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Sample records for acidic coiled coil

  1. Repeats in transforming acidic coiled-coil (TACC) genes.

    Science.gov (United States)

    Trivedi, Seema

    2013-06-01

    Transforming acidic coiled-coil proteins (TACC1, 2, and 3) are essential proteins associated with the assembly of spindle microtubules and maintenance of bipolarity. Dysregulation of TACCs is associated with tumorigenesis, but studies of microsatellite instability in TACC genes have not been extensive. Microsatellite or simple sequence repeat instability is known to cause many types of cancer. The present in silico analysis of SSRs in human TACC gene sequences shows the presence of mono- to hexa-nucleotide repeats, with the highest densities found for mono- and di-nucleotide repeats. Density of repeats is higher in introns than in exons. Some of the repeats are present in regulatory regions and retained introns. Human TACC genes show conservation of many repeat classes. Microsatellites in TACC genes could be valuable markers for monitoring numerical chromosomal aberrations and or cancer.

  2. 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

    2016-04-01

    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.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

  3. A classic zinc finger from friend of GATA mediates an interaction with the coiled-coil of transforming acidic coiled-coil 3.

    Science.gov (United States)

    Simpson, Raina J Y; Yi Lee, Stella Hoi; Bartle, Natalie; Sum, Eleanor Y; Visvader, Jane E; Matthews, Jacqueline M; Mackay, Joel P; Crossley, Merlin

    2004-09-17

    Classic zinc finger domains (cZFs) consist of a beta-hairpin followed by an alpha-helix. They are among the most abundant of all protein domains and are often found in tandem arrays in DNA-binding proteins, with each finger contributing an alpha-helix to effect sequence-specific DNA recognition. Lone cZFs, not found in tandem arrays, have been postulated to function in protein interactions. We have studied the transcriptional co-regulator Friend of GATA (FOG), which contains nine zinc fingers. We have discovered that the third cZF of FOG contacts a coiled-coil domain in the centrosomal protein transforming acidic coiled-coil 3 (TACC3). Although FOG-ZF3 exhibited low solubility, we have used a combination of mutational mapping and protein engineering to generate a derivative that was suitable for in vitro and structural analysis. We report that the alpha-helix of FOG-ZF3 recognizes a C-terminal portion of the TACC3 coiled-coil. Remarkably, the alpha-helical surface utilized by FOG-ZF3 is the same surface responsible for the well established sequence-specific DNA-binding properties of many other cZFs. Our data demonstrate the versatility of cZFs and have implications for the analysis of many as yet uncharacterized cZF proteins.

  4. 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

    2016-01-15

    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.

  5. Random-coil chemical shifts of phosphorylated amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Bienkiewicz, Ewa A.; Lumb, Kevin J. [Colorado State University, Department of Biochemistry and Molecular Biology (United States)

    1999-11-15

    The {sup 1}H, {sup 13}C, {sup 15}N and {sup 31} P random-coil chemical shifts and phosphate pK{sub a} values of the phosphorylated amino acids pSer, pThr and pTyr in the protected peptide Ac-Gly-Gly-X-Gly-Gly-NH{sub 2} have been obtained in water at 25 deg. C over the pH range 2 to 9. Analysis of ROESY spectra indicates that the peptides are unstructured. Phosphorylation induces changes in random-coil chemical shifts, some of which are comparable to those caused by secondary structure formation, and are therefore significant in structural analyses based on the chemical shift.

  6. 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.

  7. Designing Stable Antiparallel Coiled Coil Dimers

    Institute of Scientific and Technical Information of China (English)

    曾宪纲; 周海梦

    2001-01-01

    The history of antiparallel coiled coil dimer design is briefly reviewed and the main principles governing the successful designs are explained. They include analysis of the inter-subunit electrostatic repulsion for determining partners for dimerization and of the buried polar interaction for determining the relative orientation of the partners. A theory is proposed to explain the lack of antiparallel coiled coil homodimers in nature.

  8. Coil Welding Aid

    Science.gov (United States)

    Wiesenbach, W. T.; Clark, M. C.

    1983-01-01

    Positioner holds coil inside cylinder during tack welding. Welding aid spaces turns of coil inside cylinder and applies contact pressure while coil is tack-welded to cylinder. Device facilitates fabrication of heat exchangers and other structures by eliminating hand-positioning and clamping of individual coil turns.

  9. Starfire poloidal coil systems

    Energy Technology Data Exchange (ETDEWEB)

    Evans, K. Jr.; Kim, S.H.; Turner, L.R.; Wang, S.T.

    1980-01-01

    The poloidal coils for STARFIRE consists of three systems: (1) equilibrium field (EF) coils; (2) ohmic heating (OH) coils; and (3) correction field (CF) coils. The EF coils are superconducting and lie outside the toroidal field (TF) coils. These coils provide the bulk of the equilibrium field necessary to keep the plasma positioned in the vacuum chamber with the desired cross sectional shape and pressure and current distributions. Having these coils outside of the TF coils requires that they have a larger stored energy and larger currents but eases the assembly, maintenance, and reliability of the coils. The STARFIRE OH system is relatively small compared to tokamaks in which the current is entirely ohmically driven. It is designed to provide sufficient flux in the early startup to raise the plasma current to the point (1 to 2 MA) where the rf current drive can take over.

  10. Acidic pH triggers conformational changes at the NH2-terminal propeptide of the precursor of pulmonary surfactant protein B to form a coiled coil structure.

    Science.gov (United States)

    Bañares-Hidalgo, A; Pérez-Gil, J; Estrada, P

    2014-07-01

    Pulmonary surfactant protein SP-B is synthesized as a larger precursor, proSP-B. We report that a recombinant form of human SP-BN forms a coiled coil structure at acidic pH. The protonation of a residue with pK=4.8±0.06 is the responsible of conformational changes detected by circular dichroism and intrinsic fluorescence emission. Sedimentation velocity analysis showed protein oligomerisation at any pH condition, with an enrichment of the species compatible with a tetramer at acidic pH. Low 2,2,2,-trifluoroethanol concentration promoted β-sheet structures in SP-BN, which bind Thioflavin T, at acidic pH, whereas it promoted coiled coil structures at neutral pH. The amino acid stretch predicted to form β-sheet parallel association in SP-BN overlaps with the sequence predicted by several programs to form coiled coil structure. A synthetic peptide ((60)W-E(85)) designed from the sequence of the amino acid stretch of SP-BN predicted to form coiled coil structure showed random coil conformation at neutral pH but concentration-dependent helical structure at acidic pH. Sedimentation velocity analysis of the peptide indicated monomeric state at neutral pH (s20, w=0.55S; Mr~3kDa) and peptide association (s20, w=1.735S; Mr=~14kDa) at acidic pH, with sedimentation equilibrium fitting to a Monomer-Nmer-Mmer model with N=6 and M=4 (Mr=14692Da). We propose that protein oligomerisation through coiled-coil motifs could then be a general feature in the assembly of functional units in saposin-like proteins in general and in the organization of SP-B in a functional surfactant, in particular. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Protective link for superconducting coil

    Science.gov (United States)

    Umans, Stephen D.

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  12. Insights on the structure and stability of Licanantase: a trimeric acid-stable coiled-coil lipoprotein from Acidithiobacillus thiooxidans

    Directory of Open Access Journals (Sweden)

    Fernando Abarca

    2014-08-01

    Full Text Available Licanantase (Lic is the major component of the secretome of Acidithiobacillus thiooxidans when grown in elemental sulphur. When used as an additive, Lic improves copper recovery from bioleaching processes. However, this recovery enhancement is not fully understood. In this context, our aim is to predict the 3D structure of Lic, to shed light on its structure-function relationships. Bioinformatics analyses on the amino acid sequence of Lic showed a great similarity with Lpp, an Escherichia coli Lipoprotein that can form stable trimers in solution. Lic and Lpp share the secretion motif, intracellular processing and alpha helix structure, as well as the distribution of hydrophobic residues in heptads forming a hydrophobic core, typical of coiled-coil structures. Cross-linking experiments showed the presence of Lic trimers, supporting our predictions. Taking the in vitro and in silico evidence as a whole, we propose that the most probable structure for Lic is a trimeric coiled-coil. According to this prediction, a suitable model for Lic was produced using the de novo algorithm “Rosetta Fold-and-Dock”. To assess the structural stability of our model, Molecular Dynamics (MD and Replica Exchange MD simulations were performed using the structure of Lpp and a 14-alanine Lpp mutant as controls, at both acidic and neutral pH. Our results suggest that Lic was the most stable structure among the studied proteins in both pH conditions. This increased stability can be explained by a higher number of both intermonomer hydrophobic contacts and hydrogen bonds, key elements for the stability of Lic’s secondary and tertiary structure.

  13. Insights on the structure and stability of Licanantase: a trimeric acid-stable coiled-coil lipoprotein from Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Abarca, Fernando; Gutierrez-Maldonado, Sebastian E; Parada, Pilar; Martinez, Patricio; Maass, Alejandro; Perez-Acle, Tomas

    2014-01-01

    Licanantase (Lic) is the major component of the secretome of Acidithiobacillus thiooxidans when grown in elemental sulphur. When used as an additive, Lic improves copper recovery from bioleaching processes. However, this recovery enhancement is not fully understood. In this context, our aim is to predict the 3D structure of Lic, to shed light on its structure-function relationships. Bioinformatics analyses on the amino acid sequence of Lic showed a great similarity with Lpp, an Escherichia coli Lipoprotein that can form stable trimers in solution. Lic and Lpp share the secretion motif, intracellular processing and alpha helix structure, as well as the distribution of hydrophobic residues in heptads forming a hydrophobic core, typical of coiled-coil structures. Cross-linking experiments showed the presence of Lic trimers, supporting our predictions. Taking the in vitro and in silico evidence as a whole, we propose that the most probable structure for Lic is a trimeric coiled-coil. According to this prediction, a suitable model for Lic was produced using the de novo algorithm "Rosetta Fold-and-Dock". To assess the structural stability of our model, Molecular Dynamics (MD) and Replica Exchange MD simulations were performed using the structure of Lpp and a 14-alanine Lpp mutant as controls, at both acidic and neutral pH. Our results suggest that Lic was the most stable structure among the studied proteins in both pH conditions. This increased stability can be explained by a higher number of both intermonomer hydrophobic contacts and hydrogen bonds, key elements for the stability of Lic's secondary and tertiary structure.

  14. Dual coil ignition system

    Energy Technology Data Exchange (ETDEWEB)

    Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

    2017-03-28

    A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

  15. Coil system for plasmoid thruster

    Science.gov (United States)

    Eskridge, Richard H. (Inventor); Lee, Michael H. (Inventor); Martin, Adam K. (Inventor); Fimognari, Peter J. (Inventor)

    2010-01-01

    A coil system for a plasmoid thruster includes a bias coil, a drive coil and field coils. The bias and drive coils are interleaved with one another as they are helically wound about a conical region. A first field coil defines a first passage at one end of the conical region, and is connected in series with the bias coil. A second field coil defines a second passage at an opposing end of the conical region, and is connected in series with the bias coil.

  16. Liquid rope coiling

    NARCIS (Netherlands)

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

    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 (visco

  17. Methods for Solving Highly Symmetric De Novo Designed Metalloproteins: Crystallographic Examination of a Novel Three-Stranded Coiled-Coil Structure Containing d-Amino Acids.

    Science.gov (United States)

    Ruckthong, L; Stuckey, J A; Pecoraro, V L

    2016-01-01

    The core objective of de novo metalloprotein design is to define metal-protein relationships that control the structure and function of metal centers by using simplified proteins. An essential requirement to achieve this goal is to obtain high resolution structural data using either NMR or crystallographic studies in order to evaluate successful design. X-ray crystal structures have proven that a four heptad repeat scaffold contained in the three-stranded coiled coil (3SCC), called CoilSer (CS), provides an excellent motif for modeling a three Cys binding environment capable of chelating metals into geometries that resemble heavy metal sites in metalloregulatory systems. However, new generations of more complicated designs that feature, for example, a d-amino acid or multiple metal ligand sites in the helical sequence require a more stable construct. In doing so, an extra heptad was introduced into the original CS sequence, yielding a GRAND-CoilSer (GRAND-CS) to retain the 3SCC folding. An apo-(GRAND-CSL12DLL16C)3 crystal structure, designed for Cd(II)S3 complexation, proved to be a well-folded parallel 3SCC. Because this structure is novel, protocols for crystallization, structural determination, and refinements of the apo-(GRAND-CSL12DLL16C)3 are described. This report should be generally useful for future crystallographic studies of related coiled-coil designs.

  18. Optimal Bitter Coil Solenoid

    CERN Document Server

    Kobelev, V

    2016-01-01

    Bitter coil is an electromagnet used for the generation of exceptionally strong magnetic fields. The upper bound of magnet flux density is restricted by several factors. One principal restriction is the high stresses due to Lorentz forces in the coil. The Lorentz forces generate the distributed body force, which acts as the pressure of magnetic field. The common radial thickness profile of the Bitter coil is constant. In this paper the possibility of optimization by means of non-constant radial thickness profile of the Bitter coil is studied. The close form expression for optimal thickness profile is obtained. Both designs are compared and the considerable improvement of magnetic flux density is demonstrated. Moreover, the optimal design improves the shape of cooling channels. Namely, the highest cross-section of cooling channel is at the most thermally loaded inner surface of the coil.

  19. Coiled-coil protein composition of 22 proteomes – differences and common themes in subcellular infrastructure and traffic control

    Directory of Open Access Journals (Sweden)

    Meier Iris

    2005-11-01

    Full Text Available Abstract Background Long alpha-helical coiled-coil proteins are involved in diverse organizational and regulatory processes in eukaryotic cells. They provide cables and networks in the cyto- and nucleoskeleton, molecular scaffolds that organize membrane systems and tissues, motors, levers, rotating arms, and possibly springs. Mutations in long coiled-coil proteins have been implemented in a growing number of human diseases. Using the coiled-coil prediction program MultiCoil, we have previously identified all long coiled-coil proteins from the model plant Arabidopsis thaliana and have established a searchable Arabidopsis coiled-coil protein database. Results Here, we have identified all proteins with long coiled-coil domains from 21 additional fully sequenced genomes. Because regions predicted to form coiled-coils interfere with sequence homology determination, we have developed a sequence comparison and clustering strategy based on masking predicted coiled-coil domains. Comparing and grouping all long coiled-coil proteins from 22 genomes, the kingdom-specificity of coiled-coil protein families was determined. At the same time, a number of proteins with unknown function could be grouped with already characterized proteins from other organisms. Conclusion MultiCoil predicts proteins with extended coiled-coil domains (more than 250 amino acids to be largely absent from bacterial genomes, but present in archaea and eukaryotes. The structural maintenance of chromosomes proteins and their relatives are the only long coiled-coil protein family clearly conserved throughout all kingdoms, indicating their ancient nature. Motor proteins, membrane tethering and vesicle transport proteins are the dominant eukaryote-specific long coiled-coil proteins, suggesting that coiled-coil proteins have gained functions in the increasingly complex processes of subcellular infrastructure maintenance and trafficking control of the eukaryotic cell.

  20. 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.

  1. 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.

  2. 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.

  3. Coiling of yield stress fluids

    NARCIS (Netherlands)

    Y. Rahmani; M. Habibi; A. Javadi; D. Bonn

    2011-01-01

    We present an experimental investigation of the coiling of a filament of a yield stress fluid falling on a solid surface. We use two kinds of yield stress fluids, shaving foam and hair gel, and show that the coiling of the foam is similar to the coiling of an elastic rope. Two regimes of coiling (el

  4. Linear Rogowski coil

    Science.gov (United States)

    Nassisi, V.; Delle Side, D.

    2017-02-01

    Nowadays, the employment and development of fast current pulses require sophisticated systems to perform measurements. Rogowski coils are used to diagnose cylindrical shaped beams; therefore, they are designed and built with a toroidal structure. Recently, to perform experiments of radiofrequency biophysical stresses, flat transmission lines have been developed. Therefore, in this work we developed a linear Rogowski coil to detect current pulses inside flat conductors. The system is first approached by means of transmission line theory. We found that, if the pulse width to be diagnosed is comparable with the propagation time of the signal in the detector, it is necessary to impose a uniform current as input pulse, or to use short coils. We further analysed the effect of the resistance of the coil and the influence of its magnetic properties. As a result, the device we developed is able to record pulses lasting for some hundreds of nanoseconds, depending on the inductance, load impedance, and resistance of the coil. Furthermore, its response is characterized by a sub-nanosecond rise time (˜100 ps). The attenuation coefficient depends mainly on the turn number of the coil, while the fidelity of the response depends both on the magnetic core characteristics and on the current distribution along the plane conductors.

  5. Flow Injection Analysis of Acid and Base using Thermo-Sensitive Resistance Coils

    OpenAIRE

    1995-01-01

    A flow injection analysis of acid-base by detecting neutralization heat is proposed. A injected sample (acid or base), combined with a carrier (deionized water), was mixed with a reagent (base or acid) stream. A change in the solution temperature was detected by passing the solution, immediately after mixing, through a stainless steel capillary tube around which a thermo-sensitive resistance was coiled. The temperature of carrier was used as a reference Hydrochloric acid solutions of 0.003 to...

  6. Coiled coils and SAH domains in cytoskeletal molecular motors.

    Science.gov (United States)

    Peckham, Michelle

    2011-10-01

    Cytoskeletal motors include myosins, kinesins and dyneins. Myosins move along tracks of actin filaments, whereas kinesins and dyneins move along microtubules. Many of these motors are involved in trafficking cargo in cells. However, myosins are mostly monomeric, whereas kinesins are mostly dimeric, owing to the presence of a coiled coil. Some myosins (myosins 6, 7 and 10) contain an SAH (single α-helical) domain, which was originally thought to be a coiled coil. These myosins are now known to be monomers, not dimers. The differences between SAH domains and coiled coils are described and the potential roles of SAH domains in molecular motors are discussed.

  7. 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

  8. 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.

  9. 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 BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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

  10. Transport vesicle tethering at the trans Golgi network: coiled coil proteins in action

    Directory of Open Access Journals (Sweden)

    Pak-yan Patricia Cheung

    2016-03-01

    Full Text Available 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. 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 towards understanding these questions and remaining, unresolved mysteries will be discussed.

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

    Science.gov (United States)

    Ramos, Jorge; Lazaridis, Themis

    2011-11-01

    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.

  12. Planar, monolithically integrated coil

    NARCIS (Netherlands)

    Roozeboom, F.; Reefman, D.; Klootwijk, J.H.; Tiemeijer, L.F.; Ruigrok, J.

    2013-01-01

    The present invention provides a means to integrate planar coils on silicon, while providing a high inductance. This high inductance is achieved through a special back- and front sided shielding of a material. In many applications, high-value inductors are a necessity. In particular, this holds for

  13. An orientable search coil

    Science.gov (United States)

    Holt, P. J.; Poblocki, M.

    2017-01-01

    We provide a design for a low cost orientable search coil that can be used to investigate the variation of magnetic flux with angle. This experiment is one of the required practical activities in the current A level physics specification for the AQA examination board in the UK. We demonstrate its performance and suggest other suitable investigations that can be undertaken.

  14. Minimax Current Density Coil Design

    CERN Document Server

    Poole, Michael; Lopez, Hector Sanchez; Ng, Michael; Crozier, Stuart; 10.1088/0022-3727/43/9/095001

    2010-01-01

    'Coil design' is an inverse problem in which arrangements of wire are designed to generate a prescribed magnetic field when energized with electric current. The design of gradient and shim coils for magnetic resonance imaging (MRI) are important examples of coil design. The magnetic fields that these coils generate are usually required to be both strong and accurate. Other electromagnetic properties of the coils, such as inductance, may be considered in the design process, which becomes an optimization problem. The maximum current density is additionally optimized in this work and the resultant coils are investigated for performance and practicality. Coils with minimax current density were found to exhibit maximally spread wires and may help disperse localized regions of Joule heating. They also produce the highest possible magnetic field strength per unit current for any given surface and wire size. Three different flavours of boundary element method that employ different basis functions (triangular elements...

  15. Introduction to COIL

    OpenAIRE

    Kane, David

    2008-01-01

    By reciprocal arrangement between WIT and the National College of Ireland, you are now able to access their collection directly - more than 100,000 items. This form of direct consortial borrowing has never been tried before in Ireland. Before you borrow your first book, you will have to set up a COIL account, which is straightforward. The items which you reserve online will be posted to us, for you to collect, at the front desk in the Luke Wadding library, afterwards. The Initiat...

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    Daqi Tu

    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.

  19. Nuclear Magnetic Resonance Structures of GCN4p Are Largely Conserved When Ion Pairs Are Disrupted at Acidic pH but Show a Relaxation of the Coiled Coil Superhelix.

    Science.gov (United States)

    Kaplan, Anne R; Brady, Megan R; Maciejewski, Mark W; Kammerer, Richard A; Alexandrescu, Andrei T

    2017-03-21

    To understand the roles ion pairs play in stabilizing coiled coils, we determined nuclear magnetic resonance structures of GCN4p at three pH values. At pH 6.6, all acidic residues are fully charged; at pH 4.4, they are half-charged, and at pH 1.5, they are protonated and uncharged. The α-helix monomer and coiled coil structures of GCN4p are largely conserved, except for a loosening of the coiled coil quaternary structure with a decrease in pH. Differences going from neutral to acidic pH include (i) an unwinding of the coiled coil superhelix caused by the loss of interchain ion pair contacts, (ii) a small increase in the separation of the monomers in the dimer, (iii) a loosening of the knobs-into-holes packing motifs, and (iv) an increased separation between oppositely charged residues that participate in ion pairs at neutral pH. Chemical shifts (HN, N, C', Cα, and Cβ) of GCN4p display a seven-residue periodicity that is consistent with α-helical structure and is invariant with pH. By contrast, periodicity in hydrogen exchange rates at neutral pH is lost at acidic pH as the exchange mechanism moves into the EX1 regime. On the basis of (1)H-(15)N nuclear Overhauser effect relaxation measurements, the α-helix monomers experience only small increases in picosecond to nanosecond backbone dynamics at acidic pH. By contrast, (13)C rotating frame T1 relaxation (T1ρ) data evince an increase in picosecond to nanosecond side-chain dynamics at lower pH, particularly for residues that stabilize the coiled coil dimerization interface through ion pairs. The results on the structure and dynamics of GCNp4 over a range of pH values help rationalize why a single structure at neutral pH poorly predicts the pH dependence of the unfolding stability of the coiled coil.

  20. 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.

  1. 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...... tools are available for predicting coiled-coil domains in protein sequences, including those based on position-specific score matrices and machine learning methods. RESULTS: In this article, we introduce a hidden Markov model (CCHMM_PROF) that exploits the information contained in multiple sequence...... alignments (profiles) to predict coiled-coil regions. The new method discriminates coiled-coil sequences with an accuracy of 97% and achieves a true positive rate of 79% with only 1% of false positives. Furthermore, when predicting the location of coiled-coil segments in protein sequences, the method reaches...

  2. Coiled-coil conformation of a pentamidine-DNA complex.

    Science.gov (United States)

    Moreno, Tadeo; Pous, Joan; Subirana, Juan A; Campos, J Lourdes

    2010-03-01

    The coiled-coil structure formed by the complex of the DNA duplex d(ATATATATAT)(2) with pentamidine is presented. The duplex was found to have a mixed structure containing Watson-Crick and Hoogsteen base pairs. The drug stabilizes the coiled coil through the formation of cross-links between neighbouring duplexes. The central part of the drug is found in the minor groove as expected, whereas the charged terminal amidine groups protrude and interact with phosphates from neighbouring molecules. The formation of cross-links may be related to the biological effects of pentamidine, which is used as an antiprotozoal agent in trypanosomiasis, leishmaniasis and pneumonias associated with AIDS. The DNA sequence that was used is highly abundant in most eukaryotic genomes. However, very few data are available on DNA sequences which only contain A.T base pairs.

  3. Can Magnetic Coil Ease Tinnitus?

    Science.gov (United States)

    ... Research Updates Technology Horizons Can magnetic coil ease tinnitus? VA trial aims to find out February 3, ... pain. See, for example, this 2009 review study . Tinnitus and Veterans Tinnitus has been one of the ...

  4. 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).

  5. Adjustable Induction-Heating Coil

    Science.gov (United States)

    Ellis, Rod; Bartolotta, Paul

    1990-01-01

    Improved design for induction-heating work coil facilitates optimization of heating in different metal specimens. Three segments adjusted independently to obtain desired distribution of temperature. Reduces time needed to achieve required temperature profiles.

  6. 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.

  7. 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.

  8. HELMHOLTZ COILS FOR MEASURING MAGNETIC MOMENTS

    Directory of Open Access Journals (Sweden)

    P. N. Dobrodeyev

    2013-01-01

    Full Text Available The optimal configuration of the double Helmholtz coils for measuring of the magnetic dipole moments was defined. It was determined that measuring coils should have round shape and compensative coils – the square one. Analytically confirmed the feasibility of the proposed configuration of these coils as primary transmitters of magnetic dipole moments.

  9. Growth Factor Tethering to Protein Nanoparticles via Coiled-Coil Formation for Targeted Drug Delivery.

    Science.gov (United States)

    Assal, Yasmine; Mizuguchi, Yoshinori; Mie, Masayasu; Kobatake, Eiry

    2015-08-19

    Protein-based nanoparticles are attractive carriers for drug delivery because they are biodegradable and can be genetically designed. Moreover, modification of protein-based nanoparticles with cell-specific ligands allows for active targeting abilities. Previously, we developed protein nanoparticles comprising genetically engineered elastin-like polypeptides (ELPs) with fused polyaspartic acid tails (ELP-D). Epidermal growth factor (EGF) was displayed on the surface of the ELP-D nanoparticles via genetic design to allow for active cell-targeting abilities. Herein, we focused on the coiled-coil structural motif as a means for noncovalent tethering of growth factor to ELP-D. Specifically, two peptides known to form a heterodimer via a coiled-coil structural motif were fused to ELP-D and single-chain vascular endothelial growth factor (scVEGF121), to facilitate noncovalent tethering upon formation of the heterodimer coiled-coil structure. Drug-loaded growth factor-tethered ELP-Ds were found to be effective against cancer cells by provoking cell apoptosis. These results demonstrate that tethering growth factor to protein nanoparticles through coiled-coil formation yields a promising biomaterial candidate for targeted drug delivery.

  10. 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.

  11. Deformation of Linked Polymer Coils

    Institute of Scientific and Technical Information of China (English)

    董朝霞; 李明远; 吴肇亮; 林梅钦

    2003-01-01

    Linked polymer solution (LPS) is defined as the solution of linked polymer coils (LPCs) dispersed in water, composed of low concentration partially hydrolyzed polyacrylamide (HPAM) and aluminum citrate (crosslinker). In the work, the conformational changes of LPCs under different conditions were investigated by the methods of membrane filtering under low pressure, dynamic light scattering and core flooding experiments. The results showed that in some conditions the LPCs could be compressed mechanically to 1/158.5 of their original volume because of relatively lower HPAM cross-linking. The hydration property of LPCs was similar to that of normal polymer coils. The deformation of LPCs was more restricted than that of ordinary polymer coils under the flow shear stress or the shift of hydration equilibrium caused in the variation of the electrolyte concentration which is responsible for the effective plugging in the throats of porous media when LPCs are used for deep diverting.

  12. Coil Optimization for HTS Machines

    DEFF Research Database (Denmark)

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

    for different tape parameters Ici, ni and Ci, where Ici, ni and Ci are critical current, n - value and price of the ith tape respectively and i=1, 2, 3…, further optimization with respect to cost vs. HTS losses has been performed. Allowing for different types of HTS tapes in the coils, a guidance to which tape....... The proposed coil design is optimized with respect to minimizing the perpendicular field while still maximizing the amplitude of fundamental space harmonic. This guarantees the lowest HTS loss density and best utilization of expensive HTS material in the field winding of the SM. Additionally, accounting...

  13. Electromagnetic Gun With Commutated Coils

    Science.gov (United States)

    Elliott, David G.

    1991-01-01

    Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

  14. [Two Cases of Ruptured Cerebral Aneurysm Complicated with Delayed Coil Protrusion after Coil Embolization].

    Science.gov (United States)

    Furukawa, Takashi; Ogata, Atsushi; Ebashi, Ryo; Takase, Yukinori; Masuoka, Jun; Kawashima, Masatou; Abe, Tatsuya

    2016-07-01

    We report two cases of delayed coil protrusion after coil embolization for ruptured cerebral aneurysms. Case 1:An 82-year-old woman with a subarachnoid hemorrhage due to a ruptured small anterior communicating artery aneurysm underwent successful coil embolization. Eighteen days after the procedure, coil protrusion from the aneurysm into the right anterior cerebral artery was observed without any symptoms. Further coil protrusion did not develop after 28 days. Case 2:A 78-year-old woman with a subarachnoid hemorrhage due to a ruptured small left middle cerebral artery aneurysm underwent successful coil embolization. Twenty days after the procedure, coil protrusion from the aneurysm into the left middle cerebral artery was observed, with a transient ischemic attack. Further coil protrusion did not develop. Both patients recovered with antithrombotic treatment. Even though delayed coil protrusion after coil embolization is rare, it should be recognized as a long-term complication of coil embolization for cerebral aneurysms.

  15. Coupled Coils, Magnets and Lenz's Law

    Science.gov (United States)

    Thompson, Frank

    2010-01-01

    Great scientists in the past have experimented with coils and magnets. Here we have a variation where coupling occurs between two coils and the oscillatory motion of two magnets to give somewhat surprising results. (Contains 6 figures and 1 footnote.)

  16. Generalization of Helmholtz coil problem

    Directory of Open Access Journals (Sweden)

    Petković Dejan M.

    2015-01-01

    Full Text Available The primary intent of this work is to propose a simple analytical method for designing coil systems for homogeneous and gradient magnetostatic field generation. Coil system consists of two identical coaxial (regular polygonal current loops. In the space between the loops, there is nearly homogeneous or nearly linear distribution of the magnetic field along the axes depending on the currents' direction. First, we derived a suitable, simple and general expression for the magnetic field along the axes due to a polygonal current loop. We emphasize the importance of the role of this expression for further analysis. The total on-axes magnetic field is the result of superposition of the magnetic fields that each loop generates separately. The proper distance between the loops and the current orientation make the system to become either Helmholtz coil or anti-Helmholtz coil. In this paper we give exact, analytical and general expression for this optimal distance that provides the magnetic field to be homogeneous (linear as much as possible. We based our study on Taylor series expansion of the total magnetic field, demanding that the first contaminating term must be canceled, in both, symmetric and asymmetric case.

  17. Rotor assembly including superconducting magnetic coil

    Energy Technology Data Exchange (ETDEWEB)

    Snitchler, Gregory L. (Shrewsbury, MA); Gamble, Bruce B. (Wellesley, MA); Voccio, John P. (Somerville, MA)

    2003-01-01

    Superconducting coils and methods of manufacture include a superconductor tape wound concentrically about and disposed along an axis of the coil to define an opening having a dimension which gradually decreases, in the direction along the axis, from a first end to a second end of the coil. Each turn of the superconductor tape has a broad surface maintained substantially parallel to the axis of the coil.

  18. 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

  19. 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...

  20. The many types of interhelical ionic interactions in coiled coils - an overview.

    Science.gov (United States)

    Meier, Markus; Stetefeld, Jörg; Burkhard, Peter

    2010-05-01

    Coiled coils represent the most frequent protein oligomerization motif in nature and are involved in many important biological processes. The prototype interhelical ionic interaction for coiled coils described in literature is an i to i+5 ionic interaction from heptad position g to e', but other possible ionic interactions have also been described. Here we use a statistical approach to systematically analyze all high-quality coiled-coil structures in the RCSB protein database for their interhelical ionic interactions. We provide a complete listing of all possible arrangements and analyze the frequency of their occurrence in the primary sequence together with their probability of formation in the quaternary structure of the coiled coils. We show that the classical i to i+5 ionic interaction is indeed characteristic for parallel dimeric and trimeric coiled coils. But we also show that there are many more i to i+2 ionic interactions in parallel tetrameric and pentameric coiled coils, and in antiparallel coiled coils the classical i to i+5 ionic interaction is in none of the oligomerizations states the most frequently observed ionic interaction. We also demonstrate that many ionic interactions involve residues at the core positions that are usually occupied by hydrophobic residues and that such interhelical ionic interactions are a hallmark feature of dimeric coiled coils.

  1. An online monitoring system for atmospheric nitrous acid (HONO) based on stripping coil and ion chromatography

    Institute of Scientific and Technical Information of China (English)

    Peng Cheng; Yafang Cheng; Keding Lu; Hang Su; Qiang Yang; Yikan Zou; Yanran Zhao

    2013-01-01

    A new instrument for measuring atmospheric nitrous acid (HONO) was developed,consisting of a double-wail glass stripping coil sampler coupled with ion chromatography (SC-IC).SC-IC is featured by small size (50 × 35 × 25 cm) and modular construction,including three independent parts:the sampling unit,the transfer and supporting unit,and the detection unit.High collection efficiency (> 99%) was achieved with 25 μmol/L Na2CO3 as absorption solution even in the presence of highly acidic compounds.This instrument has a detection limit of 8 pptv at 15 min time resolution,with a measurement uncertainty of 7%.Potentiai interferences from NOx,NO2+SO2,NO2+VOCs,HONO+O3,HNO3,peroxyacetyl nitrite (PAN) and particle nitrite were quantified in laboratory studies and were found to be insignificant under typical atmospheric conditions.Within the framework of the 3C-STAR project,inter-comparison between the SC-IC and LOPAP (long path liquid absorption photometer) was conducted at a rurai site in the Pearl River Delta.Good agreement was achieved between the two instruments over three weeks.Both instruments determined a clear diurnai profile of ambient HONO concentrations from 0.1 to 2.5 ppbv.However,deviations were found for low ambient HONO concentrations (i.e.<0.3 ppbv),which cannot be explained by previous investigated interference species.To accurately determine the HONO budget under illuminated conditions,more intercomparison of HONO measurement techniques is still needed in future studies,especiaily at low HONO concentrations.

  2. Design of a shielded coil element of a matrix gradient coil

    Science.gov (United States)

    Jia, Feng; Littin, Sebastian; Layton, Kelvin J.; Kroboth, Stefan; Yu, Huijun; Zaitsev, Maxim

    2017-08-01

    The increasing interest in spatial encoding with non-linear magnetic fields has intensified the need for coils that generates such fields. Matrix coils consisting of multiple coil elements appear to offer a high flexibility in generating customized encoding fields and are particularly promising for localized high resolution imaging applications. However, coil elements of existing matrix coils were primarily designed and constructed for better shimming and therefore are not expected to achieve an optimal performance for local spatial encoding. Moreover, eddy current properties of such coil elements were not fully explored. In this work, an optimization problem is formulated based on the requirement of local non-linear encoding and eddy current reduction that results in novel designs of coil elements for an actively-shielded matrix gradient coil. Two metrics are proposed to assess the performance of different coil element designs. The results are analyzed to reveal new insights into coil element design.

  3. 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.

  4. 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.

  5. Performance evaluation of matrix gradient coils.

    Science.gov (United States)

    Jia, Feng; Schultz, Gerrit; Testud, Frederik; Welz, Anna Masako; Weber, Hans; Littin, Sebastian; Yu, Huijun; Hennig, Jürgen; Zaitsev, Maxim

    2016-02-01

    In this paper, we present a new performance measure of a matrix coil (also known as multi-coil) from the perspective of efficient, local, non-linear encoding without explicitly considering target encoding fields. An optimization problem based on a joint optimization for the non-linear encoding fields is formulated. Based on the derived objective function, a figure of merit of a matrix coil is defined, which is a generalization of a previously known resistive figure of merit for traditional gradient coils. A cylindrical matrix coil design with a high number of elements is used to illustrate the proposed performance measure. The results are analyzed to reveal novel features of matrix coil designs, which allowed us to optimize coil parameters, such as number of coil elements. A comparison to a scaled, existing multi-coil is also provided to demonstrate the use of the proposed performance parameter. The assessment of a matrix gradient coil profits from using a single performance parameter that takes the local encoding performance of the coil into account in relation to the dissipated power.

  6. Quenching in coupled adiabatic coils

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.C.

    1985-03-01

    The prediction of the effects of a quench on stress and temperature is an important aspect of the design of superconducting magnets. Of particular interest, and the exclusive topic of this study, is the prediction of the effects of quenching in coupled adiabatic coils, such as the multi-section windings of a high field NMR spectrometer magnet. The predictive methods used here are based on the measurement of the time of propagation of quench between turns. From this measurement an approximate algorithum for the propagation time is used in a code which solves the linear differential equations for the coil currents and calculates the movement of normal zone boundaries and hence the associated winding resistance.

  7. Starch gelatinization in coiled heaters.

    Science.gov (United States)

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  8. Coiled transmission line pulse generators

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Kenneth Fox (Columbia, MO)

    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.

  9. Self-correction coil: operation mechanism of self-correction coil

    Energy Technology Data Exchange (ETDEWEB)

    Hosoyama, K.

    1983-06-01

    We discuss here the operation mechanism of self-correction coil with a simple model. At the first stage, for the ideal self-correction coil case we calculate the self-inductance L of self-correction coil, the mutual inductance M between the error field coil and the self-correction coil, and using the model the induced curent in the self-correction coil by the external magnetic error field and induced magnetic field by the self-correction coil. And at the second stage, we extend this calculation method to non-ideal self-correction coil case, there we realize that the wire distribution of self-correction coil is important to get the high enough self-correction effect. For measure of completeness of self-correction effect, we introduce the efficiency eta of self-correction coil by the ratio of induced magnetic field by the self-correction coil and error field. As for the examples, we calculate L, M and eta for two cases; one is a single block approximation of self-correction coil winding and the other is a two block approximation case. By choosing the adequate angles of self-correction coil winding, we can get about 98% efficiency for single block approximation case and 99.8% for two block approximation case. This means that by using the self-correction coil we can improve the field quality about two orders.

  10. Mosquito coil emissions and health implications.

    Science.gov (United States)

    Liu, Weili; Zhang, Junfeng; Hashim, Jamal H; Jalaludin, Juliana; Hashim, Zailina; Goldstein, Bernard D

    2003-09-01

    Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.

  11. Optimum coil insertion speed of various coils in brain aneurysm embolization in vitro.

    Science.gov (United States)

    Konishi, Yoshifumi; Takeuchi, Masataka; Fukasaku, Kazuaki

    2016-10-01

    A coil must comprise material with shape memory to perform optimal coil embolization. To achieve this, the alloy characteristics of the coil (hardness, shape, and thickness) must be understood. In this experiment, a catheter was fixed in the bright position and the movement of the coil was observed under a constant rate of insertion; the optimal insertion rate during clinical use was investigated. The first coil insertion speed was evaluated using simulated aneurysms in an in vivo arterial model. The results showed that the insertion force relates to the deployment shape of the coil, that the feedback through the force indicator using sound is very effective, and that the recorder is useful for analysis of coil embolization. The inserted coils during aneurysm embolization were able to wind uniformly within the aneurysm due to a variety of factors (guiding or micro-catheter position and kick-back phenomenon such as delivery wire). Optimal speed is achieved with proper coil design, which allows the coil to be inserted into the aneurysm. The shape and size of the aneurysm can help determine the necessary size and design of the coil that should be used during the optimal speed range. Aneurysm wall and coil characteristics are considered, along with the friction state of the coil (hardness, shape, and thickness), leading to improvements in safety during the insertion procedure at optimum speed.

  12. Unusually Stable Helical Coil Allotrope of Phosphorus.

    Science.gov (United States)

    Liu, Dan; Guan, Jie; Jiang, Jingwei; Tománek, David

    2016-12-14

    We have identified an unusually stable helical coil allotrope of phosphorus. Our ab initio density functional theory calculations indicate that the uncoiled, isolated straight one-dimensional chain is equally stable as a monolayer of black phosphorus dubbed phosphorene. The coiling tendency and the attraction between adjacent coil segments add an extra stabilization energy of ∼12 meV/atom to the coil allotrope, similar in value to the ∼16 meV/atom interlayer attraction in bulk black phosphorus. Thus, the helical coil structure is essentially as stable as black phosphorus, the most stable phosphorus allotrope known to date. With an optimum radius of 2.4 nm, the helical coil of phosphorus may fit well and even form inside wide carbon nanotubes.

  13. The Golgin Family of Coiled-Coil Tethering Proteins

    Directory of Open Access Journals (Sweden)

    Tomasz M Witkos

    2016-01-01

    Full Text Available The golgins are a family of predominantly coiled-coil proteins that are localized to the Golgi apparatus. Golgins are present in all eukaryotes, suggesting an evolutionary conserved function. Golgins are anchored to the Golgi membrane by their carboxy terminus and are predicted to adopt an extended conformation that projects into the surrounding cytoplasm. This arrangement is ideal for the capture or tethering of nearby membranes or cytoskeletal elements. Golgin-mediated tethering is thought to be important for vesicular traffic at the Golgi apparatus, the maintenance of Golgi architecture, as well as the positioning of the Golgi apparatus within cells. In addition to acting as tethers, some golgins can also sequester various factors at the Golgi membrane, allowing for the spatiotemporal regulation of downstream cellular functions. Although it is now established that golgins are membrane and cytoskeleton tethers, the mechanisms underlying tethering remain poorly defined. Moreover, the importance of golgin-mediated tethering in a physiological context remains to be fully explored. This review will describe our current understanding of golgin function, highlighting recent progress that has been made, and goes on to discuss outstanding questions and potential avenues for future research with regard to this family of conserved Golgi-associated proteins.

  14. Force modulated conductance of artificial coiled-coil protein monolayers.

    Science.gov (United States)

    Atanassov, Alexander; Hendler, Ziv; Berkovich, Inbal; Ashkenasy, Gonen; Ashkenasy, Nurit

    2013-01-01

    Studies of charge transport through proteins bridged between two electrodes have been the subject of intense research in recent years. However, the complex structure of proteins makes it difficult to elucidate transport mechanisms, and the use of simple peptide oligomers may be an over simplified model of the proteins. To bridge this structural gap, we present here studies of charge transport through artificial parallel coiled-coil proteins conducted in dry environment. Protein monolayers uniaxially oriented at an angle of ∼ 30° with respect to the surface normal were prepared. Current voltage measurements, obtained using conductive-probe atomic force microscopy, revealed the mechano-electronic behavior of the protein films. It was found that the low voltage conductance of the protein monolayer increases linearly with applied force, mainly due to increase in the tip contact area. Negligible compression of the films for loads below 26 nN allowed estimating a tunneling attenuation factor, β(0) , of 0.5-0.6 Å(-1) , which is akin to charge transfer by tunneling mechanism, despite the comparably large charge transport distance. These studies show that mechano-electronic behavior of proteins can shed light on their complex charge transport mechanisms, and on how these mechanisms depend on the detailed structure of the proteins. Such studies may provide insightful information on charge transfer in biological systems.

  15. An Experimental Study on Constraint Cooling Process of Hot-rolled CoilS

    Institute of Scientific and Technical Information of China (English)

    Lijuan WANG; Chunli ZHANG

    2003-01-01

    In order to master mechanical property, surface quality and microstructure of constraint cooling (CC) coils undervarious water cooling parameters, more than 100 coils cooling experiments were done with real production process,of which is designed a coolin

  16. 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.

  17. 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.

  18. 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.

  19. Overexpression of Transforming Acidic Coiled Coil‑Containing Protein 3 Reflects Malignant Characteristics and Poor Prognosis of Glioma

    Directory of Open Access Journals (Sweden)

    Ying Sun

    2017-03-01

    Full Text Available Gliomas are malignant primary brain tumors with poor prognosis. Recently, research was indicative of a tight connection between tumor malignancy and genetic alterations. Here, we propose an oncogenic implication of transforming acidic coiled-coil-containing protein 3 (TACC3 in gliomas. By comprehensively analyzing the Chinese glioma genome atlas (CGGA and publicly available data, we demonstrated that TACC3 were overexpressed along with glioma grade and served as an independent negative prognostic biomarker for glioma patients. Functions’ annotations and gene sets’ enrichment analysis suggested that TACC3 may participate in cell cycle, DNA repair, epithelium-mesenchymal transition and other tumor-related biological processes and molecular pathways. Patients with high TACC3 expression showed CD133+ stem cell properties, glioma plasticity and shorter overall survival time under chemo-/radio-therapy. Additionally, a TACC3 associated the miRNA-mRNA network was constructed based on in silico prediction and expression pattern, which provide a foundation for further detection of TACC3-miRNA-mRNA axis function. Collectively, our observations identify TACC3 as an oncogene of tumor malignancy, as well as a prognostic and motoring biomarker for glioma patients.

  20. Peptidyl Materials Formed Through Click Chemistry Enhanced Coiled-Coil Interactions

    Science.gov (United States)

    Koehler, Kenneth

    2014-03-01

    Biologically derived materials offer a level of sophistication synthetically fabricated materials have only attempted to mimic. This level of complexity may be found in materials such as peptides. Implementing new theory and modeling, peptides with the propensity to form coiled-coil (CC) bundles were designed and synthesized. Through the use of this de novo approach, modeling allowed prediction of the feasibility to include non-natural amino acids conducive to click chemistry into the peptide. Amino acids showcasing thiol or alkyne functionalities were considered owing to the ability of these moieties to participate in the thiol-ene and copper click reactions respectively. Once synthesized, the peptides decorated with these clickable motifs were placed in solution and allowed to self-assemble into CC's. CD spectroscopy and DLS experiments confirmed the formation and assembly of CC's. Click reactions were then incited to link the CC assemblies together and form a network with predictable dimensionality and pore size between CC bundles. To incite network formation, click reactions between CC side chain residues and suitably functionalized crosslinkers were implemented. The linking of coiled-coils and material formation were assessed using DLS and TEM.

  1. 49 CFR 236.730 - Coil, receiver.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Coil, receiver. 236.730 Section 236.730 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Coil, receiver. Concentric layers of insulated wire wound around the core of a receiver of an...

  2. Operator coil monitoring Acceptance Test Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Erhart, M.F.

    1995-05-16

    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.

  3. 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.

  4. 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. The optimiz...

  5. 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…

  6. NMR local coil with adjustable spacing

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, G.T.

    1988-03-22

    A local coil assembly for use in NMR imaging is described which comprises: a base; a first local coil module mounted to the base and extending upward therefrom; sockets disposed in the base, each at a different distance from the first local coil module; a second local coil module having a connector therein which mates with each of the sockets to enable the second local coil module to be connected to the base at any one of the sockets; and a set of reactive components. The values of the respective reactive components are selected such that the second local oil module may be connected to any of the sockets without any substantial change in the resonant frequency of the assembly.

  7. A study on geometry effect of transmission coil for micro size magnetic induction coil

    Science.gov (United States)

    Lee, Kyung Hwa; Jun, Byoung Ok; Kim, Seunguk; Lee, Gwang Jun; Ryu, Mingyu; Choi, Ji-Woong; Jang, Jae Eun

    2016-05-01

    The effects of transmission (Tx) coil structure have been studied for micro-size magnetic induction coil. The size of the receiving (Rx) coil should be shrunk to the micrometer level for the various new applications such as micro-robot and wireless body implanted devices. In case of the macro-scale magnetic induction coil, the power transmission efficiency is generally considered to be higher as the inductance of the transmission coil became larger; however, the large size difference between macro-size Tx coil and micro-size Rx coil can decrease the power transmission efficiency due to the difference of resonance frequency. Here, we study a correlation of the power transmission with the size and distance between the macro-size Tx and micro-size Rx coils using magnetic induction technique. The maximum power efficiency was 0.28/0.23/0.13/0.12% at the distance of 0.3/1/3/5 cm between Rx and Tx coil. In addition, more efficient wireless power transferring method is suggested with a floating coil for the body implantable devices. The voltage output increased up to 5.4 mV than the original one Tx coil system. The results demonstrated the foundational wireless power transferring system with enhanced power efficiency.

  8. Detection of alpha-helical coiled-coil dimer formation by spin-labeled synthetic peptides: a model parallel coiled-coil peptide and the antiparallel coiled coil formed by a replica of the ProP C-terminus.

    Science.gov (United States)

    Hillar, Alexander; Tripet, Brian; Zoetewey, David; Wood, Janet M; Hodges, Robert S; Boggs, Joan M

    2003-12-30

    Electron paramagnetic resonance spectroscopy was used to determine relative peptide orientation within homodimeric, alpha-helical coiled-coil structures. Introduction of cysteine (Cys) residues into peptides/proteins for spin labeling allows detection of their oligomerization from exchange broadening or dipolar interactions between residues within 25 A of each other. Two synthetic peptides containing Cys substitutions were used: a 35-residue model peptide and the 30-residue ProP peptide. The model peptide is known to form a stable, parallel homodimeric coiled coil, which is partially destabilized by Cys substitutions at heptad a and d positions (peptides C30a and C33d). The ProP peptide, a 30-residue synthetic peptide, corresponds to residues 468-497 of osmoregulatory transporter ProP from Escherichia coli. It forms a relatively unstable, homodimeric coiled coil that is predicted to be antiparallel in orientation. Cys was introduced in heptad g positions of the ProP peptide, near the N-terminus (K473C, creating peptide C473g) or closer to the center of the sequence (E480C, creating peptide C480g). In contrast to the destabilizing effect of Cys substitution at the core heptad a or d positions of model peptides C30a and C33d, circular dichroism spectroscopy showed that Cys substitutions at the heptad g positions of the ProP peptide had little or no effect on coiled-coil stability. Thermal denaturation analysis showed that spin labeling increased the stability of the coiled coil for all peptides. Strong exchange broadening was detected for both C30a and C33d, in agreement with a parallel structure. EPR spectra of C480g had a large hyperfine splitting of about 90 G, indicative of strong dipole-dipole interactions and a distance between spin-labeled residues of less than 9 A. Spin-spin interactions were much weaker for C473g. These results supported the hypothesis that the ProP peptide primarily formed an antiparallel coiled coil, since formation of a parallel dimer

  9. pH-dependent Response of Coiled Coils: A Coarse-Grained Molecular Simulation Study

    CERN Document Server

    Enciso, Marta; Site, Luigi Delle

    2013-01-01

    In a recent work we proposed a coarse-grained methodology for studying the response of peptides when simulated at different values of pH; in this work we extend the methodology to analyze the pH-dependent behavior of coiled coils. This protein structure presents a remarkable chain stiffness andis formed by two or more long helical peptides that are interacting like the strands of a rope. Chain length and rigidity are the key aspects needed to extend previous peptide interaction potentials to this particular case; however the original model is naturally recovered when the length or the ridigity of the simulated chain are reduced. We apply the model and discuss results for two cases: (a) the folding/unfolding transition of a generic coiled coil as a function of pH; (b) behavior of a specific sequence as a function of the acidity conditions. In this latter case results are compared with experimental data from the literature in order to comment about the consistency of our approach.

  10. 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.

  11. 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.

  12. Spaced-based search coil magnetometers

    Science.gov (United States)

    Hospodarsky, George B.

    2016-12-01

    Search coil magnetometers are one of the primary tools used to study the magnetic component of low-frequency electromagnetic waves in space. Their relatively small size, mass, and power consumption, coupled with a good frequency range and sensitivity, make them ideal for spaceflight applications. The basic design of a search coil magnetometer consists of many thousands of turns of wire wound on a high permeability core. When a time-varying magnetic field passes through the coil, a time-varying voltage is induced due to Faraday's law of magnetic induction. The output of the coil is usually attached to a preamplifier, which amplifies the induced voltage and conditions the signal for transmission to the main electronics (usually a low-frequency radio receiver). Search coil magnetometers are usually used in conjunction with electric field antenna to measure electromagnetic plasma waves in the frequency range of a few hertz to a few tens of kilohertzs. Search coil magnetometers are used to determine the properties of waves, such as comparing the relative electric and magnetic field amplitudes of the waves, or to investigate wave propagation parameters, such as Poynting flux and wave normal vectors. On a spinning spacecraft, they are also sometimes used to determine the background magnetic field. This paper presents some of the basic design criteria of search coil magnetometers and discusses design characteristics of sensors flown on a number of spacecraft.

  13. Switching transients in a superconducting coil

    Energy Technology Data Exchange (ETDEWEB)

    Owen, E.W.; Shimer, D.W.

