fusion, which is based on a set of lipidated coiled-coil forming peptide pairs which are denoted E-K. When incorporated into liposomal membranes, coiled-coil formation between these lipidated peptides induces targeted and efficient membrane fusion of liposomes. Our model system mimics SNARE-driven membrane fusion, as it contains a coiled-coil motif which has a zipper-like orientation, similar to that of the SNARE proteins. Here we investigate whether the zipper-like orientation of the coiled-coil motifs is a prerequisite for membrane fusion in our model system. Our strategy is based on conjugation of the transmembrane anchor to either the N- or the C-terminus of peptides E and K. Whereas the use of a set of complementary peptides with the membrane anchor on identical peptide termini yields the zipper-like orientation of the coiled-coil complex, membrane anchors on opposite peptide termini results in a non-zipper-like coiled-coil orientation. Surprisingly, it was observed that efficient and targeted membrane fusion was

  14. A Non-perturbing Probe of Coiled Coil Formation Based on Electron Transfer Mediated Fluorescence Quenching.

    Science.gov (United States)

    Watson, Matthew D; Peran, Ivan; Raleigh, Daniel P

    2016-07-05

    Coiled coils are abundant in nature, occurring in ∼3% of proteins across sequenced genomes, and are found in proteins ranging from transcription factors to structural proteins. The motif continues to be an important model system for understanding protein-protein interactions and is finding increased use in bioinspired materials and synthetic biology. Knowledge of the thermodynamics of self-assembly, particularly the dissociation constant KD, is essential for the application of designed coiled coils and for understanding the in vivo specificity of natural coiled coils. Standard methods for measuring KD typically rely on concentration dependent circular dichroism (CD). Fluorescence methods are an attractive alternative; however Trp is rarely found in an interior position of a coiled coil, and appending unnatural fluorophores can perturb the system. We demonstrate a simple, non-perturbing method to monitor coiled coil formation using p-cyanophenylalanine (FCN) and selenomethionine (MSe), the Se analogue of Met. FCN fluorescence can be selectively excited and is effectively quenched by electron transfer with MSe. Both FCN and MSe represent minimally perturbing substitutions in coiled coils. MSe quenching of FCN fluorescence is shown to offer a non-perturbing method for following coiled coil formation and for accurately determining dissociation constants. The method is validated using a designed heterodimeric coiled coil. The KD deduced by fluorescence monitored titration is in excellent agreement with the value deduced from concentration dependent CD measurements to within the uncertainty of the measurement. However, the fluorescence approach requires less protein, is less time-consuming, can be applied to lower concentrations and could be applied to high throughput screens.

  15. Design and Fabrication of Helmholtz Coils to Study the Effects of Pulsed Electromagnetic Fields on the Healing Process in Periodontitis: Preliminary Animal Results

    Directory of Open Access Journals (Sweden)

    Haghnegahdar A

    2014-09-01

    Full Text Available Background: Effects of electromagnetic fields on healing have been investigated for centuries. Substantial data indicate that exposure to electromagnetic field can lead to enhanced healing in both soft and hard tissues. Helmholtz coils are devices that generate pulsed electromagnetic fields (PEMF. Objective: In this work, a pair of Helmholtz coils for enhancing the healing process in periodontitis was designed and fabricated. Method: An identical pair of square Helmholtz coils generated the 50 Hz magnetic field. This device was made up of two parallel coaxial circular coils (100 turns in each loop, wound in series which were separated from each other by a distance equal to the radius of one coil (12.5 cm. The windings of our Helmholtz coil was made of standard 0.95mm wire to provide the maximum possible current. The coil was powered by a function generator. Results: The Helmholtz Coils generated a uniform magnetic field between its coils. The magnetic field strength at the center of the space between two coils was 97.6 μT. Preliminary biological studies performed on rats show that exposure of laboratory animals to pulsed electromagnetic fields enhanced the healing of periodontitis. Conclusion: Exposure to PEMFs can lead to stimulatory physiological effects on cells and tissues such as enhanced healing of periodontitis.

  16. Moving coil-based actuators

    Science.gov (United States)

    Neff, Edward A.

    2002-09-01

    SMAC Corporation manufactures a wide variety of moving coil based electric servo actuators. These actuators were developed with a specific purpose in mind: To produce tools that would make the automation of assembly easier to accomplish, tools that could perform work in much the same manner as fingers but with more precision. The design targets were: A. Variable programmable accurate positioning down to sub-micron level. B. Variable programmable accurately controlled speeds. C. Variable programmable forces from grams to kilograms. D. Multiple axis configurations to increase degrees of freedom hence flexibility. E. The ability to perform work and verify its success at the same time. F. A low cost design that could eventually compete with pneumatic devices. (SMAC is related to two large pneumatic manufacturers: SMC Corp. and Mac Valve, Inc.) It should be noted that in the past a number of designers have developed voice coil based actuators, the Stout design and patent, with its discussion of programmable force was an early inspiration. SMAC's basic electro/mechanical and software design patents number 20.

  17. Accommodation of structural rearrangements in the huntingtin-interacting protein 1 coiled-coil domain

    Energy Technology Data Exchange (ETDEWEB)

    Wilbur, Jeremy D., E-mail: jwilbur@msg.ucsf.edu [Graduate Program in Biophysics, University of California, San Francisco, California 94143 (United States); Hwang, Peter K. [Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143 (United States); Brodsky, Frances M. [The G. W. Hooper Foundation, Departments of Microbiology and Immunology and of Bioengineering and Therapeutic Sciences, University of California, San Francisco, California 94143 (United States); Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143 (United States); Fletterick, Robert J. [Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143 (United States); Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143 (United States); Graduate Program in Biophysics, University of California, San Francisco, California 94143 (United States)

    2010-03-01

    Variable packing interaction related to the conformational flexibility within the huntingtin-interacting protein 1 coiled coil domain. Huntingtin-interacting protein 1 (HIP1) is an important link between the actin cytoskeleton and clathrin-mediated endocytosis machinery. HIP1 has also been implicated in the pathogenesis of Huntington’s disease. The binding of HIP1 to actin is regulated through an interaction with clathrin light chain. Clathrin light chain binds to a flexible coiled-coil domain in HIP1 and induces a compact state that is refractory to actin binding. To understand the mechanism of this conformational regulation, a high-resolution crystal structure of a stable fragment from the HIP1 coiled-coil domain was determined. The flexibility of the HIP1 coiled-coil region was evident from its variation from a previously determined structure of a similar region. A hydrogen-bond network and changes in coiled-coil monomer interaction suggest that the HIP1 coiled-coil domain is uniquely suited to allow conformational flexibility.

  18. Multicoil2: Predicting Coiled Coils and Their Oligomerization States from Sequence in the Twilight Zone

    Science.gov (United States)

    Trigg, Jason; Gutwin, Karl; Keating, Amy E.; Berger, Bonnie

    2011-01-01

    The alpha-helical coiled coil can adopt a variety of topologies, among the most common of which are parallel and antiparallel dimers and trimers. We present Multicoil2, an algorithm that predicts both the location and oligomerization state (two versus three helices) of coiled coils in protein sequences. Multicoil2 combines the pairwise correlations of the previous Multicoil method with the flexibility of Hidden Markov Models (HMMs) in a Markov Random Field (MRF). The resulting algorithm integrates sequence features, including pairwise interactions, through multinomial logistic regression to devise an optimized scoring function for distinguishing dimer, trimer and non-coiled-coil oligomerization states; this scoring function is used to produce Markov Random Field potentials that incorporate pairwise correlations localized in sequence. Multicoil2 significantly improves both coiled-coil detection and dimer versus trimer state prediction over the original Multicoil algorithm retrained on a newly-constructed database of coiled-coil sequences. The new database, comprised of 2,105 sequences containing 124,088 residues, includes reliable structural annotations based on experimental data in the literature. Notably, the enhanced performance of Multicoil2 is evident when tested in stringent leave-family-out cross-validation on the new database, reflecting expected performance on challenging new prediction targets that have minimal sequence similarity to known coiled-coil families. The Multicoil2 program and training database are available for download from http://multicoil2.csail.mit.edu. PMID:21901122

  19. Natural templates for coiled-coil biomaterials from praying mantis egg cases.

    Science.gov (United States)

    Walker, Andrew A; Weisman, Sarah; Kameda, Tsunenori; Sutherland, Tara D

    2012-12-10

    Whereas there is growing interest in producing biomaterials containing coiled-coils, relatively few studies have made use of naturally occurring fibrous proteins. In this study, we have characterized fibrous proteins used by mother praying mantises to produce an extensive covering for their eggs called an ootheca and demonstrate the production of artificial ootheca using recombinantly produced proteins. Examination of natural oothecae by infrared spectroscopy and solid-state nuclear magnetic resonance revealed the material to consist of proteins organized predominately as coiled-coils. Two structural proteins, Mantis Fibroin 1 and Mantis Fibroin 2, were identified in ootheca from each of three species. Between species, the primary sequences of both proteins had diverged considerably, but other features were tightly conserved, including low molecular weight, high abundance of Ala, Glu, Lys, and Ser, and a triblock-like architecture with extensive central coiled-coil domain. Mantis fibroin hydrophobic cores had an unusual composition containing high levels of alanine and aromatic residues. Recombinantly produced mantis fibroins folded into coiled-coils in solution and could be fabricated into solid materials with high coiled-coil content. The structural features of mantis fibroins and their straightforward recombinant production make them promising templates for the production of coiled-coil biomimetics materials.

  20. Modulation of Coiled-Coil Dimer Stability through Surface Residues while Preserving Pairing Specificity.

    Science.gov (United States)

    Drobnak, Igor; Gradišar, Helena; Ljubetič, Ajasja; Merljak, Estera; Jerala, Roman

    2017-06-21

    The coiled-coil dimer is a widespread protein structural motif and, due to its designability, represents an attractive building block for assembling modular nanostructures. The specificity of coiled-coil dimer pairing is mainly based on hydrophobic and electrostatic interactions between residues at positions a, d, e, and g of the heptad repeat. Binding affinity, on the other hand, can also be affected by surface residues that face away from the dimerization interface. Here we show how design of the local helical propensity of interacting peptides can be used to tune the stabilities of coiled-coil dimers over a wide range. By designing intramolecular charge pairs, regions of high local helical propensity can be engineered to form trigger sequences, and dimer stability is adjusted without changing the peptide length or any of the directly interacting residues. This general principle is demonstrated by a change in thermal stability by more than 30 °C as a result of only two mutations outside the binding interface. The same approach was successfully used to modulate the stabilities in an orthogonal set of coiled-coils without affecting their binding preferences. The stability effects of local helical propensity and peptide charge are well described by a simple linear model, which should help improve current coiled-coil stability prediction algorithms. Our findings enable tuning the stabilities of coiled-coil-based building modules match a diverse range of applications in synthetic biology and nanomaterials.

  1. LOGICOIL--multi-state prediction of coiled-coil oligomeric state.

    Science.gov (United States)

    Vincent, Thomas L; Green, Peter J; Woolfson, Derek N

    2013-01-01

    The coiled coil is a ubiquitous α-helical protein-structure domain that directs and facilitates protein-protein interactions in a wide variety of biological processes. At the protein-sequence level, the coiled coil is readily recognized via a conspicuous heptad repeat of hydrophobic and polar residues. However, structurally coiled coils are more complicated, existing in a wide range of oligomer states and topologies. As a consequence, predicting these various states from sequence remains an unmet challenge. This work introduces LOGICOIL, the first algorithm to address the problem of predicting multiple coiled-coil oligomeric states from protein-sequence information alone. By covering >90% of the known coiled-coil structures, LOGICOIL is a net improvement compared with other existing methods, which achieve a predictive coverage of ∼31% of this population. This leap in predictive power offers better opportunities for genome-scale analysis, and analyses of coiled-coil containing protein assemblies. LOGICOIL is available via a web-interface at http://coiledcoils.chm.bris.ac.uk/LOGICOIL. Source code, training sets and supporting information can be downloaded from the same site.

  2. Coiled-coil formation on lipid bilayers--implications for docking and fusion efficiency.

    Science.gov (United States)

    Pähler, Gesa; Panse, Cornelia; Diederichsen, Ulf; Janshoff, Andreas

    2012-12-05

    Coiled-coil formation of four different oligopeptides was characterized in solution, on hydrogels, and on membranes by employing circular dichroism spectroscopy, surface plasmon resonance spectroscopy, attenuated total reflection infrared spectroscopy, and ellipsometry. Peptide sequences rich in either glutamic acid (E: E3Cys, i-E3Cys) or lysine (K: K3Cys, i-K3Cys) were used to represent minimal mimics of eukaryotic SNARE motifs. Half of the peptides were synthesized in reverse sequence, so that parallel and antiparallel heptad coiled-coil structures were formed. Either E-peptides or K-peptides were attached covalently to phospholipid anchors via maleimide chemistry, and served as receptors for the recognition of the corresponding binding partners added to solution. Attenuated total reflection infrared spectroscopy of single bilayers confirmed the formation of coiled-coil complexes at the membrane interface. Coiled-coil formation in solution, as compared with association at the membrane surface, displays considerably larger binding constants that are largely attributed to loss of translational entropy at the interface. Finally, the fusogenicity of the various coiled-coil motifs was explored, and the results provide clear evidence that hemifusion followed by full fusion requires a parallel orientation of α-helices, whereas antiparallel oriented coiled-coil motifs display only docking. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Coiled-Coil Formation on Lipid Bilayers—Implications for Docking and Fusion Efficiency

    Science.gov (United States)

    Pähler, Gesa; Panse, Cornelia; Diederichsen, Ulf; Janshoff, Andreas

    2012-01-01

    Coiled-coil formation of four different oligopeptides was characterized in solution, on hydrogels, and on membranes by employing circular dichroism spectroscopy, surface plasmon resonance spectroscopy, attenuated total reflection infrared spectroscopy, and ellipsometry. Peptide sequences rich in either glutamic acid (E: E3Cys, i-E3Cys) or lysine (K: K3Cys, i-K3Cys) were used to represent minimal mimics of eukaryotic SNARE motifs. Half of the peptides were synthesized in reverse sequence, so that parallel and antiparallel heptad coiled-coil structures were formed. Either E-peptides or K-peptides were attached covalently to phospholipid anchors via maleimide chemistry, and served as receptors for the recognition of the corresponding binding partners added to solution. Attenuated total reflection infrared spectroscopy of single bilayers confirmed the formation of coiled-coil complexes at the membrane interface. Coiled-coil formation in solution, as compared with association at the membrane surface, displays considerably larger binding constants that are largely attributed to loss of translational entropy at the interface. Finally, the fusogenicity of the various coiled-coil motifs was explored, and the results provide clear evidence that hemifusion followed by full fusion requires a parallel orientation of α-helices, whereas antiparallel oriented coiled-coil motifs display only docking. PMID:23283228

  4. Structural characteristics of the redox-sensing coiled coil in the voltage-gated H+ channel.

    Science.gov (United States)

    Fujiwara, Yuichiro; Takeshita, Kohei; Nakagawa, Atsushi; Okamura, Yasushi

    2013-06-21

    Oxidation is an important biochemical defense mechanism, but it also elicits toxicity; therefore, oxidation must be under strict control. In phagocytotic events in neutrophils, the voltage-gated H(+) (Hv) channel is a key regulator of the production of reactive oxygen species against invading bacteria. The cytoplasmic domain of the Hv channel forms a dimeric coiled coil underpinning a dimerized functional unit. Importantly, in the alignment of the coiled-coil core, a conserved cysteine residue forms a potential intersubunit disulfide bond. In this study, we solved the crystal structures of the coiled-coil domain in reduced, oxidized, and mutated (Cys → Ser) states. The crystal structures indicate that a pair of Cys residues forms an intersubunit disulfide bond dependent on the redox conditions. CD spectroscopy revealed that the disulfide bond increases the thermal stability of the coiled-coil protein. We also reveal that two thiol modifier molecules are able to bind to Cys in a redox-dependent manner without disruption of the dimeric coiled-coil assembly. Thus, the biochemical properties of the cytoplasmic coiled-coil domain in the Hv channel depend on the redox condition, which may play a role in redox sensing in the phagosome.

  5. Multicoil2: predicting coiled coils and their oligomerization states from sequence in the twilight zone.

    Directory of Open Access Journals (Sweden)

    Jason Trigg

    Full Text Available The alpha-helical coiled coil can adopt a variety of topologies, among the most common of which are parallel and antiparallel dimers and trimers. We present Multicoil2, an algorithm that predicts both the location and oligomerization state (two versus three helices of coiled coils in protein sequences. Multicoil2 combines the pairwise correlations of the previous Multicoil method with the flexibility of Hidden Markov Models (HMMs in a Markov Random Field (MRF. The resulting algorithm integrates sequence features, including pairwise interactions, through multinomial logistic regression to devise an optimized scoring function for distinguishing dimer, trimer and non-coiled-coil oligomerization states; this scoring function is used to produce Markov Random Field potentials that incorporate pairwise correlations localized in sequence. Multicoil2 significantly improves both coiled-coil detection and dimer versus trimer state prediction over the original Multicoil algorithm retrained on a newly-constructed database of coiled-coil sequences. The new database, comprised of 2,105 sequences containing 124,088 residues, includes reliable structural annotations based on experimental data in the literature. Notably, the enhanced performance of Multicoil2 is evident when tested in stringent leave-family-out cross-validation on the new database, reflecting expected performance on challenging new prediction targets that have minimal sequence similarity to known coiled-coil families. The Multicoil2 program and training database are available for download from http://multicoil2.csail.mit.edu.

  6. Design and realization on function of pre-forming and continuous winding for HT-7U special winding machine

    International Nuclear Information System (INIS)

    Yu Jie; Gao Daming; Wen Jun; Zhu Wenhua; Cheng Leping; Tao Yuming

    2000-05-01

    The winding machine is one of the critical facilities for R and D of HT-7U construction. The machine mainly consists of five parts, CICC pay-off spool, a four-rollers straightening assembly, a four-roller forming/bending assembly, continuous winding structure and CNC control system with three-axis CNC control. The facility is needed for CICC magnet fabrication of HT-7U. The main requirements of the winding machine are: continuous winding to reduce number of joints inside the coils; pre-forming CICC conductor to avoid winding with tension; suitable for all TF and PF coils within the scope of various coil shape and dimension limit; improving the configuration tolerance, specially flatness of the CICC conductor. The author emphasizes on the design and realization on function of Pre-forming and Continuous Winding for HT-7U special winding machine. The winding machine with high accuracy has just been developed and applied to the construction of HT-7U model coils

  7. In Vivo Force Decay of Niti Closed Coil Springs

    Science.gov (United States)

    Cox, Crystal; Nguyen, Tung; Koroluk, Lorne; Ko, Ching-Chang

    2014-01-01

    Introduction Nickel-titanium (NiTi) closed coil springs are purported to deliver constant forces over extended ranges of activation and working times. In vivo studies supporting this claim are limited. The objective of this study is to evaluate changes in force decay properties of NiTi closed coil springs after clinical use. Methods Pseudoelastic force-deflection curves for 30 NiTi coil springs (used intra-orally) and 15 matched laboratory control springs (simulated intra-oral conditions - artificial saliva, 37°C) were tested pre- and post-retrieval via Dynamic Mechanical Analysis (DMA) and the Instron machine, respectively, to evaluate amount of force loss and hysteresis change following 4, 8, or 12 weeks of working time (n=10 per group). Effect of the oral environment and clinical use on force properties were evaluated by comparing in vivo and in vitro data. Results The springs studied showed a statistically significant decrease in force (~12%) following 4 weeks of clinical use (pspace closure at an average rate of 0.91mm per month was still observed despite this decrease in force. In vivo and in vitro force loss data were not statistically different. Conclusions NiTi closed coil springs do not deliver constant forces when used intra-orally, but they still allow for space closure rates of ~1mm/month. PMID:24703289

  8. CLOSURE OF HLW TANKS FORMULATION FOR A COOLING COIL GROUT

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J; Vickie Williams, V; Erich Hansen, E

    2008-05-23

    The Tank Closure and Technology Development Groups are developing a strategy for closing the High Level Waste (HLW) tanks at the Savannah River Site (SRS). Two Type IV tanks, 17 and 20 in the F-Area Tank Farm, have been successfully filled with grout. Type IV tanks at SRS do not contain cooling coils; on the other hand, the majority of the tanks (Type I, II, III and IIIA) do contain cooling coils. The current concept for closing tanks equipped with cooling coils is to pump grout into the cooling coils to prevent pathways for infiltrating water after tank closure. This task addresses the use of grout to fill intact cooling coils present in most of the remaining HLW tanks on Site. The overall task was divided into two phases. Phase 1 focused on the development of a grout formulation (mix design) suitable for filling the HLW tank cooling coils. Phase 2 will be a large-scale demonstration of the filling of simulated cooling coils under field conditions using the cooling coil grout mix design recommended from Phase 1. This report summarizes the results of Phase 1, the development of the cooling coil grout formulation. A grout formulation is recommended for the full scale testing at Clemson Environmental Technology Laboratory (CETL) that is composed by mass of 90% Masterflow (MF) 816 (a commercially available cable grout) and 10% blast furnace slag, with a water to cementitious material (MF 816 + slag) ratio of 0.33. This formulation produces a grout that meets the fresh and cured grout requirements detailed in the Task Technical Plan (2). The grout showed excellent workability under continuous mixing with minimal change in rheology. An alternative formulation using 90% MF 1341 and 10% blast furnace slag with a water to cementitious material ratio of 0.29 is also acceptable and generates less heat per gram than the MF 816 plus slag mix. However this MF 1341 mix has a higher plastic viscosity than the MF 816 mix due to the presence of sand in the MF 1341 cable grout and a

  9. Outcomes with single-coil versus dual-coil implantable cardioverter defibrillators: a meta-analysis.

    Science.gov (United States)

    Sunderland, Nicholas; Kaura, Amit; Murgatroyd, Francis; Dhillon, Para; Scott, Paul A

    2018-03-01

    Dual-coil implantable cardioverter defibrillator (ICD) leads have traditionally been used over single-coil leads due to concerns regarding high defibrillation thresholds (DFT) and consequent poor shock efficacy. However, accumulating evidence suggests that this position may be unfounded and that dual-coil leads may also be associated with higher complication rates during lead extraction. This meta-analysis collates data comparing dual- and single-coil ICD leads. Electronic databases were systematically searched for randomized controlled trials (RCT) and non-randomized studies comparing single-coil and dual-coil leads. The mean differences in DFT and summary estimates of the odds-ratio (OR) for first-shock efficacy and the hazard-ratio (HR) for all-cause mortality were calculated using random effects models. Eighteen studies including a total of 138,124 patients were identified. Dual-coil leads were associated with a lower DFT compared to single coil leads (mean difference -0.83J; 95% confidence interval [CI] -1.39--0.27; P = 0.004). There was no difference in the first-shock success rate with dual-coil compared to single-coil leads (OR 0.74; 95%CI 0.45-1.21; P=0.22). There was a significantly lower risk of all-cause mortality associated with single-coil leads (HR 0.91; 95%CI 0.86-0.95; P dual-coil leads. The mortality benefit with single-coil leads most likely represents patient selection bias. Given the increased risk and complexity of extracting dual-coil leads, centres should strongly consider single-coil ICD leads as the lead of choice for routine new left-sided ICD implants. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  10. Designed Coiled-Coil Peptides Inhibit the Type Three Secretion System of Enteropathogenic Escherichia coli

    Science.gov (United States)

    Larzábal, Mariano; Mercado, Elsa C.; Vilte, Daniel A.; Salazar-González, Hector; Cataldi, Angel; Navarro-Garcia, Fernando

    2010-01-01

    Background Enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) are two categories of E. coli strains associated with human disease. A major virulence factor of both pathotypes is the expression of a type three secretion system (TTSS), responsible for their ability to adhere to gut mucosa causing a characteristic attaching and effacing lesion (A/E). The TTSS translocates effector proteins directly into the host cell that subvert mammalian cell biochemistry. Methods/Principal Findings We examined synthetic peptides designed to inhibit the TTSS. CoilA and CoilB peptides, both representing coiled-coil regions of the translocator protein EspA, and CoilD peptide, corresponding to a coiled–coil region of the needle protein EscF, were effective in inhibiting the TTSS dependent hemolysis of red blood cells by the EPEC E2348/69 strain. CoilA and CoilB peptides also reduced the formation of actin pedestals by the same strain in HEp-2 cells and impaired the TTSS-mediated protein translocation into the epithelial cell. Interestingly, CoilA and CoilB were able to block EspA assembly, destabilizing the TTSS and thereby Tir translocation. This blockage of EspA polymerization by CoilA or CoilB peptides, also inhibited the correct delivery of EspB and EspD as detected by immunoblotting. Interestingly, electron microscopy of bacteria incubated with the CoilA peptide showed a reduction of the length of EspA filaments. Conclusions Our data indicate that coiled-coil peptides can prevent the assembly and thus the functionality of the TTSS apparatus and suggest that these peptides could provide an attractive tool to block EPEC and EHEC pathogenesis. PMID:20140230

  11. Status of the cold test facility for the JT-60SA tokamak toroidal field coils

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Maksoud, Walid, E-mail: walid.abdelmaksoud@cea.fr; Bargueden, Patrick; Bouty, André; Dispau, Gilles; Donati, André; Eppelle, Dominique; Genini, Laurent; Guiho, Patrice; Guihard, Quentin; Joubert, Jean-Michel; Kuster, Olivier; Médioni, Damien; Molinié, Frédéric; Sinanna, Armand; Solenne, Nicolas; Somson, Sébastien; Vieillard, Laurence

    2015-10-15

    Highlights: • The 5 K cryogenic loop includes a 500 W refrigerator and a She cold pump. • The coils are energized thanks to a 25.7 kA power supply and HTS current leads. • Temperature margin tests between 5 K and 7.5 K will be made on each coil. • A magnet safety system protects each double pancake of the coil in case of quench. • Instrumentation is monitored on a 1 Hz to 10 kHz fast acquisition system. - Abstract: JT-60SA is a fusion experiment which is jointly constructed by Japan and Europe and which shall contribute to the early realization of fusion energy, by providing support to the operation of ITER, and by addressing key physics issues for ITER and DEMO. In order to achieve these goals, the existing JT-60U experiment will be upgraded to JT-60SA by using superconducting coils. The 18 TF coils of the JT-60SA device will be provided by European industry and tested in a Cold Test Facility (CTF) at CEA Saclay. The coils will be tested at the nominal current of 25.7 kA and will be cooled with supercritical helium between 5 K and 7.5 K to check the temperature margin against a quench. The main objective of these tests is to check the TF coils performance and hence mitigate the fabrication risks. The most important components of the facility are: a 11.5 m × 6.5 m large cryostat in which the TF coils will be thermally insulated by vacuum; a 500 W helium refrigerator and a valve box to cool the coils down to 5 K and circulate 24 g/s of supercritical helium through the winding pack and through the casing; a power supply and HTS current leads to energize the coil; the control and instrumentation equipment (sensors, PLC's, supervision system, fast data acquisition system, etc.) and the Magnet Safety System (MSS) that protects the coils in case of quench. The paper will give an overview of the design of this large facility and the status of its realization.

  12. Coil Optimization for High Temperature Superconductor Machines

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech; Abrahamsen, Asger Bech

    2011-01-01

    This paper presents topology optimization of HTS racetrack coils for large HTS synchronous machines. The topology optimization is used to acquire optimal coil designs for the excitation system of 3 T HTS machines. Several tapes are evaluated and the optimization results are discussed...

  13. Evidence-based pathology: umbilical cord coiling.

    Science.gov (United States)

    Khong, T Y

    2010-12-01

    The generation of a pathology test result must be based on criteria that are proven to be acceptably reproducible and clinically relevant to be evidence-based. This review de-constructs the umbilical cord coiling index to illustrate how it can stray from being evidence-based. Publications related to umbilical cord coiling were retrieved and analysed with regard to how the umbilical coiling index was calculated, abnormal coiling was defined and reference ranges were constructed. Errors and other influences that can occur with the measurement of the length of the umbilical cord or of the number of coils can compromise the generation of the coiling index. Definitions of abnormal coiling are not consistent in the literature. Reference ranges defining hypocoiling or hypercoiling have not taken those potential errors or the possible effect of gestational age into account. Even the way numerical test results in anatomical pathology are generated, as illustrated by the umbilical coiling index, warrants a critical analysis into its evidence base to ensure that they are reproducible or free from errors.

  14. Operator coil monitoring Acceptance Test Procedure

    International Nuclear Information System (INIS)

    Erhart, M.F.

    1995-01-01

    The readiness of the Data Acquisition and Control System (DACS) to provide monitoring and control of the Programmable Logic Controller (PLC) abort coils from the Master and RSS stations will be systematically tested during performance of this procedure. It should be noted that these are not physical abort coils but software coils controlled by the software's ladder logic. The readiness of the DACS to properly interface with the ENRAF wire level gauge installed in the SY-101 storage tank will also be tested. During this test, a verification of all abort coil indications will be conducted at the DACS Development Facility in the 306E Building by injecting an input signal for each DACS sensor that has an associated abort coil until the abort coil actuates, and then ensuring that the status of the abort coil indicated at the Master and RSS stations is correct. Each abort coil will also be tested to ensure that the ''ENABLE'' and ''DISABLE'' controls from the Master and RSS stations function correctly, and only with the use of proper passwords

  15. Magnetic Fields at the Center of Coils

    Science.gov (United States)

    Binder, Philippe; Hui, Kaleonui; Goldman, Jesse

    2014-01-01

    In this note we synthesize and extend expressions for the magnetic field at the center of very short and very long current-carrying coils. Elementary physics textbooks present the following equation for the magnetic field inside a very long current-carrying coil (solenoid): B[subscript sol] = µ[subscript 0] (N/L) I, (1) where I is the current, N…

  16. Toroidal field coils for the PDX machine

    International Nuclear Information System (INIS)

    Bushnell, C.W.

    1975-01-01

    This paper describes the engineering design features of the TF coils for the PDX machine. Included are design details of the electrical insulation, water cooling, and coil segment joint which allows access to the central machine area. A discussion of the problems anticipated in the manufacture and the planned solutions are presented

  17. Optimization of modular coils for stellarator fields

    International Nuclear Information System (INIS)

    Chu, T.K.; Furth, H.P.; Johnson, J.L.; Ludescher, C.; Weimer, K.E.

