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Sample records for pyrazole ring forms

  1. 5-Pentyl-4-phenylsulfonyl-1H-pyrazol-3-ol

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    Tara Shahani

    2010-06-01

    Full Text Available In the title compound, C14H18N2O3S, the 1H-pyrazole ring is approximately planar, with a maximum deviation of 0.005 (1 Å. The dihedral angle formed between the 1H-pyrazole and phenyl rings is 79.09 (5°. Pairs of intermolecular N—H...O and O...H...N hydrogen bonds form dimers between neighboring molecules, generating R22(10 ring motifs. These dimers are further linked byintermolecular N—H...O and O—H...N hydrogen bonds into a two-dimensional array parallel to the ac plane. The crystal structure is also stabilized by C—H...π interactions.

  2. [3-(5-Nitro-2-furyl-1-phenyl-1H-pyrazol-4-yl](phenylmethanone

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    Jia Hao Goh

    2010-05-01

    Full Text Available In the title pyrazole compound, C20H13N3O4, an intramolecular C—H...O hydrogen bond generates a seven-membered ring, producing an S(7 ring motif. The essentially planar furan and pyrazole rings [maximum deviations of 0.002 (1 and 0.007 (1 Å, respectively] are coplanar with each other, forming a dihedral angle of 3.06 (10°. The pyrazole ring forms dihedral angles of 8.51 (9 and 56.81 (9° with the two benzene rings. The nitro group is coplanar with the attached furan ring, as indicated by the dihedral angle of 2.5 (3°. In the crystal packing, intermolecular C—H...O hydrogen bonds link adjacent molecules into two-molecule-wide chains along the a axis. The crystal packing is further stabilized by weak intermolecular C—H...π and π–π interactions [centroid–centroid distance = 3.4441 (10 Å].

  3. 4-(1,3-Diphenyl-4,5-dihydro-1H-pyrazol-5-yl-1,3-diphenyl-1H-pyrazole

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    Hoong-Kun Fun

    2011-11-01

    Full Text Available The title compound, C30H24N4, contains two pyrazole rings and four phenyl rings. The pyrazole rings are essentially planar, with maximum deviations of 0.003 (1 and 0.066 (1 Å and make a dihedral angle of 73.43 (6°. The two pyrazole rings make dihedral angles of 40.08 (6, 9.28 (6, 15.78 (8 and 17.25 (7° with their attached phenyl rings. In the crystal, there are no significant intermolecular hydrogen-bonding interactions. The crystal structure is stabilized by C—H...π interactions.

  4. Crystal structure of 1-methoxy-2,2,2-tris(pyrazol-1-ylethane

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    Ganna Lyubartseva

    2014-09-01

    Full Text Available The title compound, C12H14N6O, consists of three pyrazole rings bound via nitrogen to the distal ethane carbon of methoxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14, 73.74 (14, and 78.92 (12°. In the crystal, molecules are linked by bifurcated C—H,H...N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C—H...O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5 inversion twin.

  5. Crystal structure of 1-meth-oxy-2,2,2-tris-(pyrazol-1-yl)ethane.

    Science.gov (United States)

    Lyubartseva, Ganna; Parkin, Sean; Coleman, Morgan D; Mallik, Uma Prasad

    2014-09-01

    The title compound, C12H14N6O, consists of three pyrazole rings bound via nitro-gen to the distal ethane carbon of meth-oxy ethane. The dihedral angles between the three pyrazole rings are 67.62 (14), 73.74 (14), and 78.92 (12)°. In the crystal, mol-ecules are linked by bifurcated C-H,H⋯N hydrogen bonds, forming double-stranded chains along [001]. The chains are linked via C-H⋯O hydrogen bonds, forming a three-dimensional framework structure. The crystal was refined as a perfect (0.5:0.5) inversion twin.

  6. A Convenient Approach to Heterocyclic Building Blocks: Synthesis of Novel Ring Systems Containing a [5,6]Pyrano[2,3-c]pyrazol-4(1H-one Moiety

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    Wolfgang Holzer

    2007-01-01

    Full Text Available Starting from commercially available educts, a straightforward synthetic route to new heterocyclic building blocks is exemplified with the one- or two-step synthesis of tri-, tetra-, or pentacyclic ring systems. Representatives of the following novel ring systems are prepared from 3-methyl-1-phenyl-2-pyrazolin-5-one and the corresponding o-halo-arenecarbonyl chloride using calcium hydroxide in refluxing 1,4-dioxane: pyrimidino[4',5':5,6]pyrano[2,3-c]pyrazol-4(1H-one, thieno[3',2':5,6]pyrano[2,3c]pyrazol- 4-(1H-one, thieno[3',4':5,6]pyrano[2,3-c]pyrazol-4(1H-one, thieno[3'',2'':4',5']thieno[2',3':5,6]-pyrano[2,3-c]pyrazol-4(1H-one, [1,3]dioxolo[5',6'][1]benzothieno[2',3':5,6]pyrano-[2,3-c]- pyrazol-4(1H-one, pyridazino[4',3':5,6]pyrano[2,3-c]pyrazol-4(1H-one and pyrazolo-[4'',3'':5',6']pyrido[3',4':5,6]pyrano[2,3-c]pyrazol-4(1H-one. While the latter two ring systems are directly obtained due to a spontaneous intramolecular substitution reaction, in the other reactions uncyclised 4-aroylpyrazol-5-ols are produced, which are cyclised into the target heterocycles in a subsequent synthetic step (i.e. treatment with NaH in DMF. Detailed NMR spectroscopic investigations (1H-, 13C-, 15N- with the obtained compounds were undertaken to unambiguously prove the new structures.

  7. 5-Isobutyl-4-phenylsulfonyl-1H-pyrazol-3(2H-one

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    M. Venkatesh

    2010-12-01

    Full Text Available The title compound, C13H16N2O3S, consists of two crystallographically independent molecules with similar geometries and exists in a keto form, the C=O bond lengths being 1.267 (2 and 1.254 (2 Å. In both molecules, the pyrazole rings are approximately planar, with maximum deviations of 0.017 (2 and 0.010 (2 Å, and the dihedral angles between the pyrazole and phenyl rings are 83.63 (11 and 70.07 (12°. In one molecule, an intramolecular C—H...O hydrogen bond with an S(6 ring motif is observed. In the crystal, intermolecular N—H...O and C—H...O hydrogen bonds link the molecules into two-dimensional networks parallel to the ab plane.

  8. 2-(2,4-Dichlorophenyl-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylacetamide

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    B. Narayana

    2013-01-01

    Full Text Available In the crystal structure of the title compound, C19H17Cl2N3O2, the molecules form dimers of the R22(10 type through N—H...O hydrogen bonding. As a result of steric repulsion, the amide group is rotated with respect to both the dichlorophenyl and 2,3-dihydro-1H-pyrazol-4-yl rings, making dihedral angles of 80.70 (13 and 64.82 (12°, respectively. The dihedral angle between the dichlorophenyl and 2,3-dihydro-1H-pyrazol-4-yl rings is 48.45 (5° while that between the 2,3-dihydro-1H-pyrazol-4-yl and phenyl rings is 56.33 (6°.

  9. Crystal structure of N′-diphenylmethylidene-5-methyl-1H-pyrazole-3-carbohydrazide

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    Khalid Karrouchi

    2015-11-01

    Full Text Available In the title compound, C18H16N4O, the planes of the phenyl rings are approximately perpendicular to each other [dihedral angle = 78.07 (8°] and form dihedral angles of 56.43 (8 and 24.59 (8° with the pyrazole ring. In the crystal, molecules are linked by N—H...O hydrogen bonds to form one-dimensional chains parallel to the [010] direction.

  10. 4-Methyl-5-phenyl-1H-pyrazol-3-ol

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    Tara Shahani

    2010-07-01

    Full Text Available The title compound, C10H10N2O, crystallizes with two independent molecules in the asymmetric unit, having closely comparable geometries. The dihedral angles between the 1H-pyrazole and benzene rings in the two molecules are 39.57 (14 and 41.95 (13°. The two molecules are each connected to neighbouring molecules by pairs of intermolecular O—H...N hydrogen bonds, forming dimers with R22(8 ring motifs. These dimers are further linked into R44(10 ring motifs by intermolecular N—H...O hydrogen bonds, forming chains along [101]. The crystal structure is further stabilized by a C—H...π interaction.

  11. 2-[3-(4-Methoxyphenyl-1-phenyl-1H-pyrazol-5-yl]phenol

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    2009-03-01

    Full Text Available The title compound, C22H18N2O2, was derived from 1-(2-hydroxyphenyl-3-(4-methoxyphenylpropane-1,3-dione. The central pyrazole ring forms dihedral angles of 16.83 (5, 48.97 (4 and 51.68 (4°, respectively, with the methoxyphenyl, phenyl and hydroxyphenyl rings. The crystal packing is stabilized by O—H...N hydrogen bonding.

  12. 1-[3-(4-Chlorophenyl-5-(4-methoxyphenyl-4,5-dihydro-1H-pyrazol-1-yl]ethanone

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    Hoong-Kun Fun

    2012-04-01

    Full Text Available In the title compound, C18H17ClN2O2, the benzene rings form dihedral angles of 6.69 (6 and 74.88 (5° with the 4,5-dihydro-1H-pyrazole ring. The benzene rings form a dihedral angle of 76.67 (5° with each other. In the crystal, molecules are linked via bifurcated (C,C–H...O hydrogen bonds into chains along [010]. The crystal structure is further consolidated by C—H...π interactions.

  13. Crystal structure of 3-methyl-1-phenyl-5-(1H-pyrrol-1-yl-1H-pyrazole-4-carbaldehyde

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    Joel T. Mague

    2014-10-01

    Full Text Available In the title compound, C15H13N3O, the pyrrolyl and phenyl rings make dihedral angles of 58.99 (5 and 34.95 (5°, respectively, with the central pyrazole ring. In the crystal, weak, pairwise C—H...O interactions across centers of symmetry form dimers, which are further associated into corrugated sheets running approximately parallel to (100 via weak C—H...N interactions.

  14. [2,9-Bis(3,5-dimethyl-1H-pyrazol-1-yl-κN2-1,10-phenanthroline-κ2N,N′]bis(thiocyanato-κNcadmium(II

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    Yan Hui Chi

    2011-01-01

    Full Text Available In the title complex, [Cd(NCS2(C22H20N6], the CdII ion is in a CdN6 coordination geometry which is intermediate between octahedral and trigonal–prismatic. The dihedral angles formed between the mean planes of the pyrazole rings and the phenanthroline system are 15.74 (15 and 16.30 (13°. In the crystal, there is a π–π stacking interaction involving two symmetry-related pyrazole rings, with a centroid–centroid distance of 3.664 (3 Å. In addition, there is a relatively short intermolecular contact between C atoms [C...C = 3.399 (6 Å] involving symmetry-related pyridine rings along the a axis.

  15. Analgesic Activity of Some 1,2,4-Triazole Heterocycles Clubbed with Pyrazole, Tetrazole, Isoxazole and Pyrimidine

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    Gajanan Khanage, Shantaram; Raju, Appala; Baban Mohite, Popat; Bhanudas Pandhare, Ramdas

    2013-01-01

    Purpose: In the present study in vivo analgesic activity of some previously synthesized 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine ring have been evaluated. Methods: Acetic acid induced writhing method and Hot plate method has been described to study analgesic activity of some 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine as a pharmacological active lead. Results: Thirty six different derivatives con...