    1983-11-18

    A study is made of the transients caused by the fast dump of large superconducting coils. Theoretical analysis, computer simulation, and actual measurements are used. Theoretical analysis can only be applied to the simplest of models. In the computer simulations two models are used, one in which the coil is divided into ten segments and another in which a single coil is employed. The circuit breaker that interrupts the current to the power supply, causing a fast dump, is represented by a time and current dependent conductance. Actual measurements are limited to measurements made incidental to performance tests on the MFTF Yin-yang coils. It is found that the breaker opening time is the critical factor in determining the size and shape of the transient. Instantaneous opening of the breaker causes a lightly damped transient with large amplitude voltages to ground. Increasing the opening time causes the transient to become a monopulse of decreasing amplitude. The voltages at the external terminals are determined by the parameters of the external circuit. For fast opening times the frequency depends on the dump resistor inductance, the circuit capacitance, and the amplitude on the coil current. For slower openings the dump resistor inductance and the current determine the amplitude of the voltage to ground at the terminals. Voltages to ground are less in the interior of the coil, where transients related to the parameters of the coil itself are observed.

  14. Crystal Structure of the Central Coiled-Coil Domain from Human Liprin-[beta]2

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, Ryan L.; Tang, Ming-Yun; Sawaya, Michael R.; Phillips, Martin L.; Bowie, James U. (UCLA)

    2012-02-07

    Liprins are a conserved family of scaffolding proteins important for the proper regulation and development of neuronal synapses. Humans have four liprin-{alpha}s and two liprin-{beta}s 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-{beta}2 coiled-coil forms an extended dimer. Several protease-resistant subdomains within the liprin-{beta}1 and liprin-{beta}2 coiled-coils were also identified. A 2.0 {angstrom} crystal structure of the central, protease-resistant core of the liprin-{beta}2 coiled-coil reveals a parallel helix orientation. These studies represent an initial step toward determining the overall architecture of liprin scaffolds and understanding the molecular basis for their synaptic functions.

  15. Coil migration after endovascular coil occlusion of internal carotid artery pseudoaneurysms within the sphenoid sinus.

    Science.gov (United States)

    Struffert, T; Buhk, J H; Buchfelder, M; Rohde, V; Doerfler, A; Knauth, M

    2009-04-01

    We report two cases of coil migration after endovascular treatment of pseudoaneurysm of the internal carotid artery within the sphenoid sinus with coils and noncovered stents. Two patients underwent sphenoid sinus exposure for pituitary adenoma and chronic infection, respectively. As a complication pseudoaneurysms of the internal carotid artery within the sphenoid sinus developed. One patient was treated with stent and coils, the second with coils alone. Both patients experienced coil migration after 9 and 26 months, respectively, with the necessity for further treatment. Imaging was performed using flat detector computed tomography (FD-CT). Literature review revealed two additional cases of coil migration and four patients with the same treatment in stable condition. Pseudoaneurysms of the internal carotid artery are a special entity and the environment of the aneurysm within the sphenoid sinus may change over a long time. Coil embolization may lead to the late onset complication of coil migration with the possible risk of acute epistaxis. As a consequence, these patients need a careful and prolonged follow up. FD-CT is an appropriate technique to visualize the implanted coils and if present the migration of coil material.

  16. Superconducting coil development and motor demonstration: Overview

    Science.gov (United States)

    Gubser, D. U.

    1995-12-01

    Superconducting bismuth-cuprate wires, coils, and magnets are being produced by industry as part of a program to test the viability of using such magnets in Naval systems. Tests of prototype magnets, coils, and wires reveal progress in commercially produced products. The larger magnets will be installed in an existing superconducting homopolar motor and operated initially at 4.2K to test the performance. It is anticipated that approximately 400 Hp will be achieved by the motor. This article reports on the initial tests of the magnets, coils, and wires as well as the development program to improve their performance.

  17. 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.

  18. D-Cysteine Ligands Control Metal Geometries within de Novo Designed Three-Stranded Coiled Coils.

    Science.gov (United States)

    Pecoraro, Vincent Louis; Ruckthong, Leela; Peacock, Anna F A; Pascoe, Cherilyn E; Hemmingsen, Lars; Stuckey, Jeanne A

    2017-04-06

    While metal ion binding to naturally occurring L-amino acid proteins is well documented, understanding the impact of the opposite chirality (D) amino acids on the structure and stereochemistry of metals is in its infancy. We examine the effect of a D-configuration cysteine within a designed L-amino acid three-stranded coiled coil in order to enforce a precise coordination number on a metal center. The D-chirality does not alter the native fold, but the side-chain reorientation modifies the sterics of the metal binding pocket. L-Cys side-chains within the coiled-coil have previously been shown to rotate substantially from their preferred positions in the apo structure to create a binding site for a tetra-coordinate metal ion. However, here we show by x-ray crystallography that D-Cys side chains are preorganized with suitable geometry to bind such a ligand. This is confirmed by comparison of the Zn(II)Cl(CSL16DC)₃²¯ to the published Zn(II)(H₂O)(GRAND-CSL12AL16LC)₃¯.¹ Spectroscopic analysis indicates that the Cd(II) geometry observed using L-Cys ligands (a mixture of 3- and 4- coordinate Cd(II)) is altered to a single 4-coordinate specie when D-Cys is present. This work opens a new avenue for the control of metal site environment in man-made proteins, by simply altering the binding ligand with its mirror imaged D-configuration. Thus, use of D amino acids in a metal's coordination sphere promises to be a powerful tool for controlling the properties of future metalloproteins.

  19. Helical coil thermal hydraulic model

    Science.gov (United States)

    Caramello, M.; Bertani, C.; De Salve, M.; Panella, B.

    2014-11-01

    A model has been developed in Matlab environment for the thermal hydraulic analysis of helical coil and shell steam generators. The model considers the internal flow inside one helix and its associated control volume of water on the external side, both characterized by their inlet thermodynamic conditions and the characteristic geometry data. The model evaluates the behaviour of the thermal-hydraulic parameters of the two fluids, such as temperature, pressure, heat transfer coefficients, flow quality, void fraction and heat flux. The evaluation of the heat transfer coefficients as well as the pressure drops has been performed by means of the most validated literature correlations. The model has been applied to one of the steam generators of the IRIS modular reactor and a comparison has been performed with the RELAP5/Mod.3.3 code applied to an inclined straight pipe that has the same length and the same elevation change between inlet and outlet of the real helix. The predictions of the developed model and RELAP5/Mod.3.3 code are in fairly good agreement before the dryout region, while the dryout front inside the helical pipes is predicted at a lower distance from inlet by the model.

  20. Coil measurement data acquisition and curing press control system for SSC dipole magnet coils

    Energy Technology Data Exchange (ETDEWEB)

    Dickey, C.E.

    1989-03-01

    A coil matching program, similar in theory to the methods used to match Tevatron coils, is being developed at Fermilab. Modulus of elasticity and absolute coil size will be determined at 18-inch intervals along the coils while in the coil curing press immediately following the curing process. A data acquisition system is under construction to automatically acquire and manage the large quantities of data that result. Data files will be transferred to Fermilab's VAX Cluster for long-term storage and actual coil matching. The data acquisition system will also provide the control algorithm for the curing press hydraulic system. A description of the SSC Curing Press Data Acquisition and Controls System will be reported. 20 figs.

  1. 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.

  2. Magnetic propulsion of a magnetic device using three square-Helmholtz coils and a square-Maxwell coil.

    Science.gov (United States)

    Ha, Yong H; Han, Byung H; Lee, Soo Y

    2010-02-01

    We introduce a square coil system for remote magnetic navigation of a magnetic device without any physical movements of the coils. We used three square-Helmholtz coils and a square-Maxwell coil for magnetic propulsion of a small magnet along the desired path. All the square coils are mountable on a cubic frame that has an opening to accommodate a living subject. The square-Helmholtz coils control the magnetic propulsion direction by generating uniform magnetic field along the desired direction while the square-Maxwell coil controls the propulsion force by generating magnetic gradient field. We performed magnetic propulsion experiments with a down-scaled coil set and a three-channel coil driver. Experimental results demonstrate that we can use the square coil set for magnetic navigation of a magnetic device without any physical movements of the coils.

  3. 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.

  4. A Calibrating Device for Rogowski Coil Development

    Institute of Scientific and Technical Information of China (English)

    LV Liang; LI Junhao; HUANG Jianjun; JI Shengchang; LI Yanming

    2007-01-01

    A calibrating device for the Rogowski coil is developed,which can be used to calibrate the Rogowski coil having a partial response time within tens of nanoseconds.Its key component is a step current generator,which can generate the output with a rise time of less than 2 ns and a duration of larger than 300 ns.The step current generator is composed by a pulse forming line(PFL)and a pulse transmission line(PTL).A TEM(transverse electromagnetic mode)coaxial measurement unit is used as PTL,and the coil to be calibrated and the referenced standard Rogowski coil can be fixed in the unit.The effect of the dimensions of the TEM unit is discussed theoretically as well as experimentally.

  5. Screen-printed flexible MRI receive coils.

    Science.gov (United States)

    Corea, Joseph R; Flynn, Anita M; Lechêne, Balthazar; Scott, Greig; Reed, Galen D; Shin, Peter J; Lustig, Michael; Arias, Ana C

    2016-03-10

    Magnetic resonance imaging is an inherently signal-to-noise-starved technique that limits the spatial resolution, diagnostic image quality and results in typically long acquisition times that are prone to motion artefacts. This limitation is exacerbated when receive coils have poor fit due to lack of flexibility or need for padding for patient comfort. Here, we report a new approach that uses printing for fabricating receive coils. Our approach enables highly flexible, extremely lightweight conforming devices. We show that these devices exhibit similar to higher signal-to-noise ratio than conventional ones, in clinical scenarios when coils could be displaced more than 18 mm away from the body. In addition, we provide detailed material properties and components performance analysis. Prototype arrays are incorporated within infant blankets for in vivo studies. This work presents the first fully functional, printed coils for 1.5- and 3-T clinical scanners.

  6. Coiling Temperature Control in Hot Strip Mill

    Science.gov (United States)

    Imanari, Hiroyuki; Fujiyama, Hiroaki

    Coiling temperature is one of the most significant factors in products of hot strip mill to determine material properties such as strength, toughness of steel, so it is very important to achieve accurate coiling temperature control (CTC). Usually there are a few pyrometers on the run out table in hot strip mill, therefore temperature model and its adapting system have large influences on the accuracy of CTC. Also unscheduled change of rolling speed has a bad effect to keep coiling temperature as its target. Newly developed CTC system is able to get very accurate coiling temperature against uncertain factors and disturbances by adopting easily identified temperature model, learning method and dynamic set up function. The features of the CTC system are discussed with actual data, and the effectiveness of the system is shown by actual control results.

  7. 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

  8. Mechanical resonances of helically coiled carbon nanowires

    National Research Council Canada - National Science Library

    Saini, D; Behlow, H; Podila, R; Dickel, D; Pillai, B; Skove, M J; Serkiz, S M; Rao, A M

    2014-01-01

    ...) mainly due to their geometrical complexity. The advent of helically coiled micro/nanoscale structures in nano-robotics, nano-inductors, and impact protection coatings has necessitated the development of new methodologies for determining...

  9. The Magnetic Field of Helmholtz Coils

    Science.gov (United States)

    Berridge, H. J. J.

    1975-01-01

    Describes the magnetic field of Helmholtz coils qualitatively and then provides the basis for a quantitative expression. Since the mathematical calculations are very involved, a computer program for solving the mathematical expression is presented and explained. (GS)

  10. Constraint Cooling of Hot Rolled Coil

    Institute of Scientific and Technical Information of China (English)

    WANG Li-juan; ZHANG Chun-li

    2004-01-01

    The layer thermal conductivity during constraint cooling of hot rolled coil was described by using equivalent thermal conductivity model and finite element method. Two radial stress concentration zones in constraint cooled coil were shown by numerical analysis, and the tension stress was assumed to be the main factor to induce stress corrosion. The experimental results show that the longer the water cooling time is, the smaller the grain size and the more uniform the grains are.

  11. NUMERICAL INVESTIGATION FOR THE HEAT TRANSFER ENHANCEMENT IN HELICAL CONE COILS OVER ORDINARY HELICAL COILS

    Directory of Open Access Journals (Sweden)

    M. M. ABO ELAZM

    2013-02-01

    Full Text Available This numerical research is introducing the concept of helical cone coils and their enhanced heat transfer characteristics compared to the ordinary helical coils. Helical and spiral coils are known to have better heat and mass transfer than straight tubes, which is attributed to the generation of a vortex at the helical coil known as Dean Vortex. The Dean number which is a dimensionless number used to describe the Dean vortex is a function of Reynolds number and the square root of the curvature ratio, so varying the curvature ratio for the same coil would vary the Dean number. Two scenarios were adopted to study the effect of changing the taper angle (curvature ratio on the heat transfer characteristics of the coil; the commercial software FLUENT was used in the investigation. It was found that Nusselt number increased with increasing the taper angle. A MATLAB code was built based on empirical correlation of Manlapaz and Churchill for ordinary helical coils to calculate the Nusselt number at each coil turn, and then calculate the average Nusselt number for the entire coil turns, the CFD simulation results were found acceptable when compared with the MATLAB results.

  12. AC loss measurements in HTS coil assemblies with hybrid coil structures

    Science.gov (United States)

    Jiang, Zhenan; Long, Nicholas J.; Staines, Mike; Badcock, Rodney A.; Bumby, Chris W.; Buckley, Robert G.; Amemiya, Naoyuki

    2016-09-01

    Both AC loss and wire cost in coil windings are critical factors for high temperature superconductor (HTS) AC machinery applications. We present AC loss measurement results in three HTS coil assemblies at 77 K and 65 K which have a hybrid coil structure comprising one central winding (CW) and two end windings (EWs) wound with ReBCO and BSCCO wires with different self-field I c values at 77 K. All AC loss results in the coil assemblies are hysteretic and the normalized AC losses in the coil assemblies at different temperatures can be scaled with the I c value of the coil assemblies. The normalised results show that AC loss in a coil assembly with BSCCO CW can be reduced by using EWs wound with high I c ReBCO wires, whilst further AC loss reduction can be achieved by replacing the BSCCO CW with ReBCO CW. The results imply that a flexible hybrid coil structure is possible which considers both AC loss and wire cost in coil assemblies.

  13. A Condition for a Translation Quiver to Be a Coil

    Institute of Scientific and Technical Information of China (English)

    Bin ZHU; Zong Yi HU

    2003-01-01

    We single out a class of translation quivers and prove combinatorially that the translationquivers in this class are coils. These coils form a class of special coils. They are easier to visualize, butstill show all the strange behaviour of general coils, and contain quasi-stable tubes as special examples.

  14. Embroidered Coils for Magnetic Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Michael I. Newton

    2013-04-01

    Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.

  15. Solid catalytic growth mechanism of micro-coiled carbon fibers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Micro-coiled carbon fibers were prepared by catalytic pyrolysisof acetylene with nano-sized nickel powder catalyst using the substrate method. The morphology of micro-coiled carbon fibers was observed through field emission scanning electron microscopy. It was found that the fiber and coil diameter of the obtained micro-coiled carbon fibers is about 500—600 nm and 4—5 μm, respectively. Most of the micro-coiled carbon fibers obtained were regular double carbon coils, but a few irregular ones were also observed. On the basis of the experimental observation, a solid catalytic growth mechanism of micro-coiled carbon fibers was proposed.

  16. Minimum Inductance Optimal Design for the Gradient Coil

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In MRI (Magnetic Resonance Imaging), a crucial role of gradient coils is to image organism, meanwhile the inductance of the coils determines the speed of imaging. So it is of great importance to optimize designs of the gradient coils. The target field approach is an effective method to design the gradient coils. Having applied this method and performing many numerical tests, we achieved the designs of the x-、y-、z- gradient coils , with the linearity of the fields generated by the coils in a sphere of radius 0.30 m less than 5%, in which the inductance and resistance of the coils also meet the requirements.

  17. Surgical management of an ACM aneurysm eight years after coiling.

    Science.gov (United States)

    Pogády, P; Fellner, F; Trenkler, J; Wurm, G

    2007-04-01

    The authors present a case report on rebleeding of a medial cerebral aneurysm (MCA) eight years after complete endovascular coiling. The primarily successfully coiled MCA aneurysm showed a local regrowth which, however, was not the source of the rebleeding. The angiogram demonstrated no evidence of contrast filling of the coiled segment, but according to intraoperative findings (haematoma location, displacement of coils, evident place of rupture) there is no doubt that the coiled segment of the aneurysm was responsible for the haemorrhage.

  18. Quench Protection of DI-BSCCO Coil

    Science.gov (United States)

    Yamaguchi, T.; Ueno, E.; Kato, T.; Hayashi, K.

    Quench protection is one of the most important requirements for the practical application of high-temperature-superconducting (HTS) coils. Quench protection requires that early detection of a developing quench event is followed by rapid reduction of the operating current. However, such quench detection is very difficult because HTS wire produces heat only locally due to the very slow propagation velocity of a normal zone. Excellent high voltage insulation performance is required if the current is to be reduced rapidly in a large-scale superconducting application with very large inductance. Thus it is important to investigate the behavior of coils with various decay time constants, and to detect voltages on very short time scales. This goal remains to be achieved. In the present study we built test coil and a full-scale pole coil for a 20 MW motor for use in experiments on quench protection, and parameterized the relation between the decay time constant and the detecting voltage, using a conventional balance circuit to detect the quench, which was generated by gradually raising the temperature of the coils. The results verify that a balance circuit can be used for quench detection. For example, when the current decay time constant is 4 seconds, the test coil can be protected even with a detecting voltage of 0.15 volts, despite a significant heat production rate of 126 W. We also confirmed that the full-scale pole coil, with a decay time constant of 20 seconds, can be protected with a detecting voltage of 0.06 V.

  19. In vitro and in vivo delivery of functionalized nanoparticles via coiled-coil interactions

    NARCIS (Netherlands)

    Yang, J.

    2016-01-01

    This thesis presents another approach for direct cytosolic delivery via membrane fusion. This approach is based on a complementary pair of coiled-coil forming peptides, K (KIAALKE)4 and E (EIAALEK)4 and is mimicking the action of the SNARE-complex. The SNARE-complex is responsible for fusion between

  20. An iterative method for coil sensitivity estimation in multi-coil MRI systems.

    Science.gov (United States)

    Ling, Qiang; Li, Zhaohui; Song, Kaikai; Li, Feng

    2014-12-01

    This paper presents an iterative coil sensitivity estimation method for multi-coil MRI systems. The proposed method works with coil images in the magnitude image domain. It determines a region of support (RoS), a region being composed of the same type of tissues, by a region growing algorithm, which makes use of both intensities and intensity gradients of pixels. By repeating this procedure, it can determine multiple regions of support, which together cover most of the concerned image area. The union of these regions of support provides a rough estimate of the sensitivity of each coil through dividing the intensities of pixels by the average intensity inside every region of support. The obtained rough coil sensitivity estimate is further approached with the product of multiple low-order polynomials, rather than a single one. The product of these polynomials provides a smooth estimate of the sensitivity of each coil. With the obtained sensitivities of coils, it can produce a better reconstructed image, which determines more correct regions of support and yields preciser estimates of the sensitivities of coils. In other words, the method can be iteratively implemented to improve the estimation performance. The proposed method was verified through both simulated data and clinical data from different body parts. The experimental results confirm the superiority of our method to some conventional methods.

  1. A coiled-coil domain acts as a molecular ruler in LPS chain length regulation

    Science.gov (United States)

    Tuukkanen, Anne; Danciu, Iulia; Svergun, Dmitri I.; Hussain, Rohanah; Liu, Huanting; Whitfield, Chris; Naismith, James H.

    2014-01-01

    Long-chain bacterial polysaccharides play important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter dependent polysaccharide assembly, a large extracellular carbohydrate with a narrow distribution of size is polymerized from monosaccharides by a complex of two proteins, WbdA (polymerase) and WbdD (terminating protein). Such careful control of polymerization is recurring theme in biology. Combining crystallography and small angle X-ray scattering, we show that the C-terminal domain of WbdD contains an extended coiled-coil that physically separates WbdA from the catalytic domain of WbdD. The effects of insertions and deletions within the coiled-coil region were analyzed in vivo, revealing that polymer size is controlled by varying the length of the coiled-coil domain. Thus, the coiled-coil domain of WbdD functions as a molecular ruler that, along with WbdA:WbdD stoichiometry, controls the chain length of a model bacterial polysaccharide. PMID:25504321

  2. Minimax current density gradient coils: analysis of coil performance and heating.

    Science.gov (United States)

    Poole, Michael S; While, Peter T; Lopez, Hector Sanchez; Crozier, Stuart

    2012-08-01

    Standard gradient coils are designed by minimizing the inductance or resistance for an acceptable level of gradient field nonlinearity. Recently, a new method was proposed to minimize the maximum value of the current density in a coil additionally. The stated aim of that method was to increase the minimum wire spacing and to reduce the peak temperature in a coil for fixed efficiency. These claims are tested in this study with experimental measurements of magnetic field and temperature as well as simulations of the performance of many coils. Experimental results show a 90% increase in minimum wire spacing and 40% reduction in peak temperature for equal coil efficiency and field linearity. Simulations of many more coils indicate increase in minimum wire spacing of between 50 and 340% for the coils studied here. This method is shown to be able to increase coil efficiency when constrained by minimum wire spacing rather than switching times or total power dissipation. This increase in efficiency could be used to increase gradient strength, duty cycle, or buildability.

  3. 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

  4. 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 golgin

  5. 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 cor

  6. A high-resolution structure that provides insight into coiled-coil thiodepsipeptide dynamic chemistry.

    Science.gov (United States)

    Dadon, Zehavit; Samiappan, Manickasundaram; Shahar, Anat; Zarivach, Raz; Ashkenasy, Gonen

    2013-09-16

    Stable and reactive: A crystal structure at 1.35 Å of a thioester coiled-coil protein reveals high similarity to all-peptide-bond proteins. In these assemblies, the thioester bonds are kept reactive towards thiol molecules in the mixture. This enables efficient domain exchange between proteins in response to changes in folding conditions or introduction of external templates.

  7. Allosteric effects in coiled-coil proteins folding and lanthanide-ion binding.

    Science.gov (United States)

    Samiappan, Manickasundaram; Alasibi, Samaa; Cohen-Luria, Rivka; Shanzer, Abraham; Ashkenasy, Gonen

    2012-10-07

    Peptide sequences modified with lanthanide-chelating groups at their N-termini, or at their lysine side chains, were synthesized, and new Ln(III) complexes were characterized. We show that partial folding of the conjugates to form trimer coiled coil structures induces coordination of lanthanides to the ligand, which in turn further stabilizes the 3D structure.

  8. Analysis and experimental study of wireless power transfer with HTS coil and copper coil as the intermediate resonators system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiufang [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Physics and Technology, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Nie, Xinyi [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Liang, Yilang [School of Physics and Technology, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Lu, Falong [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Yan, Zhongming, E-mail: wangxiufanghappy@163.com [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Wang, Yu [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2017-01-15

    Highlights: • We investigated a kind of system architecture with three coils which the repeater is copper coil or HTS coil. • We simulated the different repeater system and obtained the magnetic field distribution at different distance. • We used helical coil instead of pancake coil which does not use capacitors. • HTS intermediate coil has significant effect on improving the transmission efficiency and lengthening transmission distance than copper intermediate coil. - Abstract: Intermediate resonator (repeater) between transmitter and receiver can significantly increase the distance of wireless power transfer (WPT) and the efficiency of wireless power transfer. The wireless power transfer via strongly coupled magnetic resonances with an high temperature superconducting (HTS) coil and copper coil as intermediate resonators was presented in this paper. The electromagnetic experiment system under different conditions with different repeating coils were simulated by finite element software. The spatial distribution patterns of magnetic induction intensity at different distances were plotted. In this paper, we examined transfer characteristics with HTS repeating coil and copper repeating coil at 77 K and 300 K, respectively. Simulation and experimental results show that HTS and copper repeating coil can effectively enhance the space magnetic induction intensity, which has significant effect on improving the transmission efficiency and lengthening transmission distance. We found that the efficiency and the distance of wireless power transfer system with an HTS coil as repeater is much higher by using of copper coil as repeater.

  9. 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

  10. Critical current studies of a HTS rectangular coil

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Z. [Department of Engineering, University of Cambridge (United Kingdom); Chudy, M., E-mail: Michal.chudy@stuba.sk [Graduate School of Technology Management, University of Pretoria (South Africa); Institute of Power and Applied Electrical Engineering, Slovak University of Technology in Bratislava (Slovakia); Ruiz, H.S. [Department of Engineering, University of Leicester, Leicester LE1 7RH (United Kingdom); Zhang, X.; Coombs, T. [Department of Engineering, University of Cambridge (United Kingdom)

    2017-05-15

    Highlights: • Unique square pancake coil was manufactured. • Measurements in relatively high magnetic field were performed. • Different sections of the coil were characterized. • Parts of the coil which are limiting critical current were identified. - Abstract: Nowadays, superconducting high field magnets are used in numerous applications due to their superior properties. High temperature superconductors (HTS) are usually used for production of circular pancake or racetrack coils. However different geometries of HTS coils might be required for some specific applications. In this study, the HTS coil wound on a rectangular frame was fully characterized in homogeneous DC background field. The study contains measurements of critical current angular dependencies. The critical current of the entire coil and two selected strands under different magnitudes and orientations of external magnetic fields are measured. The critical regions of the coil in different angular regimes are determined. This study brings better understanding of the in- field performance of HTS coils wound on frames with right-angles.

  11. Fabrication of the planar coils for WENDELSTEIN 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Viebke, H. [Max-Planck-Institut fuer Plasmaphysik, Greifswald Branch, Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany)]. E-mail: holger.viebke@ipp.mpg.de; Rummel, Th. [Max-Planck-Institut fuer Plasmaphysik, Greifswald Branch, Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Risse, K. [Max-Planck-Institut fuer Plasmaphysik, Greifswald Branch, Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Schroeder, R. [Max-Planck-Institut fuer Plasmaphysik, Greifswald Branch, Euratom Association, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Winter, R. [Tesla Engineering Ltd., Water Lane, Storrington, Sussex RH20 3EA (United Kingdom)

    2005-11-15

    WENDELSTEIN 7-X (W7-X) is a superconducting stellarator, which uses 50 non-planar coils for the main field and 20 planar coils to modify the magnetic configuration. The planar coils are cut into two differently shaped types and designed for 3 T on the plasma axis. A planar coil has an outer diameter of around 4 m. The main elements of planar coils are the winding package, the coil case, the interlayer joints to connect the double layers, and the case cooling with instrumentation. The connection to the coil support structure is performed through forged blocks welded to the casing and bolts. The manufacturing is being performed with a high accuracy to maintain the required symmetry of the magnetic configuration of W7-X. Prior to dispatch the coils pass a works acceptance test at Tesla. After production, all coils are subjected to a functional test at cryogenic temperatures at the Low Temperature Laboratory of CEA at Saclay.

  12. Wireless power transmission applied the mutual coupling between coils

    Science.gov (United States)

    Furuta, Kenta; Baba, Ryouichi; Shun, Endo; Nunokawa, Kazuki; Takahashi, Wataru; Maruyama, Tamami

    2017-07-01

    Recently, the studies of wireless power transfer (WPT) to electric vehicles in motion on the snow-piled road have been reported. In WPT by magnetic field resonance method, transmission coefficient S21, which is one of the scattering parameters, from transmission coil to received coil are degraded because of misalignment of transmitting and receiving coil, the distance between these coils, and the effects of the ice and snow. This paper adopts parasitic coil as a solution to improve the reception power in which the parasitic coil is inserted between transmitting and receiving coils. Analysis and experimental results show that parasitic coil could improve the value of S21 by 15 dB using mutual coupling. LED could be light by this solution when the distance between transmitting and receiving coils are 150 mm.

  13. Surface Coil for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Beatriz Taimy Ricardo Ferro

    2015-01-01

    Full Text Available Currently Magnetic Resonance Imaging (MRI, has become a vital tool for the clinical diagnosis of various diseases, especially in the Nervisos Central System and the Musculos keletal System. Coils(RF are an essential component in the generation of these images, are responsible for exciting thespins of nuclei in a sample and/or detect the resultant signal coming from them. The use of surface RF coils has increased considerably, because they have a high signal to noise ratio, a parameter that defines the quality of the image. In the present work, there was realized the theoretical design and practical implementation of a circular surface RF coil. The experimental prototype was optimized to be used in the tomograph Giroimag03  built in Medical Biophysics Center

  14. 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.  

  15. 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)

  16. 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.

  17. Measuring the orthogonality error of coil systems

    Science.gov (United States)

    Heilig, B.; Csontos, A.; Pajunpää, K.; White, Tim; St. Louis, B.; Calp, D.

    2012-01-01

    Recently, a simple method was proposed for the determination of pitch angle between two coil axes by means of a total field magnetometer. The method is applicable when the homogeneous volume in the centre of the coil system is large enough to accommodate the total field sensor. Orthogonality of calibration coil systems used for calibrating vector magnetometers can be attained by this procedure. In addition, the method can be easily automated and applied to the calibration of delta inclination–delta declination (dIdD) magnetometers. The method was tested by several independent research groups, having a variety of test equipment, and located at differing geomagnetic observatories, including: Nurmijärvi, Finland; Hermanus, South Africa; Ottawa, Canada; Tihany, Hungary. This paper summarizes the test results, and discusses the advantages and limitations of the method.

  18. MFTF test coil construction and performance

    Energy Technology Data Exchange (ETDEWEB)

    Cornish, D.N.; Zbasnik, J.P.; Leber, R.L.; Hirzel, D.G.; Johnston, J.E.; Rosdahl, A.R.

    1978-09-25

    A solenoid coil, 105 cm inside the 167 cm outside diameter, has been constructed and tested to study the performance of the stabilized Nb--Ti conductor to be used in the Mirror Fusion Test Facility (MFTF) being built at Lawrence Livermore Laboratory. The insulation system of the test coil is identical to that envisioned for MFTF. Cold-weld joints were made in the conductor at the start and finish of each layer; heaters were fitted to some of these joints and also to the conductor at various locations in the winding. This paper gives details of the construction of the coil and the results of the tests carried out to determine its propagation and recovery characteristics.

  19. The d'--d--d' vertical triad is less discriminating than the a'--a--a' vertical triad in the antiparallel coiled-coil dimer motif.

    Science.gov (United States)

    Steinkruger, Jay D; Bartlett, Gail J; Hadley, Erik B; Fay, Lindsay; Woolfson, Derek N; Gellman, Samuel H

    2012-02-08

    Elucidating relationships between the amino-acid sequences of proteins and their three-dimensional structures, and uncovering non-covalent interactions that underlie polypeptide folding, are major goals in protein science. One approach toward these goals is to study interactions between selected residues, or among constellations of residues, in small folding motifs. The α-helical coiled coil has served as a platform for such studies because this folding unit is relatively simple in terms of both sequence and structure. Amino acid side chains at the helix-helix interface of a coiled coil participate in so-called "knobs-into-holes" (KIH) packing whereby a side chain (the knob) on one helix inserts into a space (the hole) generated by four side chains on a partner helix. The vast majority of sequence-stability studies on coiled-coil dimers have focused on lateral interactions within these KIH arrangements, for example, between an a position on one helix and an a' position of the partner in a parallel coiled-coil dimer, or between a--d' pairs in an antiparallel dimer. More recently, it has been shown that vertical triads (specifically, a'--a--a' triads) in antiparallel dimers exert a significant impact on pairing preferences. This observation provides impetus for analysis of other complex networks of side-chain interactions at the helix-helix interface. Here, we describe a combination of experimental and bioinformatics studies that show that d'--d--d' triads have much less impact on pairing preference than do a'--a--a' triads in a small, designed antiparallel coiled-coil dimer. However, the influence of the d'--d--d' triad depends on the lateral a'--d interaction. Taken together, these results strengthen the emerging understanding that simple pairwise interactions are not sufficient to describe side-chain interactions and overall stability in antiparallel coiled-coil dimers; higher-order interactions must be considered as well.

  20. Resistive demountable toroidal-field coils for tokamak reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jassby, D.L.; Jacobsen, R.A.; Kalnavarns, J.; Masson, L.S.; Sekot, J.P.

    1981-07-01

    Readily demountable TF (toroidal-field) coils allow complete access to the internal components of a tokamak reactor for maintenance of replacement. The requirement of readily demountable joints dictates the use of water-cooled resistive coils, which have a host of decisive advantages over superconducting coils. Previous papers have shown that resistive TF coils for tokamak reactors can operate in the steady state with acceptable power dissipation (typically, 175 to 300 MW). This paper summarizes results of parametric studies of size optimization of rectangular TF coils and of a finite-element stress analysis, and examines several candidate methods of implementing demountable joints for rectangular coils constructed of plate segments.

  1. Analytical and experimental analysis of tube coil heat exchanger

    Science.gov (United States)

    Smusz, R.

    2016-09-01

    The paper presents the analytical and experimental analysis of heat transfer for the finned tube coil heat exchanger immersed in thermal storage tank. The tank is equipped with three helical-shaped heating coils and cylindrical- shaped stratification device. Two coils, upper and lower, use the water as a heating medium. The third, double wall heat exchanger coil, located at the bottom head on the tank is filled by the refrigerant (freon). Calculations of thermal power of water coil were made. Correlations of heat transfer coefficients in curved tubes were applied. In order to verify the analytical calculations the experimental studies of heat transfer characteristic for coil heat exchanger were performed.

  2. Final design and construction of the Wendelstein7-X coils

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, L. E-mail: lutz.wegener@ipp.mpg.de; Feist, J.-H.; Sapper, J.; Kerl, F.; Werner, F

    2001-11-01

    The Stellarator of the Wendelstein 7-X (W7-X) experiment contains a system of 50 non-planar and 20 planar superconducting coils. The coils were designed by the IPP. The coil manufacturing and inspection is shared between several European enterprises and consortiums. The coils consist of the winding pack embedded in a stainless steel casing and of the related instrumentation. Design details, tolerances and guarantee values and differences between the coils types are described in the contribution. The features of the superconductor are described separately. Finally, the contribution indicates measures adopted by the W7-X project to ensure the quality of the coil design and manufacturing.

  3. Self-assembling segmented coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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.

  5. A HTS dipole insert coil constructed

    CERN Document Server

    Ballarino, A; Rey, J M; Stenvall, A; Sorbi, M; Tixador, P

    2013-01-01

    This report is the deliverable report 7.4.1 “A HTS dipole insert coil constructed“. The report has three parts: “Design report for the HTS dipole insert”, “One insert pancake prototype coil constructed with the setup for a high field test”, and “All insert components ordered”. The three report parts show that, although the insert construction will be only completed by end 2013, all elements are present for a successful completion and that, given the important investments done by the participants, there is a full commitment of all of them to finish the project

  6. Estimation and measurement of flat or solenoidal coil inductance for radiofrequency NMR coil design.

    Science.gov (United States)

    Rainey, Jan K; DeVries, Jeffrey S; Sykes, Brian D

    2007-07-01

    The inductance of a radiofrequency coil determines its compatibility with a given NMR probe circuit. However, calculation (or estimation) of inductance for radiofrequency coils of dimensions suitable for use in an NMR probe is not trivial, particularly for flat-coils. A comparison of a number of formulae for calculation of inductance is presented through the use of a straightforward inductance measurement circuit. This technique relies upon instrumentation available in many NMR laboratories rather than upon more expensive and specialized instrumentation often utilized in the literature. Inductance estimation methods are suggested and validated for both flat-coils and solenoids. These have proven very useful for fabrication of a number of new coils in our laboratory for use in static solid-state NMR probes operating at (1)H frequencies of 300 and 600MHz. Solenoidal coils with very similar measured and estimated inductances having inner diameters from 1 to 5mm are directly compared as an example of the practical application of inductance estimation for interchange of coils within an existing solid-state NMR probe.

  7. Research and development of MRI surface coil for TMJ MR imaging; Modulated Helmholtz surface coil

    Energy Technology Data Exchange (ETDEWEB)

    Kukimoto, Yoshiaki; Kukimoto, Kyoko (Kameda General Hospital, Kamogawa, Chiba (Japan)); Shirakawa, Toyomi

    1989-12-01

    Internal derangements of the temporomandibular joint (TMJ) are a major cause of jaw pain and dysfunction as well as other related clinical symptoms. TMJ diagnosis is the abnormal position and appearance of the disk. Most X-ray-based methods are useful for evaluating bony abnormalities, but their reduced soft-tissue contrast often makes the diagnostic evaluation of TMJ disorders difficult. Magnetic resonance (MR) imaging is a very recent addition to the medical diagnostic of TMJ diseases. MR imaging can produce high-quality tomographic images of greater soft-tissue contrast without ionizing radiation or known biological hazards. MR system was circular type Simens Magnetom 1.5 tesla. Display matrix was 256x256. A Modulated Helmholtz type coil of 17 cm in diameter was developed in Kameda General Hospital in order to increase signal to noise ratio in the area of bilateral TMJs. The distance between two coils was 16-20 cm. The head was placed in supine position in the center of two surface coils. A Modulated Helmholtz type coil: 1. Modulated Helmholtz type coil was used as an emitter and a receiver. 2. Modulated Helmholtz type coil had a pair of 17 cm coils, which were movable according to head width of each patient. 3. MR imaging of bilateral TMJs was taken at once because of no necessity to reset a surfacecoil. 4. It was easy to set positioning of the head. (author).

  8. Tx/Rx Head Coil Induces Less RF Transmit-Related Heating than Body Coil in Conductive Metallic Objects Outside the Active Area of the Head Coil.

    Science.gov (United States)

    Nagy, Zoltan; Oliver-Taylor, Aaron; Kuehne, Andre; Goluch, Sigrun; Weiskopf, Nikolaus

    2017-01-01

    The transmit-receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T clinical scanner and made temperature measurements around a straight 15 cm conductor using either the Tx/Rx body or the head coil for excitation. Additionally, the transmitted fields of a Tx/Rx head coil were measured both in air and in gel using a resonant and a non-resonant B field probes as well as a non-resonant E field probe. Simulations using a finite-difference time domain solver were compared with the experimental findings. When the body coil was used for excitation, we observed heating around the 15 cm wire at various anatomical locations (both within and outside of the active volume of the head coil). Outside its active area, no such heating was observed while using the Tx/Rx head coil for excitation. The E and B fields of the Tx/Rx birdcage head coil extended well-beyond the physical dimensions of the coil. In air, the fields were monotonically decreasing, while in gel they were more complex with local maxima at the end of the ASTM phantom. These experimental findings were line with the simulations. While caution must always be exercised when scanning individuals with metallic implants, these findings support the use of the Tx/Rx birdcage head coil in place of the body coil at 3T in order to reduce the risk of heating in and around conductive implants that are remote from the head coil.

  9. Tx/Rx Head Coil Induces Less RF Transmit-Related Heating than Body Coil in Conductive Metallic Objects Outside the Active Area of the Head Coil

    Science.gov (United States)

    Nagy, Zoltan; Oliver-Taylor, Aaron; Kuehne, Andre; Goluch, Sigrun; Weiskopf, Nikolaus

    2017-01-01

    The transmit–receive (Tx/Rx) birdcage head coil is often used for excitation instead of the body coil because of the presumably lower risk of heating in and around conductive implants. However, this common practice has not been systematically tested. To investigate whether the Tx/Rx birdcage head coil produces less heating than the body coil when scanning individuals with implants, we used a 3T clinical scanner and made temperature measurements around a straight 15 cm conductor using either the Tx/Rx body or the head coil for excitation. Additionally, the transmitted fields of a Tx/Rx head coil were measured both in air and in gel using a resonant and a non-resonant B field probes as well as a non-resonant E field probe. Simulations using a finite-difference time domain solver were compared with the experimental findings. When the body coil was used for excitation, we observed heating around the 15 cm wire at various anatomical locations (both within and outside of the active volume of the head coil). Outside its active area, no such heating was observed while using the Tx/Rx head coil for excitation. The E and B fields of the Tx/Rx birdcage head coil extended well-beyond the physical dimensions of the coil. In air, the fields were monotonically decreasing, while in gel they were more complex with local maxima at the end of the ASTM phantom. These experimental findings were line with the simulations. While caution must always be exercised when scanning individuals with metallic implants, these findings support the use of the Tx/Rx birdcage head coil in place of the body coil at 3T in order to reduce the risk of heating in and around conductive implants that are remote from the head coil.

  10. Optimization of a conduction-cooled LTS pulse coil

    Energy Technology Data Exchange (ETDEWEB)

    Kawagoe, A. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan)]. E-mail: kawagoe@eee.kagoshima-u.ac.jp; Yamamuro, H. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Sumiyoshi, F. [Kagoshima University, Kohrimoto 1-21-40, Kagoshima-shi, Kagoshima 890-0065 (Japan); Mito, T. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Chikaraishi, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Hemmi, T. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Baba, T. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Yokota, M. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Morita, Y. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Ogawa, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Abe, R. [Shibuya Kogyo Co., Ltd., Kanazawa, Ishikawa 920-0054 (Japan); Okumura, K. [Technova Inc., Chiyoda-ku, Tokyo 100-0011 (Japan); Iwakuma, M. [Kyushu University, Higashi-ku, Fukuoka 812-8581 (Japan)

    2006-11-15

    The output limit of the available power of a prototype conduction-cooled low temperature superconducting (LTS) pulse coil is clarified for the optimization of the coil. The winding conductor of this coil is a NbTi/Cu Rutherford cable, which is extruded with aluminum. Dyneema[reg] fiber reinforced plastics (DFRP) and Litz wires are used as the spacers of this coil. A prototype coil with a stored energy of 100 kJ was successfully fabricated and tested, and the coil performed excellently. In this paper, the stability margin of this coil is clarified by thermal analysis, using a two-dimensional finite element method, taking into account the effects of both types of spacers, DFRP and Litz wires. Additionally, the maximum output power of the coil is estimated at about three times the rated output.

  11. Modular Coils and Plasma Configurations for Quasi-axisymmetric Stellarators

    Energy Technology Data Exchange (ETDEWEB)

    L.P. Ku and A.H. Boozer

    2010-09-10

    Characteristics of modular coils for quasi-axisymmetric stellarators that are related to the plasma aspect ratio, number of field periods and rotational transform have been examined systematically. It is observed that, for a given plasma aspect ratio, the coil complexity tends to increase with the increased number of field periods. For a given number of field periods, the toroidal excursion of coil winding is reduced as the plasma aspect ratio is increased. It is also clear that the larger the coil-plasma separation is, the more complex the coils become. It is further demonstrated that it is possible to use other types of coils to complement modular coils to improve both the physics and the modular coil characteristics.

  12. Constrained length minimum inductance gradient coil design.

    Science.gov (United States)

    Chronik, B A; Rutt, B K

    1998-02-01

    A gradient coil design algorithm capable of controlling the position of the homogeneous region of interest (ROI) with respect to the current-carrying wires is required for many advanced imaging and spectroscopy applications. A modified minimum inductance target field method that allows the placement of a set of constraints on the final current density is presented. This constrained current minimum inductance method is derived in the context of previous target field methods. Complete details are shown and all equations required for implementation of the algorithm are given. The method has been implemented on computer and applied to the design of both a 1:1 aspect ratio (length:diameter) central ROI and a 2:1 aspect ratio edge ROI gradient coil. The 1:1 design demonstrates that a general analytic method can be used to easily obtain very short gradient coil designs for use with specialized magnet systems. The edge gradient design demonstrates that designs that allow imaging of the neck region with a head sized gradient coil can be obtained, as well as other applications requiring edge-of-cylinder regions of uniformity.

  13. Thermophoresis of polymers: nondraining vs draining coil.

    Science.gov (United States)

    Morozov, Konstantin I; Köhler, Werner

    2014-06-10

    Present theories for the thermophoretic mobility of polymers in dilute solution without long-ranged electrostatic interaction are based on a draining coil model with short-ranged segment-solvent interaction. We show that the characteristic thermophoretic interaction decays as r(-2) with the distance from the chain segment, which is of much longer range than the underlying rapidly decaying binary van der Waals interaction (∝ r(-6)). As a consequence, thermophoresis on the monomer level is governed by volume forces, resulting in hydrodynamic coupling between the chain segments. The inner parts of the nondraining coil do not actively participate in thermophoresis. The flow lines penetrate only into a thin surface layer of the coil and cause tangential stresses along the surface of the entire coil, not the individual segments. This model is motivated by recent experimental findings for thermoresponsive polymers and core-shell particles, and it explains the well-known molar mass independent thermophoretic mobility of polymers in dilute solution.

  14. Coil in bottom part of splitter magnet

    CERN Multimedia

    1976-01-01

    Radiation-resistant coil being bedded into the bottom part of a splitter magnet. This very particular magnet split the beam into 3 branches, for 3 target stations in the West-Area. See Annual Report 1975, p.176, Figs.14 and 15.

  15. Stellarator Coil Design and Plasma Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Long-Poe Ku and Allen H. Boozer

    2010-11-03

    The rich information contained in the plasma response to external magnetic perturbations can be used to help design stellarator coils more effectively. We demonstrate the feasibility by first devel- oping a simple, direct method to study perturbations in stellarators that do not break stellarator symmetry and periodicity. The method applies a small perturbation to the plasma boundary and evaluates the resulting perturbed free-boundary equilibrium to build up a sensitivity matrix for the important physics attributes of the underlying configuration. Using this sensitivity information, design methods for better stellarator coils are then developed. The procedure and a proof-of-principle application are given that (1) determine the spatial distributions of external normal magnetic field at the location of the unperturbed plasma boundary to which the plasma properties are most sen- sitive, (2) determine the distributions of external normal magnetic field that can be produced most efficiently by distant coils, (3) choose the ratios of the magnitudes of the the efficiently produced magnetic distributions so the sensitive plasma properties can be controlled. Using these methods, sets of modular coils are found for the National Compact Stellarator Experiment (NCSX) that are either smoother or can be located much farther from the plasma boundary than those of the present design.

  16. Penile hair coil strangulation of the child

    African Journals Online (AJOL)

    shanker

    We report the case of a child with a delayed presentation of penile strangulation with a coil of hair that resulted in a complete ... erection in some of them and with autoerotic intentions in others. ... in children with underlying urological problems.

  17. High-resolution MR imaging of triangular fibrocartilage complex (TFCC): comparison of microscopy coils and a conventional small surface coil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroshi [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, 02115, Boston, MA (United States); Ueno, Teruko; Itai, Yuji [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Tanaka, Toshikazu [Department of Orthopedic Surgery, Tsukuba Kinen Hospital, Tsukuba (Japan); Shindo, Masashi [Tsukuba University Hospital, Tsukuba (Japan)

    2003-10-01

    To compare MR images of the triangular fibrocartilage complex (TFCC) using microscopy coils with those using a conventional surface coil qualitatively and quantitatively. Proton density-weighted images and T2*-weighted images of the TFCC from ten normal volunteers were obtained with a conventional surface coil (C4 coil; 80 mm in diameter), a 47-mm microscopy surface coil and a 23-mm microscopy surface coil at 1.5 T. Qualitative image analysis of MR images with three coils was performed by two radiologists who assigned one of five numerical scores (0, nonvisualization; 1, poor; 2, average; 3, good; 4, excellent) for five TFCC components, which were disc proper, triangular ligament, meniscus homologue, ulnotriquetral and ulnolunate ligament. Quantitative analysis included the signal-to-noise ratio (S/N) of the disc proper of TFCC, the lunate cartilage, the lunate bone and the contrast-noise-ratio (C/N) between articular cartilage and disc proper or bone marrow were measured. All structures show higher scores qualitatively on MR with microscopy coils than those with a C4 coil, and the difference was significant with the exception of the ulnolunate ligament. MR with microscopy coils showed significantly higher S/N values than those with a conventional surface coil (P<0.05 to P<0.001). T2*-weighted images using microscopy coils showed significantly higher cartilage-disc proper C/N and cartilage-bone marrow C/N (P<0.01 to P<0.001). On proton density-weighted images, the C/N between cartilage and disc proper with two microscopy coils was significantly higher (P<0.01) than that with a conventional coil. High-resolution MR images of the normal wrist using microscopy coils were superior to those using a conventional surface coil qualitatively and quantitatively. High-resolution MR imaging with a microscopy coil would be a promising method to diagnose TFCC lesions. (orig.)

  18. Comparison of an Electromagnetic Energy Harvester Performance using Wound Coil Wire and PCB Coil

    Science.gov (United States)

    Resali, MSM; Salleh, H.

    2016-03-01

    This paper presents the performance of two types of electromagnetic energy harvester, one using manually wound coil wire (EH-EC) and the other one using printed circuit board (PCB) coil (EH-EP). The objective of the study is to measure the corresponding output voltage and power by varying the number of coils and the position of the magnet. The experiment was conducted at a fix 50 Hz of frequency and at 0.25g of acceleration. The EH-EP was found to be more effective than the 350 turns of the wound coil wire, with maximum power of 26 μW. Overall, the performance of the EH-EC showed better result with maximum power of 125 μW for 1050 turns when compared to the EH-EP.

  19. 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.

  20. Multiple-Coil, Pulse-Induction Metal Detector

    Science.gov (United States)

    Lesky, Edward S.; Reid, Alan M.; Bushong, Wilton E.; Dickey, Duane P.

    1988-01-01

    Multiple-head, pulse-induction metal detector scans area of 72 feet squared with combination of eight detector heads, each 3 ft. square. Head includes large primary coil inducing current in smaller secondary coils. Array of eight heads enables searcher to cover large area quickly. Pulses applied to primary coil, induced in secondary coils measured to determine whether metal present within range of detector head. Detector designed for recovery of Space Shuttle debris.

  1. Design and Testing of Coils for Pulsed Electromagnetic Forming

    OpenAIRE

    Golovashchenko, S.; Bessonov, N.; Davies, R

    2006-01-01

    Coil design influences the distribution of electromagnetic forces applied to both the blank and the coil. The required energy of the process is usually defined by deformation of the blank. However, the discharge also results in a significant amount of heat being generated and accumulating in the coil. Therefore, EMF process design involves working with three different problems: 1) propagation of an electromagnetic field through the coil-blank system and generation of pulsed electromagnetic pr...

  2. 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.

  3. Improved coiled-coil design enhances interaction with Bcr-Abl and induces apoptosis.

    Science.gov (United States)

    Dixon, Andrew S; Miller, Geoffrey D; Bruno, Benjamin J; Constance, Jonathan E; Woessner, David W; Fidler, Trevor P; Robertson, James C; Cheatham, Thomas E; Lim, Carol S

    2012-01-01

    The oncoprotein Bcr-Abl drives aberrant downstream activity through trans-autophosphorylation of homo-oligomers in chronic myelogenous leukemia (CML).(1, 2) The formation of Bcr-Abl oligomers is achieved through the coiled-coil domain at the N-terminus of Bcr.(3, 4) We have previously reported a modified version of this coiled-coil domain, CCmut2, which exhibits disruption of Bcr-Abl oligomeric complexes and results in decreased proliferation of CML cells and induction of apoptosis.(5) A major contributing factor to these enhanced capabilities is the destabilization of the CCmut2 homodimers, increasing the availability to interact with and inhibit Bcr-Abl. Here, we included an additional mutation (K39E) that could in turn further destabilize the mutant homodimer. Incorporation of this modification into CCmut2 (C38A, S41R, L45D, E48R, Q60E) generated what we termed CCmut3, and resulted in further improvements in the binding properties with the wild-type coiled-coil domain representative of Bcr-Abl [corrected]. A separate construct containing one revert mutation, CCmut4, did not demonstrate improved oligomeric properties and indicated the importance of the L45D mutation. CCmut3 demonstrated improved oligomerization via a two-hybrid assay as well as through colocalization studies, in addition to showing similar biologic activity as CCmut2. The improved binding between CCmut3 and the Bcr-Abl coiled-coil may be used to redirect Bcr-Abl to alternative subcellular locations with interesting therapeutic implications.

  4. 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.

  5. 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.

  6. Data-driven prediction and design of bZIP coiled-coil interactions.

    Science.gov (United States)

    Potapov, Vladimir; Kaplan, Jenifer B; Keating, Amy E

    2015-02-01

    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.

  7. 49 CFR 236.555 - Repaired or rewound receiver coil.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Repaired or rewound receiver coil. 236.555 Section 236.555 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... or rewound receiver coil. Receiver coil which has been repaired or rewound shall have the...