    1982-02-01

    Introduction of a non-sinusoidal deformation can enhance the efficacy of modular coils for generating magnetic fields with a built-in rotational transform. Techniques are developed that provide an understanding of how specific deformations affect the harmonic content of the magnetic field and thus the properties of the vacuum configuration. This provides an optimization procedure for coil design

  18. The bar coil for NMR tomograph

    International Nuclear Information System (INIS)

    Bogorodzki, P.; Piatkowski, A.; Wasielewski, J.

    1995-01-01

    The bar coil (bi-planar) for the NMR tomograph, designed for medical diagnostics, has been described. The tests of coil shown that it generates good homogenous magnetic field in a big volume what results in improving of the signal-to-noise ratio

  19. Functional investigation of the plant-specific long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC and PICC-LIKE (PICL in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Sowmya Venkatakrishnan

    Full Text Available We have identified and characterized two Arabidopsis long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC and PICC-LIKE (PICL. PICC (147 kDa and PICL (87 kDa are paralogs that consist predominantly of a long coiled-coil domain (expanded in PICC, with a predicted transmembrane domain at the immediate C-terminus. Orthologs of PICC and PICL were found exclusively in vascular plants. PICC and PICL GFP fusion proteins are anchored to the cytoplasmic surface of the endoplasmic reticulum (ER membrane by a C-terminal transmembrane domain and a short tail domain, via a tail-anchoring mechanism. T-DNA-insertion mutants of PICC and PICL as well as the double mutant show an increased sensitivity to the plant abiotic stress hormone abscisic acid (ABA in a post-germination growth response. PICC, but not PICL gene expression is induced by the bacterial pathogen-associated molecular pattern (PAMP flg22. T-DNA insertion alleles of PICC, but not PICL, show increased susceptibility to the non-virulent strain P. syringae pv. tomato DC3000 hrcC, but not to the virulent strain P. syringae pv. tomato DC3000. This suggests that PICC mutants are compromised in PAMP-triggered immunity (PTI. The data presented here provide first evidence for the involvement of a plant long coiled-coil protein in a plant defense response.

  20. Functional investigation of the plant-specific long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL) in Arabidopsis thaliana.

    Science.gov (United States)

    Venkatakrishnan, Sowmya; Mackey, David; Meier, Iris

    2013-01-01

    We have identified and characterized two Arabidopsis long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL). PICC (147 kDa) and PICL (87 kDa) are paralogs that consist predominantly of a long coiled-coil domain (expanded in PICC), with a predicted transmembrane domain at the immediate C-terminus. Orthologs of PICC and PICL were found exclusively in vascular plants. PICC and PICL GFP fusion proteins are anchored to the cytoplasmic surface of the endoplasmic reticulum (ER) membrane by a C-terminal transmembrane domain and a short tail domain, via a tail-anchoring mechanism. T-DNA-insertion mutants of PICC and PICL as well as the double mutant show an increased sensitivity to the plant abiotic stress hormone abscisic acid (ABA) in a post-germination growth response. PICC, but not PICL gene expression is induced by the bacterial pathogen-associated molecular pattern (PAMP) flg22. T-DNA insertion alleles of PICC, but not PICL, show increased susceptibility to the non-virulent strain P. syringae pv. tomato DC3000 hrcC, but not to the virulent strain P. syringae pv. tomato DC3000. This suggests that PICC mutants are compromised in PAMP-triggered immunity (PTI). The data presented here provide first evidence for the involvement of a plant long coiled-coil protein in a plant defense response.

  1. Functional Investigation of the Plant-Specific Long Coiled-Coil Proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL) in Arabidopsis thaliana

    Science.gov (United States)

    Venkatakrishnan, Sowmya; Mackey, David; Meier, Iris

    2013-01-01

    We have identified and characterized two Arabidopsis long coiled-coil proteins PAMP-INDUCED COILED-COIL (PICC) and PICC-LIKE (PICL). PICC (147 kDa) and PICL (87 kDa) are paralogs that consist predominantly of a long coiled-coil domain (expanded in PICC), with a predicted transmembrane domain at the immediate C-terminus. Orthologs of PICC and PICL were found exclusively in vascular plants. PICC and PICL GFP fusion proteins are anchored to the cytoplasmic surface of the endoplasmic reticulum (ER) membrane by a C-terminal transmembrane domain and a short tail domain, via a tail-anchoring mechanism. T-DNA-insertion mutants of PICC and PICL as well as the double mutant show an increased sensitivity to the plant abiotic stress hormone abscisic acid (ABA) in a post-germination growth response. PICC, but not PICL gene expression is induced by the bacterial pathogen-associated molecular pattern (PAMP) flg22. T-DNA insertion alleles of PICC, but not PICL, show increased susceptibility to the non-virulent strain P. syringae pv. tomato DC3000 hrcC, but not to the virulent strain P. syringae pv. tomato DC3000. This suggests that PICC mutants are compromised in PAMP-triggered immunity (PTI). The data presented here provide first evidence for the involvement of a plant long coiled-coil protein in a plant defense response. PMID:23451199

  2. Experimental study on a Nb3Al insert coil under high magnetic field

    Science.gov (United States)

    Zhu, Guang; Dai, Yinming; Cheng, Junsheng; Chang, Kun; Liu, Jianhua; Wang, Qiuliang; Pan, Xifeng; Li, Chao

    2016-06-01

    Nb3Al is one of the most promising superconductors to replace Nb3Sn in large scale, high field superconducting magnet. Since the complicated conductor manufacturing process, long and stable Nb3Al conductor is difficult to acquire in a commercial scale. Based on a 70 m length of Nb-Al precursor conductor, we designed and fabricated a Nb3Al coil. The coil winding, low temperature diffusion heat treatment and epoxy impregnation are described in detail. The finished Nb3Al coil is tested as an insert in a background magnet. The test is performed at the background field from 7 T to 15 T. The test results are analyzed and presented in this paper.

  3. Advanced Examination Techniques Applied to the Assessment of Vacuum Pressure Impregnation (VPI) of ITER Correction Coils

    CERN Document Server

    Sgobba, Stefano; Samain, Valerie; Libeyre, Paul; Cecillon, Alexandre; Dawid, J

    2014-01-01

    The ITER Magnet System includes a set of 18 superconducting correction coils (CC) which are used to compensate the error field modes arising from geometrical deviations caused by manufacturing and assembly tolerances. The turn and ground insulation are electrically insulated with a multi-layer fiberglass polyimide interleaved composite, impregnated with epoxy resin using vacuum pressure impregnation (VPI). Adequate high voltage insulation (5 kV), mechanical strength and rigidity of the winding pack should be achieved after impregnation and curing of the insulation system. VPI is an effective process to avoid defects such dry spots and incomplete wet out. This insulation technology has also been developed since several years for application to large superconducting coils and more recently to ITER CC. It allows the coils to be impregnated without impacting on their functional characteristics. One of the critical challenges associated with the construction of the CC is the qualification of the VPI insulation. Se...

  4. Unruptured Intracranial Aneurysms with Oculomotor Nerve Palsy : Clinical Outcome between Surgical Clipping and Coil Embolization

    Science.gov (United States)

    Nam, Kyoung Hyup; Lee, Jae Il; Ko, Jun Gyeong; Lee, Tae Hong; Lee, Sang Weon

    2010-01-01

    Objective To evaluate the clinical outcome of coil embolization for unruptured intracranial aneurysm (UIA) with oculomotor nerve palsy (ONP) compared with surgical clipping. Methods A total of 19 patients presented with ONP caused by UIAs between Jan 2004 and June 2008. Ten patients underwent coil embolization and nine patients surgical clipping. The following parameters were retrospectively analyzed to evaluate the differences in clinical outcome observed in both coil embolization and surgical clipping : 1) gender, 2) age, 3) location of the aneurysm, 4) duration of the symptom, and 5) degree of ONP. Results Following treatment, complete symptomatic recovery or partial relief from ONP was observed in 15 patients. Seven of the ten patients were treated by coil embolization, compared to eight of the nine patients treated by surgical clipping (p = 0.582). Patient's gender, age, location of the aneurysm, size of the aneurysm, duration of symptom, and degree of the ONP did not statistically correlate with recovery of symptoms between the two groups. No significant differences were observed in mean improvement time in either group (55 days in coil embolization and 60 days in surgical clipping). Conclusion This study indicates that no significant differences were observed in the clinical outcome between coil embolization and surgical clipping techniques in the treatment of aneurysms causing ONP. Coil embolization seems to be more feasible and safe treatment modality for the relief and recovery of oculomotor nerve palsy. PMID:20856657

  5. Startup of Large Coil Test Facility

    International Nuclear Information System (INIS)

    Haubenreich, P.N.; Bohanan, R.E.; Fietz, W.A.; Luton, J.N.; May, J.R.

    1984-01-01

    The Large Coil Test Facility (LCTF) is being used to test superconducting toroidal field coils about one-third the size of those for INTOR. Eventually, six different coils from four countries will be tested. Operations began in 1983 with acceptance testing of the helium refrigerator/liquefier system. Comprehensive shakedown of the facility and tests with the first three coils (from Japan, the United States, and Switzerland) were successfully accomplished in the summer of 1984. Currents up to 10,200 A and fields up to 6.4 T were reached. Data were obtained on performance of refrigerator, helium distribution, power supplies, controls, and data acquisition systems and on the acoustic emission, voltages, currents, and mechanical strains during charging and discharging the coils

  6. Design description of the Large Coil Test Facility pulse-coil support and transport system

    International Nuclear Information System (INIS)

    Queen, C.C.

    1981-01-01

    In order to simulate the transient fields which would be imposed on superconducting toroidal field coils in an operating tokamak reactor, the Large Coil Test Facility (LCTF) test stand includes a set of pulse coils. This set of pulse coils is designed to be moved from one test location to another within the LCTF vacuum vessel while the vessel is operating under vacuum and the test stand and test coils are at an operating temperature of 4.2K. This operating environment and the extremely high magnetic loads have necessitated some unique design features for the pulse coil support and transport system. The support structure for the pulse coil must react high overturning moments and axial loads induced on the pulse coil by the interaction of the pulse field with the field generated by the large test coils. These loads are reacted into the test stand support structure or spider frame by an arrangement of six pedestals and a support beam. In order to move the pulse coil set from one test location to another, the support beam containing the pulse coils must be driven across rollers mounted on the pedestals, then clamped securely to react the loads. Because these operations must be performed in a vacuum environment at cryogenic tmperature, special consideration was given to component design

  7. Gearless wind power generator

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, L.; Ridanpaeae, P.; Vihriaelae, H.; Peraelae, R. [Tampere Univ. of Technology (Finland). Lab. of Electricity and Magnetism

    1998-10-01

    In the project a 100 kW axial flux permanent magnet wind power generator has been designed. The toroidal stator with air gap winding is placed between two rotating discs with permanent magnets. The magnet material is NdBFe due to its excellent magnetic properties compared to other materials. This type of topology enables a very large number of poles compared to conventional machine of the same size. A large number of poles is required to achieve a low rotational speed and consequently a direct driven system. The stator winding is formed by rectangular coils. The end winding is very short leading to small resistive losses. On the other hand, the absence of iron teeth causes eddy current losses in the conductors. These can be restricted to an acceptable level by keeping the wire diameter and flux density small. This means that the number of phases should be large. Several independent three phase systems may be used. The toothless stator also means that the iron losses are small and there exists no cogging torque

  8. Computer program to calculate composite conductor losses in pulsed poloidal coil systems

    International Nuclear Information System (INIS)

    Gray, W.H.; Ballou, J.K.

    1976-01-01

    In the design of the cryogenic system and superconducting magnets for a poloidal field system in a tokamak fusion reactor, it is important to have an accurate estimate of the heat produced in the superconducting magnets as a result of the rapidly changing magnetic fields. Until recently, this estimate was obtained by assuming that the field and the time rate of change of the field were constant throughout the coil windings. A more accurate method of estimation involves integrating the losses over the coil windings, thus taking into account the spatial variation of the magnetic field. A computer code, PLASS (Pulsed Losses in Axisymmetric Superconducting Solenoids), has been written to perform this integration. PLASS has been used to analyze the present design for the poloidal coil system of the ORNL Experimental Power Reactor (EPR). This design requires that superconductor hysteresis losses, superconductor coupling losses, stabilizing material eddy current losses, and structural material eddy current losses be taken into consideration in the calculation of conductor losses. A tabulation of individual losses vs variations in superconductor characteristics and coil current changes is presented to demonstrate the parameters which significantly affect the design. Results indicate that the total energy released into the cryogenic system is less than one-half of that predicted by the previously oversimplified calculation

  9. Simultaneous formation of right- and left-handed anti-parallel coiled-coil interfaces by a coil2 fragment of human lamin A.

    Science.gov (United States)

    Kapinos, Larisa E; Burkhard, Peter; Herrmann, Harald; Aebi, Ueli; Strelkov, Sergei V

    2011-04-22

    The elementary building block of all intermediate filaments (IFs) is a dimer featuring a central α-helical rod domain flanked by the N- and C-terminal end domains. In nuclear IF proteins (lamins), the rod domain consists of two coiled-coil segments, coil1 and coil2, that are connected by a short non-helical linker. Coil1 and the C-terminal part of coil2 contain the two highly conserved IF consensus motifs involved in the longitudinal assembly of dimers. The previously solved crystal structure of a lamin A fragment (residues 305-387) corresponding to the second half of coil2 has yielded a parallel left-handed coiled coil. Here, we present the crystal structure and solution properties of another human lamin A fragment (residues 328-398), which is largely overlapping with fragment 305-387 but harbors a short segment of the tail domain. Unexpectedly, no parallel coiled coil forms within the crystal. Instead, the α-helices are arranged such that two anti-parallel coiled-coil interfaces are formed. The most significant interface has a right-handed geometry, which is accounted for by a characteristic 15-residue repeat pattern that overlays with the canonical heptad repeat pattern. The second interface is a left-handed anti-parallel coiled coil based on the predicted heptad repeat pattern. In solution, the fragment reveals only a weak dimerization propensity. We speculate that the C-terminus of coil2 might unzip, thereby allowing for a right-handed coiled-coil interface to form between two laterally aligned dimers. Such an interface might co-exist with a heterotetrameric left-handed coiled-coil assembly, which is expected to be responsible for the longitudinal A(CN) contact. Copyright © 2011. Published by Elsevier Ltd.

  10. N@a and N@d: Oligomer and Partner Specification by Asparagine in Coiled-Coil Interfaces.

    Science.gov (United States)

    Fletcher, Jordan M; Bartlett, Gail J; Boyle, Aimee L; Danon, Jonathan J; Rush, Laura E; Lupas, Andrei N; Woolfson, Derek N

    2017-02-17

    The α-helical coiled coil is one of the best-studied protein-protein interaction motifs. As a result, sequence-to-structure relationships are available for the prediction of natural coiled-coil sequences and the de novo design of new ones. However, coiled coils adopt a wide range of oligomeric states and topologies, and our understanding of the specification of these and the discrimination between them remains incomplete. Gaps in our knowledge assume more importance as coiled coils are used increasingly to construct biomimetic systems of higher complexity; for this, coiled-coil components need to be robust, orthogonal, and transferable between contexts. Here, we explore how the polar side chain asparagine (Asn, N) is tolerated within otherwise hydrophobic helix-helix interfaces of coiled coils. The long-held view is that Asn placed at certain sites of the coiled-coil sequence repeat selects one oligomer state over others, which is rationalized by the ability of the side chain to make hydrogen bonds, or interactions with chelated ions within the coiled-coil interior of the favored state. We test this with experiments on de novo peptide sequences traditionally considered as directing parallel dimers and trimers, and more widely through bioinformatics analysis of natural coiled-coil sequences and structures. We find that when located centrally, rather than near the termini of such coiled-coil sequences, Asn does exert the anticipated oligomer-specifying influence. However, outside of these bounds, Asn is observed less frequently in the natural sequences, and the synthetic peptides are hyperthermostable and lose oligomer-state specificity. These findings highlight that not all regions of coiled-coil repeat sequences are equivalent, and that care is needed when designing coiled-coil interfaces.

  11. Development of a single-layer Nb3Sn common coil dipole model

    Energy Technology Data Exchange (ETDEWEB)

    Igor Novitski et al.

    2002-12-13

    A high-field dipole magnet based on the common coil design was developed at Fermilab for a future Very Large Hadron Collider. A short model of this magnet with a design field of 11 T in two 40-mm apertures is being fabricated using the react-and-wind technique. In order to study and optimize the magnet design two 165-mm long mechanical models were assembled and tested. A technological model consisting of magnet straight section and ends was also fabricated in order to check the tooling and the winding and assembly procedures. This paper describes the design and technology of the common coil dipole magnet and summarizes the status of short model fabrication.The results of the mechanical model tests and comparison with FE mechanical analysis are also presented.

  12. Compound Tension Control of an Optical-Fiber Coil System: A Cyber-Physical System View

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2014-03-01

    Full Text Available The full-automatic optical-fiber coil winding equipment is a complex electromechanical system which contains signal acquisition, data processing, communications, and motor control. In the complex electromechanical system, the subsystems rely on wired or wireless network technology to complete the real-time perception, coordinate, accurate, and dynamitic control, and information exchange services. The paper points to the full-automatic optical-fiber coil winding equipment with the characteristics of cyber-physical system to research its numerical design. We present a novel compound tension control system based on the experimental platform dSPACE to achieve semiphysical simulation of compound tension control system and examine the functions of control system.

  13. Force generation by orthodontic coil springs.

    Science.gov (United States)

    von Fraunhofer, J A; Bonds, P W; Johnson, B E

    1993-01-01

    Nickel titanium (NiTi) coil springs are a new development in orthodontics, designed to produce light continuous forces. This study compares the force delivery by NiTi open and closed coil springs during unloading (de-activation) to that provided by comparable stainless steel (SS) springs. Open-coil springs (0.010 x 0.035 inch) were compressed from their initial length of 15 mm to 6 mm and the forces generated with spring recovery recorded. Closed-coil springs (0.009 x 0.035 inch) were distracted from their initial length of 3 mm to 9 mm and the force recorded as the spring recovered. The closed-coil NiTi springs produced light continuous forces of 75-90 g over the distraction range of 6 mm while the open-coil springs produced forces of 55-70 g within the 9 mm compression range. SS springs produced heavier forces, ca. 200 g, for an activation of 1 mm and the generated force increased rapidly as the activation was increased. The findings indicate that NiTi coil springs deliver optimal forces for orthodontic tooth movement over a longer activation range than comparable SS springs.

  14. Correcting coils in end magnets of accelerators

    Directory of Open Access Journals (Sweden)

    L. R. P. Kassab

    1998-05-01

    Full Text Available We present an empirical investigation of the correcting coils behavior used to homogenize the field distribution of the race-track microtron accelerator end magnets. These end magnets belong to the second stage of the 30.0 MeV cw electron accelerator under construction at IFUSP, the race-track microtron booster, in which the beam energy is raised from 1.97 to 5.1 MeV. The correcting coils are attached to the pole faces and are based on the inhomogeneities of the magnetic field measured. The performance of these coils, when operating the end magnets with currents that differ by ±10% from the one used in the mappings that originated the coils copper leads, is presented. For one of the magnets, adjusting conveniently the current of the correcting coils makes it possible to homogenize field distributions of different intensities, once their shapes are practically identical to those that originated the coils. For the other one, the shapes are changed and the coils are less efficient. This is related to intrinsic factors that determine the inhomogeneities. However, we obtained uniformity of 0.001% in both cases.

  15. Stabilization of microgrid with intermittent renewable energy sources by SMES with optimal coil size

    International Nuclear Information System (INIS)

    Saejia, M.; Ngamroo, I.

    2011-01-01

    A controller design of a superconducting magnetic energy storage unit is proposed. The structure of a power controller is the practical proportional-integral (PI). The PI parameters and coil size are tuned by a particle swarm optimization. The proposed method is able to effectively alleviate power fluctuations. It is well known that the superconducting coil is the vital part of a superconducting magnetic energy storage (SMES) unit. This paper deals with the power controller design of a SMES unit with an optimal coil size for stabilization of an isolated microgrid. The study microgrid consists of renewable energy sources with intermittent power outputs i.e., wind and photovoltaic. Since power generations from such renewable sources are unpredictable and variable, these result in power fluctuations in a microgrid. To stabilize power fluctuations, a SMES unit with a fast control of active and reactive power can be applied. The structure of a power controller is the practical proportional-integral (PI). Based on the minimization of the variance of power fluctuations from renewable sources as well as the initial stored energy of SMES, the optimal PI parameters and coil size are automatically and simultaneously tuned by a particle swarm optimization. Simulation studies show that the proposed SMES controller with an optimal coil size is able to effectively alleviate power fluctuations under various power patterns from intermittent renewable sources.

  16. Mechanical performance evaluation of the CFETR central solenoid model coil design

    Science.gov (United States)

    Liu, Xiaogang; Wang, Zhaoliang; Ren, Yong; Li, Junjun; Yin, Dapeng; Li, Lei; Gao, Xiang; Wu, Yu

    2018-01-01

    The Chinese Fusion Engineering Test Reactor (CFETR) Central Solenoid Model Coil is being fabricated by the Institute of Plasma Physics Chinese Academy of Sciences. The Model Coil is comprised of Nb3Sn and NbTi modules held together by a preload structure. It will operate at 4.5 K to produce a peak field of 12 T at 48 kA. In order to investigate the feasibility and integrity of the Model Coil design before its manufacturing, the mechanical performance has been evaluated for the room temperature preload, 4.5 K stand-by and 48 kA operating conditions. A 1/15 3D detailed model that consists of jackets, insulations, bladders, buffers and preload structure, is constructed and simulated using the coupled structural-thermal-electromagnetic solver of ANSYS. In contrary to a smeared winding pack model, our analysis with the detailed model can directly and precisely simulate the differential thermal contraction effect of the preload structure, jacket and insulations, as well as the electromagnetic load acting on the jacket. The detailed deformation and stress behaviors of the Model Coil are illustrated and discussed. The results indicate that the final design of the CFETR Central Solenoid Model Coil is reasonably conservative and satisfy the design criteria.

  17. Crystal structure of a coiled-coil domain from human ROCK I.

    Directory of Open Access Journals (Sweden)

    Daqi Tu

    2011-03-01

    Full Text Available The small GTPase Rho and one of its targets, Rho-associated kinase (ROCK, participate in a variety of actin-based cellular processes including smooth muscle contraction, cell migration, and stress fiber formation. The ROCK protein consists of an N-terminal kinase domain, a central coiled-coil domain containing a Rho binding site, and a C-terminal pleckstrin homology domain. Here we present the crystal structure of a large section of the central coiled-coil domain of human ROCK I (amino acids 535-700. The structure forms a parallel α-helical coiled-coil dimer that is structurally similar to tropomyosin, an actin filament binding protein. There is an unusual discontinuity in the coiled-coil; three charged residues (E613, R617 and D620 are positioned at what is normally the hydrophobic core of coiled-coil packing. We speculate that this conserved irregularity could function as a hinge that allows ROCK to adopt its autoinhibited conformation.

  18. A set of computationally designed orthogonal antiparallel homodimers that expands the synthetic coiled-coil toolkit.

    Science.gov (United States)

    Negron, Christopher; Keating, Amy E

    2014-11-26

    Molecular engineering of protein assemblies, including the fabrication of nanostructures and synthetic signaling pathways, relies on the availability of modular parts that can be combined to give different structures and functions. Currently, a limited number of well-characterized protein interaction components are available. Coiled-coil interaction modules have been demonstrated to be useful for biomolecular design, and many parallel homodimers and heterodimers are available in the coiled-coil toolkit. In this work, we sought to design a set of orthogonal antiparallel homodimeric coiled coils using a computational approach. There are very few antiparallel homodimers described in the literature, and none have been measured for cross-reactivity. We tested the ability of the distance-dependent statistical potential DFIRE to predict orientation preferences for coiled-coil dimers of known structure. The DFIRE model was then combined with the CLASSY multistate protein design framework to engineer sets of three orthogonal antiparallel homodimeric coiled coils. Experimental measurements confirmed the successful design of three peptides that preferentially formed antiparallel homodimers that, furthermore, did not interact with one additional previously reported antiparallel homodimer. Two designed peptides that formed higher-order structures suggest how future design protocols could be improved. The successful designs represent a significant expansion of the existing protein-interaction toolbox for molecular engineers.

  19. Exploiting Oligo(amido amine) Backbones for the Multivalent Presentation of Coiled-Coil Peptides.

    Science.gov (United States)

    Gerling-Driessen, Ulla I M; Mujkic-Ninnemann, Nina; Ponader, Daniela; Schöne, Daniel; Hartmann, Laura; Koksch, Beate; Gerling-Driessen, U I M; Schöne, D; Koksch, B; Ponader, D; Mujkic-Ninnemann, N; Hartmann, L

    2015-08-10

    The investigation of coiled coil formation for one mono- and two divalent peptide-polymer conjugates is presented. Through the assembly of the full conjugates on solid support, monodisperse sequence-defined conjugates are obtained with defined positions and distances between the peptide side chains along the polymeric backbone. A heteromeric peptide design was chosen, where peptide K is attached to the polymer backbone, and coiled-coil formation is only expected through complexation with the complementary peptide E. Indeed, the monovalent peptide K-polymer conjugate displays rapid coiled-coil formation when mixed with the complementary peptide E sequence. The divalent systems show intramolecular homomeric coiled-coil formation on the polymer backbone despite the peptide design. Interestingly, this intramolecular assembly undergoes a conformational rearrangement by the addition of the complementary peptide E leading to the formation of heteromeric coiled coil-polymer aggregates. The polymer backbone acts as a template bringing the covalently bound peptide strands in close proximity to each other, increasing the local concentration and inducing the otherwise nonfavorable formation of intramolecular helical assemblies.

  20. Routine phasing of coiled-coil protein crystal structures with AMPLE.

    Science.gov (United States)

    Thomas, Jens M H; Keegan, Ronan M; Bibby, Jaclyn; Winn, Martyn D; Mayans, Olga; Rigden, Daniel J

    2015-03-01

    Coiled-coil protein folds are among the most abundant in nature. These folds consist of long wound α-helices and are architecturally simple, but paradoxically their crystallographic structures are notoriously difficult to solve with molecular-replacement techniques. The program AMPLE can solve crystal structures by molecular replacement using ab initio search models in the absence of an existent homologous protein structure. AMPLE has been benchmarked on a large and diverse test set of coiled-coil crystal structures and has been found to solve 80% of all cases. Successes included structures with chain lengths of up to 253 residues and resolutions down to 2.9 Å, considerably extending the limits on size and resolution that are typically tractable by ab initio methodologies. The structures of two macromolecular complexes, one including DNA, were also successfully solved using their coiled-coil components. It is demonstrated that both the ab initio modelling and the use of ensemble search models contribute to the success of AMPLE by comparison with phasing attempts using single structures or ideal polyalanine helices. These successes suggest that molecular replacement with AMPLE should be the method of choice for the crystallo-graphic elucidation of a coiled-coil structure. Furthermore, AMPLE may be able to exploit the presence of a coiled coil in a complex to provide a convenient route for phasing.

  1. Winding mandrel design for the wide cable SSC dipole

    International Nuclear Information System (INIS)

    Morgan, G.H.; Greene, A.; Jochen, G.; Morgillo, A.

    1990-01-01

    The 50 mm coil i.d. SSC dipole magnets use wider cables to give a greater operational margin between quench field and operating field. The cable used for the inner coil has 30 strands of the same size (0.808 mm) instead of 23 and the outer has 36 strands of the same size (0.648 mm) instead of 30 and the cable widths are increased in proportion. Although the coil inner diameter has been increased from 40 mm, the coil ends are noticeably harder to wind. This report describes the computational and experimental effort to design winding mandrels or center posts for the constant-perimeter ends. 1 ref., 2 figs., 2 tabs

  2. Inhibition of the 26S proteasome by peptide mimics of the coiled-coil region of its ATPase subunits.

    Science.gov (United States)

    Inobe, Tomonao; Genmei, Reiko

    Regulation of proteasomal degradation is an indispensable tool for biomedical studies. Thus, there is demand for novel proteasome inhibitors. Proteasomal degradation requires formation of coiled-coil structure by the N-terminal region of ATPase subunits of the proteasome cap. Here we show that peptides that mimic the N-terminal coiled-coil region of ATPase subunits interfere with proteasome function. These results suggest that coiled-coil peptides represent promising new proteasome inhibitors and that N-terminal coiled-coil regions of ATPase subunits are targets for proteasome inhibition. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Magnetic field mapper based on rotating coils

    CERN Document Server

    AUTHOR|(CDS)2087244; Arpaia, Pasquale

    This thesis presents a magnetic field mapper based on rotating coils. The requirements, the architecture, the conceptual design, and the prototype for straight magnets were shown. The proposed system is made up of a rotating coil transducer and a train-like system for longitudinal motion and positioning inside magnet bore. The mapper allows a localized measurement of magnetic fields and the variation of the harmonic multipole content in the magnet ends. The proof-of-principle demonstration and the experimental characterization of the rotating-coil transducer specifically conceived for mapping validated the main objective of satisfying the magnetic measurement needs of the next generation of compact accelerators.

  4. CS model coil experimental log book

    International Nuclear Information System (INIS)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  5. Large magnetic coils for fusion technology

    International Nuclear Information System (INIS)

    Komarek, P.; Ulbricht, A.