  16. Antimalarial activity of 4-(5-trifluoromethyl-1H-pyrazol-1-yl)-chloroquine analogues.

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    Cunico, Wilson; Cechinel, Cleber A; Bonacorso, Helio G; Martins, Marcos A P; Zanatta, Nilo; de Souza, Marcus V N; Freitas, Isabela O; Soares, Rodrigo P P; Krettli, Antoniana U

    2006-02-01

    The antimalarial activity of chloroquine-pyrazole analogues, synthesized from the reaction of 1,1,1-trifluoro-4-methoxy-3-alken-2-ones with 4-hydrazino-7-chloroquinoline, has been evaluated in vitro against a chloroquine resistant Plasmodium falciparum clone. Parasite growth in the presence of the test drugs was measured by incorporation of [(3)H]hypoxanthine in comparison to controls with no drugs. All but one of the eight (4,5-dihydropyrazol-1-yl) chloroquine 2 derivatives tested showed a significant activity in vitro, thus, are a promising new class of antimalarials. The three most active ones were also tested in vivo against Plasmodium berghei in mice. However, the (pyrazol-1-yl) chloroquine 3 derivatives were mostly inactive, suggesting that the aromatic functionality of the pyrazole ring was critical.

  17. 2-(3,5-Dimethyl-1H-pyrazol-1-yl-2-hydroxyimino-N′-[1-(pyridin-2-ylethylidene]acetohydrazide

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    Maxym O. Plutenko

    2012-12-01

    Full Text Available In the title compound, C14H16N6O2, the dihedral angles formed by the mean plane of the acetohydrazide group [maximum deviation 0.0629 (12 Å] with the pyrazole and pyridine rings are 81.62 (6 and 38.38 (4° respectively. In the crystal, molecules are connected by N—H...O and O—H...N hydrogen bonds into supramolecular chains extending parallel to the c-axis direction.

  18. Polymerization of 1,3-butadiene catalyzed by pincer cobalt(II) complexes derived from 2-(1-arylimino)-6-(pyrazol-1-yl)pyridine ligands

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    Gong, Dirong

    2013-08-01

    A new class of air stable and structurally well-defined cobalt complexes with unsymmetrical pincer type ligands ([2-(ArNCMe)-6-(Py)C5H 3N]CoCl2) (Ar = C6H5, Py = pyrazol-1-yl, 5a; Ar = 2,4,6-Me3C6H2, Py = pyrazol-1-yl, 5b; Ar = 2,6-iPr2C6H3, Py = pyrazol-1-yl, 5c; Ar = C6H5, Py = 3,5-Me 2pyrazol-1-yl, 5d; Ar = 2,4,6-Me3C6H 2, Py = 3,5-Me2pyrazol-1-yl, 5e; Ar = 2,6- iPr2C6H3, Py = 3,5-Me 2pyrazol-1-yl, 5f; Ar = 2,6-iPr2C 6H3, Py = 3,5-iPr2pyrazol-1-yl, 5g and [2-(OCMe)-6-(3,5-diphenylpyrazol-1-yl)C5H3N]CoCl 2 5h) were prepared and the molecular structures of 5a, 5c and 5f were determined by single crystal X-ray crystallography. Upon activation by methylaluminoxane (MAO) in toluene at room temperature, all complexes initiate polymerization of 1,3-butadiene (polymer yields: 65-99%), affording polybutadiene with excellent cis-1,4 regularity (97.5-98.7%). The polymer yields and properties in terms of molecular weight and distribution are well controlled by the substituents on iminoaryl rings and pyrazole rings. Selectivity switch from cis-1,4 to syndio-1,2 was also achievable by adding phosphine as microstructure regulator. © 2013 Elsevier B.V. All rights reserved.

  19. Simple assembly of polysubstituted pyrazoles and isoxazoles via ring closure-ring opening domino reaction of 3-acyl-4,5-dihydrofurans with hydrazines and hydroxylamine.

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    Chagarovskiy, Alexey O; Budynina, Ekaterina M; Ivanova, Olga A; Rybakov, Victor B; Trushkov, Igor V; Melnikov, Mikhail Ya

    2016-03-14

    A convenient general approach to 2-(pyrazol-4-yl)- and 2-(isoxazol-4-yl)ethanols based on the Brønsted acid-initiated reaction of 3-acyl-4,5-dihydrofurans with hydrazines or hydroxylamine was developed. Further transformation of the alcohol moiety in 2-(pyrazolyl)ethanols affording 2-(pyrazolyl)ethylamine as potent bioactive compounds as well as pyrazole-substituted derivatives of antitumor alkaloid crispine A was elaborated.

  20. 5-(2,4-Dichlorophenoxy-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde

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    S. Madan Kumar

    2016-07-01

    Full Text Available In the crystal structure of the title compound, C17H12Cl2N2O2, the pyrazole ring makes dihedral angles of 65.0 (2 and 43.9 (2° with the dichlorophenyl and phenyl rings, respectively. The dihedral angle between the chlorophenyl and phenyl rings is 59.1 (2°. In the crystal, the molecules are linked by C—H...O hydrogen bonds and weak C—Cl...π and C—H...π interactions, generating a three-dimensional network.

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

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    Zeliha Baktır

    2011-02-01

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

  2. 1,5-Dimethyl-4-(1-methyl-3-oxo-3-phenylprop-1-enylamino-2-phenyl-1H-pyrazol-3(2H-one

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    Hualing Zhu

    2011-07-01

    Full Text Available In the title compound, C21H21N3O2, an intramolecular N—H...O interaction generates an S(6 ring, which stablizes the enamine–keto tautomer. The S(6 ring makes dihedral angles of 33.07 (7, 56.50 (8 and 38.59 (8°, respectively, with the benzoylacetone benzene ring and the antipyrine pyrazole and benzene rings.

  3. Analgesic Activity of Some 1,2,4-Triazole Heterocycles Clubbed with Pyrazole, Tetrazole, Isoxazole and Pyrimidine

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    Ramdas Bhanudas Pandhare

    2013-02-01

    Full Text Available Purpose: In the present study in vivo analgesic activity of some previously synthesized 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine ring have been evaluated. Methods: Acetic acid induced writhing method and Hot plate method has been described to study analgesic activity of some 1,2,4-triazole derivatives containing pyrazole, tetrazole, isoxazole and pyrimidine as a pharmacological active lead. Results: Thirty six different derivatives containing 1,2,4-triazole ring were subjected to study their in vivo analgesic activity. Chloro, nitro and methoxy, hydroxy and bromo substituted derivatives showed excellent analgesic activity and dimethylamino, furan and phenyl substituted derivatives showed moderate analgesic activity in both of the methods. Compounds IIIa, IIId, IIIf, IIIi, IIIj, IVa, IVb, IVd, IVf, IVh, IVj IV3a and IIj were found to be superior analgesic agents after screening by Acetic acid induced writhing method. Compounds IIIb, IIId, IIIf, IIIh, IIIj, IVa, IVb, IVd, IVf, IVh, IVi, IV3c, IV3e and IIj were showed analgesic potential after screening of Hot plate method. Conclusion: All tested compounds containing 1,2,4-triazole were found to be promising analgesic agents, for this activity pyrazole, tetrazole, isoxazole and pyrimidine leads might be supported.

  4. Synthesis and antifungal activity of the derivatives of novel pyrazole carboxamide and isoxazolol pyrazole carboxylate.

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    Sun, Jialong; Zhou, Yuanming

    2015-03-09

    A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy). Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani) using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  5. Bis[1-methoxy-2,2,2-tris(pyrazol-1-yl-κN2ethane]nickel(II bis(trifluoromethanesulfonate dihydrate

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    Ganna Lyubartseva

    2013-10-01

    Full Text Available In the title salt, [Ni(C12H14N6O2](CF3SO32·2H2O, the NiII cation is located on an inversion centre and is coordinated by six N atoms from two tridentate 1-methoxy-2,2,2-tris(pyrazol-1-ylethane ligands in a distorted octahedral geometry. The Ni—N distances range from 2.0594 (12 to 2.0664 (12 Å, intra-ligand N—Ni—N angles range from 84.59 (5 to 86.06 (5°, and adjacent inter-ligand N—Ni—N angles range between 93.94 (5 and 95.41 (5°. In the crystal, inversion-related pyrazole rings are π–π stacked, with an interplanar spacing of 3.4494 (18 Å, forming chains that propagate parallel to the a-axis direction. Intermolecular O—H...O hydrogen bonds are present between water molecules and trifluoromethanesulfonate anions.

  6. Synthesis and Antifungal Activity of the Derivatives of Novel Pyrazole Carboxamide and Isoxazolol Pyrazole Carboxylate

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    Jialong Sun

    2015-03-01

    Full Text Available A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy. Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  7. 3,5-Bis(4-meth-oxy-phen-yl)-1-phenyl-4,5-dihydro-1H-pyrazole.

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

    2011-01-12

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

  8. 1-[(6-Chloro-3-pyridylmethyl]-N-(4-ethoxyphenyl-3-phenyl-1H-pyrazole-5-carboxamide

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    Zheng Tang

    2009-04-01

    Full Text Available In the title compound, C24H21ClN4O2, the pyrazole ring makes dihedral angles of 7.70 (11, 89.17 (11 and 40.68 (11° with the phenyl, pyridine and ethoxyphenyl rings, respectively. There are some intramolecular C—H...O and C—H...π bonds giving rigidity to the molecule, while weak intermolecular N—H...N and C—H...π hydrogen bonds link the molecules into a two-dimensional structure.

  9. 3-Isobutyl-4-phenylsulfanyl-1H-pyrazol-5-ol

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    Tara Shahani

    2011-02-01

    Full Text Available The asymmetric unit of the title compound, C13H16N2OS, contains two independent molecules (A and B. The pyrazole ring [maximum deviations = 0.0049 (17 Å in molecule A and 0.0112 (19 Å in molecule B] makes a dihedral angle of 70.23 (11 and 73.18 (12° with the phenyl ring in molecules A and B, respectively. The isobutyl group in molecule B is disordered over two sets of sites with a ratio of refined occupancies of 0.858 (5:0.142 (5. In the crystal, molecules A and B are linked via a pair of intermolecular N—H...O hydrogen bonds, generating an R22(8 ring motif. These ring motifs are further linked into two-dimensional arrays parallel to the bc plane by intermolecular N—H...O and weak C—H...S hydrogen bonds. The crystal is further stablized by weak π–π interactions [centroid–centroid distances = 3.5698 (13 and 3.5287 (12 Å].

  10. 1-{3-[1-(Hydroxyiminoethyl]-4-methyl-1H-pyrazol-5-yl}ethanone

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    Matti Haukka

    2011-10-01

    Full Text Available In the title compound, C8H11N3O2, the oxime and the acetyl groups adopt a transoid conformation, while the pyrazole H atom is localized in the proximity of the acetyl group and is cis with respect to the acetyl O atom. In the crystal, dimers are formed as the result of hydrogen-bonding interactions involving the pyrazole NH group of one molecule and the carbonyl O atom of another. The dimers are associated into sheets via O—H...N hydrogen bonds involving the oxime hydroxyl and the unprotonated pyrazole N atom, generating a macrocyclic motif with six molecules.