  8. 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

    Objective: To determine if presence of the Roach muscle, a small muscle bundle tying just beside the umbilical artery, contributes to umbilical cord coiling. Methods: 251 umbilical cords were examined. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length

  9. 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.

  10. The training in epoxy-impregnated superconducting coils

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H.; Bobrov, E.S.; Iwasa, Y.; Takaghi, T.; Tsukamoto, O.

    1985-03-01

    The authors have investigated the training of epoxy-impregnated superconducting coils. It has been observed that the boundary conditions at the coil ends have a crucial effect on shear-stress-induced epoxy cracks in the winding and consequently on the coil training. The results were quantified using acoustic emission data.

  11. Unconventional gradient coil designs in magnetic resonance imaging.

    Science.gov (United States)

    Zhu, Minhua; Xia, Ling; Liu, Feng

    2014-01-01

    In magnetic resonance imaging (MRI), the gradient coils are used to encode the spatial positions of protons by varying the magnetic field linearly across the imaging subject. With the latest development of MRI technique and new clinical and research applications, the gradient coil system requires increasingly innovative designs. In this paper, four unconventional gradient coil designs are reviewed: (1) local gradient coils; (2) new coil configurations with reduced peripheral nerve stimulation (PNS); (3) dedicated structures designed for hybrid systems (combining MRI with other medical devices); and (4) the full 3D coil designs. For the first type, the development of local gradient coils (mainly head coils) is discussed chronologically and divided into three stages: the "golden" stage in the 1990s, the "wane" stage in the 2000s, and the "revival" stage in the 2010s. For the second type, various designs for the reduction of PNS problems have been described, including local and whole-body gradient coil systems. For the third design, a dedicated gradient coil design for multi-modality combination is illustrated with an MRI-LINAC system. Finally, gradient systems with non-layered coil structure are described in the fourth design type. We hope that this review on unconventional gradient coil designs will be useful for the new development of MRI technology and emerging medical applications.

  12. Needleless Electrospinning of Uniform Nanofibers Using Spiral Coil Spinnerets

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2012-01-01

    Full Text Available Polyvinyl alcohol nanofibers were prepared by a needleless electrospinning technique using a rotating spiral wire coil as spinneret. The influences of coil dimension (e.g., coil length, coil diameter, spiral distance, and wire diameter and operating parameters (e.g., applied voltage and spinning distance on electrospinning process, nanofiber diameter, and fiber productivity were examined. It was found that the coil dimension had a considerable influence on the nanofiber production rate, but minor effect on the fiber diameter. The fiber production rate increased with the increased coil length or coil diameter, or the reduced spiral distance or wire diameter. Higher applied voltage or shorter collecting distance also improved the fiber production rate but had little influence on the fiber diameter. Compared with the conventional needle electrospinning, the coil electrospinning produced finer fibers with a narrower diameter distribution. A finite element method was used to analyze the electric field on the coil surface and in electrospinning zone. It was revealed that the high electric field intensity was concentrated on the coil surface, and the intensity was highly dependent on the coil dimension, which can be used to explain the electrospinning performances of coils. In addition, PAN nanofibers were prepared using the same needleless electrospinning technique to verify the improvement in productivity.

  13. Modeling Endovascular MRI Coil Coupling with Transmit RF Excitation

    Science.gov (United States)

    Venkateswaran, Madhav; Unal, Orhan; Hurley, Samuel; Samsonov, Alexey; Wang, Peng; Fain, Sean; Kurpad, Krishna

    2016-01-01

    Objective To model inductive coupling of endovascular coils with transmit RF excitation for selecting coils for MRI-guided interventions. Methods Independent and computationally efficient FEM models are developed for the endovascular coil, cable, transmit excitation and imaging domain. Electromagnetic and circuit solvers are coupled to simulate net B1+ fields and induced currents and voltages. Our models are validated using the Bloch Siegert B1+ mapping sequence for a series-tuned multimode coil, capable of tracking, wireless visualization and high resolution endovascular imaging. Results Validation shows good agreement at 24, 28 and 34 μT background RF excitation within experimental limitations. Quantitative coil performance metrics agree with simulation. A parametric study demonstrates trade off in coil performance metrics when varying number of coil turns. Tracking, imaging and wireless marker multimode coil features and their integration is demonstrated in a pig study. Conclusion Developed models for the multimode coil were successfully validated. Modeling for geometric optimization and coil selection serves as a precursor to time-consuming and expensive experiments. Specific applications demonstrated include parametric optimization, coil selection for a cardiac intervention and an animal imaging experiment. Significance Our modular, adaptable and computationally efficient modeling approach enables rapid comparison, selection and optimization of inductively-coupled coils for MRI-guided interventions. PMID:26960218

  14. A coiled-coil domain acts as a molecular ruler to regulate O-antigen chain length in lipopolysaccharide.

    Science.gov (United States)

    Hagelueken, Gregor; Clarke, Bradley R; Huang, Hexian; Tuukkanen, Anne; Danciu, Iulia; Svergun, Dmitri I; Hussain, Rohanah; Liu, Huanting; Whitfield, Chris; Naismith, James H

    2015-01-01

    Long-chain bacterial polysaccharides have important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter-dependent polysaccharide assembly, a large extracellular carbohydrate with a narrow size distribution is polymerized from monosaccharides by a complex of two proteins, WbdA (polymerase) and WbdD (terminating protein). Combining crystallography and small-angle X-ray scattering, we found that the C-terminal domain of WbdD contains an extended coiled-coil that physically separates WbdA from the catalytic domain of WbdD. The effects of insertions and deletions in the coiled-coil region were analyzed in vivo, revealing that polymer size is controlled by varying the length of the coiled-coil domain. Thus, the coiled-coil domain of WbdD functions as a molecular ruler that, along with WbdA:WbdD stoichiometry, controls the chain length of a model bacterial polysaccharide.

  15. Tailored Presentation of Carbohydrates on a Coiled Coil-Based Scaffold for Asialoglycoprotein Receptor Targeting.

    Science.gov (United States)

    Zacco, Elsa; Hütter, Julia; Heier, Jason L; Mortier, Jérémie; Seeberger, Peter H; Lepenies, Bernd; Koksch, Beate

    2015-09-18

    The coiled-coil folding motif represents an ideal scaffold for the defined presentation of ligands due to the possibility of positioning them at specific distances along the axis. We created a coiled-coil glycopeptide library to characterize the distances between the carbohydrate-binding sites of the asialoglycoprotein receptors (ASGPR) on hepatocytes. The components of the glycopeptide library vary for the number of displayed ligands (galactose), their position on the peptide sequence, and the space between peptide backbone and carbohydrate. We determined the binding of the glycopeptides to the hepatocytes, and we established the optimal distance and orientation of the galactose moieties for interaction with the ASGPR using flow cytometry. We confirmed that the binding occurs through endocytosis mediated by ASGPR via inhibition studies with cytochalasin D; fluorescence microscopy studies display the uptake of the carrier peptides inside the cell. Thus, this study demonstrates that the coiled-coil motif can be used as reliable scaffold for the rational presentation of ligands.

  16. CENP-K and CENP-H may form coiled-coils in the kinetochores

    Institute of Scientific and Technical Information of China (English)

    QIU ShuLan; WANG JiaNing; YU Chuang; HE DaCheng

    2009-01-01

    Kinetochores are large proteinaceous structure on the surface of chromosomes' primary constriction during mitosis. They link chromosomes to spindle microtubules and also regulate the spindle assem-bly checkpoint, which is crucial for correct chromosome segregation in all eukaryotes. The better known core networks of kinetochores include the KMN network (K, KNL1; M, Mis12 complex; N, Ndc80 complex)and CCAN (constitutive centromere-associated network). However, the detailed molecular mechanism of the kinetochore protein network remains unclear. This study demonstrates that CENP-H and CENP-K form quite stable subcomplex by TAP (tandem affinity purification) with HEK 293 cells which express TAP-CENP-K, with the ratio of purified CENP-H and CENP-K being close to 1 : 1 even with high salt. Bioinformatic analysis suggests that CENP-H and CENP-K are enriched with coiled-coil regions. This implies that CENP-H and CENP-K form heterodimeric coiled-coils. Furthermore, the func-tional regions which form the complex are respectively located on their N- and C-terminals, but the association between the C-terminals is more complex. It is possible that this is the first identified het-erodimeric coiled-coils within the inner kinetochore, which is directly involved in the attachment be-tween kinetochores and the spindle microtubules.

  17. 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

  18. CENP-K and CENP-H may form coiled-coils in the kinetochores

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Kinetochores are large proteinaceous structure on the surface of chromosomes’ primary constriction during mitosis. They link chromosomes to spindle microtubules and also regulate the spindle assem- bly checkpoint, which is crucial for correct chromosome segregation in all eukaryotes. The better known core networks of kinetochores include the KMN network (K, KNL1; M, Mis12 complex; N, Ndc80 complex)and CCAN (constitutive centromere-associated network). However, the detailed molecular mechanism of the kinetochore protein network remains unclear. This study demonstrates that CENP-H and CENP-K form quite stable subcomplex by TAP (tandem affinity purification) with HEK 293 cells which express TAP-CENP-K, with the ratio of purified CENP-H and CENP-K being close to 1︰1 even with high salt. Bioinformatic analysis suggests that CENP-H and CENP-K are enriched with coiled-coil regions. This implies that CENP-H and CENP-K form heterodimeric coiled-coils. Furthermore, the func- tional regions which form the complex are respectively located on their N- and C-terminals, but the association between the C-terminals is more complex. It is possible that this is the first identified het- erodimeric coiled-coils within the inner kinetochore, which is directly involved in the attachment be- tween kinetochores and the spindle microtubules.

  19. Solutions for Safe Hot Coil Evacuation and Coil Handling in Case of Thick and High Strength Steel

    OpenAIRE

    Sieberer Stefan; Pichler Lukas; Hackl Manfred

    2016-01-01

    Currently hot rolling plants are entering the market segment for thick gauges and high strength steel grades where the elastic bending property of the strip leads to internal forces in the coil during coiling operation. The strip tends to open. Primetals is investigating several possibilities to facilitate safe coil evacuation and coil handling under spring-back conditions. The contribution includes finite element models of such mechanical solutions. Results of parameter variation and stabili...

  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

    2016-07-21

    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. Study on the performance improvement of the high temperature superconducting coil with several separated coils at the edges

    Science.gov (United States)

    Ishiguri, S.; Oka, T.; Fukui, S.; Ogawa, J.; Sato, T.

    2008-09-01

    In designing high temperature superconducting (HTS) coils, it is important to secure large magnetic fields and stored energy using shorter tape length. Thus, it is necessary to improve the transport current performance of the coils. The critical current and n-value of an HTS tape depend on magnetic fields and flux angles under constant temperature. Considering these dependencies, we established a model to analyze coil critical current. This model clarifies that relatively large electric fields are generated at the coil edges. This adversely affects the transport current performance. In this study, the coil edge is separated into several coils, keeping the total tape length constant. This increases the coil critical current, stored energy, central magnetic field, and also the coil volume, which contains vacancies created by the separation. To estimate coil performance, we calculated the stored energy density, whose denominator is the increased coil volume. This stored energy density reaches its maximum value when the number of the separated coils is eight. At this optimum separation, the central magnetic field increases by 13%, and the stored energy improves by 43%, compared to a rectangular coil wound with the same tape length.

  2. Structural attributes for the recognition of weak and anomalous regions in coiled-coils of myosins and other motor proteins

    Directory of Open Access Journals (Sweden)

    Sunitha Margaret S

    2012-09-01

    Full Text Available Abstract 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.

  3. 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

    2008-06-01

    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.

  4. 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....

  5. Application of Microstructure Engineering in Steel Coil Cooling Process

    Institute of Scientific and Technical Information of China (English)

    LIU Zheng-dong; D Q Jin; I V Samarasekera; J K Brimacombe

    2005-01-01

    The coil cooling and its role in a hot strip mill were reviewed.A mathematical model was developed to describe and analyze the thermal history and its impact on precipitation phenomena during coil cooling for plain car bon,HSLA-V and HSLA-Nb steels.The predicted result of the thermal model was compared with that measured from industrial coil.The effect of cooling condition and coil dimension on the thermal history and final mechanical properties of the steel strip was examined.The coiling temperature and cooling rate have crucial influence on the precipitation strengthening.

  6. Superconducting coil system and methods of assembling the same

    Science.gov (United States)

    Rajput-Ghoshal, Renuka; Rochford, James H.; Ghoshal, Probir K.

    2016-01-19

    A superconducting magnet apparatus is provided. The superconducting magnet apparatus includes a power source configured to generate a current; a first switch coupled in parallel to the power source; a second switch coupled in series to the power source; a coil coupled in parallel to the first switch and the second switch; and a passive quench protection device coupled to the coil and configured to by-pass the current around the coil and to decouple the coil from the power source when the coil experiences a quench.

  7. Mechanical characteristics of the ATLAS B0 model coil

    CERN Document Server

    Foussat, A; Dudarev, A; Mayri, C; Miele, P; Sun, Z; ten Kate, H H J; Volpini, G

    2003-01-01

    The ATLAS B0 model coil has been tested at CERN to verify the design parameters of the Barrel Toroid coils (BT). The mechanical behavior of the B0 superconducting coil and its support structure is reported and compared with coil design calculations. The mechanical stresses and structural force levels during cooling down and excitation phases were monitored using strain gauges, position sensors and capacitive force transducers instrumentation. In the ATLAS magnet test facility, a magnetic mirror is used to reproduce the electromagnetic forces present in the BT coils, once these are assembled in toroid in the underground cavern in 2004. (8 refs).

  8. 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.

  9. Random coil chemical shift for intrinsically disordered proteins

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Brander, Søren; Poulsen, Flemming Martin

    2011-01-01

    . 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......, which allows the accurate random coil chemical shifts to be obtained at any pH. By correcting the random coil chemical shifts for the effects of temperature and pH, systematic biases of the secondary chemical shifts are minimized, which will improve the reliability of detection of transient secondary...

  10. 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.

  11. Fabrication of the superconducting coils for Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Risse, Konrad E-mail: konrad.risse@ipp.mpg.de; Rummel, Th.; Wegener, L.; Holzthuem, R.; Jaksic, N.; Kerl, F.; Sapper, J

    2003-09-01

    The Max Planck Institute of Plasma Physics is building up the stellarator fusion experiment Wendelstein 7-X (W7-X) at the branch institute in Greifswald. W7-X continues the line of stellarator experiments at IPP. To allow for steady state operation W7-X has a superconducting coil system with 50 non-planar and 20 planar coils. The coil system is grouped in five equal modules, each consisting of two mirror symmetric half modules. The half modules are assembled from five different non-planar coils, two planar coils and a sector of the coil support structure. All cryogenic parts are enclosed in a cryostat to protect them from ambient temperature. The magnet system was ordered from the European industry. The production of superconductor, winding packs and encasings are under way. The main focus of this contribution aims on the fabrication state of the coil system.

  12. Output beam analysis of high power COIL

    Institute of Scientific and Technical Information of China (English)

    Deli Yu(于德利); Fengting Sang(桑凤亭); Yuqi Jin(金玉奇); Yizhu Sun(孙以珠)

    2003-01-01

    As the output power of a chemical oxygen iodine laser (COIL) increases, the output laser beam instabilityappears as the far-field beam spot drift and deformation for the large Fresnel number unstable resonator.In order to interpret this phenomenon, an output beam mode simulation code was developed with the fastFourier transform method. The calculation results show that the presence of the nonuniform gain in COILproduces a skewed output intensity distribution, which causes the mirror tilt and bulge due to the thermalexpansion. With the output power of COIL increases, the mirror surfaces, especially the back surface ofthe scraper mirror, absorb more and more heat, which causes the drift and deformation of far field beamspot seriously. The initial misalignment direction is an important factor for the far field beam spot driftingand deformation.

  13. Theory of the quadrature elliptic birdcage coil.

    Science.gov (United States)

    Leifer, M C

    1997-11-01

    This paper presents the theory of the quadrature birdcage coil wound on an elliptic cylindrical former. A conformal transformation of the ellipse to a circular geometry is used to derive the optimal sampling of the continuous surface current distribution to produce uniform magnetic fields within an elliptic cylinder. The analysis is rigorous for ellipses of any aspect ratio and shows how to produce quadrature operation of the elliptic birdcage with a conventional hybrid combiner. Insight gained from the transformation is also used to analyze field homogeneity, find the optimal RF shield shape, and specify component values to produce the correct current distribution in practice. Measurements and images from a 16-leg elliptic birdcage coil at both low and high frequencies show good quadrature performance, homogeneity, and sensitivity.

  14. Magnetically Damped Furnace Bitter Magnet Coil 1

    Science.gov (United States)

    Bird, M. D.

    1997-01-01

    A magnet has been built by the National High Magnetic Field Laboratory for NASA on a cost reimbursement contract. The magnet is intended to demonstrate the technology and feasibility of building a magnet for space based crystal growth. A Bitter magnet (named after Francis Bitter, its inventor) was built consisting of four split coils electrically in series and hydraulically in parallel. The coils are housed in a steel vessel to reduce the fringe field and provide some on-axis field enhancement. The steel was nickel plated and Teflon coated to minimize interaction with the water cooling system. The magnet provides 0.14 T in a 184 mm bore with 3 kW of power.

  15. DC SQUIDS with planar input coils

    Energy Technology Data Exchange (ETDEWEB)

    Pegrum, C.M.; Donaldson, G.B.; Hutson, D.; Tugwell, A.

    1985-03-01

    We describe the key parts of our recent work to develop a planar thin-film DC SQUID with a closely-coupled spiral input coil. Our aim has been to make a device that is superior to present RF SQUID sensors in terms of sensitivity and long-term reliability. To be compatible with an RF SQUID the inductance of the input coils must be relatively large, typically 2..mu..H, and the input noise current in the white noise region should be below 10pA Hz /SUP -1/2/ . A low level of 1/f noise is also necessary for many applications and should be achieved without the use of complex noisecancelling circuitry. Our devices meet these criteria. We include a description of work on window and edge junction fabrication using ion beam cleaning, thermal oxidation and RF plasma processing.

  16. 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.

  17. Mechanical Resonances of Helically Coiled Carbon Nanowires

    Science.gov (United States)

    Saini, D.; Behlow, H.; Podila, R.; Dickel, D.; Pillai, B.; Skove, M. J.; Serkiz, S. M.; Rao, A. M.

    2014-07-01

    Despite their wide spread applications, the mechanical behavior of helically coiled structures has evaded an accurate understanding at any length scale (nano to macro) mainly due to their geometrical complexity. The advent of helically coiled micro/nanoscale structures in nano-robotics, nano-inductors, and impact protection coatings has necessitated the development of new methodologies for determining their shear and tensile properties. Accordingly, we developed a synergistic protocol which (i) integrates analytical, numerical (i.e., finite element using COMSOL®) and experimental (harmonic detection of resonance; HDR) methods to obtain an empirically validated closed form expression for the shear modulus and resonance frequency of a singly clamped helically coiled carbon nanowire (HCNW), and (ii) circumvents the need for solving 12th order differential equations. From the experimental standpoint, a visual detection of resonances (using in situ scanning electron microscopy) combined with HDR revealed intriguing non-planar resonance modes at much lower driving forces relative to those needed for linear carbon nanotube cantilevers. Interestingly, despite the presence of mechanical and geometrical nonlinearities in the HCNW resonance behavior the ratio of the first two transverse modes f2/f1 was found to be similar to the ratio predicted by the Euler-Bernoulli theorem for linear cantilevers.

  18. Numerical dosimetry of transcranial magnetic stimulation coils

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2014-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique capable of stimulating neurons by means of electromagnetic induction. TMS can be used to map brain function and shows promise for the diagnosis and treatment of neurological and psychiatric disorders. Calculation of fields induced in the brain are necessary to accurately identify stimulated neural tissue during TMS. This allows the development of novel TMS coil designs capable of stimulating deeper brain regions and increasing the localization of stimulation that can be achieved. We have performed numerical calculations of magnetic and electric field with high-resolution anatomically realistic human head models to find these stimulated brain regions for a variety of proposed TMS coil designs. The realistic head models contain heterogeneous tissue structures and electrical conductivities, yielding superior results to those obtained from the simplified homogeneous head models that are commonly employed. The attenuation of electric field as a function of depth in the brain and the localization of stimulating field have been methodically investigated. In addition to providing a quantitative comparison of different TMS coil designs the variation of induced field between subjects has been investigated. We also show the differences in induced fields between adult, adolescent and child head models to preemptively identify potential safety issues in the application of pediatric TMS.

  19. The coiling of electrified liquid jets

    Science.gov (United States)

    Rivero Rodriguez, Javier; Pérez-Saborid, Miguel

    2013-11-01

    We have carried out a numerical study of the coiling regime which takes place when an electrified liquid jet issuing from an orifice drilled in a metal plate electrode reaches the counter electrode. Based on the slenderness assumption, we have derived the set of one-dimensional dynamical equations by averaging the underlying balance laws over the jet cross sections (Cosserat rod model). Therefore, our equations and boundary conditions are related to those obtained by N.M. Ribe (Ann. Rev Fluid Mech., 2012) for the coiling of liquid ropes, but including electrostatic effects. In a first approach, we have simplified the electrical terms entering the problem by assuming a constant external electric field between electrodes, and that the charges are convected by the jet surface interacting electrostatically with each other via the local interaction approximation (Yarin et al., 2001). We have numerically investigated the problem in order to analize how the coiling regime depends on the dimensionless parameters of the problem, i.e., the Reynolds number, the electrical Bond number and the capillary number. In particular, we have found that both the displacement of the centerline of the jet and its cross-sectional stretching greatly depend on the electrostatic effects. Thanks to the MINECO (Spain) for partial support under grant DPI2010-20450-C03-02.

  20. Finite Element Analyses and Instrumentation Layout for Single Coil Testing of TF Coils in HT-7U

    Institute of Scientific and Technical Information of China (English)

    陈文革; 翁佩德

    2003-01-01

    The HT-7U tokamak is a magnetically-confined full superconducting fusion device,consisting of superconducting toroidal field (TF) coils and superconducting poloidal field (PF)coils. These coils are wound with cable-in-conductor (CICC) which is based on UNK NbTi wiresmade in Russian [1]. A single D-shaped toroidal field magnet coil will be tested for large andexpensive magnets systems before assembling them in the toroidal configuration. This paperdescribes the layout of the instrumentation for a superconducting test facility based on the resultsof a finite element modeling of the single coil of toroidal magnetic field (TF) coils in HT-7Utokamak device. At the same time, the design of coil support structure in the test facility isparticularly discussed in some detail.

  1. Design of Electromagnetic Moving-coil type Voice Coil Motor for Scanning mirror of Barcode reader

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Bu Hyun; Lee, Jeong Woo; Shim, Hyun Ho; Park, Sang Goo [Hanbat National Univ., Daejeon (Korea, Republic of); Lee, Seung Yop [Sogang Univ., Seoul (Korea, Republic of)

    2016-01-15

    A voice coil actuator with moving coil type for scanning mirror system of barcode reader has been developed. The actuator has a simple structure including a magnet, a coil and a pin. The performance of the actuator is analyzed by a linearized theoretical model. And the dynamic performance of the proposed actuator is predicted through motor constant and restoring constant obtained by finite element simulations. The theoretical model was verified by the prototype which has 64 Hz resonance frequency and 60 deg reflecting angle. We also discovered that that 3 V input can make the actuator rotate over 61.8 deg reflecting angle at 50 Hz resonance frequency. The proposed actuator can simplify its driving configuration because of its implementation of open-loop control.

  2. 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.

  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. Thermodynamics of helix-coil transitions studied by multicanonical algorithms

    CERN Document Server

    Okamoto, Y; Okamoto, Yuko; Hansmann, Ulrich H.E.

    1995-01-01

    Thermodynamics of helix-coil transitions in amino-acid homo-oligomers are studied by the recently proposed multicanonical algorithms. Homo-oligomers of length 10 are considered for three characteristic amino acids, alanine (helix former), valine (helix indifferent), and glycine (helix breaker). For alanine other lengths (15 and 20) are also considered in order to examine the length dependence. From one multicanonical production run with completely random initial conformations, we have obtained the lowest-energy conformations and various thermodynamic quantities (average helicity, Zimm-Bragg $s$ and $\\sigma$ parameters, free energy differences between helix and coil states, etc.) as functions of temperature. The results confirm the fact that alanine is helix-forming, valine is helix-indifferent, and glycine is helix-breaking.

  5. 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.

  6. Nucleocapsid formation and RNA synthesis of Marburg virus is dependent on two coiled coil motifs in the nucleoprotein

    Directory of Open Access Journals (Sweden)

    Lander Angelika

    2007-10-01

    Full Text Available Abstract The nucleoprotein (NP of Marburg virus (MARV is responsible for the encapsidation of viral genomic RNA and the formation of the helical nucleocapsid precursors that accumulate in intracellular inclusions in infected cells. To form the large helical MARV nucleocapsid, NP needs to interact with itself and the viral proteins VP30, VP35 and L, which are also part of the MARV nucleocapsid. In the present study, a conserved coiled coil motif in the central part of MARV NP was shown to be an important element for the interactions of NP with itself and VP35, the viral polymerase cofactor. Additionally, the coiled coil motif was essential for the formation of NP-induced intracellular inclusions and for the function of NP in the process of transcription and replication of viral RNA in a minigenome system. Transfer of the coiled coil motif to a reporter protein was sufficient to mediate interaction of the constructed fusion protein with the N-terminus of NP. The coiled coil motif is bipartite, constituted by two coiled coils which are separated by a flexible linker.

  7. The heterotrimeric laminin coiled-coil domain exerts anti-adhesive effects and induces a pro-invasive phenotype.

    Science.gov (United States)

    Santos-Valle, Patricia; Guijarro-Muñoz, Irene; Cuesta, Angel M; Alonso-Camino, Vanesa; Villate, Maider; Alvarez-Cienfuegos, Ana; Blanco, Francisco J; Sanz, Laura; Alvarez-Vallina, Luis

    2012-01-01

    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.

  8. Retrieval of unintended migrated detached coil: case report.

    Science.gov (United States)

    Oh, Jiwoong; Kim, Jongyun; Hong, Sunki; Hu, Chul; Pyen, Jinsu; Whang, Kum; Cho, Sungmin; You, Do-Sung

    2014-09-01

    Owing to the rapid development of intervention techniques and devices, endovascular coil embolization of cerebral arteries has become standardized. It is particularly preferred when a patient presents with an unruptured intracranial aneurysm of the posterior communicating artery (PcomA). However, the risk of thrombogenic complications of the coil migration may also result in a large cerebral infarction. When coil migration occurs during embolization, a procedure for removal of the embolic coil should be performed immediately. We experienced a clinically rare case of migration of a framing coil to the distal middle cerebral artery aneurysm during endovascular embolization of an unruptured PcomA aneurysm. The migrated coil was barely retrieved using snare techniques.

  9. Toroid cavity/coil NMR multi-detector

    Science.gov (United States)

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  10. Effects of coil length on tube compression in electromagnetic forming

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of the length of solenoid coil on tube compression in electromagnetic forming were investigated either by theory analysis or through sequential coupling numerical simulation. The details of the electromagnetic and the mechanical models in the simulation were described. The results show that the amplitude of coil current waveform and the current frequency decrease with the increase of the coil length. And the peak value of magnetic pressure is inversely proportional to the coil length. The distribution of the magnetic force acting on the tube is inhomogeneous while the tube is longer than the coil. The shortened coil length causes the increases of the maximum deformation and energy efficiency. The numerically calculated result and the experimental one of the final tube profile are in good agreement.

  11. Ferrite core non-linearity in coils for magnetic neurostimulation.

    Science.gov (United States)

    RamRakhyani, Anil Kumar; Lazzi, Gianluca

    2014-10-01

    The need to correctly predict the voltage across terminals of mm-sized coils, with ferrite core, to be employed for magnetic stimulation of the peripheral neural system is the motivation for this work. In such applications, which rely on a capacitive discharge on the coil to realise a transient voltage curve of duration and strength suitable for neural stimulation, the correct modelling of the non-linearity of the ferrite core is critical. A demonstration of how a finite-difference model of the considered coils, which include a model of the current-controlled inductance in the coil, can be used to correctly predict the time-domain voltage waveforms across the terminals of a test coil is presented. Five coils of different dimensions, loaded with ferrite cores, have been fabricated and tested: the measured magnitude and width of the induced pulse are within 10% of simulated values.

  12. Coils and transformers - often used but seldomly explained correctly

    CERN Document Server

    Lenz, Michael

    2011-01-01

    The devices coil and transformer are subjects of interest in numerous schoolbooks, in introductory scientific textbooks of physics and engineering, and in laboratory courses at universities. Many descriptions, however, draw a somewhat distorted picture of the underlying physical mechanisms and provide half-knowledge or even clear misconceptions that should not be left uncommented and are therefore studied in detail: (1) Primary and secondary voltage at a transformer have a different sign. (2) Electromagnetic induction is the only mechanism of importance for coils and transformers. (3) The terminal voltage at coils and transformers is compensated by the so-called "induced voltage" (emf), which explains why Kirchhoff's voltage law also applies to coils and transformers. (4) The cores of coils and transformers are used for their ability to store energy. Energy is transported from the primary to the secondary coil within the magnetic core. (5) The stray magnetic and electric fields are sencondary effects not havi...

  13. Improving heat transfer in stirred tanks cooled by helical coils

    Directory of Open Access Journals (Sweden)

    S.M.C.P. Pedrosa

    2003-06-01

    Full Text Available Stirred Tank Reactors are extensively used in chemical industries. When they are used for highly exothermic reactions, jackets or coils are employed for heat removal. Internal coils can be either helical or axial and they considerably affect the flow inside the reactor because they impose an additional resistance to flow circulation. The aim of this work is to show that the design of vessels cooled by helical coils can be further improved. The design of these reactors follows very much the geometry proposed by Oldshue and Gretton (1954, and some minor modifications in the coil arrangements are likely to improve internal circulation inside these vessels mainly in the region between coils and wall of the vessel. Results show a gain in performance when small alterations are made specially in the shape of the coil arrangement.

  14. Experimental Study of Free Convection in Coiled Tube Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Harith Mohammed

    2013-05-01

    Full Text Available An experimental study has been conducted on steady-state natural convection heat transfer from helical coil tubes in vertical orientation. Water was used as a bath liquid without any mixing and cold water was used as a coolant fluid. A straight copper tube of 6 mm ID, 8 mm OD and 3 m length was bend to fabricate the helical coil. Four coils are used in this experiment has different curvature ratios and pitches. The data were correlated using tube diameter as the characteristic length. The results show that the overall heat transfer coefficient and Nusselt number increase when the flow rate of coolant and curvature ratio increase. The effect of coil pitch was investigated and the results show that when of the coil pitch (angle of inclination increases Nusselt number increase. A correlation was presented to calculate the outside average Nusselt number of coil.

  15. Performance of an induction coil gun

    Energy Technology Data Exchange (ETDEWEB)

    Shokair, I.R.; Cowan, M.; Kaye, R.J.; Marder, B.M.

    1993-10-01

    Performance of an electromagnetic induction launcher is considered for three types of armatures. These are: Solid, 1-element wound and 16-element wound aluminum ar natures. The one element wound armature has uniform current density throughout. Because of the radial distribution of the current density, the wound armature can withstand field reversal (working against embedded flux in the armature) and still maintain low temperature. Slingshot simulations were performed, for several configurations. Best performance was obtained for a single element wound armature with two field reversals. For a 60 kg projectile, 10.5 cm coil inner radius and 5.5 cm coil build, the velocity after 50 meters of launcher length (670 stages) exceeded 3.5 km/sec with an overall efficiency of about 45%. For the same parameters the solid and 16-element wound armatures reach a velocity of about 3.3 km/sec after 800 stages (60 meters of launcher length) but without field reversal. A velocity of 3.5 km/sec is possible after 60 meters of launcher length with the 16-element wound armature with one field reversal, but the temperature is close to the melting temperature of aluminum. In all simulations with a solid armature, melting of some of the surface material occurs. However, it is shown that most of the melting occurs after contribution has been made to the forward going pressure, that is, melting does not affect the electrical performance of the launcher. The effect of coil firing tune jitter on launcher performance is also considered and is found to be very small for realistic perturbations. For {plus_minus}2 {mu}-secs random jitter, the reduction in the final velocity for a 60 meter launcher with a solid armature is less than 0.1% and the increase in temperature is only 2%. This result holds for all types of armatures.

  16. Intelligent Control on Hot Strip Coiling Temperature

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new intelligent control scheme for hot strip coiling temperature is presented. In this scheme, the prediction model of finishing temperature and the presetting model of main cooling zone are establish based on BP neural network, the feed-forward open-loop control model of main cooling zone is constructed based on T-S fuzzy neural network, a new improved structure of T-S fuzzy neural network is developed, and the feedback close-loop control model of precision cooling zone is obtained based on fuzzy control. The effectiveness of the proposed scheme has been demonstrated by computer simulation with a satisfactory result.

  17. Extreme acoustic metamaterial by coiling up space.

    Science.gov (United States)

    Liang, Zixian; Li, Jensen

    2012-03-16

    We show that by coiling up space using curled perforations, a two-dimensional acoustic metamaterial can be constructed to give a frequency dispersive spectrum of extreme constitutive parameters, including double negativity, a density near zero, and a large refractive index. Such an approach has band foldings at the effective medium regime without using local resonating subwavelength structures, while the principle can be easily generalized to three dimensions. Negative refraction with a double negative prism and tunneling with a density-near-zero metamaterial are numerically demonstrated.

  18. Sound Coiled-Tubing Drilling Practices

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas; Deskins, Greg (Maurer Technology Inc.); Ward, Stephen L. (Advantage Energy Services Ltd); Hightower, Mel

    2001-09-30

    This Coiled-Tubing Drilling (CTD) Sound Practices Manual provides tools needed by CTD engineers and supervisors to plan, design and perform safe, successful CTD operations. As emphasized throughout, both careful planning and attention to detail are mandatory for success. A bibliography of many useful CTD references is presented in Chapter 6. This manual is organized according to three processes: 1) Pre-Job Planning Process, 2) Operations Execution Process, and 3) Post-Job Review Process. Each is discussed in a logical and sequential format.

  19. MRI surface-coil pair with strong inductive coupling.

    Science.gov (United States)

    Mett, Richard R; Sidabras, Jason W; Hyde, James S

    2016-12-01

    A novel inductively coupled coil pair was used to obtain magnetic resonance phantom images. Rationale for using such a structure is described in R. R. Mett et al. [Rev. Sci. Instrum. 87, 084703 (2016)]. The original rationale was to increase the Q-value of a small diameter surface coil in order to achieve dominant loading by the sample. A significant improvement in the vector reception field (VRF) is also seen. The coil assembly consists of a 3-turn 10 mm tall meta-metallic self-resonant spiral (SRS) of inner diameter 10.4 mm and outer diameter 15.1 mm and a single-loop equalization coil of 25 mm diameter and 2 mm tall. The low-frequency parallel mode was used in which the rf currents on each coil produce magnetic fields that add constructively. The SRS coil assembly was fabricated and data were collected using a tissue-equivalent 30% polyacrylamide phantom. The large inductive coupling of the coils produces phase-coherency of the rf currents and magnetic fields. Finite-element simulations indicate that the VRF of the coil pair is about 4.4 times larger than for a single-loop coil of 15 mm diameter. The mutual coupling between coils influences the current ratio between the coils, which in turn influences the VRF and the signal-to-noise ratio (SNR). Data on a tissue-equivalent phantom at 9.4 T show a total SNR increase of 8.8 over the 15 mm loop averaged over a 25 mm depth and diameter. The experimental results are shown to be consistent with the magnetic resonance theory of the emf induced by spins in a coil, the theory of inductively coupled resonant circuits, and the superposition principle. The methods are general for magnetic resonance and other types of signal detection and can be used over a wide range of operating frequencies.

  20. An autoinhibited coiled-coil design strategy for split-protein protease sensors.

    Science.gov (United States)

    Shekhawat, Sujan S; Porter, Jason R; Sriprasad, Akshay; Ghosh, Indraneel

    2009-10-28

    Proteases are widely studied as they are integral players in cell-cycle control and apoptosis. We report a new approach for the design of a family of genetically encoded turn-on protease biosensors. In our design, an autoinhibited coiled-coil switch is turned on upon proteolytic cleavage, which results in the complementation of split-protein reporters. Utilizing this new autoinhibition design paradigm, we present the rational construction and optimization of three generations of protease biosensors, with the final design providing a 1000-fold increase in bioluminescent signal upon addition of the TEV protease. We demonstrate the generality of the approach utilizing two different split-protein reporters, firefly luciferase and beta-lactamase, while also testing our design in the context of a therapeutically relevant protease, caspase-3. Finally, we present a dual protease sensor geometry that allows for the use of these turn-on sensors as potential AND logic gates. Thus, these studies potentially provide a new method for the design and implementation of genetically encoded turn-on protease sensors while also providing a general autoinhibited coiled-coil strategy for controlling the activity of fragmented proteins.

  1. Design of a single-chain polypeptide tetrahedron assembled from coiled-coil segments.

    Science.gov (United States)

    Gradišar, Helena; Božič, Sabina; Doles, Tibor; Vengust, Damjan; Hafner-Bratkovič, Iva; Mertelj, Alenka; Webb, Ben; Šali, Andrej; Klavžar, Sandi; Jerala, Roman

    2013-06-01

    Protein structures evolved through a complex interplay of cooperative interactions, and it is still very challenging to design new protein folds de novo. Here we present a strategy to design self-assembling polypeptide nanostructured polyhedra based on modularization using orthogonal dimerizing segments. We designed and experimentally demonstrated the formation of the tetrahedron that self-assembles from a single polypeptide chain comprising 12 concatenated coiled coil-forming segments separated by flexible peptide hinges. The path of the polypeptide chain is guided by a defined order of segments that traverse each of the six edges of the tetrahedron exactly twice, forming coiled-coil dimers with their corresponding partners. The coincidence of the polypeptide termini in the same vertex is demonstrated by reconstituting a split fluorescent protein in the polypeptide with the correct tetrahedral topology. Polypeptides with a deleted or scrambled segment order fail to self-assemble correctly. This design platform provides a foundation for constructing new topological polypeptide folds based on the set of orthogonal interacting polypeptide segments.

  2. Double Negativity in 3D Space Coiling Metamaterials

    Science.gov (United States)

    Maurya, Santosh K.; Pandey, Abhishek; Shukla, Shobha; Saxena, Sumit

    2016-09-01

    Metamaterials displaying negative refractive index has remarkable potential to facilitate the manipulation of incident waves for wide variety of applications such as cloaking, superlensing and the like. Space-coiling approach is a recently explored technique to achieve extreme properties. The space coiling phenomena cause less energy absorption as compared to local resonating phenomena for obtaining extreme parameters. Here we show extreme properties in doubly negative 3D space coiling acoustic metamaterials. Frequency dispersive spectrum of extreme constitutive parameters has been calculated for 2D maze and 3D space coiling labyrinthine structure. This is in good agreement to the calculated acoustic band dispersion.

  3. Performance verification tests of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Murakami, Haruyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-11-15

    Highlights: • The performance of the JT-60SA CS model coil was verified. • The CS model coil comprised a quad-pancake wound with a Nb{sub 3}Sn CIC conductor. • The CS model coil met the design requirements. - Abstract: As a final check of the coil manufacturing method of the JT-60 Super Advanced (JT-60SA) central solenoid (CS), we verified the performance of a CS model coil. The model coil comprised a quad-pancake wound with a Nb{sub 3}Sn cable-in-conduit conductor. Measurements of the critical current, joint resistance, pressure drop, and magnetic field were conducted in the verification tests. In the critical-current measurement, the critical current of the model coil coincided with the estimation derived from a strain of −0.62% for the Nb{sub 3}Sn strands. As a result, critical-current degradation caused by the coil manufacturing process was not observed. The results of the performance verification tests indicate that the model coil met the design requirements. Consequently, the manufacturing process of the JT-60SA CS was established.

  4. Synthesis, characterisation and applications of coiled carbon nanotubes.

    Science.gov (United States)

    Hanus, Monica J; Harris, Andrew T

    2010-04-01

    Coiled carbon nanotubes are helical carbon structures formed when heptagonal and pentagonal rings are inserted into the hexagonal backbone of a 'straight' nanotube. Coiled carbon nanotubes have been reported with both regular and irregular helical structures. In this work the structure, growth mechanism(s), synthesis, properties and potential applications of coiled carbon nanotubes are reviewed. Published data suggests that coiled carbon nanotube synthesis occurs due to nonuniform extrusion of carbon from a catalyst surface. To date, coiled carbon nanotubes have been synthesised using catalyst modification techniques including: (i) the addition of S or P containing compounds during synthesis; (ii) the use of binary or ternary metal catalysts; (iii) the use of microwaves to create a local temperature gradient around individual catalyst particles and; (iv) the use of pH control during catalyst preparation. In most instances coiled carbon nanotubes are produced as a by-product; high yield and/or large-scale synthesis of coiled carbon nanotubes remains problematic. The qualitative analysis of coiled carbon nanotubes is currently hindered by the absence of specific characterisation data in the literature, e.g., oxidation profiles measured by thermogravimetric analysis and Raman spectra of pure coiled carbon nanotube samples.

  5. The Whole Elephant: A Synoptic View of Liquid Rope Coiling

    Science.gov (United States)

    Ribe, Neil

    2016-11-01

    Liquid rope coiling is the instability that occurs when e.g. a thin stream of honey is poured onto toast. While we now have a fine-grained understanding of each of the four principal coiling modes (viscous, gravitational, inertio-gravitational and inertial), we still lack a global view of how the modes cohere to form a larger whole. Using a numerical continuation procedure, I determine how the dimensionless coiling frequency depends on the dimensionless fall height and flow rate, for several values of the dimensionless nozzle diameter. Starting with the onset of coiling, I propose a purely geometrical definition of the critical surface between coiling and no coiling as the locus of points where the radius a1 of the rope at the contact point is just equal to the coil radius R. Coiling with a1 > R is impossible because the rope would intersect itself. I characterize the asymptotic limits of the critical surface as well as the structure of the supercritical volume inside that surface. The procedure reveals a new mode of coiling onset that has not yet been identified.

  6. Double Negativity in 3D Space Coiling Metamaterials.

    Science.gov (United States)

    Maurya, Santosh K; Pandey, Abhishek; Shukla, Shobha; Saxena, Sumit

    2016-09-21

    Metamaterials displaying negative refractive index has remarkable potential to facilitate the manipulation of incident waves for wide variety of applications such as cloaking, superlensing and the like. Space-coiling approach is a recently explored technique to achieve extreme properties. The space coiling phenomena cause less energy absorption as compared to local resonating phenomena for obtaining extreme parameters. Here we show extreme properties in doubly negative 3D space coiling acoustic metamaterials. Frequency dispersive spectrum of extreme constitutive parameters has been calculated for 2D maze and 3D space coiling labyrinthine structure. This is in good agreement to the calculated acoustic band dispersion.

  7. Magnetic resonance imaging receiver coil decoupling using circumferential shielding structures.

    Science.gov (United States)

    Yeh, Jhy-Neng Tasso; Fa-Hsuan Lin

    2016-08-01

    We propose a flexible phased-array design using circular coils with circumferential shielding structure to achieve robust decoupling between coil elements when the array is either bended or on a flat plane. Two types of circumferential shielding were tested through numerical simulation and imaging experiment. The results demonstrated that our arrays have good decoupling between coils when they are on a curved surface with S21 coil array. Future work will empirically construct a multi-channel array with the number of channel matched to commercial phased array in order to validate the performance in vivo.

  8. Dirty air conditioners: Energy implications of coil fouling

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, Jeffrey; Walker, Iain; Sherman, Max

    2002-03-01

    Residential air conditioning is responsible for a substantial amount of peak electrical demand and energy consumption throughout most of the United States. Coil fouling, the deposition of indoor dusts and other particulate matter on evaporator heat exchangers, increases system pressure drop and, correspondingly, decreases system air flow and air conditioner performance. In this paper, we apply experimental and simulation results describing particle deposition on evaporator coils as well as research about indoor particle and dust concentrations to determine coil fouling rates. The results suggest that typical coils foul enough to double evaporator pressure drop in about 7.5 years, much sooner than the expected 15-30 year life time for an evaporator coil. The most important parameters in determining coil fouling times are the efficiency of the filter and indoor particle concentrations, although filter bypass and duct and coil design are important as well. The reduced air flows that result from coil fouling cause typical efficiency and capacity degradations of less than 5%, however they can be much greater for marginal systems or extreme conditions. These energy issues, as well as possible indoor air quality issues resulting from fouling by biological aerosols, suggest that regular coil cleaning to ameliorate low flow and the elimination of filter bypass should be an important part of residential air conditioning commissioning and maintenance practices.

  9. Developments of RF Coil for P in vivo NMR Spectroscopy .

    Directory of Open Access Journals (Sweden)

    S. Khushu

    1993-07-01

    Full Text Available RF receiver coils are very important parts of an NMR System. The design of these coils is very critical and has a dramatic effect on the SNR of the NMR signal and are generally developed in TRA/REC mode. This paper reports the developments of a 3.5 cm TRA/REC 26 MHz RF coil for P spectroscopy of small organs like thyroid. The coil is small in size, fits well in the neck for thyroid spectroscopy and is successfully working with the 1.5 tesla whole body Superconducting NMR System available at INMAS.

  10. Analysis of the cooldown of the ITER central solenoid model coil and insert coil

    Science.gov (United States)

    Bonifetto, R.; Brighenti, A.; Isono, T.; Martovetsky, N.; Kawano, K.; Savoldi, L.; Zanino, R.

    2017-01-01

    A series of superconducting insert coils (ICs) made of different materials has been tested since 2000 at JAEA Naka in the bore of the central solenoid model coil at fields up to 13 T and currents up to several tens of kA, fully representative of the ITER operating conditions. Here we focus on the 2015 test of the presently last IC of the series, the central solenoid (CS) insert coil, which was aimed at confirming the performance and properties of the Nb3Sn conductor, manufactured in Japan and used to wind the ITER CS modules in the US. As typical for these large scale applications, the cooldown (CD) from ambient to supercritical He temperature may take a long time, of the order of several weeks, so that it should be useful, also in the perspective of future IC tests, to optimize it. To that purpose, a comprehensive CD model implemented in the 4C code is developed and presented in this paper. The model is validated against the experimental data of an actual CD scenario, showing a very good agreement between simulation and measurements, from 300 to 4.5 K. The maximum temperature difference across the coil, which can only be roughly estimated from the measurements, is then extracted from the results of the simulation and shown to be much larger than the maximum value of 50 K, prescribed on the basis of the allowable thermal stress on the materials. An optimized CD scenario is finally designed using the model for the initial phase of the CD between 300 and 80 K, which allows reducing the needed time by ∼20%, while still satisfying the major constraints. Recommendations are also given for a better location/choice of the thermometers to be used for the monitoring of the maximum temperature difference across the coil.

  11. The Search Coil Magnetometer for THEMIS

    Science.gov (United States)

    Roux, A.; Le Contel, O.; Coillot, C.; Bouabdellah, A.; de La Porte, B.; Alison, D.; Ruocco, S.; Vassal, M. C.

    2008-12-01

    THEMIS instruments incorporate a tri-axial Search Coil Magnetometer (SCM) designed to measure the magnetic components of waves associated with substorm breakup and expansion. The three search coil antennas cover the same frequency bandwidth, from 0.1 Hz to 4 kHz, in the ULF/ELF frequency range. They extend, with appropriate Noise Equivalent Magnetic Induction (NEMI) and sufficient overlap, the measurements of the fluxgate magnetometers. The NEMI of the searchcoil antennas and associated pre-amplifiers is smaller than 0.76 pT /sqrt{Hz} at 10 Hz. The analog signals produced by the searchcoils and associated preamplifiers are digitized and processed inside the Digital Field Box (DFB) and the Instrument Data Processing Unit (IDPU), together with data from the Electric Field Instrument (EFI). Searchcoil telemetry includes waveform transmission, FFT processed data, and data from a filter bank. The frequency range covered depends on the available telemetry. The searchcoils and their three axis structures have been precisely calibrated in a calibration facility, and the calibration of the transfer function is checked on board, usually once per orbit. The tri-axial searchcoils implemented on the five THEMIS spacecraft are working nominally.

  12. A novel method for coiled tubing installation

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Peter J. [2H Offshore, Houston, TX (United States); Tibbetts, David [Aquactic Engineering and Construction Ltd., Aberdeen (United Kingdom)

    2009-12-19

    Installation of flexible pipe for offshore developments is costly due to the physical cost of the flexible pipe, expensive day rates and the availability of suitable installation vessels. Considering the scarcity of flexible pipe in today's increasingly demanding and busy market, operators are seeking a cost effective solution for installing piping in a range of water depths using vessels which are readily on hand. This paper describes a novel approach to installing reeled coiled tubing, from 1 inch to 5 inch diameter, from the back of a small vessel in water depths from 40 m up to around 1000 m. The uniqueness of the system is the fact that the equipment design is modular and compact. This means that when disassembled, it fits into standard 40 ft shipping containers, and the size allows it to be installed on even relatively small vessels of opportunity, such as anchor handling or installation vessels, from smaller, and cheaper quay side locations. Such an approach is the ideal solution to the problem faced by operators, in that it allows the installation of cheaper, readily available coiled tubing, from cost-effective vessels, which do not need to transit to a pick up the system. (author)

  13. Four-stranded coiled-coil elastic protein in the byssus of the giant clam, Tridacna maxima.

    Science.gov (United States)

    Miserez, Ali; Li, Youli; Cagnon, Joel; Weaver, James C; Waite, J Herbert

    2012-02-13

    An elastic protein with a secondary structure distinct from all well-known load-bearing proteins is found in the byssus of the giant clam, Tridacna maxima . The byssus consists of a bundle of hundreds of individual threads, each measuring about about 100 μm in diameter, which exhibit a tendon-like mechanical response. The amino acid composition of Tridacna byssus, however, is unlike tendon collagen, lacking high glycine, proline, and hydroxyproline. Wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) measurements suggest that the constituent nanofibrils of the byssal threads are distinct from known secondary structure motifs previously reported for elastic proteins including the collagen triple-helix, the β-sheet nanocrystalline domains of silks, or the double-stranded coiled-coil regions of intermediate filaments. Instead, X-ray diffraction data indicate a structural organization in which four coiled-coil α-helices form a stable rope-like structure, which then further pack in a pseudohexagonal lattice to form nanofibrils. Amino acid composition analysis shows unusually high concentrations of acidic as well as basic residues, suggesting that the four-helix structure is stabilized by strong ionic interactions between oppositely charged residues in neighboring strands. The composition also suggests additional stabilization by disulfide cross-linking. On a larger scale, scanning and conventional transmission electron microscope (STEM and TEM) observations indicate that the nanofibrils exhibit an alternating periodicity of about 500 nm along the axial direction. A molecular model that combines the mechanical properties with the structural characteristics of the Tridacna byssal threads is proposed.

  14. Solutions for Safe Hot Coil Evacuation and Coil Handling in Case of Thick and High Strength Steel

    Directory of Open Access Journals (Sweden)

    Sieberer Stefan

    2016-01-01

    Full Text Available Currently hot rolling plants are entering the market segment for thick gauges and high strength steel grades where the elastic bending property of the strip leads to internal forces in the coil during coiling operation. The strip tends to open. Primetals is investigating several possibilities to facilitate safe coil evacuation and coil handling under spring-back conditions. The contribution includes finite element models of such mechanical solutions. Results of parameter variation and stability limits of case studies are presented in the paper.

  15. Self-assembly of designed coiled coil peptides studied by small-angle X-ray scattering and analytical ultracentrifugation

    DEFF Research Database (Denmark)

    Malik, Leila; Nygaard, Jesper; Christensen, Niels Johan;

    2013-01-01

    α-Helical coiled coil structures, which are noncovalently associated heptad repeat peptide sequences, are ubiquitous in nature. Similar amphipathic repeat sequences have also been found in helix-containing proteins and have played a central role in de novo design of proteins. In addition......, they are promising tools for the construction of nanomaterials. Small-angle X-ray scattering (SAXS) has emerged as a new biophysical technique for elucidation of protein topology. Here, we describe a systematic study of the self-assembly of a small ensemble of coiled coil sequences using SAXS and analytical...