    1989-01-01

    This paper reviews the current status of research in this field and outlines future tasks and experiments for the Next European Torus (NET). Research and development work accomplished so far permits generation and safe operation of magnetic fields up to 9 T by means of NbTi coils. Fields up to 11 T are feasible if the coils are cooled with superfluid helium at 1.8 K. The potential of the Nb 3 Sn coils promise achievement of magnetic fields between 12 and 13 T. (MM) [de

  6. Cooling a solar telescope enclosure: plate coil thermal analysis

    Science.gov (United States)

    Gorman, Michael; Galapon, Chriselle; Montijo, Guillermo; Phelps, LeEllen; Murga, Gaizka

    2016-08-01

    The climate of Haleakalā requires the observatories to actively adapt to changing conditions in order to produce the best possible images. Observatories need to be maintained at a temperature closely matching ambient or the images become blurred and unusable. The Daniel K. Inouye Solar Telescope is a unique telescope as it will be active during the day as opposed to the other night-time stellar observatories. This means that it will not only need to constantly match the ever-changing temperature during the day, but also during the night so as not to sub-cool and affect the view field of other telescopes while they are in use. To accomplish this task, plate coil heat exchanger panels will be installed on the DKIST enclosure that are designed to keep the temperature at ambient temperature +0°C/-4°C. To verify the feasibility of this and to validate the design models, a test rig has been installed at the summit of Haleakalā. The project's purpose is to confirm that the plate coil panels are capable of maintaining this temperature throughout all seasons and involved collecting data sets of various variables including pressures, temperatures, coolant flows, solar radiations and wind velocities during typical operating hours. Using MATLAB, a script was written to observe the plate coil's thermal performance. The plate coil did not perform as expected, achieving a surface temperature that was generally 2ºC above ambient temperature. This isn't to say that the plate coil does not work, but the small chiller used for the experiment was undersized resulting in coolant pumped through the plate coil that was not supplied at a low enough temperature. Calculated heat depositions were about 23% lower than that used as the basis of the design for the hillers to be used on the full system, a reasonable agreement given the fact that many simplifying assumptions were used in the models. These were not carried over into the testing. The test rig performance showing a 23% margin

  7. 12 T test module coil (TMC-II) in the cluster test program

    International Nuclear Information System (INIS)

    Ando, T.; Nakajima, H.; Nishi, M.; Okuno, K.; Shimamoto, S.; Tada, E.; Takahashi, Y.; Yasukochi, K.; Yoshida, K.

    1983-01-01

    A 12 T-forced flow cooled test module coil (TMC-II) has been designed as the second step of the cluster test program which is demonstration program of high field toroidal coils in tokamak fusion machine. The TMC-II is a dee shaped coil with a 0.76 m x 0.92 m winding bore, and an average current density in winding is 37.5 A/mm 2 with an operating current of 11.4 kA. A cable-in-conduit type conductor, which consists of 60 strands, is selected for the TMC-II. A strand is composed of multi-filamentary (MF) Nb 3 Sn superconducting material, and copper and aluminum as the stabilizer. A thermal barrier is mounted on the surface of strand to decrease thermal input due to the friction between strands. To obtain the rigidity of the winding, a stainless steel ''Armor'', in which is placed cable-in-conduit conductor by covered by insulator, is welded to ''Armor'' of the next turn. This advanced design has been performed with the strong support of the research and development

  8. Flexible eddy current coil arrays

    International Nuclear Information System (INIS)

    Krampfner, Y.; Johnson, D.P.

    1987-01-01

    A novel approach was devised to overcome certain limitations of conventional eddy current testing. The typical single-element hand-wound probe was replaced with a two dimensional array of spirally wound probe elements deposited on a thin, flexible polyimide substrate. This provides full and reliable coverage of the test area and eliminates the need for scanning. The flexible substrate construction of the array allows the probes to conform to irregular part geometries, such as turbine blades and tubing, thereby eliminating the need for specialized probes for each geometry. Additionally, the batch manufacturing process of the array can yield highly uniform and reproducible coil geometries. The array is driven by a portable computer-based eddy current instrument, smartEDDY/sup TM/, capable of two-frequency operation, and offers a great deal of versatility and flexibility due to its software-based architecture. The array is coupled to the instrument via an 80-switch multiplexer that can be configured to address up to 1600 probes. The individual array elements may be addressed in any desired sequence, as defined by the software

  9. Coil geometry effects on scanning single-coil magnetic induction tomography

    Science.gov (United States)

    Feldkamp, Joe R.; Quirk, Stephen

    2017-09-01

    Alternative coil designs for single coil magnetic induction tomography are considered in this work, with the intention of improving upon the standard design used previously. In particular, we note that the blind spot associated with this coil type, a portion of space along its axis where eddy current generation can be very weak, has an important effect on performance. The seven designs tested here vary considerably in the size of their blind spot. To provide the most discerning test possible, we use laboratory phantoms containing feature dimensions similar to blind spot size. Furthermore, conductivity contrasts are set higher than what would occur naturally in biological systems, which has the effect of weakening eddy current generation at coil locations that straddle the border between high and low conductivity features. Image reconstruction results for the various coils show that coils with smaller blind spots give markedly better performance, though improvements in signal-to-noise ratio could alter that conclusion.

  10. A coil test facility for the cryogenic tests of the JT-60SA TF coils

    International Nuclear Information System (INIS)

    Chantant, M.; Genini, L.; Bayetti, P.; Millet, F.; Wanner, M.; Massaut, V.; Corte, A. Della; Ardelier-Desage, F.; Catherine-Dumont, V.; Dael, A.; Decool, P.; Donati, A.; Duchateau, J.L.; Garibaldi, P.; Girard, S.; Hatchressian, J.C.; Fejoz, P.; Jamotton, P.; Jourdheuil, L.; Juster, F.P.

    2011-01-01

    In the framework of the Broader Approach Activities, the EU will deliver to Japan the 18 superconducting coils, which constitute the JT-60SA Toroidal field magnet. These 18 coils, manufactured by France and Italy, will be cold tested before shipping to Japan. For this purpose, the European Joint Undertaking for ITER, the Development of Fusion Energy ('Fusion for Energy', F4E) and the European Voluntary Contributors are collaborating to design and set-up a coil test facility (CTF) and to perform the acceptance test of the 18 JT-60SA Toroidal Field (TF) coils. The test facility is designed to test one coil at a time at nominal current and cryogenic temperature. The test of the first coil of each manufacturer includes a quench triggered by increasing the temperature. The project is presently in the detailed design phase.

  11. Vacuum chamber eddy current correction coil for the AGS booster

    International Nuclear Information System (INIS)

    Danby, G.; Jackson, J.

    1988-01-01

    This paper reports on the AGS Booster injector that performs a variety of functions. Heavy ion acceleration requires a bakeable, ultra-high vacuum system (VC). Acceleration for intense proton beams requires rapid cycling (B ≤10T/sec). If straight forward heavy walled VC are used, the field perturbations due to eddy currents are large. The state of the art lattice has highly distributed lumped sextupoles capable of substantially correcting the induced field nonlinearity. Nevertheless, for the very highest space charge-intensity limits, it is desirable to have the capability to remove eddy current fields at the source. Correction coils attached to the outside of the VC cancel its current aberrations over the required good field aperture. These can be passively powered by transformer action, using two turn windings around the magnet yoke. Programmed power supplies can also be used. This inexpensive additional correction option uses a three turn per quadrant coil which follows the local contour of the VC. Transverse movements of several mms of the VC will have no beam optical effect since the large field aberrations and their corrections have the same displace coordinates. Experimental and computer studies will be presented, as well as mechanical and electrical design of a simple method of construction

  12. Vacuum chamber eddy current correction coil for the AGS Booster

    International Nuclear Information System (INIS)

    Danby, G.; Jackson, J.

    1988-01-01

    The AGS Booster injector will perform a variety of functions. Heavy ion acceleration requires a bakeable, ultra-high vacuum system (VC). Acceleration for intense proton beams requires rapid cycling (B /preceq/ 10T/sec). If straight forward heavy walled VC are used, the field perturbations due to eddy currents are large. The state of the art lattice has highly distributed lumped sextupoles capable of substantially correcting the induced field nonlinearity. Nevertheless, for the very highest space charge-intensity limits, it is desirable to have the capability to remove eddy current fields at the source. Correction coils attached to the outside of the VC cancel its current aberrations over the required good field aperture. These can be passively powered by transformer action, using two turn windings around the magnet yoke. Programmed power supplies can also be used. This inexpensive additional correction option uses a three turn per quadrant coil which follows the local contour of the VC. Transverse movements of several mms of the VC will have no beam optical effect since the large field aberrations and their corrections have the same displaced coordinates. Experimental and computer studies will be presented, as well as mechanical and electrical design of a simple method of construction. 6 figs

  13. Study of the distributed H-parameter of an anisotropic optical fiber in a multi-layer coil of a fiberoptic gyroscope

    Science.gov (United States)

    Mukhtubaev, A. B.; Aksarin, S. M.; Strigalev, V. E.; Novikov, R. L.

    2017-08-01

    An investigation has been performed on the distributed H-parameter in an anisotropic optical fiber with an elliptical strained shell in a multilayer coil of a fiberoptic gyroscope. Each fiber length is 50 m and there are five layers. Studies have been carried out using three variants of coils. In the first variant, the layers were permeated by epoxy; in the second coil, the layers were permeated with silicon-based material; and, in the third variant, the coils were wound up without impregnation (using dry winding). The different influence of compressive mechanical stresses on the distributed H-parameter of the studied fiber has been observed depending on the variant of coil impregnation.

  14. Development of an Electromagnetic Energy Harvester for Monitoring Wind Turbine Blades

    OpenAIRE

    Joyce, Bryan Steven

    2011-01-01

    Wind turbine blades experience tremendous stresses while in operation. Failure of a blade can damage other components or other wind turbines. This research focuses on developing an electromagnetic energy harvester for powering structural health monitoring (SHM) equipment inside a turbine blade. The harvester consists of a magnet inside a tube with coils outside the tube. The changing orientation of the blade causes the magnet to slide along the tube, inducing a voltage in the coils which ...

  15. Database system for analysing and managing coiled tubing drilling data

    Science.gov (United States)

    Suh, J.; Choi, Y.; Park, H.; Choe, J.

    2009-05-01

    This study present a prototype of database system for analysing and managing petrophysical data from coiled tubing drilling in the oil and gas industry. The characteristics of coiled tubing drilling data from cores were analyzed and categorized according to the whole drilling process and data modeling including object relation diagram, class diagram was carried out to design the schema of effective database system such as the relationships between tables and key index fields to create the relationships. The database system called DrillerGeoDB consists of 22 tables and those are classified with 4 groups such as project information, stratum information, drilling/logging information and operation evaluate information. DrillerGeoDB provide all sort of results of each process with a spreadsheet such as MS-Excel via application of various algorithm of logging theory and statistics function of cost evaluation. This presentation describes the details of the system development and implementation.

  16. The Search-coil Magnetometer for the THOR mission

    Science.gov (United States)

    Sahraoui, Fouad; Jannet, Guillaume; Pinçon, Jean-louis; Mansour, Malik; Chalumeau, Gilles; Chabassière, Michel; Hachemi, Tedjani; Jeandet, Alexis; Henri, Pierre; Le Contel, Olivier; Rezeau, Laurence

    2017-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space that is fully dedicated to plasma turbulence. The search-coil magnetometer (SCM) of THOR is a triaxial dual-band antenna dedicated to measuring the magnetic field fluctuations in the frequency range [1Hz,4kHz] and [1,200]kHz. THOR/SCM has a long heritage from earlier space missions such as Cluster, Themis, MMS, BepiColombo, Taranis, Solar orbiter and Solar Probe. In comparison to those missions, the SCM of THOR has a higher sensitivity level, which makes it capable of measuring very low amplitude magnetic fluctuations, in particular in the solar wind. Those measurements are crucial to address the problem of turbulence and energy dissipation at electron scales, a central goal of the THOR mission.

  17. Functional Analysis of the Bacteriophage T4 Rad50 Homolog (gp46) Coiled-coil Domain.

    Science.gov (United States)

    Barfoot, Tasida; Herdendorf, Timothy J; Behning, Bryanna R; Stohr, Bradley A; Gao, Yang; Kreuzer, Kenneth N; Nelson, Scott W

    2015-09-25

    Rad50 and Mre11 form a complex involved in the detection and processing of DNA double strand breaks. Rad50 contains an anti-parallel coiled-coil with two absolutely conserved cysteine residues at its apex. These cysteine residues serve as a dimerization domain and bind a Zn(2+) cation in a tetrathiolate coordination complex known as the zinc-hook. Mutation of the zinc-hook in bacteriophage T4 is lethal, indicating the ability to bind Zn(2+) is critical for the functioning of the MR complex. In vitro, we found that complex formation between Rad50 and a peptide corresponding to the C-terminal domain of Mre11 enhances the ATPase activity of Rad50, supporting the hypothesis that the coiled-coil is a major conduit for communication between Mre11 and Rad50. We constructed mutations to perturb this domain in the bacteriophage T4 Rad50 homolog. Deletion of the Rad50 coiled-coil and zinc-hook eliminates Mre11 binding and ATPase activation but does not affect its basal activity. Mutation of the zinc-hook or disruption of the coiled-coil does not affect Mre11 or DNA binding, but their activation of Rad50 ATPase activity is abolished. Although these mutants excise a single nucleotide at a normal rate, they lack processivity and have reduced repetitive exonuclease rates. Restricting the mobility of the coiled-coil eliminates ATPase activation and repetitive exonuclease activity, but the ability to support single nucleotide excision is retained. These results suggest that the coiled-coiled domain adopts at least two conformations throughout the ATPase/nuclease cycle, with one conformation supporting enhanced ATPase activity and processivity and the other supporting nucleotide excision. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. MR angiography after coiling of intracranial aneurysms

    NARCIS (Netherlands)

    Schaafsma, J.D.

    2012-01-01

    Introduction Endovascular occlusion with detachable coils has become an alternative treatment to neurosurgical clipping of intracranial aneurysms over the last two decades. Its minimal invasiveness is the most important advantage of this treatment compared to clipping. The disadvantage of occlusion

  19. Superconducting magnet coils protection schemes and apparatus

    International Nuclear Information System (INIS)

    Kuchinski, V.; Bulgakov, S.; Larionov, B.; Mikhailov, N.; Silin, V.

    1995-01-01

    The circuitry of the superconducting coils protection system of the large fusion installations is analyzed. The requirements to the switches and several options of the circuit breakers and making switches with the data of their experimental study are discussed. (orig.)

  20. Fields analysis of TFR 604 copper coils

    International Nuclear Information System (INIS)

    Bourrier, P.; Dubois, C.; Deschamps, P.; Millard, A.

    1979-01-01

    This paper describes the analysis of the toroidal Bitter type coils of TFR-604 fusion device. Electric, magnetic and mechanical fields have been investigated. The major difficulty arises from the quite complicated shape of the structure

  1. Fourier transform-infrared spectroscopy as a diagnostic tool for mosquito coil smoke inhalation toxicity in Swiss Albino mice

    Science.gov (United States)

    Anusha, Chidambaram; Sankar, Renu; Varunkumar, Krishnamoorthy; Sivasindhuja, Gnanasambantham; Ravikumar, Vilwanathan

    2017-12-01

    The goal of this study is to establish Fourier transform-infrared (FTIR) spectroscopy as a diagnostic tool for allethrin-based mosquito coil smoke inhalation induced toxicity in mice. Primarily, we confirmed mosquito coil smoke inhalation toxicity in mice via reduced the body, organ weight and major vital organ tissue morphological structure changes. Furthermore, FTIR spectra was collected from control and mosquito coil smoke inhalation (8 h per day for 30 days) mice various tissues like liver, kidney, lung, heart and brain, to investigate the functional groups and their corresponding biochemical content variations. The FTIR spectra result shown major bio macromolecules such as protein and lipid functional peaks were shifted (decreased) in the mosquito coil smoke inhalation group as compared to control. The drastic peak shift was noticed in the liver, kidney followed by lung and brain. It is therefore concluded that the FTIR spectroscopy can be a successful detection tool in mosquito coil smoke inhalation toxicity.

  2. Umbilical coiling index & the perinatal outcome.

    Science.gov (United States)

    Devaru, Dakshayini; Thusoo, Meghna

    2012-02-01

    To correlate the perinatal outcome by noting the umbilical coiling index. The umbilical cords of the babies born to 100 women, who delivered either vaginally or by lower segment cesarean section, were examined and umbilical coiling index was calculated. There was significant correlation (p value 0.003) between the hypercoiled cords (UCI >90th percentile) and intrauterine growth restriction of the babies. Apgar score at 1 min UCI UCI UCI >10th percentile is associated with intra uterine growth restriction.

  3. Heterogeneous Superconducting Low-Noise Sensing Coils

    Science.gov (United States)

    Hahn, Inseob; Penanen, Konstantin I.; Ho Eom, Byeong

    2008-01-01

    A heterogeneous material construction has been devised for sensing coils of superconducting quantum interference device (SQUID) magnetometers that are subject to a combination of requirements peculiar to some advanced applications, notably including low-field magnetic resonance imaging for medical diagnosis. The requirements in question are the following: The sensing coils must be large enough (in some cases having dimensions of as much as tens of centimeters) to afford adequate sensitivity; The sensing coils must be made electrically superconductive to eliminate Johnson noise (thermally induced noise proportional to electrical resistance); and Although the sensing coils must be cooled to below their superconducting- transition temperatures with sufficient cooling power to overcome moderate ambient radiative heat leakage, they must not be immersed in cryogenic liquid baths. For a given superconducting sensing coil, this combination of requirements can be satisfied by providing a sufficiently thermally conductive link between the coil and a cold source. However, the superconducting coil material is not suitable as such a link because electrically superconductive materials are typically poor thermal conductors. The heterogeneous material construction makes it possible to solve both the electrical- and thermal-conductivity problems. The basic idea is to construct the coil as a skeleton made of a highly thermally conductive material (typically, annealed copper), then coat the skeleton with an electrically superconductive alloy (typically, a lead-tin solder) [see figure]. In operation, the copper skeleton provides the required thermally conductive connection to the cold source, while the electrically superconductive coating material shields against Johnson noise that originates in the copper skeleton.

  4. Coil tests and superconductor code calculations for the stellarator W7-X coils

    Science.gov (United States)

    Baldzuhn, J.; Ehmler, H.; Hoelting, A.; Hertel, K.; Sborchia, C.; Genini, L.; Schild, T.

    2006-07-01

    For the stellarator Wendelstein 7-X, a plasma fusion experiment, the performance of the superconducting coils is tested in a cryogenic test facility. Focus is on the quench behaviour of these coils. Some key data of the coils are given here. The coil quench data, obtained during the tests, are compared to GANDALF code calculations. GANDALF is a one-dimensional finite elements code for the simulation of the quench properties of superconducting CICC cables. Good consistency between measurement and calculation is found for the development of the resistive voltage and temperature increase during the quench.

  5. Magnetic resonance dacryocystography: comparison between conventional surface coils and microscopic coils

    International Nuclear Information System (INIS)

    Abreu Junior, Luiz de; Wolosker, Angela Maria Borri; Borri, Maria Lucia; Galvao Filho, Mario de Melo; Hartmann, Luiz Guilherme de Carvalho; D'Ippolito, Giuseppe; Castro, Claudio Campi de

    2008-01-01

    Objective: Magnetic resonance imaging has been utilized in the evaluation of the lacrimal apparatus with some advantages over conventional dacryocystography. The present study was aimed at acquiring high resolution images utilizing microscopic coils for evaluating typical structures of the lacrimal apparatus as compared with the findings observed with conventional surface coils. Materials and methods: Five asymptomatic volunteers with no history of epiphora were submitted to high-field magnetic resonance imaging with microscopic and conventional surface coils, and STIR sequence after instillation of saline solution. The definition of normal anatomic structures of lacrimal apparatuses was compared utilizing conventional and microscopic surface coils. Based on a consensual scoring system, the mean values for each structure were calculated by two observers. Results: In 90% of cases, higher scores were attributed to images acquired with the microscopic coil. On average, a 1.17 point increase was observed in the scoring of anatomic structures imaged with the microscopic coil. Additionally, a subjective improvement was observed in the signal-to-noise ratio with the microscopic coil. Conclusion: Magnetic resonance dacryocystography with microscopic coils is the appropriate method for evaluating the lacrimal apparatus, providing images with better quality as compared with those acquired with conventional surface coils. (author)

  6. Coiled coil interactions for the targeting of liposomes for nucleic acid delivery.

    Science.gov (United States)

    Oude Blenke, Erik E; van den Dikkenberg, Joep; van Kolck, Bartjan; Kros, Alexander; Mastrobattista, Enrico

    2016-04-28

    Coiled coil interactions are strong protein-protein interactions that are involved in many biological processes, including intracellular trafficking and membrane fusion. A synthetic heterodimeric coiled-coil forming peptide pair, known as E3 (EIAALEK)3 and K3 (KIAALKE)3 was used to functionalize liposomes encapsulating a splice correcting oligonucleotide or siRNA. These peptide-functionalized vesicles are highly stable in solution but start to cluster when vesicles modified with complementary peptides are mixed together, demonstrating that the peptides quickly coil and crosslink the vesicles. When one of the peptides was anchored to the cell membrane using a hydrophobic cholesterol anchor, vesicles functionalized with the complementary peptide could be docked to these cells, whereas non-functionalized cells did not show any vesicle tethering. Although the anchored peptides do not have a downstream signaling pathway, microscopy pictures revealed that after four hours, the majority of the docked vesicles were internalized by endocytosis. Finally, for the first time, it was shown that the coiled coil assembly at the interface between the vesicles and the cell membrane induces active uptake and leads to cytosolic delivery of the nucleic acid cargo. Both the siRNA and the splice correcting oligonucleotide were functionally delivered, resulting respectively in the silencing or recovery of luciferase expression in the appropriate cell lines. These results demonstrate that the docking to the cell by coiled coil interaction can induce active uptake and achieve the successful intracellular delivery of otherwise membrane impermeable nucleic acids in a highly specific manner.

  7. Comparison of the effectiveness of preoperative portal vein embolization in patients with chronic liver disease: Gelfoam versus gelfoam coil

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Wook; Chang, Il Soo; Do, Young Soo; Park, Hong Suk; Park, Kwang Bo; Cho, Sung Ki; Choo, In Wook [Dept. of Radiology, and Cardiac and Vascular Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Choo, Sung Wook [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of)

    2015-05-15

    To compare the effectiveness of portal vein embolization (PVE) performed using gelfoam or a gelfoam-coil combination before major hepatic resection in patients with chronic liver disease. PVE using gelfoam or a gelfoam-coil combination was performed in 37 patients. From April 2003 to September 2007, PVE was performed using gelfoam (n = 17) and a gelfoam-coil combination (n = 20) to induce hypertrophy. Computed tomography volumetry was performed 2-4 weeks after PVE to assess the changes in liver volume. The mean percentage increase in future liver remnant volume was 23.7 +/- 23.7% in the gelfoam group and 36.7 +/- 18.5% in the gelfoam-coil group (p = 0.02). Recanalization was found in 15 gelfoam group patients and 8 gelfoam-coil group patients (p = 0.003). The mean tumor size increased from 4.5 +/- 2.9 cm before PVE to 5.0 +/- 3.5 cm after PVE in the gelfoam group and from 4.3 +/- 2.2 cm before PVE to 4.7 +/- 2.5 cm after PVE in the gelfoam-coil group (p = 0.80). The gelfoam-coil combination was more effective than gelfoam alone for induction of compensatory hypertrophy by PVE in patients with chronic liver disease.

  8. Wind Structure and Wind Loading

    DEFF Research Database (Denmark)

    Brorsen, Michael

    The purpose of this note is to provide a short description of wind, i.e. of the flow in the atmosphere of the Earth and the loading caused by wind on structures. The description comprises: causes to the generation of windhe interaction between wind and the surface of the Earthhe stochastic nature...... of windhe interaction between wind and structures, where it is shown that wind loading depends strongly on this interaction...

  9. Poloidal coils for the Large Helical Device (LHD)

    International Nuclear Information System (INIS)

    Takahata, K.; Satow, T.; Iwamoto, A.

    1996-01-01

    Poloidal coil system of the Large Helical Device (LHD) consists of three pairs of circular solenoids; Inner Vertical (IV), Inner shaping (IS) and Outer Vertical (OV) coils. Forced flow cooling is adopted as a cooling method of the poloidal coils. The conductors of the poloidal coils are Nb-Ti cable-in-conduit types. Each coil consists of eight double-pancake coils, and coolant flows in parallel from the inner turns to the outer turns. A superconducting joint technique is adopted in the joints among the double-pancake coils. Miniaturized joints and severe quality control bring the reduction of error field. (author)

  10. HydroSoft coil versus HydroCoil for endovascular aneurysm occlusion study: A single center experience

    International Nuclear Information System (INIS)

    Guo Xinbin; Fan Yimu; Zhang Jianning

    2011-01-01

    Background and purpose: The HydroCoil Embolic System (HES) was developed to reduce recurrences of aneurysms relative to platinum coils. But the HydroCoil Embolic System was characterized with many limitations. The manufacturer had recognized the challenge and recently a new design of hydrogel-coated coil-HydroSoft has become available in the market as the new generation HydroCoil. We reported our initial experience using HydroSoft coil versus HydroCoil in our center. Methods: 75 aneurysms embolized primarily using HydroSoft Coils from July 2008 to May 2009 were compared with 66 volume- and shape-matched aneurysms treated with HydroCoils from March 2006 to August 2008. Outcome measures included length and number of coils used, contrast volume, and length of hospital stay. During embolization, a stable framework was first established with bare coils, and hydrogel-coated coils were used subsequently to increase the packing density. Follow-up angiographic results 6 months after treatment were evaluated among some of the patients. Results: Successful coil embolization was achieved in all patients. There were no differences in average total coil length used per aneurysm. There were no differences in length of hospital stay and packing density. HydroSoft coils were more suitable using as the finishing or final coil. HydroSoft coil decreased the procedure-related retreated rates, and aneurysm packing was finished with soft, flexible HydroSoft coil and decreased the neck remnant rates. Follow-up angiography in HydroSoft-treated patients at 6 months revealed aneurysm stability without significant residual neck. Conclusions: HydroSoft coil allowed us to deploy coated coils with good packing density. A slight expansion of these coils at the neck can be expected to reduce neck remnant and potentially inhibit recurrence.

  11. Comparative study on current limiting characteristics of flux-lock type SFCL with series or parallel connection of two coils

    International Nuclear Information System (INIS)

    Lim, S.H.

    2008-01-01

    We investigated the current limiting characteristics of the flux-lock type superconducting fault current limiter (SFCL) with series or parallel connection of two coils. These two flux-lock type SFCLs with magnetically coupled two coils have the same operational principle that the fault current can be limited by the magnetic flux generated between two coils of the SFCL when a fault happens. In addition, the inductance ratio and the winding direction of two coils in both the SFCLs are the major design parameters that affect the fault current limiting characteristics of the SFCL. On the other hand, the operational current and the limiting impedance of both the SFCLs under the same design condition have the different tendency, which results from the different winding methods of two coils on an iron core. Therefore, the comparative study for both the SFCLs from the current limiting performance of the SFCL point of view is needed. To compare the current limiting characteristics of both the SFCLs, the operational current and the limiting impedance of the SFCL, which describes the performance of the SFCL, were derived from each SFCL's electrical equivalent circuit. Through the analysis for the fault current limiting experiments of both the SFCLs, the different current limiting characteristics of both the SFCLs were discussed

  12. Characterization of Radiation Induced Current in RF coils of Linac-MR Systems

    Science.gov (United States)

    Burke, Benjamin Lester

    Real-time MR imaging of the cancer patients undergoing external beam radiation treatment represents the next generation in image guided radiotherapy. However, the radio frequency (RF) coil of the MRI is exposed to the pulsed radiation of the linear accelerator in the systems where a medical linear accelerator is integrated with the MRI. This thesis is primarily concerned with the instantaneous effect of pulsed radiation on the RF coils, in particular the Radiation Induced Current (RIC). The RIC results from the charge imbalance created by the ejection of Compton electrons from the thin conductors of the RF coils during the pulsed irradiation. This work spans the initial observations of the RIC in real coils, a detailed characterization of the RIC and finally its impact on the MR image. The first part presented the measurements of the instantaneous RIC in two different MRI RF coils. Some basic characterization of the RIC included the isolation of the RF coil component responsible for RIC, the dependence of RIC on linear accelerator dose rate, and the effect of placing wax buildup on the coil to reduce RIC. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence of the RIC amplitude on dose rate was observed. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. In the second part, a buildup method of RIC removal in planar conductors is tested, a Monte Carlo method of RIC calculation in metal conductors is presented and validated, and the Monte Carlo method is used to examine the effects of magnetic fields on both planar conductor and practical cylindrical coil geometries. The buildup method of RIC removal is effective in planar geometries and in cylindrical coil geometries when the coil conductor is in direct contact with the patient. The presence of air gap between the coil and patient makes this method of RIC removal less effective although placing buildup still reduces the RIC

  13. Versatile fill coils: initial experience as framing coils for oblong aneurysms. A technical case report.

    Science.gov (United States)

    Osanai, Toshiya; Bain, Mark; Hui, Ferdinand K

    2014-01-01

    Coil embolization of oblong aneurysms is difficult because the majority of commercially available coils are manufactured with a helical or spherical tertiary structure. While adopting framing strategies for oblong aneurysms (aspect ratio ≥ 2: 1), traditional coils may be undersized in the long axis but oversized in the short axis, resulting in increased aneurysmal wall stress, risk of re-rupture, and difficulty creating a basket that respects the aneurysmal neck. We review three cases in which versatile filling coils (VFCs) were used as the initial coils for embolization of oblong aneurysms and report coil distribution characteristics and clinical outcomes. Packing density after VFC implantation was assessed using the software AngioSuite-Neuro edition and AngioCalc. a 58-year-old woman experienced a subarachnoid hemorrhage from a ruptured anterior communicating artery aneurysm (7.5 mm × 3.5 mm). A 3-6 mm × 15 cm VFC was selected as the first coil because the flexibility of its wave-loop structure facilitates framing of an irregularly shaped aneurysm. The loop portions of the structures tend to be pressed to the extremes of the aneurysmal sac by the wave component. The VFC was introduced smoothly into the aneurysmal sac without catheter kickback. We were then able to insert detachable filling coils without any adjunctive technique and achieved complete occlusion. Complete occlusion without severe complications was achieved in all three cases in our study. Average packing density after the first coil was 15.63%. VFC coils may have a specific role in framing oblong aneurysms given their complex loop-wave design, allowing spacing of the coils at the dome and neck while keeping sac stress to a minimum.

  14. Structural Correlation of the Neck Coil with the Coiled-coil (CC1)-Forkhead-associated (FHA) Tandem for Active Kinesin-3 KIF13A.