  11. 1,5-Dimethyl-2-phenyl-1H-pyrazol-3(2H-one–4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] (1/1

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    Krzysztof Lyczko

    2013-01-01

    Full Text Available The asymmetric unit of the title compound, C11H12N2O·C25H28N4O2, contains two different molecules. The smaller is known as antipyrine [systematic name: 1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] and the larger is built up from two antypirine molecules which are connected through a C atom of the pyrazolone ring to a central propanyl part [systematic name: 4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one]. Intramolecular C—H...O hydrogen bonds occur in the latter molecule. In the crystal, C—H...O hydrogen bonds link the molecules into a two-dimensional network parallel to (001.

  12. Crystal structure of 3-{5-[3-(4-fluorophenyl-1-isopropyl-1H-indol-2-yl]-1H-pyrazol-1-yl}indolin-2-one ethanol monosolvate

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    Md. Lutfor Rahman

    2016-03-01

    Full Text Available The title indolin-2-one compound, C28H23FN4O·C2H6O, crystallizes as a 1:1 ethanol solvate. The ethanol molecule is disordered over two positions with refined site occupancies of 0.560 (14 and 0.440 (14. The pyrazole ring makes dihedral angles of 84.16 (10 and 85.33 (9° with the indolin-2-one and indole rings, respectively, whereas the dihedral angle between indolin-2-one and indole rings is 57.30 (7°. In the crystal, the components are linked by N—H...O and O—H...O hydrogen bonds, forming an inversion molecule–solvate 2:2 dimer with R44(12 ring motifs. The crystal structure is consolidated by π–π interaction between pairs of inversion-related indolin-2-one rings [interplanar spacing = 3.599 (2 Å].

  13. Synthesis, basicity and complexation properties versus Zn (II) of a new acyclic acceptor of proton-ionizing pyrazole and pyridine; Sintesis, basicidad y propiedades complejantes frente a Zn (II) de un nuevo receptor aciclico de pirazol y piridina proton-ionizable

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, J.M.; Campayo, L.; Navarro, P.; Acerete, C. [Instituto de Quimica Medica, CSIC (Spain)

    1995-12-31

    The synthesis of bis (2`-pyridyl methyl) N{sub 1}-H pyrazole 3,5-dicarboxylate 1[L] is reported. The formation of its sodium pyrazolate salt 1`[L] has been studied by ``13 CNMR, and the deprotonation pKa value of the pyrazole ring of 1 and those corresponding to the protonation of their pyridine rings have been measured using potentiometric methods in H{sub 2}O-MeOH (v/v 9:1) Starting from 1[L] or 1`[L-], the formation of mono- and dinuclear complexes 2 Zn[L] and 3[Zn]{sub 2}[L-]``3+ respectively has been studied. (Author) 17 refs.

  14. 5-(4-Methoxyphenyl-4-methyl-1-phenyl-3-p-tolyl-1H-pyrazole

    Directory of Open Access Journals (Sweden)

    Yahya Ben Soumane

    2017-11-01

    Full Text Available The title compound, C24H22N2O, crystallizes with two independent molecules (A and B in the asymmetric unit. The phenyl, p-tolyl and p-methoxyphenyl rings are inclined to the pyrazole ring by 42.5 (2, 17.68 (19 and 52.20 (19°, respectively, in molecule A, and by 39.5 (2, 40.77 (19 and 59.76 (18°, respectively, in molecule B. In the asymmetric unit, the pyrarole ring of molecule A makes a dihedral angle of 3.7 (2° with that of molecule B. In the crystal, the two independent molecules are linked to each other by a C—H...O hydrogen bond.

  15. 1-{3-[1-(Hydroxyimino)ethyl]-4-methyl-1H-pyrazol-5-yl}ethanone

    Science.gov (United States)

    Malinkin, Sergey; Penkova, Larysa; Pavlenko, Vadim A.; Haukka, Matti; Pavlova, Svetlana V.

    2011-01-01

    In the title compound, C8H11N3O2, the oxime and the acetyl groups adopt a transoid conformation, while the pyrazole H atom is localized in the proximity of the acetyl group and is cis with respect to the acetyl O atom. In the crystal, dimers are formed as the result of hydrogen-bonding inter­actions involving the pyrazole NH group of one mol­ecule and the carbonyl O atom of another. The dimers are associated into sheets via O—H⋯N hydrogen bonds involving the oxime hydroxyl and the unprotonated pyrazole N atom, generating a macrocyclic motif with six mol­ecules. PMID:22058770

  16. Synthesis and antimicrobial evaluation of some new pyrazole, pyrazoline and chromeno[3,4-c]pyrazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Abunada, Nada M.; Miqdad, Omar A. [Al-Aqsa University, Gaza (Palestinian Territory, Occupied). Faculty of Applied Sciences. Dept. of Chemistry; Hassaneen, Hamdi M. [Cairo University, Cairo (Egypt). Faculty of Science. Dept. of Chemistry; Samaha, Ahmed S. M. Abu [Al-Aqsa University, Gaza (Palestinian Territory, Occupied). Faculty of Applied Sciences. Dept. of Biology

    2009-07-01

    Some new pyrazole-5-carbonitrile derivatives 8,9 and pyrazole-5-carboxamide 13 were synthesized by the cycloaddition reaction of nitrilimines 3,4 to alpha-cyanocinnamonitriles 5a-f and alpha-cyanocinnamamide 12a,b respectively. On the other hand 3,4 add to ethyl alpha-cyanocinnamate 14a-f to give ethyl 2-pyrazoline-5-carboxylate derivatives 15,16. Also, cycloaddition of 3,4 to 3-cyanocoumarin 19a or 3-phenylsulphonylcoumarin 19b or 3-bromocoumarin 19c give chromeno[3,4-c]pyrazol-4(3H)-one derivatives 20. In the same direction, the cycloaddition of 3,4 to 3-acetylcoumarin 22 and 3-benzoylcoumarin 23 gives the corresponding dihydrochromeno[3,4-]pyrazol-4(3H)-one 24 and 25 respectively. Oxidation of 24 and 25 give 20. Most of the prepared compounds showed good to moderate antibacterial and antifungal activities. (author)

  17. 3,5-Bis(4-meth­oxy­phen­yl)-1-phenyl-4,5-dihydro-1H-pyrazole

    OpenAIRE

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

    2011-01-01

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

  18. Design, Synthesis and Fungicidal Activities of Some Novel Pyrazole Derivatives

    Directory of Open Access Journals (Sweden)

    Xue-Ru Liu

    2014-09-01

    Full Text Available In order to discover new compounds with good fungicidal activities, 32 pyrazole derivatives were designed and synthesized. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR, and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS, and their fungicidal activities against Botrytis cinerea, Rhizoctonia solani Kuhn, Valsa mali Miyabe et Yamada, Thanatephorus cucumeris (Frank Donk, Fusarium oxysporum (S-chl f.sp. cucumerinum Owen, and Fusarium graminearum Schw were tested. The bioassay results indicated that most of the derivatives exhibited considerable antifungal activities, especially compound 26 containing a p-trifluoromethyl- phenyl moiety showed the highest activity, with EC50 values of 2.432, 2.182, 1.787, 1.638, 6.986, and 6.043 μg/mL against B. cinerea, R. solani, V. mali, T. cucumeris, F. oxysporum, and F. graminearum, respectively. Moreover, the activities of compounds such as compounds 27–32 were enhanced by introducing isothiocyanate and carboxamide moieties to the 5-position of the pyrazole ring.

  19. Crystal Structure of N,N-bis-(3-Carbomethoxy-5-methyl-pyrazol-1-ylmethylaniline

    Directory of Open Access Journals (Sweden)

    Taibi Ben-Hadda

    2002-09-01

    Full Text Available The tripodal ligand N,N-bis-(3-carbomethoxy-5-methylpyrazol-1-ylmethyl aniline (2 has been prepared by the condensation of aniline with two equivalents of N-hydroxymethyl[3-carbomethoxy-5-methyl]pyrazole. The molecule consists of two structurally analogous 3-carbomethoxy-5-methylpyrazol-1-ylmethyl moieties, which adopt a transoidal conformation via a central aniline ring, suggesting that this tripodal ligand is highly flexible and could accommodate many metals by coordination.

  20. Tetraethylammonium tris(thiocyanato-κN[tris(1H-pyrazol-1-yl-κN2methane]nickelate(II

    Directory of Open Access Journals (Sweden)

    Ganna Lyubartseva

    2012-07-01

    Full Text Available The title salt, (C8H20N[Ni(NCS3(C10H10N6], consists of a tetraethylammonium cation and an anion comprising an octahedral NiII atom surrounded by three N atoms from a tripodal tris(pyrazol-1-ylmethane ligand, and three thiocyanate ligands, each bound at the N-atom end. The ligand Ni—N distances range from 2.097 (2 to 2.127 (2 Å for the tripodal ligand and from 2.045 (2 to 2.075 (2 Å for the thiocyanate ligands. The dihedral angles between the three pyrazole rings are 59.03 (12, 53.09 (10 and 67.90 (10°.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Maksym Seredyuk

    2011-11-01

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

  3. N-{2-[2-(5-Methyl-1H-pyrazol-3-ylacetamido]phenyl}benzamide monohydrate

    Directory of Open Access Journals (Sweden)

    Karim Chkirate

    2017-02-01

    Full Text Available The asymmetric unit of the title compound, C19H18N4O2·H2O, comprises the U-shaped pyrazole derivative and a solvent water molecule. The molecular conformation is partly determined by an intramolecular N—H...O hydrogen bond. The crystal packing is directed by an extensive network of O—H...O, N—H...O, N—H...N and C—H...O hydrogen bonds together with C—H...π(ring contacts that generate a three-dimensional network.

  4. Different molecular conformations co-exist in each of three 2-aryl-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamides: hydrogen bonding in zero, one and two dimensions.

    Science.gov (United States)

    Narayana, Badiadka; Yathirajan, Hemmige S; Rathore, Ravindranath S; Glidewell, Christopher

    2016-09-01

    4-Antipyrine [4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one] and its derivatives exhibit a range of biological activities, including analgesic, antibacterial and anti-inflammatory, and new examples are always of potential interest and value. 2-(4-Chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C19H18ClN3O2, (I), crystallizes with Z' = 2 in the space group P\\overline{1}, whereas its positional isomer 2-(2-chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, (II), crystallizes with Z' = 1 in the space group C2/c; the molecules of (II) are disordered over two sets of atomic sites having occupancies of 0.6020 (18) and 0.3980 (18). The two independent molecules of (I) adopt different molecular conformations, as do the two disorder components in (II), where the 2-chlorophenyl substituents adopt different orientations. The molecules of (I) are linked by a combination of N-H...O and C-H...O hydrogen bonds to form centrosymmetric four-molecule aggregates, while those of (II) are linked by the same types of hydrogen bonds forming sheets. The related compound N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-(3-methoxyphenyl)acetamide, C20H21N3O3, (III), is isomorphous with (I) but not strictly isostructural; again the two independent molecules adopt different molecular conformations, and the molecules are linked by N-H...O and C-H...O hydrogen bonds to form ribbons. Comparisons are made with some related structures, indicating that a hydrogen-bonded R2(2)(10) ring is the common structural motif.