  16. Effect of inductive coil shape on sensing performance of linear displacement sensor using thin inductive coil and pattern guide.

    Science.gov (United States)

    Misron, Norhisam; Ying, Loo Qian; Firdaus, Raja Nor; Abdullah, Norrimah; Mailah, Nashiren Farzilah; Wakiwaka, Hiroyuki

    2011-01-01

    This paper discusses the effect of inductive coil shape on the sensing performance of a linear displacement sensor. The linear displacement sensor consists of a thin type inductive coil with a thin pattern guide, thus being suitable for tiny space applications. The position can be detected by measuring the inductance of the inductive coil. At each position due to the change in inductive coil area facing the pattern guide the value of inductance is different. Therefore, the objective of this research is to study various inductive coil pattern shapes and to propose the pattern that can achieve good sensing performance. Various shapes of meander, triangular type meander, square and circle shape with different turn number of inductive coils are examined in this study. The inductance is measured with the sensor sensitivity and linearity as a performance evaluation parameter of the sensor. In conclusion, each inductive coil shape has its own advantages and disadvantages. For instance, the circle shape inductive coil produces high sensitivity with a low linearity response. Meanwhile, the square shape inductive coil has a medium sensitivity with higher linearity.

  17. 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.

  18. Meta-analysis of stent-assisted coiling versus coiling-only for the treatment of intracranial aneurysms.

    Science.gov (United States)

    Phan, Kevin; Huo, Ya R; Jia, Fangzhi; Phan, Steven; Rao, Prashanth J; Mobbs, Ralph J; Mortimer, Alex M

    2016-09-01

    Endovascular coil embolization is a widely accepted and useful treatment modality for intracranial aneurysms. However, the principal limitation of this technique is the high aneurysm recurrence. The adjunct use of stents for coil embolization procedures has revolutionized the field of endovascular aneurysm management, however its safety and efficacy remains unclear. Two independent reviewers searched six databases from inception to July 2015 for trials that reported outcomes according to those who received stent-assisted coiling versus coiling-only (no stent-assistance). There were 14 observational studies involving 2698 stent-assisted coiling and 29,388 coiling-only patients. The pooled immediate occlusion rate for stent-assisted coiling was 57.7% (range: 20.2%-89.2%) and 48.7% (range: 31.7%-89.2%) for coiling-only, with no significant difference between the two (odds ratio [OR}=1.01; 95% confidence intervals [CI}: 0.68-1.49). However, progressive thrombosis was significantly more likely in stent-assisted coiling (29.9%) compared to coiling-only (17.5%) (OR=2.71; 95% CI: 1.95-3.75). Aneurysm recurrence was significantly lower in stent-assisted coiling (12.7%) compared to coiling-only (27.9%) (OR=0.43; 95% CI: 0.28-0.66). In terms of complications, there was no significant difference between the two techniques for all-complications, permanent complications or thrombotic complications. Mortality was significantly higher in the stent-assisted group 1.4% (range: 0%-27.5%) compared to the coiling-only group 0.2% (range: 0%-19.7%) (OR=2.16; 95% CI: 1.33-3.52). Based on limited evidence, stent-assisted coiling shows similar immediate occlusion rates, improved progressive thrombosis and decreased aneurysm recurrence compared to coiling-only, but is associated with a higher mortality rate. Future randomized controlled trials are warranted to clarify the safety of stent-associated coiling.

  19. Simulations of Twin-Box Joints for ITER PF Coils

    NARCIS (Netherlands)

    Ilyin, Y.; Rolando, G.; Nijhuis, A.; Simon, F.; Lim, B.S.; Mitchell, N.; Turck, B.

    2014-01-01

    An ITER Poloidal Field coil winding consists of stacked double pancakes wound with NbTi cable-in-conduit conductors. One of the critical components of the coil is the electrical joint connecting either two conductor lengths within a double pancake or two double pancakes. All joints utilize the twin-

  20. Temperature Profile Measurements During Heat Treatment of BSCCO 2212 Coils

    CERN Document Server

    ,

    2012-01-01

    The temperature profile of two different BSCCO 2212 coils has been analyzed. The profiles are obtained from thermocouples imbedded in the windings during the heat treatment that activates the 2212. The melting and freezing of the 2212 is clearly observed. A model that describes the data and can be used to guide the processing of new coils has been developed.

  1. ATLAS-Lowering the first Barrel Toroid coil

    CERN Multimedia

    CERN Audiovisual Unit

    2004-01-01

    Cranes lowered the first of ATLAS's eight Barrel Toroid coils into the cavern. The part is 25 meters long and the cranes had to hold the 100 tonne coil at a sharp angle while it passed through the 18-meter diameter vertical shaft into the cavern. Then they laid the magnet to a horizontal robust platform. Images from Camera 2

  2. 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...

  3. 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...

  4. Bioaerosol deposition on an air-conditioning cooling coil

    Science.gov (United States)

    Wu, Yan; Chen, Ailu; Luhung, Irvan; Gall, Elliott T.; Cao, Qingliang; Chang, Victor Wei-Chung; Nazaroff, William W.

    2016-11-01

    This study is concerned with the role of a fin-and-tube heat exchanger in modifying microbial indoor air quality. Specifically, depositional losses of ambient bioaerosols and particles onto dry (not cooled) and wet (cool) coil surfaces were measured for different airspeeds passing through the test coil. Total, bacterial and fungal DNA concentrations in condensate water produced by a wet coil were also quantified by means of fluorescent dsDNA-binding dye and qPCR assays. Results revealed that the deposition of bioaerosols and total particles is substantial on coil surfaces, especially when wet and cool. The average deposition fraction was 0.14 for total DNA, 0.18 for bacterial DNA and 0.22 for fungal DNA on the dry coil, increasing to 0.51 for total DNA, 0.50 for bacterial DNA and 0.68 for fungal DNA on the wet coil. Overall, as expected, deposition fractions increased with increasing particle size and increasing airspeed. Deposited DNA was removed from the cooling coil surfaces through the flow of condensing water at a rate comparable to the rate of direct deposition from air. A downward trend of bacterial and fungal DNA measured in condensate water over time provides suggestive evidence of biological growth on heat exchangers during nonoperational times of a ventilation system. This investigation provides new information about bioaerosol deposition onto a conventional fin-and-tube cooling coil, a potentially important factor influencing indoor exposure to microbial aerosols in air-conditioned buildings.

  5. Magnetic field measurements of JT-60SA CS model coil

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Chikaraishi, Hirotaka; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Natsume, Kyohei; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2015-01-15

    Highlights: • Magnetic fields of the JT-60SA CS model coil were measured. • While the coil current was held constant at 20 kA, magnetic fields varied slightly with several different long time constants. • We investigated coils consisting of CIC conductors and having long time constants. - Abstract: In a cold test of the JT-60SA CS model coil, which has a quad-pancake configuration consisting of a Nb{sub 3}Sn cable-in-conduit (CIC) conductor, magnetic fields were measured using Hall sensors. For a holding coil current of 20 kA, measured magnetic fields varied slightly with long time constants in the range 17–571 s, which was much longer than the time constant derived from a measurement using a short straight sample. To validate the measurements, the magnetic fields of the model coil were calculated using a computational model representing the positions of Nb{sub 3}Sn strands inside the CIC conductor. The calculated results were in good agreement with the measurements. Consequently, the validity of the magnetic field measurements was confirmed. Next, we investigated other coils consisting of CIC conductors and having long time constants. The only commonality among the coils was the use of CIC conductors. At present, there is no obvious way to prevent generation of such magnetic-field variations with long time constants.

  6. Impulse and Frequency Response of a Moving Coil Galvanometer.

    Science.gov (United States)

    McNeill, D. J.

    1985-01-01

    Describes an undergraduate laboratory experiment in which a moving coil galvanometer is studied and the electromotive force generated by the swinging coil provides the impulse response information in a form suitable for digitizing and inputing to a microcomputer. Background information and analysis of typical data are included. (JN)

  7. Second Barrel Toroid Coil Installed in ATLAS Cavern

    CERN Multimedia

    Tappern, G.

    The second barrel toroid coil was lowered into the ATLAS Cavern on Friday, 26 November. The operation takes approximately five hours of precision crane and winch operations. Before lowering, several checks are made to ensure that no loose items have been left on the coil which would fall during the lowering down the shaft. This is a very difficult, but very important check, with the first coil in position, and partly below the shaft. After changing the winch tooling on Wednesday December 1st, the coil was lifted, rotated and placed into the feet. The girders which support the coil and the Z direction stops had all been pre-set before putting the coil in the feet. The angle is controlled by an inclinometer. When the final adjustments of position have been made, which will locate the coils at the plus/minus two mm level, the connection beams (voussoirs and struts) will be put in place; this requires a complex shimming procedure. This will lock together the two coils into the feet and forms the foundation for th...

  8. ATLAS-Lowering the first Barrel Toroid coil

    CERN Multimedia

    2004-01-01

    Cranes lowered the first of ATLAS's eight Barrel Toroid coils into the cavern. The part is 25 metres long and the cranes had to hold the 100 tonne coil at a sharp angle while it passed through the 18-metre diameter vertical shaft into the cavern. Then they laid the magnet to a horisontal robust platform. Images from Camera 1

  9. Performance correlation between YBa2Cu3O7-δ coils and short samples for coil technology development

    Science.gov (United States)

    Wang, X.; Dietderich, D. R.; Godeke, A.; Gourlay, S. A.; Marchevsky, M.; Prestemon, S. O.; Sabbi, G. L.

    2016-06-01

    A robust fabrication technology is critical to achieve the high performance in YBa2Cu3O{}7-δ (YBCO) coils as the critical current of the brittle YBCO layer is subject to the strain-induced degradation during coil fabrication. The expected current-carrying capability of the magnet and its temperature dependence are two key inputs to the coil technology development. However, the expected magnet performance is not straightforward to determine because the short-sample critical current depends on both the amplitude and orientation of the applied magnetic field with respect to the broad surface of the tape-form conductor. In this paper, we present an approach to calculate the self-field performance limit for YBCO racetrack coils at 77 and 4.2 K. Critical current of short YBCO samples was measured as a function of the applied field perpendicular to the conductor surface from 0 to 15 T. This field direction limited the conductor critical current. Two double-layer racetrack coils, one with three turns and the other with 10 turns, were wound and tested at 77 and 4.2 K. The test coils reached at least 80% of the expected critical current. The ratio between the coil critical currents at 77 and 4.2 K agreed well with the calculation. We conclude that the presented approach can determine the performance limit in YBCO racetrack coils based on the short-sample critical current and provide a useful guideline for assessing the coil performance and fabrication technology. The correlation of the coil critical current between 77 K and 4.2 K was also observed, allowing the 77 K test to be a cost-effective tool for the development of coil technology.

  10. Impact of coil price knowledge by the operator on the cost of aneurysm coiling. A single center study.

    Science.gov (United States)

    Finitsis, Stephanos; Fahed, Robert; Gaulin, Ian; Roy, Daniel; Weill, Alain

    2017-09-15

    Endovascular treatment of aneurysms with coils is among the most frequent treatments in interventional neuroradiology, and represents an important expense. Each manufacturer has created several types of coils, with prices varying among brands and coil types. The objective of this study was to assess the impact of cost awareness of the exact price of each coil by the operating physician on the total cost of aneurysm coiling. This was a comparative study conducted over 1 year in a single tertiary care center. The reference cohort and the experimental cohort consisted of all aneurysm embolization procedures performed during the first 6 months and the last 6 months, respectively. During the second period, physicians were given an information sheet with the prices of all available coils and were requested to look at the sheet during each procedure with the instruction to try to reduce the total cost of the coils used. Expenses related to the coiling procedures during each period were compared. 77 aneurysms (39 ruptured) in the reference cohort and 73 aneurysms (36 ruptured) in the experimental cohort were treated, respectively. There was no statistically significant difference regarding aneurysm location and mean size. The overall cost of the coiling procedures, the mean number of coils used per procedure, and the median cost of each procedure did not differ significantly between the two cohorts. Awareness of the precise price of coils by operators without any additional measure did not have a scientifically proven impact on the cost of aneurysm embolization. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Temperature dependence of the PER in PM-PCF coil

    Institute of Scientific and Technical Information of China (English)

    Hong Zhao; Meng Chen; Gang Li

    2012-01-01

    A piece of domestic polarization-maintaining photonic crystal fiber (PM-PCF,964 m in length) is made into a fiber coil,and its polarization extinction ratio (PER) is measured in a temperature range of -45-80 ℃ before and after PM-PCF is wound and solidified.A fiber coil made of commercial panda PM fiber (PMF) is also fabricated and measured for comparison.Our experiments show that the PER variation of the PM-PCF coil (2.25 dB) is far smaller than that of the panda PMF coil (10 dB) in the whole temperature range because PM-PCF is intrinsically insensitive to the temperature variation and stress in the fiber coil induced by the winding and solidification process.This characteristic is important for the real application of PM-PCFs in temperature-insensitive fiber interferometers,fiber sensors,and optical fiber gyroscopes.

  12. Vehicle to wireless power transfer coupling coil alignment sensor

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Electromagnetic Design of Superconducting Dipoles Based on Sector Coils

    CERN Document Server

    Todesco, Ezio

    2007-01-01

    We study the coil lay-outs of superconducting dipoles for particle accelerators based on the sector geometry. We show that a simple model based on a sector coil with a wedge allows us to derive an equation giving the short sample field as a function of the aperture, coil width, cable properties and superconducting material. The equation agrees well with the actual results of several dipole coils that have been built in the last 30 years. The improvements due to the grading technique and the iron yoke are also studied. The proposed equation can be used as a benchmark to judge the efficiency of the coil design, and to carry out a global optimization of an accelerator lay-out.

  14. 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.

  15. Dual cervical thoracic coil for spine magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Totterman, S.; Foster, T.H.; Plewes, D.B.; Simon, J.H.; Ekholm, S.; Wicks, A. (Rochester Univ., NY (USA). Dept. of Radiology Rochester Univ., NY (USA). Dept. of Physics and Astronomy)

    The need for repositioning of surface coils and patients in MR examinations of the cervical and thoracic spin prolongs examination time. A new receiver design is proposed which overcomes this problem. The device is composed of two actively decoupled receiver coils mounted on the frame of a Philadelphia collar. These coils may be used separately to image either the thoracic or cervical spine or together to produce larger field-of-view images of the combined region. Signal-to-noise ratios of the separate cervical and thoracic spine images are not degraded as a result of mounting the receivers together. The full cervical and thoracic region is shown to be imaged at a signal-to-noise ratio significantly higher than that afforded by the body coil. A retrospective review of our case load suggests that a time saving could be achieved in approximately 1/3 of spine examinations by using this coil. (orig.).

  16. Nonlinear Dynamics of Coiling in Viscoelastic Jets

    CERN Document Server

    Majmudar, Trushant; Hartt, William; McKinley, Gareth

    2010-01-01

    Instabilities in free surface continuous jets of non-Newtonian fluids, although relevant for many industrial processes, remain less well understood in terms of fundamental fluid dynamics. Inviscid, and viscous Newtonian jets have been studied in great detail; buckling instability in viscous jets leads to regular periodic coiling of the jet that exhibits a non-trivial frequency dependence with the height of the fall. Very few experimental or theoretical studies exist for continuous viscoelastic jets beyond the onset of the first instability. Here, we present a systematic study of the effects of viscoelasticity on the dynamics of free surface continuous jets of surfactant solutions that form worm-like micelles. We observe complex nonlinear spatio-temporal dynamics of the jet and uncover a transition from periodic to doubly-periodic or quasi-periodic to a multi-frequency, possibly chaotic dynamics. Beyond this regime, the jet dynamics smoothly crosses over to exhibit the "leaping shampoo effect" or the Kaye effe...

  17. Transformer current sensor for superconducting magnetic coils

    Science.gov (United States)

    Shen, Stewart S.; Wilson, C. Thomas

    1988-01-01

    A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

  18. Antibody engineering using phage display with a coiled-coil heterodimeric Fv antibody fragment.

    Directory of Open Access Journals (Sweden)

    Xinwei Wang

    Full Text Available A Fab-like antibody binding unit, ccFv, in which a pair of heterodimeric coiled-coil domains was fused to V(H and V(L for Fv stabilization, was constructed for an anti-VEGF antibody. The anti-VEGF ccFv showed the same binding affinity as scFv but significantly improved stability and phage display level. Furthermore, phage display libraries in the ccFv format were constructed for humanization and affinity maturation of the anti-VEGF antibody. A panel of V(H frameworks and V(H-CDR3 variants, with a significant improvement in affinity and expressibility in both E. coli and yeast systems, was isolated from the ccFv phage libraries. These results demonstrate the potential application of the ccFv antibody format in antibody engineering.

  19. De novo designed coiled-coil proteins with variable conformations as components of molecular electronic devices.

    Science.gov (United States)

    Shlizerman, Clara; Atanassov, Alexander; Berkovich, Inbal; Ashkenasy, Gonen; Ashkenasy, Nurit

    2010-04-14

    Conformational changes of proteins are widely used in nature for controlling cellular functions, including ligand binding, oligomerization, and catalysis. Despite the fact that different proteins and artificial peptides have been utilized as electron-transfer mediators in electronic devices, the unique propensity of proteins to switch between different conformations has not been used as a mechanism to control device properties and performance. Toward this aim, we have designed and prepared new dimeric coiled-coil proteins that adopt different conformations due to parallel or antiparallel relative orientations of their monomers. We show here that controlling the conformation of these proteins attached as monolayers to gold, which dictates the direction and magnitude of the molecular dipole relative to the surface, results in quantitative modulation of the gold work function. Furthermore, charge transport through the proteins as molecular bridges is controlled by the different protein conformations, producing either rectifying or ohmic-like behavior.

  20. Treatment of Intracranial Aneurysms: Clipping Versus Coiling.

    Science.gov (United States)

    Liu, Ann; Huang, Judy

    2015-09-01

    Intracranial aneurysms (IAs) have an estimated incidence of up to 10 % and can lead to serious morbidity and mortality. Because of this, the natural history of IAs has been studied extensively, with rupture rates ranging from 0.5 to 7 %, depending on aneurysm characteristics. The spectrum of presentation of IAs ranges from incidental detection to devastating subarachnoid hemorrhage. Although the gold standard imaging technique is intra-arterial digital subtraction angiography, other modalities such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are being increasingly used for screening and treatment planning. Management of these patients depends upon a number of factors including aneurysmal, patient, institutional, and operator factors. The ultimate goal of treating patients with IAs is complete and permanent occlusion of the aneurysm sac in order to eliminate future hemorrhagic risk, while preserving or restoring the patient's neurological function. The most common treatment approaches include microsurgical clipping and endovascular coiling, and multiple studies have compared these two techniques. To date, three large prospective, randomized studies have been done: a study from Finland, International Subarachnoid Aneurysm Trial (ISAT), and the Barrow Ruptured Aneurysm Trial (BRAT). Despite differences in methodology, the results were similar: in patients undergoing coiling, although rates of rebleeding and retreatment are higher, the overall rate of poor outcomes at 12 months was significantly lower. As minimally invasive procedures and devices continue to be refined, endovascular strategies are likely to increase in popularity. However, as long-term outcome studies become available, it is increasingly apparent that they are complementary treatment strategies, with patient selection of critical importance.

  1. The intrinsic factor-vitamin B12 receptor, cubilin, is assembled into trimers via a coiled-coil alpha-helix.

    Science.gov (United States)

    Lindblom, A; Quadt, N; Marsh, T; Aeschlimann, D; Mörgelin, M; Mann, K; Maurer, P; Paulsson, M

    1999-03-05

    A large protein was purified from bovine kidney, using selective extraction with EDTA to solubilize proteins anchored by divalent cation-dependent interactions. An antiserum raised against the purified protein labeled the apical cell surface of the epithelial cells in proximal tubules and the luminal surface of small intestine. Ten peptide sequences, derived from the protein, all matched the recently published sequences for rat (Moestrup, S. K., Kozyraki, R., Kristiansen, M., Kaysen, J. H., Holm Rasmussen, H., Brault, D., Pontillon, F., Goda, F. O., Christensen, E. I., Hammond, T. G., and Verroust, P. J. (1998) J. Biol. Chem. 273, 5235-5242) and human cubilin, a receptor for intrinsic factor-vitamin B12 complexes, identifying the protein as bovine cubilin. In electron microscopy, a three-armed structure was seen, indicating an oligomerization of three identical subunits. This model was supported by the Mr values of about 1,500,000 for the intact protein and 440,000 for its subunits obtained by analytical ultracentrifugation. In a search for a potential assembly domain, we identified a region of heptad repeats in the N-terminal part of the cubilin sequence. Computer-assisted analysis supported the presence of a coiled-coil alpha-helix between amino acids 103 and 132 of the human cubilin sequence and predicted the formation of a triple coiled-coil. We therefore conclude that cubilin forms a noncovalent trimer of identical subunits connected by an N-terminal coiled-coil alpha-helix.

  2. A coiled coil trigger site is essential for rapid binding of synaptobrevin to the SNARE acceptor complex

    DEFF Research Database (Denmark)

    Wiederhold, Katrin; Kloepper, Tobias H; Walter, Alexander M;

    2010-01-01

    to the preformed syntaxin 1.SNAP-25 dimer. Exactly how this step relates to neurotransmitter release is not well understood. Here, we combined different approaches to gain insights into this reaction. Using computational methods, we identified a stretch in synaptobrevin 2 that may function as a coiled coil...

  3. Analysis and experimental study of wireless power transfer with HTS coil and copper coil as the intermediate resonators system

    Science.gov (United States)

    Wang, Xiufang; Nie, Xinyi; Liang, Yilang; Lu, Falong; Yan, Zhongming; Wang, Yu

    2017-01-01

    Intermediate resonator (repeater) between transmitter and receiver can significantly increase the distance of wireless power transfer (WPT) and the efficiency of wireless power transfer. The wireless power transfer via strongly coupled magnetic resonances with an high temperature superconducting (HTS) coil and copper coil as intermediate resonators was presented in this paper. The electromagnetic experiment system under different conditions with different repeating coils were simulated by finite element software. The spatial distribution patterns of magnetic induction intensity at different distances were plotted. In this paper, we examined transfer characteristics with HTS repeating coil and copper repeating coil at 77 K and 300 K, respectively. Simulation and experimental results show that HTS and copper repeating coil can effectively enhance the space magnetic induction intensity, which has significant effect on improving the transmission efficiency and lengthening transmission distance. We found that the efficiency and the distance of wireless power transfer system with an HTS coil as repeater is much higher by using of copper coil as repeater.

  4. The cytoplasmic coiled-coil mediates cooperative gating temperature sensitivity in the voltage-gated H(+) channel Hv1.

    Science.gov (United States)

    Fujiwara, Yuichiro; Kurokawa, Tatsuki; Takeshita, Kohei; Kobayashi, Megumi; Okochi, Yoshifumi; Nakagawa, Atsushi; Okamura, Yasushi

    2012-05-08

    Hv1/VSOP is a dimeric voltage-gated H(+) channel in which the gating of one subunit is reportedly coupled to that of the other subunit within the dimer. The molecular basis for dimer formation and intersubunit coupling, however, remains unknown. Here we show that the carboxy terminus ends downstream of the S4 voltage-sensor helix twist in a dimer coiled-coil architecture, which mediates cooperative gating. We also show that the temperature-dependent activation of H(+) current through Hv1/VSOP is regulated by thermostability of the coiled-coil domain, and that this regulation is altered by mutation of the linker between S4 and the coiled-coil. Cooperative gating within the dimer is also dependent on the linker structure, which circular dichroism spectrum analysis suggests is α-helical. Our results indicate that the cytoplasmic coiled-coil strands form continuous α-helices with S4 and mediate cooperative gating to adjust the range of temperatures over which Hv1/VSOP operates.

  5. Stenting plus coiling: dangerous or helpful?; Stenting plus Coiling bei akut rupturierten intrakraniellen Aneurysmen

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, I.; Gizewski, E.; Doerfler, A.; Stolke, D.; Forsting, M. [Essen Univ. (Germany). Inst. fuer Radiologie und Neuroradiologie

    2005-09-01

    Purpose: the purpose of this study was to evaluate the procedural risk of treating acute ruptured aneurysms with a stentcoil combination. Material and methods: between August 2001 and January 2004 we treated nine acute subarachnoid hemorrhage (SAH) patients with a combination of stents and platinum coils. Results: six aneurysms were 100% eliminated; the residual three aneurysms had a 95% to 99% occlusion. A transient thrombosis in the stent in one patient could be recanalized by intravenous application of ReoPro {sup registered}. In another patient an occlusive vasospasm at the distal end of the stent was successfully treated with intraarterial Nimotop {sup registered}. Neurological complications occurred in none of the patients. Conclusion: in broad-based aneurysms which cannot be clipped or in which any neurosurgical treatment presents an unacceptably high risk (posterior circulation and paraophthalmic aneurysms), treatment using a combination of stent and platinum coils might be an option even in the acute phase of an SAH. Platelet aggregation can be treated with Aspirin registered and Plavix {sup registered} after placement of the first coil, vasospasms with intraarterial Nimotop {sup registered}, and acute stent thrombosis with GP IIa/IIIb-antagonists. (orig.)

  6. Design of transverse head gradient coils using a layer-sharing scheme

    Science.gov (United States)

    Wang, Yaohui; Liu, Feng; Zhou, Xiaorong; Crozier, Stuart

    2017-05-01

    In this paper, a new design for transverse asymmetric head gradient coils is proposed for Magnetic Resonance Imaging (MRI). Unlike the conventional coil designs where the x and y coils are placed onto separate radial layers, the new design has windings for both the x and y coils in each transverse coil layer. The coil performance using the new design was compared with the conventional coils with the same dimensions and constraints. The results showed that the new design can improve coil performance in terms of a lower inductance, lower resistance and a higher figure of merit.

  7. Controlled release of osteopontin and interleukin-10 from modified endovascular coil promote cerebral aneurysm healing.

    Science.gov (United States)

    Chen, Jingyi; Yang, Lijun; Chen, Yan; Zhang, Gengshen; Fan, Zheneng

    2016-01-15

    Cerebral aneurysm is a bulging of the artery inside the brain that results from a weakened or thin area of the artery wall. Ruptured cerebral aneurysm could lead to serious brain damage or even death, thus the proper treatment is essential. Compared with the conventional microsurgical clipping approach, the endovascular coiling treatment has many advantages, however, with a major disadvantage of high recurrence rate. One way to lower the recurrence rate, which has been tried since one decade ago, is to modify the coil to be bioactive and releasing biological molecules to stimulate tissue ingrowth and aneurysm healing. We have identified three candidates including osteopontin (OPN), IL-10 and matrix metallopeptidase 9 (MMP-9) from previous studies and generated platinum coils coated with these proteins in the carrier of poly-DL-lactic glycolic acid (PLGA). We were interested to know whether coils coated with OPN, IL-10 and MMP-9 were able to promote aneurysm healing and we have tested it in the rat carotid aneurysm model. We found that OPN and IL-10 coated coils had shown significant improvement in tissue ingrowth while MMP-9 coated coils failed to enhance tissue ingrowth compared with the control group. Our studies suggested the possible application of OPN and IL-10 coated coils in aneurysm treatment to overcome the recurrence.

  8. Predicting dihedral angle probability distributions for protein coil residues from primary sequence using neural networks

    DEFF Research Database (Denmark)

    Helles, Glennie; Fonseca, Rasmus

    2009-01-01

    Predicting the three-dimensional structure of a protein from its amino acid sequence is currently one of the most challenging problems in bioinformatics. The internal structure of helices and sheets is highly recurrent and help reduce the search space significantly. However, random coil segments...... make up nearly 40\\% of proteins, and they do not have any apparent recurrent patterns which complicates overall prediction accuracy of protein structure prediction methods. Luckily, previous work has indicated that coil segments are in fact not completely random in structure and flanking residues do...... seem to have a significant influence on the dihedral angles adopted by the individual amino acids in coil segments. In this work we attempt to predict a probability distribution of these dihedral angles based on the flanking residues. While attempts to predict dihedral angles of coil segments have been...

  9. Review of the ATLAS B0 model coil test program

    CERN Document Server

    Dolgetta, N; Acerbi, E; Berriaud, C; Boxman, H; Broggi, F; Cataneo, F; Daël, A; Delruelle, N; Dudarev, A; Foussat, A; Haug, F; ten Kate, H H J; Mayri, C; Paccalini, A; Pengo, R; Rivoltella, G; Sbrissa, E

    2004-01-01

    The ATLAS B0 model coil has been extensively tested, reproducing the operational conditions of the final ATLAS Barrel Toroid coils. Two test campaigns have taken place on B0, at the CERN facility where the individual BT coils are about to be tested. The first campaign aimed to test the cool-down, warm-up phases and to commission the coil up to its nominal current of 20.5 kA, reproducing Lorentz forces similar to the ones on the BT coil. The second campaign aimed to evaluate the margins above the nominal conditions. The B0 was tested up to 24 kA and specific tests were performed to assess: the coil temperature margin with respect to the design value, the performance of the double pancake internal joints, static and dynamic heat loads, behavior of the coil under quench conditions. The paper reviews the overall test program with emphasis on second campaign results not covered before. 10 Refs.

  10. SIMULATION OF STEEL COIL HEAT TRANSFER IN HPH FURNACE

    Institute of Scientific and Technical Information of China (English)

    M.Y. Gu; G. Chen; M.C. Zhang; X.C. Dai

    2005-01-01

    The mathematical model has been established for the simulation of steel coil's heat transfer during annealing thermal process in HPH (high performance hydrogen) furnace. The equivalent radial thermal conductivity is adopted by statistical analysis regression approach through the combination of a large quantity of production data collected in practice and theoretical analyses. The effect of the number of coils on circulating flow gas is considered for calculating the convection heat transfer coefficient. The temperature within the coil is predicted with the developed model during the annealing cycle including heating process ard cooling process. The good consistency between the predicted results and the experimental data has demonstrated that the mathematical model established and the parameters identified by this paper are scientifically feasible and the effective method of calculation for coil equivalent radial heat transfer coefficient and circulating gas flow has been identified successfully, which largely enhances the operability and feasibility of the mathematic model. This model provides a theoretical basis and an effective means to conduct studies on the impact that foresaid factors may imposed on the steel coil's temperature field, to analyze the stress within coils, to realize online control and optimal production and to increase facility output by increasing heating and cooling rates of coils without producing higher thermal stress.

  11. The noise factor of receiver coil matching networks in MRI.

    Science.gov (United States)

    Cao, Xueming; Fischer, Elmar; Gruschke, Oliver; Korvink, Jan G; Hennig, Jürgen; Maunder, Adam M; De Zanche, Nicola; Zaitsev, Maxim

    2017-04-01

    In typical MRI applications the dominant noise sources in the received signal are the sample, the coil loop and the preamplifier. We hypothesize that in some cases (e.g. for very small receiver coils) the matching network noise has to be considered explicitly. Considering the difficulties of direct experimental determinations of the noise factor of matching networks with sufficient accuracy, it is helpful to estimate the noise factor by calculation. A useful formula of the coil matching network is obtained by separating commonly used coil matching network into different stages and calculating their noise factor analytically by a combination of the noise from these stages. A useful formula of the coil matching network is obtained. ADS simulations are performed to verify the theoretical predictions. Thereafter carefully-designed proof-of-concept phantom experiments are carried out to qualitatively confirm the predicted SNR behavior. The matching network noise behavior is further theoretically investigated for a variety of scenarios. It is found that in practice the coil matching network noise can be improved by adjusting the coil open port resonant frequency.

  12. MANUFACTURING OF MAGNETIC PROBE COILS FOR DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    BOZEK,A.S; STRAIT,E.J

    2003-10-01

    OAK-B135 The magnetic diagnostics program at DIII-D adds to its in-vessel installations of induction-type loops and coils almost every year. The current design of toroidal and poloidal magnetic field coils (45-50 kHz, N {center_dot} A = 0.06 m{sup 2}) has been in existence since 1987. Many coils were installed in DIII-D during that year and are still operating and reliable today. The high reliability of the coils is owing to the use of a continuous length of mineral-insulated cable, eliminating any electrical connections inside the vacuum vessel. The geometry of the probes was designed to achieve a bandwidth of 50 kHz, despite the conducting shell formed by the stainless steel sheath of the mineral-insulated cable. The bandwidth is sensitive to the details of the cable dimensions and winding technique, and care must be taken in the fabrication in order to maintain this specification. With possible future magnetic diagnostics installations IN ITER and other long-pulse machines requiring large numbers of coils and/or multiple layers per coil, the manufacturing scale-up, quality control, and the development of layered coils should all be investigated in addition to the obvious issues such as irradiation effects.

  13. Endothelial cell proliferation in swine experimental aneurysm after coil embolization.

    Directory of Open Access Journals (Sweden)

    Yumiko Mitome-Mishima

    Full Text Available After coil embolization, recanalization in cerebral aneurysms adversely influences long-term prognosis. Proliferation of endothelial cells on the coil surface may reduce the incidence of recanalization and further improve outcomes after coil embolization. We aimed to map the expression of proliferating tissue over the aneurysmal orifice and define the temporal profile of tissue growth in a swine experimental aneurysm model. We compared the outcomes after spontaneous thrombosis with those of coil embolization using histological and morphological techniques. In aneurysms that we not coiled, spontaneous thrombosis was observed, and weak, easily detachable proliferating tissue was evident in the aneurysmal neck. In contrast, in the coil embolization group, histological analysis showed endothelial-like cells lining the aneurysmal opening. Moreover, immunohistochemical and morphological analysis suggested that these cells were immature endothelial cells. Our results indicated the existence of endothelial cell proliferation 1 week after coil embolization and showed immature endothelial cells in septal tissue between the systemic circulation and the aneurysm. These findings suggest that endothelial cells are lead to and proliferate in the former aneurysmal orifice. This is the first examination to evaluate the temporal change of proliferating tissue in a swine experimental aneurysm model.

  14. Fetal MRI on a multi-element digital coil platform

    Energy Technology Data Exchange (ETDEWEB)

    Serai, Suraj D.; Merrow, Arnold C.; Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, 3333 Burnett Ave., MLC 5031, Cincinnati, OH (United States)

    2013-09-15

    Fetal MRI has an increasing list of indications and is most commonly employed when anomalies detected by prenatal ultrasonography require further characterization. This may occur when sonography is technically challenging or where specific MRI findings will determine pre- and postnatal management, including critical in utero and/or peripartum interventions. In these circumstances, there are high expectations for MRI to sort out complex diagnostic dilemmas through exquisite anatomical imaging that fetal surgeons and obstetricians can comprehend and relay to their patients. These expectations, in light of evolving clinical innovations, continue to drive advances in fetal imaging. Increasing signal-to-noise ratio (SNR) is fundamental to improving MR image quality, and proper coil selection is a key component of this pursuit. Since the introduction of parallel imaging techniques, the numbers of elements in phased-array coils have been continuously increased to achieve high SNR and shorter scan times. With the invention of a digital coil platform, it is now possible to connect combinations of multiple coil elements to enhance SNR beyond the capabilities of the adult eight-channel torso-coil routinely used in fetal imaging. This paper describes the application of multi-element radiofrequency coils on a digital broadband imaging platform with unique coil combinations to perform dedicated fetal MRI. (orig.)

  15. MEMS switch integrated radio frequency coils and arrays for magnetic resonance imaging

    Science.gov (United States)

    Bulumulla, S. B.; Park, K. J.; Fiveland, E.; Iannotti, J.; Robb, F.

    2017-02-01

    Surface coils are widely used in magnetic resonance imaging and spectroscopy. While smaller diameter coils produce higher signal to noise ratio (SNR) closer to the coil, imaging larger fields of view or greater distance into the sample requires a larger overall size array or, in the case of a channel count limited system, larger diameter coils. In this work, we consider reconfiguring the geometry of coils and coil arrays such that the same coil or coil array may be used in multiple field of view imaging. A custom designed microelectromechanical systems switch, compatible with magnetic resonance imaging, is used to switch in/out conductive sections and components to reconfigure coils. The switch does not degrade the SNR and can be opened/closed in 10 μ s, leading to rapid reconfiguration. Results from a single coil, configurable between small/large configurations, and a two-coil phased array, configurable between spine/torso modes, are presented.

  16. Improvement of Prediction Method for Strip Coiling Temperature

    Institute of Scientific and Technical Information of China (English)

    YU Qing-bo; WANG Zhao-dong; WANG Zhe-ying; LIU Xiang-hua; WANG Guo-dong

    2003-01-01

    In order to improve the control precision of strip coiling temperature for hot strip mill, the BP neural network was combined with mathematical model to calculate convective heat-transfer coefficient of laminar flow cooling. The off-line calculated results indicate that the standard deviation of coiling temperature prediction is reduced by 22.84 % with the convective heat-transfer coefficient calculated by BP neural network. The prospects of this method for on-line application are bright. This method is more helpful to increasing the control precision of coiling temperature for hot strip steel.

  17. Design and manufacturing of a Wendelstein 7-X demonstration coil

    Energy Technology Data Exchange (ETDEWEB)

    Kronhardt, H. [Preussag Noell GmbH, Wuerzburg (Germany); Dormicchi, O. [Ansalto Energia, Genoa (Italy); Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1998-07-01

    The large Stellarator experiment Wendelstein 7-X is currently being constructed at the Max-Planck-Institute for Plasma physics (IPP). The magnet system consists of 50 non-planar and 20 planar superconducting coils. A full-size non-planar DEMO coil was built under industrial conditions, to be tested in the background field of the EU-LCT coil at the Forschungszentrum Karlsruhe (FZK). This paper reports the final manufacturing results and data from the warm acceptance test, as well as cryogenic data from strandmeasurements. (author)

  18. Magnetic mirror structure for testing shell-type quadrupole coils

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, N.; Turrioni, D.; /Fermilab

    2009-10-01

    This paper presents magnetic and mechanical designs and analyses of the quadrupole mirror structure to test single shell-type quadrupole coils. Several quadrupole coils made of different Nb{sub 3}Sn strands, cable insulation and pole materials were tested using this structure at 4.5 and 1.9 K. The coils were instrumented with voltage taps, spot heaters, temperature sensors and strain gauges to study their mechanical and thermal properties and quench performance. The results of the quadrupole mirror model assembly and test are reported and discussed.

  19. Magnetic mirror structure for testing shell-type quadrupole coils

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, N.; Barzi, E.; Bossert, R.; Chlachidze, G.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Nobrega, F.; Novitski, I.; Tartaglia, N.; Turrioni, D.; /Fermilab

    2009-10-01

    This paper presents magnetic and mechanical designs and analyses of the quadrupole mirror structure to test single shell-type quadrupole coils. Several quadrupole coils made of different Nb{sub 3}Sn strands, cable insulation and pole materials were tested using this structure at 4.5 and 1.9 K. The coils were instrumented with voltage taps, spot heaters, temperature sensors and strain gauges to study their mechanical and thermal properties and quench performance. The results of the quadrupole mirror model assembly and test are reported and discussed.

  20. Parametric design of tri-axial nested Helmholtz coils.

    Science.gov (United States)

    Abbott, Jake J

    2015-05-01

    This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

  1. A transition from strong right-handed to canonical left-handed supercoiling in a conserved coiled-coil segment of trimeric autotransporter adhesins.

    Science.gov (United States)

    Alvarez, Birte Hernandez; Gruber, Markus; Ursinus, Astrid; Dunin-Horkawicz, Stanislaw; Lupas, Andrei N; Zeth, Kornelius

    2010-05-01

    Trimeric autotransporter adhesins (TAAs) represent an important class of pathogenicity factors in proteobacteria. Their defining feature is a conserved membrane anchor, which forms a 12-stranded beta-barrel through the outer membrane. The proteins are translocated through the pore of this barrel and, once export is complete, the pore is occluded by a three-stranded coiled coil with canonical heptad (7/2) sequence periodicity. In many TAAs this coiled coil is extended by a segment of varying length, which has pentadecad (15/4) periodicity. We used X-ray crystallography and biochemical methods to analyze the transition between these two periodicities in the coiled-coil stalk of the Yersinia adhesin YadA. Our results show how the strong right-handed supercoil of the 15/4-periodic part locally undergoes further over-winding to 19/5, before switching at a fairly constant rate over 14 residues to the canonical left-handed supercoil of the 7/2-periodic part. The transition region contains two YxD motifs, which are characteristic for right-handed coiled-coil segments of TAAs. This novel coiled-coil motif forms a defined network of inter- and intrahelical hydrogen bonds, thus serving as a structural determinant. Supercoil fluctuations have hitherto been described in coiled coils whose main sequence periodicity is disrupted locally by discontinuities. Here we present the first detailed analysis of two fundamentally different coiled-coil periodicities being accommodated in the same structure.

  2. The Role of Filtration in Maintaining Clean Heat Exchanger Coils

    Energy Technology Data Exchange (ETDEWEB)

    Li Yang; James E. Braun; Eckhard A. Groll

    2004-06-30

    The main purpose of the study was to investigate the role of filtration in maintaining clean heat exchanger coils and overall performance. Combinations of 6 different levels of filtration (MERV 14, 11, 8, 6, 4, and no filter) and 4 different coils (an eight-row lanced-fin coil, HX8L), (an eight-row wavy-fin coil, HX8W), (a four-row lanced-fin coil, HX4L) and (a two-row lanced-fin coil, HX2L) were tested at 4 different air velocities (1.52, 2.03, 2.54,3.05 m/s (300, 400, 500, 600 ft/min)). The fouled conditions were obtained after injection of 600 grams of ASHRAE standard dust upstream of the filter/coil combination. This magnitude of dust is representative of a year of normal operation for an air conditioning system. The air-side pressure drops of the coils and filters and air-side heat transfer coefficients of the coils were determined from the measurements under the clean and fouled conditions. Depending upon the filter and coil test, the coil pressure drops increased in the range of 6%-30% for an air velocity at 2.54 m/s (500 ft/min). The impact was significantly greater for tests performed without a filter. The largest relative effect of fouling on pressure drop occurs for coils with fewer rows and having lanced fins. Coils with a greater number of rows can hold more dust so that a fixed amount of dust has a relatively smaller impact. The impact of fouling on air-side heat transfer coefficients was found to be relatively small. In some cases, heat transfer was actually enhanced due to additional turbulence caused by the presence of dust. The experimental results for pressure drops and heat transfer coefficients were correlated and the correlations were implemented within computer models of prototypical rooftop air conditioners and used to evaluate the impact of fouling on cooling capacity and EER. The equipment cooling capacity is reduced with fouling primarily because of a decrease in air flow due to the increase pressure drop rather than due to changes in h

  3. Balance between Coiled-Coil Stability and Dynamics Regulates Activity of BvgS Sensor Kinase in Bordetella

    Directory of Open Access Journals (Sweden)

    E. Lesne

    2016-03-01

    Full Text Available The two-component system BvgAS controls the expression of the virulence regulon of Bordetella pertussis. BvgS is a prototype of bacterial sensor kinases with extracytoplasmic Venus flytrap perception domains. Following its transmembrane segment, BvgS harbors a cytoplasmic Per-Arnt-Sim (PAS domain and then a predicted 2-helix coiled coil that precede the dimerization-histidine-phosphotransfer domain of the kinase. BvgS homologs have a similar domain organization, or they harbor only a predicted coiled coil between the transmembrane and the dimerization-histidine-phosphotransfer domains. Here, we show that the 2-helix coiled coil of BvgS regulates the enzymatic activity in a mechanical manner. Its marginally stable hydrophobic interface enables a switch between a state of great rotational dynamics in the kinase mode and a more rigid conformation in the phosphatase mode in response to signal perception by the periplasmic domains. We further show that the activity of BvgS is controlled in the same manner if its PAS domain is replaced with the natural α-helical sequences of PAS-less homologs. Clamshell motions of the Venus flytrap domains trigger the shift of the coiled coil’s dynamics. Thus, we have uncovered a general mechanism of regulation for the BvgS family of Venus flytrap-containing two-component sensor kinases.

  4. The significant impact of framing coils on long-term outcomes in endovascular coiling for intracranial aneurysms: how to select an appropriate framing coil.

    Science.gov (United States)

    Ishida, Wataru; Sato, Masayuki; Amano, Tatsuo; Matsumaru, Yuji

    2016-09-01

    OBJECTIVE The importance of a framing coil (FC)-the first coil inserted into an aneurysm during endovascular coiling, also called a lead coil or a first coil-is recognized, but its impact on long-term outcomes, including recanalization and retreatment, is not well established. The purposes of this study were to test the hypothesis that the FC is a significant factor for aneurysmal recurrence and to provide some insights on appropriate FC selection. METHODS The authors retrospectively reviewed endovascular coiling for 280 unruptured intracranial aneurysms and gathered data on age, sex, aneurysm location, aneurysm morphology, maximal size, neck width, adjunctive techniques, recanalization, retreatment, follow-up periods, total volume packing density (VPD), volume packing density of the FC, and framing coil percentage (FCP; the percentage of FC volume in total coil volume) to clarify the associated factors for aneurysmal recurrence. RESULTS Of 236 aneurysms included in this study, 33 (14.0%) had recanalization, and 18 (7.6%) needed retreatment during a mean follow-up period of 37.7 ± 16.1 months. In multivariate analysis, aneurysm size (odds ratio [OR] = 1.29, p < 0.001), FCP < 32% (OR 3.54, p = 0.009), and VPD < 25% (OR 2.96, p = 0.015) were significantly associated with recanalization, while aneurysm size (OR 1.25, p < 0.001) and FCP < 32% (OR 6.91, p = 0.017) were significant predictors of retreatment. VPD as a continuous value or VPD with any cutoff value could not predict retreatment with statistical significance in multivariate analysis. CONCLUSIONS FCP, which is equal to the FC volume as a percentage of the total coil volume and is unaffected by the morphology of the aneurysm or the measurement error in aneurysm length, width, or height, is a novel predictor of recanalization and retreatment and is more significantly predictive of retreatment than VPD. To select FCs large enough to meet the condition of FCP ≥ 32% is a potential relevant factor for better

  5. Formation of current coils in geodynamo simulations.

    Science.gov (United States)

    Kageyama, Akira; Miyagoshi, Takehiro; Sato, Tetsuya

    2008-08-28

    Computer simulations have been playing an important role in the development of our understanding of the geodynamo, but direct numerical simulation of the geodynamo with a realistic parameter regime is still beyond the power of today's supercomputers. Difficulties in simulating the geodynamo arise from the extreme conditions of the core, which are characterized by very large or very small values of the non-dimensional parameters of the system. Among them, the Ekman number, E, has been adopted as a barometer of the distance of simulations from real core conditions, in which E is of the order of 10(-15). Following the initial computer simulations of the geodynamo, the Ekman number achieved has been steadily decreasing, with recent geodynamo simulations performed with E of the order of 10(-6). Here we present a geodynamo simulation with an Ekman number of the order of 10(-7)-the highest-resolution simulation yet achieved, making use of 4,096 processors of the Earth Simulator. We have found that both the convection flow and magnetic field structures are qualitatively different from those found in larger-Ekman-number dynamos. The convection takes the form of sheet plumes or radial sheet jets, rather than the columnar cell structures that are usually found. We have found that this sheet plume convection is an effective dynamo and the generated current is organized as a set of coils in the shape of helical springs or at times as a torus.

  6. The Search-Coil Magnetometer for MMS

    Science.gov (United States)

    Le Contel, O.; Leroy, P.; Roux, A.; Coillot, C.; Alison, D.; Bouabdellah, A.; Mirioni, L.; Meslier, L.; Galic, A.; Vassal, M. C.; Torbert, R. B.; Needell, J.; Rau, D.; Dors, I.; Ergun, R. E.; Westfall, J.; Summers, D.; Wallace, J.; Magnes, W.; Valavanoglou, A.; Olsson, G.; Chutter, M.; Macri, J.; Myers, S.; Turco, S.; Nolin, J.; Bodet, D.; Rowe, K.; Tanguy, M.; de la Porte, B.

    2016-03-01

    The tri-axial search-coil magnetometer (SCM) belongs to the FIELDS instrumentation suite on the Magnetospheric Multiscale (MMS) mission (Torbert et al. in Space Sci. Rev. (2014), this issue). It provides the three magnetic components of the waves from 1 Hz to 6 kHz in particular in the key regions of the Earth's magnetosphere namely the subsolar region and the magnetotail. Magnetospheric plasmas being collisionless, such a measurement is crucial as the electromagnetic waves are thought to provide a way to ensure the conversion from magnetic to thermal and kinetic energies allowing local or global reconfigurations of the Earth's magnetic field. The analog waveforms provided by the SCM are digitized and processed inside the digital signal processor (DSP), within the Central Electronics Box (CEB), together with the electric field data provided by the spin-plane double probe (SDP) and the axial double probe (ADP). On-board calibration signal provided by DSP allows the verification of the SCM transfer function once per orbit. Magnetic waveforms and on-board spectra computed by DSP are available at different time resolution depending on the selected mode. The SCM design is described in details as well as the different steps of the ground and in-flight calibrations.

  7. Coil-Type Asymmetric Supercapacitor Electrical Cables.

    Science.gov (United States)

    Yu, Zenan; Moore, Julian; Calderon, Jean; Zhai, Lei; Thomas, Jayan

    2015-10-21

    Cable-shaped supercapacitors (SCs) have recently aroused significant attention due to their attractive properties such as small size, lightweight, and bendability. Current cable-shaped SCs have symmetric device configuration. However, if an asymmetric design is used in cable-shaped supercapacitors, they would become more attractive due to broader cell operation voltages, which results in higher energy densities. Here, a novel coil-type asymmetric supercapacitor electrical cable (CASEC) is reported with enhanced cell operation voltage and extraordinary mechanical-electrochemical stability. The CASECs show excellent charge-discharge profiles, extraordinary rate capability (95.4%), high energy density (0.85 mWh cm(-3)), remarkable flexibility and bendability, and superior bending cycle stability (≈93.0% after 4000 cycles at different bending states). In addition, the CASECs not only exhibit the capability to store energy but also to transmit electricity simultaneously and independently. The integrated electrical conduction and storage capability of CASECS offer many potential applications in solar energy storage and electronic gadgets. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. ITER coils insulation R and D program

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, R.F.; Sugimoto, M.; Osaki, O.; Fujioka, T.; Korsunsky, V.; Reed, R.P.; Katheder, H.; Broadbent, A.

    1995-12-31

    The ITER coil insulation systems are required for operating voltages up to 10 KV and to support shear and normal compression loads through the winding pack. Manufacturing considerations and nuclear radiation resistance also influence the choice of suitable systems. A screening program of candidate systems is being conducted in stages. The first stage is reported in this paper. Present R and D data based on small samples indicate a static shear strength of about 85 MPa for a glass or alumina and epoxy resin vacuum pressure impregnation system and 50 MPa for a pre-impregnated glass/epoxy resin system with polyimide interleaved at a temperature of 4K. The preliminary irradiation results show that coating the steel surface with inorganic materials such as Al{sub 2}O{sub 3} or ZrO{sub 2}/8 Y{sub 2}O{sub 3} is beneficial in increasing the radiation resistance as far as shear strength is concerned. In addition Tetrafunctional epoxy (TGDM) systems appear to be more radiation resistant than Diglycidyl Ether of Bisphenol-A (DGEBA) systems. Further R and D work will focus on prototypical samples to continue evaluation of the performance of the insulation systems.

  9. Revisiting Coiled Flocculator Performance for Particle Aggregation.

    Science.gov (United States)

    2017-09-08

    This work summarizes recent studies evaluating the torsion and curvature parameters in the flocculation efficiency using a hydraulic plug-flow flocculator named as Flocs Generator Reactor (FGR). Colloidal Fe(OH)3 and coal particles were used as suspension models and a cationic polyacrylamide was used for the flocculation. The effectiveness of the aggregation process (in the distinct curvature and torsion parameters and hydrodynamic conditions) was evaluated by the settling rate of the Fe(OH)3 flocs and flocs size by photographic analysis. Due to curvature, a secondary flow is induced and the profiles of the flow quantities differ from those for a straight pipe. Results showed that the difference in the flocculator design influences the Fe(OH)3 flocs size and settling rates, reaching values about 13 and 4 mh-1, for the coiled and straight pipes respectively. Coal flocs generation also showed to be dependent on the flocculator design and shear rate. Results showed that turbulent kinetic energy increases due to curvature when the torsion parameter is kept constant (pitch close to zero) enhancing the flocs formation.