    Science.gov (United States)

    Ren, Jinqi; Huo, Lin; Wang, Wenjuan; Zhang, Yong; Li, Wei; Lou, Jizhong; Xu, Tao; Feng, Wei

    2016-02-12

    Processive kinesin motors often contain a coiled-coil neck that controls the directionality and processivity. However, the neck coil (NC) of kinesin-3 is too short to form a stable coiled-coil dimer. Here, we found that the coiled-coil (CC1)-forkhead-associated (FHA) tandem (that is connected to NC by Pro-390) of kinesin-3 KIF13A assembles as an extended dimer. With the removal of Pro-390, the NC-CC1 tandem of KIF13A unexpectedly forms a continuous coiled-coil dimer that can be well aligned into the CC1-FHA dimer. The reverse introduction of Pro-390 breaks the NC-CC1 coiled-coil dimer but provides the intrinsic flexibility to couple NC with the CC1-FHA tandem. Mutations of either NC, CC1, or the FHA domain all significantly impaired the motor activity. Thus, the three elements within the NC-CC1-FHA tandem of KIF13A are structurally interrelated to form a stable dimer for activating the motor. This work also provides the first direct structural evidence to support the formation of a coiled-coil neck by the short characteristic neck domain of kinesin-3. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Structural Correlation of the Neck Coil with the Coiled-coil (CC1)-Forkhead-associated (FHA) Tandem for Active Kinesin-3 KIF13A*

    Science.gov (United States)

    Ren, Jinqi; Huo, Lin; Wang, Wenjuan; Zhang, Yong; Li, Wei; Lou, Jizhong; Xu, Tao; Feng, Wei

    2016-01-01

    Processive kinesin motors often contain a coiled-coil neck that controls the directionality and processivity. However, the neck coil (NC) of kinesin-3 is too short to form a stable coiled-coil dimer. Here, we found that the coiled-coil (CC1)-forkhead-associated (FHA) tandem (that is connected to NC by Pro-390) of kinesin-3 KIF13A assembles as an extended dimer. With the removal of Pro-390, the NC-CC1 tandem of KIF13A unexpectedly forms a continuous coiled-coil dimer that can be well aligned into the CC1-FHA dimer. The reverse introduction of Pro-390 breaks the NC-CC1 coiled-coil dimer but provides the intrinsic flexibility to couple NC with the CC1-FHA tandem. Mutations of either NC, CC1, or the FHA domain all significantly impaired the motor activity. Thus, the three elements within the NC-CC1-FHA tandem of KIF13A are structurally interrelated to form a stable dimer for activating the motor. This work also provides the first direct structural evidence to support the formation of a coiled-coil neck by the short characteristic neck domain of kinesin-3. PMID:26680000

  16. Byers Auto Group: A Case Study Into The Economics, Zoning, and Overall Process of Installing Small Wind Turbines at Two Automotive Dealerships in Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Oteri, F.; Sinclair, K.

    2011-11-01

    This paper provides the talking points about a case study on the installation of a $600,000 small wind project, the installation process, estimated annual energy production and percentage of energy needs met by the turbines.

  17. Mechanical attachment of the conductor ends in the ITER poloidal field coils

    International Nuclear Information System (INIS)

    Bessette, D.; Decool, P.

    2003-01-01

    The ITER poloidal field (PF) coils are wound from a large cable-in-conduit-conductor, with a stainless steel (SS) jacket. Tapered bonded tails, consisting of shaped steel profiles welded to the conductor ends, are used in these PF coils to mechanically attach the conductor ends to the winding pack. Their main function is to transfer the tensile force from the end of the outermost turn to the adjacent turns by shear through an appropriate thickness of insulating material (glass epoxy). These tails are embedded in the winding pack thus avoiding any local protrusion. Similar tapered bonded tails have been extensively used in large copper coils. However, compared with a standard copper conductor, the tensile force to be transferred to the winding pack is larger in the ITER PF conductor because of the higher tensile stress experienced by the SS jacket (average tensile stress up to 200 MPa). This led to a new hollow tail design capable of transferring the large tensile force carried by the PF coil conductors over a length in the range 600-650 mm. Hollow tails, as opposed to solid tails, provide a larger bonded perimeter for the same effective tail cross section, which also contributes to limiting the peak shear stress in the insulation. As a first step, the geometry of the tail has been optimised through a 1-D analytical straight model that solves the force balance between shear in the insulation and tension in the tail along its length. In a second step, a FEA (finite element analysis) of the most promising configuration has been performed in order to validate the design

  18. Comparison of surface coil and knee coil for evaluation of the patellar cartilage by MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Steen, M. van den; Maeseneer, M. de E-mail: midema@belgacom.net; Hoste, M.; Vanderdood, K.; Ridder, F. de; Osteaux, M

    2003-07-01

    Purpose: The aim of this work was to compare the knee coil and the surface coil for the visualisation of the patellar cartilage. Materials and methods: In 28 patients (17 women, 11 men) with an average age of 40 years (range 14-76) with knee pain MR was performed. Transverse images were obtained using a fast spin echo proton density weighted sequence on a Philips Gyroscan Intera 1.5 T clinical system. Transverse images were obtained at the level of the patellar cartilage using both the surface and the knee coil. All images were evaluated by consensus of two radiologists. They evaluated a number of quality criteria on a 4-point scale. Criteria for artefacts were also graded on a 4-point scale. Results: For the visualisation of fluid there was no significant difference between the knee coil and the surface coil (P=0.021). For all other criteria regarding image quality and presence of imaging artefacts there was a significant difference between both coils (P<0.001) with the surface coil obtaining the better result. Conclusion: The use of the surface coil in the visualisation of the patellar cartilage can be recommended at knee MR.

  19. Immunogenicity of coiled-coil based drug-free macromolecular therapeutics

    Czech Academy of Sciences Publication Activity Database

    Kverka, Miloslav; Hartley, J.M.; Chu, T.W.; Yang, J.; Heidchen, R.; Kopeček, J.

    2014-01-01

    Roč. 35, č. 2 (2014), s. 5886-5896 ISSN 1616-0177 R&D Projects: GA MŠk(CZ) EE2.3.30.0003 Grant - others:NIH(US) GM095606 Institutional support: RVO:61388971 Keywords : coiled-coil * enantiomers * HPMA copolymer Subject RIV: EC - Immunology

  20. The influence of fusion sequences on the thermal stabilities of coiled-coil proteins

    Czech Academy of Sciences Publication Activity Database

    Xu, C.; Joss, L.; Wang, C.; Pechar, Michal; Kopeček, J.

    2002-01-01

    Roč. 2, č. 8 (2002), s. 395-401 ISSN 1616-5187 R&D Projects: GA AV ČR KSK4055109 Grant - others:GA-(US) CA88047 Keywords : coiled -coil * fusion sequence * oligomers Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.792, year: 2002

  1. Additional coiling of previously coiled cerebral aneurysms : Clinical and angiographic results

    NARCIS (Netherlands)

    Slob, MJ; Sluzewski, M; van Rooij, WJ; Roks, G; Rinkel, GJE

    BACKGROUND AND PURPOSE: Some cerebral aneurysms that have been coiled reopen over time and additional treatment should be considered to reduce the risk of recurrent hemorrhage. Our purpose was to assess procedural complications and angiographic results of additional coiling in patients with

  2. Advanced approaches for the characterization of a de novo designed antiparallel coiled coil peptide

    NARCIS (Netherlands)

    Pagel, K; Seeger, K; Seiwert, B; Villa, Alessandra; Mark, AE; Berger, S; Koksch, B

    2005-01-01

    We report here an advanced approach for the characterization of the folding pattern of a de novo designed antiparallel coiled coil peptide by high-resolution methods. Incorporation of two fluorescence labels at the C- and N-terminus of the peptide chain as well as modi. cation of two hydrophobic

  3. Associative diblock copolymers of poly(ethylene glycol) and coiled-coil peptides

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Kopečková, P.; Joss, L.; Kopeček, J.

    2002-01-01

    Roč. 2, č. 5 (2002), s. 199-206 ISSN 1616-5187 R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : coiled -coil peptides * diblock copolymers * poly(ethylene glycol) Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.792, year: 2002

  4. Structural Stability of the Coiled-Coil Domain of Tumor Susceptibility Gene (TSG)-101.

    Science.gov (United States)

    White, Jordan T; Toptygin, Dmitri; Cohen, Randy; Murphy, Natalie; Hilser, Vincent J

    2017-09-05

    The tumor susceptibility gene-101 coiled coil domain (TSG101cc) is an integral component of the endosomal maturation machinery and cytokinesis, and also interacts with several transcription factors. The TSG101cc has been crystallized as a homotetramer but is known to interact with two of its binding partners as a heterotrimer. To investigate this apparent discrepancy, we examined the solution thermodynamics of the TSG101cc. Here, we use circular dichroism, differential scanning calorimetry, analytical ultracentrifugation, fluorescence, and structural thermodynamic analysis to investigate the structural stability and the unfolding of the TSG101cc. We demonstrate that TSG101cc exists in solution primarily as a tetramer, which unfolds in a two-state manner. Surprisingly, no homodimeric or homotrimeric species were detected. Structural thermodynamic analysis of the homotetrameric structure and comparison with known oligomeric coiled-coils suggests that the TSG101cc homotetramer is comparatively unstable on a per residue basis. Furthermore, the homotrimeric coiled-coil is predicted to be much less stable than the functional heterotrimeric coiled-coil in the endosomal sorting complex required for transport 1 (ESCRT1). These results support a model whereby the tetramer-monomer equilibrium of TSG101 serves as the cellular reservoir of TSG101, which is effectively outcompeted when its binding partners are present and the heteroternary complex can form.

  5. Coiled-Coil Domains of SUN Proteins as Intrinsic Dynamic Regulators.

    Science.gov (United States)

    Nie, Si; Ke, Huimin; Gao, Feng; Ren, Jinqi; Wang, Mingzhu; Huo, Lin; Gong, Weimin; Feng, Wei

    2016-01-05

    SUN proteins are the core components of LINC complexes that span across the nuclear envelope for nuclear positioning and migration. SUN proteins contain at least one predicted coiled-coil domain preceding the SUN domain. Here, we found that the two coiled-coil domains (CC1 and CC2) of SUN2 exhibit distinct oligomeric states. CC2 is a monomer in solution. The structure of the CC2-SUN monomer revealed that CC2 unexpectedly folds as a three-helix bundle that interacts with the SUN domain and locks it in an inactive conformation. In contrast, CC1 is a trimer. The structure of the CC1 trimer demonstrated that CC1 is an imperfect coiled coil for the trimerization and activation of the SUN domain. Modulations of CC1 and CC2 dictate different oligomeric states of CC1-CC2-SUN, which is essential for LINC complex formation. Thus, the two coiled-coil domains of SUN2 act as the intrinsic dynamic regulators for controlling the SUN domain activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The tripartite motif coiled-coil is an elongated antiparallel hairpin dimer

    Science.gov (United States)

    Sanchez, Jacint G.; Okreglicka, Katarzyna; Chandrasekaran, Viswanathan; Welker, Jordan M.; Sundquist, Wesley I.; Pornillos, Owen

    2014-01-01

    Tripartite motif (TRIM) proteins make up a large family of coiled-coil-containing RING E3 ligases that function in many cellular processes, particularly innate antiviral response pathways. Both dimerization and higher-order assembly are important elements of TRIM protein function, but the atomic details of TRIM tertiary and quaternary structure have not been fully understood. Here, we present crystallographic and biochemical analyses of the TRIM coiled-coil and show that TRIM proteins dimerize by forming interdigitating antiparallel helical hairpins that position the N-terminal catalytic RING domains at opposite ends of the dimer and the C-terminal substrate-binding domains at the center. The dimer core comprises an antiparallel coiled-coil with a distinctive, symmetric pattern of flanking heptad and central hendecad repeats that appear to be conserved across the entire TRIM family. Our studies reveal how the coiled-coil organizes TRIM25 to polyubiquitylate the RIG-I/viral RNA recognition complex and how dimers of the TRIM5α protein are arranged within hexagonal arrays that recognize the HIV-1 capsid lattice and restrict retroviral replication. PMID:24550273

  7. Golgi coiled-coil proteins contain multiple binding sites for Rab family G proteins

    NARCIS (Netherlands)

    Sinka, Rita; Gillingham, Alison K.; Kondylis, Vangelis; Munro, Sean

    2008-01-01

    Vesicles and other carriers destined for the Golgi apparatus must be guided to the correct cisternae. Golgins, long coiled-coil proteins that localize to particular Golgi subdomains via their C termini, are candidate regulators of vesicle sorting. In this study, we report that the GRIP domain

  8. Coiled versus straight peritoneal dialysis catheters: a randomized controlled trial and meta-analysis.

    Science.gov (United States)

    Xie, Jingyuan; Kiryluk, Krzysztof; Ren, Hong; Zhu, Ping; Huang, Xiaomin; Shen, Pingyan; Xu, Tian; Chen, Xiaonong; Chen, Nan

    2011-12-01

    Variations in peritoneal dialysis catheter design include differences in numbers of cuffs, shapes of subcutaneous paths (swan neck vs Tenckhoff), and shapes of intra-abdominal segments (straight vs coiled). The relative benefits of these designs have not been studied adequately. The objective of this study is to compare the clinical outcomes of coiled- versus straight-end swan neck peritoneal dialysis catheters. Prospective randomized controlled trial (RCT); results were meta-analyzed with other RCTs of coiled versus straight catheters. 80 consecutive continuous ambulatory peritoneal dialysis patients were enrolled in the RCT. The meta-analysis considers data for 242 patients with coiled and 251 patients with straight catheters. Patients were randomly assigned to a coiled-end swan neck catheter (n = 40) or a straight-end swan neck catheter (n = 40) group. Catheter tip migration with dysfunction (primary outcome) and catheter failure, catheter-related infection, technique failure, and all-cause mortality (secondary outcomes). The primary outcome occurred in 18 patients in the coiled group and 9 in the straight group. This difference was not statistically significant (HR, 1.96; 95% CI, 0.88-4.37; P = 0.09). Although rates of early (coiled design with increased risk of late (>8 weeks) catheter tip migration (HR, 6.43; 95% CI, 1.45-28.6; P = 0.005). The increased risk of overall catheter failure in the coiled group was not statistically significant (P = 0.06). In the meta-analysis, coiled catheters were associated significantly with increased risk of catheter tip migration (based on 4 trials: RR, 2.08; 95% CI, 1.30-3.33; P = 0.002). Single-center open-label experimental study powered to detect differences in only the most common complication of catheter tip migration with dysfunction. Our RCT examines only swan neck catheters, whereas the meta-analysis considers both swan neck and Tenckhoff designs. Although we were unable to show statistically significant differences

  9. The Nup62 Coiled-Coil Motif Provides Plasticity for Triple-Helix Bundle Formation.

    Science.gov (United States)

    Dewangan, Pravin S; Sonawane, Parshuram J; Chouksey, Ankita R; Chauhan, Radha

    2017-06-06

    The central transport channel of the vertebrate nuclear pore complex (NPC) consists of nucleoporins: Nup62, Nup54, and Nup58. The coiled-coil domains in α-helical regions of these nucleoporins are thought to be crucial for several protein-protein interactions in the NPC subcomplexes. In this study, we determined the crystal structure of the coiled-coil domain of rat Nup62 fragment (residues 362-425) to 2.4 Å resolution. The crystal structure shows the conserved coiled-coil domain as a parallel three-helix bundle for the Nup62(362-425) fragment. On the basis of our size exclusion chromatography coupled to multiangle light scattering analysis and glutaraldehyde cross-linking experiments, we conclude that the Nup62(362-425) fragment displays dynamic behavior in solution and can also exist in either homodimeric or homotrimeric states. Our comparative analysis of the rat Nup62(362-425) homotrimeric structure with previously reported heterotrimeric structures [rat Nup62(362-425)·Nup54(346-407) and Xenopus Nup62(358-485)·Nup54(315-450)·Nup58(283-406) complexes] demonstrates the structural basis for parallel triple-helix bundle formation for Nup62 with different partners. Moreover, we show that the coiled-coil domain of Nup62 is sufficient for interaction with the coiled-coil domain of rat Exo70, a protein in an exocyst complex. On the basis of these observations, we suggest the plausible chain replacement mechanism that yields to diverse protein assemblies with Nup62. In summary, the coiled-coil motif present in Nup62 imparts the ability to form a homotrimer and heterotrimers either with Nup54 or with Nup54-Nup58 within the NPCs as well as with Exo70 beyond the NPCs. These complexes of Nup62 suggest the crucial role of the coiled-coil motifs in providing plasticity to various modular assemblies.

  10. Structural analysis (Siemens) of the Euratom coil for the large coil task

    International Nuclear Information System (INIS)

    Maurer, A.

    1981-01-01

    The structural analysis of coil and casing of large superconducting magnets is essential to ensure the safety in the design and is important for the concept of even larger magnet units in future projects. For the Large Coil Task calculations are performed by the finite element computer code NASTRAN to obtain the stress on the various structural parts under thermal and magnetic loads. The mechanical behavior of the coil and casing under normal as well as alternative load conditions is discussed. Plots demonstrate the state of deformation belonging to the single structure parts. The results for the components of normal and shear stresses in the coil as well as for the equivalent stresses in the casing are summarized. The finite element model used is presented. The assumptions relating to the material properties, the force transmitted between coil and casing, the loading conditions, and the boundary conditions are discussed. 2 refs

  11. Coil in coil - components for the high voltage superconducting resistive current limiter CULT 110

    Science.gov (United States)

    Elschner, S.; Stemmle, M.; Breuer, F.; Walter, H.; Frohne, C.; Noe, M.; Bock, J.

    2008-02-01

    The German government (BMBF/VDI) funded project CULT 110 is presently the largest European current limiter project and aims at the development of a one-phase resistive limiter for the voltage level of 110 kV. The contribution presents the actual state of development of the superconducting components. As in the successful predecessor project CURL 10 these are made of melt cast processed BSCCO 2212 bulk material, however monofilar instead of bifilar coils are used. The electrical protection concept is based on a normal conducting coil arranged around a superconducting coil and connected in parallel. Simultaneously this coil serves as an electrical bypass and, under fault conditions, generates a magnetic field for quench homogenisation. Since no continuously connected shunt is needed, a much higher voltage during faults can be applied. The rules for an optimum superconductor and coil design are given and the viability of the whole concept is demonstrated by both, experiment and numerical simulation.

  12. Molecular dynamics studies of PEGylated α-helical coiled coils and their self-assembled micelles.

    Science.gov (United States)

    Woo, Sun Young; Lee, Hwankyu

    2014-07-29

    We performed coarse-grained (CG) molecular dynamics simulations of trimeric α-helical coiled coils grafted with poly(ethylene glycol) (PEG) of different sizes and conjugate positions and the self-assembled micelle of amphiphilic trimers. The CG model for the trimeric coiled coil is verified by comparing the α-helical structure and interhelical distance with those calculated from all-atom simulations. In CG simulations of PEGylated trimers, the end-to-end distances and radii of gyration of PEGs grafted to the sides of peptides become shorter than those of free PEGs in water, which agrees with experiments. This shorter size of the grafted PEGs is also confirmed by calculating the thickness of the PEG layer, which is less than the size of the mushroom. These indicate the adsorption of PEG chains onto coiled coils since hydrophobic residues in the exterior sites of coiled coils tend to be less exposed to water and thus interact with PEGs, leading to the compact conformation of adsorbed PEGs. Simulations of the self-assembly of amphiphilic trimers show that the randomly distributed trimers self-assemble to micelles. The outer radius and hydrodynamic radius of the micelle, which were calculated respectively from radial densities and diffusion coefficients, are ∼7 nm, in agreement with the experimental value of ∼7.5 nm, while the aggregation number of amphiphilic molecules per micelle is lower than the experimentally proposed value. These simulations predict the experimentally measured size of PEGs grafted to the trimeric coiled coils and their self-assembled amphiphilic micelles and suggest that the aggregation number of the micelle may be lower, which needs to be confirmed by experiments.

  13. Automated de novo phasing and model building of coiled-coil proteins.

    Science.gov (United States)

    Rämisch, Sebastian; Lizatović, Robert; André, Ingemar

    2015-03-01

    Models generated by de novo structure prediction can be very useful starting points for molecular replacement for systems where suitable structural homologues cannot be readily identified. Protein-protein complexes and de novo-designed proteins are examples of systems that can be challenging to phase. In this study, the potential of de novo models of protein complexes for use as starting points for molecular replacement is investigated. The approach is demonstrated using homomeric coiled-coil proteins, which are excellent model systems for oligomeric systems. Despite the stereotypical fold of coiled coils, initial phase estimation can be difficult and many structures have to be solved with experimental phasing. A method was developed for automatic structure determination of homomeric coiled coils from X-ray diffraction data. In a benchmark set of 24 coiled coils, ranging from dimers to pentamers with resolutions down to 2.5 Å, 22 systems were automatically solved, 11 of which had previously been solved by experimental phasing. The generated models contained 71-103% of the residues present in the deposited structures, had the correct sequence and had free R values that deviated on average by 0.01 from those of the respective reference structures. The electron-density maps were of sufficient quality that only minor manual editing was necessary to produce final structures. The method, named CCsolve, combines methods for de novo structure prediction, initial phase estimation and automated model building into one pipeline. CCsolve is robust against errors in the initial models and can readily be modified to make use of alternative crystallographic software. The results demonstrate the feasibility of de novo phasing of protein-protein complexes, an approach that could also be employed for other small systems beyond coiled coils.

  14. Modulation of elasticity in functionally distinct domains of the tropomyosin coiled-coil.

    Science.gov (United States)

    Lakkaraju, Sirish Kaushik; Hwang, Wonmuk

    2009-03-01

    Alpha-helical coiled-coils are common protein structural motifs. Whereas vast information is available regarding their structure, folding, and stability, far less is known about their elastic properties, even though they play mechanical roles in many cases such as tropomyosin in muscle contraction or neck stalks of kinesin or myosin motor proteins. Using computer simulations, we characterized elastic properties of coiled-coils, either globally or locally. Global bending stiffness of standard leucine zipper coiled-coils was calculated using normal mode analysis. Mutations in hydrophobic residues involved in the knob-into-hole interface between the two alpha-helices affect elasticity significantly, whereas charged side chains forming inter-helical salt bridges do not. This suggests that coiled-coils with less regular heptad periodicity may have regional variations in flexibility. We show this by the flexibility map of tropomyosin, which was constructed by a local fluctuation analysis. Overall, flexibility varies by more than twofold and increases towards the C-terminal region of the molecule. Describing the coiled-coil as a twisted tape, it is generally more flexible in the splay bending than in the bending of the broad face. Actin binding sites in alpha zones show local rigidity minima. Broken core regions due to acidic residues at the hydrophobic face such as the Asp137 and the Glu218 are found to be the most labile with moduli for splay and broad face bending as 70 nm and 116 nm respectively. Such variation in flexibility could be relevant to the tropomyosin function, especially for moving across the non-uniform surface of F-actin to regulate myosin binding.

  15. Materials and techniques for coiling of cerebral aneurysms: how much scientific evidence do we have?

    International Nuclear Information System (INIS)

    Kurre, W.; Berkefeld, J.

    2008-01-01

    Since coils were approved for aneurysm treatment, materials and techniques developed rapidly. It still remains an open question whether one material or method is superior. This article reviews the literature on various coil types and treatment approaches assessing the scientific evidence of its use. Studies on aneurysm treatment with Guglielmi detachable platinum coils, bioactive coils, hydrogel coated coils, and complex designs as well as balloon- and stent-assisted techniques were retrieved by a PubMed database search from 1990 until May 2008. Data were analyzed in terms of aneurysm occlusion, permanent morbidity and mortality, recanalization, and retreatment. We also assessed the level of evidence of the published studies. Only the International Subarachnoid Aneurysm Trial provides level I evidence proving the superiority of endovascular over surgical therapy in ruptured aneurysms. Randomized trials comparing bioactive or hydrogel coated devices with bare coils are ongoing. Other studies were based on registries or case series mainly conducted without control groups. Morbidity, mortality, and initial occlusion rates appear similar for all devices. No clear evidence exists for the superiority of bioactive- or hydrocoils regarding long-term stability. It remains ambiguous whether morbidity and mortality rises with the use of balloons and stents. There is no evidence that routine use of balloons improves treatment durability. Mid-term results of stent-assisted coiling of complex aneurysms appear favorable. There is a lack of studies with a high level of evidence comparing different coiling materials and techniques. Case series and registries were not able to prove the superiority of any device or method. (orig.)

  16. Coil development for W VII-X

    International Nuclear Information System (INIS)

    Kisslinger, J.

    1988-01-01

    Starting from a closed vacuum flux surface near the edge and using the NESCOIL code, current distributions on various toroidal surfaces are obtained. The toroidal surfaces are optimized by varying the coefficients which describe the torus topology, and by restricting the number of coefficients for the potential distribution. Configuration HS4-12 with 4 field periods has 12 coils per field period, and that with 5 periods has 10 or 12 coils per period at an average coil aspect ratio of 5. Aspect ratio of the largest flux surfaces is 10. For Helias configurations with 5 field periods compared to those with 4 field periods, higher beta values are predicted. Keeping the coil aspect ratio constant the configuration with 5 field periods has coils with lower minimum curvature radius and a larger lateral excursion. They also have reduced distance between wall and plasma. To improve the geometrical tightness with 5 field periods an increase of the major radius from 5 to 6.5m and a reduction of Bo from 4 to 3T (which allows an increase of current density from 40 to 50 MA/m 2 ) is proposed

  17. Distal biceps rupture: the coil sign.

    Science.gov (United States)

    Austin, Luke; Pepe, Matt; VanBeek, Corinne; Tjoumakaris, Fotios

    2014-06-01

    Delayed repair of the distal biceps brachii tendon can lead to the formation of scar tissue and coiling of the tendon. Dissection of the scar tissue and unraveling of the tendon may allow for anatomic repair to the radial tuberosity. A 50-year-old man had a distal biceps brachii tendon tear with an intact lacertus fibrosis. Surgery was performed 22 days after injury. On inspection, the distal biceps tendon was coiled, encased in scar tissue, and unable to be reduced to the radial tuberosity. Dissection of the scar tissue and unraveling of the tendon provided additional length, allowing anatomic repair. Postoperatively, the patient regained full range of motion and strength and returned to work without restrictions. After a distal biceps brachii tear in which the lacertus fibrosis remains intact, the coiled tendon may become enveloped in a sheath of scar tissue. Dissection of the "pseudosheath" unveils the native tendon and allows reduction to the radial tuberosity. Cadaveric analysis shows that the pseudosheath may conceal 6 cm of coiled tendon. When the lacertus fibrosis remains intact after distal biceps tendon rupture, the tethered tendon stump may coil, become encased in scar tissue, and resemble the native tendon. Failure to identify the native tendon could result in the loss of 6 cm of tendon. Copyright 2014, SLACK Incorporated.

  18. Extrap with iron-cored coils

    International Nuclear Information System (INIS)

    Lehnert, B.

    1985-05-01

    In Extrap configurations there is a high average beta value with respect to the plasma confinement volume. The externally imposed magnetic field which is required for stabilization therefore comes out to have a rather moderate strength, even under expected reactor conditions. As a consequence, this field can be generated not only by conventional external conductor arrangements, but also by iron-cored coils being operated below the saturation limit. A proposal for such iron-cored coil systems is presented in this paper. As compared to conventional conductors, this has the advantage of localizing the magnetic energy of the externally imposed magnetic field mainly to the discharge vessel and the plasma volume, thereby increasing the engineering beta value substantially. Also the problems of the coil stresses and of irradiation of the coils appear to become simplified, as well as replacement of the coil system. A main limitation of this proposal is due to combination of iron core saturation with the required stabilization effect from an ion Larmor radius of sufficient relative magnitude. This limitaion requires further investigation, especially in the full-scale reactor case. Also the modifications of the field geometry by iron core shaping needs further analysis. (Author)

  19. Prediction of shape diameter undergoing coil embolization of saccular intracranial aneurysm treatment using a hybrid decision support system

    International Nuclear Information System (INIS)

    Owasirikul, Wiwat; Tantivatana, Jaturon; Gansawat, Duangrat; Auethavekiat, Supatana

    2013-01-01

    The purpose of the study was to design a hybrid decision support system (HDSS) that could simulate the embolized coil selection pattern of the radiologists in aneurysms treatment. As the longest available length of the coils should be used in most cases, therefore only the shape diameter (SD) selection was modeled and varied. Ninety-eight aneurysms successfully treated by a radiologist with coil embolization were divided into two groups (86 for training and 12 randomly selected for validating). Eight aneurysms treated by another radiologist were also used to cross validate the proposed HDSS. The HDSS was developed using the classification and the linear regression methods (LRM). The dome and the width of an aneurysm were used as the system inputs. The system outputs were the SDs of the first three coils indexed according to the insertion order. The HDSS that consisted of Bagging classification and LRM achieved the highest accuracy for all cases. The errors were within 1 mm for the SD selection of the first two coils. For the third coil, the SD selection within 1 mm bound had 80 % accuracy. The experimental results indicated the feasibility of using the HDSS as the guidance for selecting the SDs of the first two coils. The selection of the third coil required more training data for the rarely used SD. Moreover, the cross validation with another radiologist showed the feasibility of using the proposed HDSS as the guidance, however further validation with more data is recommended.

  20. Fabrication of the KSTAR toroidal field coil structure

    International Nuclear Information System (INIS)

    Choi, C.H.; Sa, J.W.; Park, H.K.; Hong, K.H.; Shin, H.; Kim, H.T.; Bak, J.S.; Lee, G.S.; Kwak, J.H.; Moon, H.G.; Yoon, H.H.; Lee, J.W.; Lee, S.K.; Song, J.Y.; Nam, K.M.; Byun, S.E.; Kim, H.C.; Ha, E.T.; Ahn, H.J.; Kim, D.S.; Lee, J.S.; Park, K.H.; Hong, C.D.