  5. Ultrasound-promoted iodination of pyrazoles in aqueous medium

    Directory of Open Access Journals (Sweden)

    Jéssica Kunsminskas

    2012-06-01

    Full Text Available Several pharmacological activities have been devoted to pyrazole containing molecules. In particular, 4-iodopyrazoles have been employed as key starting materials in cross-coupling chemistry and metal-iodine exchange reactions that focus on the synthesis of such biologically important compounds. Unfortunately, existing methods for the synthesis of 4-iodopyrazoles are not in agreement with the environmental requirements due to a series of drawbacks including the use of large excess of reagents, the generation of toxic waste and long reaction times. Recently, we developed a fast and mild reaction condition for the iodination of aromatic compounds using an I2/H2O2 system water as a nonflammable and innocuous solvent and ultrasonic irradiation as energy source. In this work, we present the application of this methodology for the iodination of pyrazoles (Scheme. Initially, a series of pyrazoles were efficiently prepared starting from 1,3-dicarbonyl compounds and hydrazines under ultrasonic irradiation. Three examples from the pyrazoles were subjected to the iodination condition shown above. Iodopyrazoles were obtained in 63-65% yields.

  6. Synergistic effect of pyrazoles derivatives and doxorubicin in claudin-low breast cancer subtype.

    Science.gov (United States)

    Saueressig, Silvia; Tessmann, Josiane; Mastelari, Rosiane; da Silva, Liziane Pereira; Buss, Julieti; Segatto, Natalia Vieira; Begnini, Karine Rech; Pacheco, Bruna; de Pereira, Cláudio Martin Pereira; Collares, Tiago; Seixas, Fabiana Kömmling

    2018-02-01

    Breast cancer is a global public health problem. For some subtypes, such as Claudin-low, the prognosis is poorer and the treatment is still a challenge. Pyrazoles are an important class of heterocyclic compounds and are promising anticancer agents based on their chemical properties. The present study was aimed not only at testing pyrazoles previously prepared by our research group in two breast cancer cell lines characterized by intermediated response to conventional chemotherapy but also at analyzing the possible synergistic effect of these pyrazoles associated with doxorubicin. Four 1-thiocarbamoyl-3,5-diaryl-4,5-dihydro-1H pyrazoles were tested for the first time in MCF-7 and MDA-MB-231 culture cells. The pyrazoles with best results in cytotoxicity were used in combination with doxorubicin and compared with this drug alone as standard. The synergic effect was analyzed using Combination Index method. In addition, cell death and apoptosis assays were carried out. Two pyrazoles with cytotoxic effect in MCF-7 and especially in MDA-MB-231 were identified. This activity was markedly higher in pyrazoles containing bromine and chlorine substituents. The combination of these pyrazoles with doxorubicin had a significant synergic effect in both cells tested and mainly in MDA-MB-231. These data were confirmed with apoptosis and cell death analysis. The synergic effect observed with combination of these pyrazoles and doxorubicin deserves special attention in Claudin-low breast cancer subtype. This should be explored in order to improve treatment results and minimize side effects. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. Pyrazole carboxamides and carboxylic acids as protein kinase inhibitors in aberrant eukaryotic signal transduction

    DEFF Research Database (Denmark)

    Persson, Tobias; Yde, Christina W.; Rasmussen, Jakob Ewald

    2007-01-01

    Densely functionalised pyrazole carboxamides and carboxylic acids were synthesised in an expedient manner through saponification and transamidation, respectively, of ester-functionalised pyrazoles. This synthetic protocol allowed for three diversifying steps in which appendages on the pyrazole...

  8. 4-Chloro­selanyl-3,5-diethyl-1H-pyrazol-2-ium chloride

    Science.gov (United States)

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

    2011-01-01

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

  9. Summary of diamino pyrazoles derived and study their biological activities

    International Nuclear Information System (INIS)

    Hagui, Marwa

    2016-01-01

    The work involves the synthesis of new heterocyclic structures diamino pyrazoles derivatives that are present in many natural products and products of pharmacological and therapeutic interests and study their biological activities. In order to develop a radiotracer interest and use in diagnostic nuclear medicine, we are interested to synthesis a pyrazole derivative with the precursor [Re(CO)5Br] and studying the antibacterial and antifungal activity of 3.5-diamino pyrazole and even thioamide complex rhenium. The objectives of our workout: 1/ Synthesis of molecules 3,5-diamino pyrazole and thioamide. 2/ Synthesis of 3,5-diamino pyrazole-rhenium complex. 3/ The in vitro study: Bacteriological Tests (Study of antibacterial and antifungal activity of 3,5-diamino pyrazole and thioamide). The first part of this work concerns the chemical synthesis of molecules such as: thioamide, Amp z1 Ampz2 and then we had synthesized the complex 3,5-diamino pyrazole-rhenium. Similarly we determined the physicochemical characteristics of the compounds synthesized by CLHP, CCM and RMN ( 1 H, 13 C). The second part is devoted to the study in vitro of biological activities of the synthesized molecules and complex 3,5 diaminopyrazole-rhenium with concentration 1 mg/mL and 2 mg/mL. The results allow us to say that the thioamide and Ampz2 have antibacterial activity against S. enterica and Ampz2 has low activity against S. aureus and P. aeruginossa. Other pyrazole derivatives have no significant antibacterial and antifungal activity. The results also show that the synthesized compounds of concentration 2 mg/mL in relation to the inhibition zones of amoxicillin and DMSO: 1/ Escherichia coli, there is antibacterial activity for thioamide, and the Amp z1-Re Ampz2 compound. 2/ Staphylococcus aureus, the complex Ampz 1-Re and the thioamide have significant antibacterial activity. 3/ Salmonella, we observe that the thioamide molecules, Ampz2 and Amp z1-Re have significant antibacterial activity

  10. 3,5-Dimethyl-4-nitroso-1H-pyrazole

    Directory of Open Access Journals (Sweden)

    Inna Safyanova

    2011-09-01

    Full Text Available In the unit cell of the title compound, C5H7N3O, there are two conformers (A and B which differ in the position of the oxime group with respect to the protonated pyrazole nitrogen (trans in the A conformer and cis in the B conformer and in the geometric parameters. The oxime group exists in the nitroso form in both conformers. In the crystal, molecules are linked by intermolecular N—H...O and N—H...N hydrogen bonds into zigzag-like chains along the b axis.

  11. Synthesis and Bioactivity of Pyrazole Acyl Thiourea Derivatives

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2012-05-01

    Full Text Available Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, 1H-NMR, 13C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests.

  12. Synthesis of spiro-4H-pyrazole-oxindoles and fused 1H-pyrazoles via divergent, thermally induced tandem cyclization/migration of alkyne-tethered diazo compounds.

    Science.gov (United States)

    Zhang, Cheng; Dong, Shanliang; Zheng, Yang; He, Ciwang; Chen, Jiaolong; Zhen, Jingsen; Qiu, Lihua; Xu, Xinfang

    2018-01-31

    A thermally induced, substrate-dependent reaction of alkynyl diazo compounds has been developed. This transformation produces spiro-4H-pyrazole-oxindoles and fused 1H-pyrazoles in good to high yields from the corresponding alpha-cyano and alpha-sulfonyl diazo compounds. The salient features of this reaction include excellent chemoselectivity and atom-economy, mild reaction conditions, simple purification and potential for large scale production.

  13. Ethyl 2-(3,4-dimethyl-5,5-dioxo-1H,4H-benzo[e]pyrazolo[4,3-c][1,2]thiazin-1-ylacetate

    Directory of Open Access Journals (Sweden)

    Sana Aslam

    2012-10-01

    Full Text Available In the title molecule, C15H17N3O4S, the heterocyclic thiazine ring adopts a twist-boat conformation, which differs from that in related compounds, with adjacent S and C atoms displaced by 0.981 (4 and 0.413 (5 Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean plane of the benzene ring makes a dihedral angle of 23.43 (14° with the mean plane of the pyrazole ring. In the crystal, molecules are connected by weak C—H...O hydrogen bonds to form a three-dimensional network. The H atoms of the methyl group attached to the pyrazole ring were refined over six sites with equal occupancies.

  14. 3,5-Dimethyl-4-nitroso-1H-pyrazole

    Science.gov (United States)

    Safyanova, Inna; Dudarenko, Nikolay M.; Pavlenko, Vadim A.; Iskenderov, Turganbay S.; Haukka, Matti

    2011-01-01

    In the unit cell of the title compound, C5H7N3O, there are two conformers (A and B) which differ in the position of the oxime group with respect to the protonated pyrazole nitro­gen (trans in the A conformer and cis in the B conformer) and in the geometric parameters. The oxime group exists in the nitroso form in both conformers. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O and N—H⋯N hydrogen bonds into zigzag-like chains along the b axis. PMID:22059058

  15. Synthesis, spectral characterization and X-ray crystal structure studies of 3-(benzo[d][1,3]dioxol-5-yl)-5-(3-methylthiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboxamide: Hirshfeld surface, DFT and thermal analysis

    Science.gov (United States)

    Kumara, Karthik; Dileep Kumar, A.; Naveen, S.; Ajay Kumar, K.; Lokanath, N. K.

    2018-06-01

    A novel pyrazole derivative, 3-(benzo[d][1,3]dioxol-5-yl)-5-(3-methylthiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboxamide was synthesized and characterized by elemental analysis, FT-IR, NMR (1H and 13C), MS, UV-visible spectra and finally the structure was confirmed by the single crystal X-ray diffraction studies. The title compound (C16H15N3O3S) crystallized in the triclinic crystal system, with the space group Pī. A dihedral angle of 65.84(1)° between the pyrazole and the thiophene rings confirms the twisted conformation between them. The X-ray structure revealed that the pyrazole ring adopts an E-form and an envelope conformation on C7 atom. The crystal and molecular structure of the title compound is stabilized by inter molecular hydrogen bonds. The compound possesses three dimensional supramolecular self-assembly, in which Csbnd H⋯O and Nsbnd H⋯O chains build up two dimensional arrays, which are extended to 3D network through Csbnd H···Cg and Csbnd O···Cg interactions. The structure also exhibits intramolecular hydrogen bonds of the type Nsbnd H⋯N and π···π stacking interactions, which contributes to the crystal packing. Further, Hirshfeld surface analysis was carried out for the graphical visualization of several short intermolecular interactions on the molecular surface while the 2D finger-print plot provides percentage contribution of each individual atom-to-atom interactions. The thermal decomposition of the compound has been studied by thermogravimetric analysis. The molecular geometries and electronic structures of the compounds were fully optimized, calculated with ab-initio methods by HF, DFT/B3LYP functional in combination of different basis set with different solvent environment and the structural parameters were compared with the experimental data. The Mulliken atomic charges and molecular electrostatic potential on molecular van der Waals (vdW) surface were calculated to know the electrophilic and nucleophilic regions

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-15

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

  17. Synthesis and structure of (bis(3,5-dimethyl-1H-pyrazol-1-yl)methane)diiodocobalt(II)

    International Nuclear Information System (INIS)

    Bushuev, M.B.; Virovets, A.V.; Peresypkina, E.V.; Naumov, D.Yu.; Lavrenova, L.G.; Potapov, A.S.; Khlebnikov, A.I.; Vasilevskij, S.F.