  10. Implementation of a planar coil of wires as a sinus-galvanometer. Analysis of the coil magnetic field

    CERN Document Server

    Stoyanov, Dimitar G

    2010-01-01

    The paper presents a theoretical analysis on the interaction between the Earth's magnetic field of a compass needle and the magnetic field of a straight infinite current-carrying wire. Implementation of a planar horizontal coil of wires has been shown as a sinus galvanometer. The magnetic field over the planar coil of wires has been examined by experiment. The coil could be used as a model for straight infinite current wire in demonstration set-ups or could be given as an assignment in Physics laboratory workshops.

  11. Implementation of a planar coil of wires as a sinus-galvanometer. Analysis of the coil magnetic field

    OpenAIRE

    Stoyanov, Dimitar G.

    2010-01-01

    The paper presents a theoretical analysis on the interaction between the Earth's magnetic field of a compass needle and the magnetic field of a straight infinite current-carrying wire. Implementation of a planar horizontal coil of wires has been shown as a sinus galvanometer. The magnetic field over the planar coil of wires has been examined by experiment. The coil could be used as a model for straight infinite current wire in demonstration set-ups or could be given as an assignment in Physic...

  12. Novel Coil Winding Method to Realize Pot Heated Evenly

    Institute of Scientific and Technical Information of China (English)

    Mao-Yan Wang; Hai-Long Li; Meng Zhang; Zhi-Tao Xu; Cui-Lin Zhong; Jun Xu

    2015-01-01

    To solve the problem about the inhomogeneous thermal effect of pot heated by coils along the circumference, a novel coil winding method is proposed and compared with the general winding method in the paper. First, based on the Biot-Savart law and Ampere’s rule, the magnetic induction generated by a straight current carrying conductor and a current loop is discussed, respectively. Then the novel coil winding method is developed by adjusting the location of inhomogeneous joints. The joints are periodically scattered along the circumferential direction and symmetrically designed around the central axis. Numerical results show that the quite non-uniform temperature in the base of pot at the circular direction is effectively improved by using the proposed winding method. The potential danger produced by high temperature at some region of coils plate is minimized. It is energy-efficient and safe for residential appliances.

  13. High-quality Critical Heat Flux in Horizontally Coiled Tubes

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    An investigation on the high-quality dryout in two electrically heated coiled tubes with horizontally helix axes is reported.The temperature profiles both along the tube and around the circumference are measured.and it is found that the temperature profiles around the circumference are not identical for the corss-sections at different parts of the coil.The “local condition hypothesis” seems applicable under present conditions,and the critical heat flux qcr decreases with increasing critical quality xcr.The CHF increases as mass velocity and ratio of tube diameter to coil diameter(d/D) increases,and it seems not to be affected hby the system pressure.The CHF is larger with coils than that with straight tubes,and the difference increases with increasing mass velocity and d/D.

  14. Characterization of coiled SMA actuators for humanoid robot

    Science.gov (United States)

    Potnuru, Akshay; Tadesse, Yonas

    2017-04-01

    In this paper, we present modeling and characterization of coiled SMA spring actuators that are fabricated by coiling cylindrical SMA wires on to a threaded screw mandrel and applying heat treatment. Here, we evaluate a theoretical model that describes the actuation behavior of SMA coiled springs based on the constitutive model of SMA. We have experimentally verified the developed theoretical model and analyzed various parameters with respect to temperature change during actuation. The model was coded in Simulink® and the effects of various parameters with respect to temperature change were investigated. Simulations were compared with experiments and good agreement was obtained. We also show, how the high tension winding of SMA on the mandrel help in better performance and understanding of the fabricated coiled SMAs.

  15. Coiled Brine Recovery Assembly (CoBRA) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Coiled Brine Recovery Assembly (CoBRA) project will result in a proof-of-concept demonstration for a lightweight, compact, affordable, regenerable and disposable...

  16. Critical Current Measurements in Commercial Tapes, Coils, and Magnets.

    Science.gov (United States)

    Gubser, D. U.; Soulen, R. J., Jr.; Fuller-Mora, W. W.; Francavilla, T. L.

    1996-03-01

    We have measured a number of tapes, coils, and magnets produced by commercial vendors and determined their properties as functions of magnetic field and temperature. The tapes were measured at the National High Magnetic Field Laboratory in magnetic fields to 20 tesla and at temperatures of 4.2 K, 27 K, 65 K, and 77 K. For the tapes we report critical currents and current-voltage characteristics. Six inch diameter coils were measured at NRL in zero magnetic field. Critical currents, current-voltage characteristics, and reliability studies are reported for the coils. Larger 10 inch diameter coils, which are to be used in a 200 hp superconducting motor, were also measured and results will be presented. The talk will also review the status of the most recent tests of the superconducting motor.

  17. Foldable micro coils for a transponder system measuring intraocular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ullerich, S.; Schnakenberg, U. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1; Mokwa, W. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1]|[Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany); Boegel, G. vom [Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany)

    2001-07-01

    A foldable transponder system consisting of a chip and a micro coil for measuring intraocular pressure continuously is presented. The system will be integrated in the haptic of a soft artificial intraocular lens. Calculations of planar micro coils with 6 mm and 10.3 mm in diameter show the limits for planar coils with an outer diameter of 6 mm. For the realisation of the transponder system a 20 {mu}m thick coil with an outer diameter of 10.3 mm, an inner diameter of 7.7 mm, 16 turns and a gap of 20 {mu}m between the windings was selected. Measurements show a good agreement between calculated and measured values. Wireless pressure measurements were carried out showing a linear behaviour of the output signal with respect to the applied pressure. (orig.)

  18. 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.

  19. Control of critical coupling in a coiled coaxial cable resonator.

    Science.gov (United States)

    Huang, Jie; Wei, Tao; Wang, Tao; Fan, Jun; Xiao, Hai

    2014-05-01

    This paper reports a coiled coaxial cable resonator fabricated by cutting a slot in a spring-like coiled coaxial cable to produce a periodic perturbation. Electromagnetic coupling between two neighboring slots was observed. By manipulating the number of slots, critical coupling of the coiled coaxial cable resonator can be well controlled. An ultrahigh signal-to-noise ratio (over 50 dB) at the resonant frequency band was experimentally achieved from a coiled coaxial cable resonator with 38 turns. A theoretic model is developed to understand the device physics. The proposed device can be potentially used as a high quality and flexibly designed band-stop filter or a sensor in structural health monitoring.

  20. Experiment of low resistance joints for the ITER correction coil.

    Science.gov (United States)

    Liu, Huajun; Wu, Yu; Wu, Weiyue; Liu, Bo; Shi, Yi; Guo, Shuai

    2013-01-01

    A test method was designed and performed to measure joint resistance of the ITER correction coil (CC) in liquid helium (LHe) temperature. A 10 kA superconducting transformer was manufactured to provide the joints current. The transformer consisted of two concentric layer-wound superconducting solenoids. NbTi superconducting wire was wound in the primary coil and the ITER CC conductor was wound in the secondary coil. The primary and the secondary coils were both immersed in liquid helium of a 300 mm useful bore diameter cryostat. Two ITER CC joints were assembled in the secondary loop and tested. The current of the secondary loop was ramped to 9 kA in several steps. The two joint resistances were measured to be 1.2 nΩ and 1.65 nΩ, respectively.

  1. Rapid mixing of viscous liquids by electrical coiling

    Science.gov (United States)

    Kong, Tiantian; Li, Jingmei; Liu, Zhou; Zhou, Zhuolong; Ng, Peter Hon Yu; Wang, Liqiu; Shum, Ho Cheung

    2016-02-01

    The control for the processing of precursor liquids determines whether the properties and functions of the final material product can be engineered. An inherent challenge of processing viscous liquids arises from their large resistance to deform. Here, we report on the discovery of an electric approach that can significantly contribute to address this challenge. The applied electric force can induce a straight viscous jet to coil, and the resulting coiling characteristics are governed by the electric stress. We demonstrate the promising use of electrical coiling in the rapid and efficient mixing of viscous liquids. Remarkably, the degree of mixing can be precisely adjusted by tuning the applied electric stress. Our approach of controlling the coiling electrically has important implications on applications such as dispensing and printing of resins, printing patterned surfaces and scaffolds, processing of food and generating non-woven fabrics.

  2. Test data from the US-Demonstration Poloidal Coil experiment

    Energy Technology Data Exchange (ETDEWEB)

    Painter, T.A.; Steeves, M.M.; Takayasu, M.; Gung, C.; Hoenig, M.O. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center; Tsuji, H.; Ando, T.; Hiyama, T.; Takahashi, Y.; Nishi, M.; Yoshida, K.; Okuno, K.; Nakajima, H.; Kato, T.; Sugimoto, M.; Isono, T.; Kawano, K.; Koizumi, N.; Osikiri, M.; Hanawa, H.; Ouchi, H.; Ono, M.; Ishida, H.; Hiue, H.; Yoshida, J.; Kamiyauchi, Y.; Ouchi, T.; Tajiri, F.; Kon, Y.; Shimizu, H.; Matsuzaki, Y.; Oomori, S.; Tani, T.; Oomori, K.; Terakado, T.; Yagyu, J.; Oomori, H. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Superconducting Magnet Lab.

    1992-01-01

    The US Demonstration Poloidal Field Coil (US-DPC) experiment took place successfully at the Japan Atomic Energy Research Institute (JAERI) in late 1990. The 8 MJ niobium-tin coil was leak tight; it performed very well in DC tests; it performed well in AC tests, achieving approximately 70% of its design goal. An unexpected ramp-rate barrier at high currents was identified. The barrier could not be explored in the regime of higher fields and slower ramp rates due to limitations of the background-field coils. This document presents the results of the experiment with as little editing as possible. The coil, conductor, and operating conditions are given. The intent is to present data in a form that can be used by magnet analysts and designers.

  3. Convective heat transfer enhancement inside tubes using inserted helical coils

    Science.gov (United States)

    Ali, R. K.; Sharafeldeen, M. A.; Berbish, N. S.; Moawed, M. A.

    2016-01-01

    Convective heat transfer was experimentally investigated in tubes with helical coils inserts in turbulent flow regime within Reynolds number range of 14400 ≤ Re ≤ 42900. The present work aims to extend the experimental data available on wire coil inserts to cover wire diameter ratio from 0.044 to 0.133 and coil pitch ratio from 1 to 5. Uniform heat flux was applied to the external surface of the tube and air was selected as fluid. The effects of Reynolds number and wire diameter and coil pitch ratios on the Nusselt number and friction factor were studied. The enhancement efficiency and performance criteria ranges are of (46.9-82.6%) and (100.1-128%) within the investigated range of the different parameters, respectively. Correlations are obtained for the average Nusselt number and friction factor utilizing the present measurements within the investigated range of geometrical parameters and Re.

  4. 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.

  5. Experimental evaluation of helically coiled tube flocculators for ...

    African Journals Online (AJOL)

    Experimental evaluation of helically coiled tube flocculators for turbidity removal ... clarification system, while varying hydraulic and geometrical parameters in HCTs. ... of baffled tank processing times) were observed for high efficiency process ...

  6. A hybrid optimization method for biplanar transverse gradient coil design

    Energy Technology Data Exchange (ETDEWEB)

    Qi Feng [Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Tang Xin [Beijing Key Laboratory of Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Jin Zhe [Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Jiang Zhongde [Beijing Key Laboratory of Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Shen Yifei [Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Meng Bin [Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China); Zu Donglin [Beijing Key Laboratory of Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Wang Weimin [Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

    2007-05-07

    The optimization of transverse gradient coils is one of the fundamental problems in designing magnetic resonance imaging gradient systems. A new approach is presented in this paper to optimize the transverse gradient coils' performance. First, in the traditional spherical harmonic target field method, high order coefficients, which are commonly ignored, are used in the first stage of the optimization process to give better homogeneity. Then, some cosine terms are introduced into the series expansion of stream function. These new terms provide simulated annealing optimization with new freedoms. Comparison between the traditional method and the optimized method shows that the inhomogeneity in the region of interest can be reduced from 5.03% to 1.39%, the coil efficiency increased from 3.83 to 6.31 mT m{sup -1} A{sup -1} and the minimum distance of these discrete coils raised from 1.54 to 3.16 mm.

  7. NSTX-U Digital Coil Protection System Software Detailed Design

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-06-01

    The National Spherical Torus Experiment (NSTX) currently uses a collection of analog signal processing solutions for coil protection. Part of the NSTX Upgrade (NSTX-U) entails replacing these analog systems with a software solution running on a conventional computing platform. The new Digital Coil Protection System (DCPS) will replace the old systems entirely, while also providing an extensible framework that allows adding new functionality as desired.

  8. Development and testing of the cooling coil cleaning end effector

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.I.; Mullen, O.D.; Powell, M.R.; Daly, D.S.; Engel, D.W.

    1997-09-30

    The Retrieval Process Development and Enhancement (KPD{ampersand}E) program has developed and tested an end effector to support the waste retrieval mission at the Idaho National Engineering and Environmental Laboratory (INEEL). The end effector was developed specifically to remove a sticky waste material from the cooling coils in the High Level Liquid Waste (HLLW) tank, and to vacuum up a sediment layer that has settled beneath the cooling coils. An extensive testing program was conducted in the hydraulic test bed (HTB) at the Pacific Northwest National Laboratory (PNNL) to evaluate the performance of the end effector under simulated in-tank conditions. A mock up of the cooling coils was installed in the test bed tank, and simulated waste materials were included to represent the sticky waste on the tubes and the particulate waste settled beneath them. The testing program focused on assessing long-duration mining strategies for cleaning the cooling coils and removing the particulate waste forms. The report describes the results of the end effector testing program at PNNL. Section 2 describes the physical characteristics of the HLLW tanks, including the layout of the cooling coils, and it also describes what is known of the waste forms in the tanks. Section 3 describes the cleaning and retrieval strategy that was used in developing the end effector design. Section 4 describes the cooling coil mockup in the hydraulic test bed. Section 5 discusses the rationale used in selecting the simulants for the tarry waste and particulate waste forms. Section 6 describes the tests that were performed to evaluate cleaning of the cooling coils and retrieval of the particulate simulant. Section 7 summarizes the cleaning and retrieval tests, assesses the relative importance of cleaning the cooling coils and retrieving the particulate waste, and suggests modifications that would simplify the end effector design.

  9. Treatment of pulmonary arteriovenous malformation using platinum coils: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Deuk; Kim, Jeung Sook; Lim, Chang Young [College of Medicine, Pochon CHA University, Pochon (China)

    2005-07-15

    Pulmonary arteriovenous malformation (PAVM) is an abnormal direct communication between the pulmonary arteries and veins without any capillary network. The patients may be completely asymptomatic or may they develop serious complications including hemoptysis and brain abscess. We present here a case of incidentally found PAVM in a 33-year-old male who underwent embolization using platinum coils. Coil embolization is a safe, highly effective procedure that should be considered more often for the treatment of PAVM.

  10. High-Q Antennas with built-in coils

    DEFF Research Database (Denmark)

    Bahramzy, Pevand; Svendsen, Simon; Pedersen, Gert Frølund

    2014-01-01

    Efficiency and isolation, at low frequencies (700 MHz), are two of the most important metrics for successful multicommunication implementation. This paper presents an antenna concept, that exhibits a very high isolation between high-Q Tx and Rx antennas at 700 MHz. Furthermore, it is shown how...... coils can be integrating into the antenna structure for obtaining better efficiency. It is shown that by integrated coils into the antenna structure, the efficiency can be improved by 2dB for each antenna....

  11. Support system for the W7-X coil assembly

    Energy Technology Data Exchange (ETDEWEB)

    Jaksic, N.; Simon-Weidner, J.; Sapper, J. [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    1998-07-01

    The WENDELSTEIN 7-X (W7-X) stellarator experiment is now in the state of its final design. The basic confinement system consists of 50 nonplanar and 20 planar superconducting coils. Meanwhile the geometrical data of the coils have been fixed. The changes with respect to the first design influenced the support concept taking into account needs on enlarged space for the different ports and nozzles. (author)

  12. How long does it take to coil an intracranial aneurysm?

    Energy Technology Data Exchange (ETDEWEB)

    Gast, Anjob N. de; Soepboer, Aelwyn; Sluzewski, Menno; Rooij, Willem J. van [St. Elisabeth Ziekenhuis, Department of Radiology, Tilburg (Netherlands); Beute, Guus N. [St. Elisabeth Ziekenhuis, Department of Neurosurgery, Tilburg (Netherlands)

    2008-01-15

    The change in the treatment of choice for intracranial aneurysms from clipping to coiling has been associated with an important change in logistics. The time needed for coiling is variable and depends on many factors. In this study, we assessed the procedural time for the coiling of 642 aneurysms and tried to identify predictors of a long procedural time. The procedural time for coiling was defined as the number of minutes between the first diagnostic angiographic run and the last angiographic run after embolization. Thus, induction of general anesthesia and catheterization of the first vessel were not included in the procedural time. A long procedural time was defined as the upper quartile of procedural times (70-158 min). Logistic regression analysis was performed for several variables. The mean procedural time was 57.3 min (median 52 min, range 15-158 min). More than half of the coiling procedures lasted between 30 and 60 min. Multiple logistic regression analysis identified the use of a supportive device (OR 5.4), procedural morbidity (OR 4.5) and large aneurysm size (OR 3.0) as independent predictors of a long procedural time. A poor clinical condition of the patient, the rupture status of the aneurysm, gender, the occurrence of procedural rupture, and aneurysm location were not related to a long procedural time. The mean time for the first 321 coiling procedures was not statistically significantly different from mean time for the last 321 procedures. With optimal logistics, coiling of most intracranial aneurysms can be performed in one to two hours, including patient handling before and after the actual coiling procedure. (orig.)

  13. Design of an MgB2 race track coil for a wind generator pole demonstration

    NARCIS (Netherlands)

    Abrahamsen, A.B.; Magnusson, N.; Jensen, B.B.; Liu, D.; Polinder, H.

    2014-01-01

    An MgB2 race track coil intended for demonstrating a down scaled pole of a 10 MW direct drive wind turbine generator has been designed. The coil consists of 10 double pancake coils stacked into a race track coil with a cross section of 84 mm x 80 mm. The length of the straight section is 0.5 m and t

  14. Design of an MgB2 race track coil for a wind generator pole demonstration

    NARCIS (Netherlands)

    Abrahamsen, A.B.; Magnusson, N.; Jensen, B.B.; Liu, D.; Polinder, H.

    2014-01-01

    An MgB2 race track coil intended for demonstrating a down scaled pole of a 10 MW direct drive wind turbine generator has been designed. The coil consists of 10 double pancake coils stacked into a race track coil with a cross section of 84 mm x 80 mm. The length of the straight section is 0.5 m and

  15. Retrieval of a Migrated Coil Using an X6 MERCI Device.

    LENUS (Irish Health Repository)

    O'Hare, A

    2009-03-31

    Summary: Coil migration is a recognised but rare complication of endovascular coiling. Many techniques are available commercially for coil retrieval. We report the case of an acute subarachnoid hemorrhage in a 54-year-old woman in which a migrated coil was successfully retrieved using an X6 MERCI device.

  16. The Effect of Axial Stress on YBCO Coils

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, W.; Anerella, M.; Cozzolino, J.P.; Gupta, R.C.; Shiroyanagi, Y.; Evangelou, E.

    2011-03-28

    The large aspect ratio of typical YBCO conductors makes them ideal for constructing solenoids from pancake style coils. An advantage of this method is that each subunit can be tested before assembly into the finished magnet. The fact that conductors are available in relatively short lengths is another reason for using such a fabrication technique. The principal drawback is the large number of joints required to connect the coils together. When very high field solenoids such as those contemplated for the muon collider are built in this way the magnetic forces between pancakes can be very large. Extensive measurements have been made on the effect of stress on short lengths of conductor, but there is little or no data on the effect of intercoil loading. The experiment described in this paper was designed to test the ability of YBCO coils to withstand these forces. A spiral wound 'pancake' coil made from YBCO coated conductor has been stressed to a pressure of 100MPa in the axial direction at 77K. In this case axial refers to the coil so that the force is applied to the edge of the conductor. The effect on the critical current was small and completely reversible. Repeatedly cycling the pressure had no measureable permanent effect on the coil. The small current change observed exhibited a slight hysteretic behaviour during the loading cycle.

  17. Low Impedance Voice Coils for Improved Loudspeaker Efficiency

    DEFF Research Database (Denmark)

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

    2015-01-01

    In modern audio systems utilizing switch-mode amplifiers the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 4 to 8 Ohms is obtained, despite modern audio amplifiers, using switch-mode techno......In modern audio systems utilizing switch-mode amplifiers the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 4 to 8 Ohms is obtained, despite modern audio amplifiers, using switch......-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. A new parameter, the drivers mass ratio, is introduced and it indicates how much a fill factor optimization will improve a driver......’s efficiency. Different voice coil winding layouts are described and their fill factors analyzed. It is found that by lowering the nominal resistance of a voice coil, using rectangular wire, one can increase the fill factor. Three voice coils are designed for a standard 10” woofer and corresponding frequency...

  18. Effect of Metal Proximity on a Pulsed Copper Coil

    Science.gov (United States)

    Johnson, H. K.; Schaffner, D. A.; Brown, M. R.; Kaur, M.; Fiedler-Kawaguchi, C.

    2016-10-01

    Generating and accelerating plasma in a stainless steel chamber affects the magnetic fields inside. These effects will decrease the field due to a pulsed coil (which will later be used to accelerate plasma) inside the chamber. This work is being done in conjunction with the Swarthmore Spheromak Experiment. Both facilities are collaborating in an attempt to accelerate and compress plasma as part of ARPA-E's Accelerating Low-Cost Plasma Heating and Assembly (ALPHA) program. Measurements of the impact of the chamber on the coil's magnetic fields were made using a B-dot probe inside the coil, which was placed at incremental distances from a metal plate. As the coil is moved from the plate, the plate's interference with the field was seen to exponentially decay. This process was repeated for stainless steel, aluminum, and copper, and a range of voltages (500-800V). At least seventy percent of the original signal was recovered within two inches. Pulsing the coil inside the stainless steel chamber resulted in signals about one third the strength of those measured outside of the chamber. The results of this experiment will be used to guide development of the stainless steel pulse-coil system for the Swarthmore ALPHA project. Work supported by ARPA-E ALPHA program.

  19. NMR of thin layers using a meanderline surface coil

    Science.gov (United States)

    Cowgill, Donald F.

    2001-01-01

    A miniature meanderline sensor coil which extends the capabilities of nuclear magnetic resonance (NMR) to provide analysis of thin planar samples and surface layer geometries. The sensor coil allows standard NMR techniques to be used to examine thin planar (or curved) layers, extending NMRs utility to many problems of modern interest. This technique can be used to examine contact layers, non-destructively depth profile into films, or image multiple layers in a 3-dimensional sense. It lends itself to high resolution NMR techniques of magic angle spinning and thus can be used to examine the bonding and electronic structure in layered materials or to observe the chemistry associated with aging coatings. Coupling this sensor coil technology with an arrangement of small magnets will produce a penetrator probe for remote in-situ chemical analysis of groundwater or contaminant sediments. Alternatively, the sensor coil can be further miniaturized to provide sub-micron depth resolution within thin films or to orthoscopically examine living tissue. This thin-layer NMR technique using a stationary meanderline coil in a series-resonant circuit has been demonstrated and it has been determined that the flat meanderline geometry has about he same detection sensitivity as a solenoidal coil, but is specifically tailored to examine planar material layers, while avoiding signals from the bulk.

  20. Automatic tuning of flexible interventional RF receiver coils.

    Science.gov (United States)

    Venook, Ross D; Hargreaves, Brian A; Gold, Garry E; Conolly, Steven M; Scott, Greig C

    2005-10-01

    Microcontroller-based circuitry was built and tested for automatically tuning flexible RF receiver coils at the touch of a button. This circuitry is robust to 10% changes in probe center frequency, is in line with the scanner, and requires less than 1 s to tune a simple probe. Images were acquired using this circuitry with a varactor-tunable 1-inch flexible probe in a phantom and in an in vitro porcine knee model. The phantom experiments support the use of automatic tuning by demonstrating 30% signal-to-noise ratio (SNR) losses for 5% changes in coil center frequency, in agreement with theoretical calculations. Comparisons between patellofemoral cartilage images obtained using a 3-inch surface coil and the surgically-implanted 1-inch flexible coil reveal a worst-case local SNR advantage of a factor of 4 for the smaller coil. This work confirms that surgically implanted coils can greatly improve resolution in small-field-of-view (FOV) applications, and demonstrates the importance and feasibility of automatically tuning such probes.

  1. First ATLAS Barrel Toroid coil casing arrives at CERN

    CERN Multimedia

    2002-01-01

    The first of eight 25-metre long coil casings for the ATLAS experiment's barrel toroid magnet system arrived at CERN on Saturday 2 March by road from Heidelberg. This structure will be part of the largest superconducting toroid magnet ever made.   The first coil casing for the toroidal magnets of Atlas arrives at Building 180. This is the start of an enormous three-dimensional jigsaw puzzle. Each of the eight sets of double pancake coils will be housed inside aluminium coil casings, which in turn will be held inside a stainless steel vacuum vessel. A huge construction, the casing that arrived at CERN measures 25 metres in length and 5 metres in width. It weighs 20 tones. And this is just the beginning of the toroid jigsaw: by early April a batch of four double pancake coils, which altogether weighs 65 tones, will arrive from Ansaldo in Italy. The first vacuum vessel will also be arriving from Felguera in Spain this month. It will take about two years for all these 25 m long structures of casings, coils a...

  2. COMPLICATION ANALYSIS OF INTRACRANIAL ANEURYSM EMBOLIZATION WITH CONTROLLABLE COILS

    Institute of Scientific and Technical Information of China (English)

    王大明; 凌锋; 王安顺

    2004-01-01

    Objective To explore the causes, prevention, and management of the complications during intracranial aneurysm embolization with controllable coils (mechanical detachable spiral, MDS; and Guglielmi detachable coil, GDC). Methods Retrospective review of 120 cases with 125 intracranial aneurysms embolized with controllable coils from March 1995 to July 1999 was conducted. The 20 accidents (in 18 cases) including aneurysm rupture, over-embolization, protrusion of coil end into the parent artery, and thrombosis of the parent artery were analyzed. Results Among the 20 accidents, there were 6 aneurysm ruptures, 6 over-embolizations (in 5cases), 6 coil protrusions, and 2 thromboses (one was secondary to coil protrusion). The embolizationrelated mortality was 3.33% (4/120), the permanent neurological deficit was 1.67% (2/120), and the transitory neurological deficit was 3.33% (4/120). The occurrence and outcome of the complications were related to the embolizing technique, the pattern of aneurysm and its parent artery, the imperfection of embolic materials, and the observation and management during embolization. Conclusion Skilled embolizing technique, better understanding of the angio-anatomy of an aneurysm and its parent artery, correct judgement and management during embolization, and improvement of embolic materials are beneficial to the reduction of complications and to the melioration of the outcome of complications.

  3. Endovascular therapy of arteriovenous fistulae with electrolytically detachable coils

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, O.; Doerfler, A.; Forsting, M.; Hartmann, M.; Kummer, R. von; Tronnier, V.; Sartor, K. [Dept. of Neuroradiology, University of Heidelberg Medical School (Germany)

    1999-12-01

    We report our experience in using Guglielmi electrolytically detachable coils (GDC) alone or in combination with other materials in the treatment of intracranial or cervical high-flow fistulae. We treated 14 patients with arteriovenous fistulae on brain-supplying vessels - three involving the external carotid or the vertebral artery, five the cavernous sinus and six the dural sinuses - by endovascular occlusion using electrolytically detachable platinum coils. The fistula was caused by trauma in six cases. In one case Ehlers-Danlos syndrome was the underlying disease, and in the remaining seven cases no aetiology could be found. Fistulae of the external carotid and vertebral arteries and caroticocavernous fistulae were reached via the transarterial route, while in all dural fistulae a combined transarterial-transvenous approach was chosen. All fistulae were treated using electrolytically detachable coils. While small fistulae could be occluded with electrolytically detachable coils alone, large fistulae were treated by using coils to build a stable basket for other types of coil or balloons. In 11 of the 14 patients, endovascular treatment resulted in complete occlusion of the fistula; in the remaining three occlusion was subtotal. Symptoms and signs were completely abolished by this treatment in 12 patients and reduced in 2. On clinical and neuroradiological follow-up (mean 16 months) no reappearance of symptoms was recorded. (orig.)

  4. [Surgical Removal of Migrated Coil after Embolization of Jejunal Variceal Bleeding: A Case Report].

    Science.gov (United States)

    Kim, Junhwan; Lee, Danbi; Oh, Kyunghwan; Lee, Mingee; So, Seol; Yang, Dong Hoon; Kim, Chan Wook; Gwon, Dong Il; Chung, Young Hwa

    2017-01-25

    Jejunal variceal bleeding is less common compared with esophagogastric varices in patients with portal hypertension. However, jejunal variceal bleeding can be fatal without treatment. Treatments include surgery, transjugular intrahepatic porto-systemic shunt (TIPS), endoscopic sclerotherapy, percutaneous coil embolization, and balloon-occluded retrograde transvenous obliteration (BRTO). Percutaneous coil embolization can be considered as an alternative treatment option for those where endoscopic sclerotherapy, surgery, TIPS or BRTO are not possible. Complications of percutaneous coil embolization have been reported, including coil migration. Herein, we report a case of migration of the coil into the jejunal lumen after percutaneous coil embolization for jejunal variceal bleeding. The migrated coil was successfully removed using surgery.

  5. Improved SNR of phased-array PERES coils via simulation study

    Energy Technology Data Exchange (ETDEWEB)

    RodrIguez, Alfredo O [Centro de Investigacion en Imagenologia e Instrumentacion Medica, Universidad Autonoma Metropolitana Iztapalapa, Av. San Rafael Atlixco 186, Mexico, DF, 09340 (Mexico); Medina, LucIa [DISCA, Instituto de Investigacion en Matematicas Aplicadas y Sistemas, Universidad Nacional Autonoma de Mexico, AP 20-728, Admo. No. 20, 01000 Mexico, DF (Mexico); Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico, DF (Mexico)

    2005-09-21

    A computational comparison of signal-to-noise ratio (SNR) was performed between a conventional phased array of two circular-shaped coils and a petal resonator surface array. The quasi-static model and phased-array optimum SNR were combined to derive an SNR formula for each array. Analysis of mutual inductance between coil petals was carried out to compute the optimal coil separation and optimum number of petal coils. Mutual interaction between coil arrays was not included in the model because this does not drastically affect coil performance. Phased arrays of PERES coils show a 114% improvement in SNR over that of the simplest circular configuration. (note)

  6. Rationally designed coiled-coil DNA looping peptides control DNA topology.

    Science.gov (United States)

    Gowetski, Daniel B; Kodis, Erin J; Kahn, Jason D

    2013-09-01

    Artificial DNA looping peptides were engineered to study the roles of protein and DNA flexibility in controlling the geometry and stability of protein-mediated DNA loops. These LZD (leucine zipper dual-binding) peptides were derived by fusing a second, C-terminal, DNA-binding region onto the GCN4 bZip peptide. Two variants with different coiled-coil lengths were designed to control the relative orientations of DNA bound at each end. Electrophoretic mobility shift assays verified formation of a sandwich complex containing two DNAs and one peptide. Ring closure experiments demonstrated that looping requires a DNA-binding site separation of 310 bp, much longer than the length needed for natural loops. Systematic variation of binding site separation over a series of 10 constructs that cyclize to form 862-bp minicircles yielded positive and negative topoisomers because of two possible writhed geometries. Periodic variation in topoisomer abundance could be modeled using canonical DNA persistence length and torsional modulus values. The results confirm that the LZD peptides are stiffer than natural DNA looping proteins, and they suggest that formation of short DNA loops requires protein flexibility, not unusual DNA bendability. Small, stable, tunable looping peptides may be useful as synthetic transcriptional regulators or components of protein-DNA nanostructures.

  7. Transforming the Energy Landscape of a Coiled-Coil Peptide via Point Mutations.

    Science.gov (United States)

    Röder, Konstantin; Wales, David J

    2017-03-14

    We analyze the effect of point mutations on the energy landscape of a coiled-coil peptide, GCN4-pLI, where the native state is a parallel tetrameric configuration formed from two identical dimers. Experimentally, a single mutation, E20S, supports both antiparallel and parallel structures. Here, we analyze the potential energy landscapes of the dimeric units for the parent sequence and four mutants, namely E20S, E20A, E20P, and E20G. Despite sharing characteristic funnels containing the parallel and antiparallel structures, the point mutations change some parts of the landscape quite dramatically, and we predict new intermediate structures and characterize the associated heat capacities. For the mutants we predict that kinked intermediate structures facilitate the transition between parallel and antiparallel morphologies, in contrast to the parent sequence. Furthermore, we predict a change from a multifunnel energy landscape in the E20S mutant to a landscape dominated by an underlying single funnel in the parent sequence, with accompanying heat capacity signatures. Our results imply that changes in the landscape due to mutations might provide useful tools for functional protein design.

  8. Biochemical and molecular dynamic simulation analysis of a weak coiled coil association between kinesin-II stalks.

    Directory of Open Access Journals (Sweden)

    Harinath Doodhi

    Full Text Available DEFINITION: Kinesin-2 refers to the family of motor proteins represented by conserved, heterotrimeric kinesin-II and homodimeric Osm3/Kif17 class of motors. BACKGROUND: Kinesin-II, a microtubule-based anterograde motor, is composed of three different conserved subunits, named KLP64D, KLP68D and DmKAP in Drosophila. Although previous reports indicated that coiled coil interaction between the middle segments of two dissimilar motor subunits established the heterodimer, the molecular basis of the association is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present a detailed heterodimeric association model of the KLP64D/68D stalk supported by extensive experimental analysis and molecular dynamic simulations. We find that KLP64D stalk is unstable, but forms a weak coiled coil heteroduplex with the KLP68D stalk when coexpressed in bacteria. Local instabilities, relative affinities between the C-terminal stalk segments, and dynamic long-range interactions along the stalks specify the heterodimerization. Thermal unfolding studies and independent simulations further suggest that interactions between the C-terminal stalk fragments are comparatively stable, whereas the N-terminal stalk reversibly unfolds at ambient temperature. CONCLUSIONS/SIGNIFICANCE: Results obtained in this study suggest that coiled coil interaction between the C-terminal stalks of kinesin-II motor subunits is held together through a few hydrophobic and charged interactions. The N-terminal stalk segments are flexible and could uncoil reversibly during a motor walk. This supports the requirement for a flexible coiled coil association between the motor subunits, and its role in motor function needs to be elucidated.

  9. Nitroxid-vermittelte Polymerisation mittels NMR-Sonden tragender Initiatoren zur Darstellung von coil-rod-coil-Blockcopolymeren

    OpenAIRE

    Tietz, Marco

    2016-01-01

    A systematic synthesis for coil-rod-coil(c-r-c) block copolymers with differing material characteristics should lead to the usage of c-r-c block copolymers as surface probes and for the study of the self assembling behavior of c-r-c block copolymers. Therefor 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) based alkoxyamines with covalently attached NMR probes where synthesized starting from nitroxides and functionalized styrenes. These alkoxyamines were used as initiators f...

  10. Testing of a Single 11 T $Nb_3Sn$ Dipole Coil Using a Dipole Mirror Structure

    Energy Technology Data Exchange (ETDEWEB)

    Zlobin, Alexander [Fermilab; Andreev, Nicolai [Fermilab; Barzi, Emanuela [Fermilab; Chlachidze, Guram [Fermilab; Kashikhin, Vadim [Fermilab; Nobrega, Alfred [Fermilab; Novitski, Igor [Fermilab; Turrioni, Daniele [Fermilab; Karppinen, Mikko [CERN; Smekens, David [CERN

    2014-07-01

    FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC. To optimize coil design parameters and fabrication process and study coil performance, a series of 1 m long dipole coils is being fabricated. One of the short coils has been tested using a dipole mirror structure. This paper describes the dipole mirror magnetic and mechanical designs, and reports coil parameters and test results.

  11. [High resolution MR imaging of the hip using pelvic phased-array coil].

    Science.gov (United States)

    Niitsu, M; Mishima, H; Itai, Y

    1997-01-01

    A pelvic phased-array coil was applied to obtain high resolution MR images of the hip. Three-mm-thick fast spinecho images were obtained in seven hips. Images with a pelvic coil enhanced delineation of acetabular labrum and articular cartilage more clearly than those with a body coil or flexible-surface coil. The use of a pelvic coil in imaging of the hip may be of diagnostic value because of its superior delineation.

  12. 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

  13. Rice Cellulose SynthaseA8 Plant-Conserved Region Is a Coiled-Coil at the Catalytic Core Entrance

    Energy Technology Data Exchange (ETDEWEB)

    Rushton, Phillip S.; Olek, Anna T.; Makowski, Lee; Badger, John; Steussy, C. Nicklaus; Carpita, Nicholas C.; Stauffacher, Cynthia V.

    2016-11-22

    The crystallographic structure of a rice (Oryza sativa) cellulose synthase, OsCesA8, plant-conserved region (P-CR), one of two unique domains in the catalytic domain of plant CesAs, was solved to 2.4 Å resolution. Two antiparallel α-helices form a coiled-coil domain linked by a large extended connector loop containing a conserved trio of aromatic residues. The P-CR structure was fit into a molecular envelope for the P-CR domain derived from small-angle X-ray scattering data. The P-CR structure and molecular envelope, combined with a homology-based chain trace of the CesA8 catalytic core, were modeled into a previously determined CesA8 small-angle X-ray scattering molecular envelope to produce a detailed topological model of the CesA8 catalytic domain. The predicted position for the P-CR domain from the molecular docking models places the P-CR connector loop into a hydrophobic pocket of the catalytic core, with the coiled-coil aligned near the entrance of the substrate UDP-glucose into the active site. In this configuration, the P-CR coiled-coil alone is unlikely to regulate substrate access to the active site, but it could interact with other domains of CesA, accessory proteins, or other CesA catalytic domains to control substrate delivery.

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

    Directory of Open Access Journals (Sweden)

    Zhuoshi Wang

    2014-04-01

    Full Text Available 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.

  15. Design of the dummy coil for magnet power supply

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang-Hwan, E-mail: kch2004@nfri.re.kr; Choi, Jae-Hoon; Jin, Jong-Kook; Lee, Dong-Keun; Kong, Jong-Dea; Joung, Nam-Young; Kim, Sang-Tae; Kim, Young-Jin; Kim, Yang-Soo; Kwon, Myeun

    2013-11-15

    Highlights: • It is necessary to confirm safety of the MPS on a dummy coil before the operating it. • We selected and designed the water cooling type dummy coil to test on the MPS's rating (12.5 kA) test. • For the design of the dummy coil, we considered requirements about electrical, structural and water cooling. • We will test as the rating power after MPS upgrade and that test will do before every KSTAR campaign. -- Abstract: It is necessary to test it on a dummy coil, before using a magnet power supply (MPS) to energize a Poloidal Field (PF) coil in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The dummy coil should accept the same large current from the MPS as the PF coil and be within the capability of the utilities located at the KSTAR site. Therefore a coil design based on the characteristics of the MPS and other restrictive conditions needed to be made. There are three requirements to be met in the design: an electrical requirement, a structural requirement, and a water cooling requirement. The electrical requirement was that the coil should have an inductance of 40 mH. For the structural requirement, the material should be non magnetic. The coil support structure and water cooling manifold were made of SUS 304. The water cooling requirement was that there should be sufficient flow rate so that the temperature rise ΔT should not exceed 12 °C for operation at 12.5 kA for 5 min. Square cross-section hollow conductor with dimensions of 38.1 mm × 38.1 mm was used with a 25.4 mm center hole for cooling water. However, as a result of tests, it was found that the electrical and structural requirements were satisfied but that the water cooling was over designed. It is imperative that the verification will be redone for a test with 12.5 kA for 5 min.

  16. Coiled-coil interaction of N-terminal 36 residues of cyclase-associated protein with adenylyl cyclase is sufficient for its function in Saccharomyces cerevisiae ras pathway.

    Science.gov (United States)

    Nishida, Y; Shima, F; Sen, H; Tanaka, Y; Yanagihara, C; Yamawaki-Kataoka, Y; Kariya, K; Kataoka, T

    1998-10-23

    In the budding yeast Saccharomyces cerevisiae, association with the 70-kDa cyclase-associated protein (CAP) is required for proper response of adenylyl cyclase to Ras proteins. We show here that a small segment comprising the N-terminal 36 amino acid residues of CAP is sufficient for association with adenylyl cyclase as well as for its function in the Ras-adenylyl cyclase pathway as assayed by the ability to confer RAS2(Val-19)-dependent heat shock sensitivity to yeast cells. The CAP-binding site of adenylyl cyclase was mapped to a segment of 119 amino acid residues near its C terminus. Both of these regions contained tandem repetitions of a heptad motif alphaXXalphaXXX (where alpha represents a hydrophobic amino acid and X represents any amino acid), suggesting a coiled-coil interaction. When mutants of CAP defective in associating with adenylyl cyclase were isolated by screening of a pool of randomly mutagenized CAP, they were found to carry substitution mutations in one of the key hydrophobic residues in the heptad repeats. Furthermore, mutations of the key hydrophobic residues in the heptad repeats of adenylyl cyclase also resulted in loss of association with CAP. These results indicate the coiled-coil mechanism as a basis of the CAP-adenylyl cyclase interaction.

  17. Electrical engineering. Coiling of rotating machines; Genie electrique. Bobinage des machines tournantes a courant alternatif

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Michel, J. [Moteurs Leroy Somer, 16 - Angouleme (France)

    2001-02-01

    This article treats of the poly-phase coiling of AC rotating machines. For simplification reasons, the study has been limited to tri-phase coils, but the theoretical calculations can be extended to any other number of phases. The coils described are those encountered in the stators of synchronous and asynchronous machines and in the rotors of asynchronous machines with rings. The qualitative, quantitative and practical aspects are presented successively: 1 - magnetic field produced by a coil (single turn, distributed coil, coil schemes, multi-polarity coils); 2 - field generated by a tri-phase coil (rotating field theorem, qualitative influence of space harmonics); 3 - quantitative analysis of coil properties (magneto-motive force generated by coils, harmonic decomposition of the magneto-motive force wave, global coiling coefficients); 4 - comparative study of different regular coils (diametrical step, shortened step, distributed); 5 - irregular coils; 6 - other double polarity coils (Dahlander coupling, other multiple polarity possibilities); 7 - reduction of teething harmonics (determination of optimal twisting, influence of inclination on the dimensioning of machines); 8 - practical realization of coils (insulation, insertion inside the machine). (J.S.)

  18. [Development of RF coil of permanent magnet mini-magnetic resonance imager and mouse imaging experiments].

    Science.gov (United States)

    Hou, Shulian; Xie, Huantong; Chen, Wei; Wang, Guangxin; Zhao, Qiang; Li, Shiyu

    2014-10-01

    In the development of radio frequency (RF) coils for better quality of the mini-type permanent magnetic resonance imager for using in the small animal imaging, the solenoid RF coil has a special advantage for permanent magnetic system based on analyses of various types.of RF coils. However, it is not satisfied for imaging if the RF coils are directly used. By theoretical analyses of the magnetic field properties produced from the solenoid coil, the research direction was determined by careful studies to raise further the uniformity of the magnetic field coil, receiving coil sensitivity for signals and signal-to-noise ratio (SNR). The method had certain advantages and avoided some shortcomings of the other different coil types, such as, birdcage coil, saddle shaped coil and phased array coil by using the alloy materials (from our own patent). The RF coils were designed, developed and made for keeled applicable to permanent magnet-type magnetic resonance imager, multi-coil combination-type, single-channel overall RF receiving coil, and applied for a patent. Mounted on three instruments (25 mm aperture, with main magnetic field strength of 0.5 T or 1.5 T, and 50 mm aperture, with main magnetic field strength of 0.48 T), we performed experiments with mice, rats, and nude mice bearing tumors. The experimental results indicated that the RF receiving coil was fully applicable to the permanent magnet-type imaging system.

  19. Structural mapping of the coiled-coil domain of a bacterial condensin and comparative analyses across all domains of life suggest conserved features of SMC proteins.

    Science.gov (United States)

    Waldman, Vincent M; Stanage, Tyler H; Mims, Alexandra; Norden, Ian S; Oakley, Martha G

    2015-06-01

    The structural maintenance of chromosomes (SMC) proteins form the cores of multisubunit complexes that are required for the segregation and global organization of chromosomes in all domains of life. These proteins share a common domain structure in which N- and C- terminal regions pack against one another to form a globular ATPase domain. This "head" domain is connected to a central, globular, "hinge" or dimerization domain by a long, antiparallel coiled coil. To date, most efforts for structural characterization of SMC proteins have focused on the globular domains. Recently, however, we developed a method to map interstrand interactions in the 50-nm coiled-coil domain of MukB, the divergent SMC protein found in γ-proteobacteria. Here, we apply that technique to map the structure of the Bacillus subtilis SMC (BsSMC) coiled-coil domain. We find that, in contrast to the relatively complicated coiled-coil domain of MukB, the BsSMC domain is nearly continuous, with only two detectable coiled-coil interruptions. Near the middle of the domain is a break in coiled-coil structure in which there are three more residues on the C-terminal strand than on the N-terminal strand. Close to the head domain, there is a second break with a significantly longer insertion on the same strand. These results provide an experience base that allows an informed interpretation of the output of coiled-coil prediction algorithms for this family of proteins. A comparison of such predictions suggests that these coiled-coil deviations are highly conserved across SMC types in a wide variety of organisms, including humans. © 2015 Wiley Periodicals, Inc.

  20. Magnetic field modeling with a set of individual localized coils.

    Science.gov (United States)

    Juchem, Christoph; Nixon, Terence W; McIntyre, Scott; Rothman, Douglas L; de Graaf, Robin A

    2010-06-01

    A set of generic, circular individual coils is shown to be capable of generating highly complex magnetic field distributions in a flexible fashion. Arbitrarily oriented linear field gradients can be generated in three-dimensional as well as sliced volumes at amplitudes that allow imaging applications. The multi-coil approach permits the simultaneous generation of linear MRI encoding fields and complex shim fields by the same setup, thereby reducing system complexity. The choice of the sensitive volume over which the magnetic fields are optimized remains temporally and spatially variable at all times. The restriction of the field synthesis to experimentally relevant, smaller volumes such as single slices directly translates into improved efficiency, i.e. higher magnetic field amplitudes and/or reduced coil currents. For applications like arterial spin labeling, signal spoiling and diffusion weighting, perfect linearity of the gradient fields is not required and reduced demands on accuracy can also be readily translated into improved efficiency. The first experimental realization was achieved for mouse head MRI with 24 coils that were mounted on the surface of a cylindrical former. Oblique linear field gradients of 20 kHz/cm (47 mT/m) were generated with a maximum current of 1.4A which allowed radial imaging of a mouse head. The potential of the new approach for generating arbitrary magnetic field shapes is demonstrated by synthesizing the more complex, higher order spherical harmonic magnetic field distributions X2-Y2, Z2 and Z2X. The new multi-coil approach provides the framework for the integration of conventional imaging and shim coils into a single multi-coil system in which shape, strength, accuracy and spatial coverage of the magnetic field can be specifically optimized for the application at hand.

  1. Effect of pH, urea, peptide length, and neighboring amino acids on alanine alpha-proton random coil chemical shifts.

    Science.gov (United States)

    Carlisle, Elizabeth A; Holder, Jessica L; Maranda, Abby M; de Alwis, Adamberage R; Selkie, Ellen L; McKay, Sonya L

    2007-01-01

    Accurate random coil alpha-proton chemical shift values are essential for precise protein structure analysis using chemical shift index (CSI) calculations. The current study determines the chemical shift effects of pH, urea, peptide length and neighboring amino acids on the alpha-proton of Ala using model peptides of the general sequence GnXaaAYaaGn, where Xaa and Yaa are Leu, Val, Phe, Tyr, His, Trp or Pro, and n = 1-3. Changes in pH (2-6), urea (0-1M), and peptide length (n = 1-3) had no effect on Ala alpha-proton chemical shifts. Denaturing concentrations of urea (8M) caused significant downfield shifts (0.10 +/- 0.01 ppm) relative to an external DSS reference. Neighboring aliphatic residues (Leu, Val) had no effect, whereas aromatic amino acids (Phe, Tyr, His and Trp) and Pro caused significant shifts in the alanine alpha-proton, with the extent of the shifts dependent on the nature and position of the amino acid. Smaller aromatic residues (Phe, Tyr, His) caused larger shift effects when present in the C-terminal position (approximately 0.10 vs. 0.05 ppm N-terminal), and the larger aromatic tryptophan caused greater effects in the N-terminal position (0.15 ppm vs. 0.10 C-terminal). Proline affected both significant upfield (0.06 ppm, N-terminal) and downfield (0.25 ppm, C-terminal) chemical shifts. These new Ala correction factors detail the magnitude and range of variation in environmental chemical shift effects, in addition to providing insight into the molecular level interactions that govern protein folding.

  2. Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

    Science.gov (United States)

    Weinberger, Oliver; Winter, Lukas; Dieringer, Matthias A; Els, Antje; Oezerdem, Celal; Rieger, Jan; Kuehne, Andre; Cassara, Antonino M; Pfeiffer, Harald; Wetterling, Friedrich; Niendorf, Thoralf

    2016-01-01

    The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation. Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated. Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit. Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants.

  3. Studies on the performance of different coiled column configurations for compact type-I countercurrent chromatography.

    Science.gov (United States)

    Yang, Yi; Gu, Dongyu; Aisa, Haji Akber; Ito, Yoichiro

    2011-05-01

    Three types of novel coiled column configurations, i.e. a triangular coiled column and elliptical coiled columns I and II, were designed for type-I countercurrent chromatography and their performances were evaluated with two solvent systems each with suitable test samples. Three dinitrophenyl (DNP) amino acids (DNP-DL-glu, DNP-β-ala and DNP-L-ala) were separated with a moderately hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1 M hydrochloric acid (1:1:1:1, v/v), while two dipeptides (tryptophyl-tyrosine and valyl-tyrosine) were separated with a polar solvent system composed of 1-butanol-acetic acid-water (4.75:0.25:5, v/v). The overall results indicated that the performance of compact type-I countercurrent chromatography was improved by elliptical coiled column I which was mounted with its maximum coil diameter perpendicular to the surface of the column holder. Hydrodynamic effects involved in these separations were discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Temperature Profile Measurements During Heat Treatment of BSCCO 2212 Coils

    Energy Technology Data Exchange (ETDEWEB)

    Tollestrup, Alvin; /Fermilab

    2011-04-14

    The temperature profile of two different BSCCO 2212 coils has been analyzed. The profiles are obtained from thermocouples imbedded in the windings during the heat treatment that activates the 2212. The melting and freezing of the 2212 is clearly observed. A model that describes the data and can be used to guide the processing of new coils has been developed. We have obtained the thermal history of two BSCCO coils, one from NHMFL (1) that had 10 layers of 1 mm diameter wire with 0.15 mm insulation and a second coil from OST that had 24 layers with similar insulation and conductor size. Both coils had thermocouples imbedded in the windings and excellent recordings of the temperature over the whole reaction cycle were available for analysis. There are several features that we will address in this note. Measurements have shown that the I{sub c} of the conductor is a sensitive function of its thermal history. This brings up the question of the absolute accuracy of the thermometry in the range around 882 C, the MP of 2212. The reference for the treatment profile is really related to this MP and to small deviations around it. Since the heat of fusion of 2212 is rather large, it generates a clear signal during the melting and cooling transition that automatically generates the relative temperature markers. The physics is the same as the way ice in water maintains an isothermal environment until it is all melted. A related question is the thermal response time of the coil package. The temperature cycles that are being used to optimize strand and small coils can have rapid changes easily implemented whereas a large coil may have such a large thermal time constant that the optimum cycle may not be attainable. A simple analytical model that works well for small solenoids has been developed and an ANSYS (5) program that works for larger coils with more complicated geometry has been set up but will not be discussed in this note.