    2005-01-01

    The KSTAR toroidal field (TF) coil structure is under fabrication upon completion of engineering design and prototype construction. The prototype TF coil structure has been fabricated within allowable tolerances. Encasing of the prototype TF coil (TF00) in the prototype structure has been carried out through major processes involving a coil encasing, an enclosing weld, a vacuum pressure impregnation, and an outer surface machining. During the enclosing weld of the TF00 coil structure, we have measured temperatures and stresses on the coil surface. Assembly test had been performed with the TF00 coil structure. We have chosen Type 316LN as material of the TF coil structure. We used the narrow-gap TIG welding method. Doosan Heavy Industries and Construction Company (DHI) will complete the fabrication of the TF coil structure in Feb. 2006. (author)

  1. Improving Coil Designs for the HSX Stellarator with FOCUS

    Science.gov (United States)

    Kruger, Thomas; Zhu, Caoxiang; Bader, Aaron; Singh, Luquant; Anderson, David

    2017-10-01

    We use the FOCUS code to generate improved coil sets for the HSX stellarator. FOCUS produces curves in 3D space to best reproduce a target plasma equilibrium. Unlike similar codes, the curves in FOCUS are not constrained to lie on a user-defined 2D surface. Therefore FOCUS can inherently solve problems such as determining the optimum coil-plasma distance for a given equilibrium. By adjusting the relative weights between a) the match to the plasma boundary, and b) the average coil length. We present the results from FOCUS where we attempt to improve the coil set by moving coils further away to reduce coil ripple, decreasing the number of coils to improve accessibility, and better matching the target plasma surface. We also present results of alternative coil designs with helical and saddle coils. Work supported by the US DOE under Grant DE-FG02-93ER54222 and UW Sorden account 233PRJ65ZM.

  2. Assisted coiling of saccular wide-necked unruptured intracranial aneurysms: stent versus balloon.

    Science.gov (United States)

    Consoli, Arturo; Vignoli, Chiara; Renieri, Leonardo; Rosi, Andrea; Chiarotti, Ivano; Nappini, Sergio; Limbucci, Nicola; Mangiafico, Salvatore

    2016-01-01

    Assisted coiling with stents or balloons enables a higher percentage of complete occlusions of saccular unruptured intracranial aneurysms to be achieved with a reasonable complication rate. The aim of this study was to compare stent-assisted coiling and the balloon remodeling technique in terms of efficacy, stability, and safety for the treatment of comparable unruptured saccular intracranial aneurysms. 268 patients with 286 saccular unruptured wide-necked intracranial aneurysms were treated at our institution with stent- or balloon-assisted coiling and retrospectively reviewed. Statistical analysis was performed to assess significant differences between the two groups. The rate of complete occlusion at the end of the procedure was higher with stent-assisted coiling than with balloon-assisted coiling (86.8% vs 78%) and the same results were also observed after 6 months (92.1% vs 77.6%; p=0.05). About 50% of major recurrences occurred in large to giant aneurysms (p<0.001). The overall complication rate was similar in the stent-assisted and balloon-assisted groups (10.3% vs 9.3%). Independently of the technique, a higher complication rate was observed with bifurcational aneurysms, particularly in the middle cerebral artery (p=0.016). Stent-assisted coiling achieved better results in terms of complete occlusion and stability than balloon-assisted coiling with a lower rate of recurrence without being associated with a higher risk of intraprocedural complications. Bifurcational and large to giant aneurysms were associated with higher complication rates and higher recurrence rates, respectively, and still represent a challenge for both techniques. 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/

  3. Superconducting HTS coil made from round cable cooled by liquid nitrogen flow

    Science.gov (United States)

    Šouc, J.; Gömöry, F.; Vojenčiak, M.; Solovyov, M.; Seiler, E.; Kováč, J.; Frolek, L.

    2017-10-01

    The concept of simple cooling arrangement for superconducting coil made from a round cable based on high-temperature superconductor tapes is demonstrated. The cable architecture is similar to the Conductor on Round Core (CORC®) concept: it consists of eight superconducting tapes wound in two layers on a copper tube core in a helical manner. Such a Conductor on Round Tube hand-made cable 4 m long was used to wind the coil with eight turns on 14 cm diameter. Layers of commercial aerogel and polyurethane foam were applied to the coil to provide vacuum-less thermal insulation at its cooling by the flow of liquid nitrogen (LN) in the cable tube. The temperature of superconducting tapes was around 1 K above the coolant temperature in these conditions, causing about 16% reduction of the critical current compared to the LN bath cooling. Electromagnetic performance of the coil was calculated by the model based on the finite element method and the results compared with experimental observations.

  4. CS model coil experimental log book

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  5. Acoustic rainbow trapping by coiling up space

    KAUST Repository

    Ni, Xu

    2014-11-13

    We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

  6. Considerations against a force compensated coil

    International Nuclear Information System (INIS)

    Hassenzahl, W.

    1988-08-01

    The cost of structural components in a large superconducting coil may well exceed the coil and cryostat cost. As a result, the idea of constructing a system composed of two different coil types assembled in such a way that the sources balance and reduce the total structural requirement is oft proposed. A suitable geometry has never been found for the fundamental reason that there can be no force compensated solution. In this paper, the general problem is presented and an analysis of the energy stored and stresses produced in the structure are described in a fundamental way. Finally, the relation between structural mass M and stored energy E, M ≥/rho/E/σ/sub w/, that is valid for all magnetic systems is developed, where /rho/ is the density of the structure and σ/sub w/ is the working stress in the structure. 12 refs., 2 figs

  7. Determination of Coil Inductances Cylindrical Iron Nucleus

    Directory of Open Access Journals (Sweden)

    Azeddine Mazouz

    2014-03-01

    Full Text Available The paper describes the investigation and development of a structure and performance characteristics of a coil iron nucleus cylindrical (C.I.N.C. The coil iron nucleus cylindrical is a nonlinear electro radio in which the moving of the nucleus in a sense or in other causes change in inductance and can reach extreme values at the superposition of nucleus and coil centers. The variation of the inductance and the degree of freedom of movement of the nucleus can lead to a device with electromechanical conversion The aim of this paper is the determination and visualization of self inductance and mutual of the (C.I.N.C based on geometric dimensions and the displacement of the nucleus.  

  8. Internal combustion engine ignition apparatus having a primary winding module

    Energy Technology Data Exchange (ETDEWEB)

    Huntzinger, D.A.; Welsh, T.E. Jr.; Boyer, J.A.

    1990-02-27

    This patent describes a primary winding ignition module that is adapted to be mounted on an internal combustion engine and which is adapted to be magnetically coupled to many separate spark developing units associated with the cylinders of the engine. It comprises: an elongated support, many spaced tubular embers carried by the support, a primary coil winding located in each tubular member having a bore, and conductor means carried by the support connected respectively to opposite ends of a respective primary winding for energizing a respective primary winding. The bores adapted to receive portions of the secondary spark developing units when the module is mounted on an engine.

  9. Technology transfer from laboratory to industry for fabrication of large superconducting coil joints

    International Nuclear Information System (INIS)

    Libeyre, P.; Ciazynski, D.; Decool, P.

    2003-01-01

    The future magnetic thermonuclear fusion reactors will use superconducting magnets. The development during the last decade of the cable-in-conduit conductor (CICC) allows the transport of high current intensities. Nevertheless, the conductor units, which can be produced in industry with such conductors are not long enough to allow constitution of complete winding-pack out of one length. Therefore joints have to be implemented to connect electrically winding units with each other. These joints must fulfil electrical, mechanical, hydraulic and tightness requirements and their design must allow industrial feasibility. The twin-box concept, developed at CEA, was tested with 3 prototype joint samples, and applied to the joints of the ITER Toroidal Field Model Coil, manufactured in the European industry. The tests of this coil in 2001 showed successful operation of these joints, in particular low and reproducible resistances. The concept is now developed with niobium-titanium conductors for the ITER PF Coils and tested this year with a full size joint sample. (author)

  10. Wind power

    International Nuclear Information System (INIS)

    Gipe, P.

    2007-01-01

    This book is a translation of the edition published in the USA under the title of ''wind power: renewable energy for home, farm and business''. In the wake of mass blackouts and energy crises, wind power remains a largely untapped resource of renewable energy. It is a booming worldwide industry whose technology, under the collective wing of aficionados like author Paul Gipe, is coming of age. Wind Power guides us through the emergent, sometimes daunting discourse on wind technology, giving frank explanations of how to use wind technology wisely and sound advice on how to avoid common mistakes. Since the mid-1970's, Paul Gipe has played a part in nearly every aspect of wind energy development from installing small turbines to promoting wind energy worldwide. As an American proponent of renewable energy, Gipe has earned the acclaim and respect of European energy specialists for years, but his arguments have often fallen on deaf ears at home. Today, the topic of wind power is cropping up everywhere from the beaches of Cape Cod to the Oregon-Washington border, and one wind turbine is capable of producing enough electricity per year to run 200 average American households. Now, Paul Gipe is back to shed light on this increasingly important energy source with a revised edition of Wind Power. Over the course of his career, Paul Gipe has been a proponent, participant, observer, and critic of the wind industry. His experience with wind has given rise to two previous books on the subject, Wind Energy Basics and Wind Power for Home and Business, which have sold over 50,000 copies. Wind Power for Home and Business has become a staple for both homeowners and professionals interested in the subject, and now, with energy prices soaring, interest in wind power is hitting an all-time high. With chapters on output and economics, Wind Power discloses how much you can expect from each method of wind technology, both in terms of energy and financial savings. The book updated models

  11. A new type of coil structure called pan-shaped coil of wireless charging system based on magnetic resonance

    Science.gov (United States)

    Yue, Z. K.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Liang, L. H.; Cui, S.

    2017-11-01

    The problem that misalignment between the transmitting coil and the receiving coil significantly impairs the transmission power and efficiency of the system has been attached more and more attention. In order to improve the uniformity of the magnetic field between the two coils to solve this problem, a new type of coil called pan-shaped coil is proposed. Three-dimension simulation models of the planar-core coil and the pan-shaped coil are established using Ansoft Maxwell software. The coupling coefficient between the transmitting coil and the receiving coil is obtained by simulating the magnetic field with the receiving coil misalignment or not. And the maximum percentage difference strength along the radial direction which is defined as the magnetic field uniformity factor is calculated. According to the simulation results of the two kinds of coil structures, it is found that the new type of coil structure can obviously improve the uniformity of the magnetic field, coupling coefficient and power transmission properties between the transmitting coil and the receiving coil.

  12. Multiple coil closure of isolated aortopulmonary collateral

    Directory of Open Access Journals (Sweden)

    Padhi Sumanta

    2010-01-01

    Full Text Available A 7-month-old girl was diagnosed to have large aortopulmonary collateral during evaluation for congestive heart failure. There was no other evidence of cardiopulmonary disease. The collateral was successfully closed with multiple coils delivered sequentially. We describe the issues associated during closure of the aortopulmonary collateral in this case. To the best of our knowledge, this is the first reported case of large aortopulmonary collateral presenting with heart failure in an otherwise structurally normal heart that was closed successfully with multiple coils delivered sequentially.

  13. Self-assembling segmented coiled tubing

    Science.gov (United States)

    Raymond, David W.

    2016-09-27

    Self-assembling segmented coiled tubing is a concept that allows the strength of thick-wall rigid pipe, and the flexibility of thin-wall tubing, to be realized in a single design. The primary use is for a drillstring tubular, but it has potential for other applications requiring transmission of mechanical loads (forces and torques) through an initially coiled tubular. The concept uses a spring-loaded spherical `ball-and-socket` type joint to interconnect two or more short, rigid segments of pipe. Use of an optional snap ring allows the joint to be permanently made, in a `self-assembling` manner.

  14. Fine-tuning of protein domain boundary by minimizing potential coiled coil regions

    International Nuclear Information System (INIS)

    Iwaya, Naoko; Goda, Natsuko; Unzai, Satoru; Fujiwara, Kenichiro; Tanaka, Toshiki; Tomii, Kentaro; Tochio, Hidehito; Shirakawa, Masahiro; Hiroaki, Hidekazu

    2007-01-01

    Structural determination of individual protein domains isolated from multidomain proteins is a common approach in the post-genomic era. Novel and thus uncharacterized domains liberated from intact proteins often self-associate due to incorrectly defined domain boundaries. Self-association results in missing signals, poor signal dispersion and a low signal-to-noise ratio in 1 H- 15 N HSQC spectra. We have found that a putative, non-canonical coiled coil region close to a domain boundary can cause transient hydrophobic self-association and monomer-dimer equilibrium in solution. Here we propose a rational method to predict putative coiled coil regions adjacent to the globular core domain using the program COILS. Except for the amino acid sequence, no preexisting knowledge concerning the domain is required. A small number of mutant proteins with a minimized coiled coil region have been rationally designed and tested. The engineered domains exhibit decreased self-association as assessed by 1 H- 15 N HSQC spectra with improved peak dispersion and sharper cross peaks. Two successful examples of isolating novel N-terminal domains from AAA-ATPases are demonstrated. Our method is useful for the experimental determination of domain boundaries suited for structural genomics studies

  15. Fine-tuning of protein domain boundary by minimizing potential coiled coil regions.

    Science.gov (United States)

    Iwaya, Naoko; Goda, Natsuko; Unzai, Satoru; Fujiwara, Kenichiro; Tanaka, Toshiki; Tomii, Kentaro; Tochio, Hidehito; Shirakawa, Masahiro; Hiroaki, Hidekazu

    2007-01-01

    Structural determination of individual protein domains isolated from multidomain proteins is a common approach in the post-genomic era. Novel and thus uncharacterized domains liberated from intact proteins often self-associate due to incorrectly defined domain boundaries. Self-association results in missing signals, poor signal dispersion and a low signal-to-noise ratio in (1)H-(15)N HSQC spectra. We have found that a putative, non-canonical coiled coil region close to a domain boundary can cause transient hydrophobic self-association and monomer-dimer equilibrium in solution. Here we propose a rational method to predict putative coiled coil regions adjacent to the globular core domain using the program COILS. Except for the amino acid sequence, no preexisting knowledge concerning the domain is required. A small number of mutant proteins with a minimized coiled coil region have been rationally designed and tested. The engineered domains exhibit decreased self-association as assessed by (1)H-(15)N HSQC spectra with improved peak dispersion and sharper cross peaks. Two successful examples of isolating novel N-terminal domains from AAA-ATPases are demonstrated. Our method is useful for the experimental determination of domain boundaries suited for structural genomics studies.

  16. Strand Displacement in Coiled-Coil Structures: Controlled Induction and Reversal of Proximity.

    Science.gov (United States)

    Gröger, Katharina; Gavins, Georgina; Seitz, Oliver

    2017-11-06

    Coiled-coil peptides are frequently used to create new function upon the self-assembly of supramolecular complexes. A multitude of coil peptide sequences provides control over the specificity and stability of coiled-coil complexes. However, comparably little attention has been paid to the development of methods that allow the reversal of complex formation under non-denaturing conditions. Herein, we present a reversible two-state switching system. The process involves two peptide molecules for the formation of a size-mismatched coiled-coil duplex and a third, disruptor peptide that targets an overhanging end. A real-time fluorescence assay revealed that the proximity between two chromophores can be switched on and off, repetitively if desired. Showcasing the advantages provided by non-denaturing conditions, the method permitted control over the bivalent interactions of the tSH2 domain of Syk kinase with a phosphopeptide ligand. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Balloon remodeling may improve angiographic results of stent-assisted coiling of unruptured intracranial aneurysms.

    Science.gov (United States)

    Gentric, Jean-Christophe; Biondi, Alessandra; Piotin, Michel; Mounayer, Charbel; Lobotesis, Kyriakos; Bonafé, Alain; Costalat, Vincent

    2015-04-01

    Endovascular treatment of wide-necked and complex aneurysms may require stent-assisted coiling, either as primary stenting or combined with the balloon remodeling technique (BRT). To compare the angiographic results and clinical outcomes of both strategies in the Safety and Efficacy of Neuroform for Treatment of intracranial Aneurysms (SENAT) registry. SENAT was a prospective, multicenter registry that allowed BRT in conjunction with stenting and coiling with bare platinum coils. Clinical and angiographic outcomes of 97 patients with unruptured aneurysms treated with stenting, 51 after BRT (BRT+) and 46 without balloon assistance (BRT-), were retrieved from the SENAT database. Technical, clinical, and angiographic outcomes were compared between the 2 groups. Periprocedural morbimortality and midterm clinical outcomes were not different between groups. Residual aneurysms were observed in 7.8% of BRT+ and in 21.7% of BRT- (P = .08) at the end of the stenting procedure. Four retreatments were performed during the follow-up period (2 BRT+, 2 BRT-). Twelve- to 18-month anatomic results showed a significant difference between groups, with a residual aneurysm being observed in 6.1% of BRT+ as compared to 22.7% of BRT- patients (P = .03). Primary BRT followed by stent-assisted coiling may be associated with fewer residual aneurysms at 12 to 18 months as compared to stent-assisted coiling alone.

  18. Analysis of short-term total hospital costs and current primary cost drivers of coiling versus clipping for unruptured intracranial aneurysms.

    Science.gov (United States)

    Duan, Yifei; Blackham, Kristine; Nelson, Jeff; Selman, Warren; Bambakidis, Nicholas

    2015-08-01

    No randomized controlled trial has successfully compared outcomes between endovascular coiling and microsurgical clipping for unruptured intracranial aneurysms (UIAs). To perform a cost comparison between index hospitalizations of patients with UIAs treated with coil embolization or surgical clipping to identify the current primary drivers of costs of either management approach. We obtained index hospitalization costs for 125 cases of UIAs treated with coiling or clipping from 2010 to 2012 at our institution. Comparisons were stratified based on patient age, gender, aneurysm size, and aneurysm location. Using linear regressions, we identified clinical parameters that drive total hospital costs. 69 cases were treated with clipping and 56 cases were treated with coiling. Morbidity and length of stay for patients treated with clipping was higher. Total hospital costs and variable direct costs for clipping were significantly lower than for coiling (p=0.003, p<0.001, respectively). Fixed direct costs and fixed indirect costs for clipping were higher than for coiling (p<0.001, p<0.001, respectively). Variable direct costs comprised 50.5% and 68.6% of total hospital costs for clipping and coiling, respectively (p<0.001). Length of stay, aneurysm size, and patient age drove total hospital costs for clipping. Length of stay was a weak driver of total hospital costs for coiling. Total index hospitalization costs for clipping are lower than for coiling. Costs of clipping and coiling are driven by different clinical variables. The cost of coils and devices is the predominant contributor to the higher total costs of coiling. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Treatment of unruptured intracranial aneurysms using internally expanding coils

    Science.gov (United States)

    Suri, M. Fareed K.; Memon, Muhammad Zeeshan; Qureshi, Adnan I.

    2008-01-01

    Background and Purpose The International Subarachnoid Aneurysm Trial (ISAT) showed that patients with intracranial aneurysms treated with coil embolization have better clinical outcomes than those undergoing neurosurgical clipping. However some patients treated endovascularly have recurrence of aneurysms. Low packing density is often cited as a reason for recurrence. Coiling with hydrogel covered coils significantly improves the packing density. We report our initial experience in using a newly introduced design of hydrogel coils. Methods: Three consecutive patients with unruptured aneurysms were treated with hydrogel coated coils. During embolization, a stable framework was first established with bare metal coils, and gel coated coils were used subsequently to increase the packing density. After the procedure, packing density was estimated by calculating the compaction ratio using an online calculator. Results: Successful coil embolization was achieved in all 3 patients. Hydrogel coated coils comprised 11, 63 and 72% of the total coils deployed. One patient had coil herniation that required stent deployment. All patients remained neurologically intact during and after the procedure. Follow-up angiography in 2 patients at 6 months revealed aneurysm stability without any residual neck remnant. Conclusions: The softness of the hydrogel allowed us to deploy coated coils with good packing density. A slight expansion of these coils at the neck can be expected to reduce any neck remnant and potentially inhibit recurrence. PMID:22518218

  20. Computational fluid dynamics of cerebral aneurysm coiling using high-resolution and high-energy synchrotron X-ray microtomography: comparison with the homogeneous porous medium approach.

    Science.gov (United States)

    Levitt, Michael R; Barbour, Michael C; Rolland du Roscoat, Sabine; Geindreau, Christian; Chivukula, Venkat K; McGah, Patrick M; Nerva, John D; Morton, Ryan P; Kim, Louis J; Aliseda, Alberto

    2017-08-01

    Computational modeling of intracranial aneurysms provides insights into the influence of hemodynamics on aneurysm growth, rupture, and treatment outcome. Standard modeling of coiled aneurysms simplifies the complex geometry of the coil mass into a homogeneous porous medium that fills the aneurysmal sac. We compare hemodynamics of coiled aneurysms modeled from high-resolution imaging with those from the same aneurysms modeled following the standard technique, in an effort to characterize sources of error from the simplified model. Physical models of two unruptured aneurysms were created using three-dimensional printing. The models were treated with coil embolization using the same coils as those used in actual patient treatment and then scanned by synchrotron X-ray microtomography to obtain high-resolution imaging of the coil mass. Computational modeling of each aneurysm was performed using patient-specific boundary conditions. The coils were modeled using the simplified porous medium or by incorporating the X-ray imaged coil surface, and the differences in hemodynamic variables were assessed. X-ray microtomographic imaging of coils and incorporation into computational models were successful for both aneurysms. Porous medium calculations of coiled aneurysm hemodynamics overestimated intra-aneurysmal flow, underestimated oscillatory shear index and viscous dissipation, and over- or underpredicted wall shear stress (WSS) and WSS gradient compared with X-ray-based coiled computational fluid dynamics models. Computational modeling of coiled intracranial aneurysms using the porous medium approach may inaccurately estimate key hemodynamic variables compared with models incorporating high-resolution synchrotron X-ray microtomographic imaging of complex aneurysm coil geometry. 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/.

  1. WINDING METHOD SELECTION FOR TECHNICAL IMPLEMENTATION OF FIBER OPTIC COMMUNICATION LINE FOR HIGH-SPEED OBJECT

    Directory of Open Access Journals (Sweden)

    Vyacheslav A. Loparev

    2017-07-01

    Full Text Available The paper deals with fiber-optical cable winding methods for realization of fiber-optic communication line with high-speed object. We consider possible options of coils for optical cable winding providing mobility of one of the cable ends on an object. It is shown that the choice of a winding process is caused by the need of ensuring the minimum deformation of fiber-optical micro cable in case of separation from a winding body. It is revealed that the minimum tension value and its unevenness are observed when reeling from coils with a rocket form. Design ratios for determination of winding parameters are given. It is shown that reduction of tension unevenness reduces the jumps of internal tension and probability of break and emergence of optical signal local attenuation. Decrease in internal stresses occurs due to the absence of overlapping of the coils of the underlying layers with the overlying ones. To confirm the operability and the possibility of constructive implementation of the selected winding scheme, experiments were carried out to perform rocket and other types of winding with the use of a specially designed machine model. It is shown that the application of line rocket winding enables to achieve stability when reeling a cable during the movement and excludes breaks. Attenuation of optical signal decreases due to the increase in the bend minimum radius. This phenomenon is explained by reduction of the internal stresses causing optical signal attenuation in the place of cable separation from the coil.

  2. Automated installations for reeling up of superconducting magnet windings of the accelerating-storage complex

    International Nuclear Information System (INIS)

    Dolzhenkov, V.I.; Elistratov, V.V.; Kuznetsov, Yu.V.; Petrov, V.B.; Popov, V.V.; Savel'ev, A.V.; Sokolov, B.V.; Sytnik, V.V.; Tarakanov, N.M.; Ustinov, E.A.

    1992-01-01

    An automated facility for reeling up the windings of model and full-scale superconducting magnets of the accelerating-storage complex is described. The control system monitors superconducting cable tension, transport carriage linear velocity and some other parameters. Maximum length of the winded coils is 6 m. Cable tension stability - 5%

  3. Design study of coated conductor direct drive wind turbine generator for small scale demonstration

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Jensen, Bogi Bech

    2012-01-01

    We have investigated the properties of a superconducting direct drive generator suitable for demonstration in a small scale 11 kW wind turbine. The engineering current density of the superconducting field windings is based on properties of coated conductors wound into coils holding of the order 6...

  4. Processing and transport properties of high Jc silver clad Bi-2223 tapes and coils

    International Nuclear Information System (INIS)

    Haldar, P.; Hoehn, J.G. Jr.; Balachandran, U.

    1993-02-01

    The powder-in-tube process has been used to fabricate long lengths of flexible, high J c , silver clad Bi-2223 HTS conductors. By improving thermo-mechanical processing and precursor powder preparationwe have succeeded in achieving J c 's exceeding 4 x 10 4 A/cm 2 at liquid nitrogen (77K) and > 10 5 A/cm 2 at liquid helium (4.2K) and liquid neon (27K) temperatures for short tapesamples. Detailed measurements with high applied magnetic fields are reported. Several long tapes up to 10 meters in length have also been fabricated and co-wound into small superconducting pancake coils using the ''wind-and-react'' approach. Transport measurements at 77K and 4.2K for these coils are also reported

  5. Wind energy systems information user study

    Energy Technology Data Exchange (ETDEWEB)

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-01-01

    This report describes the results of a series of telephone interviews with potential users of information on wind energy conversion. These interviews, part of a larger study covering nine different solar technologies, attempted to identify: the type of information each distinctive group of information users needed, and the best way of getting information to that group. Groups studied include: wind energy conversion system researchers; wind energy conversion system manufacturer representatives; wind energy conversion system distributors; wind turbine engineers; utility representatives; educators; county agents and extension service agents; and wind turbine owners.

  6. Rogowski coils for studies of detonator initiation

    Science.gov (United States)

    Tasker, Douglas

    2017-06-01

    The Rogowski coil dates back to 1887 and it has commonly been employed to measure rapid changes of electrical currents without direct contact with the circuits, especially in high energy density applications. Recently, it has been used to measure currents in relatively low energy devices such as semiconductor circuits; here we report its utility in the analysis of detonator initiation. From an electrical perspective, the coil is essentially an air-cored transformer and measures the temporal rate of change of current dI/dt. Following a careful characterization of the circuit, an accurate measurement of this derivative is shown to provide a complete solution of the detonator circuit, including current, voltage, power and energy delivered to the detonator. The dependence of the electrical sensitivity, accuracy and bandwidth on coil design will be discussed and a new printed circuit design will be presented. Interesting features in the initiation of exploding bridgewire detonators have been observed with this coil and the results of various experiments will be discussed.

  7. Large coil test facility instrumentation system design

    International Nuclear Information System (INIS)

    Walstrom, P.L.; Fletcher, W.M.; Goddard, J.S.; Murphy, J.L.

    1979-01-01

    The design of the instrumentation system for the Large Coil Test Facility (LCTF) is described. Sensors are divided into two categories: coil diagnostic sensors, installed in the test coils; and facility sensors, installed in the various systems of the test facility in order to monitor their performance. After signal conditioning, data from the ''fast'' channels are multiplexed, digitized, and stored in four microcomputer systems programmed to be used in a ring buffer mode to record data before and after receipt of a random trigger from the normal zone detection circuitry. ''Slow'' channels are digitized by a scanner and buffered by a microcomputer. Selected data channels are continuously displayed on digital or recorded on strip chart recorders. The microcomputer systems are interfaced to a central minicomputer system for display and archival storage. Facility variables are digitized by a separate scanner system. Certain critical fault variables are compared with set point values, and if they are out of range, cause a programmable logic controller to initiate an emergency coil energy dump. 2 refs

  8. Coiling of ruptured pericallosal artery aneurysms.

    NARCIS (Netherlands)

    Menovsky, T.; Rooij, W.J.J. van; Sluzewski, M.; Wijnalda, D.

    2002-01-01

    OBJECTIVE: To assess the technical feasibility of treating ruptured pericallosal artery aneurysms with detachable coils and to evaluate the anatomic and clinical results. METHODS: Over a period of 27 months, 12 patients with a ruptured pericallosal artery aneurysm were treated with detachable

  9. Voltage distribution within superconducting coils during quench

    International Nuclear Information System (INIS)

    Tominaka, T.; Hara, N.; Kuroda, K.

    1988-01-01

    A computer program which can be applied to the calculation of voltage distribution within superconducting coils during quench has been developed. The calculation is compared with an experiment for a small superconducting solenoid, and the propriety of the calculation is discussed

  10. Ureteral stents: coil strength and durometer.

    Science.gov (United States)

    Hendlin, Kari; Dockendorf, Kelly; Horn, Christina; Pshon, Nicole; Lund, Brynn; Monga, Manoj

    2006-07-01

    To evaluate the coil strength before and after urine exposure and the stiffness of commercially available double-J ureteral stents because both properties may affect stent performance and patient comfort. Twelve commercially available 6F ureteral stents were tested for coil strength before and after 30 days of urine exposure. The proximal end of each stent was inserted through a 2-mm hole in bologna, allowed to recoil, and then pulled using a handheld force gauge. Ten different commercially available ureteral stent models were tested for tensile strength using an MTS MicroBionix Testing System and Testworks II software and a 5 N load cell. The Cook Black Silicone and Cook C-Flex stents had the strongest coil strengths before urine exposure at 0.480 +/- 0.0 lb (P Circon Double J stent and Bard InLay. Ureteral stents can be differentiated according to their coil strength and stiffness. The impact of these properties on stent performance and patient comfort deserve additional evaluation. The significant variability found in stent stiffness among stents from different lot numbers suggests poor quality assurance in biomaterials or stent processing and increases the complexity of cross-stent comparisons.

  11. Moving coil linear variable differential transformer.

    Science.gov (United States)

    Ellis, J F; Walstrom, P L

    1978-03-01

    A moving-coil linear variable differential transformer with no ferromagnetic components is described. The device is essentially interchangeable with a conventional moving-core linear variable differential transformer, but is virtually unaffected by ambient magnetic fields up to 8 T. The transducer is connected to a standard commercially available carrier amplifier for signal conditioning.

  12. Testing electrical insulation of LCT coils and instrumentation

    International Nuclear Information System (INIS)

    Luton, J.N.; Ulbricht, A.R.; Ellis, J.F.; Shen, S.S.; Wilson, C.T.; Okuno, K.; Siewerdt, L.O.; Zahn, G.R.; Zichy, J.A.