    2005-01-01

    Cobalt(II) iodo complex with bis(3,5-dimethyl-1H-pyrazol-1-yl)methane (L), CoLI 2 , is synthesized and its monocrystals are grown. The complex is characterized by electronic spectra and X-ray diffraction. CoLI 2 belongs to the monoclinic crystal system, sp. gr. P2 1 /m, a=8.4044(4), b=13.3120(5), c=14.5824(7) A; β=94.7290(10) deg; Z=4; d clcd =2.112 g/cm 3 . In its structure the complex is molecular and mononuclear one. Ligand L is coordinated in a bidentate-cyclic manner; the cobalt polyhedron is a CoN 2 I 2 tetrahedron formed by nitrogen atoms of the L pyrazole fragments and iodine atoms [ru

  18. QTAIM investigation of bis(pyrazol-1-ylmethane derivative and its Zn(II complexes (ZnLX2, X=Cl, Br or I

    Directory of Open Access Journals (Sweden)

    Dehestani Maryam

    2015-01-01

    Full Text Available Topological analyses of the electron density using the quantum theory of atoms in molecules (QTAIM have been carried out at the B3PW91/6-31g (d theoretical level, on bis(pyrazol-1-ylmethanes derivatives 9-(4-(di (1H-pyrazol-1-yl-methylphenyl-9H-carbazole (L and its zinc(II complexes: ZnLCl2 (1, ZnLBr2 (2 and ZnLI2 (3. The topological parameters derived from Bader theory were also analyzed; these are characteristics of Zn-bond critical points and also of ring critical points. The calculated structural parameters are the frontier molecular orbital energies highest occupied molecular orbital energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, hardness (η, softness (S, the absolute electronegativity (χ, the electrophilicity index (ω and the fractions of electrons transferred (ΔN from ZnLX2 complexes to L. The numerous correlations and dependencies between energy terms of the Symmetry Adapted Perturbation Theory approach (SAPT, geometrical, topological and energetic parameters were detected and described.

  19. Crystal structure of ethyl (2Z-2-cyano-3-[(3-methyl-1-phenyl-1H-pyrazol-5-ylamino]prop-2-enoate

    Directory of Open Access Journals (Sweden)

    Joel T. Mague

    2014-11-01

    Full Text Available The title compound, C16H16N4O2, crystallizes with two molecules in the asymmetric unit, one of which shows disorder of the acetate group over two sets of sites in a 0.799 (2:0.201 (2 ratio. The phenyl group has a similar but opposite sense of twist relative to the pyrazole ring in the two molecules, as indicated by the syn N—N—Car—Car (ar = aromatic torsion angles of 39.7 (2 and −36.9 (2°. Each molecule features an intramolecular N—H...O hydrogen bond, which closes an S(6 ring. In the crystal, C—H...O and C—H...N interactions direct the packing into a layered structure parallel to (110.

  20. X-ray structure, semi-empirical MO calculations and π-electron delocalization of 1-cyanoacetyl-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1 H-pyrazoles

    Science.gov (United States)

    Martins, Marcos A. P.; Moreira, Dayse N.; Frizzo, Clarissa P.; Campos, Patrick T.; Longhi, Kelvis; Marzari, Mara R. B.; Zanatta, Nilo; Bonacorso, Helio G.

    2010-04-01

    The structure of three 1-cyanoacetyl-3-alkyl[aryl]-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1 H-pyrazoles ( 1- 3) has been determined by X-ray diffractometry. The 4,5-dihydro-1 H-pyrazole rings were obtained as almost planar structures showing RMS deviation at a range of 0.0196-0.0736 Å. The data demonstrate that the molecular packing is dependent on the substituent present in each molecule. In addition, a computational investigation using semi-empirical AM1 and RM1 methods was performed in order to investigate the correlation between experimental and calculated geometrical parameters. The data obtained suggest that the structural data furnished by the AM1 method is in better agreement with those experimentally determined for the above compounds. An analysis of the π-electron delocalization by HOMA calculations indicate that there is a hyperconjugation effect in the imine group toward to phenyl group at ring 3-position of compound 2, and that this resonance effect decrease in compounds 1 and 3. In addition, it was showed that bond N(1) and C(6) do not have an amide character. Thus, the O(6)-C(6)-N(1)-N(2)-C(3) fragment is not completely delocalized mainly due to the low π-electron delocalization in N(1)-N(2) bond for all compounds.

  1. Solvent-free one-pot cyclization and acetylation of chalcones: Synthesis of some 1-acetyl pyrazoles and spectral correlations of 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones

    Directory of Open Access Journals (Sweden)

    G. Thirunarayanan

    2016-11-01

    Full Text Available One-pot synthesis of some 1N-acetyl pyrazoles including 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones has been achieved via solvent-free microwave irradiation using substituted chalcones, hydrazine hydrate and acetic anhydride in the presence of catalytic amount of fly-ash: PTS catalyst. The yield of these 1N-acetyl pyrazole derivatives is more than 75%. The synthesized 1N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νCN and CO (cm−1 frequencies, NMR chemical shifts (δ, ppm of Ha, Hb, Hc, CH3 protons, CN, CO and CH3 carbons of 1-(3-(3,4-dimethylphenyl-5-(substituted phenyl-4,5-dihydro-1H-pyrazole-1-yl ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses, the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.

  2. Ultrasound Promoted Synthesis of Bis(substituted pyrazol-4-ylcarbonyl-Substituted Thioureas

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2009-03-01

    Full Text Available A series of novel bis(substituted pyrazol-4-ylcarbonyl-substituted thioureas have been synthesized by the reactions of substituted pyrazol-4-ylcarbonyl isothiocyanates with different diamines under ultrasound irradiation and classical heating method at 20-25 °C. In general, substantial improvement in rates and modest yields increases were observed when reactions were carried out under sonication, compared with the classical heating method. The structures of these compounds have been elucidated by elemental and spectral (IR, 1H-NMR analysis.

  3. Acid catalyzed solvent free synthesis of new 1-acyl-4-benzhydryl substituted pyrazoles

    International Nuclear Information System (INIS)

    Sher, M.; Kausar, T.; Riaz, N.; Sharif, A.

    2016-01-01

    A convenient, cost effective and environmentally benign methodology has been developed, which delivered fourteen new 1-acyl-4-benzhyrdyl substituted pyrazole derivatives under solvent free conditions. Target compounds were synthesized in good to excellent yields simply by grinding reactants in a pestle and mortar with catalytic amount of conc. H/sub 2/SO/sub 4/. All the newly formed compounds were fully characterized with the help of detailed spectroscopic techniques including FTIR, NMR and GC-MS. (author)

  4. Noval 1-substituted-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazole derivatives: Synthesis and pharmacological activity

    Directory of Open Access Journals (Sweden)

    Sabir Hussain

    2015-05-01

    Full Text Available Several-1-carbothioamide-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 2a–d, 1-(pyridine-4-ylcarbonyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 3a–d, 1-(5-chloro-6-fluoro-1,3-benzothiazole-2-ylthiocarbamoyl-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 4a–d and 1-[(1,2,4-triazole-4-yl carbothioamide]-3,5-dimethyl-4-[(substituted phenyl diazenyl] pyrazoles 5a–d were synthesized. The structures of the newly synthesized compounds were supported by IR, 1H NMR and mass spectral data. These compounds were investigated for their, anti-inflammatory, analgesic, ulcerogenic, lipid peroxidation, antibacterial and antifungal activities. Some of the synthesized compounds showed potent anti-inflammatory activity along with minimal ulcerogenic effect and lipid peroxidation, compared to ibuprofen and flurbiprofen. Some of the tested compounds also showed moderate antimicrobial activity against tested bacterial and fungal strains.

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

    Science.gov (United States)

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

    2017-01-01

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

  6. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid Amides.

    Science.gov (United States)

    Du, Shijie; Tian, Zaimin; Yang, Dongyan; Li, Xiuyun; Li, Hong; Jia, Changqing; Che, Chuanliang; Wang, Mian; Qin, Zhaohai

    2015-05-08

    A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  7. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic Acid Amides

    Directory of Open Access Journals (Sweden)

    Shijie Du

    2015-05-01

    Full Text Available A series of novel 3-(difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-ylphenyl-3-(difluoro-methyl-1-methyl-1H-pyrazole-4-carboxamide (9m exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  8. Partial deletion of argininosuccinate synthase protects from pyrazole plus lipopolysaccharide-induced liver injury by decreasing nitrosative stress

    Science.gov (United States)

    Lu, Yongke; Leung, Tung Ming; Ward, Stephen C.

    2012-01-01

    Argininosuccinate synthase (ASS) is the rate-limiting enzyme in the urea cycle. Along with nitric oxide synthase (NOS)-2, ASS endows cells with the l-citrulline/nitric oxide (NO·) salvage pathway to continually supply l-arginine from l-citrulline for sustained NO· generation. Because of the relevant role of NOS in liver injury, we hypothesized that downregulation of ASS could decrease the availability of intracellular substrate for NO· synthesis by NOS-2 and, hence, decrease liver damage. Previous work demonstrated that pyrazole plus LPS caused significant liver injury involving NO· generation and formation of 3-nitrotyrosine protein adducts; thus, wild-type (WT) and Ass+/− mice (Ass−/− mice are lethal) were treated with pyrazole plus LPS, and markers of nitrosative stress, as well as liver injury, were analyzed. Partial ablation of Ass protected from pyrazole plus LPS-induced liver injury by decreasing nitrosative stress and hepatic and circulating TNFα. Moreover, apoptosis was prevented, since pyrazole plus LPS-treated Ass+/− mice showed decreased phosphorylation of JNK; increased MAPK phosphatase-1, which is known to deactivate JNK signaling; and lower cleaved caspase-3 than treated WT mice, and this was accompanied by less TdT-mediated dUTP nick end labeling-positive staining. Lastly, hepatic neutrophil accumulation was almost absent in pyrazole plus LPS-treated Ass+/− compared with WT mice. Partial Ass ablation prevents pyrazole plus LPS-mediated liver injury by reducing nitrosative stress, TNFα, apoptosis, and neutrophil infiltration. PMID:22052013

  9. Pyrazole Based Inhibitors against Enzymes of Staphylococcus aureus

    DEFF Research Database (Denmark)

    Jagadeesan, G.; Vijayakuma, Vinodhkumar; Palayam, Malathy

    2015-01-01

    agents. The current study focuses on molecular docking and dynamics studies of pyrazole derivatives against Nucleosidase and DNA gyrase B of Staphylococcus aureus. Molecular docking and dynamics studies reveal that some of these derivatives show better binding abilities than some of the current drugs...