  5. Hinderin, a five-domains protein including coiled-coil motifs that binds to SMC3

    Directory of Open Access Journals (Sweden)

    Ghiselli Giancarlo

    2005-01-01

    Full Text Available Abstract Background The structural maintenance of chromosome proteins SMC1 and SMC3 play an important role in the maintenance of chromosomal integrity by preventing the premature separation of the sister chromatids at the onset of anaphase. The two proteins are constitutive components of the multimeric complex cohesin and form dimers by interacting at their central globular regions. Results In order to identify proteins that by binding to SMC3 may interfere with the protein dimerization process, a human cDNA library was screened by the yeast two-hybrid system by using the hinge region of SMC3 as bait. This has lead to the identification of Hinderin, a novel five domains protein including two coiled-coil motifs and sharing a strikingly structural similarity to the SMC family of proteins. Hinderin is ubiquitously expressed in human tissues. Orthologue forms of the protein are present in other vertebrates but not in lower organisms. A mapping of the interaction sites revealed that the N- and C-terminal globular domains mediate the binding of Hinderin to SMC3. Hinderin/SMC3 complexes could be recovered by immunoprecipitation from cell lysates using an anti-SMC3 antibody, thus demonstrating that the two proteins interact in vivo. On the contrary, Hinderin did not interact with SMC1. In vivo the rate of SMC1/SMC3 interaction was decreased by the ectopic expression of Hinderin. Conclusions Hinderin is a novel binding partner of SMC3. Based on its ability to modulate SMC1/SMC3 interaction we postulate that Hinderin affects the availability of SMC3 to engage in the formation of multimeric protein complexes.

  6. Association of polyalanine and polyglutamine coiled coils mediates expansion disease-related protein aggregation and dysfunction.

    Science.gov (United States)

    Pelassa, Ilaria; Corà, Davide; Cesano, Federico; Monje, Francisco J; Montarolo, Pier Giorgio; Fiumara, Ferdinando

    2014-07-01

    The expansion of homopolymeric glutamine (polyQ) or alanine (polyA) repeats in certain proteins owing to genetic mutations induces protein aggregation and toxicity, causing at least 18 human diseases. PolyQ and polyA repeats can also associate in the same proteins, but the general extent of their association in proteomes is unknown. Furthermore, the structural mechanisms by which their expansion causes disease are not well understood, and these repeats are generally thought to misfold upon expansion into aggregation-prone β-sheet structures like amyloids. However, recent evidence indicates a critical role for coiled-coil (CC) structures in triggering aggregation and toxicity of polyQ-expanded proteins, raising the possibility that polyA repeats may as well form these structures, by themselves or in association with polyQ. We found through bioinformatics screenings that polyA, polyQ and polyQA repeats have a phylogenetically graded association in human and non-human proteomes and associate/overlap with CC domains. Circular dichroism and cross-linking experiments revealed that polyA repeats can form--alone or with polyQ and polyQA--CC structures that increase in stability with polyA length, forming higher-order multimers and polymers in vitro. Using structure-guided mutagenesis, we studied the relevance of polyA CCs to the in vivo aggregation and toxicity of RUNX2--a polyQ/polyA protein associated with cleidocranial dysplasia upon polyA expansion--and found that the stability of its polyQ/polyA CC controls its aggregation, localization and toxicity. These findings indicate that, like polyQ, polyA repeats form CC structures that can trigger protein aggregation and toxicity upon expansion in human genetic diseases. © The Author 2014. Published by Oxford University Press.

  7. Novel Anti-Nicotine Vaccine Using a Trimeric Coiled-Coil Hapten Carrier.

    Directory of Open Access Journals (Sweden)

    Keith D Miller

    Full Text Available Tobacco addiction represents one of the largest public health problems in the world and is the leading cause of cancer and heart disease, resulting in millions of deaths a year. Vaccines for smoking cessation have shown considerable promise in preclinical models, although functional antibody responses induced in humans are only modestly effective in preventing nicotine entry into the brain. The challenge in generating serum antibodies with a large nicotine binding capacity is made difficult by the fact that this drug is non-immunogenic and must be conjugated as a hapten to a protein carrier. To circumvent the limitations of traditional carriers like keyhole limpet hemocyanin (KLH, we have synthesized a short trimeric coiled-coil peptide (TCC that creates a series of B and T cell epitopes with uniform stoichiometry and high density. Here we compared the relative activities of a TCC-nic vaccine and two control KLH-nic vaccines using Alum as an adjuvant or GLA-SE, which contains a synthetic TLR4 agonist formulated in a stable oil-in-water emulsion. The results showed that the TCC's high hapten density correlated with a better immune response in mice as measured by anti-nicotine Ab titer, affinity, and specificity, and was responsible for a reduction in anti-carrier immunogenicity. The Ab responses achieved with this synthetic vaccine resulted in a nicotine binding capacity in serum that could prevent >90% of a nicotine dose equivalent to three smoked cigarettes (0.05 mg/kg from reaching the brain.

  8. Performance of Upgraded Cooling System for Lhd Helical Coils

    Science.gov (United States)

    Hamaguchi, S.; Imagawa, S.; Obana, T.; Yanagi, N.; Moriuchi, S.; Sekiguchi, H.; Oba, K.; Mito, T.; Motojima, O.; Okamura, T.; Semba, T.; Yoshinaga, S.; Wakisaka, H.

    2008-03-01

    Helical coils of the Large Helical Device (LHD) are large scale superconducting magnets for heliotron plasma experiments. The helical coils had been cooled by saturated helium at 4.4 K, 120 kPa until 2005. An upgrade of the cooling system was carried out in 2006 in order to improve the cryogenic stability of the helical coils and then it has been possible to supply the coils with subcooled helium at 3.2 K, 120 kPa. A designed mass flow of the supplied subcooled helium is 50 g/s. The subcooled helium is generated at a heat exchanger in a saturated helium bath. A series of two centrifugal cold compressors with gas foil bearing is utilized to lower the helium pressure in the bath. The supplied helium temperature is regulated by rotational speed of the cold compressors and power of a heater in the bath. The mass flow of the supplied helium is also controlled manually by a supply valve and its surplus is evaporated by ten heaters at the outlet above the coils. In the present study, the performance of the cooling system has been investigated and a stable operating method has also developed. As the result, it was confirmed that the performance of the upgraded cooling system satisfies the requirements.

  9. Novel TMS coils designed using an inverse boundary element method

    Science.gov (United States)

    Cobos Sánchez, Clemente; María Guerrero Rodriguez, Jose; Quirós Olozábal, Ángel; Blanco-Navarro, David

    2017-01-01

    In this work, a new method to design TMS coils is presented. It is based on the inclusion of the concept of stream function of a quasi-static electric current into a boundary element method. The proposed TMS coil design approach is a powerful technique to produce stimulators of arbitrary shape, and remarkably versatile as it permits the prototyping of many different performance requirements and constraints. To illustrate the power of this approach, it has been used for the design of TMS coils wound on rectangular flat, spherical and hemispherical surfaces, subjected to different constraints, such as minimum stored magnetic energy or power dissipation. The performances of such coils have been additionally described; and the torque experienced by each stimulator in the presence of a main magnetic static field have theoretically found in order to study the prospect of using them to perform TMS and fMRI concurrently. The obtained results show that described method is an efficient tool for the design of TMS stimulators, which can be applied to a wide range of coil geometries and performance requirements.

  10. Background field coils for the High Field Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Zbasnik, J.P.; Cornish, D.N.; Scanlan, R.M.; Jewell, A.M.; Leber, R.L.; Rosdahl, A.R.; Chaplin, M.R.

    1980-09-22

    The High Field Test Facility (HFTF), presently under construction at LLNL, is a set of superconducting coils that will be used to test 1-m-o.d. coils of prototype conductors for fusion magnets in fields up to 12 T. The facility consists of two concentric sets of coils; the outer set is a stack of Nb-Ti solenoids, and the inner set is a pair of solenoids made of cryogenically-stabilized, multifilamentary Nb/sub 3/Sn superconductor, developed for use in mirror-fusion magnets. The HFTF system is designed to be parted along the midplane to allow high-field conductors, under development for Tokamak fusion machines, to be inserted and tested. The background field coils were wound pancake-fashion, with cold-welded joints at both the inner and outer diameters. Turn-to-turn insulation was fabricated at LLNL from epoxy-fiberglass strip. The coils were assembled and tested in our 2-m-diam cryostat to verify their operation.

  11. Cryocooled Facilities for Superconducting Coils Testing in Gaseous Helium

    Science.gov (United States)

    Naumov, A. V.; Keilin, V. E.; Kovalev, I. A.; Surin, M. I.; Shcherbakov, V. I.; Shevchenko, S. A.; Ilin, A. A.

    Two superconducting coil test facilities equipped by Sumitomo SRDK-415D cryocoolers were developed, manufactured and tested. The motivation for their constructing was to make cheaper the testing (and especially training of LTS magnets) by liquid helium (LHe) saving. It is well known that the helium price increases rapidly and this tendency most probably will continue for a long time, as the demand of helium grows faster than its production. The utilization of heat-exchange gas considerably reduces many problems, that arise in the design of completely dry LTS magnets. The goal was to decrease or even completely avoid the consumption of rather expensive liquid helium for testing the laboratory size Nb-Ti and Nb3Sn coils including their training process. Several superconducting magnets were tested by using these facilities. For example, the first facility was successfully used for testing of 13 T, 60 kg coil cooled by cryocooler in helium gas (several torr pressure) heat exchange atmosphere. The precooling time was about 45 hours. The quench current (240 A at 4.2 K) was equal to that reached in the pool boiling LHe cryostat. The second facility with 420 mm wide access bore can be used for testing of corresponding size superconducting coils with very modest consumption of liquid helium with its level well below the lower flange of the coil. Each test facility is equipped by 2 pairs of HTS current leads. Design and operational experience of one of them is described.

  12. Power Supply Changes for NSTX Resistive Wall Mode Coils

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, S S.

    2013-06-28

    The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. Prior to 2004, the NSTX power system was feeding twelve (12) circuits in the machine. In 2004 the Resistive Wall Mode (RWM) Coils were installed on the machine to correct error fields. There are six of these coils installed around the machine in the mid-plane. Since these coils need fast and accurate controls, a Switching Power Amplifier (SPA) with three sub-units was procured, installed and commissioned along with other power loop components. Two RWM Coils were connected in series and fed from one SPA sub-unit. After the initial RWM campaign, operational requirements evolved such that each of the RWM coils now requires separate power and control. Hence a second SPA with three sub-units has been procured and installed. The second unit is of improved design and has the controls and power components completely isolated. The existing thyristor rectifier is used as DC Link to both of the Switching Power Amplifiers. The controls for the RWM are integrated into the overall computer control of the DC Power systems for NSTX. This paper describes the design changes in the RWM Power system for NSTX.

  13. Magnetic resonance butterfly coils: Design and application for hyperpolarized 13C studies

    DEFF Research Database (Denmark)

    Giovannetti, Giulio; Frijia, Francesca; Attanasio, Simona

    2013-01-01

    of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance. This work presents magnetostatic simulations and tests of two butterfly coils with different geometries, both designed for 13C hyperpolarized studies of pig heart with a clinical...... 3T scanner. In particular, the paper provides details of the design, modeling, construction and application of the butterfly style coils. While both coils could be successfully employed in single configuration (linear mode), the second prototype was used to design a quadrature surface coil...... constituted by the butterfly and a circular loop both in receive (RX) mode while using a birdcage coil as transmitter (TX). The performance of this coils configuration was compared with the single TX/RX birdcage coil, in order to verify the advantage of the proposed configuration over the volume coil...

  14. Flow diverter assisted coil embolization of a very small ruptured ophthalmic artery aneurysm.

    Science.gov (United States)

    Dornbos, David; Pillai, Promod; Sauvageau, Eric

    2016-06-01

    Small ruptured aneurysms present a unique problem to endovascular therapy. We report a case in which a patient presented with subarachnoid hemorrhage and a very small ruptured ophthalmic artery aneurysm, for which endovascular therapy was preferred secondary to severe cardiac comorbidities. Due to the aneurysm size, a small 1.5 mm coil was needed, but presented a significant risk of migration. Conventional stent assisted coiling was considered suboptimal as the small coil could have easily migrated through the strut. We present a novel technique of flow diverter assisted coil embolization in which a coil was placed within the aneurysm and a pipeline embolization device was then partially deployed, jailing the microcatheter and coil mass. Once in place, the coil was detached, securing the aneurysm, and preventing coil migration. Through the use of a flow diverter, some degree of aneurysm protection would still be expected in the event of coil migration toward the ophthalmic artery origin.

  15. Design of a quadrature surface coil for hyperpolarized 13C MRS cardiac metabolism studies in pigs

    DEFF Research Database (Denmark)

    Giovannetti, G.; Frijia, F.; Hartwig, V.;

    2013-01-01

    This work describes the design of a quadrature surface coil constituted by a circular loop and a butterfly coil, employed in transmit/receive (TX/RX) mode for hyperpolarized 13C studies of pig heart with a clinical 3T scanner. The coil characterization is performed by developing an SNR model...... for coil performance evaluation in terms of coil resistance, sample-induced resistance and magnetic field pattern. Experimental SNR-vs.-depth profiles, extracted from the [1-13C]acetate phantom chemical shift image (CSI), showed good agreement with the theoretical SNR-vs.-depth profiles. Moreover......, the performance of the quadrature coil was compared with the single TX/RX circular and TX/RX butterfly coil, in order to verify the advantage of the proposed configuration over the single coils throughout the volume of interest for cardiac imaging in pig. Finally, the quadrature surface coil was tested...

  16. Theoretical signal-to-noise ratio of a slotted surface coil for magnetic resonance imaging

    CERN Document Server

    Ocegueda, K; Solis, S E; Rodriguez, A O

    2011-01-01

    The analytical expression for the signal-to-noise ratio of a slotted surface coil with an arbitrary number of slots was derived using the quasi-static approach. This surface coil based on the vane-type magnetron tube. To study the coil perfomance, the theoretical signal-to-noise ratio predictions of this coil design were computed using a different number of slots. Results were also compared with theoretical results obtained for a circular coil with similar dimensions. It can be appreciated that slotted surface coil performance improves as the number of coils increases and, outperformed the circular-shaped coil. This makes it a good candidate for other MRI applications involving coil array techniques.

  17. Crowding effect on helix-coil transition: Beyond entropic stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Koutsioubas, A.; Lairez, D.; Combet, S.; Longeville, S. [Laboratoire Leon Brillouin, CEA/CNRS UMR 12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France); Fadda, G. C. [Laboratoire Leon Brillouin, CEA/CNRS UMR 12, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France); Universite Paris 13, UFR SMBH, 93017 Bobigny (France); Zalczer, G. [Service de Physique de l' Etat Condense, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France)

    2012-06-07

    We report circular dichroism measurements on the helix-coil transition of poly(L-glutamic acid) in solution with polyethylene glycol (PEG) as a crowding agent. The PEG solutions have been characterized by small angle neutron scattering and are well described by the picture of a network of mesh size {xi}, usual for semi-dilute chains in good solvent. We show that the increase of PEG concentration stabilizes the helices and increases the transition temperature. But more unexpectedly, we also notice that the increase of concentration of crowding agent reduces the mean helix extent at the transition, or in other words reduces its cooperativity. This result cannot be taken into account for by an entropic stabilization mechanism. Comparing the mean length of helices at the transition and the mesh size of the PEG network, our results strongly suggest two regimes: helices shorter or longer than the mesh size.

  18. Rebleeding of a Splenic Artery Aneurysm after Coil Embolisation

    Directory of Open Access Journals (Sweden)

    Kyra D. Kingma

    2016-01-01

    Full Text Available Background. Splenic artery aneurysm (SAA is an uncommon and difficult diagnosis. SAA is more common in females. Only 20% of SAA is symptomatic and may present as a rupture. A ruptured SAA is associated with a 25% mortality rate. Case Presentation. We present a case of a male patient with a bleeding SAA that rapidly increased in size. Distal coiling was technically impossible and despite proximal coil embolisation the SAA continued to bleed. A laparotomy including splenectomy and partial pancreatectomy was performed with an uneventful patient recovery. Discussion. Endovascular management is currently considered the optimal treatment of SAA. However, careful monitoring and follow-up is needed after embolisation as rapid recanalization of the SAA may possibly occur, especially when distal coiling of the aneurysm is unsuccessful. Conclusion. Endovascular treatment of an SAA is not necessarily effective. Surgeons must be prepared to perform open procedures to further reduce mortality rates.

  19. Impact response by a foamlike forest of coiled carbon nanotubes

    Science.gov (United States)

    Daraio, Chiara; Nesterenko, Vitali F.; Jin, Sungho; Wang, Wei; Rao, Apparao M.

    2006-09-01

    We studied the dynamic response of a foamlike forest of coiled carbon nanotubes under high strain rate deformation using a simple drop-ball test. The method is based on measuring the dynamic force between the ball and the foam on the substrate during the stages of penetration and restitution. The analysis of the forest's morphology after impact has shown no trace of plastic deformation and a full recovery of the foamlike layer of coiled carbon nanotubes under various impact velocities. The contact force exhibits a strongly nonlinear dependence on displacement and appears fundamentally different from the response of a forest of straight carbon nanotubes, and from the Hertzian type of plane-sphere interaction. "Brittle" fracture of the foamlike layer is observed after repeated high velocity impacts. Such layers of coiled nanotubes may be used as a strongly nonlinear spring in discrete systems for monitoring their dynamic behavior and as a nanostructure for localized microimpact protection.

  20. Thickness Effect of Micro Speaker Copper Coil Fabrication Process

    Directory of Open Access Journals (Sweden)

    F. L. AYAT

    2011-07-01

    Full Text Available This paper present the advantage of using electroplating for making the thick layer of copper over the sputtering. The purpose of this paper is to fabricate the copper coil for microspeaker. The design and simulation of this copper coil shows that the 15 um thickness is needed. In order to fabricate this coil, copper plating is used. The electro-deposition process is well suited to make films of metals such as copper, gold and nickel. The films can be made in any thickness from ~1 µm to >100 µm. The deposition is best controlled when used with an external electrical potentiostate. However, it requires electrical contact to the substrate when immersed in the liquid bath. In any process, the surface of the substrate must have an electrically conducting coating before the deposition can be done. The result of this experimental research shows the easy and cheap way to fabricate the thick layer of copper for microspeacker fabrication.

  1. Voice Coil Percussive Mechanism Concept for Hammer Drill

    Science.gov (United States)

    Okon, Avi

    2009-01-01

    A hammer drill design of a voice coil linear actuator, spring, linear bearings, and a hammer head was proposed. The voice coil actuator moves the hammer head to produce impact to the end of the drill bit. The spring is used to store energy on the retraction and to capture the rebound energy after each impact for use in the next impact. The maximum actuator stroke is 20 mm with the hammer mass being 200 grams. This unit can create impact energy of 0.4 J with 0.8 J being the maximum. This mechanism is less complex than previous devices meant for the same task, so it has less mass and less volume. Its impact rate and energy are easily tunable without changing major hardware components. The drill can be driven by two half-bridges. Heat is removed from the voice coil via CO2 conduction.

  2. Progress on the Coupling Coil for the MICE Channel

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A.; Li, D.; Virostek, S.P.; Lau, W.; Witte, H.; Yang,S.Q.; Drumm, P.; Ivanyushenkov, Y.

    2005-05-08

    This report describes the progress on the coupling magnet for the international Muon Ionization Cooling Experiment (MICE). MICE consists of two cells of a SFOFO cooling channel that is similar to that studied in the level 2 study of a neutrino factory. The MICE RF coupling coil module (RFCC module) consists of a 1.56 m diameter superconducting solenoid, mounted around four cells of conventional 201.25 MHz closed RF cavities. This report discusses the progress that has been made on the superconducting coupling coil that is around the center of the RF coupling module. This report describes the process by which one would cool the coupling coil using a single small 4 K cooler. In addition, the coupling magnet power system and quench protection system are also described.

  3. The correspondence between water temperature and coiling direction in Bulimina

    Science.gov (United States)

    Collins, Laurel S.

    1990-06-01

    The influence of temperature on the direction of coiling in the benthic foraminifera Bulimina marginata d'Orbigny and B. aculeata d'Orbigny is investigated by direct comparison of specimens and temperature data measured at or near the sites of collection. Nine samples from the Gulf of Mexico and 16 samples from the Gulf of Maine south to New Jersey are used. These areas include cold temperate and subtropical regions, the continental shelf, slope, and a semirestricted gulf. Complicating factors of life cycle stage and possible ontogenetic change are eliminated. Dextrality is strongly associated with warm temperatures, but cold temperatures do not produce predominantly sinistrally coiled individuals. This is the first demonstration of an unambiguous correlation between temperature and coiling direction in benthic foraminifera.

  4. A current limiter with superconducting coil for magnetic field shielding

    Science.gov (United States)

    Kaiho, K.; Yamaguchi, H.; Arai, K.; Umeda, M.; Yamaguchi, M.; Kataoka, T.

    2001-05-01

    The magnetic shield type superconducting fault current limiter have been built and successfully tested in ABB corporate research and so on. The device is essentially a transformer in which the secondary winding is the superconducting tube. However, due to the large AC losses and brittleness of the superconducting bulk tube, they have not yet entered market. A current limiter with superconducting coil for the magnetic field shielding is considered. By using the superconducting coil made by the multi-filamentary high Tc superconductor instead of the superconducting bulk tube, the AC losses can be reduced due to the reduced superconductor thickness and the brittleness of the bulk tube can be avoidable. This paper presents a preliminary consideration of the magnetic shield type superconducting fault current limiter with superconducting coil as secondary winding and their AC losses in comparison to that of superconducting bulk in 50 Hz operation.

  5. Stability improvement for coil position locking of joule balance

    Science.gov (United States)

    Bai, Yang; Liu, Yongmeng; Lu, Yunfeng; Hu, Pengcheng; Wang, Dawei; Li, Zhengkun; Tan, Jiubin; Zhang, Zhonghua

    2017-08-01

    The relative vertical position locking precision between the exciting and suspended coils is an important uncertainty for the Planck constant traceability in joule balance. In order to improve the relative vertical position locking precision, several stability experiments are conducted. The stability characteristics of the suspended and exciting coils are measured using a six-axis laser interferometer system; meanwhile, the effectiveness of the active vibration isolation table is measured using a vibration measurement sensor. The piezoelectric ceramic actuators with PID controller are used to compensate the relative vertical displacement drifts while a six-axis laser interferometer system is used to measure the positions of two coils. Experimental results show that the relative vertical position is stably locked.

  6. The normal zone propagation in ATLAS B00 model coil

    CERN Document Server

    Boxman, E W; ten Kate, H H J

    2002-01-01

    The B00 model coil has been successfully tested in the ATLAS Magnet Test Facility at CERN. The coil consists of two double pancakes wound with aluminum stabilized cables of the barrel- and end-cap toroids conductors for the ATLAS detector. The magnet current is applied up to 24 kA and quenches are induced by firing point heaters. The normal zone velocity is measured over a wide range of currents by using pickup coils, voltage taps and superconducting quench detectors. The signals coming from various sensors are presented and analyzed. The results extracted from the various detection methods are in good agreement. It is found that the characteristic velocities vary from 5 to 20 m/s at 15 and 24 kA respectively. In addition, the minimum quench energies at different applied magnet currents are presented. (6 refs).

  7. Miniature coils for producing pulsed inplane magnetic fields for nanospintronics

    Energy Technology Data Exchange (ETDEWEB)

    Pawliszak, Łukasz; Zgirski, Maciej [Institute of Physics, Polish Academy of Sciences, al.Lotnikow 32/46, PL 02-668 Warszawa (Poland); Tekielak, Maria [Faculty of Physics, University of Białystok, ul.Lipowa 41, PL 15-424 Białystok (Poland)

    2015-03-15

    Nanospintronic and related research often requires the application of quickly rising magnetic field pulses in the plane of the studied planar structure. We have designed and fabricated sub-millimeter-sized coils capable of delivering pulses of the magnetic field up to ∼500 Oe in the plane of the sample with the rise time of the order of 10 ns. The placement of the sample above the coil allows for easy access to its surface with manipulators or light beams for, e.g., Kerr microscopy. We use the fabricated coil to drive magnetic domain walls in 1 μm wide permalloy wires and measure magnetic domain wall velocity as a function of the applied magnetic field.

  8. Magnetic shielding structure optimization design for wireless power transmission coil

    Science.gov (United States)

    Dai, Zhongyu; Wang, Junhua; Long, Mengjiao; Huang, Hong; Sun, Mingui

    2017-09-01

    In order to improve the performance of the wireless power transmission (WPT) system, a novel design scheme with magnetic shielding structure on the WPT coil is presented in this paper. This new type of shielding structure has great advantages on magnetic flux leakage reduction and magnetic field concentration. On the basis of theoretical calculation of coil magnetic flux linkage and characteristic analysis as well as practical application feasibility consideration, a complete magnetic shielding structure was designed and the whole design procedure was represented in detail. The simulation results show that the coil with the designed shielding structure has the maximum energy transmission efficiency. Compared with the traditional shielding structure, the weight of the new design is significantly decreased by about 41%. Finally, according to the designed shielding structure, the corresponding experiment platform is built to verify the correctness and superiority of the proposed scheme.

  9. Magnetic Barkhausen noise measurement by resonant coil method

    Energy Technology Data Exchange (ETDEWEB)

    Capo-Sanchez, J. [Departamento de Fisica, Facultad de Ciencias Naturales, Universidad de Oriente, Av. Patricio Lumumba s/n, 90500 Santiago de Cuba (Cuba)], E-mail: jcapo@usp.br; Padovese, L. [Departamento de Engenharia Mecanica, Escola Politecnica, Universidade de Sao Paulo, Av. Prof. Mello Moraes, 2231, 05508-900 Sao Paulo (Brazil)

    2009-09-15

    This paper describes a powerful new technique for nondestructive evaluation of ferromagnetic material. A method has been developed for measuring magnetic Barkhausen signals under different coil resonance frequencies. The measurements allow one to establish the behavior relating the power spectral density maximum and the resonant coil frequency. Time-frequency analysis of Barkhausen signals puts in evidence the tuning regions for each coil, and allows clear identification of each contribution to the Barkhausen signal spectrum. This concept was used in order to evaluate the relation between the degree of plastic deformation in carbon steel samples, and the power spectral density maximum at different resonance frequencies. This result also makes it possible to the selectively modify measurement sensibility to the magnetic Barkhausen signal by using different resonance frequencies.

  10. Physics design of a saddle coil system for TCV

    Energy Technology Data Exchange (ETDEWEB)

    Rossel, J.X., E-mail: jonathan.rossel@epfl.ch; Moret, J.-M.; Martin, Y.; Pochon, G.

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer The design of a saddle coil system for TCV is presented. Black-Right-Pointing-Pointer The system is designed for ELM control, error field correction and vertical control. Black-Right-Pointing-Pointer The issue of optimal design determination is addressed. Black-Right-Pointing-Pointer Electrical properties in the presence of a conducting wall are quantified. Black-Right-Pointing-Pointer Coil heating due to Joule effect and impact of plasma disruptions are considered. - Abstract: The upgrade project for TCV (Tokamak a Configuration Variable) includes the installation of a set of saddle coils, namely the saddle coil system (SCS), located and powered such as to create a helical magnetic perturbation. Using independent power supplies, the toroidal periodicity of this perturbation is tunable, allowing simultaneously edge localized modes (ELM) control through resonant magnetic perturbation (RMP), error field correction and vertical control. Other experimental applications, like resistive wall mode and rotation control, are also in view. In this article, the adequacy of two SCS designs, an in-vessel one and an ex-vessel one, is assessed with respect to the desired experimental applications. The current requirements and the system performances are also characterized. The conducting vessel wall is accounted for in a model used to determine the coupled response functions of the SCS, the screening of the magnetic perturbation by the wall, the induced voltages and currents during a plasma disruption and the maximal magnetic forces exerted on the SCS. A scaling of the SCS parameters with the number of coil turns is presented and the issue of coil heating and cooling is discussed.

  11. Planar gradient coil design by scaling the spatial frequencies of minimum-inductance current density.

    Science.gov (United States)

    Lee, S Y; Park, B S; Yi, J H; Yi, W

    1997-11-01

    Gradient coil inductance has been remarkably reduced by the minimum-inductance design technique, which minimizes the magnetic energy stored by the gradient coil. The planar gradient coil designed by this technique, however, often has poor magnetic field linearity. Scaling the spatial frequencies of the current density function derived by this method, the magnetic field linearity of the planar gradient coil can be greatly improved with a small sacrifice of gradient coil inductance. A figure of merit of the planar gradient coil has been found to be improved by scaling the spatial frequencies.

  12. Practical aspects of 13C surface receive coils with active decoupling and tuning circuit

    DEFF Research Database (Denmark)

    Nilsson, Daniel; Mohr, Johan Jacob; Zhurbenko, Vitaliy

    2012-01-01

    Magnetic Resonance Imaging (MRI) of nuclei other than 1H (e.g. 13C) allows for characterisation of metabolic processes. Imaging of such nuclei, however, requires development of sensitive MRI coils. This paper describes the design of surface receive coils for 13C imaging in small animals. The design...... is based on application-specified coil profile and includes impedance matching and balancing circuits. Active decoupling is implemented in order to minimize the influence of the receiving coil on the homogeneity of the transmit-coil field. Measurement results for a coil prototype are presented, including...

  13. Coil End Parts Development Using BEND and Design for MQXF by LARP

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Miao [Fermilab; Ambrosio, G. [Fermilab; Bermudez, S. Izquierdo [CERN; Bossert, R. [Fermilab; Ferracin, P. [CERN; Krave, S. [Fermilab

    2016-09-06

    End parts are critical components for saddle-shaped coils. They have a structural function where the cables are deformed in order to cross over the magnet aperture. Based on the previous design of the US LARP program for 90 mm aperture quadrupoles (TQ/LQ) and 120 mm aperture quadrupoles (HQ/LHQ) using BEND, the coil ends of the low-β quadruples (MQXF) for the HiLumi LHC upgrade were developed. This paper shows the design of the MQXF coil ends, the analysis of the coil ends during the coil fabrication, the autopsy analysis of the coil ends and the feedback to BEND parameters.

  14. Design, Analysis, Prototyping, and Experimental Evaluation of an Efficient Double Coil Magnetorheological Valve

    Directory of Open Access Journals (Sweden)

    Guoliang Hu

    2014-05-01

    Full Text Available A double coil magnetorheological (MR valve with an outer annular resistance gap was designed and prototyped. The finite element modeling and analysis of double coil MR valve were carried out using ANSYS/Emag software, and the optimal magnetic field distribution and magnetic flux density of the double coil MR valve were achieved. The mechanism of the pressure drop was studied by building a mathematical model of pressure drop in the double coil MR valve. The proposed double coil MR valve was prototyped and its performance was experimentally evaluated. The new MR valve design has improved the efficiency of double coil MR valve significantly.

  15. Coil End Parts Development Using BEND and Design for MQXF by LARP

    CERN Document Server

    Yu, Miao; Izquierdo Bermudez, S; Bossert, R; Ferracin, P; Krave, S

    2016-01-01

    End parts are critical components for saddle-shaped coils. They have a structural function where the cables are deformed in order to cross over the magnet aperture. Based on the previous design of the US LARP program for 90 mm aperture quadrupoles (TQ/LQ) and 120 mm aperture quadrupoles (HQ/LHQ) using BEND, the coil ends of the low-β quadruples (MQXF) for the HiLumi LHC upgrade were developed. This paper shows the design of the MQXF coil ends, the analysis of the coil ends during the coil fabrication, the autopsy analysis of the coil ends and the feedback to BEND parameters.

  16. Modeling of Lossy Inductance in Moving-Coil Loudspeakers

    DEFF Research Database (Denmark)

    Kong, Xiao-Peng; Agerkvist, Finn T.; Zeng, Xin-Wu

    2015-01-01

    The electrical impedance of moving-coil loudspeakers is dominated by the lossy inductance in high frequency range. Using the equivalent electrical circuit method, a new model for the lossy inductance based on separate functions for the magnitude and phase of the impedance is presented. The electr......The electrical impedance of moving-coil loudspeakers is dominated by the lossy inductance in high frequency range. Using the equivalent electrical circuit method, a new model for the lossy inductance based on separate functions for the magnitude and phase of the impedance is presented...

  17. Stabilization of the vertical instability by non-axisymmetric coils

    Science.gov (United States)

    Turnbull, A. D.; Reiman, A. H.; Lao, L. L.; Cooper, W. A.; Ferraro, N. M.; Buttery, R. J.

    2016-08-01

    In a published Physical Review Letter (Reiman 2007 Phys. Rev. Lett. 99 135007), it was shown that axisymmetric (or vertical) stability can be improved by placing a set of parallelogram coils above and below the plasma oriented at an angle to the constant toroidal planes. The physics of this stabilization can be understood as providing an effective additional positive stability index. The original work was based on a simplified model of a straight tokamak and is not straightforwardly applicable to a finite aspect ratio, strongly shaped plasma such as in DIII-D. Numerical calculations were performed in a real DIII-D -like configuration to provide a proof of principal that 3-D fields can, in fact raise the elongation limits as predicted. A four field period trapezioid-shaped coil set was developed in toroidal geometry and 3D equilibria were computed using trapezium coil currents of 10 kA , 100 kA , and 500 kA . The ideal magnetohydrodynamics growth rates were computed as a function of the conformal wall position for the n = 0 symmetry-preserving family. The results show an insignificant relative improvement in the stabilizing wall location for the two lower coil current cases, of the order of 10-3 and less. In contrast, the marginal wall position is increased by 7% as the coil current is increased to 500 kA , confirming the main prediction from the original study in a real geometry case. In DIII-D the shift in marginal wall position of 7% would correspond to being able to move the existing wall outward by 5 to 10 cm. While the predicted effect on the axisymmetric stability is real, it appears to require higher coil currents than could be provided in an upgrade to existing facilities. Additional optimization over the pitch of the coils, the number of field periods and the coil positions, as well as plasma parameters, such as the internal inductivity {{\\ell}\\text{i}} , β , and {{q}95} would mitigate this but seem unlikely to change the conclusion.

  18. Multi-turn, printed surface coil inductance, and Q optimization.

    Science.gov (United States)

    Raad, A; Kan, S

    1993-03-01

    Wheeler's empirical inductance formula for a multi-turn, close-wound flat coil shows that the maximum inductance for a given length of wire occurs when the outer to inner radius ratios is equal to 15/7. A similar expression is proposed for a flat, printed spiral for surface coil antenna design by modifying one of the coefficients in Wheeler's formula. Measured inductance is in good agreement with this new formula and the optimum radius ratio for maximum inductance or Q is now of the order of 9/5.

  19. Impact response by a foamlike forest of coiled carbon nanotubes

    OpenAIRE

    Daraio, Chiara; Nesterenko, Vitali F.; Jin, Sungho; Wang, Wei; Rao, Apparao M

    2006-01-01

    We studied the dynamic response of a foamlike forest of coiled carbon nanotubes under high strain rate deformation using a simple drop-ball test. The method is based on measuring the dynamic force between the ball and the foam on the substrate during the stages of penetration and restitution. The analysis of the forest’s morphology after impact has shown no trace of plastic deformation and a full recovery of the foamlike layer of coiled carbon nanotubes under various impact velocities. The co...

  20. Transcranial magnetic stimulation: Improved coil design for deep brain investigation

    Science.gov (United States)

    Crowther, L. J.; Marketos, P.; Williams, P. I.; Melikhov, Y.; Jiles, D. C.; Starzewski, J. H.

    2011-04-01

    This paper reports on a design for a coil for transcranial magnetic stimulation. The design shows potential for improving the penetration depth of the magnetic field, allowing stimulation of subcortical structures within the brain. The magnetic and induced electric fields in the human head have been calculated with finite element electromagnetic modeling software and compared with empirical measurements. Results show that the coil design used gives improved penetration depth, but also indicates the likelihood of stimulation of additional tissue resulting from the spatial distribution of the magnetic field.

  1. Characterization of closed nickel-titanium orthodontic coil springs

    Energy Technology Data Exchange (ETDEWEB)

    Langeron, T. [Rene Descartes Univ., Paris V, Pontoise (France). Faculte de Chirurgie Dentaire; Filleul, M.P. [Rene Descartes Univ., Paris V, Pontoise (France). Faculte de Chirurgie Dentaire; ENSCP, Paris (France). Lab. de Metallurgie Structurale; Humbeeck, J. van [Katholieke Univ. Leuven, Heverlee (Belgium). Faculteit Toegepaste Wetenschappen, Metaalkunde en Toegepaste Materialkund

    2001-11-01

    Nickel-titanium orthodontic coil springs are used to move teeth with low forces and slow deactivation. The present paper provides data on transformation temperatures and on load-deflection rate at buccal temperature of closed Nickel-Titanium coil springs available on the market from ORMCO {sup trademark} and GAC {sup trademark}. All the springs exhibited superelasticity but their properties were not stable in the range of buccal temperatures and varied not only from one manufacturer to the other but they also varied from one batch to the other of each supplier. The need for more stability is stressed. (orig.)

  2. Coil end design for the SSC collider dipole magnet

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, J.; Bartlett, N.; Bossert, R.; Carson, J.; Konc, J.; Lee, G. [Fermi National Accelerator Lab., Batavia, IL (United States); Cook, J. [Argonne National Lab., IL (United States); Caspi, S. [Lawrence Berkeley Lab., CA (United States); Gordon, M.; Nobrega, F. [Superconducting Super Collider Lab., Dallas, TX (United States)

    1991-07-01

    This paper describes the design of the coil end for the 50mm aperture SSC collider dipole magnets built at Fermilab. The cable paths are determined from both magnetic and mechanical considerations. The end spacers are designed using the developable surface, grouped end approach, which allows the analysis of strain energy within the conductor groups. Techniques for strain energy minimization are presented and the behavior of individual conductors within a group is analyzed. The relationship between optimization of magnetic and mechanical variables is discussed. Requirements of manufacturing and inspection of coil end parts are outlined. 7 refs.

  3. Ventriculoperitoneal shunt migration and coiling: A report of two cases

    Directory of Open Access Journals (Sweden)

    Shahram Shahsavaran

    2012-01-01

    Full Text Available Migration of the proximal and distal catheters of the ventriculoperitoneal shunt is a very rare event. Here, we report two infants with hydrocephalus and ventriculoperitoneal shunt who presented later with shunt coiling and migration. The first infant was admitted with scalp swelling around proximal incision 3 months after shunt insertion and migration and coiling of both ventricular and peritoneal catheters occurred under the scalp at that point. The second patient was referred 1 month after shunting with tense fontanel and vomiting. New brain imaging confirmed the whole shunt inside both lateral ventricles. The possible mechanisms causing this very uncommon complication and the management are explained.

  4. SERPENTINE COIL TOPOLOGY FOR BNL DIRECT WIND SUPERCONDUCTING MAGNETS.

    Energy Technology Data Exchange (ETDEWEB)

    PARKER, B.; ESCALLIER, J.

    2005-05-16

    Serpentine winding, a recent innovation developed at BNL for direct winding superconducting magnets, allows winding a coil layer of arbitrary multipolarity in one continuous winding process and greatly simplifies magnet design and production compared to the planar patterns used before. Serpentine windings were used for the BEPC-II Upgrade and JPARC magnets and are proposed to make compact final focus magnets for the EC. Serpentine patterns exhibit a direct connection between 2D body harmonics and harmonics derived from the integral fields. Straightforward 2D optimization yields good integral field quality with uniformly spaced (natural) coil ends. This and other surprising features of Serpentine windings are addressed in this paper.

  5. Optimal configuration of receiving coils of SQUID-magnetometer

    CERN Document Server

    Ishikaev, S M

    2002-01-01

    Paper describes a SQUID-magnetometer receiving system based on the second order symmetric gradiometer. Four series connected coils of a superconducting transformer consisting of one niobium-titanium wire turn are cemented onto dewar outside. Due to signal compensation in all coils the given receiving system is unsusceptible to signal from specimen holder and it improves measurement accuracy. Using the described magnetometer one managed to observe abrupt changes of magnetization curves of a 100 x 100 cell square superconducting grid with the Josephson tunnel transitions

  6. Unruptured Basilar Tip Aneurysm with Internal Septation: Coiling Implications?

    Directory of Open Access Journals (Sweden)

    Ayman Khalil

    2016-01-01

    Full Text Available An internal septum within a basilar artery aneurysm is an infrequent anomaly and is very rarely reported in the literature. We report a 62-year-old lady that was incidentally diagnosed with basilar tip aneurysm. Further imaging with magnetic resonance imaging (MRI revealed internal septation within this aneurysm which was later confirmed with digital subtraction angiography (DSA. She underwent coil embolisation, which involved technical manipulation of the microcatheter and the balloon to enable coiling of each separate aneurysm compartment. We present this case to illustrate the effect of this anatomical variation on the selection of endovascular treatment strategy.

  7. Optimization of Moving Coil Actuators for Digital Displacement Machines

    DEFF Research Database (Denmark)

    Nørgård, Christian; Bech, Michael Møller; Roemer, Daniel Beck;

    2016-01-01

    This paper focuses on deriving an optimal moving coil actuator design, used as force pro-ducing element in hydraulic on/off valves for Digital Displacement machines. Different moving coil actuator geometry topologies (permanent magnet placement and magnetiza-tion direction) are optimized...... for actuating annular seat valves in a digital displacement machine. The optimization objectives are to the minimize the actuator power, the valve flow losses and the height of the actuator. Evaluation of the objective function involves static finite element simulation and simulation of an entire operation...

  8. Transcatheter Coil Embolization of an Arc of Buhler Aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Su Jin; Lim, Nam Yeul; Choi, Soo Jin Nah; Kim, Jae Kyu; Jeong, Yong Yeon; Kang, Heoung Keun [Chonnam National University Hospital, Gwangju (Korea, Republic of); Jang, Nam Kyu [Hwasun Chonnam National University Hospital, Hwasun (Korea, Republic of)

    2008-07-15

    We report the findings of a patient with an asymptomatic Arc of Buhler (AOB) aneurysm, which was successfully treated by transcatheter coil embolization. An abdominal CT and angiography revealed an intact pancreaticoduodenal artery arcade (PDAA) and an anomalous communication between the SMA and celiac axis, termed an AOB. An aneurysm was observed at the origin of the AOB and treated with a transcatheter embolization using coils. A follow-up CT imaging confirmed the total occlusion of the aneurysm with a patent PDAA. The successful results of this treatment suggest that the endovascular therapy of an AOB aneurysm with a celiac axis occlusion and an intact PDAA is feasible and safe.

  9. Synthesis, model and stability of helically coiled carbon nanotubes

    DEFF Research Database (Denmark)

    Fejes, Dora; Raffai, Manuella; Hernadi, Klara

    2013-01-01

    Structural model of helically coiled carbon nanotubes is proposed. It is constructed by means of topological coordinate method. Relaxation and cohesive energy calculation are performed by molecular mechanics, using second-generation bond order potential for hydrocarbons introduced by D. W. Brenner....... Our experiments focused on the production and development of catalysts for the synthesis of helically coiled CNTs (carbon nanotubes). The catalysts were tested in the decomposition of acetylene by CCVD (Catalytic Chemical Vapor Deposition) method. The carbon deposit was imaged by TEM (Transmission...

  10. Dual inductive link coil design for a neural recording system.

    Science.gov (United States)

    Rush, Alexander; Troyk, Philip R

    2011-01-01

    This paper reports an approach to the physical design of the coils used in a dual inductive link to provide two-way wireless communication and power for a neural recording system. The design approach makes use of an analytic model of the link performance in terms of the physical parameters of the link, which allows physical parameters to be iterated on a computer rather than on the bench to find the optimal design within the physical restrictions imposed. In particular, this approach was used to choose the optimal implant data coil sizing to maximize the difference between the contributions of the constructive and destructive paths of the reverse telemetry signal.

  11. Magnetic field sensitivity at 7-T using dual-helmholtz transmit-only coil and 12-channel receive-only bended coil.

    Science.gov (United States)

    Kim, Kyoung-Nam; Ryu, Yeunchul; Seo, Jeung-Hoon; Kim, Young-Bo

    2016-11-01

    The purpose of this study was to combine a dual-Helmholtz (DH) transmit (Tx)-only coil and 12-channel receive (Rx)-only bended phased array (PA) coil to improve the magnetic flux (|B1 |) sensitivity in the superior-to-inferior (S-I) direction during human brain magnetic resonance imaging (MRI) at 7-T. The proposed coil combination was primarily implemented by electromagnetic (EM) simulation and compared with the 16-leg birdcage coil and 8-channel PA coil, which are generally used for the Tx- and Rx-only modes, respectively. The optimal coil combinations for the proposed structure were determined by |B1 | field calculations using the |BT(+) | and |BR(-) | fields, which are respectively the transmit and receive components of the |B1 | field. The coil performance was then evaluated by a bench test and 7-T MRI experiment. The results of the computational calculations indicated that the |BT(+) | field of the DH coil was distributed similarly to that of the 16-leg birdcage coil despite the fewer conducting legs of the former. However, the 12-channel Rx-only bended PA coil had clearly higher |BR(-) | profiles compared to the 8-channel PA coil. The results of the 7-T in vivo experiment showed that the proposed combination of the DH Tx-only coil and 12-channel Rx-only bended PA coil had better |B1 | field homogeneity in the sagittal slice as well as higher |B1 | field sensitivity during human brain MRI compared to an 8-channel Rx-only PA coil. SCANNING 38:515-524, © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  12. Cholera toxin B subunit-five-stranded α-helical coiled-coil fusion protein: "five-to-five" molecular chimera displays robust physicochemical stability.

    Science.gov (United States)

    Arakawa, Takeshi; Harakuni, Tetsuya

    2014-09-03

    To create a physicochemically stable cholera toxin (CT) B subunit (CTB), it was fused to the five-stranded α-helical coiled-coil domain of cartilage oligomeric matrix protein (COMP). The chimeric fusion protein (CTB-COMP) was expressed in Pichia pastoris, predominantly as a pentamer, and retained its affinity for the monosialoganglioside GM1, a natural receptor of CT. The fusion protein displayed thermostability, tolerating the boiling temperature of water for 10min, whereas unfused CTB readily dissociated to its monomers and lost its affinity for GM1. The fusion protein also displayed resistance to strong acid at pHs as low as 0.1, and to the protein denaturant sodium dodecyl sulfate at concentrations up to 10%. Intranasal administration of the fusion protein to mice induced anti-B subunit serum IgG, even after the protein was boiled, whereas unfused CTB showed no thermostable mucosal immunogenicity. This study demonstrates that CTB fused to a pentameric α-helical coiled coil has a novel physicochemical phenotype, which may provide important insight into the molecular design of enterotoxin-B-subunit-based vaccines and vaccine delivery molecules.

  13. Electrochemical wave transmission and rapid coiling movement in tendril of luffa

    Institute of Scientific and Technical Information of China (English)

    杨文定; 娄成后

    1995-01-01

    The tendril of luffa (Luffa officinale),in response to various non-injurious and injuriousstimulations,will first give rise to electrochemical transmission including the action wave,variation wave,andwave complex.It is then followed by rapid coiling movement which appears within 25—30 s after stimulation.The coiling process continues for 10 min or more.When it is over,the tendril begins to uncoil itself.Tendrils pretreated with the narcotic drug,ethyl ether fail to response to stimulation entirely.Specific inhibitorsof microfilament,cytochalasins B and D,and of myosin,N-ethylmaleimide and iodoacetic acid,are both able toprevent the coiling of tendril,without any effect on the electrical wave transmission.Colchicine,known toinhibit microtubule action,is ineffective in preventing coiling.Acetylcholine is able to provoke the tendril coilingdirectly.The effects of drug pretreatments support the proposal that the electrochemical wave transmission elicitedby stimulation is the forerunner for arousing the rapid movement of the sensitive tendril that the actin and myosinare taking part in.Turgor changes in tendril cells are intimately connected with the transmitted and the motoraction of the compact tissues lining along the more sensitive ventral side of the tendril.As the ventral cellsundergo the abrupt contraction and slightly shrink,the dorsal cells become expanded in coiling.Eventually,turgotresumes normal on both sides when uncoiling occurs.

  14. 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

  15. Coiling vs. clipping. Hospital stay and procedure time in intracranial aneurysm treatment

    Energy Technology Data Exchange (ETDEWEB)

    Brunken, Martin; Kehler, U. [Abt. fuer Neurochirurgie, Asklepios-Klinik Altona (Germany); Fiehler, J. [Neuroradiology, Universitaetskrankenhaus Hamburg-Eppendorf (Germany); Leppien, A.; Eckert, B. [Fachbereich Neuroradiologie, Asklepios-Klinik Altona (Germany)

    2009-10-15

    Purpose: evaluation of hospital resource allocation in intracranial aneurysm treatment in a medium-volume neurovascular center. Materials and methods: retrospective data analysis included 653 procedures performed on 598 patients with 667 aneurysms (A) from 1990 to 2004. 515 treatments were carried out in ruptured A (clip: n = 370; coil: n = 145) and 138 procedures in non-ruptured A (clip: n = 51, coil: n = 87). Patient management data included procedure time (min), length of stay in the intensive care unit (days), total length of hospital stay (days), and discharge to home ratio. Results: clinical admission grade (rupt. A: Hunt and Hess grade 1-3: clip: 73% coil: 72%) and clinical outcome at discharge (good neurological outcome/mortality rate: rupt. A: clip: 51.1/13.8% coil: 45.5/10.3% non-rupt. A: 88.2/0% coil: 88.5/1.3%) were similar for both treatment modes. The coil procedure time was found to be significantly shorter (rupt. A: coil: 145 min; clip: 203 min; p < 0.01; non-rupt. A: coil: 164 min, clip: 200 min; p < 0.01). Coiling reduced the length of stay in the ICU (rupt. A: coil: 5.3 d; clip: 6d, p < 0.01; non-rupt. A: coil: 1.5d; clip: 2d; p = 0.21) and coiling significantly reduced the length of hospital stay (rupt. A: coil: 21.4d; clip: 26.8 d, p < 0.01; non-rupt. A: coil: 9.2d; clip: 17.5d; p = 0.01). The discharge to home ratio did not differ (rupt. A: clip: 31.6% coil: 29.7% nonrupt. A: clip: 74.5% coil: 80.5%). Conclusion: in a medium-volume neurovascular center, coiling significantly reduced the procedure time, the stay in the ICU, and the length of hospital stay suggesting favorable resource allocation in endovascular therapy. (orig.)

  16. Mid-Range Coil Array for Magnetic Resonance Imaging of Small Animals

    Science.gov (United States)

    Solis, S. E.; Tomasi, D.; Rodríguez, A. O.

    2008-08-01

    The vast majority of articles on MRI RF coils over the past two decades have focused on large coils, where sample losses dominate, or on micro-coils, where sample and capacitor losses are negligible. Few have addressed the mid-range coils, seen in the majority of small-animal applications, where all the sources of loss are important, for example, mouse brain and body coils from 125 to 750 MHz. We developed a four-saddle coil array for magnetic resonance imaging of small animals. The saddle coil elements in the array were evenly distributed to cover the rat's head. The coil array was tuned to the resonant frequency of 170 MHz. Due to the close proximity of the coil elements, it was necessary to decouple the coil array using nonmagnetic trimmers and, it was operated in the transceiver mode and quadrature-driven. To test the coil array performance at high field, phantom images were acquired with our saddle coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. Ex vivo brain images of a rat were also acquired, and proved the feasibility of the scaled version of a saddle coil array and, its compatibility with standard pulse sequences when used in a high field magnetic resonance imager.

  17. Formulation for a practical implementation of electromagnetic induction coils optimized using stream functions

    Science.gov (United States)

    Reed, Mark A.; Scott, Waymond R.