    1986-09-01

    Three of the superconducting test coils in the Large Coil Task (LCT) use conductors cooled internally by forced flow of helium. In the other three coils, the conductors are cooled externally by a bath of helium. The coils and facility are designed for rapid discharges (dumps) at voltages up to 2.5 kV, depending on coil design. Many coil sensors are connected electrically to the conductors. These sensor leads and signal conditioning equipment also experience high voltage. High-potential tests of ground insulation were performed on all components of the International Fusion Superconducting Magnet Test Facility (IFSMTF). Coil insulation was also tested by ring-down tests that produced voltage distributions within the coils like those occurring during rapid discharge. Methods were developed to localize problem areas and to eliminate them. The effect on breakdown voltage near the Paschen minimum of magnetic fields up to 2 T was investigated

  13. Superconducting coil design for a tokamak experimental power reactor

    International Nuclear Information System (INIS)

    Turner, L.R.; Wang, S.T.; Smelser, P.

    1977-01-01

    Superconducting toroidal field (TF) and polodial-field (PF) coils have been designed for the proposed Argonne National Laboratory experimental power reactor (EPR). Features of the design include: (1) Peak field of 8 T at 4.2 K or 10 T at 3.0 K. (2) Constant-tension shape for the TF coils, corrected for the finite number (16) of coils. (3) Analysis of errors in coil alignment. (4) Comparison of safety aspects of series-connected and parallel-connected coils. (5) A 60 kA sheet conductor of NbTi with copper stabilizer and stainless steel for support. (6) Superconducting PF coils outside the TF coils. (7) The TF coils shielded from pulsed fields by high-purity aluminum

  14. Structural design of the superconducting toroidal field coils for ITER

    International Nuclear Information System (INIS)

    Wong, F.M.G.; Sborchia, C.; Thome, R.J.; Malkov, A.; Titus, P.H.

    1995-01-01

    Structural design issues and features of the superconducting toroidal field (TF) coils for the International Thermonuclear Experimental Reactor (ITER) will be discussed. Selected analyses of the structural and mechanical behavior of the ITER TF coils will also be presented. (orig.)

  15. GBNV encoded movement protein (NSm) remodels ER network via C-terminal coiled coil domain

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pratibha; Savithri, H.S., E-mail: bchss@biochem.iisc.ernet.in

    2015-08-15

    Plant viruses exploit the host machinery for targeting the viral genome–movement protein complex to plasmodesmata (PD). The mechanism by which the non-structural protein m (NSm) of Groundnut bud necrosis virus (GBNV) is targeted to PD was investigated using Agrobacterium mediated transient expression of NSm and its fusion proteins in Nicotiana benthamiana. GFP:NSm formed punctuate structures that colocalized with mCherry:plasmodesmata localized protein 1a (PDLP 1a) confirming that GBNV NSm localizes to PD. Unlike in other movement proteins, the C-terminal coiled coil domain of GBNV NSm was shown to be involved in the localization of NSm to PD, as deletion of this domain resulted in the cytoplasmic localization of NSm. Treatment with Brefeldin A demonstrated the role of ER in targeting GFP NSm to PD. Furthermore, mCherry:NSm co-localized with ER–GFP (endoplasmic reticulum targeting peptide (HDEL peptide fused with GFP). Co-expression of NSm with ER–GFP showed that the ER-network was transformed into vesicles indicating that NSm interacts with ER and remodels it. Mutations in the conserved hydrophobic region of NSm (residues 130–138) did not abolish the formation of vesicles. Additionally, the conserved prolines at positions 140 and 142 were found to be essential for targeting the vesicles to the cell membrane. Further, systematic deletion of amino acid residues from N- and C-terminus demonstrated that N-terminal 203 amino acids are dispensable for the vesicle formation. On the other hand, the C-terminal coiled coil domain when expressed alone could also form vesicles. These results suggest that GBNV NSm remodels the ER network by forming vesicles via its interaction through the C-terminal coiled coil domain. Interestingly, NSm interacts with NP in vitro and coexpression of these two proteins in planta resulted in the relocalization of NP to PD and this relocalization was abolished when the N-terminal unfolded region of NSm was deleted. Thus, the NSm

  16. Compressing DNA sequence databases with coil

    Directory of Open Access Journals (Sweden)

    Hendy Michael D

    2008-05-01

    Full Text Available Abstract Background Publicly available DNA sequence databases such as GenBank are large, and are growing at an exponential rate. The sheer volume of data being dealt with presents serious storage and data communications problems. Currently, sequence data is usually kept in large "flat files," which are then compressed using standard Lempel-Ziv (gzip compression – an approach which rarely achieves good compression ratios. While much research has been done on compressing individual DNA sequences, surprisingly little has focused on the compression of entire databases of such sequences. In this study we introduce the sequence database compression software coil. Results We have designed and implemented a portable software package, coil, for compressing and decompressing DNA sequence databases based on the idea of edit-tree coding. coil is geared towards achieving high compression ratios at the expense of execution time and memory usage during compression – the compression time represents a "one-off investment" whose cost is quickly amortised if the resulting compressed file is transmitted many times. Decompression requires little memory and is extremely fast. We demonstrate a 5% improvement in compression ratio over state-of-the-art general-purpose compression tools for a large GenBank database file containing Expressed Sequence Tag (EST data. Finally, coil can efficiently encode incremental additions to a sequence database. Conclusion coil presents a compelling alternative to conventional compression of flat files for the storage and distribution of DNA sequence databases having a narrow distribution of sequence lengths, such as EST data. Increasing compression levels for databases having a wide distribution of sequence lengths is a direction for future work.

  17. Reduction of Thermal Loss in HTS Windings by Using Magnetic Flux Deflection

    Science.gov (United States)

    Tsuzuki, K.; Miki, M.; Felder, B.; Koshiba, Y.; Izumi, M.; Umemoto, K.; Aizawa, K.; Yanamoto, T.

    Efforts on the generation of intensified magnetic flux have been made for the optimized shape of HTS winding applications. This contributes to the high efficiency of the rotating machines using HTS windings. Heat generation from the HTS windings requires to be suppressed as much as possible, when those coils are under operation with either direct or alternative currents. Presently, the reduction of such thermal loss generated by the applied currents on the HTS coils is reported with a magnetic flux deflection system. The HTS coils are fixed together with flattened magnetic materials to realize a kind of redirection of the flux pathway. Eventually, the magnetic flux density perpendicular to the tape surface (equivalent to the a-b plane) of the HTS tape materials is reduced to the proximity of the HTS coil. To verify the new geometry of the surroundings of the HTS coils with magnetic materials, a comparative study of the DC coil voltage was done for different applied currents in prototype field-pole coils of a ship propulsion motor.

  18. Coiled-coil forming peptides for the induction of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Božič Abram, Sabina [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Graduate School of Biomedicine, University of Ljubljana, Ljubljana 1000 (Slovenia); Aupič, Jana [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Doctoral Programme in Chemical Sciences, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000 (Slovenia); Dražić, Goran [Laboratory for Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Gradišar, Helena [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia); Jerala, Roman, E-mail: roman.jerala@ki.si [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia)

    2016-04-08

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  19. CCBuilder 2.0: Powerful and accessible coiled-coil modeling.

    Science.gov (United States)

    Wood, Christopher W; Woolfson, Derek N

    2018-01-01

    The increased availability of user-friendly and accessible computational tools for biomolecular modeling would expand the reach and application of biomolecular engineering and design. For protein modeling, one key challenge is to reduce the complexities of 3D protein folds to sets of parametric equations that nonetheless capture the salient features of these structures accurately. At present, this is possible for a subset of proteins, namely, repeat proteins. The α-helical coiled coil provides one such example, which represents ≈ 3-5% of all known protein-encoding regions of DNA. Coiled coils are bundles of α helices that can be described by a small set of structural parameters. Here we describe how this parametric description can be implemented in an easy-to-use web application, called CCBuilder 2.0, for modeling and optimizing both α-helical coiled coils and polyproline-based collagen triple helices. This has many applications from providing models to aid molecular replacement for X-ray crystallography, in silico model building and engineering of natural and designed protein assemblies, and through to the creation of completely de novo "dark matter" protein structures. CCBuilder 2.0 is available as a web-based application, the code for which is open-source and can be downloaded freely. http://coiledcoils.chm.bris.ac.uk/ccbuilder2. We have created CCBuilder 2.0, an easy to use web-based application that can model structures for a whole class of proteins, the α-helical coiled coil, which is estimated to account for 3-5% of all proteins in nature. CCBuilder 2.0 will be of use to a large number of protein scientists engaged in fundamental studies, such as protein structure determination, through to more-applied research including designing and engineering novel proteins that have potential applications in biotechnology. © 2017 The Authors Protein Science published by Wiley Periodicals, Inc. on behalf of The Protein Society.

  20. Coiled coil peptides as universal linkers for the attachment of recombinant proteins to polymer therapeutics

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Pola, Robert; Laga, Richard; Ulbrich, Karel; Bednárová, Lucie; Maloň, Petr; Sieglová, Irena; Král, Vlastimil; Fábry, Milan; Vaněk, O.

    2011-01-01

    Roč. 12, č. 10 (2011), s. 3645-3655 ISSN 1525-7797 R&D Projects: GA ČR GA203/08/0543; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : coiled coil * polymer therapeutics * drug targeting Subject RIV: CC - Organic Chemistry Impact factor: 5.479, year: 2011

  1. Plasmodium vivax antigen discovery based on alpha-helical coiled coil protein motif.

    Directory of Open Access Journals (Sweden)

    Nora Céspedes

    Full Text Available Protein α-helical coiled coil structures that elicit antibody responses, which block critical functions of medically important microorganisms, represent a means for vaccine development. By using bioinformatics algorithms, a total of 50 antigens with α-helical coiled coil motifs orthologous to Plasmodium falciparum were identified in the P. vivax genome. The peptides identified in silico were chemically synthesized; circular dichroism studies indicated partial or high α-helical content. Antigenicity was evaluated using human sera samples from malaria-endemic areas of Colombia and Papua New Guinea. Eight of these fragments were selected and used to assess immunogenicity in BALB/c mice. ELISA assays indicated strong reactivity of serum samples from individuals residing in malaria-endemic regions and sera of immunized mice, with the α-helical coiled coil structures. In addition, ex vivo production of IFN-γ by murine mononuclear cells confirmed the immunogenicity of these structures and the presence of T-cell epitopes in the peptide sequences. Moreover, sera of mice immunized with four of the eight antigens recognized native proteins on blood-stage P. vivax parasites, and antigenic cross-reactivity with three of the peptides was observed when reacted with both the P. falciparum orthologous fragments and whole parasites. Results here point to the α-helical coiled coil peptides as possible P. vivax malaria vaccine candidates as were observed for P. falciparum. Fragments selected here warrant further study in humans and non-human primate models to assess their protective efficacy as single components or assembled as hybrid linear epitopes.

  2. Data-Driven Prediction and Design of bZIP Coiled-Coil Interactions

    Science.gov (United States)

    Potapov, Vladimir; Kaplan, Jenifer B.; Keating, Amy E.

    2015-01-01

    Selective dimerization of the basic-region leucine-zipper (bZIP) transcription factors presents a vivid example of how a high degree of interaction specificity can be achieved within a family of structurally similar proteins. The coiled-coil motif that mediates homo- or hetero-dimerization of the bZIP proteins has been intensively studied, and a variety of methods have been proposed to predict these interactions from sequence data. In this work, we used a large quantitative set of 4,549 bZIP coiled-coil interactions to develop a predictive model that exploits knowledge of structurally conserved residue-residue interactions in the coiled-coil motif. Our model, which expresses interaction energies as a sum of interpretable residue-pair and triplet terms, achieves a correlation with experimental binding free energies of R = 0.68 and significantly out-performs other scoring functions. To use our model in protein design applications, we devised a strategy in which synthetic peptides are built by assembling 7-residue native-protein heptad modules into new combinations. An integer linear program was used to find the optimal combination of heptads to bind selectively to a target human bZIP coiled coil, but not to target paralogs. Using this approach, we designed peptides to interact with the bZIP domains from human JUN, XBP1, ATF4 and ATF5. Testing more than 132 candidate protein complexes using a fluorescence resonance energy transfer assay confirmed the formation of tight and selective heterodimers between the designed peptides and their targets. This approach can be used to make inhibitors of native proteins, or to develop novel peptides for applications in synthetic biology or nanotechnology. PMID:25695764

  3. Application of Coiled Coil Peptides in Liposomal Anticancer Drug Delivery Using a Zebrafish Xenograft Model.

    Science.gov (United States)

    Yang, Jian; Shimada, Yasuhito; Olsthoorn, René C L; Snaar-Jagalska, B Ewa; Spaink, Herman P; Kros, Alexander

    2016-08-23

    The complementary coiled coil forming peptides E4 [(EIAALEK)4] and K4 [(KIAALKE)4] are known to trigger liposomal membrane fusion when tethered to lipid vesicles in the form of lipopeptides. In this study, we examined whether these coiled coil forming peptides can be used for drug delivery applications. First, we prepared E4 peptide modified liposomes containing the far-red fluorescent dye TO-PRO-3 iodide (E4-Lipo-TP3) and confirmed that E4-liposomes could deliver TP3 into HeLa cells expressing K4 peptide on the membrane (HeLa-K) under cell culture conditions in a selective manner. Next, we prepared doxorubicin-containing E4-liposomes (E4-Lipo-DOX) and confirmed that E4-liposomes could also deliver DOX into HeLa-K cells. Moreover, E4-Lipo-DOX showed enhanced cytotoxicity toward HeLa-K cells compared to free doxorubicin. To prove the suitability of E4/K4 coiled coil formation for in vivo drug delivery, we injected E4-Lipo-TP3 or E4-Lipo-DOX into zebrafish xenografts of HeLa-K. As a result, E4-liposomes delivered TP3 to the implanted HeLa-K cells, and E4-Lipo-DOX could suppress cancer proliferation in the xenograft when compared to nontargeted conditions (i.e., zebrafish xenograft with free DOX injection). These data demonstrate that coiled coil formation enables drug selectivity and efficacy in vivo. It is envisaged that these findings are a step forward toward biorthogonal targeting systems as a tool for clinical drug delivery.

  4. Splenic Artery Embolization in Blunt Trauma: A Single-Center Retrospective Comparison of the Use of Gelatin Sponge Versus Coils.

    Science.gov (United States)

    Rasuli, Pasteur; Moosavi, Bardia; French, Gordon J; Petrcich, William; Hammond, Ian

    2017-12-01

    The purpose of this study was to compare the efficacy of gelatin sponge with that of coils for splenic artery embolization in the treatment of blunt splenic injury. A single-center retrospective review was performed with the records of 63 patients (45 men, 18 women; mean age, 45.5 years; range, 16-84 years) with blunt splenic injury treated at a tertiary care trauma center by splenic artery embolization with gelatin sponge (n = 30 patients) or metallic coils (n = 33 patients) between 2005 and 2014. The two groups had comparable median American Association for the Surgery of Trauma grades of IV and comparable angiographic appearances regarding active extravasation and pseudoaneurysm formation at preembolization splenic arteriography (p = 0.32). Clinical outcomes and procedure-related outcomes were evaluated. The success rates were similar in the two groups: splenic artery embolization failed in 6.6% (2/30) of patients in the gelatin sponge group and 12.1% (4/33) in the coil embolization group (p = 0.45; 95% CI, -30.1% to 19.2%). Major complications occurred in six patients (20.0%) in the gelatin sponge group and in six patients (18.1%) in the coil group (p = 0.85; 95% CI, -23.0% to 26.6%). Minor complications occurred in three patients (10.0%) in the gelatin sponge group and seven patients (21.2%) in the coil group (p = 0.21; 95% CI, -35.4% to 14.0%). Procedure time was significantly shorter in the gelatin sponge group (median, 32 minutes; interquartile range, 18-48 minutes) than in the coil group (median, 53 minutes; interquartile range, 30-76 minutes) (p = 0.01). Splenic artery embolization with gelatin sponge appears to be as effective and as safe as coil embolization and can be completed in a shorter time.

  5. Transport of one SC coil through the village of Meyrin

    CERN Multimedia

    1956-01-01

    The energizing coils of the Synchro-cyclotron magnet were manufactured in Belgium before travelling to Basel in Switzerland by boat and continuing by road to Geneva. The first coil reached Geneva in December 1955, with the second following in early 1956. The coils were stored in a hangar at the Geneva airport before they were brought to CERN in May 1956.

  6. The umbilical coiling index, a review of the literature

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Franx, Arie; van Alderen, Elise D.; Nikkels, Peter G. J.; Visser, Gerard H. A.

    2005-01-01

    Our aim was to review the literature on umbilical cord coiling. Relevant articles in English published between 1966 and 2003 were retrieved by a Medline search and cross-referencing. The normal umbilical cord coiling index (UCI) is 0.17 (+/- 0.009) spirals completed per cm. Abnormal cord coiling,

  7. The Roach muscle bundle and umbilical cord coiling

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Nikkels, Peter G. J.; Franx, Arie; Visser, Gerard H. A.

    2007-01-01

    To determine if presence of the Roach muscle, a small muscle bundle lying just beside the umbilical artery, contributes to umbilical cord coiling. 251 umbilical cords were examined. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length in cm. Cords were

  8. The coil array method for creating a dynamic imaging volume.

    Science.gov (United States)

    Smith, Elliot; Freschi, Fabio; Repetto, Maurizio; Crozier, Stuart

    2017-08-01

    Gradient strength and speed are limited by peripheral nerve stimulation (PNS) thresholds. The coil array method allows the gradient field to be moved across the imaging area. This can help reduce PNS and provide faster imaging for image-guided therapy systems such as the magnetic resonance imaging-guided linear accelerator (MRI-linac). The coil array is designed such that many coils produce magnetic fields, which combine to give the desired gradient profile. The design of the coil array uses two methods: either the singular value decomposition (SVD) of a set of field profiles or the electromagnetic modes of the coil surface. Two whole-body coils and one experimental coil were designed to investigate the method. The field produced by the experimental coil was compared to simulated results. The experimental coil region of uniformity (ROU) was moved along the z axis as shown in simulation. The highest observed field deviation was 16.9% at the edge of the ROU with a shift of 35 mm. The whole-body coils showed a median field deviation across all offsets below 5% with an eight-coil basis when using the SVD design method. Experimental results show the feasibility of a moving imaging region within an MRI with a low number of coils in the array. Magn Reson Med 78:784-793, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  9. Strain and stress of the ASDEX multipole magnetic coils

    International Nuclear Information System (INIS)

    Jandl, O.; Pillsticker, M.

    1978-01-01

    A brief description of the technical concept of the multipole magnetic field coils for the ASDEX tokamak is given. The various loads of the coils are explained in quality. To compute displacement and stress of the coils FEM computer programs are used. The computing models applied to this problem are founded and the results and the conclusions are reported. (orig.) [de

  10. Optimum Combination of Pickup Coil Type and Magnetically Shielded Room for Maximum SNR to Measure Biomagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K. K.; Lee, Y. H.; Kang, C. S.; Kim, J. M.; Park, Y. K. [Biosignal Research Center, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2007-10-15

    We have investigated the optimum combination of the environmental noise condition and type of SQUID pickup coil in order to obtain maximum signal-to-noise ratio (SNR). The measurement probe consists of 1st order gradiometer with pickup coils of 100 mm, 70 mm, and 50 mm baseline length, a 2nd order gradiometer with 50 mm baseline, and a magnetometer. The pickup coils are fabricated by winding Nb wire on a bobbin with 200 mm diameter. Noise and heart signal of a healthy male were measured by various SQUID sensors with different types of pickup coils in various magnetically shielded rooms (MSR), and compared to each other. The shielding factors were found to be 43 dB, 35 dB and 25 dB at 0.1 Hz for MSR-AS, MSR-BS, MSR-CS, respectively. White noises were 3.5 fT/Hz{sup 1/2}, 4.5 fT/Hz {sup 1/2} and 3 fT/Hz{sup 1/2} for the 1st order gradiometers, the 2nd order gradiometers, and magnetometer for all MSRs. SNR of the magnetometer was up to 56 dB in MSR-AS, while the 1st order axial gradiometer with 70 mm baseline length was up to 54 dB in MSR-BS. The 2nd order axial gradiometer with 50 mm baseline length of pickup coil was found to be up to 40 dB in MSR-CS.

  11. Armature reaction effects on HTS field winding in HTS machine

    DEFF Research Database (Denmark)

    Mijatovic, Nenad; Jensen, Bogi Bech

    2013-01-01

    sensitivity to both armature reaction intensity and angular position with respect to the HTS coils. Furthermore, the characterization of the HTS feld winding has been correlated to the electromagnetic torque of the machine where the maximal Ic reduction of 21% has been observed for the maximum torque....

  12. Winding workshop for the ISR low beta Superconducting Quadrupole Prototype

    CERN Multimedia

    1975-01-01

    From right to left one sees the wire spool with its electro-magnetic brake to ensure a constant tension of the superconducting wire, a pulley with a wire length recording and the winding machine. In front on the table a finished coil. In the back the heavy clamping tool. See also 7510213X, 7510213X.

  13. Preferred side-chain constellations at antiparallel coiled-coil interfaces.

    Science.gov (United States)

    Hadley, Erik B; Testa, Oliver D; Woolfson, Derek N; Gellman, Samuel H

    2008-01-15

    Reliable predictive rules that relate protein sequence to structure would facilitate postgenome predictive biology and the engineering and de novo design of peptides and proteins. Through a combination of experiment and analysis of the protein data bank (PDB), we have deciphered and rationalized new rules for helix-helix interfaces of a common protein-folding and association motif, the antiparallel dimeric coiled coil. These interfaces are defined by a specific pattern of interactions among largely hydrophobic side chains often referred to as knobs-into-holes (KIH) packing: a knob from one helix inserts into a hole formed by four residues on the partner. Previous work has focused on lateral interactions within the KIH motif, for example, between an a position on one helix and a d' position on the other in an antiparallel coiled coil. We show that vertical interactions within the KIH motif, such as a'-a-a', are energetically important as well. The experimental and database analyses concur regarding preferred vertical combinations, which can be rationalized as leading to favorable side-chain interactions that we call constellations. The findings presented here highlight an unanticipated level of complexity in coiled-coil interactions, and our analysis of a few specific constellations illustrates a general, multipronged approach to addressing this complexity.

  14. Historical review: another 50th anniversary--new periodicities in coiled coils.

    Science.gov (United States)

    Gruber, Markus; Lupas, Andrei N

    2003-12-01

    In 1953, Francis Crick and Linus Pauling both proposed models of supercoiled alpha helices ('coiled coils') for the structure of keratin. These were the first attempts at modelling the tertiary structure of a protein. Crick emphasized the packing mode of the side-chains ('knobs-into-holes'), which required a periodicity of seven residues over two helical turns (7/2) and a supercoil in the opposite sense of the constituent helices. By contrast, Pauling envisaged a broader set of periodicities (4/1, 7/2, 18/5, 15/4, 11/3) and supercoils of both senses. Crick's model became canonical and the 'heptad repeat' essentially synonymous with coiled coils, but 50 years later new crystal structures and protein sequences show that the less common periodicities envisaged by Pauling also occur in coiled coils, adding a variant packing mode ('knobs-to-knobs') to the standard model. Pauling's laboratory notebooks suggest that he searched unsuccessfully for this packing mode in 1953.

  15. Coiled-Coil Proteins Facilitated the Functional Expansion of the Centrosome

    Science.gov (United States)

    Kuhn, Michael; Hyman, Anthony A.; Beyer, Andreas

    2014-01-01

    Repurposing existing proteins for new cellular functions is recognized as a main mechanism of evolutionary innovation, but its role in organelle evolution is unclear. Here, we explore the mechanisms that led to the evolution of the centrosome, an ancestral eukaryotic organelle that expanded its functional repertoire through the course of evolution. We developed a refined sequence alignment technique that is more sensitive to coiled coil proteins, which are abundant in the centrosome. For proteins with high coiled-coil content, our algorithm identified 17% more reciprocal best hits than BLAST. Analyzing 108 eukaryotic genomes, we traced the evolutionary history of centrosome proteins. In order to assess how these proteins formed the centrosome and adopted new functions, we computationally emulated evolution by iteratively removing the most recently evolved proteins from the centrosomal protein interaction network. Coiled-coil proteins that first appeared in the animal–fungi ancestor act as scaffolds and recruit ancestral eukaryotic proteins such as kinases and phosphatases to the centrosome. This process created a signaling hub that is crucial for multicellular development. Our results demonstrate how ancient proteins can be co-opted to different cellular localizations, thereby becoming involved in novel functions. PMID:24901223

  16. Wind Energy Resource Atlas of Oaxaca

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.; Heimiller, D.; George, R.

    2003-08-01

    The Oaxaca Wind Resource Atlas, produced by the National Renewable Energy Laboratory's (NREL's) wind resource group, is the result of an extensive mapping study for the Mexican State of Oaxaca. This atlas identifies the wind characteristics and distribution of the wind resource in Oaxaca. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications.

  17. Wind Energy Resource Atlas of Sri Lanka and the Maldives

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.; Heimiller, D.; George, R.

    2003-08-01

    The Wind Energy Resource Atlas of Sri Lanka and the Maldives, produced by the National Renewable Energy Laboratory's (NREL's) wind resource group identifies the wind characteristics and distribution of the wind resource in Sri Lanka and the Maldives. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications.

  18. Coil embolization of the splenic artery: impact on splenic volume.

    Science.gov (United States)

    Preece, Stephen R; Schriber, Stacey M; Choudhury, Kingshuk R; Suhocki, Paul V; Smith, Tony P; Kim, Charles Y

    2014-06-01

    To determine the impact of coil embolization of the splenic artery on splenic volume based on computed tomography (CT) imaging. Splenic artery embolization (SAE) was performed in 148 consecutive patients over an 8-year period in an institutional review board-approved retrospective study. Of these, 60 patients (36 men; mean age, 49 y) had undergone contrast-enhanced CT before and after SAE with a mean time interval of 355 days. Pre- and postembolization splenic volumes were calculated with volume-rendering software. Presence of Howell-Jolly bodies was ascertained on laboratory tests. A trauma control group consisted of 39 patients with splenic laceration and follow-up CT but no splenic intervention. SAE in trauma patients resulted in an insignificant decrease in mean spleen size from 224 cm(3) to 190 cm(3) (P = .222). However, postembolization splenic volume was significantly smaller than follow-up volume in the trauma control group (353 cm(3); P Howell-Jolly bodies after SAE. No patients required repeat embolization or splenectomy. Coil embolization of the splenic artery resulted in a modest but significant decrease in splenic volume when performed distally; proximal embolization resulted in an insignificant volume change. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  19. Modeling the shape of a noncircular toroidal field coil

    International Nuclear Information System (INIS)

    Shah, V.N.; Marshall, N.H.

    1983-01-01

    Operating and transient forces acting on toroidal field coils may cause conductors and insulation to slide or break and may lead to quenching of the coil. Therefore, it is essential that each individual turn of the coil be modeled for detailed analysis of the coil structure. For this, a special purpose computer program is needed. As a first step in developing such a computer program, the authors present a finite element analysis of a turn of noncircular coil subjected to electromagnetic loading. A turn of superconducting coil is represented by a thin ring modeled by curved finite elements. Of the several curved beam elements reported in the literature, the strain element with two nodes, six degrees-of-freedom, and constant radius of curvature converges fastest for thin-deep arches whose geometrical characteristics are similar to those of a turn of toroidal field coil. They present an algorithm to model a noncircular ring using the number of strain elements satisfying the continuity of slopes at their nodes. This paper verifies the finite element model of a coil shape subjected to a toroidal magnetic field by solving three problems: circular and elliptic coils with the same inner and outer radii, a D-shaped coil, and a compound coil consisting of C- and D-shaped segments. The first problem shows that the resultant vertical force in the upper half of the coil is independent of coil shape. The remaining two problems calculate stresses that represent the constant tension in the D-shaped coil and in each segment of the compound coil. The results of the three problems compare well with the analytical results

  20. Computational study for the effects of coil configuration on blood flow characteristics in coil-embolized cerebral aneurysm.

    Science.gov (United States)

    Otani, Tomohiro; Ii, Satoshi; Shigematsu, Tomoyoshi; Fujinaka, Toshiyuki; Hirata, Masayuki; Ozaki, Tomohiko; Wada, Shigeo

    2017-05-01

    Coil embolization of cerebral aneurysms with inhomogeneous coil distribution leads to an incomplete occlusion of the aneurysm. However, the effects of this factor on the blood flow characteristics are still not fully understood. This study investigates the effects of coil configuration on the blood flow characteristics in a coil-embolized aneurysm using computational fluid dynamics (CFD) simulation. The blood flow analysis in the aneurysm with coil embolization was performed using a coil deployment (CD) model, in which the coil configuration was constructed using a physics-based simulation of the CD. In the CFD results, total flow momentum and kinetic energy in the aneurysm gradually decayed with increasing coil packing density (PD), regardless of the coil configuration attributed to deployment conditions. However, the total shear rate in the aneurysm was relatively high and the strength of the local shear flow varied based on the differences in coil configuration, even at adequate PDs used in clinical practice (20-25 %). Because the sufficient shear rate reduction is a well-known factor in the blood clot formation occluding the aneurysm inside, the present study gives useful insight into the effects of coil configuration on the treatment efficiency of coil embolization.

  1. Subunit b-Dimer of the Escherichia coli ATP Synthase Can Form Left-Handed Coiled-Coils

    Science.gov (United States)

    Wise, John G.; Vogel, Pia D.