  10. Crystal structure of 2-[(3aS,6R-3,3,6-trimethyl-3,3a,4,5,6,7-hexahydro-2H-indazol-2-yl]thiazol-4(5H-one

    Directory of Open Access Journals (Sweden)

    Abdellah N'ait Ousidi

    2016-03-01

    Full Text Available The title compound, C13H19N3OS, is a new thiazolidin-4-one derivative prepared and isolated as the pure (3aS,6R-diastereisomer from (R-thiosemicarbazone pulegone. It crystallized with two independent molecules (A and B in the asymmetric unit. The compound is composed of a hexhydroindazole ring system (viz. a five-membered dihydropyrazole ring fused to a cyclohexyl ring with a thiazole-4-one ring system attached to one of the pyrazole N atoms (at position 2. The overall geometry of the two molecules differs slightly, with the mean planes of the pyrazole and thiazole rings being inclined to one another by 10.4 (1° in molecule A and 0.9 (1° in molecule B. In the crystal, the A and B molecules are linked via C—H...O hydrogen bonds, forming slabs parallel to the ab plane. There are C—H...π interactions present within the layers, and between the layers, so forming a three-dimensional structure.

  11. Preparation of 5-acyl- and 5-aryl-substituted 1-(benzyloxy)pyrazoles via directed ortho-lithiation/transmetalation and palladium catalyzed cross- coupling

    DEFF Research Database (Denmark)

    Kristensen, Jesper Langgaard; Begtrup, M.; Vedsø, P.

    1998-01-01

    Palladium(0) catalyzed cross-coupling of 1-(benzyloxy)pyrazol-5-ylzinc halides 3a,b, prepared by transmetalation of 1-(benzyloxy)-5-lithiopyrazole (2), with acyl chlorides produced 5 acyl-1-(benzyloxy)pyrazoles 4a-d in high yields. Similar coupling of the pyrazol-5-ylzinc halide with amino-, hydr...

  12. Green One-pot Synthesis of Novel Polysubstituted Pyrazole Derivatives as Potential Antimicrobial Agents.

    Science.gov (United States)

    Beyzaei, Hamid; Motraghi, Zahra; Aryan, Reza; Zahedi, Mohammad Mehdi; Samzadeh-Kermani, Alireza

    2017-12-01

    Various biological properties of natural and synthetic pyrazole derivatives such as anti-inflammatory, antimicrobial, neuroprotective, anticonvulsant, antidepressant and anticancer activities encouraged us to propose a new, fast, green and eco-friendly procedure for the preparation of some novel 5-amino-3-(aryl substituted)-1-(2,4-dinitrophenyl)-1H-pyrazole-4-carbonitriles. They were efficiently synthesized via one-pot two-step process reaction of malononitrile, 2,4-dinitrophenylhydrazine and different benzaldehydes in deep eutectic solvent (DES) glycerol/potassium carbonate. The products yield and reaction times were considerably improved in the presence of applied DES. Antibacterial effects of all newly synthesized pyrazoles in comparison with several common antibiotics were evaluated against a variety of Gram-positive and Gram-negative pathogenic bacteria. In addition to, their inhibitory activities on three fungi were compared to some current antifungal agents. The moderate to good antimicrobial potentials particularly against fungi were observed in the major heterocyclic compounds according to the IZD, MIC, MBC and MFC results.

  13. Regioselective Synthesis of Some Pyrazole Scaffolds Attached to Benzothiazole and Benzimidazole Moieties

    Directory of Open Access Journals (Sweden)

    Nabila A. Kheder

    2014-01-01

    Full Text Available Condensation of 2-(benzothiazol-2-ylacetonitrile (1 or 2-(1-methyl-1H-benzimidazol-2-ylacetonitrile (2 with thiophene-2-carbaldehyde afforded the corresponding acrylonitrile derivatives 3 or 4, respectively. The 1,3-dipolar cycloaddition reaction of the acrylonitrile 3 or 4 with nitrile-imine 6 gave novel pyrazole derivatives pendant to benzothiazole and benzimidazole. The pyrazoline derivative 7 was converted into the corresponding pyrazole derivative 11 via thermal elimination of hydrogen cyanide upon heating in sodium ethoxide solution. The structures of the synthesized products were confirmed by IR, 1H NMR, and mass spectral techniques.

  14. SOCl2 catalyzed cyclization of chalcones: Synthesis and spectral studies of some bio-potent 1H pyrazoles

    Directory of Open Access Journals (Sweden)

    K. Ranganathan

    2014-05-01

    Full Text Available Some aryl-aryl 1H pyrazoles have been synthesised by cyclization of aryl chalcones and hydrazine hydrate in the presence of SOCl2. The yields of the pyrazoles are more than 85%. These pyrazoles are characterized by their physical constants and spectral data. The infrared, NMR spectral group frequencies of these pyrazolines have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses the effects of substituent on the spectral frequencies have been studied. The antimicrobial activities of all synthesised pyrazolines have been studied using Bauer-Kirby method. DOI: http://dx.doi.org/10.4314/bcse.v28i2.11

  15. Synthesis and in vitro biological evaluation of new pyrazole chalcones and heterocyclic diamides as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Sankappa Rai U.

    2015-05-01

    Full Text Available Synthesis and characterization of new heterocyclic pyrazole chalcones (4a–e and diamide (6a–e derivatives are described. Pyrazole chalcones were synthesized by the reaction of pyrazole aldehydes and suitable aromatic ketones. Diamides were synthesized by the reaction of phthalic acid and amines. Newly synthesized compounds were characterized by spectral studies and their biological activity was assessed in vitro using MCF-7 (human breast adenocarcinoma and HeLa (human cervical tumor cells cell lines. Few of the synthesized molecules inhibited the growth of the human breast cancer cell lines and human cervical tumor cell lines at low micromolar to nanomolar concentrations.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  17. Synthesis and fungicidal activity of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline.

    Science.gov (United States)

    Lei, Peng; Zhang, Xuebo; Xu, Yan; Xu, Gaofei; Liu, Xili; Yang, Xinling; Zhang, Xiaohe; Ling, Yun

    2016-01-01

    Take-all of wheat, caused by the soil-borne fungus Gaeumannomyces graminis var. tritici, is one of the most important and widespread root diseases. Given that take-all is still hard to control, it is necessary to develop new effective agrochemicals. Pyrazole derivatives have been often reported for their favorable bioactivities. In order to discover compounds with high fungicidal activity and simple structures, 1,2,3,4-tetrahydroquinoline, a biologically active group of natural products, was introduced to pyrazole structure. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized, and their fungicidal activities were evaluated. The bioassay results demonstrated that the title compounds displayed obvious fungicidal activities at a concentration of 50 μg/mL, especially against V. mali, S. sclerotiorum and G. graminis var. tritici. The inhibition rates of compounds 10d, 10e, 10h, 10i and 10j against G. graminis var. tritici were all above 90 %. Even at a lower concentration of 16.7 μg/mL, compounds 10d and 10e exhibited satisfied activities of 100 % and 94.0 %, respectively. It is comparable to that of the positive control pyraclostrobin with 100 % inhibition rate. A series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were synthesized and their structures were confirmed by (1)H NMR, (13)C NMR, IR spectrum and HRMS or elemental analysis. The crystal structure of compound 10g was confirmed by X-ray diffraction. Bioassay results indicated that all title compounds exhibited obvious fungicidal activities. In particular, compounds 10d and 10e showed comparable activities against G. graminis var. tritici with the commercial fungicide pyraclostrobin at the concentration of 16.7 μg/mL.Graphical abstractA series of pyrazole derivatives containing 1,2,3,4-tetrahydroquinoline were designed and synthesized. Bioassay results indicated that all these compounds exhibited obvious fungicidal activities.

  18. The investigation of the reactions of some pyrazole-3-carboxylic acids with various diamines and diols

    Directory of Open Access Journals (Sweden)

    Rahmi Kasımoğulları

    2012-06-01

    Full Text Available In this study, some new derivatives were synthesized of 4-benzoyl-1-(3-nitrophenyl-5-phenyl-1H-pyrazole-3-carboxylic acid (1 and 4-(ethoxycarbonyl-1-(3-nitrophenyl-5-phenyl-1H-pyrazole-3-carboxylic acid (2 that they were pyrazole carboxylic acid derivatives. Firstly, 1 and 2 reacted with SOCl2 to transform them into acyl chlorides (3, 4. Then various bis-carboxamide derivatives (5–8 were obtained from the reaction of 3 and 4 with various diamines and also a ;#946;-hydroxy ester (9 derivative was obtained from the reaction of 3 with ethylene glycol. The structures of synthesized compounds were elucidated with using FT-IR, 1H NMR, 13C NMR and elemental analysis methods.

  19. 2-[(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]indane-1,3-dione

    Directory of Open Access Journals (Sweden)

    Abdullah M. Asiri

    2011-02-01

    Full Text Available The title compound 2-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]-indane-1,3-dione (3 was synthesized in high yield by reaction of 3,5-dimethyl-1-phenyl-pyrazole-4-carbaldehyde and indane-1,3-dione in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and GC-MS spectral analysis.

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

    Science.gov (United States)

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

    2011-05-01

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

  1. Non-Classical Transformation of Benzendiazonium Hydrogen Sulfates. Access to 1,3-Dimethylisochromeno[4,3-c]pyrazol-5(1H-one, a Potential Benzodiazepine Receptor Ligand

    Directory of Open Access Journals (Sweden)

    Giuseppe Daidone

    2013-10-01

    Full Text Available The compound 2-((1,3-dimethyl-1H-pyrazol-5-yl(methylcarbamoylbenzene-diazonium hydrogen sulfate (10 was reacted with copper sulfate and sodium chloride, in the presence of ascorbic acid as reducing agent, to afford a mixture of the chlorinated epimers 4′-chloro-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (18 and (19, the epimers 4′-hydroxy-2,2′,5′-trimethyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (20 and (21, and N-(1,3-dimethyl-1H-pyrazol-5-ylbenzamide (22. Under the foregoing conditions, diazonium salt 10 affords neither the 2-chloro-N-(1,3-dimethyl-1H-pyrazol-5-yl-N-methylbenzamide (23 nor the tricyclic derivative 24, the classical products of the Sandmeyer and Pschorr reactions, respectively. Finally, by heating 20 at 210 °C the compound 1,3-dimethylisochromeno[4,3-c]pyrazol-5(1H-one (24 was obtained. The transformation under the above conditions of 2-((4-chloro-3-methyl-1-phenyl- 1H-pyrazol-5-yl(methylcarbamoylbenzendiazonium hydrogen sulphate (11 afforded 4′,4′-dichloro-2,5′-dimethyl-2′-phenyl-2′,4′-dihydrospiro[isoindoline-1,3′-pyrazol]-3-one (29 as the sole reaction product.

  2. Regio- and enantioselective synthesis of N-substituted pyrazoles by rhodium-catalyzed asymmetric addition to allenes.

    Science.gov (United States)

    Haydl, Alexander M; Xu, Kun; Breit, Bernhard

    2015-06-08

    The rhodium-catalyzed asymmetric N-selective coupling of pyrazole derivatives with terminal allenes gives access to enantioenriched secondary and tertiary allylic pyrazoles, which can be employed for the synthesis of medicinally important targets. The reaction tolerates a large variety of functional groups and labelling experiments gave insights into the reaction mechanism. This new methodology was further applied in a highly efficient synthesis of JAK 1/2 inhibitor (R)-ruxolitinib. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Directory of Open Access Journals (Sweden)

    Kirti Narang

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  5. Regioconvergent and Enantioselective Rhodium-Catalyzed Hydroamination of Internal and Terminal Alkynes: A Highly Flexible Access to Chiral Pyrazoles.