    2016-05-01

    Continuous-wave (CW) electromagnetic induction (EMI) systems used for subsurface sensing typically employ separate transmit and receive coils placed in close proximity. The closeness of the coils is desirable for both packaging and object pinpointing; however, the coils must have as little mutual coupling as possible. Otherwise, the signal from the transmit coil will couple into the receive coil, making target detection difficult or impossible. Additionally, mineralized soil can be a significant problem when attempting to detect small amounts of metal because the soil effectively couples the transmit and receive coils. Optimization of wire coils to improve their performance is difficult but can be made possible through a stream-function representation and the use of partially convex forms. Examples of such methods have been presented previously, but these methods did not account for certain practical issues with coil implementation. In this paper, the power constraint introduced into the optimization routine is modified so that it does not penalize areas of high current. It does this by representing the coils as plates carrying surface currents and adjusting the sheet resistance to be inversely proportional to the current, which is a good approximation for a wire-wound coil. Example coils are then optimized for minimum mutual coupling, maximum sensitivity, and minimum soil response at a given height with both the earlier, constant sheet resistance and the new representation. The two sets of coils are compared both to each other and other common coil types to show the method's viability.

  18. Development of Computational Models for Coiling Process with the Belt Wrapper

    Science.gov (United States)

    Park, Yonghui; Park, Hyunchul

    2016-10-01

    This study introduces coiling mechanism with the belt wrapper to understand a force equilibrium for successful coiling. By establishing a finite element (FE) model, strips were coiled 2 to 3 rotations by the belt wrapper on the sleeve without coiling tension T, then T was applied to the opposite side of the strips near the pinch roller, and the belt wrapper was removed from the strip coil at the same time. Additionally, analytical model corresponding to FE model was defined by thick and thin cylinder theorems to quantize coiling mechanisms. Especially elasticity of the belt wrapper E [N/m2], coiling tension T [N/m2], and friction coefficient μ were checked on how these variables affect each other, were converted into pressure P [N/m2], and P were used to calculate when the strip coil come untied. For instance, the strip coil came untied when E was lower than 1 × 109 N/m2 corresponding to ( {{{{Pressure}} {{on}} {{outmost}} {{of the belt wrapper}} P_{{o,belt}} }/{{{Pressure} {{on}} {{innermost}} {{of the sleeve}} P_{{i,sleeve}} }} = 0.877} ) . Lastly, radial stress on the outmost of the sleeve σ r,o,sleeve [N/m2] according to E were compared to the previous coiling method with the grooved joint to see how these methods are different. Based on these results, this paper suggests coiling criteria to avoid coiling failure of slip of the strip coil.

  19. A multi-slot surface coil for MRI of dual-rat imaging at 4 T

    Energy Technology Data Exchange (ETDEWEB)

    Solis, S E; Rodriguez, A O [Departamento de Ingenieria Electrica, Universidad Autonoma Metropolitana Iztapalapa, Mexico, DF 09340 (Mexico); Wang, R; Tomasi, D, E-mail: arog@xanum.uam.mx [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2011-06-21

    A slotted surface coil inspired by the hole-and-slot cavity magnetron was developed for magnetic resonance imaging of obese rats at 4 T. Full-wave analysis of the magnetic field was carried out at 170 MHz for both the slotted and circular-shaped coils. The noise figure values of two coils were investigated via the numerical calculation of the quality factors. Fat simulated phantoms to mimic overweight rats were included in the analysis with weights ranging from 300 to 900 g. The noise figures were 1.2 dB for the slotted coil and 2.4 dB for the circular coil when loaded with 600 g of simulated phantom. A slotted surface coil with eight circular slots and a circular coil with similar dimensions were built and operated in the transceiver mode, and their performances were experimentally compared. The imaging tests in phantoms demonstrated that the slotted surface coil has a deeper RF-sensitivity and better field uniformity than the single-loop RF-coil. High quality images of two overweight Zucker rats were acquired simultaneously with the slotted surface coil using standard spin-echo pulse sequences. Experimental results showed that the slotted surface coil outperformed the circular coil for imaging considerably overweight rats. Thus, the slotted surface coil can be a good tool for MRI experiments in rats on a human whole-body 4 T scanner.

  20. A multi-slot surface coil for MRI of dual-rat imaging at 4T

    Energy Technology Data Exchange (ETDEWEB)

    Solis, S.E.; Tomasi, D.; Solis, S.E.; Wang, R.; Tomasi, D.; Rodriguez, A.O.

    2011-07-01

    A slotted surface coil inspired by the hole-and-slot cavity magnetron was developed for magnetic resonance imaging of obese rats at 4 T. Full-wave analysis of the magnetic field was carried out at 170 MHz for both the slotted and circular-shaped coils. The noise figure values of two coils were investigated via the numerical calculation of the quality factors. Fat simulated phantoms to mimic overweight rats were included in the analysis with weights ranging from 300 to 900 g. The noise figures were 1.2 dB for the slotted coil and 2.4 dB for the circular coil when loaded with 600 g of simulated phantom. A slotted surface coil with eight circular slots and a circular coil with similar dimensions were built and operated in the transceiver mode, and their performances were experimentally compared. The imaging tests in phantoms demonstrated that the slotted surface coil has a deeper RF-sensitivity and better field uniformity than the single-loop RF-coil. High quality images of two overweight Zucker rats were acquired simultaneously with the slotted surface coil using standard spin-echo pulse sequences. Experimental results showed that the slotted surface coil outperformed the circular coil for imaging considerably overweight rats. Thus, the slotted surface coil can be a good tool for MRI experiments in rats on a human whole-body 4 T scanner.

  1. Atomic hydrodynamics of DNA: coil-uncoil-coil transitions in a wall-bounded shear flow.

    Science.gov (United States)

    Sandberg, William C; Wang, Guan M

    2008-12-01

    Extensive experimental work on the response of DNA molecules to externally applied forces and on the dynamics of DNA molecules flowing in microchannels and nanochannels has been carried out over the past two decades, however, there has not been available, until now, any atomic-scale means of analyzing nonequilibrium DNA response dynamics. There has not therefore been any way to investigate how the backbone and side-chain atoms along the length of a DNA molecule interact with the molecules and ions of the flowing solvent and with the atoms of passing boundary surfaces. We report here on the application of the nonequilibrium biomolecular dynamics simulation method that we developed [G. M. Wang and W. C. Sandberg, Nanotechnology 18, 4819 (2007)] to analyze, at the atomic interaction force level, the conformational dynamics of short-chain single-stranded DNA molecules in a shear flow near a surface. This is a direct atomic computational analysis of the hydrodynamic interaction between a biomolecule and a flowing solvent. The DNA molecules are observed to exhibit conformational behaviors including coils, hairpin loops, and figure-eight shapes that have neither been previously measured experimentally nor observed computationally, as far as we know. We relate the conformational dynamics to the atomic interaction forces experienced throughout the length of a molecule as it moves in the flowing solvent past the surface boundary. We show that the DNA conformational dynamics is related to the asymmetry in the molecular environment induced by the motion of the surrounding molecules and the atoms of the passing surface. We also show that while the asymmetry in the environment is necessary, it is not sufficient to produce the observed conformational dynamics. A time variation in the asymmetry, due in our case to a shear flow, must also exist. In order to contrast these results with the usual experimental situation of purely diffusive motion in thermal equilibrium we have also

  2. Oncogenic TPM3-ALK activation requires dimerization through the coiled-coil structure of TPM3

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yosuke; Ishikawa, Rie; Sakatani, Toshio [Department of Respiratory Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Ichinose, Junji [Department of Cardiothoracic Surgery, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sunohara, Mitsuhiro; Watanabe, Kousuke; Kage, Hidenori [Department of Respiratory Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Nakajima, Jun [Department of Cardiothoracic Surgery, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Nagase, Takahide; Ohishi, Nobuya [Department of Respiratory Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Takai, Daiya, E-mail: dtakai-ind@umin.ac.jp [Department of Respiratory Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Department of Clinical Laboratory, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2015-02-13

    Inflammatory myofibroblastic tumor (IMT) is a mesenchymal tumor that can arise from anywhere in the body. Anaplastic lymphoma kinase (ALK) gene rearrangements, most often resulting in the tropomyosin 3 (TPM3)-ALK fusion gene, are the main causes of IMT. However, the mechanism of malignant transformation in IMT has yet to be elucidated. The purpose of this study was to clarify the role of the TPM3 region in the transformation of IMT via TPM3-ALK. Lentivirus vectors containing a TPM3-ALK fusion gene lacking various lengths of TPM3 were constructed and expressed in HEK293T and NIH3T3 cell lines. Focus formation assay revealed loss of contact inhibition in NIH3T3 cells transfected with full-length TPM3-ALK, but not with ALK alone. Blue-native polyacrylamide gel electrophoresis (BN-PAGE) revealed that TPM3-ALK dimerization increased in proportion to the length of TPM3. Western blot showed phosphorylation of ALK, ERK1/2, and STAT3 in HEK293T cells transfected with TPM3-ALK. Thus, the coiled-coil structure of TPM3 contributes to the transforming ability of the TPM3-ALK fusion protein, and longer TPM3 region leads to higher dimer formation. - Highlights: • TPM3-ALK fusion protein dimerizes through the coiled-coil structure of TPM3. • Longer coiled-coil structure of TPM3 leads to higher TPM3-ALK dimer formation. • Presence of TPM3-ALK dimer leads to ALK, STAT3, and ERK1/2 phosphorylation. • Presence of TPM3-ALK leads to loss of contact inhibition. • BN-PAGE is a simple technique for visualizing oncogenic dimerization.

  3. Septin phosphorylation and coiled-coil domains function in cell and septin ring morphology in the filamentous fungus Ashbya gossypii.

    Science.gov (United States)

    Meseroll, Rebecca A; Occhipinti, Patricia; Gladfelter, Amy S

    2013-02-01

    Septins are a class of GTP-binding proteins conserved throughout many eukaryotes. Individual septin subunits associate with one another and assemble into heteromeric complexes that form filaments and higher-order structures in vivo. The mechanisms underlying the assembly and maintenance of higher-order structures in cells remain poorly understood. Septins in several organisms have been shown to be phosphorylated, although precisely how septin phosphorylation may be contributing to the formation of high-order septin structures is unknown. Four of the five septins expressed in the filamentous fungus, Ashbya gossypii, are phosphorylated, and we demonstrate here the diverse roles of these phosphorylation sites in septin ring formation and septin dynamics, as well as cell morphology and viability. Intriguingly, the alteration of specific sites in Cdc3p and Cdc11p leads to a complete loss of higher-order septin structures, implicating septin phosphorylation as a regulator of septin structure formation. Introducing phosphomimetic point mutations to specific sites in Cdc12p and Shs1p causes cell lethality, highlighting the importance of normal septin modification in overall cell function and health. In addition to discovering roles for phosphorylation, we also present diverse functions for conserved septin domains in the formation of septin higher-order structure. We previously showed the requirement for the Shs1p coiled-coil domain in limiting septin ring size and reveal here that, in contrast to Shs1p, the coiled-coil domains of Cdc11p and Cdc12p are required for septin ring formation. Our results as a whole reveal novel roles for septin phosphorylation and coiled-coil domains in regulating septin structure and function.

  4. [Importance of an automatic measurement base on the first coil diameter in regard to coil embolization of a cerebral aneurysm].

    Science.gov (United States)

    Kuriyama, Takumi; Furukawa, Hajime; Shimizu, Keiji; Oonishi, Kumiko; Sakai, Shinji; Imamura, Hirotoshi; Sakai, Chiaki; Sakai, Nobuyuki

    2012-01-01

    We compared the accuracy in evaluating an unrapture aneurysm between NV and 3D-DSA. In vitro, we evaluated the accuracy in calculating the volume of the Aneurysm model. We compared the diameter of the first coil and estimated the diameter of the Aneurysm. The Aneurysm size calculated by NV resembled the first coil more than the size measured by 3D-DSA. In clinical cases, the measurement of NV is objective; the measurement of 3D-DSA, however, is subjective by person. NV has an automatic measurement that is useful for clinical cases.

  5. Crystal structure of tetranectin, a trimeric plasminogen-binding protein with an alpha-helical coiled coil

    DEFF Research Database (Denmark)

    Nielsen, B B; Kastrup, J S; Rasmussen, H

    1997-01-01

    Tetranectin is a plasminogen kringle 4-binding protein. The crystal structure has been determined at 2.8 A resolution using molecular replacement. Human tetranectin is a homotrimer forming a triple alpha-helical coiled coil. Each monomer consists of a carbohydrate recognition domain (CRD) connected...... to a long alpha-helix. Tetranectin has been classified in a distinct group of the C-type lectin superfamily but has structural similarity to the proteins in the group of collectins. Tetranectin has three intramolecular disulfide bridges. Two of these are conserved in the C-type lectin superfamily, whereas...

  6. RWM Feedback Stabilization with the New Internal Coil (I-Coil)

    Science.gov (United States)

    Okabayashi, M.; Chance, M. S.; Bialek, J.; Garofalo, A. M.; Navratil, G. A.; Reimerdes, H.; Chu, M. S.; Jackson, G. L.; Jensen, T. H.; La Haye, R. J.; Scoville, J. T.; Strait, E. J.; Jayakumar, R. J.; Edgell, D. H.

    2003-10-01

    RWM stabilization by rotational viscosity has been observed as a quite robust approach for achieving the stable n=1 kink plasma beta up to ideal wall limit. For less rotation configurations, such as expected in burning plasma, it is highly desirable to establish the same level of robust RWM stabilizing system. VALEN code predicts that newly installed I-coil with upgraded digital control system can provide RWM stabilization up to the ideal wall beta limit using direct feedback even without plasma rotation. A major advantage of new system is the adjustability of poloidal m-component to the plasma eigen mode. To demonstrate the effectiveness of direct feedback stabilization in the highly rotating NBI heated plasma, the plasma rotation was reduced either by resonant n=1 braking or non-resonant n=3 braking. It was found that the feedback can sustain the plasma above no-wall limit even when the rotation outside q>2 was reduced to nearly zero. Issues related to the feedback performance improvement will be discussed.

  7. Evaluation of the heat transfer performance of helical coils of non-circular tubes

    Institute of Scientific and Technical Information of China (English)

    Jundika C.KURNIA; Agus P.SASMITO; Arun S.MUJUMDAR

    2011-01-01

    This study addresses heat transfer performance of various configurations of coiled non-circular tubes, e. g. , in-plane spiral ducts, helical spiral ducts, and conical spiral ducts. The laminar flow of a Newtonian fluid in helical coils made of square cross section tubes is simulated using the computational fluid dynamic approach. The effects of tube Reynolds number, fluid Prandtl number, coil diameter, etc. , are quantified and discussed. Both constant wall temperature and constant heat flux conditions are simulated. The effect of in-plane coil versus a cylindrical design of constant coil, as well as a conical coil design is discussed. Results are compared with those for a straight square tube of the same length as that used to form the coils. Advantages and limitations of using coiled tubes are discussed in light of the numerical results.

  8. The reciprocity between coiling direction and dimorphic reproduction in benthic foraminifera

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.; Khare, N.

    There are various opinions as to what parameter influences the coiling directions in foraminifera. "Do microspheric and megalospheric generations have different coiling ratios?" is an unanswered question in foraminiferal studies. Per view of this...

  9. High-Tc Superconductor Detection Coils for a Magnetic Resonance System

    Institute of Scientific and Technical Information of China (English)

    康琳; 吴培亨; 潘俊; 蔡卫星; 杨森祖; 曹春海

    2002-01-01

    Considering that in a magnetic resonance system, if the detection coil contributes dominantly to the system noise, the performance of the whole system can certainly be improved by switching to a detection coil made of a high-temperature superconductor, and using YBa2Cu3O7 thinfilms on 25 × 25 mm2 LaAIO3 substrates, we have prepared two kinds of detection coils: single-coil and two-coil. Encouragingly, their quality factors are measured to be Q > 2500 for two-coil (at 22.566MHz and 77K) and Q > 5500 for single-coil (at 92.3MHz and 77K),respectively. Here, we describe the details of the design, fabrication and testing of the coils.

  10. Lightweight Design of an HTS Coil for the VASIMR Experiment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Tai-Yang Research of Delaware proposes to design and fabricate an HTS double-pancake coil in support of the VASIMR experiment. The proposed HTS coil will implement...

  11. Comparing Saddle, Slotted-tube and Parallel-plate Coils for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Nespor D.

    2014-06-01

    Full Text Available The paper is concerned with a comparison of the properties of RF coils of three configurations for MRI measurements on small animals. In comparison with the classical saddle coil the proposed modification of slotted-tube coil exhibits identical homogeneity of B1 field in a larger space. The parallel-plate coil has a satisfactory homogeneity of B1 field over the whole internal space. The signal-to-noise ratio measured for all three coils is roughly the same and is given by the magnitude of RF pre-amplifier noise. As the slotted-tube and parallel-plate coils have a lower inductance compared with the saddle coil, they can be tuned to resonance on the 200 MHz frequency even at larger dimensions. The results show that the parallel-plate coil has very good properties for the measurement of small animals.

  12. A method for estimating tokamak poloidal field coil currents which incorporates engineering constraints

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, W.A.

    1990-05-01

    This thesis describes the development of a design tool for the poloidal field magnet system of a tokamak. Specifically, an existing program for determining the poloidal field coil currents has been modified to: support the general case of asymmetric equilibria and coil sets, determine the coil currents subject to constraints on the maximum values of those currents, and determine the coil currents subject to limits on the forces those coils may carry. The equations representing the current limits and coil force limits are derived and an algorithm based on Newton's method is developed to determine a set of coil currents which satisfies those limits. The resulting program allows the designer to quickly determine whether or not a given coil set is capable of supporting a given equilibrium. 25 refs.

  13. Coil optimization for electromagnetic levitation using a genetic like algorithm

    Science.gov (United States)

    Royer, Z. L.; Tackes, C.; LeSar, R.; Napolitano, R. E.

    2013-06-01

    The technique of electromagnetic levitation (EML) provides a means for thermally processing an electrically conductive specimen in a containerless manner. For the investigation of metallic liquids and related melting or freezing transformations, the elimination of substrate-induced nucleation affords access to much higher undercooling than otherwise attainable. With heating and levitation both arising from the currents induced by the coil, the performance of any EML system depends on controlling the balance between lifting forces and heating effects, as influenced by the levitation coil geometry. In this work, a genetic algorithm is developed and utilized to optimize the design of electromagnetic levitation coils. The optimization is targeted specifically to reduce the steady-state temperature of the stably levitated metallic specimen. Reductions in temperature of nominally 70 K relative to that obtained with the initial design are achieved through coil optimization, and the results are compared with experiments for aluminum. Additionally, the optimization method is shown to be robust, generating a small range of converged results from a variety of initial starting conditions. While our optimization criterion was set to achieve the lowest possible sample temperature, the method is general and can be used to optimize for other criteria as well.

  14. Design and development of coil casing MRF brake system

    Directory of Open Access Journals (Sweden)

    Siti Lydia R.

    2017-01-01

    Full Text Available Nowadays magneto-rheological brakes has been introduce to overcome the drawback of conventional braking such as bulky, leakage and late build up pressure. Magnetic field is a main parameter need to be maximized in order to increase the efficiency of the brake. In MRF brake system the magnetic field directly affected by coil casing shapes. This paper focused on the study of the effect of coil casing shapes to the magnetic field distribution in MR brake. Finite Element Method will be used to analyze the magnetic field distribution produced by the coil. Five coils shape that different angle from 50° to 90° used in this study. As the result magnetic field was change quadratically by increasing the angle size. The best angle is between 60° to 70°. The peak value is at 70°. If more than that the magnetic field will drop. The significant of this study is to get the most efficient angle for the electromagnet casing for the MR brakes.

  15. Typical application of Rogowski coils in inspection of electrobath

    Institute of Scientific and Technical Information of China (English)

    郭红; 贾正春

    2004-01-01

    During the aluminum electrolytic roasting process, each component of the electrobath of aluminum performs unsteadily when the electrolytic bath is in the pre-roasting stage. It is important to monitor the currents of the anodes and the cathodes of the aluminum electrobath at regular intervals. Both practice and investigation indicate that Rogowski coil can be adopted to measure heavy direct current of the anodes and the cathodes of the aluminum electrobath. The paper not only introduces the typical application of the Rogowski coil to inspect the state of aluminum electrobath in the roasting process, but also analyzes the principles of the coil sensor including its dynamic properties and some important measurement results respectively. The optimal parameters of the coil can be simulated by means of an advanced simulation tool: simulink tools based on MATLAB soft environment. Based on the gathered current data, an even-current coefficient has been introduced, and the current curve can be drawn. Since they are applied in AL-Electrolyzing, it is possible to distinguish the anode of which the current is not evenly distributed, and to take adjusting measures over a period of time to ensure that the current is evenly distributed.

  16. Coil size oscillatory packing in polymer solutions near a surface

    NARCIS (Netherlands)

    Gucht, van der J.; Besseling, N.A.M.; Male, van J.; Cohen Stuart, M.A.

    2000-01-01

    The theory developed by Scheutjens and Fleer to describe polymer adsorption and depletion is used to calculate the density profile of nonadsorbing polymers near a surface. The theory predicts damped oscillations in the segment density profile with a wavelength of about the coil size. As a consequenc

  17. Optimum Construction of Heating Coil for Domestic Induction Cooker

    Science.gov (United States)

    Sinha, Dola; Bandyopadhyay, Atanu; Sadhu, Pradip Kumar; Pal, Nitai

    2010-10-01

    The design and optimization of the parameters of heating coil is very important for the analytical analysis of high frequency inverter fed induction cooker. Moreover, accurate prediction of high frequency winding loss (i.e., losses due to skin and proximity effects) is necessary as the induction cooker used in power electronics applications. At high frequency current penetration in the induction coil circuit is very difficult for conducting wire due to skin-effect. To eradicate the skin effect heating coil is made up of bundle conductor i.e., litz wire. In this paper inductances and AC resistances of a litz-wire are calculated and optimized by considering the input parameters like wire type, shape, number of strand, number of spiral turn, number of twist per feet of heating coil and operating frequency. A high frequency half bridge series resonant mirror inverter circuit is used in this paper and taking the optimum values of inductance and ac resistance the circuit is simulated through PSPICE simulations. It has been noticed that the results are feasible enough for real implementation.

  18. Equilibrium modeling of the TFCX poloidal field coil system

    Energy Technology Data Exchange (ETDEWEB)

    Strickler, D.J.; Miller, J.B.; Rothe, K.E.; Peng, Y.K.M.

    1984-04-01

    The Toroidal Fusion Core Experiment (TFCX) isproposed to be an ignition device with a low safety factor (q approx. = 2.0), rf or rf-assisted startup, long inductive burn pulse (approx. 300 s), and an elongated plasma cross section (kappa = 1.6) with moderate triangularity (delta = 0.3). System trade studies have been carried out to assist in choosing an appropriate candidate for TFCX conceptual design. This report describes an important element in these system studies - the magnetohydrodynamic (MHD) equilibrium modeling of the TFCX poloidal field (PF) coil system and its impact on the choice of machine size. Reference design points for the all-super-conducting toroidal field (TF) coil (TFCX-S) and hybrid (TFCX-H) options are presented that satisfy given PF system criteria, including volt-second requirements during burn, mechanical configuration constraints, maximum field constraints at the superconducting PF coils, and plasma shape parameters. Poloidal coil current waveforms for the TFCX-S and TFCX-H reference designs consistent with the equilibrium requirements of the plasma startup, heating, and burn phases of a typical discharge scenario are calculated. Finally, a possible option for quasi-steady-state operation is discussed.

  19. An improved trap design for decoupling multinuclear RF coils.

    Science.gov (United States)

    Meyerspeer, Martin; Serés Roig, Eulalia; Gruetter, Rolf; Magill, Arthur W

    2014-08-01

    Multinuclear magnetic resonance spectroscopy and imaging require a radiofrequency probe capable of transmitting and receiving at the proton and non-proton frequencies. To minimize coupling between probe elements tuned to different frequencies, LC (inductor-capacitor) traps blocking current at the (1)H frequency can be inserted in non-proton elements. This work compares LC traps with LCC traps, a modified design incorporating an additional capacitor, enabling control of the trap reactance at the low frequency while maintaining (1)H blocking. Losses introduced by both types of trap were analysed using circuit models. Radiofrequency coils incorporating a series of LC and LCC traps were then built and evaluated at the bench. LCC trap performance was then confirmed using (1)H and (13)C measurements in a 7T human scanner. LC and LCC traps both effectively block interaction between non-proton and proton coils at the proton frequency. LCC traps were found to introduce a sensitivity reduction of 5±2%, which was less than half of that caused by LC traps. Sensitivity of non-proton coils is critical. The improved trap design, incorporating one extra capacitor, significantly reduces losses introduced by the trap in the non-proton coil. Copyright © 2013 Wiley Periodicals, Inc.

  20. Modelling of a Coil Steam Generator for CSP applications

    DEFF Research Database (Denmark)

    Pelagotti, Leonardo; Sørensen, Kim; Condra, Thomas Joseph;

    2014-01-01

    The project investigates a new design for a CSP plant steam generation system, the Coil Steam Generator (CSG). This system allows faster start-ups and therefore higher daily energy production from the Sun. An analytical thermodynamic simulation model of the evaporator and a mechanical analysis...

  1. Speed Control and Coiling Temperature Control of Strip

    Institute of Scientific and Technical Information of China (English)

    CAI Xiao-hui; ZHANG Dian-hua; WANG Guo-dong; LIU Xiang-hua; FAN Lei

    2004-01-01

    Considering the strip speed during controlled laminar cooling on Baosteel 1580 hot strip mill in China, the influence of strip speed fluctuation on coiling temperature control for the tail and "neck" of the strip was analyzed. The optimization strategies were put forward and proved effective in operation.

  2. Insulating process for HT-7U central solenoid model coils

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The HT-7U superconducting Tokamak is a whole superconducting magnetically confined fusion device. The insulating system of its central solenoid coils is critical to its properties. In this paper the forming of the insulating system and the vacuum-pressure-impregnating (VPI) are introduced, and the whole insulating process is verified under the superconducting experiment condition.

  3. Flux Redux: The Spinning Coil Comes around Again

    Science.gov (United States)

    Lund, Daniel; Dietz, Eric; Zou, Xueli; Ard, Christopher; Lee, Jaydie; Kaneshiro, Chris; Blanton, Robert; Sun, Steven

    2017-01-01

    An essential laboratory exercise for our lower-division electromagnetism course involves the measurement of Earth's local magnetic field from the emf induced in a rotating coil of wire. Although many methods exist for the measurement of Earth's field, this one gives our students some practical experience with Faraday's law. The apparatus we had…

  4. Coil embolization of an anastomotic leak after ascending aorta replacement

    DEFF Research Database (Denmark)

    Nørgaard, Anders; Andersen, Lars Ib; Haahr, P.E.

    2008-01-01

    Surgical treatment of diseases of the thoracic aorta (aneurysms, dissections, and ruptures) may be associated with serious postoperative complications. Endovascular repair of thoracic aorta pathology is less invasive and offers a therapeutic alternative in high-surgical-risk patients, particularly...... accepted--embolization with endovascular coils--successfully resulting in occlusion of the leakage....

  5. Flux Redux: The Spinning Coil Comes around Again

    Science.gov (United States)

    Lund, Daniel; Dietz, Eric; Zou, Xueli; Ard, Christopher; Lee, Jaydie; Kaneshiro, Chris; Blanton, Robert; Sun, Steven

    2017-01-01

    An essential laboratory exercise for our lower-division electromagnetism course involves the measurement of Earth's local magnetic field from the emf induced in a rotating coil of wire. Although many methods exist for the measurement of Earth's field, this one gives our students some practical experience with Faraday's law. The apparatus we had…

  6. New Development of VPI Process for Large Superconducting Coils

    Institute of Scientific and Technical Information of China (English)

    潘皖江; 武松涛; 崔益民

    2003-01-01

    High vacuum is required for Vacuum Pressure Impregnation (VPI) process of largecoils used in cryogenic. The defects such as dry spots and over rich resins should be minimized inlarge superconducting coils used. Both sealing problems associated with the mold and over richresin problems are eliminated by using vacuum bag mold method with which we can simplify thedesign of vacuum mold.

  7. Simulation of YBCO Tape and Coils in HTS Maglev System

    Directory of Open Access Journals (Sweden)

    Song Mengxiao

    2017-01-01

    Full Text Available In the process of running high temperature superconducting maglev train, the AC(Alternating Current loss of superconducting coil is directly related to its safe operation and operating cost. In this paper, the simulation model was built based on the finite element software COMSOL Multiphysics, and mainly simulated and calculated the AC losses of YBCO(Yttrium Barium Copper Oxide tape and coils. In this model, as the solving object, the singular and infinite long YBCO tape and coils model was solved with H-formulation and the nonlinear characteristic (E-J constitutive law and anisotrophy (B-J characteristic were taken into consideration as the theoretical foundation. Then on the basis of the model under maglev suspension system, AC losses under different amplitude and frequence AC currents were calculated. The results shows that under different frequencies and dynamic components, the local maximum AC loss of YBCO tape and coils occurs when the steady-state DC(Direct Current current is 30A. Then comparing with old maglev suspension system, the new system can greatly reduce the energy consumption and the material cost.

  8. Multiaxial fatigue analysis for IMIC of ITER upper ELM coil

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.W., E-mail: zhangsw@ipp.cn; Song, Y.T.; Wang, Z.W.; Lu, S.; Ji, X.; Du, S.S.; Liu, X.F.; Feng, C.L.; Yang, H.; Wang, S.K.; Luo, Z.R.

    2014-04-15

    Highlights: • The structural analysis provides the initial stresses. • Constant and variation of principal stress direction provide the design codes. • Two methods can be recommended for the ELM coils. • IMIC meets the fatigue criteria. - Abstract: Inconel Jacketed Mineral Insulated Conductor (IMIC) is a very important component of International Thermonuclear Experimental Reactor (ITER) Edge Localized Modes (ELM) coils, which are located between the vacuum vessel (VV) and blanket shield modules and subject to high radiation levels, high temperature and high magnetic field. These coils will experience thermal pulsed, cyclic electromagnetic (EM) load during operation. They are designed to sustain at 1.5e8 total stress cycles and shall have sufficient strength and excellent fatigue to transport and bear the high cyclic load. For IMIC, multiaxial fatigue analysis is used to evaluate failure. Two methods based on the alternating stress and mean stress in American Society of Mechanical Engineers (ASME) code provide the design codes for multiaxial fatigue evaluation: constant principal stress direction and variation of principal stress direction. Results show that using the two methods obtains basically the same equivalent alternating stress. Both of them can be recommended for the ELM coils and IMIC can meet the fatigue criteria.

  9. Low Impedance Voice Coils for Improved Loudspeaker Efficiency

    DEFF Research Database (Denmark)

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

    2015-01-01

    In modern audio systems utilizing switch-mode amplifiers the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 4 to 8 Ohms is obtained, despite modern audio amplifiers, using switch...

  10. 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

    In modern audio systems, utilizing switch-mode amplifiers, the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 3 to 8 Ω are obtained, despite modern audio amplifiers, using switch...

  11. Relationsssship between voice coil fill factor and loudspeaker efficiency

    DEFF Research Database (Denmark)

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

    2016-01-01

    In modern audio systems, utilizing switch-mode amplifiers, the total efficiency is dominated by the rather poor efficiency of the loudspeaker. For decades voice coils have been designed so that nominal resistances of 3 to 8 Ω are obtained, despite modern audio amplifiers, using switch...

  12. Investigating a Quadrant Surface Coil Array for NQR Remote Sensing

    Science.gov (United States)

    2014-10-23

    2006 IEEE James E. Burke received a Bachelors of Science degree in electrical engineering, Florida International University, Miami, Florida...Resonance) remote sensing. In this paper, each of four surface coils will be parallel tuned and series matched with common electrical components to

  13. submitter Electromagnetic Study of a Round Coil Superferric Magnet

    CERN Document Server

    Volpini, Giovanni; Statera, Marco

    2016-01-01

    A novel type of superferric magnets suitable to arbitrary multipole orders was proposed by I. F. Malyshev and later by V. Kashikhin. This new topology, which we refer to as round coil superferric magnets (RCSM), allows a great simplification of the superconducting part, which in the simplest case may be composed by a single round coil, which has intrinsically a rather large bending radius allowing the use of strain-sensitive superconductors. INFN is designing and building a prototype of a multipolar corrector magnet based on this geometry and using MgB2 tapes. In this paper, we investigate a number of issues pertaining to the electromagnetic characteristics of RCSM. The RCSM magnetic has inherently even harmonics, in addition to usual odd ones and a solenoidal component. Either (but not both) disappears when integrated using a one-coil or a two-coil specular design. We investigate the effect of saturation on the multipolar components and on the load line, since in RCSM, saturation plays a role that differs bo...

  14. Comparison of Coil Designs for Transcranial Magnetic Stimulation on Mice

    Science.gov (United States)

    Rastogi, Priyam; Hadimani, Ravi; Jiles, David

    2015-03-01

    Transcranial magnetic stimulation (TMS) is a non-invasive treatment for neurological disorders using time varying magnetic field. The electric field generated by the time varying magnetic field is used to depolarize the brain neurons which can lead to measurable effects. TMS provides a surgical free method for the treatment of neurological brain disorders like depression, post-traumatic stress disorder, traumatic brain injury and Parkinson's disease. Before using TMS on human subjects, it is appropriate that its effects are verified on animals such as mice. The magnetic field intensity and stimulated region of the brain can be controlled by the shape, position and current in the coils. There are few reports on the designs of the coils for mice. In this paper, different types of coils are developed and compared using an anatomically realistic mouse model derived from MRI images. Parameters such as focality, depth of the stimulation, electric field strength on the scalp and in the deep brain regions, are taken into account. These parameters will help researchers to determine the most suitable coil design according to their need. This should result in improvements in treatment of specific disorders. Carver Charitable Trust.

  15. Electromagnetic flat sheet forming by spiral type actuator coil

    Science.gov (United States)

    Akbar, S.; Aleem, M. A.; Sarwar, M. N.; Zillohu, A. U.; Awan, M. S.; Haider, A.; Ahmad, Z.; Akhtar, S.; Farooque, M.

    2016-08-01

    Focus of present work is to develop a setup for high strain rate electromagnetic forming of thin aluminum sheets (0.5, 1.0, 1.5 and 2.0 mm) and optimization of forming parameters. Flat spiral coil of 99.9% pure Cu strip (2.5x8.0 mm) with self-inductance 11 μH, 13 no. of turns and resultant outer diameter of 130mm has been fabricated and was coupled to a capacitor bank of energy, voltage and capacitance of 9 kJ, 900 V and 22.8 mF, respectively. To optimize the coil design, a commercially available software FEMM-4.2 was used to simulate the electromagnetic field profile generated by the coils of different pitch but same number of turns. Results of electromagnetic field intensity proposed by simulation agree in close proximity with those of theoretical as well as experimental data. The calculation of electromagnetic force and magnetic couplings between the coil and metal sheet are made. Forming parameters were optimized for different sheet thicknesses. Electromagnetic field intensity's profile plays a principal role in forming of typical shapes and patterns in sheets.

  16. A Modified Alderman-Grant Coil makes possible an efficient cross-coil probe for high field solid-state NMR of lossy biological samples

    Science.gov (United States)

    Grant, Christopher V.; Yang, Yuan; Glibowicka, Mira; Wu, Chin H.; Park, Sang Ho; Deber, Charles M.; Opella, Stanley J.

    2009-11-01

    The design, construction, and performance of a cross-coil double-resonance probe for solid-state NMR experiments on lossy biological samples at high magnetic fields are described. The outer coil is a Modified Alderman-Grant Coil (MAGC) tuned to the 1H frequency. The inner coil consists of a multi-turn solenoid coil that produces a B 1 field orthogonal to that of the outer coil. This results in a compact nested cross-coil pair with the inner solenoid coil tuned to the low frequency detection channel. This design has several advantages over multiple-tuned solenoid coil probes, since RF heating from the 1H channel is substantially reduced, it can be tuned for samples with a wide range of dielectric constants, and the simplified circuit design and high inductance inner coil provides excellent sensitivity. The utility of this probe is demonstrated on two electrically lossy samples of membrane proteins in phospholipid bilayers (bicelles) that are particularly difficult for conventional NMR probes. The 72-residue polypeptide embedding the transmembrane helices 3 and 4 of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) (residues 194-241) requires a high salt concentration in order to be successfully reconstituted in phospholipid bicelles. A second application is to paramagnetic relaxation enhancement applied to the membrane-bound form of Pf1 coat protein in phospholipid bicelles where the resistance to sample heating enables high duty cycle solid-state NMR experiments to be performed.

  17. Analysis of the factors affecting thermal evolution of hot rolled steel during coil cooling

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The thermal evolution of steel coil during cooling was simulated and investigated by the use of in-house Q-CSP(R) software.The dependence of the thermal evolution of steel coil on cooling methods, temperature distribution of the strip before coiling, coil size and steel grades was also discussed.The study plays a significant role in helping steel makers to better understand and control the cooling process.

  18. Electric field depth–focality tradeoff in transcranial magnetic stimulation: simulation comparison of 50 coil designs

    Science.gov (United States)

    Deng, Zhi-De; Lisanby, Sarah H.; Peterchev, Angel V.

    2012-01-01

    Background Various transcranial magnetic stimulation (TMS) coil designs are available or have been proposed. However, key coil characteristics such as electric field focality and attenuation in depth have not been adequately compared. Knowledge of the coil focality and depth characteristics can help TMS researchers and clinicians with coil selection and interpretation of TMS studies. Objective To quantify the electric field focality and depth of penetration of various TMS coils. Methods The electric field distributions induced by 50 TMS coils were simulated in a spherical human head model using the finite element method. For each coil design, we quantified the electric field penetration by the half-value depth, d1/2, and focality by the tangential spread, S1/2, defined as the half-value volume (V1/2) divided by the half-value depth, S1/2 = V1/2/d1/2. Results The 50 TMS coils exhibit a wide range of electric field focality and depth, but all followed a depth–focality tradeoff: coils with larger half-value depth cannot be as focal as more superficial coils. The ranges of achievable d1/2 are similar between coils producing circular and figure-8 electric field patterns, ranging 1.0–3.5 cm and 0.9–3.4 cm, respectively. However, figure-8 field coils are more focal, having S1/2 as low as 5 cm2 compared to 34 cm2 for circular field coils. Conclusions For any coil design, the ability to directly stimulate deeper brain structures is obtained at the expense of inducing wider electrical field spread. Novel coil designs should be benchmarked against comparison coils with consistent metrics such as d1/2 and S1/2. PMID:22483681

  19. ITER Side Correction Coil Quench model and analysis

    Science.gov (United States)

    Nicollet, S.; Bessette, D.; Ciazynski, D.; Duchateau, J. L.; Gauthier, F.; Lacroix, B.

    2016-12-01

    Previous thermohydraulic studies performed for the ITER TF, CS and PF magnet systems have brought some important information on the detection and consequences of a quench as a function of the initial conditions (deposited energy, heated length). Even if the temperature margin of the Correction Coils is high, their behavior during a quench should also be studied since a quench is likely to be triggered by potential anomalies in joints, ground fault on the instrumentation wires, etc. A model has been developed with the SuperMagnet Code (Bagnasco et al., 2010) for a Side Correction Coil (SCC2) with four pancakes cooled in parallel, each of them represented by a Thea module (with the proper Cable In Conduit Conductor characteristics). All the other coils of the PF cooling loop are hydraulically connected in parallel (top/bottom correction coils and six Poloidal Field Coils) are modeled by Flower modules with equivalent hydraulics properties. The model and the analysis results are presented for five quench initiation cases with/without fast discharge: two quenches initiated by a heat input to the innermost turn of one pancake (case 1 and case 2) and two other quenches initiated at the innermost turns of four pancakes (case 3 and case 4). In the 5th case, the quench is initiated at the middle turn of one pancake. The impact on the cooling circuit, e.g. the exceedance of the opening pressure of the quench relief valves, is detailed in case of an undetected quench (i.e. no discharge of the magnet). Particular attention is also paid to a possible secondary quench detection system based on measured thermohydraulic signals (pressure, temperature and/or helium mass flow rate). The maximum cable temperature achieved in case of a fast current discharge (primary detection by voltage) is compared to the design hot spot criterion of 150 K, which includes the contribution of helium and jacket.

  20. Locating Materials with Nuclear Quadrupole Moments within Surface Coil Array Area

    Science.gov (United States)

    2015-08-11

    The coil resistance is 0.3 ohms on each coil. Both coils were connected to a HP 8753D network analyzer through coaxial cables with 50 ohm BNC...data is post processed at plotted using MATLAB . The graphs show the magnitude of the real and imaginary signals in time and frequency domains

  1. Mathematical Model for Temperature Field of Strip Coil in Cooling and Heating Process

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-quan; SUN Jing-hong; WU Bin; LIAN Jia-chuang

    2005-01-01

    The convection between the strip coil boundary and the surrounding medium was studied,and the math ematical model and boundary conditions for the temperature field of anisotropic strip coil was proposed,and the temperature field of strip coil were calculated by the analytic method.

  2. 78 FR 14403 - Alabama Metal Coil Securement Act; Petition for Determination of Preemption

    Science.gov (United States)

    2013-03-05

    ... Federal Motor Carrier Safety Administration Alabama Metal Coil Securement Act; Petition for Determination... Alabama's Metal Coil Securement Act (the Act) is preempted by Federal law. Federal law provides for... Coil Securement Act The Act, adopted in 2009, prohibits a motor carrier from transporting metal...

  3. An improved asymmetric gradient coil design for high-resolution MRI head imaging

    Science.gov (United States)

    Tang, Fangfang; Liu, Feng; Freschi, Fabio; Li, Yu; Repetto, Maurizio; Giaccone, Luca; Wang, Yaohui; Crozier, Stuart

    2016-12-01

    For head magnetic resonance imaging, local gradient coils are often used to achieve high solution images. To accommodate the human head and shoulder, the head gradient coils are usually designed in an asymmetric configuration, allowing the region-of-uniformity (ROU) close to the coil’s patient end. However, the asymmetric configuration leads to technical difficulties in maintaining a high gradient performance for the insertable head coil with very limited space. In this work, we present a practical design configuration of an asymmetric insertable gradient head coil offering an improved performance. In the proposed design, at the patient end, the primary and secondary coils are connected using an additional radial surface, thus allowing the coil conductors distributed on the flange to ensure an improvement in the coil performance. At the service end, the primary and shielding coils are not connected, to permit access to shim trays, cooling system piping, cabling, and so on. The new designs are compared with conventional coil configurations and the simulation results show that, with a similar field quality in the ROU, the proposed coil pattern has improved construction characteristics (open service end, well-distributed wire pattern) and offers a better coil performance (lower inductance, higher efficiency, etc) than conventional head coil configurations.

  4. 76 FR 72495 - Alabama Metal Coil Securement Act; Petition for Determination of Preemption

    Science.gov (United States)

    2011-11-23

    ... Administration [Docket No. FMCSA-2011-0318] Alabama Metal Coil Securement Act; Petition for Determination of... that the State of Alabama's Metal Coil Securement Act is preempted by Federal law. FMCSA requests comments on what effect, if any, Alabama's metal coil load securement certification requirements may...

  5. The lung volume reduction coil for the treatment of emphysema : a new therapy in development

    NARCIS (Netherlands)

    Klooster, Karin; ten Hacken, Nick H. T.; Slebos, Dirk-Jan

    2014-01-01

    Lung volume reduction (LVR) coil treatment is a novel therapy for patients with severe emphysema. In this bilateral bronchoscopic treatment, approximately 10 LVR coils per lobe are delivered under fluoroscopic guidance in two sequential procedures. The LVR coil reduces lung volume by compressing the

  6. In-vitro thrombogenicity assessment of polymer filament modified and native platinum embolic coils.

    Science.gov (United States)

    Girdhar, Gaurav; Read, Megan; Sohn, Jihae; Shah, Chirag; Shrivastava, Sanjay

    2014-04-15

    Embolic coils have been used to treat intracranial aneurysms using an endovascular approach for more than two decades. However, significant aneurysm recanalization rates have been reported specifically in large and giant aneurysms. Adding filaments to bare Platinum coils is considered a modification and has been proposed to achieve higher aneurysm occlusion rates as compared to bare Platinum coils. Quantitative information - in terms of thrombin generation potential of these modifications - is however lacking. We report here in vitro thrombogenicity of Platinum coils containing Nylon (Axium™ MicroFx™ Nylon coil) and PGLA (Axium™ MicroFx™ PGLA coil) filaments and compare them with equivalent bare Platinum Axium™ coils. We utilize a quantitative method that tracks the formation of thrombin upon exposure of the test samples to human platelet rich plasma using a slow binding fluorogenic substrate. We report a significant increase in the total thrombin turnover, the peak thrombin amount and the rate of thrombin generation for the Axium™ MicroFx™ coils and filaments compared to the Axium™ coils and Platinum wire. Nylon and PGLA filaments added to bare Platinum coils increase thrombogenicity of coils. This study offers a robust quantitative method to compare thrombus formation efficacy of embolic coils under static conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. 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/

  8. Bronchoscopic Lung Volume Reduction Coil Treatment of Patients With Severe Heterogeneous Emphysema

    NARCIS (Netherlands)

    Slebos, Dirk-Jan; Klooster, Karin; Ernst, Armin; Herth, Felix J. F.; Kerstjens, Huib A. M.

    2012-01-01

    Background: The lung volume reduction coil (LVR-coil), a new experimental device to achieve lung volume reduction by bronchoscopy in patients with severe emphysema, works in a manner unaffected by collateral airflow. We investigated the safety and efficacy of LVR-coil treatment in patients with hete

  9. Using Ferromagnetic Material to Extend and Shield the Magnetic Field of a Coil

    Science.gov (United States)

    2017-06-14

    sources , gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden...field sources , magnetic field shaping, magnetic coil enhancement, magnetic coil interactions 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...2 Fig. 3 Two-dimensional calculation of the field of a single-turn coil ( right ) with external metal cladding (left

  10. Assessment of Matrix coils in a canine model of a large bifurcation aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Song, Joon K.; Niimi, Yasunari; Yoshino, Yoshikazu; Khoyama, Shinya; Berenstein, Alejandro [Roosevelt Hospital, Center for Endovascular Surgery, Beth Israel Hyman-Newman Institute for Neurology and Neurosurgery, New York, NY (United States)

    2007-03-15

    Controversy exists as to whether Matrix coils are an improvement over bare platinum coils in preventing aneurysm recanalization in endosaccularly coiled large aneurysms. We investigated Matrix coils in a dog model of a wide-necked large bifurcation aneurysm. Six experimental aneurysms were created in dogs and these aneurysms were endosaccularly coiled with 100% Matrix coils. Angiographic and histopathological data were analyzed at 2 weeks and at 3 months. Average aneurysm dimensions were length 17.8 mm, width 8.3 mm, and neck 6.2 mm. Aneurysm coil filling ranged 24.1-41.8% by volume. At 14 days, three of six Matrix-treated aneurysms showed coil compaction and aneurysm recanalization. At 3 months, one additional Matrix-treated aneurysm showed delayed coil compaction and aneurysm recanalization. At 3 months, in three harvested aneurysms, the average measured neck neointima was 0.150 {+-} 0.14 mm. However, in two of the three aneurysms harvested at 3 months, aneurysm recanalization had occurred with neointimal tissue not completely covering the aneurysm orifice. Thick connective fibrous intercoil tissue was observed. No immediate or delayed thrombus formation had occurred. Based on limited data in an experimental bifurcation aneurysm in dogs, Matrix coils appear to induce a thicker aneurysm neck neointima tissue and intercoil granulation response but appear prone to coil compaction and aneurysm recanalization. Modifications to the Matrix coil are likely needed to improve angiographic results in large aneurysms. (orig.)

  11. Two coiled-coil domains of Chlamydia trachomatis IncA affect membrane fusion events during infection.

    Directory of Open Access Journals (Sweden)

    Erik Ronzone

    Full Text Available Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using a cell-free membrane fusion assay, we found that inhibition of SNARE-mediated fusion requires IncA to be on the same membrane as the endocytic SNARE proteins. IncA displays two coiled-coil domains showing high homology with SNARE proteins. Domain swap and deletion experiments revealed that although both these domains are capable of independently inhibiting SNARE-mediated fusion, these two coiled-coil domains cooperate in mediating IncA multimerization and homotypic membrane interaction. Our results support the hypothesis that Chlamydia employs SNARE-like virulence factors that positively and negatively affect membrane fusion and promote infection.

  12. The SH3 domain of UNC-89 (obscurin) interacts with paramyosin, a coiled-coil protein, in Caenorhabditis elegans muscle

    Science.gov (United States)

    Qadota, Hiroshi; Mayans, Olga; Matsunaga, Yohei; McMurry, Jonathan L.; Wilson, Kristy J.; Kwon, Grace E.; Stanford, Rachel; Deehan, Kevin; Tinley, Tina L.; Ngwa, Verra M.; Benian, Guy M.

    2016-01-01

    UNC-89 is a giant polypeptide located at the sarcomeric M-line of Caenorhabditis elegans muscle. The human homologue is obscurin. To understand how UNC-89 is localized and functions, we have been identifying its binding partners. Screening a yeast two-hybrid library revealed that UNC-89 interacts with paramyosin. Paramyosin is an invertebrate-specific coiled-coil dimer protein that is homologous to the rod portion of myosin heavy chains and resides in thick filament cores. Minimally, this interaction requires UNC-89’s SH3 domain and residues 294–376 of paramyosin and has a KD of ∼1.1 μM. In unc-89 loss-of-function mutants that lack the SH3 domain, paramyosin is found in accumulations. When the SH3 domain is overexpressed, paramyosin is mislocalized. SH3 domains usually interact with a proline-rich consensus sequence, but the region of paramyosin that interacts with UNC-89’s SH3 is α-helical and lacks prolines. Homology modeling of UNC-89’s SH3 suggests structural features that might be responsible for this interaction. The SH3-binding region of paramyosin contains a “skip residue,” which is likely to locally unwind the coiled-coil and perhaps contributes to the binding specificity. PMID:27009202

  13. Two coiled-coil domains of Chlamydia trachomatis IncA affect membrane fusion events during infection.

    Science.gov (United States)

    Ronzone, Erik; Paumet, Fabienne

    2013-01-01

    Chlamydia trachomatis replicates in a parasitophorous membrane-bound compartment called an inclusion. The inclusions corrupt host vesicle trafficking networks to avoid the degradative endolysosomal pathway but promote fusion with each other in order to sustain higher bacterial loads in a process known as homotypic fusion. The Chlamydia protein IncA (Inclusion protein A) appears to play central roles in both these processes as it participates to homotypic fusion and inhibits endocytic SNARE-mediated membrane fusion. How IncA selectively inhibits or activates membrane fusion remains poorly understood. In this study, we analyzed the spatial and molecular determinants of IncA's fusogenic and inhibitory functions. Using a cell-free membrane fusion assay, we found that inhibition of SNARE-mediated fusion requires IncA to be on the same membrane as the endocytic SNARE proteins. IncA displays two coiled-coil domains showing high homology with SNARE proteins. Domain swap and deletion experiments revealed that although both these domains are capable of independently inhibiting SNARE-mediated fusion, these two coiled-coil domains cooperate in mediating IncA multimerization and homotypic membrane interaction. Our results support the hypothesis that Chlamydia employs SNARE-like virulence factors that positively and negatively affect membrane fusion and promote infection.

  14. Accessing Three-Dimensional Crystals with Incorporated Guests through Metal-Directed Coiled-Coil Peptide Assembly.

    Science.gov (United States)

    Nepal, Manish; Sheedlo, Michael J; Das, Chittaranjan; Chmielewski, Jean

    2016-08-31

    Obtaining three-dimensional (3D) protein and peptide crystals on demand requires a precisely orchestrated hierarchical assembly of biopolymer building blocks. In this work, we disclose a metal-ion-mediated strategy to assemble trimeric coiled-coil peptides in a head-to-tail fashion into linear strands with interstrand interactions. This design led to hexagonal 3D peptide crystal formation within 30 min in the presence of divalent metal ions. The crystal morphology could be controlled by varying the metal ion/peptide ratio, resulting in hexagonal discs to rods. Diffraction studies elucidated the head-to-tail arrangement of the coiled-coil linear strands and their hexagonal, antiparallel packing within the crystal. Unsatisfied ligands at the hexagonal ends of the crystals were harnessed as a powerful means to direct His-tagged fluorophores to distinct locations within the crystals. Overall, the designed hierarchical assembly provides a facile means to obtain 3D peptide crystals and incorporate His-tag-based cargoes and may have potential use in drug delivery and sensor design.