    2008-01-01

    One remaining challenge to our understanding of the ATP synthase concerns the dimeric coiled-coil stator subunit b of bacterial synthases. The subunit b-dimer has been implicated in important protein interactions that appear necessary for energy conservation and that may be instrumental in energy conservation during rotary catalysis by the synthase. Understanding the stator structure and its interactions with the rest of the enzyme is crucial to the understanding of the overall catalytic mechanism. Controversy exists on whether subunit b adopts a classic left-handed or a presumed right-handed dimeric coiled-coil and whether or not staggered pairing between nonhomologous residues in the homodimer is required for intersubunit packing. In this study we generated molecular models of the Escherichia coli subunit b-dimer that were based on the well-established heptad-repeat packing exhibited by left-handed, dimeric coiled-coils by employing simulated annealing protocols with structural restraints collected from known structures. In addition, we attempted to create hypothetical right-handed coiled-coil models and left- and right-handed models with staggered packing in the coiled-coil domains. Our analyses suggest that the available structural and biochemical evidence for subunit b can be accommodated by classic left-handed, dimeric coiled-coil quaternary structures. PMID:18326648

  2. Structural attributes for the recognition of weak and anomalous regions in coiled-coils of myosins and other motor proteins

    Science.gov (United States)

    2012-01-01

    Background Coiled-coils are found in different proteins like transcription factors, myosin tail domain, tropomyosin, leucine zippers and kinesins. Analysis of various structures containing coiled-coils has revealed the importance of electrostatic and hydrophobic interactions. In such domains, regions of different strength of interactions need to be identified since they could be biologically relevant. Findings We have updated our coiled-coil validation webserver, now called COILCHECK+, where new features were added to efficiently identify the strength of interaction at the interface region and measure the density of charged residues and hydrophobic residues. We have examined charged residues and hydrophobic ladders, using a new algorithm called CHAHO, which is incorporated within COILCHECK + server. CHAHO permits the identification of spatial charged residue patches and the continuity of hydrophobic ladder which stabilizes and destabilizes the coiled-coil structure. Conclusions The availability of such computational tools should be useful to understand the importance of spatial clustering of charged residues and the continuity of hydrophobic residues at the interface region of coiled-coil dimers. COILCHECK + is a structure based tool to validate coiled-coil stability; it can be accessed at http://caps.ncbs.res.in/coilcheckplus. PMID:23009691

  3. CCBuilder: an interactive web-based tool for building, designing and assessing coiled-coil protein assemblies.

    Science.gov (United States)

    Wood, Christopher W; Bruning, Marc; Ibarra, Amaurys Á; Bartlett, Gail J; Thomson, Andrew R; Sessions, Richard B; Brady, R Leo; Woolfson, Derek N

    2014-11-01

    The ability to accurately model protein structures at the atomistic level underpins efforts to understand protein folding, to engineer natural proteins predictably and to design proteins de novo. Homology-based methods are well established and produce impressive results. However, these are limited to structures presented by and resolved for natural proteins. Addressing this problem more widely and deriving truly ab initio models requires mathematical descriptions for protein folds; the means to decorate these with natural, engineered or de novo sequences; and methods to score the resulting models. We present CCBuilder, a web-based application that tackles the problem for a defined but large class of protein structure, the α-helical coiled coils. CCBuilder generates coiled-coil backbones, builds side chains onto these frameworks and provides a range of metrics to measure the quality of the models. Its straightforward graphical user interface provides broad functionality that allows users to build and assess models, in which helix geometry, coiled-coil architecture and topology and protein sequence can be varied rapidly. We demonstrate the utility of CCBuilder by assembling models for 653 coiled-coil structures from the PDB, which cover >96% of the known coiled-coil types, and by generating models for rarer and de novo coiled-coil structures. CCBuilder is freely available, without registration, at http://coiledcoils.chm.bris.ac.uk/app/cc_builder/. © The Author 2014. Published by Oxford University Press.

  4. Comparison of individual canine retraction using HYCON device and nickel titanium closed coil spring: In vivo study

    OpenAIRE

    Ruby Mathew; Swati Saraswata Acharya; Ramachandra Prabhakar; M K Karthikeyan; R Saravanan; N Rajvikram

    2015-01-01

    Objective: To compare the individual canine retraction using HYCON device and Nickel Titanium closed coil springs. Materials and Methods: The sample consists of 20 patients, 10 males and 10 females. Class1 bimaxillary protrusion cases were selected for the study with age group ranging from 14 to 23 years. HYCON device was placed on the right side of the maxillary arch and Nickel Titanium closed coil spring were placed on left side of the maxillary arch. Lateral cephalograms, OPG and study mod...

  5. Umbilical Cord Coiling and Zygosity: Is there a Link?

    Science.gov (United States)

    Coetzee, André Joannou; Castro, Eumenia; Peres, Luiz Cesar

    2015-01-01

    The aim of this study was to analyze abnormalities of umbilical coiling index (UCI) in twin gestation to test whether the coiling is genetically influenced by zygosity. Data retrieved comprised gestational age (GA), chorionicity, fetal gender, and UCI. The mean UCI of hypercoiled cords in monochorionic placentas was 0.55 coils/cm and 0.49 coils/cm in dichorionic placentas with discordant fetal gender (P = 0.2629). In conclusion, no significant statistical difference between UCI in monochorionic and dichorionic twin placentas with discordant fetal gender was identified, suggesting that zygosity does not play a role in umbilical coiling induction.

  6. SSC [Superconducting Super Collider] dipole coil production tooling

    International Nuclear Information System (INIS)

    Carson, J.A.; Barczak, E.J.; Bossert, R.C.; Brandt, J.S.; Smith, G.A.

    1989-03-01

    Superconducting Super Collider dipole coils must be produced to high precision to ensure uniform prestress and even conductor distribution within the collared coil assembly. Tooling is being prepared at Fermilab for the production of high precision 1M and 16.6M SSC dipole coils suitable for mass production. The design and construction methods builds on the Tevatron tooling and production experience. Details of the design and construction methods and measured coil uniformity of 1M coils will be presented. 4 refs., 10 figs

  7. SSC (Superconducting Super Collider) dipole coil production tooling

    Energy Technology Data Exchange (ETDEWEB)

    Carson, J.A.; Barczak, E.J.; Bossert, R.C.; Brandt, J.S.; Smith, G.A.

    1989-03-01

    Superconducting Super Collider dipole coils must be produced to high precision to ensure uniform prestress and even conductor distribution within the collared coil assembly. Tooling is being prepared at Fermilab for the production of high precision 1M and 16.6M SSC dipole coils suitable for mass production. The design and construction methods builds on the Tevatron tooling and production experience. Details of the design and construction methods and measured coil uniformity of 1M coils will be presented. 4 refs., 10 figs.

  8. The IEA large coil task test results in IFSMTF

    International Nuclear Information System (INIS)

    Lubell, M.S.; Clinard, J.A.; Dresner, L.

    1987-01-01

    The Large Coil Task (LCT) is an international collaboration of the United States, EURATOM, Japan, and Switzerland to develop large superconducting magnets for fusion reactors. The testing phase of LCT was completed on September 3, 1987. All six coils exceeded the design goals, both as single coils and in six-coil toroidal tests. In addition, a symmetric torus test was performed in which a maximum field of 9 T was reached in all coils simultaneously. These are by far the largest magnets (either in size, weight, or stored energy) ever to achieve such a field. 6 refs., 6 figs., 3 tabs

  9. Coil compaction after embolization of the superior mesenteric artery pseudoaneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Hama, Yukihiro; Iwasaki, Yoshie; Kaji, Tatsumi; Kusano, Shoichi [Department of Radiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, 3590042 Saitama (Japan); Hatsuse, Kazuo [Department of Surgery I, National Defense Medical College, 3-2 Namiki, Tokorozawa, 3590042 Saitama (Japan)

    2002-07-01

    A 58-year-old man with an abscess of the psoas muscle was returned to our hospital with hematemesis. Two years earlier, he had undergone coil embolization for a superior mesenteric artery (SMA) pseudoaneurysm secondary to pancreatitis. Based on the physical examination, serum amylase level, and abdominal radiographs, a diagnosis of acute exacerbation of pancreatitis and coil compaction of the SMA pseudoaneurysm was made. The patient underwent re-embolization for the coil compaction using interlocking detachable coils. His condition improved gradually, and he was discharged 3 weeks later. To our knowledge, this is the first report of coil compaction of SMA pseudoaneurysm. (orig.)

  10. Random coil chemical shift for intrinsically disordered proteins

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Brander, Søren; Poulsen, Flemming Martin

    2011-01-01

    Secondary chemical shift analysis is the main NMR method for detection of transiently formed secondary structure in intrinsically disordered proteins. The quality of the secondary chemical shifts is dependent on an appropriate choice of random coil chemical shifts. We report random coil chemical....... Temperature has a non-negligible effect on the (13)C random coil chemical shifts, so temperature coefficients are reported for the random coil chemical shifts to allow extrapolation to other temperatures. The pH dependence of the histidine random coil chemical shifts is investigated in a titration series...

  11. Planar quadrature coil design using shielded-loop resonators

    DEFF Research Database (Denmark)

    Stensgaard, A

    1997-01-01

    The shielded-loop resonator is known to have a low capacitive sample loss due to a perfect balancing. In this paper, it is demonstrated that shielded-loop technology also can be used to improve design of planar quadrature coils. Both a dual-loop circuit and especially a dual-mode circuit may...... benefit from use of shielded-loop resonators. Observations in measurements agree with theory for both a dual-loop coil and a dual-mode coil. The coils were designed for use as transmit/receive coil for 1H imaging and spectroscopy at 4.7 T in rat brain....

  12. Baculovirus FP25K Localization: Role of the Coiled-Coil Domain.

    Science.gov (United States)

    Garretson, Tyler A; McCoy, Jason C; Cheng, Xiao-Wen

    2016-11-01

    Two types of viruses are produced during the baculovirus life cycle: budded virus (BV) and occlusion-derived virus (ODV). A particular baculovirus protein, FP25K, is involved in the switch from BV to ODV production. Previously, FP25K from the model alphabaculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) was shown to traffic ODV envelope proteins. However, FP25K localization and the domains involved are inconclusive. Here we used a quantitative approach to study FP25K subcellular localization during infection using an AcMNPV bacmid virus that produces a functional AcMNPV FP25K-green fluorescent protein (GFP) fusion protein. During cell infection, FP25K-GFP localized primarily to the cytoplasm, particularly amorphous structures, with a small fraction being localized in the nucleus. To investigate the sequences involved in FP25K localization, an alignment of baculovirus FP25K sequences revealed that the N-terminal putative coiled-coil domain is present in all alphabaculoviruses but absent in betabaculoviruses. Structural prediction indicated a strong relatedness of AcMNPV FP25K to long interspersed element 1 (LINE-1) open reading frame 1 protein (ORF1p), which contains an N-terminal coiled-coil domain responsible for cytoplasmic retention. Point mutations and deletions of this domain lead to a change in AcMNPV FP25K localization from cytoplasmic to nuclear. The coiled-coil and C-terminal deletion viruses increased BV production. Furthermore, a betabaculovirus FP25K protein lacking this N-terminal coiled-coil domain localized predominantly to the nucleus and exhibited increased BV production. These data suggest that the acquisition of this N-terminal coiled-coil domain in FP25K is important for the evolution of alphabaculoviruses. Moreover, with the divergence of preocclusion nuclear membrane breakdown in betabaculoviruses and membrane integrity in alphabaculoviruses, this domain represents an alphabaculovirus adaptation for nuclear trafficking

  13. Modelling of coil-loaded wire antenna using composite multiple domain basis functions

    CSIR Research Space (South Africa)

    Lysko, AA

    2010-03-01

    Full Text Available –ciency in modeling of the above-mentioned types of geometrical structures with a traditional method of moments (MoM). The reduction in the number of variables is accomplished by a logical aggregation/grouping of the individual straight wire segments... of the antenna is shown in Figure 1. The drawing shows the two straight wire segments joined by a helical coil. Both straight segments as well as the coil are modeled by straight thin wire sub-segments. The monopole is fed with a 1-Volt delta gap generator...

  14. Coil supporting device for a nuclear fusion device

    International Nuclear Information System (INIS)

    Kuno, Kazuo.

    1976-01-01

    Object: To reduce a thermal stress of a coil such as a magnetic limiter to minimize stress acting on a protective tube of the coil. Structure: A coil within a protective tube has its outer periphery surrounded and supported by a heat-resisting material such as ceramic at more than two positions suitably spaced lengthwise of a coil conductor, and heat insulating members are interposed between both sides of the coil and the protective tube so that it may be retained with respect to the width of the coil. Further, a heat-resisting resilient member is inserted in a clearance between an outer circumference and an inner circumference of the coil to allow a radial displacement of the coil. As a result, elongation of the coil due to thermal expansion may be escaped at the aforesaid two supports to reduce thermal stress of the coil and protective tube to support the coil within the protective tube in positively heat-resisting and insulating manner. (Kamimura, M.)

  15. Deep brain transcranial magnetic stimulation using variable "Halo coil" system

    Science.gov (United States)

    Meng, Y.; Hadimani, R. L.; Crowther, L. J.; Xu, Z.; Qu, J.; Jiles, D. C.

    2015-05-01

    Transcranial Magnetic Stimulation has the potential to treat various neurological disorders non-invasively and safely. The "Halo coil" configuration can stimulate deeper regions of the brain with lower surface to deep-brain field ratio compared to other coil configurations. The existing "Halo coil" configuration is fixed and is limited in varying the site of stimulation in the brain. We have developed a new system based on the current "Halo coil" design along with a graphical user interface system that enables the larger coil to rotate along the transverse plane. The new system can also enable vertical movement of larger coil. Thus, this adjustable "Halo coil" configuration can stimulate different regions of the brain by adjusting the position and orientation of the larger coil on the head. We have calculated magnetic and electric fields inside a MRI-derived heterogeneous head model for various positions and orientations of the coil. We have also investigated the mechanical and thermal stability of the adjustable "Halo coil" configuration for various positions and orientations of the coil to ensure safe operation of the system.

  16. Magnetic field from arbitrarily shaped flat coils with filamentary, ribbon, and rectangular cross sections

    International Nuclear Information System (INIS)

    Weissenburger, D.W.; Christensen, U.R.

    1975-01-01

    This report describes the derivation of three groups of equations: (1) Field components from an arbitrarily shaped filament lying in a plane. (2) Field components from an arbitrarily shaped ribbon of infinitesimal thickness with center line lying in a plane. (3) Field components from an arbitrarily shaped bar of rectangular cross section with its center line lying in a plane. In all three cases analytical expressions for the field components were found for an infinitesimal element of the cross section. These expressions are then integrated numerically along the arbitrarily shaped center line of the coil to obtain the three field components. As a check for accuracy the calculated field values of an elliptically shaped coil were compared to an existing analytic expression for a filamentary elliptical coil

  17. Spontaneous quenches of a high temperature superconducting pancake coil

    Energy Technology Data Exchange (ETDEWEB)

    Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States); Aized, D.; Campbell, J.M.; Schwall, R.E. [American Superconductor Corp., Westborough, MA (United States)

    1995-09-01

    A double-pancake coil made of Bi-2223/Ag high temperature superconducting (HTS) tape was constructed with an embedded heater and graded conductors to study the stability and quench propagation in HTS coils. The experiments were performed with liquid nitrogen and gaseous helium cooling in temperatures ranging from 5 to 77 K. The coil was very stable, and no ``normal`` zone was sustained or propagated with local pulsed heating. However, spontaneous quenches of the cod were experienced. This was found to be the result of having the coil current higher than that of the lower I{sub c} sections of the coil for a long time. This quench process took minutes to develop--much longer than would be expected in a low temperature superconducting coil. The quench behaved more like a spreading and continuous heating of an increasingly larger partially resistive section of the coil than like a sequential ``normal`` front propagation.

  18. Design of a dynamic transcranial magnetic stimulation coil system.

    Science.gov (United States)

    Ge, Sheng; Jiang, Ruoli; Wang, Ruimin; Chen, Ji

    2014-08-01

    To study the brain activity at the whole-head range, transcranial magnetic stimulation (TMS) researchers need to investigate brain activity over the whole head at multiple locations. In the past, this has been accomplished with multiple single TMS coils that achieve quasi whole-head array stimulation. However, these designs have low resolution and are difficult to position and control over the skull. In this study, we propose a new dynamic whole-head TMS mesh coil system. This system was constructed using several sagittal and coronal directional wires. Using both simulation and real experimental data, we show that by varying the current direction and strength of each wire, this new coil system can form both circular coils or figure-eight coils that have the same features as traditional TMS coils. Further, our new system is superior to current coil systems because stimulation parameters such as size, type, location, and timing of stimulation can be dynamically controlled within a single experiment.

  19. Endovascular treatment of intracranial aneurysms with matrix coils: immediate posttreatment results, clinical outcome and follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Kimchi, T.J.; Spears, J.; Lee, S.K.; Ter Brugge, K. [University Health Network, University of Toronto, Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, Toronto, ON (Canada); Willinsky, R.A. [University Health Network, University of Toronto, Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, Toronto, ON (Canada); Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, ON (Canada)

    2007-03-15

    Endovascular aneurysm repair with coils has become a safe and effective alternative to surgical clipping. Efforts have been made to create coils that will facilitate aneurysm healing and reduce recurrence. The purpose of this study was to review the safety and durability of our aneurysm treatment using Matrix coils. A total of 39 aneurysms in 38 patients, aged 30 to 77 years, were treated using Matrix coils in 42 procedures. Two procedures were unsuccessful, and 12 were done using only Matrix coils. Aneurysm volume, packing density and percentage length of Matrix coils were calculated. The treatment results, procedural complication rate and clinical outcome were analyzed. Follow-up examinations were available for 34 procedures with a mean follow-up of 4.9 months (maximum 13.5 months). Angiographic results were similar to those following the use of platinum coils, with complete occlusion or a residual neck in 82.5% of procedures. Six procedures (14%) were complicated with platelet aggregation. Recanalization occurred in 32% of the patients. Nine patients (26%) had major recanalization and were retreated. One patient had a re-bleed 5 months after the treatment resulting in severe disability. The mean packing density of 39.2% in the recanalized aneurysms was similar to that in the nonrecanalized group. In our series, treatment with Matrix coils had a complication rate similar to that reported with platinum coils. However, we had a higher percentage of major recanalizations requiring retreatment. We believe that the absorption of the polymer contributes to the failure of formation of a stable scar within the aneurysm. (orig.)

  20. Coil irrigation in sugar cane (Saccharum officinarum

    Directory of Open Access Journals (Sweden)

    Jesús Sánchez Gutiérrez

    2016-01-01

    Full Text Available This study was made at the Basic Seed Bank of the Local Sugar Cane Research Station for the Mideastern Cuba, based in Camaguey, on brown carbonate soil, between 2013 and 12014. Coil irrigation was applied to meet the water requirements for the crop, according to the edafoclimatic conditions and the different phenological phases it has. The Savo method was used to determine useful rain water. Adjustment and complementation of the irrigation program was based on indicators that characterize the exploitation scheme. The machine´s working parameters were determined to meet the water needs, and increase crop´s overall yields. The evaluations and results achieved have contributed to new proposals for management and operation of coil irrigation, and they are important to increase its efficiency.

  1. Voice coil based scanning probe microscopy

    Czech Academy of Sciences Publication Activity Database

    Klapetek, P.; Valtr, M.; Duchoň, V.; Sobota, Jaroslav

    2012-01-01

    Roč. 7, č. 6 (2012), 332:1-7 ISSN 1931-7573 R&D Projects: GA MPO FR-TI1/241; GA AV ČR KAN311610701; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : SPM * Voice coil * Interferometry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.524, year: 2012

  2. Coil irrigation in sugar cane (Saccharum officinarum)

    OpenAIRE

    Jesús Sánchez Gutiérrez; Yoslén Fernández Gálvez; Mayra Martínez Pírez; Camilo Bonet Pérez; Manuel A Hernández Victoria; Arlandy Noy Perera

    2016-01-01

    This study was made at the Basic Seed Bank of the Local Sugar Cane Research Station for the Mideastern Cuba, based in Camaguey, on brown carbonate soil, between 2013 and 12014. Coil irrigation was applied to meet the water requirements for the crop, according to the edafoclimatic conditions and the different phenological phases it has. The Savo method was used to determine useful rain water. Adjustment and complementation of the irrigation program was based on indicators that characterize the...

  3. Acute lung injury following refrigeration coil deicing.

    Science.gov (United States)

    McKeown, Nathanael J; Burton, Brent T

    2012-03-01

    We report a case of a worker who developed ALI requiring mechanical ventilatory support after attempting to melt ice condensate by applying the flame of an oxy-acetylene torch to refrigeration coils charged with a halocarbon refrigerant in a closed environment. A discussion of possible etiologies are discussed, including phosgene, carbonyl fluoride, and nitrogen oxides. Primary prevention with adequate respiratory protection is recommended whenever deicing is performed in a closed space environment.

  4. A new moving-coil microelectrode puller.

    Science.gov (United States)

    Ensor, D R

    1979-03-01

    This paper describes an improved electrode puller for the manufacture of glass microelectrodes or micropipettes. The instrument resembles a conventional horizontal two-stage, solenoid-powered electrode puller but the pull is now developed by a light moving-coil and a fixed permanent magnet, using the principle of the moving-coil loudspeaker. In a conventional puller the force is generated by a solenoid with a massive moving-iron core. In this new puller the moving-coil solenoid responds much more rapidly to changing currents because of its greatly reduced inductance, and a substantial reduction in mass to 25 g, gives more acceleration from a comparable force. The sudden discharge of a capacitor bank through the coil accelerates the glass quickly during the last stage of the pull. This rapid acceleration is of importance in the formation of good electrodes with fine tips. For the prototype, an electronic control unit was constructed which allows the parameters necessary for the manufacture of electrodes to be set and regulated accurately and repeatedly, so that series of electrodes of constant shapes can be made. The length of the electrode shank may be predetermined over a wide range and tip diameters down to 0.08 micron have already been measured. The angle of the taper that supports the tip may be varied from less than 1 to over 6 degrees. The mechanical design of the instrument is comparatively simple, as it has only one moving part, while the relative complexity of the electronic control section should not present any manufacturing difficulties. Although this puller has been used mainly to make single-barrel fine electrodes from borosilicate glass, it is adaptable for other purposes. The extent of the control over the shape of the shank of the electrode renders it particularly suitable for the manufacture of composite, ion-sensitive electrodes.

  5. Wind Energy Education and Outreach Project

    Energy Technology Data Exchange (ETDEWEB)

    Loomis, David G. [Illinois State Univ., Normal, IL (United States)

    2013-01-09

    The purpose of Illinois State University's wind project was to further the education and outreach of the university concerning wind energy. This project had three major components: to initiate and coordinate a Wind Working Group for the State of Illinois, to launch a Renewable Energy undergraduate program, and to develop the Center for Renewable Energy that will sustain the Illinois Wind Working Group and the undergraduate program.

  6. A study on nuclear heat load tolerable for NET/TF coils cooled by internal flow of helium II

    International Nuclear Information System (INIS)

    Hofmann, A.

    1988-02-01

    NbTi cables cooled by internal flow of superfluid helium are considered an option for the design of NET/TF coils with about 11 T peak fields. Starting from an available winding cross section of 0.61x0.61 m 2 for a 8 MA turns coil made of a 16 kA conductor it is shown that sufficient hydraulic cross section can be provided within such cables to remove the expected thermal load resulting from nuclear heating with exponential decay from inboard to outboard side of the winding. The concept is a pancake type coil with 1.8 K helium fed-in the high field region of each pancake. The temperature distribution within such coils is calculated, and the local safety margin is determined from temperature and field. The calculation takes account of nuclear and a.c. heating, and of thermal conductance between the individual layers and the coil casing. It is shown that operation with 1.8 K inlet and about 3 K outlet temperature is possible. The electrical insulation with about 0.5 mm thickness proves to provide sufficient thermal insulation. No additional thermal shield is required between the coil casing and the winding package. Two different types of conductors are being considered: a) POLO type cable with quadratic cross section and a central circular coolant duct, and b) an LCT type cable with two conductors wound in hand. Both concepts with about 500 m length of the cooland channels are shown to meet the requirements resulting from a peak nuclear heat load of 0.3 mW/cm 3 in the inboard turns. The hydraulic diameters are sufficient to operate each coils with self-sustained fountain effect pumps. Even appreciably higher heat loads with up to 3 mW/cm 3 of nuclear heating can be tolerated for the POLO type cable when the hydraulic diameter is enlarged to its maximum of 17 mm. (orig.) [de

  7. Permanent magnet motor drives with switched stator windings

    Energy Technology Data Exchange (ETDEWEB)

    Nipp, E.

    1999-06-01

    Permanent magnet (PM) motors are today regarded as an interesting solution for a wide range of inverter-fed variable-speed drives. The generally increased interest in these motors has led to many investigations on their feasibility for vehicle propulsion. Consequently, they are also of interest for traction applications which led to the research project that is presented in this thesis. The most important advantages that are expected in comparison to the state of the art asynchronous motors are lower losses and a higher torque density. Often the field weakening speed range is important, but difficult to obtain with PM machines because the inductance in the direction of the magnetization tends to be low. An alternative can be to switch different coils groups of the stator winding into different configurations. This is the central topic of this thesis. Various aspects of the design of PM motor drives are considered with special attention to the requirements for the application of the switched winding concept. The studies were thereby limited to the inner rotor, radial flux topology. It was found that two winding parts per phase, implying four different winding connections, is the only interesting solution. An advantage of switched windings is that the internal voltage of the machine will never exceed the maximum inverter output, which increases the operation safety. Furthermore the machine design can uncompromisingly be optimized for operation below base speed, which means low inductances implying a large air gap length and thick magnets. A problem with switched windings is that circulating currents can occur. To diminish them, a 2/3 magnet covering of the pole surface must be chosen in combination with a non-salient rotor. Moreover it was found that the eddy current losses in the magnets can reach non-negligible levels and must be considered when designing a drive system. The major drawback of switched stator windings is probably the occurrence of torque

  8. Single coil bistable, bidirectional micromechanical actuator

    Science.gov (United States)

    Tabat, Ned; Guckel, Henry

    1998-09-15

    Micromechanical actuators capable of bidirectional and bistable operation can be formed on substrates using lithographic processing techniques. Bistable operation of the microactuator is obtained using a single coil and a magnetic core with a gap. A plunger having two magnetic heads is supported for back and forth linear movement with respect to the gap in the magnetic core, and is spring biased to a neutral position in which the two heads are on each side of the gap in the core. The single electrical coil is coupled to the core and is provided with electrical current to attract one of the heads toward the core by reluctance action to drive the plunger to a limit of travel in one direction. The current is then cut off and the plunger returns by spring action toward the gap, whereafter the current is reapplied to the coil to attract the other head of the plunger by reluctance action to drive the plunger to its other limit of travel. This process can be repeated at a time when switching of the actuator is required.

  9. Transcatheter coil embolisation of pulmonary arteriovenous malformations

    International Nuclear Information System (INIS)

    Wingen, M.; Guenther, R.W.

    2001-01-01

    Evaluation of technical success, complications and long-term results of transcatheter coil embolisation in pulmonary arteriovenous malformations (pAVMs). Material and Methods: Transcatheter embolisations of 46 pAVMs in 14 patients were analysed retrospectively, and, 5 years after treatment, the patients were interviewed by telefone concerning persistent symptoms and complications. Main symptoms before embolisation were dyspnoe (86%), hypoxaemia (100%), cerebral ischemia (21%), and hemoptysis (14%); 11 patients (79%) suffered from hereditary hemorrhagic telangiectasia. Results: Embolisation with an average of 3,9 coils (min. 1, max. 19 coils) per pAVM yielded technical success in all cases. Only two minor complications, transitory pleuritis and a small lung infarction were observed. On follow up examination after 5 years either no residual complaints or substantial improvement of dyspnoe were reported; no patient suffered from neurologic or hemorrhagic complications after the embolisation. Conclusion: Transcatheter embolisation is a safe and minimally invasive therapy for pAVMs and has rightfully replaced surgical resection as the therapy of choice. (orig.) [de

  10. Carbon footprint of automotive ignition coil

    Science.gov (United States)

    Chang, Huey-Ling; Chen, Chih-Ming; Sun, Chin-Huang; Lin, Hung-Di

    2015-07-01

    In recent years, environmental issues, such as climate change and global warming due to the excessive development of industry, have attracted increasing attention of citizens worldwide. It is known that CO2 accounts for the largest proportion of greenhouse gases. Therefore, how to reduce CO2 emissions during the life cycle of a product to lessen its impact on environment is an important topic in the industrial society. Furthermore, it is also of great significance to cut down the required energy so as to lower its production costs during the manufacturing process nowadays. This study presents the carbon footprint of an automotive ignition coil and its partial materials are defined to explore their carbon emissions and environmental impact. The model IPCC GWP100a calculates potential global greenhouse effect by converting them into CO2 equivalents. In this way, the overall carbon footprint of an ignition coil can be explored. By using IPCC GWP100a, the results display that the shell has the most carbon emissions. The results can help the industry reduce the carbon emissions of an ignition coil product.

  11. Aneurysmal subarachnoid hemorrhage: outcome of aneurysm clipping versus coiling in anterior circulation aneurysm

    International Nuclear Information System (INIS)

    Wadd, I.H.; Haroon, A.; Ansari, S.

    2015-01-01

    To compare the neurological outcome of microsurgical clipping versus coiling in patients with anterior circulation aneurysm. Study Design: Comparative study. Place and Duration of Study: Department of Neurosurgery, Lahore General Hospital, Lahore, from January 2010 to December 2013. Methodology: Patients aged 14 - 60 years, with ruptured cerebral aneurysm of anterior circulation and World Federation of Neurosurgical Society (WFNS) grades 1, 2 and 3 were included. Patients more than 60 years, medically unfit patient and posterior circulation aneurysms and WFNS grades 4 and 5 were excluded. Aneurysm sac obliteration was done in randomized manner with microsurgical clipping or coiling. Postoperatively, the patients were assessed and followed-up upto one year for outcome parameters on the bases of WFNS grade and Modified Ranking Scale (mRS) as favourable (mRS =2 ) and unfavourable (mRS > 2). Results: Among 140 subjects selected for study, 70 were included in group A, i.e. coiling and other 70 were in group B, i.e. clipping. The median age of patients in group A was 52.5 ± 10 years and in group B was 51.00 ± years. Overall, 56 (40%) males, 28 (60%) males in each group; and 84 (60%) females, 42 (60%) in each group were included. The male to female ratio in this study was 1:1.5. In group A, i.e. coiling, 27 (38.6%) patients had no disability (grades 1 and 2), 25 (35.7%) were slightly disabled (grade 3) and 18 (25.7%) had moderate disability (grade 4); whereas in group B, i.e. clipping group 23 (32.9%) patients had no disability (grades 1 and 2), 23 (32.9%) were slightly disabled (grade 3) and 24 (34.3%) had moderate disability (grade 4). At one year follow-up, in group A, favourable outcome was achieved in 56 (80%) of patients compared to 48 (68.6%) in group B; whilst, 14 (20%) patients in group A and 22 (33.1%) in group B showed unfavourable outcome. Although mortality rate was higher in clipping (n=3, 4.3%) as compared to coiling (n=1, 1.4%), but was not statistically

  12. Wind energy

    CERN Document Server

    Woll, Kris

    2016-01-01

    Across the country, huge open spaces are covered in gently turning wind turbines. In Wind Energy, explore how these machines generate electricity, learn about the history of wind power, and discover the latest advances in the field. Easy-to-read text, vivid images, and helpful back matter give readers a clear look at this subject. Features include a table of contents, infographics, a glossary, additional resources, and an index. Aligned to Common Core Standards and correlated to state standards. Core Library is an imprint of Abdo Publishing, a division of ABDO.