    Science.gov (United States)

    Haydl, Alexander M; Hilpert, Lukas J; Breit, Bernhard

    2016-05-04

    The rhodium-catalyzed asymmetric N-selective coupling of pyrazole derivatives with internal and terminal alkynes features an utmost chemo-, regio-, and enantioselective access to enantiopure allylic pyrazoles, readily available for incorporation in small-molecule pharmaceuticals. This methodology is distinguished by a broad substrate scope, resulting in a remarkable compatability with a variety of different functional groups. It furthermore exhibits an intriguing case of regio-, position-, and enantioselectivity in just one step, underscoring the sole synthesis of just one out of up to six possible products in a highly flexible approach to allylated pyrazoles by emanating from various internal and terminal alkynes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  7. Preparation of 3,5-disubstituted pyrazoles and isoxazoles from terminal alkynes, aldehydes, hydrazines, and hydroxylamine.

    Science.gov (United States)

    Harigae, Ryo; Moriyama, Katsuhiko; Togo, Hideo

    2014-03-07

    The reaction of terminal alkynes with n-BuLi, and then with aldehydes, followed by the treatment with molecular iodine, and subsequently hydrazines or hydroxylamine provided the corresponding 3,5-disubstituted pyrazoles or isoxazoles in good yields with high regioselectivity, through the formations of propargyl secondary alkoxides and α-alkynyl ketones. The present reactions are one-pot preparation of 3,5-disubstituted pyrazoles from terminal alkynes, aldehydes, molecular iodine, and hydrazines, and 3,5-disubstituted isoxazoles from terminal alkynes, aldehydes, molecular iodine, and hydroxylamine.

  8. Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand.

    Science.gov (United States)

    Vafazadeh, Rasoul; Willis, Anthony C

    2016-01-01

    Two copper(II) clusters Cu(4)OCl(6)(pyrazole)4, 1, and Cu(4)OBr(6)(Br-pyrazole)4, 2, have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio) with CuX(2) (X = Cl for 1 and X= Br for 2) in methanol solutions. The structures of both clusters have been established by X-ray crystallography. The clusters contain four Cu, one O, six μ(2)-X atoms, and four pyrazole ligands. The pyrazoles was prepared in situ by the reaction of acetylacetone with benzohydrazide in methanol under reflux. In 2, the methine hydrogens of the pyrazole ligands have been replaced by bromine atoms. The four copper atoms encapsulate the central O atom in a tetrahedral arrangement. All copper atoms are five-coordinate and have similar coordination environments with slightly distorted trigonal bipyramidal geometry. The cyclic voltammogram of the clusters 1 and 2 show a one-electron quasi-reversible reduction wave in the region 0.485 to 0.731 V, and a one-electron quasi-reversible oxidation wave in the region 0.767 to 0.898 V. In 1, one irreversible oxidative response is observed on the positive of side of the voltammogram at 1.512 V and this can be assigned to Cu(II) to Cu(III) oxidation.

  9. Synthesis and structure of a ferric complex of 2,6-di(1H-pyrazol-3-yl)pyridine and its excellent performance in the redox-controlled living ring-opening polymerization of ε-caprolactone.

    Science.gov (United States)

    Fang, Yang-Yang; Gong, Wei-Jie; Shang, Xiu-Juan; Li, Hong-Xi; Gao, Jun; Lang, Jian-Ping

    2014-06-14

    The reaction of FeCl3 with a pincer ligand, 2,6-di(1H-pyrazol-3-yl)pyridine (bppyH2), produced a mononuclear Fe(III) complex [Fe(bppyH2)Cl3] (1), which could be reduced to the corresponding Fe(II) dichloride complex [Fe(bppyH2)Cl2] (2) by suitable reducing agents such as Cp2Co or Fe powder. 1 and 2 exhibited a reversible transformation from each other with appropriate redox reagents. 1 could be utilized as a pre-catalyst to initiate the ring-opening polymerization of ε-caprolactone in the presence of alcohol but did not work. The 1/alcohol system displayed characteristics of a well-controlled polymerization with the resulting poly(ε-caprolactone) having low molecular weight distributions, a linear tendency of molecular weight evolution with conversion, and polymer growth observed for the sequential additions of ε-caprolactone monomer to the polymerization reaction. The polymerization was completely turned off by the in situ reduction of the catalytic Fe center via Cp2Co and then turned back upon the addition of [Cp2Fe]PF6. The rate of polymerization was modified by switching in situ between the Fe(III) and Fe(II) species.

  10. 4,4-Dimethyl-3,4-dihydropyrido[2′,3′:3,4]pyrazolo[1,5-a][1,3,5]triazin-2-amine ethanol monosolvateFused heterocyclic systems with s-triazine ring. Part 16. for part 15, see Sachdeva et al. (2010.

    Directory of Open Access Journals (Sweden)

    Lip Lin Koh

    2011-01-01

    Full Text Available In the title compound, C10H12N6·C2H5OH, the planarity of the heterocyclic system is slightly distorted at the triazine ring (r.m.s. deviation = 0.1191 Å, which adopts a conformation best described as intermediate between a flattened twisted boat and a half-boat with the tertiary Csp3 atom at the bow. In the crystal, molecules form centrosymmetric dimers connected by N...H—O and O...H—N hydrogen bonds between the amino group H atom, the ethanol solvent molecule and the triazine N atom, making an R44(12 graph-set motif. The other H atom of the amino group and the H atom on the endocyclic N atom form N...H—N hydrogen bonds with the N atoms of the pyrazole and pyridine rings, respectively, linking the molecules into C(7C(7 chains with the R22(8 binary graph-set motif running along [010].

  11. Synthesis and antimicrobial screening of novel 2-(5-(4-(allyloxy-3-methoxyphenyl-1H-pyrazol-3-ylphenols analogues of 2-(4-(allyloxy-3-methoxyphenyl-4H-chromen-4-ones

    Directory of Open Access Journals (Sweden)

    Asha V. Chate

    2012-01-01

    Full Text Available A series of novel 2-(5-(4-(allyloxy-3-methoxyphenyl-1H-pyrazol-3-ylphenols derivatives have been synthesized via the ring opening of 2-(4-(allyloxy-3-methoxyphenyl-4H-chromen-4-ones in ethanol and hydrazine hydrate under reflux condition. The synthesized compounds were screened for antibacterial and antifungal activity against bacteria Staphylococcus aureus (MRSA E710 and Escherichia coli (ATCC 25922 and fungi Candida albicans and Aspergillus fumigates respectively. Some of the tested compounds showed significant antimicrobial activity. 1H NMR, IR, Mass spectral data and elemental analysis elucidated the structures of the all newly synthesized compounds.

  12. Synthesis and characterization of some complexes with imidazole and pyrazole from saccharinate transition ions in oxidation state (II)

    International Nuclear Information System (INIS)

    Pineda Cedeno, Leslie William

    2001-01-01

    The synthesis and characterization of metal ions saccharinate of the first serie of transition with the imidazole and pyrazole molecules in water and absolute ethanol were studied. In general, it found that in this series of saccharinate of coordinated water molecules are replaced by imidazole and pyrazole molecules with different substitution patterns, generating neutral complex of molecular formula [M(Sac) 2 (L) n (H 2 O) n-4 ] and cationic complex of molecular formula [M(L) n (H 2 O) 2 ]x2Sac, [M(L) n (H 2 O) 3 ]x2Sac, [M(L) n ]x2Sac, where M = V(II), Cr(II), Mc(II), Fe(II), Co(II), Ni(II) y Zn(II); Sac = saccharinate ion; L = imidazole (imd) and pyrazole (pir) and n = 6,4,3 and 2. These compounds are soluble in DMF and insoluble in all other common solvents. In turn, synthesized compounds in water were characterized by X ray crystallography, where preliminary data of refinement cycles, generate formulas of isostructural type [M(imd) 4 (H 2 O) 2 ]x2Sac and [M(Sac) 2 (pir) 2 (H 2 O) 2 ] where M = Co(II), Ni(II). The imidazole complex crystallize in the triclinic crystal system and space group P-1, while the pyrazole complexes crystallize in the monoclinic crystal system and space group P2 (1)/n. Gradual diminution was observed in the bond distances of M-N (saccharinate ion), M-N (imidazole) and M-N (pyrazole). The complex was characterized by spectroscopic methods, magnetic and electrochemical. (author) [es

  13. Novel One-Pot Access to 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl) indolin-2-ones

    International Nuclear Information System (INIS)

    Lin, Y.; Fu, Z.; Song, Q.; Shen, T.

    2016-01-01

    Sodium bicarbonate was applied as catalyst for the synthesis of 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl)indolin-2-ones via the reaction of isatins, hydrazine hydrate and ethyl acetoacetate or ethyl benzoylacetate. This reaction was performed in ethanol at 78 degree C, giving 3,3-bis(3-hydroxy-5-substituted-1H-pyrazol-4-yl)indolin-2-one derivatives in good to excellent yields. The structure of 5-bromo-3,3-bis(3-hydroxy-5-methyl-1H-pyrazol-4-yl) indolin-2-one was unambiguously confirmed by X-ray single crystal structure analysis and a plausible reaction mechanism is also proposed. (author)

  14. DFT, FT-IR, FT-Raman and NMR studies of 4-(substituted phenylazo)-3,5-diacetamido-1H-pyrazoles

    Science.gov (United States)

    Kınalı, Selin; Demirci, Serkan; Çalışır, Zühre; Kurt, Mustafa; Ataç, Ahmet

    2011-05-01

    We present a detailed analysis of the structural and vibrational spectra of some novel azo dyes. 2-(Substituted phenylazo)malononitriles were synthesized by the coupling reaction of the diazonium salts, which were prepared with the use of various aniline derivatives with malononitrile, and then 4-(substituted phenylazo)-3,5-diamino-1H-pyrazole azo dyes were obtained via the ring closure of the azo compounds with hydrazine monohydrate. The experimental and theoretical vibrational spectra of azo dyes were studied. The structural and spectroscopic analysis of the molecules were carried out by using Becke's three-parameters hybrid functional (B3LYP) and density functional harmonic calculations. The 1H nuclear magnetic resonance (NMR) chemical shifts of the azo dye molecules were calculated using the gauge-invariant-atomic orbital (GIAO) method. The calculated vibrational wavenumbers and chemical shifts were compared with the experimental data of the molecules.