  15. Studies of a thermal energy storage unit with ice on coils; Ice on coil gata kori chikunetsuso no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Ito, S.; Miura, N. [Kanagawa Institute of Technology, Kanagawa (Japan)

    1996-10-27

    Study was made of an ice-on-coil heat storage tank for power load levelling. Prior to the prediction of performance of the system as a whole, the performance of the heat storage tank itself needs to be predicted. A brine (35.9% water solution of ethylene glycol) cooled by a refrigerating machine was poured from the upper end of the piping in the heat storage tank (consisting of 19 spiral pipes or coils arranged in parallel in the vertical direction) for the collection of ice around the coils. Ice grew thicker with the passage of time but there was no remarkable decrease in the transfer of heat because there was an increase in the area of contact between ice and water, and the brine exit temperature remained constant over a prolonged period of time. There was a close agreement between experiment results and theoretical conclusions throughout the heat accumulation process, including changes with time in the thickness of ice on the coils, all pointing to the appropriateness of this analytical effort. To melt the ice, water was poured into the tank top at a predetermined rate. Water chilly at 2-4{degree}C was recovered at the tank bottom, stable in the amount produced. As for the use of spiral pipes for making ice, the laminar heat transfer rate in such pipes are supposed to be more than two times higher than that in straight pipes, and this was quite effective in accelerating heat transfer. 7 refs., 11 figs.

  16. SAS-6 coiled-coil structure and interaction with SAS-5 suggest a regulatory mechanism in C. elegans centriole assembly.

    Science.gov (United States)

    Qiao, Renping; Cabral, Gabriela; Lettman, Molly M; Dammermann, Alexander; Dong, Gang

    2012-11-14

    The centriole is a conserved microtubule-based organelle essential for both centrosome formation and cilium biogenesis. Five conserved proteins for centriole duplication have been identified. Two of them, SAS-5 and SAS-6, physically interact with each other and are codependent for their targeting to procentrioles. However, it remains unclear how these two proteins interact at the molecular level. Here, we demonstrate that the short SAS-5 C-terminal domain (residues 390-404) specifically binds to a narrow central region (residues 275-288) of the SAS-6 coiled coil. This was supported by the crystal structure of the SAS-6 coiled-coil domain (CCD), which, together with mutagenesis studies, indicated that the association is mediated by synergistic hydrophobic and electrostatic interactions. The crystal structure also shows a periodic charge pattern along the SAS-6 CCD, which gives rise to an anti-parallel tetramer. Overall, our findings establish the molecular basis of the specific interaction between SAS-5 and SAS-6, and suggest that both proteins individually adopt an oligomeric conformation that is disrupted upon the formation of the hetero-complex to facilitate the correct assembly of the nine-fold symmetric centriole.

  17. Single-coil and dual-coil defibrillator leads and association with clinical outcomes in a complete Danish nationwide ICD cohort

    DEFF Research Database (Denmark)

    Larsen, Jacob M; Hjortshøj, Søren P; Nielsen, Jens C;

    2016-01-01

    BACKGROUND: The best choice of defibrillator lead in patients with routine implantable cardioverter-defibrillator (ICD) is not settled. Traditionally, most physicians prefer dual-coil leads but the use of single-coil leads is increasing. OBJECTIVE: The purpose of this study was to compare clinical...... outcomes in patients with single- and dual-coil leads. METHODS: All 4769 Danish patients 18 years or older with first-time ICD implants from 2007 to 2011 were included from the Danish Pacemaker and ICD Register. Defibrillator leads were 38.9% single-coil leads and 61.1% dual-coil leads. The primary end...... point was all-cause mortality. Secondary end points were lowest successful energy at implant defibrillation testing, first shock failure in spontaneous arrhythmias, structural lead failure, and lead extraction outcomes. RESULTS: Single-coil leads were associated with lower all-cause mortality...

  18. 连续油管酸洗在WAA-1井应用效果评价%Application effect evaluation of coiled tubing acid washing in Well WAA-1

    Institute of Scientific and Technical Information of China (English)

    袁辉; 杨柳

    2012-01-01

    Considering the practical production figures and block mechanism analysis of Well WAA-1, the coiled tubing acid washing measure for removing pollution is proposed, and then the operation background, project design, operation process as well as effect evaluation of coiled tubing acid washing treatment are illustrated in this paper. By adopting the way of tripping the coiled tubing and controlling the lift speed and injecting rate, the acidizing fluid can be distributed equally in the horizontal interval. While wash head impulse vibrate, it will produce pressure agitation to screen pipe to wash deeply and remove damage.%针对南海西部油田WAA-1井的实际生产情况,在堵塞机理分析基础上提出了适合该井解堵的连续油管酸洗措施,对连续油管酸洗作业实施背景、方案设计、施工过程及效果进行了阐述.通过对水平井段采取连续油管拖动以及控制连续油管的上提速度和注入排量来实现水平井段均匀布酸;冲洗头通过脉冲震荡,在管柱内产生压力激动作用于筛管,达到深度清洗、解除污染的目的.

  19. Promoted-Combustion Chamber with Induction Heating Coil

    Science.gov (United States)

    Richardson, Erin; Hagood, Richard; Lowery, Freida; Herald, Stephen

    2006-01-01

    An improved promoted-combustion system has been developed for studying the effects of elevated temperatures on the flammability of metals in pure oxygen. In prior promoted-combustion chambers, initial temperatures of metal specimens in experiments have been limited to the temperatures of gas supplies, usually near room temperature. Although limited elevated temperature promoted-combustion chambers have been developed using water-cooled induction coils for preheating specimens, these designs have been limited to low-pressure operation due to the hollow induction coil. In contrast, the improved promoted-combustion chamber can sustain a pressure up to 10 kpsi (69 MPa) and, through utilization of a solid induction coil, is capable of preheating a metal specimen up to its melting point [potentially in excess of 2,000 F (approximately equal to 1,100 C)]. Hence, the improved promoted combustion chamber makes a greater range of physical conditions and material properties accessible for experimentation. The chamber consists of a vertical cylindrical housing with an inner diameter of 8 in. (20.32 cm) and an inner height of 20.4 in. (51.81 cm). A threaded, sealing cover at one end of the housing can be unscrewed to gain access for installing a specimen. Inlet and outlet ports for gases are provided. Six openings arranged in a helical pattern in the chamber wall contain sealed sapphire windows for viewing an experiment in progress. The base of the chamber contains pressure-sealed electrical connectors for supplying power to the induction coil. The connectors feature a unique design that prevents induction heating of the housing and the pressure sealing surfaces; this is important because if such spurious induction heating were allowed to occur, chamber pressure could be lost. The induction coil is 10 in. (25.4 cm) long and is fitted with a specimen holder at its upper end. At its lower end, the induction coil is mounted on a ceramic base, which affords thermal insulation to

  20. Comparison of a 32-channel head coil and a 2-channel surface coil for MR imaging of the temporomandibular joint at 3.0 T.

    Science.gov (United States)

    Manoliu, Andrei; Spinner, Georg; Wyss, Michael; Filli, Lukas; Erni, Stefan; Ettlin, Dominik A; Ulbrich, Erika J; Kuhn, Felix P; Gallo, Luigi M; Andreisek, Gustav

    2016-01-01

    To quantitatively and qualitatively compare MRI of the temporomandibular joint (TMJ) using a standard TMJ surface coil and a head coil at 3.0 T. 22 asymptomatic volunteers were MR imaged using a 2-channel surface coil (standard TMJ coil) and a 32-channel head coil at 3.0 T (Philips Ingenia; Philips Healthcare, Netherlands). Imaging protocol consisted of an oblique sagittal proton density weighted turbo spin echo sequence (repetition time/echo time, 2700/26 ms). For quantitative assessment, a spherical phantom was imaged using the same sequence including a noise scan and a B1+ scan. Signal-to-noise ratio (SNR) maps and B1+ maps were calculated on a voxelwise basis. For qualitative evaluation, all volunteers underwent MRI of both TMJs with the jaw in the closed position. Two independent blinded readers assessed accuracy of TMJ anatomical representation and overall image quality on a 5-point scale. Quantitative and qualitative measurements were compared between coils using t-tests and Wilcoxon signed-rank test, respectively. Quantitative analysis showed similar B1+ and significantly higher SNR for the head coil than the TMJ surface coil. Qualitative analysis showed significantly better visibility and delineation of clinically relevant anatomical structures of the TMJ, including the articular disc, bilaminar zone and lateral pterygoid muscle. Furthermore, better overall image quality was observed for the head coil than for the TMJ surface coil. A 32-channel head coil is preferable to a standard 2-channel TMJ surface coil when imaging the TMJ at 3.0 T, because it yields higher SNR, thus increasing accuracy of the anatomical representation of the TMJ.

  1. Bare platinum coils vs. HydroCoil in the treatment of unruptured intracranial aneurysms—A single center randomized controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Poncyljusz, Wojciech, E-mail: wponcyl@poczta.onet.pl [Departament of Interventional Radiology, Pomeranian Medical University, Neurointerventional Cath Lab MSW Hospital, Al. Powst. Wielkopolskich 72, 70-111 Szczecin (Poland); Zarzycki, Artur, E-mail: arturzarzycki@o2.pl [Department of Neurosurgery and Pediatric Neurosurgery, Pomeranian Medical University, Unii Lubelskiej 1, 71-242 Szczecin Poland (Poland); Zwarzany, Łukasz, E-mail: zwarzany@gmail.com [Departament of Interventional Radiology, Pomeranian Medical University, Neurointerventional Cath Lab MSW Hospital, Al. Powst. Wielkopolskich 72, 70-111 Szczecin (Poland); Burke, Thomas H., E-mail: tom.burke@microvention.com [Microvention–Terumo, Tustin, CA (United States)

    2015-02-15

    Highlights: • The use of HydroCoil tends to improve immediate angiographic outcome. • Less total number of coils is needed when using HydroCoil. • HydroCoil is equivocal to bare platinum coil. - Abstract: Purpose: The HydroCoil Embolic System (HES) was developed to improve aneurysm filling to provide superior occlusion efficacy, reduce retreatment rates and enhance long-term durability. We performed a randomized clinical trial to compare the effectiveness of bare platinum coils (BPC) vs. HES for unruptured intracranial aneurysms. Methods: Ninety-six patients underwent endovascular coiling of unruptured intracranial aneurysms. The aneurysms were randomized equally to receive BPC or HES. Immediate angiographic results, number of coils used and complications were evaluated and all cases had 12-month follow-up angiography. Results: Immediate angiographic results demonstrated that 84.0% of aneurysms treated with HES were completely occluded compared to 76.1% of aneurysms treated with BPC (p = 0.3310). The mean number of coils utilized to fill the aneurysm was significantly lower in the HES arm (5.04 vs. 6.93). Additional adjunctive techniques were performed in 51.1% of all cases. There were seven patients (7.3%) with postoperative complications during the study period. The coil type used during the treatment did not demonstrate any significant differences on the overall recurrence rate (HES – 18.0%, BPC – 17.4%, p = 0.9712). There was a statistically significant difference in the aneurysm size and the neck width between completely occluded aneurysms and aneurysms with residual flow in both immediate angiographic and mid-term follow-up. Conclusions: Overall, aneurysm size and neck width are the main risk factors associated with aneurysm recurrence. HES compared to BPC required less total number of coils to provide a denser aneurysm filling. However, there were equivocal results with both devices, at the mid-term angiographic follow-up.

  2. Mutual Inductance and Magnetic Force Calculations for Bitter Disk Coil (Pancake) with Nonlinear Radial Current and Filamentary Circular Coil with Azimuthal Current

    OpenAIRE

    Slobodan Babic; Cevdet Akyel

    2016-01-01

    Bitter coils are electromagnets used for the generation of extremely strong magnetic fields superior to 30 T. In this paper we calculate the mutual inductance and the magnetic force between Bitter disk (pancake) coil with the nonlinear radial current and the circular filamentary coil with the azimuthal current. The close form expressed over complete elliptic integrals of the first and second kind as well as Heuman’s Lambda function is obtained for this configuration either for the mutual indu...

  3. Structural basis for cargo binding and autoinhibition of Bicaudal-D1 by a parallel coiled-coil with homotypic registry

    Energy Technology Data Exchange (ETDEWEB)

    Terawaki, Shin-ichi, E-mail: terawaki@gunma-u.ac.jp [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); SPring-8 Center, RIKEN, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Yoshikane, Asuka [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); SPring-8 Center, RIKEN, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Higuchi, Yoshiki [Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); Department of Picobiology, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297 (Japan); SPring-8 Center, RIKEN, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Wakamatsu, Kaori [Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); SPring-8 Center, RIKEN, 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2015-05-01

    Bicaudal-D1 (BICD1) is an α-helical coiled-coil protein mediating the attachment of specific cargo to cytoplasmic dynein. It plays an essential role in minus end-directed intracellular transport along microtubules. The third C-terminal coiled-coil region of BICD1 (BICD1 CC3) has an important role in cargo sorting, including intracellular vesicles associating with the small GTPase Rab6 and the nuclear pore complex Ran binding protein 2 (RanBP2), and inhibiting the association with cytoplasmic dynein by binding to the first N-terminal coiled-coil region (CC1). The crystal structure of BICD1 CC3 revealed a parallel homodimeric coiled-coil with asymmetry and complementary knobs-into-holes interactions, differing from Drosophila BicD CC3. Furthermore, our binding study indicated that BICD1 CC3 possesses a binding surface for two distinct cargos, Rab6 and RanBP2, and that the CC1-binding site overlaps with the Rab6-binding site. These findings suggest a molecular basis for cargo recognition and autoinhibition of BICD proteins during dynein-dependent intracellular retrograde transport. - Highlights: • BICD1 CC3 is a parallel homodimeric coiled-coil with axial asymmetry. • The coiled-coil packing of BICD1 CC3 is adapted to the equivalent heptad position. • BICD1 CC3 has distinct binding sites for two classes of cargo, Rab6 and RanBP2. • The CC1-binding site of BICD1 CC3 overlaps with the Rab6-binding site.

  4. Endovascular Biopsy: Evaluating the Feasibility of Harvesting Endothelial Cells Using Detachable Coils

    Science.gov (United States)

    Cooke, Daniel L.; Su, Hua; Sun, Zhengda; Guo, Yi; Guo, Diana; Saeed, Maythem M.; Hetts, Steven W.; Higashida, Randall T.; Dowd, Christopher F.; Young, William L.; Halbach, Van V.

    2013-01-01

    Summary The absence of safe and reliable methods to harvest vascular tissue in situ limits the discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders such as aneurysms. We investigated the feasibility and comparable efficacy of endothelial cell collection using a spectrum of endovascular coils. Nine detachable coils ranging in k coefficient (0.15-0.24), diameter (4.0 mm-16.0 mm), and length (8.0 cm-47.0 cm) were tested in pigs. All coils were deployed and retrieved within the iliac artery of pigs (three coils/pig). Collected coils were evaluated under light microscopy. The total and endothelial cells collected by each coil were quantified. The nucleated cells were identified by Wright-Giemsa and DAPI stains. Endothelial and smooth muscle cells were identified by CD31 and α-smooth muscle actin antibody staining. Coils were deployed and retrieved without technical difficulty. Light microscopy demonstrated sheets of cellular material concentrated within the coil winds. All coils collected cellular material while five of nine (55.6%) coils retrieved endothelial cells. Coils collected mean endothelial cell counts of 89.0±101.6. Regression analysis demonstrated a positive correlation between increasing coil diameter and endothelial cell counts (R2=0.52, p = 0.029). Conventional detachable coils can be used to harvest endothelial cells. The number of endothelial cells collected by a coil positively correlated with its diameter. Given the widespread use of coils and their well-described safety profile their potential as an endovascular biopsy device would expand the availability of tissue for cellular and molecular analysis. PMID:24355142

  5. Safety of Radioembolization with {sup 90}Yttrium Resin Microspheres Depending on Coiling or No-Coiling of Aberrant/High-Risk Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Paprottka, P. M., E-mail: philipp.paprottka@med.lmu.de, E-mail: philipp.paprottka@med.uni-muenchen.de; Paprottka, K. J., E-mail: karolin.paprottka@med.lmu.de; Walter, A., E-mail: alexandra.Walter@campus.lmu.de [LMU - University of Munich, Department of Clinical Radiology (Germany); Haug, A. R., E-mail: alexander.haug@meduniwien.ac.at [LMU - University of Munich, Department of Nuclear Medicine (Germany); Trumm, C. G., E-mail: christoph.trumm@med.lmu.de [LMU - University of Munich, Department of Clinical Radiology (Germany); Lehner, S., E-mail: sebastian.lehner@med.uni-muenchen.de; Fendler, W. P., E-mail: wolfgang.fendler@med.uni-muenchen.de [LMU - University of Munich, Department of Nuclear Medicine (Germany); Jakobs, T. F., E-mail: tobias.jakobs@barmherzige-muenchen.de [Barmherzige Brueder Munich, Department of Clinical Radiology (Germany); Reiser, M. F., E-mail: maximilian.reiser@med.lmu.de [LMU - University of Munich, Department of Clinical Radiology (Germany); Zech, C. J., E-mail: Christoph.Zech@usb.ch [University Hospital Basel, Clinic of Radiology and Nuclear Medicine, Section Interventional Radiology (Switzerland)

    2015-08-15

    PurposeTo evaluate the safety of radioembolization (RE) with {sup 90}Yttrium ({sup 90}Y) resin microspheres depending on coiling or no-coiling of aberrant/high-risk vessels.Materials and MethodsEarly and late toxicity after 566 RE procedures were analyzed retrospectively in accordance with the National Cancer Institute’s Common Terminology Criteria for Adverse Events (CTCAE v3.0). For optimal safety, aberrant vessels were either coil embolized (n = 240/566, coiling group) or a more peripheral position of the catheter tip was chosen to treat right or left liver lobes (n = 326/566, no-coiling group).ResultsClinically relevant late toxicities (≥Grade 3) were observed in 1 % of our overall cohort. The no-coiling group had significantly less “any” (P = 0.0001) or “clinically relevant” (P = 0.0003) early toxicity. There was no significant difference (P > 0.05) in delayed toxicity in the coiling versus the no-coiling group. No RE-induced liver disease was noted after all 566 procedures.ConclusionRE with {sup 90}Y resin microspheres is a safe and effective treatment option. Performing RE without coil embolization of aberrant vessels prior to treatment could be an alternative for experienced centers.

  6. A Micro Saddle Coil with Switchable Sensitivity for Local High-Resolution Imaging of Luminal Tissue

    OpenAIRE

    Tetsuji Dohi; Kousuke Murashige

    2016-01-01

    This paper reports on a micro saddle coil for local high-resolution magnetic resonance imaging (MRI) fabricated by embedding a flexible coil pattern into a polydimethyilsiloxane (PDMS) tube. We can change the sensitivity of the micro coil by deforming the shape of the coil from a saddle-shaped mode to a planar-shaped mode. The inductance, the resistance, and the Q-factor of the coil in the saddle-shaped mode were 2.45 μH, 3.31 Ω, and 39.9, respectively. Those of the planar-shaped mode were 3....

  7. A novel radio frequency coil for veterinary magnetic resonance imaging system

    Science.gov (United States)

    Meng, Bin; Huang, Kai-Wen; Wang, Wei-Min

    2010-07-01

    In this article, a novel designed radio frequency (RF) coil is designed and built for the imaging of puppies in a V-shape permanent magnetic resonance imaging (MRI) system. Two sets of Helmholtz coil pairs with a V-shape structure are used to improve the holding of an animal in the coil. The homogeneity and the sensitivity of the RF field in the coil are analysed by theoretical calculation. The size and the shape of the new coil are optimized and validated by simulation through using the finite element method (FEM). Good magnetic resonance (MR) images are achieved on a shepherd dog.

  8. HydroCoils, occlusion rates, and outcomes: a large single-center study.

    LENUS (Irish Health Repository)

    O'Hare, A M

    2010-11-01

    The HydroCoil is an expansile hydrogel coil designed to produce a greater degree of volumetric packing within cerebral aneurysms when compared with bare platinum coils. This increased packing is, in turn, believed to decrease the risk of recurrence within aneurysms and hence the risk of their rupture in the long term. The aim of this work was to assess whether the use of HydroCoils and the proportion of HydroCoil used have any influence on the subsequent occlusion and recurrence rates of treated aneurysms.

  9. Design of self-correction coils in a superferric dipole magnet

    Indian Academy of Sciences (India)

    K Ruwali; K Hosoyama

    2012-05-01

    Design of self-correction coils in a superferric dipole magnet is carried out. By adopting the self-correction coil (SCC) scheme, we can do online correction of unwanted fields inside the magnet aperture during the whole operating cycle irrespective of their origin. The self-correction coils are short-circuited superconducting coils of required symmetry placed in the useful aperture of the AC dipole magnet. Design and operation mechanism of self-correction coils in a superferric dipole magnet are discussed in this paper.

  10. Misalignment tolerable coil structure for biomedical applications with wireless power transfer.

    Science.gov (United States)

    Chow, Jeff P W; Chen, Nan; Chung, Henry S H; Chan, Leanne L H

    2013-01-01

    Coil-misalignment is one of the major hurdles for inductively coupled wireless power transfer in applications like retinal prosthesis. Weak magnetic flux linkage due to coil misalignments would significantly impair the power efficiency. A novel receiver configuration with high misalignment tolerance is presented in this paper. The proposed receiver is composed of two receiver coils placed orthogonally, so as to reduce the variation of mutual inductance between transmitting and receiving coils under misalignment conditions. Three different receiver coil structures are analyzed and compared using the same length of wire. Theoretical predictions have been confirmed with measurement results.

  11. Characteristics of aerodynamic sound sources generated by coiled wires in a uniform air-flow

    Science.gov (United States)

    Matsumoto, H.; Nishida, K.; Saitoh, K.

    2003-11-01

    This study deals experimentally with aerodynamic sounds generated by coiled wires in a uniform air-flow. The coiled wire is a model of the hair dryer's heater. In the experiment, the effects of the coil diameter D, wire diameter d and coil spacing s of the coiled wire on the aerodynamic sound have been clarified. The results of frequency analyses of the aerodynamic sounds show that an Aeolian sound is generated by the coiled wire, when s/d is larger than 1. Also the peak frequencies of Aeolian sounds generated by the coiled wires are higher than the ones generated by a straight cylinder having the same diameter d. To clarify the characteristics of the aerodynamic sound sources, the directivity of the aerodynamic sound generated by the coiled wire has been examined, and the coherent function between the velocity fluctuation around the coiled wire and the aerodynamic sound has been calculated. Moreover, the band overall value of coherent output power between the sound and the velocity fluctuations has been calculated. This method has clarified the sound source region of the Aeolian sound generated by the coiled wire. These results show that the Aeolian sound is generated by the arc part of the coiled wire, which is located in the upstream side of the air-flow.

  12. Design and Construction of a Prototype Solenoid Coil for MICE Coupling Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li; Pan, Heng; Guo, XingLong; Xu, FengYu; Liu, XiaoKun; Wu, Hong; Zheng, ShiXian; Green, Michael A; Li, Derun; Virostek, Steve; Zisman, Michael

    2010-06-28

    A superconducting coupling solenoid mounted around four conventional RF cavities, which produces up to 2.6 T central magnetic field to keep the muons within the cavities, is to be used for the Muon Ionization Cooling Experiment (MICE). The coupling coil made from copper matrix NbTi conductors is the largest of three types of magnets in MICE both in terms of 1.5 m inner diameter and about 13MJ stored magnetic energy at full operation current of 210A. The stress induced inside the coil assembly during cool down and magnet charging is relatively high. In order to validate the design method and develop the coil winding technique with inside-wound SC splices required for the coupling coil, a prototype coil made from the same conductor and with the same diameter and thickness but only one-fourth long as the coupling coil was designed and fabricated by ICST. The prototype coil was designed to be charged to strain conditions that are equivalent or greater than would be encountered in the coupling coil. This paper presents detailed design of the prototype coil as well as developed coil winding skills. The analyses on stress in the coil assembly and quench process were carried out.

  13. Heat Transfer Behavior in a Square Duct with Tandem Wire Coil Element Insert

    Institute of Scientific and Technical Information of China (English)

    Smith Eiamsa-ard; Narin Koolnapadol; Pongjet Promvonge

    2012-01-01

    Effects of insertion of tandem wire coil elements used as turbulator on heat transfer and turbulent flow friction characteristics in a uniform heat-flux square duct are experimentally investigated in this work. The experiment is conducted for turbulent flow with the Reynolds number from 4000 to 25000. The wire coil element is inserted into the duct with a view to generating a swirl flow that assists to wash up the flow trapped in the duct corners and then increase the heat transfer rate of the test duct. Apart from the full-length coil, 1D and 2D length coil elements placed in tandem inside the duct with various free-space lengths are introduced to reduce the friction loss. The results obtained from these wire coil element inserts are also compared with those from the smooth duct. The experimental results reveal that the use of wire coil inserts for the full-length coil, 1D and 2D coil elements with a short free-space length leads to a considerable increase in heat transfer and friction loss over the smooth duct with no insert. The full-length wire coil provides higher heat transfer and friction factor than the tandem wire coil elements under the same operating conditions. Also, performance evaluation criteria to assess the real benefits in using the wire coil insert into the square duct are determined.

  14. A subspace-based coil combination method for phased-array magnetic resonance imaging.

    Science.gov (United States)

    Gol Gungor, Derya; Potter, Lee C

    2016-02-01

    Coil-by-coil reconstruction methods are followed by coil combination to obtain a single image representing a spin density map. Typical coil combination methods, such as square-root sum-of-squares and adaptive coil combining, yield images that exhibit spatially varying modulation of image intensity. Existing practice is to first combine coils according to a signal-to-noise criterion, then postprocess to correct intensity inhomogeneity. If inhomogeneity is severe, however, intensity correction methods can yield poor results. The purpose of this article is to present an alternative optimality criterion for coil combination; the resulting procedure yields reduced intensity inhomogeneity while preserving contrast. A minimum mean squared error criterion is adopted for combining coils via a subspace decomposition. Techniques are compared using both simulated and in vivo data. Experimental results for simulated and in vivo data demonstrate lower bias, higher signal-to-noise ratio (about 7×) and contrast-to-noise ratio (about 2×), compared to existing coil combination techniques. The proposed coil combination method is noniterative and does not require estimation of coil sensitivity maps or image mask; the method is particularly suited to cases where intensity inhomogeneity is too severe for existing approaches. © 2015 Wiley Periodicals, Inc.

  15. Power Loss Analysis and Comparison of Segmented and Unsegmented Energy Coupling Coils for Wireless Energy Transfer.

    Science.gov (United States)

    Tang, Sai Chun; McDannold, Nathan J

    2015-03-01

    This paper investigated the power losses of unsegmented and segmented energy coupling coils for wireless energy transfer. Four 30-cm energy coupling coils with different winding separations, conductor cross-sectional areas, and number of turns were developed. The four coils were tested in both unsegmented and segmented configurations. The winding conduction and intrawinding dielectric losses of the coils were evaluated individually based on a well-established lumped circuit model. We found that the intrawinding dielectric loss can be as much as seven times higher than the winding conduction loss at 6.78 MHz when the unsegmented coil is tightly wound. The dielectric loss of an unsegmented coil can be reduced by increasing the winding separation or reducing the number of turns, but the power transfer capability is reduced because of the reduced magnetomotive force. Coil segmentation using resonant capacitors has recently been proposed to significantly reduce the operating voltage of a coil to a safe level in wireless energy transfer for medical implants. Here, we found that it can naturally eliminate the dielectric loss. The coil segmentation method and the power loss analysis used in this paper could be applied to the transmitting, receiving, and resonant coils in two- and four-coil energy transfer systems.

  16. A direct aspiration first pass technique for retrieval of a detached coil.

    Science.gov (United States)

    Masahira, Noritaka; Ohta, Tsuyoshi; Fukui, Naoki; Yanagawa, Toshio; Kondou, Yuichirou; Morimoto, Masanori; Ueba, Tetsuya

    2016-11-01

    A 64-year-old man was referred to our hospital for treatment of a cerebral aneurysm that was incidentally found. The aneurysm was 7 mm in size and located on the left anterior communicating artery. Using a balloon assisted technique, we performed coil embolization. During the second coil insertion, the first coil was dislodged into the anterior communicating artery. We attempted coil retrieval using a snare, which was unsuccessful. We applied a direct aspiration first pass technique (ADAPT) and advanced a Penumbra 4MAX immediately proximal to the dislodged coil; the dislodged coil was then successfully retrieved. ADAPT is a simple procedure for retrieval of a detached coil, and it can be used as an alternative to the snare technique.

  17. A finite difference method for the design of gradient coils in MRI--an initial framework.

    Science.gov (United States)

    Zhu, Minhua; Xia, Ling; Liu, Feng; Zhu, Jianfeng; Kang, Liyi; Crozier, Stuart

    2012-09-01

    This paper proposes a finite-difference (FD)-based method for the design of gradient coils in MRI. The design method first uses the FD approximation to describe the continuous current density of the coil space and then employs the stream function method to extract the coil patterns. During the numerical implementation, a linear equation is constructed and solved using a regularization scheme. The algorithm details have been exemplified through biplanar and cylindrical gradient coil design examples. The design method can be applied to unusual coil designs such as ultrashort or dedicated gradient coils. The proposed gradient coil design scheme can be integrated into a FD-based electromagnetic framework, which can then provide a unified computational framework for gradient and RF design and patient-field interactions.

  18. Quadrature Slotted Surface Coil Pair for Magnetic Resonance Imaging at 4 Tesla: Phantom Study

    Directory of Open Access Journals (Sweden)

    Solis S.E.

    2012-01-01

    Full Text Available A coil array was composed of two slotted surface coils forming a structure with two plates at 900, each one having 6 circular slots and is introduced in this paper. Numerical simulations of the magnetic field of this coil array were performed at 170 MHz using the finite element method to study its behaviour. This coil array was developed for brain magnetic resonance imaging to be operated at the resonant frequency of 170 MHz in the transceiver mode and quadrature driven. Numerical simulations demonstrated that electromagnetic interaction between the coil elements is negligible, and that the magnetic field showed a good uniformity. Phantom images were acquired with our coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. In vitro images showed the feasibility of this coil array for standard pulses and high field magnetic resonance imaging.

  19. Coil motion effects in watt balances: a theoretical check

    Science.gov (United States)

    Li, Shisong; Schlamminger, Stephan; Haddad, Darine; Seifert, Frank; Chao, Leon; Pratt, Jon R.

    2016-04-01

    A watt balance is a precision apparatus for the measurement of the Planck constant that has been proposed as a primary method for realizing the unit of mass in a revised International System of Units. In contrast to an ampere balance, which was historically used to realize the unit of current in terms of the kilogram, the watt balance relates electrical and mechanical units through a virtual power measurement and has far greater precision. However, because the virtual power measurement requires the execution of a prescribed motion of a coil in a fixed magnetic field, systematic errors introduced by horizontal and rotational deviations of the coil from its prescribed path will compromise the accuracy. We model these potential errors using an analysis that accounts for the fringing field in the magnet, creating a framework for assessing the impact of this class of errors on the uncertainty of watt balance results.

  20. LARP Long Nb3Sn Racetrack Coil Program

    Energy Technology Data Exchange (ETDEWEB)

    Wanderer, P.; Ambrosio, G.; Anerella, M.; Barzi, E.; Bossert, R.; Cheng, D.; Cozzolino, J.; Escallier, J.; Ferracin, P.; Ganetis, G.; Ghosh, A. K.; Gupta, R. C.; Hafalia, A. R.; Hannaford, C. R.; Joshi, P.; Kovach, P.; Lietzke, A. F.; Louie, W.; Marone, A.; McInturff, A. D.; Muratore, J.; Nobrega, F.; Schmalzle, J.; Thomas, R.; Turrioni, D.

    2007-06-01

    Development of high-performance Nb{sub 3}Sn quadrupoles is one of the major goals of the LHC Accelerator Research Program (LARP). As part of this program, long racetrack magnets are being made in order to check that the change in coil length that takes place during reaction is correctly accounted for in the quadrupole design and to check for length effects in implementing the 'shell' method of coil support. To check the racetrack magnet manufacturing plan, a short racetrack magnet is being made. This magnet will be the first to use restack-rod process Nb{sub 3}Sn, making it a 'long sample' test vehicle for this new material. The paper reports the reaction and characterization of the Nb{sub 3}Sn, and construction features and test results from the short racetrack magnet. The paper also reports on the status of the construction of the first long racetrack magnet.

  1. A resonant biaxial Helmholtz coil employing a fractal capacitor bank

    Science.gov (United States)

    Martin, James E.

    2013-09-01

    The design and construction of a series resonant biaxial Helmholtz coil for the production of magnetic fields as large as 500 G in the range of 100-2500 Hz is described. Important aspects of ac coil design are discussed, including: minimizing power losses due to the expected Joule heating, self-induced eddy currents, and skin resistance; controlling the stray capacitance; maximizing field homogeneity; and keeping peak voltages at acceptable levels. The design and construction of a computer-controlled, optically isolated fractal capacitor bank is then treated, and various aspects of capacitor selection and characterization were discussed. The system performance is demonstrated, including stability and the possibility of field component dephasing with typical magnetic samples.

  2. A resonant biaxial Helmholtz coil employing a fractal capacitor bank.

    Science.gov (United States)

    Martin, James E

    2013-09-01

    The design and construction of a series resonant biaxial Helmholtz coil for the production of magnetic fields as large as 500 G in the range of 100-2500 Hz is described. Important aspects of ac coil design are discussed, including: minimizing power losses due to the expected Joule heating, self-induced eddy currents, and skin resistance; controlling the stray capacitance; maximizing field homogeneity; and keeping peak voltages at acceptable levels. The design and construction of a computer-controlled, optically isolated fractal capacitor bank is then treated, and various aspects of capacitor selection and characterization were discussed. The system performance is demonstrated, including stability and the possibility of field component dephasing with typical magnetic samples.

  3. Electrophoresis of a DNA Coil Near a Nanopore

    CERN Document Server

    Rowghanian, Payam

    2013-01-01

    Motivated by DNA electrophoresis near a nanopore, we consider the flow field around an "elongated jet", a long thin source which injects momentum into a liquid. This solution qualitatively describes the electro-osmotic flow around a long rigid polymer, where due to electrohydrodynamic coupling, the solvent receives momentum from the electric field. Based on the qualitative behavior of the elongated jet solution, we develop a coarse-grained scheme which reproduces the known theoretical results regarding the electrophoretic behavior of a long rigid polymer and a polymer coil in a uniform field, which we then exploit to analyze the electrophoresis of a polymer coil in the non-uniform field near a nanopore.

  4. A modified Rogowski coil for measurements of hybrid permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Bertsche, K.

    1996-08-01

    For large permanent magnets, as proposed for the Fermilab Recycler Ring, it may be important to quickly verify that the magnet`s strength is correct. This may be important, for example, if a magnet is suspected of having changed due to some sort of accident. The field strength of a pure dipole can be readily measured with a Hall probe, but for indexed dipoles and for quadrupoles a Hall probe will not give very accurate results without precise positioning. We have investigated a different approach, the use of a modified Rogowski coil to measure the magnetic potential of each pole. As long as magnet geometry is fixed and known, measurement of the magnetic potential at each pole gives a good measurement of field strength even for magnets with large quadrupole components. The construction and use of such a coil and the precision of measurements made with it will be discussed. 4 refs., 5 figs.

  5. Mesenteric ischaemia after endovascular coiling of ruptured cerebral aneurysms.

    LENUS (Irish Health Repository)

    Kamel, M H

    2012-02-03

    Three patients were referred to a national neurosurgical centre following CT evidence of subarachnoid haemorrhage. The three patients, who were referred from different institutions within a seven week period, were Fisher grade 3 and WFNS Grade I at all times. Angiography showed a PCOM aneurysm in one case, a ruptured Basilar tip aneurysm and an unruptured ACOM aneurysm in another case, and an ACOM aneurysm in the third case. It was decided that the aneurysms were suitable for endovascular coiling. These patients had unremarkable intraoperative catheterizations and coiling but subsequently deteriorated post-operatively due to mesenteric ischaemia. Two patients required colectomy for mesenteric ischaemia, and the third arrested secondary to sepsis from bowel perforation. We discuss the various causes that may explain this association, and we alert the neurosurgical community for this complication which has not been reported before.

  6. Dipole model test with one superconducting coil; results analysed

    CERN Document Server

    Durante, M; Ferracin, P; Fessia, P; Gauthier, R; Giloux, C; Guinchard, M; Kircher, F; Manil, P; Milanese, A; Millot, J-F; Muñoz Garcia, J-E; Oberli, L; Perez, J-C; Pietrowicz, S; Rifflet, J-M; de Rijk, G; Rondeaux, F; Todesco, E; Viret, P; Ziemianski, D

    2013-01-01

    This report is the deliverable report 7.3.1 “Dipole model test with one superconducting coil; results analysed “. The report has four parts: “Design report for the dipole magnet”, “Dipole magnet structure tested in LN2”, “Nb3Sn strand procured for one dipole magnet” and “One test double pancake copper coil made”. The 4 report parts show that, although the magnet construction will be only completed by end 2014, all elements are present for a successful completion. Due to the importance of the project for the future of the participants and given the significant investments done by the participants, there is a full commitment to finish the project.

  7. Dipole model test with one superconducting coil: results analysed

    CERN Document Server

    Bajas, H; Benda, V; Berriaud, C; Bajko, M; Bottura, L; Caspi, S; Charrondiere, M; Clément, S; Datskov, V; Devaux, M; Durante, M; Fazilleau, P; Ferracin, P; Fessia, P; Gauthier, R; Giloux, C; Guinchard, M; Kircher, F; Manil, P; Milanese, A; Millot, J-F; Muñoz Garcia, J-E; Oberli, L; Perez, J-C; Pietrowicz, S; Rifflet, J-M; de Rijk, G; Rondeaux, F; Todesco, E; Viret, P; Ziemianski, D

    2013-01-01

    This report is the deliverable report 7.3.1 “Dipole model test with one superconducting coil; results analysed “. The report has four parts: “Design report for the dipole magnet”, “Dipole magnet structure tested in LN2”, “Nb3Sn strand procured for one dipole magnet” and “One test double pancake copper coil made”. The 4 report parts show that, although the magnet construction will be only completed by end 2014, all elements are present for a successful completion. Due to the importance of the project for the future of the participants and given the significant investments done by the participants, there is a full commitment to finish the project.

  8. DESIGN OF THE ITER IN-VESSEL COILS

    Energy Technology Data Exchange (ETDEWEB)

    Neumeyer, C; Bryant, L; Chrzanowski, J; Feder, R; Gomez, M; Heitzenroeder, P; Kalish, M; Lipski, A; Mardenfeld, M; Simmons, R; Titus, P; Zatz, I; Daly, E; Martin, A; Nakahira, M; Pillsbury, R; Feng, J; Bohm, T; Sawan, M; Stone, H; Griffiths, I

    2010-11-27

    The ITER project is considering the inclusion of two sets of in-vessel coils, one to mitigate the effect of Edge Localized Modes (ELMs) and another to provide vertical stabilization (VS). The in-vessel location (behind the blanket shield modules, mounted to the vacuum vessel inner wall) presents special challenges in terms of nuclear radiation (~3000 MGy) and temperature (100oC vessel during operations, 200oC during bakeout). Mineral insulated conductors are well suited to this environment but are not commercially available in the large cross section required. An R&D program is underway to demonstrate the production of mineral insulated (MgO or Spinel) hollow copper conductor with stainless steel jacketing needed for these coils. A preliminary design based on this conductor technology has been developed and is presented herein.

  9. Thermodynamic analysis of cavity creating mutations in an engineered leucine zipper and energetics of glycerol-induced coiled coil stabilization.

    Science.gov (United States)

    Dürr, E; Jelesarov, I

    2000-04-18

    Protein stability in vitro can be influenced either by introduction of mutations or by changes in the chemical composition of the solvent. Recently, we have characterized the thermodynamic stability and the rate of folding of the engineered dimeric leucine zipper A(2), which has a strengthened hydrophobic core [Dürr, E., Jelesarov, I., and Bosshard, H. R. (1999) Biochemistry 38, 870-880]. Here we report on the energetic consequences of a cavity introduced by Leu/Ala substitution at the tightly packed dimeric interface and how addition of 30% glycerol affects the folding thermodynamics of A(2) and the cavity mutants. Folding could be described by a two-state transition from two unfolded monomers to a coiled coil dimer. Removal of six methylene groups by Leu/Ala substitutions destabilized the dimeric coiled coil by 25 kJ mol(-1) at pH 3.5 and 25 degrees C in aqueous buffer. Destabilization was purely entropic at around room temperature and became increasingly enthalpic at elevated temperatures. Mutations were accompanied by a decrease of the unfolding heat capacity by 0.5 kJ K(-1) mol(-1). Addition of 30% glycerol increased the free energy of folding of A(2) and the cavity mutants by 5-10 kJ mol(-1) and lowered the unfolding heat capacity by 25% for A(2) and by 50% for the Leu/Ala mutants. The origin of the stabilizing effect of glycerol varied with temperature. Stabilization of the parent leucine zipper A(2) was enthalpic with an unfavorable entropic component between 0 and 100 degrees C. In the case of cavity mutants, glycerol induced enthalpic stabilization below 50 degrees C and entropic stabilization above 50 degrees C. The effect of glycerol could not be accounted for solely by the enthalpy and entropy of transfer or protein surface from water to glycerol/water mixture. We propose that in the presence of glycerol the folded coiled coil dimer is better packed and displays less intramolecular fluctuations, leading to enhanced enthalpic interactions and to an

  10. Feasibility Study: Ductless Hydronic Distribution Systems with Fan Coil Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D.; Dakin, B.; Backman, C.

    2012-07-01

    The primary objectives of this study are to estimate potential energy savings relative to conventional ducted air distribution, and to identify equipment requirements, costs, and barriers with a focus on ductless hydronic delivery systems that utilize water-to-air terminal units in each zone. Results indicate that annual heating and cooling energy use can be reduced by up to 27% assuming replacement of the conventional 13 SEER heat pump and coil with a similarly rated air-to-water heat pump.

  11. Measurement of axial injection displacement with trim coil current unbalance

    Science.gov (United States)

    Covo, Michel Kireeff

    2014-08-01

    The Dee probe used for measuring internal radial beam intensity shows large losses inside the radius of 20 cm of the 88 in. cyclotron. The current of the top and bottom innermost trim coil 1 is unbalanced to study effects of the axial injection displacement. A beam profile monitor images the ion beam bunches, turn by turn. The experimental bunch center of mass position is compared with calculations of the magnetic mirror effect displacement and shows good agreement.

  12. 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 (p<0.01), with a further significant decrease (~7%) from 4–8 weeks (p=0.03) and force levels appearing to remain steady thereafter. Clinical space 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

  13. 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.

  14. Influence of turn-to-turn resistivity and coil geometrical size on charging characteristics of no-electrical-insulation REBCO pancake coils

    Science.gov (United States)

    Wang, Y.; Song, H.

    2016-07-01

    High temperature superconductor (HTS) no-electrical-insulation (NEI) coils demonstrate great advantages in thermal stability and self-protection features. However, an intrinsic delay is observed in the charging process and as a result there maybe a possible settle-out problem. It becomes more critical for large HTS coils with more turns, such as the magnets for the accelerator system and DC induction heater applications. This paper presents detailed studies on the charging characteristics of NEI coils. Firstly, two different no-electrical-insulation coils are wound: the first is directly wound using only REBCO tapes with brass lamination, which is called a no-insulation (NI) coil. The other one is co-wound with stainless steel (SS) strips and REBCO tapes whose copper stabilizer is electroplated, which is called a metallic insulation (MI) coil. Fast discharging tests are performed on the two coils and their equivalent turn-to-turn resistivity is calculated. A similar discharging delay is observed on both coils, but the turn-to-turn resistivity of the SS co-wound coil is much higher than that of the first coil. Then the resistivity data is directly applied to an equivalent circuit network model which is developed to predict the charging behaviours. The model calculates coil voltage, currents along the azimuthal and radial directions, as well as the induced magnetic field. A practical charging time is defined to characterize the field ramping process considering the charging delay between field ramping and current charging. The charging behaviours are extensively analyzed and compared in terms of three primary factors: equivalent turn-to-turn resistivity, coil size and ramping rate. The results show that the charging time increases dramatically with the coil size and may be too long to be practical for large-scale applications using HTS coils with low turn-to-turn resistivity. Increasing the turn-to-turn resistivity enables one to accelerate the charging process

  15. Manufacturing of a REBCO racetrack coil using thermoplastic resin aiming at Maglev application

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, Katsutoshi, E-mail: mizuno.katsutoshi.14@rtri.or.jp; Ogata, Masafumi; Hasegawa, Hitoshi

    2015-11-15

    Highlights: • We propose a novel REBCO coil structure which applies thermoplastic resin. • The thermoplastic resin bonds the coil winding and cooling plates. • The adhesiveness of the resin is strong enough to withstand the thermal stress. • The thermoplastic resin does not cause the degradation because of its high viscosity. • We successfully made a full-scale racetrack REBCO coil with the thermoplastic resin. - Abstract: The REBCO coated conductor is a promising technology for the Maglev application in terms of its high critical temperature. The operating temperature of the on-board magnets can be around 40–50 K with the coated conductor. The REBCO coils are cooled by cryocoolers directly, and hence the thermal design of the REBCO coils significantly changes from that of LTS coils. We have developed a novel REBCO coil structure using thermoplastic resin. The coil is not impregnated and the thermoplastic resin is used to bond the coil winding and the heat transfer members, e.g. copper and aluminum plates. The viscosity of the thermoplastic resin is high enough for the thermoplastic resin not to permeate between the turns in the coil. Therefore, the thermal stress does not occur and the risk of degradation is removed. This paper contains the following three topics. First, the thermal resistance of the thermoplastic resin was measured at cryogenic temperature. Then, a small round REBCO coil was experimentally produced. It has been confirmed that the thermoplastic resin does not cause the degradation and, the adhesion between the coil winding and copper plates withstands the thermal stress. Finally, we successfully produced a full-scale racetrack REBCO coil applying the coil structure with the thermoplastic resin.

  16. Inductively-overcoupled coil design for high resolution magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Bilgen Mehmet

    2006-01-01

    Full Text Available Abstract Background Maintaining the quality of magnetic resonance images acquired with the current implantable coil technology is challenging in longitudinal studies. To overcome this challenge, the principle of 'inductive overcoupling' is introduced as a method to tune and match a dual coil system. This system consists of an imaging coil built with fixed electrical elements and a matching coil equipped with tuning and matching capabilities. Overcoupling here refers to the condition beyond which the peak of the current in the imaging coil splits. Methods The combined coils are coupled inductively to operate like a transformer. Each coil circuit is electrically represented by equivalent lumped-elements. A theoretical analysis is given to identify the frequency response characteristics of the currents in each coil. The predictions from this analysis are translated into experiments and applied to locally image rat spinal cord at 9.4 T using an implantable coil as the imaging coil and an external volume coil as the matching coil. Results The theoretical analysis indicated that strong coupling between the coils divides the resonance peaks on the response curves of the currents. Once these newly generated peaks were tuned and matched to the desired frequency and impedance of operation, in vivo images were acquired from the rat spinal cord at high quality and high resolution. Conclusion After proper implementation, inductive overcoupling provides a unique opportunity for tuning and matching the coil system, and allows reliable and repeatable acquisitions of magnetic resonance data. This feature is likely to be useful in experimental studies, such as those aimed at longitudinally imaging the rat following spinal cord injury.

  17. Resolving coiled shapes reveals new reorientation behaviors in C. elegans

    Science.gov (United States)

    Broekmans, Onno D; Rodgers, Jarlath B; Ryu, William S; Stephens, Greg J

    2016-01-01

    We exploit the reduced space of C. elegans postures to develop a novel tracking algorithm which captures both simple shapes and also self-occluding coils, an important, yet unexplored, component of 2D worm behavior. We apply our algorithm to show that visually complex, coiled sequences are a superposition of two simpler patterns: the body wave dynamics and a head-curvature pulse. We demonstrate the precise Ω-turn dynamics of an escape response and uncover a surprising new dichotomy in spontaneous, large-amplitude coils; deep reorientations occur not only through classical Ω-shaped postures but also through larger postural excitations which we label here as δ-turns. We find that omega and delta turns occur independently, suggesting a distinct triggering mechanism, and are the serpentine analog of a random left-right step. Finally, we show that omega and delta turns occur with approximately equal rates and adapt to food-free conditions on a similar timescale, a simple strategy to avoid navigational bias. DOI: http://dx.doi.org/10.7554/eLife.17227.001 PMID:27644113

  18. Improved transcranial magnetic stimulation coil design with realistic head modeling

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2013-03-01

    We are investigating Transcranial magnetic stimulation (TMS) as a noninvasive technique based on electromagnetic induction which causes stimulation of the neurons in the brain. TMS can be used as a pain-free alternative to conventional electroconvulsive therapy (ECT) which is still widely implemented for treatment of major depression. Development of improved TMS coils capable of stimulating subcortical regions could also allow TMS to replace invasive deep brain stimulation (DBS) which requires surgical implantation of electrodes in the brain. Our new designs allow new applications of the technique to be established for a variety of diagnostic and therapeutic applications of psychiatric disorders and neurological diseases. Calculation of the fields generated inside the head is vital for the use of this method for treatment. In prior work we have implemented a realistic head model, incorporating inhomogeneous tissue structures and electrical conductivities, allowing the site of neuronal activation to be accurately calculated. We will show how we utilize this model in the development of novel TMS coil designs to improve the depth of penetration and localization of stimulation produced by stimulator coils.

  19. Serpentine Coil Topology for BNL Direct Wind Superconducting Magnets

    CERN Document Server

    Parker, Brett

    2005-01-01

    BNL direct wind technology, with the conductor pattern laid out without need for extra tooling (no collars, coil presses etc.) began with RHIC corrector production. RHIC patterns were wound flat and then wrapped on cylindrical support tubes. Later for the HERA-II IR magnets we improved conductor placement precision by winding directly on a support tube. To meet HERA-II space and field quality goals took sophisticated coil patterns, (some wound on tapered tubes). We denote such patterns, topologically equivalent to RHIC flat windings, "planar patterns." Multi-layer planar patterns run into trouble because it is hard to wind across existing turns and magnet leads get trapped at poles. So we invented a new "Serpentine" winding style, which goes around 360 degrees while the conductor winds back and forth on the tube. To avoid making solenoidal fields, we wind Serpentine layers in opposite handed pairs. With a Serpentine pattern each turn can have the same projection on the coil axis and integral field harmonics t...

  20. Seismic analysis of ITER fourth PF (Poloidal Field Coil) feeder

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Sumei, E-mail: smliu@ipp.ac.cn [School of Engineering, Anhui Agricultural University, Hefei 230036 (China); Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Chen, Wei [School of Engineering, Anhui Agricultural University, Hefei 230036 (China); Song, Yuntao; Ni, Xiaojun; Wang, Zhongwei [Institute of Plasma Physics, Chinese Academy of Science, Hefei 230031 (China); Chen, Yonghua; Gong, Chenyu [Magnet Division, TKM, ITER Organization, Route de Vinon sur Verdon, 13115 St. Paul Lez Durance (France)

    2014-10-15

    The ITER feeder systems connect the ITER magnet systems located inside the main cryostat to the cryo-plant, power-supply and control system interfaces outside the cryostat. The main purpose of the feeders is to convey the cryogenic supply and electrical power to the coils as well as house the instrumentation wiring. The PF busbar which carries 52 kA current will suffer from high Lorentz force due to the background magnetic field inspired by the coils and the self-field between every pair of busbars. Except their mechanical strength and thermal insulation performance must be achieved, the dynamic mechanism on PF structure should be assessed. This paper presents the simulation and seismic analysis on ITER 4th PF feeder including the Coil Terminal Box and S-bend Box (CTB and SBB), the Cryostat Feed-through (CFT), the In-Cryostat-Feeder (ICF), especially for the ground supports and main outer-tube firstly. This analysis aims to study seismic resistance on system design under local seismograms with floor response spectrum, the structural response vibration mode and response duration results of displacement, membrane stress, and bending stress on structure under different directions actuating signals were obtained by using the single-seismic spectrum analysis and Dead Weight analysis respectively. Based on the simulative and analytical results, the system seismic resistance and the integrity of the support structure in the 4th PF feeder have been studied and the detail design confirmed.