  13. Design and testing of a coil-unit barrel for helical coil electromagnetic launcher

    Science.gov (United States)

    Yang, Dong; Liu, Zhenxiang; Shu, Ting; Yang, Lijia; Ouyang, Jianming

    2018-01-01

    A coil-unit barrel for a helical coil electromagnetic launcher is described. It provides better features of high structural strength and flexible adjustability. It is convenient to replace the damaged coil units and easy to adjust the number of turns in the stator coils due to the modular design. In our experiments, the highest velocity measured for a 4.5-kg projectile is 47.3 m/s and the mechanical reinforcement of the launcher could bear 35 kA peak current. The relationship between the energy conversion efficiency and the inductance gradient of the launcher is also studied. In the region of low inductance gradient, the efficiency is positively correlated with the inductance gradient. However, in the region of high inductance gradient, the inter-turn arc erosion becomes a major problem of limiting the efficiency and velocity of the launcher. This modular barrel allows further studies in the inter-turn arc and the variable inductance gradient helical coil launcher.

  14. A Novel DC-Coil-Free Hybrid-Excited Machine with Consequent-Pole PM Rotor

    Directory of Open Access Journals (Sweden)

    Qingsong Wang

    2018-03-01

    Full Text Available This paper proposes a new DC coil free hybrid excited machine concept, which has no external field windings. The technical novelty is the integration of field windings and armature windings. DC bias current is injected into the excitation and the field windings in the traditional hybrid excited machine are eliminated. Compared with traditional hybrid-excited machines with additional field windings, the proposed machine can realize a higher slot utilization ratio, hence achieve a higher torque density and a wider flux adjusting range. Another advantage of the proposed machine is that the voltage drop associated with flux regulation is small due to the small DC resistance, and the torque generating capability at the flux regulating region can be improved accordingly. The rotor is specifically designed with magnet-iron sequences and a consequent-pole, in which the permanent magnet and iron pole are alternatively employed. A bi-directional flux modulating effect can be achieved, which can contribute to the magnetic coupling in the air-gap. Analytical derivation is used to describe the operating principle, and the proposed machine was optimally designed using the Tabu search algorithm. A prototype was made, and its performances investigated through experimental tests.

  15. Moving-table MR angiography of the peripheral runoff vessels: comparison of body coil and dedicated phased array coil systems.

    Science.gov (United States)

    Huber, A; Scheidler, J; Wintersperger, B; Baur, A; Schmidt, M; Requardt, M; Holzknecht, N; Helmberger, T; Billing, A; Reiser, M

    2003-05-01

    The aim of our study was to compare the signal-to-noise ratio and the diagnostic accuracy of moving-table MR angiography of the peripheral arteries with body coil and dedicated phased array coil systems. Forty patients were examined with digital subtraction angiography and moving-table MR angiography with a 1.5-T MR imaging system either with a body coil (n = 20) or with a dedicated phased array coil (n = 20). The timing of contrast material was performed with real-time MR fluoroscopy. For the iliac artery, upper leg, and lower leg, the mean values for signal-to-noise ratios were 56, 51, and 17, respectively, for the body coil, and 54, 74, and 64, respectively, for the dedicated phased array coil. For the body coil, sensitivity and specificity in identifying stenosis greater than 50% and occlusions were 100% and 96%, respectively, for the iliac arteries, and 100% and 96%, respectively, for the upper leg. For the dedicated phased array coil, sensitivity and specificity for stenosis greater than 50% and occlusions were 100% and 96%, respectively, for the iliac arteries, and 100% and 98%, respectively, for the upper leg. Sensitivity and specificity were inferior for the body coil (88% and 85%) compared with the dedicated phased array coil (100% and 96%) in the lower leg. A significant difference of the mean values of contrast-to-noise ratio was found before and after subtraction for the dedicated phased array coil and body-coil techniques (Student's t test, p coil, the dedicated peripheral phased array surface coil system improves signal-to-noise ratio for the upper and lower leg and diagnostic accuracy in the lower leg.

  16. World Wind

    Data.gov (United States)

    National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...

  17. Synthesis and functionalization of coiled carbon filaments

    Science.gov (United States)

    Hikita, Muneaki

    Coiled carbon filaments have one of the most attractive three-dimensional forms in carbon materials due to their helical morphologies. Because of their shape and carbon structure, they exhibit excellent mechanical and electrical properties such as superelasticity, low Young's modulus, relatively high electrical conductivity, and good electromagnetic (EM) wave absorption. Therefore, they are good candidates as fillers in composite materials for tactile sensor and electromagnetic interference shielding. In medical areas of interests, coiled carbon filaments can be used as micro and nano heaters or trigger for thermotherapy and biosensors using EM wave exposure because absorbed EM waves by coiled carbon filaments are converted into heat. Although various shapes of coiled carbon filaments have been discovered, optimum synthesis conditions and growth mechanisms of coiled carbon filaments are poorly understood. The study of growth kinetics is significant not only to analyze catalyst activity but also to establish the growth mechanisms of coiled carbon filaments. The establishment of growth mechanisms would be useful for determining optimum synthesis conditions and maximizing the quantity of carbon filaments synthesized for a given application. In the first study, tip grown single helical carbon filaments or carbon nanocoils (CNCs) were synthesized by a chemical vapor deposition method using tin-iron-oxide (Sn-Fe-O) xerogel film catalyst. The Sn-Fe-O catalyst was prepared by a low-cost sol-gel method using stannous acetate and ferric acetate as precursors. The growth kinetics of CNCs were monitored by a thermogravimetric analyzer, and the experimental result was correlated using a one-dimensional kinetic model, corresponding to one-dimensional tip growth. In the second study, bidirectionally grown double helical filaments or carbon microcoils (CMCs) were synthesized using a chemical vapor deposition method. CMCs obtained at two reaction temperatures were compared. CMCs

  18. The aerodynamics of wind turbines

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming; Troldborg, Niels

    2013-01-01

    In the paper we present state-of-the-art of research in wind turbine aerodynamics. We start be giving a brief historical review and a survey over aerodynamic research in wind energy. Next, we focus on some recent research results obtained by our wind energy group at Department of Mechanical...... Engineering at DTU. In particular, we show some new results on the classical problem of the ideal rotor and present a series of new results from an on-going research project dealing with the modelling and simulation of turbulent flow structures in the wake behind wind turbines....

  19. High-temperature superconducting magnets and coils from silver-sheathed Bi-2223 tapes

    International Nuclear Information System (INIS)

    Haldar, P.; Hoehn, J.G. Jr.; Motowidlo, L.R.; Balachandran, U.

    1994-01-01

    Long lengths (30 to 100 m) of silver-sheathed Bi-2223 tapes with high critical current density(J c ) were fabricated by the conventional powder-in-tube technique and used to make compact and robust coils by the wind-and-react approach. The tapes were insulated, co-wound in parallel, and heat treated to produce a fused conductor of larger cross section in the form of pancake coils that were stacked in series to make test magnets. The coils and test magnets were characterized at liquid nitrogen (77 K) and liquid helium (4.2 K) temperatures. The highest field generated by the test magnets was 0.36 T at 77 K and 2.6 T at 4.2 K. Progress in the prototype manufacturing of long lengths of HTS tape conductor is also discussed. Lengths of 30 to 100 m are now being made, and 70 m lengths were observed to carry 23 A (J c ∼ 15,000 A/cm 2 ) when immersed in liquid nitrogen

  20. Performance assessment and optimization of the ITER toroidal field coil joints

    Science.gov (United States)

    Rolando, G.; Foussat, A.; Knaster, J.; Ilin, Y.; Nijhuis, A.

    2013-08-01

    The ITER toroidal field (TF) system features eighteen coils that will provide the magnetic field necessary to confine the plasma. Each winding pack is composed of seven double pancakes (DP) connected through praying hands joints. Shaking hands joints are used to interface the terminals of the conductor with the feeder and inter-coil U-shaped bus bars. The feasibility of operating plasma scenarios depends on the ability of the magnets to retain sufficient temperature and current margins. In this respect, the joints represent a possible critical region due to the combination of steady state Joule heating in the resistance of the joint and coupling losses and currents in ramped operation. The temperature and current margins of both DP and terminal joints are analysed during the 15 and 17 MA plasma scenarios. The effect on the joint performance of feasible optimization solutions, such as rotation of the terminal joints and sole RRR increase, is explored. The characterization of the TF coil joints is completed by the estimation of the coupling loss time constant for different inter-strand and strand-to-joint resistance values. The study is carried out with the code JackPot-ACDC, allowing the analysis of lap-type joints with a strand-level detail.

  1. Experimental Manufacture and Performance Evaluation of Linear Switched Reluctance Motor with HTS Excitation Windings

    Science.gov (United States)

    Hirayama, Tadashi; Oto, Satoshi; Higashijima, Atsushi; Kawabata, Shuma

    This paper presents an experimental manufacture and performance evaluation of prototype linear switched reluctance motor with HTS excitation windings (HTS-LSRM). The Ag-alloy sheathed Bi-2223 tapes are used for HTS coils. We first present a structure of the prototype HTS-LSRM. Next, current-carrying properties of the HTS coils are measured. Furthermore, current and voltage waveforms are measured and we evaluation a control performance of the current and voltage.

  2. A low cost light diffuser made of metal coil.

    Science.gov (United States)

    Morita, Nozomi; Arai, Tsunenori

    2008-01-01

    We proposed a low cost flexible light diffuser made of metal coil to obtain an appropriate light dose against certain laser therapies in narrow bending organs. We investigated experimentally the diffusion light dose of prototype coils made of stainless steel (sus304). We measured the diffusion light intensity of the prototype coils along the irradiation direction and the circumferential direction with the various pitch distances of the prototype coils and numerical aperture (NA) of laser light beam as the characteristic parameters of the light diffusion. We measured the temperature elevation of the prototype coils to study the waste energy of these prototype coils. The FWHM on the light intensity along the prototype coils marked up to 12.8mm with the constant pitch distance of 0.09 mm and the fiber output light NA of 0.038. The FWHM on the light intensity was improved to 13.7 mm with the composite pitch distance coils of which the pitch distances were 0.09 mm in the proximate and 0.18 mm in the distal. Since the efficiency of the diffusion irradiation against the fiber output was typically 7.7% in the prototype coils of which the surface reflectance was 50%, approximately 90% of the laser light energy was transferred to the temperature elevation. We estimated the practical diffusion efficiency around 75% using the high reflection of the prototype coils surface up to 90%.

  3. Retrieval of prolapsed coils during endovascular treatment of cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Dinc, Hasan [Karadeniz Technical University, Department of Radiology, Faculty of Medicine, Trabzon (Turkey); KTU Farabi Hospital, Department of Radiology, Trabzon (Turkey); Kuzeyli, Kayhan [Karadeniz Technical University, Department of Neurosurgery, Faculty of Medicine, Trabzon (Turkey); Kosucu, Polat; Sari, Ahmet [Karadeniz Technical University, Department of Radiology, Faculty of Medicine, Trabzon (Turkey); Cekirge, Saruhan [Hacettepe University, Department of Radiology, Faculty of Medicine, Ankara (Turkey)

    2006-04-15

    One of the feared complications during detachable coil embolization of cerebral aneurysms is herniation of a coil loop into the parent artery. Although coil protrusion of one or two loops into the parent vessel may not cause adverse events and in some instances can be ignored, the authors believe that coil retrieval is indicated if a free end is seen pulsating along the blood flow stream to prevent migration of the entire coil mass. In one patient, a microballoon was inflated across the neck of the aneurysm during retrieval of a herniated coil to prevent further coil herniation from the aneurysm sac. We present two cases in which prolapsed coils were successfully retrieved either using a microsnare and balloon combination or a microsnare alone. This report focuses on the efficacy of the Amplatz microsnare for such retrievals and the circumstances in which a herniated coil needs to be retrieved. We report two cases in which embolization coils partially migrated into the parent artery during endovascular treatment of cerebral aneurysm and were retrieved using the Amplatz Nitinol microsnare. (orig.)

  4. Conceptual Design of Alborz Tokamak Poloidal Coils System

    Science.gov (United States)

    Mardani, M.; Amrollahi, R.

    2013-04-01

    The Alborz tokamak is a D-shape cross section tokamak that is under construction in Amirkabir University of Technology. One of the most important parts of tokamak design is the design of the poloidal field system. This part includes the numbers, individual position, currents and number of coil turns of the magnetic field coils. Circular cross section tokamaks have Vertical Field system but since the elongation and triangularity of plasma cross section shaping are important in improving the plasma performance and stability, the poloidal field coils are designed to have a shaped plasma configuration. In this paper the design of vertical field system and the magnetohydrodynamic equilibrium of axisymmetric plasma, as given by the Grad-Shafranov equation will be discussed. The poloidal field coils system consists of 12 circular coils located symmetrically about the equator plane, six inner PF coils and six outer PF coils. Six outer poloidal field coils (PF) are located outside of the toroidal field coils (TF), and six inner poloidal field coils are wound on the inner legs and are located outside of a vacuum vessel.

  5. Transcranial Magnetic Stimulation-coil design with improved focality

    Science.gov (United States)

    Rastogi, P.; Lee, E. G.; Hadimani, R. L.; Jiles, D. C.

    2017-05-01

    Transcranial Magnetic Stimulation (TMS) is a technique for neuromodulation that can be used as a non-invasive therapy for various neurological disorders. In TMS, a time varying magnetic field generated from an electromagnetic coil placed on the scalp is used to induce an electric field inside the brain. TMS coil geometry plays an important role in determining the focality and depth of penetration of the induced electric field responsible for stimulation. Clinicians and basic scientists are interested in stimulating a localized area of the brain, while minimizing the stimulation of surrounding neural networks. In this paper, a novel coil has been proposed, namely Quadruple Butterfly Coil (QBC) with an improved focality over the commercial Figure-8 coil. Finite element simulations were conducted with both the QBC and the conventional Figure-8 coil. The two coil's stimulation profiles were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils has been done to determine the parameters of interest-volume of stimulation, maximum electric field, location of maximum electric field and area of stimulation across all 50 head models for both coils.

  6. Structural analysis of the NET toroidal field coils and conductor

    International Nuclear Information System (INIS)

    Mitchell, N.; Collier, D.; Gori, R.

    1989-01-01

    The NET toroidal field coils will utilise A15-type superconductor at 4.2 K to generate fields up to 11.5 T. The superconductor strands themselves are sensitive to strain, which causes degradation of their current carrying capacity, and thus the detailed behaviour of the coil conductor must be analysied so that the strian can be minimised. This analysis must include the manufacturing processes of the conductor as well as the normal and abnormal loperational loads. The conductor will be insulated and bonded by glass fibre reinforced epoxy resin, with limited bonding shear strength, and the overall support of the complete coil system must be designed to reduce these shear stresses. The coils will be subjected to pulse loads form the poloidal field coils, and analysis of the slip between the various coil components, such as conductors and the coil case, giving rise to frictional heating and possible loss of superconducting properties is another important factor, which has been investigated by a number of stress analyses. The manufacturing, thermal and normal magnetic loads on the coils and the analysis leading to the proposed structural design are described. In addition to the normal operating conditions, there is a range of abnormal load conditions which could result from electrical or mechanical faults on the coils. The effect of these potential faults has been analysed and the coil design modified to prevent catastrophic structural failure. (author). 13 refs.; 8 figs.; 1 tab

  7. Hydrodynamic studies of CNT nanofluids in helical coil heat exchanger

    Science.gov (United States)

    Babita; Sharma, S. K.; Mital Gupta, Shipra; Kumar, Arinjay

    2017-12-01

    Helical coils are extensively used in several industrial processes such as refrigeration systems, chemical reactors, recovery processes etc to accommodate a large heat transfer area within a smaller space. Nanofluids are getting great attention due to their enhanced heat transfer capability. In heat transfer equipments, pressure drop is one of the major factors of consideration for pumping power calculations. So, the present work is aimed to study hydrodynamics of CNT nanofluids in helical coils. In this study, pressure drop characteristics of CNT nanofluid flowing inside horizontal helical coils are investigated experimentally. The helical coil to tube diameter was varied from 11.71 to 27.34 keeping pitch of the helical coil constant. Double distilled water was used as basefluid. SDBS and GA surfactants were added to stablilize CNT nanofluids. The volumetric fraction of CNT nanofluid was varied from 0.003 vol% to 0.051 vol%. From the experimental data, it was analyzed that the friction factor in helical coils is greater than that of straight tubes. Concentration of CNT in nanofluids also has a significant influence on the pressure drop/friction factor of helical coils. At a constant concentration of CNT, decreasing helical coil to tube diameter from 27.24 to 11.71, fanning friction factor of helical coil; f c increases for a constant value of p/d t. This increase in the value of fanning friction factor can be attributed to the secondary flow of CNT nanofluid in helical coils.

  8. Magnetic coil design considerations for functional magnetic stimulation.

    Science.gov (United States)

    Lin, V W; Hsiao, I N; Dhaka, V

    2000-05-01

    Our studies have demonstrated effective stimulation of the bladder, bowel, and expiratory muscles in patients with spinal cord injury using functional magnetic stimulation. However, one limitation of the magnetic coils (MC) is related to their inability to specifically stimulate the target tissue without activation of surrounding tissue. The primary goal of this study was to determine the governing parameters in the MC design, such as coil configuration, diameter, and number of turns in one loop of the coil. By varying these parameters, our approach was to design, construct, and evaluate the induced electric field distributions of two sets of novel MC's. Based on the slinky coil design, the first set of coils was constructed to compare their abilities in generating induced electric fields for focal nerve excitation. The second set of coils was built to determine the effect that changes in two parameters, coil diameter and number of turns in one loop, had on field penetration. The results showed that the slinky coil design produced more focalized stimulation when compared to the planar round coils. The primary-to-secondary peak ratios of the induced electric field from slinky 1 to 5 were 1.00, 2.20, 2.85, 2.62, and 3.54. We also determined that coils with larger diameters had better penetration than those with smaller diameters. Coils with less number of turns in one loop had higher initial field strengths; when compared to coils that had more turns per loop, initial field strengths remained higher as distance from the coil increased. In our attempt to customize MC design according to each functional magnetic stimulation application and patients of different sizes, the parameters of MC explored in this study may facilitate designing an optimal MC for a certain clinical application.

  9. Bending of the BST-2 coiled-coil during viral budding.

    Science.gov (United States)

    Ozcan, Kadir A; Berndsen, Christopher E

    2017-11-01

    BST-2/tetherin is a human extracellular transmembrane protein that serves as a host defense factor against HIV-1 and other viruses by inhibiting viral spreading. Structurally, BST-2 is a homo-dimeric coiled-coil that is connected to the host cell membrane by N and C terminal transmembrane anchors. The C-terminal membrane anchor of BST-2 is inserted into the budding virus while the N-terminal membrane anchor remains in the host cell membrane creating a viral tether. The structural mechanism of viral budding and tethering as mediated by BST-2 is not clear. To more fully describe the mechanism of viral tethering, we created a model of BST-2 embedded in a membrane and used steered molecular dynamics to simulate the transition from the host cell membrane associated form to the cell-virus membrane bridging form. We observed that BST-2 did not transition as a rigid structure, but instead bent at positions with a reduced interface between the helices of the coiled-coil. The simulations for the human BST-2 were then compared with simulations on the mouse homolog, which has no apparent weak spots. We observed that the mouse homolog spread the bending across the ectodomain, rather than breaking at discrete points as observed with the human homolog. These simulations support previous biochemical and cellular work suggesting some flexibility in the coiled-coil is necessary for viral tethering, while also highlighting how subtle changes in protein sequence can influence the dynamics and stability of proteins with overall similar structure. © 2017 Wiley Periodicals, Inc.

  10. 78 FR 29364 - Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4...

    Science.gov (United States)

    2013-05-20

    ...-005, QF07-257-004] Exelon Corporation, Exelon Wind 1, LLC, Exelon Wind 2, LLC, Exelon Wind 3, LLC, Exelon Wind 4, LLC, Exelon Wind 5, LLC, Exelon Wind 6, LLC, Exelon Wind 7, LLC, Exelon Wind 8, LLC, Exelon Wind 9, LLC, Exelon Wind 10, LLC, Exelon Wind 11, LLC, High Plains Wind Power, LLC v. Xcel Energy...

  11. Yttrium-90 Resin Microsphere Radioembolization Using an Antireflux Catheter: An Alternative to Traditional Coil Embolization for Nontarget Protection

    Energy Technology Data Exchange (ETDEWEB)

    Morshedi, Maud M., E-mail: maud.morshedi@my.rfums.org; Bauman, Michael, E-mail: mbauman@ucsd.edu; Rose, Steven C., E-mail: scrose@ucsd.edu; Kikolski, Steven G., E-mail: skikolski@gmail.com [University of California San Diego Health Sciences, Radiology Department, University of California San Diego Medical Center (United States)

    2015-04-15

    PurposeSerious complications can result from nontarget embolization during yttrium-90 (Y-90) transarterial radioembolization. Hepatoenteric artery coil embolization has been traditionally performed to prevent nontarget radioembolization. The U.S. Food and Drug Administration–approved Surefire Infusion System (SIS) catheter, designed to prevent reflux, is an alternative to coils. The hypothesis that quantifiable SIS procedural parameters are comparable to coil embolization was tested.MethodsFourteen patients aged 36–79 years with colorectal, neuroendocrine, hepatocellular, and other predominantly bilobar hepatic tumors who underwent resin microsphere Y-90 radioembolization using only the SIS catheter (n = 7) versus only detachable coils (n = 7) for nontarget protection were reviewed retrospectively. Procedure time, fluoroscopy time, contrast dose, radiation dose, and cost were evaluated.ResultsMultivariate analysis identified significant cohort differences in the procedural parameters evaluated (F(10, 3) = 10.39, p = 0.04). Between-group comparisons of the pretreatment planning procedure in the SIS catheter group compared to the coil embolization group demonstrated a significant reduction in procedure time (102.6 vs. 192.1 min, respectively, p = 0.0004), fluoroscopy time (14.3 vs. 49.7 min, respectively, p = 0.0016), and contrast material dose (mean dose of 174.3 vs. 265.0 mL, respectively, p = 0.0098). Procedural parameters were not significantly different between the two groups during subsequent dose delivery procedures. Overall cost of combined first-time radioembolization procedures was significantly less in the SIS group ($4252) compared to retrievable coil embolization ($11,123; p = 0.001).ConclusionThe SIS catheter results in a reduction in procedure time, fluoroscopy time, and contrast material dose and may be an attractive cost-effective alternative to detachable coil embolization for prevention of nontarget radioembolization.

  12. Coil Migration after Transarterial Coil Embolization of a Splenic Artery Pseudoaneurysm

    Directory of Open Access Journals (Sweden)

    Bezawit D. Tekola

    2013-11-01

    Full Text Available A 48-year-old man with a history of splenic artery pseudoaneurysm requiring transarterial embolization 3 months earlier presented to the emergency department with abdominal pain and fever. Computed tomography showed evidence of embolization coil fragments within the gastrointestinal tract. Upper endoscopy showed a large gastric ulcer with numerous embolization coils extruding into the gastric lumen. The patient underwent partial gastrectomy, distal pancreatectomy and resection of the splenic artery pseudoaneurysm. This case illustrates a rare delayed complication of transarterial embolization of a splenic artery pseudoaneurysm.

  13. Polymer therapeutics with a coiled coil motif targeted against murine BCL1 leukemia

    Czech Academy of Sciences Publication Activity Database

    Pola, Robert; Laga, Richard; Ulbrich, Karel; Sieglová, Irena; Král, Vlastimil; Fábry, Milan; Kabešová, Martina; Kovář, Marek; Pechar, Michal

    2013-01-01

    Roč. 14, č. 3 (2013), s. 881-889 ISSN 1525-7797 R&D Projects: GA ČR GAP301/11/0325; GA AV ČR IAAX00500803 Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:61389013 ; RVO:61388971 ; RVO:68378050 Keywords : coiled coil * polymer therapeutics * scFv Subject RIV: CD - Macromolecular Chemistry; EC - Immunology (MBU-M); EB - Genetics ; Molecular Biology (UMG-J) Impact factor: 5.788, year: 2013

  14. Polymer cancerostatics with a coiled coil motif targeted against murine leukemia

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Pola, Robert; Janoušková, Olga; Sieglová, Irena; Král, Vlastimil; Fábry, Milan; Tomalová, Barbora; Kovář, Marek

    2017-01-01

    Roč. 6, 4 (Suppl) (2017), s. 36 ISSN 2325-9604. [International Conference and Exhibition on Nanomedicine and Drug Delivery. 29.05.2017-31.05.2017, Osaka] R&D Projects: GA ČR(CZ) GA16-17207S Institutional support: RVO:61389013 ; RVO:68378050 ; RVO:61388971 Keywords : coiled coil * polymer cancerostatics * active targeting Subject RIV: CD - Macromolecular Chemistry; EC - Immunology (MBU-M) https://www.scitechnol.com/conference-abstracts/scientific-tracks-abstracts/nanodelivery-2017-proceedings.html

  15. The heterotrimeric laminin coiled-coil domain exerts anti-adhesive effects and induces a pro-invasive phenotype.

    Directory of Open Access Journals (Sweden)

    Patricia Santos-Valle

    Full Text Available Laminins are large heterotrimeric cross-shaped extracellular matrix glycoproteins with terminal globular domains and a coiled-coil region through which the three chains are assembled and covalently linked. Laminins are key components of basement membranes, and they serve as attachment sites for cell adhesion, migration and proliferation. In this work, we produced a recombinant fragment comprising the entire laminin coiled-coil of the α1-, β1-, and γ1-chains that assemble into a stable heterotrimeric coiled-coil structure independently of the rest of the molecule. This domain was biologically active and not only failed to serve as a substrate for cell attachment, spreading and focal adhesion formation but also inhibited cell adhesion to laminin when added to cells in a soluble form at the time of seeding. Furthermore, gene array expression profiling in cells cultured in the presence of the laminin coiled-coil domain revealed up-regulation of genes involved in cell motility and invasion. These findings were confirmed by real-time quantitative PCR and zymography assays. In conclusion, this study shows for the first time that the laminin coiled-coil domain displays anti-adhesive functions and has potential implications for cell migration during matrix remodeling.

  16. Crystal Structure of the Central Coiled-Coil Domain from Human Liprin-β2†,‡

    Science.gov (United States)

    Stafford, Ryan L.; Tang, Ming-Yun; Sawaya, Michael R.; Phillips, Martin L.; Bowie, James U.

    2011-01-01

    Liprins are a conserved family of scaffolding proteins important for the proper regulation and development of neuronal synapses. Humans have four liprin-αs and two liprin-βs which all contain long coiled-coil domains followed by three tandem SAM domains. Complex interactions between the coiled-coil and SAM domains are thought to create liprin scaffolds, but the structural and biochemical properties of these domains remain largely uncharacterized. In this study we find that the human liprin-β2 coiled-coil forms an extended dimer. Several protease-resistant sub-domains within the liprin-β1 and liprin-β2 coiled-coils were also identified. A 2.0 Å crystal structure of the central, protease-resistant core of the liprin-β2 coiled-coil reveals a parallel helix orientation. These studies represent an initial step towards determining the overall architecture of liprin scaffolds and understanding the molecular basis for their synaptic functions. PMID:21462929

  17. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  18. Feasibility study of 5MW superconducting wind turbine generator

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Jensen, Bogi Bech; Seiler, E.

    2011-01-01

    The feasibility of installing a direct drive superconducting generator in the 5MW reference offshore wind turbine of the National Renewable Energy Laboratory (NREL) has been examined. The engineering current densities Je obtained in a series of race track coils have been combined with magnetization...... measurements to estimate the properties of suitable field coils for a synchronous generator, which is more light weight than the conventional used combination of a gear box and a fast rotating generator. An analytical model and finite element simulations have been used to estimate the active mass of generators...

  19. Reminiscences on the study of wind waves.

    Science.gov (United States)

    Mitsuyasu, Hisashi

    2015-01-01

    The wind blowing over sea surface generates tiny wind waves. They develop with time and space absorbing wind energy, and become huge wind waves usually referred to ocean surface waves. The wind waves cause not only serious sea disasters but also take important roles in the local and global climate changes by affecting the fluxes of momentum, heat and gases (e.g. CO2) through the air-sea boundary. The present paper reviews the selected studies on wind waves conducted by our group in the Research Institute for Applied Mechanics (RIAM), Kyushu University. The themes discussed are interactions between water waves and winds, the energy spectrum of wind waves, nonlinear properties of wind waves, and the effects of surfactant on some air-sea interaction phenomena.

  20. Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms.

    Directory of Open Access Journals (Sweden)

    Anna L Hoppe

    Full Text Available In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism. We test the hypothesis that aneurysm growth is the primary recurrence mechanism. We also test the hypothesis that the coil mass will translate a measurable extent when recurrence occurs.An objective, quantitative image analysis protocol was developed to determine the volumes of aneurysms and coil masses during initial and follow-up visits from 3D rotational angiograms. The population consisted of 15 recurrence and 12 non-recurrence control aneurysms initially completely coiled at a single center. An investigator sensitivity study was performed to assess the objectivity of the methods. Paired Wilcoxon tests (p<0.05, one-tailed were performed to assess for aneurysm and coil growth. The translation of the coil mass center at follow-up was computed. A Mann Whitney U-Test (p<0.05, one-tailed was used to compare translation of coil mass centers between recurrence and control subjects.Image analysis protocol was found to be insensitive to the investigator. Aneurysm growth was evident in the recurrence cohort (p=0.003 but not the control (p=0.136. There was no evidence of coil compaction in either the recurrence or control cohorts (recurrence: p=0.339; control: p=0.429. The translation of the coil mass centers was found to be significantly larger in the recurrence cohort than the control cohort (p=0.047.Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization. The coil mass likely translates to a measurable extent when recurrence occurs and has the potential to serve as a non-angiographic recurrence marker.