  15. Candidate PET radioligands for cannabinoid CB{sub 1} receptors: [{sup 18}F]AM5144 and related pyrazole compounds

    Energy Technology Data Exchange (ETDEWEB)

    Zizhong, Li [Center for Translational Neuroimaging, Brookhaven National Laboratory, Upton, NY 11973 (United States); Gifford, Andrew [Center for Translational Neuroimaging, Brookhaven National Laboratory, Upton, NY 11973 (United States); Qian, Liu [Center for Drug Discovery, Northeastern University, Boston, MA 02115 (United States); Thotapally, Rajesh [Center for Drug Discovery, Northeastern University, Boston, MA 02115 (United States); Yushin, Ding [Center for Translational Neuroimaging, Brookhaven National Laboratory, Upton, NY 11973 (United States); Makriyannis, Alexandros [Center for Drug Discovery, Northeastern University, Boston, MA 02115 (United States); Gatley, S John [Center for Translational Neuroimaging, Brookhaven National Laboratory, Upton, NY 11973 (United States) and Center for Drug Discovery, Northeastern University, Boston, MA 02115 (United States)

    2005-05-01

    Introduction: The mammalian brain contains abundant G protein-coupled cannabinoid CB{sub 1} receptors that respond to {delta}{sup 9}-tetrahydrocannabinol, the active ingredient of cannabis. The availability of a positron emission tomography (PET) radioligand would facilitate studies of the addictive and medicinal properties of compounds that bind to this receptor. Among the known classes of ligands for CB{sub 1} receptors, the pyrazoles are attractive targets for radiopharmaceutical development because they are antagonists and are generally less lipophilic than the other classes. Methods: A convenient high-yield synthesis of N-(4-[{sup 18}F]fluorophenyl)-5-(4-bromophenyl)-1-(2,4-dichlorophenyl)- 1H-pyrazole-3-carboxamide (AM5144) was devised by coupling the appropriate pyrazole-3-carboxyl chloride compound with 4-[{sup 18}F]fluoroaniline. The labeled precursor was synthesized from 1-[{sup 18}F]fluoro-4-nitrobenzene in 60% radiochemical yield for 10 min using an improved procedure involving sodium borohydride reduction with cobalt chloride catalysis. The product was purified by HPLC to give a specific activity >400 mCi/{mu}mol and a radiochemical purity >95%, and a PET study was conducted in a baboon. Results: Although the regional uptake of AM5144 in baboon brain was consistent with binding to cannabinoid CB{sub 1} receptors, absolute uptake at <0.003% injected radioactivity per cubic centimeter was lower than the previously reported uptake of the radioiodinated pyrazole AM281. Conclusions: The relatively poor brain uptake of AM5144 and other pyrazole CB{sub 1} receptor ligands is not surprising because of their high lipophilicity as compared with most brain PET radiotracers. However, for nine pyrazole compounds for which rodent data are available, brain uptake and calculated logP values are not correlated. Thus, high logP values should not preclude evaluation of radiotracers for targets such as the CB{sub 1} receptor that may require very lipophilic ligands.

  16. Transition metal complexes with pyrazole-based ligands.Part 29. Reactions of zinc(II and mercury(II thiocyanate with 4-acetyl-3-amino-5-methylpyrazole

    Directory of Open Access Journals (Sweden)

    KATALIN MÉSZÁROS SZÉCSÉNYI

    2009-11-01

    Full Text Available The work is concerned with the crystal and molecular structures of zinc(II and mercury(II complexes with 4-acetyl-3-amino-5-methyl-pyrazole (aamp of the coordination formulae [Zn(NCS2(aamp2] and (Haamp2[Hg(SCN4]. The zinc(II complex was obtained by the reaction of a warm methanolic solution of aamp with a mixture of zinc(II nitrate and ammonium thiocyanate, whereas the mercury(II complex was prepared by the reaction of a warm ethanolic solution of aamp and a warm, slightly acidified aqueous solution of [Hg(SCN4]2-. Both complexes have a tetrahedral geometry, which in the case of zinc complex is formed by monodentate coordination of two aamp molecules and two isothiocyanate groups. The Zn(II and Hg(II atoms have significantly deformed coordination geometry. In both crystal structures the pyrazole derivative has a planar form, probably stabilized by an intramolecular N–H···O hydrogen bond. Apart from the X-ray structural analysis, the isolated complexes were characterized by elemental analysis, IR spectroscopy, conductometric measurements and thermal analysis.

  17. 1-Allyl-3-amino-1H-pyrazole-4-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Feng-Ling Yang

    2008-12-01

    Full Text Available The title compound, C7H9N3O2, was prepared by alkaline hydrolysis of ethyl 1-allyl-3-amino-1H-pyrazole-4-carboxylate. The crystal structure is stabilized by three types of intermolecular hydrogen bond (N—H...O, N—H...N and O—H...N.

  18. Tert-butyl 3-oxo-2,3,4,5,6,7-hexahydro-1H-pyrazolo[4,3-c]pyridine-5-carboxylate

    Directory of Open Access Journals (Sweden)

    Tara Shahani

    2010-01-01

    Full Text Available In the title compound, C11H17N3O3, the pyrazole ring is approximately planar, with a maximum deviation of 0.005 (2 Å, and forms a dihedral angle of 5.69 (13° with the plane through the six atoms of the piperidine ring. In the crystal, pairs of intermolecular N—H...O hydrogen bonds form dimers with neighbouring molecules, generating R22(8 ring motifs. These dimers are further linked into two-dimensional arrays parallel to the bc plane by intermolecular N—H...O and C—H...O hydrogen bonds.

  19. In vitro biological characterization of a novel, synthetic diaryl pyrazole resorcinol class of heat shock protein 90 inhibitors.

    Science.gov (United States)

    Sharp, Swee Y; Boxall, Kathy; Rowlands, Martin; Prodromou, Chrisostomos; Roe, S Mark; Maloney, Alison; Powers, Marissa; Clarke, Paul A; Box, Gary; Sanderson, Sharon; Patterson, Lisa; Matthews, Thomas P; Cheung, Kwai-Ming J; Ball, Karen; Hayes, Angela; Raynaud, Florence; Marais, Richard; Pearl, Laurence; Eccles, Sue; Aherne, Wynne; McDonald, Edward; Workman, Paul

    2007-03-01

    The molecular chaperone heat shock protein 90 (HSP90) has emerged as an exciting molecular target. Derivatives of the natural product geldanamycin, such as 17-allylamino-17-demethoxy-geldanamycin (17-AAG), were the first HSP90 ATPase inhibitors to enter clinical trial. Synthetic small-molecule HSP90 inhibitors have potential advantages. Here, we describe the biological properties of the lead compound of a new class of 3,4-diaryl pyrazole resorcinol HSP90 inhibitor (CCT018159), which we identified by high-throughput screening. CCT018159 inhibited human HSP90beta with comparable potency to 17-AAG and with similar ATP-competitive kinetics. X-ray crystallographic structures of the NH(2)-terminal domain of yeast Hsp90 complexed with CCT018159 or its analogues showed binding properties similar to radicicol. The mean cellular GI(50) value of CCT018159 across a panel of human cancer cell lines, including melanoma, was 5.3 mumol/L. Unlike 17-AAG, the in vitro antitumor activity of the pyrazole resorcinol analogues is independent of NQO1/DT-diaphorase and P-glycoprotein expression. The molecular signature of HSP90 inhibition, comprising increased expression of HSP72 protein and depletion of ERBB2, CDK4, C-RAF, and mutant B-RAF, was shown by Western blotting and quantified by time-resolved fluorescent-Cellisa in human cancer cell lines treated with CCT018159. CCT018159 caused cell cytostasis associated with a G(1) arrest and induced apoptosis. CCT018159 also inhibited key endothelial and tumor cell functions implicated in invasion and angiogenesis. Overall, we have shown that diaryl pyrazole resorcinols exhibited similar cellular properties to 17-AAG with potential advantages (e.g., aqueous solubility, independence from NQO1 and P-glycoprotein). These compounds form the basis for further structure-based optimization to identify more potent inhibitors suitable for clinical development.

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

    International Nuclear Information System (INIS)

    Wolski, Andrzej; Woodley, Mark D.

    2004-01-01

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

  1. Standard molar enthalpies of formation of three methyl-pyrazole derivatives

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Cabral, Joana I.T.A.

    2012-01-01

    Highlights: ► Combustion calorimetry was used to determine Δ f H m ∘ (cr) of methyl-pyrazole derivatives. ► Vapour pressures were determined by the Knudsen mass-loss effusion technique. ► Gas-phase Δ f H m ∘ of the studied compounds have been derived. - Abstract: The standard (p ° = 0.1 MPa) molar enthalpies of formation of the crystalline 3-methyl-1-pyrazolecarboxamide; 3-methyl-3-pyrazoline-5-one; and 4-methyl-2-pyrazoline-5-one were derived from the standard massic energies of combustion, in oxygen, to yield CO 2 (g), H 2 O (l) and N 2 (g), at T = 298.15 K, measured by static bomb combustion calorimetry. The standard molar enthalpies of sublimation were calculated from the variation of the vapour pressures of each compound with temperature, measured by the Knudsen effusion technique. These two thermodynamic parameters yielded the standard molar enthalpies of formation of the pyrazole derivatives, in the gaseous phase, at T = 298.15 K. The derived standard molar enthalpies of formation, in gaseous state, are analyzed in terms of enthalpic increments and interpreted in terms of molecular structure.

  2. Synthesis of Functionalized Pyrazoles via 1,3-Dipolar Cycloaddition of α-Diazo-β-ketophosphonates, Sufones and Esters with Electron-Deficient Alkenes.

    Science.gov (United States)

    Baiju, T V; Namboothiri, Irishi N N

    2017-10-01

    1,3-Dipolar cycloaddition of diazo compounds with olefinic substrates is a promising atom-economic strategy for the construction of functionalized pyrazoles. Over the last few years, our group has been engaged in the synthesis of phosphonyl/sulfonylpyrazoles and pyrazole esters by employing Bestmann-Ohira Reagent (BOR) and its sulfur and ester analogs as 1,3-dipole precursors with various dipolarophiles. This account describes the novel synthetic methods developed in our laboratory, in the perspective of closely related work by others, for the synthesis of phosphonyl/sulfonylpyrazoles, pyrazole esters and the total synthesis of Withasomnine, a natural product, by using 1,3-dipolar cycloaddition as the key step. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. An Efficient Synthesis of Novel Pyrazole-Based Heterocycles as Potential Antitumor Agents

    Directory of Open Access Journals (Sweden)

    Magda A. Abdallah

    2017-08-01

    Full Text Available A new series of pyrazolylpyridines was prepared by reaction of ethyl-3-acetyl-1,5-diphenyl-1H-pyrazole-4-carboxylate with the appropriate aldehyde, malononitrile, or ethyl acetoacetate and an excess of ammonium acetate under reflux in acetic acid. Similarly, two novel bipyridine derivatives were prepared by the above reaction using terephthaldehyde in lieu of benzaldehyde derivatives. In addition, a series of 1,2,4-triazolo[4,3-a]pyrimidines was synthesized by a reaction of 6-(pyrazol-3-ylpyrimidine-2-thione with a number of hydrazonoyl chlorides in dioxane and in the presence of triethylamine. The structure of the produced compounds was established by elemental analyses and spectral methods, and the mechanisms of their formation was discussed. Furthermore, the pyrazolyl-pyridine derivatives were tested as anticancer agents and the results obtained showed that some of them revealed high activity against human hepatocellular carcinoma (HEPG2 cell lines.

  4. Synthesis, basicity and complex properties from A ZN (II) of a acyclic purazol and pyridine proton-ionizable new receptor; Sintesis, basicidad y propiedades complejantes frente a Zn(II) de un nuevo receptor aciclico de pirazol y piridina prton-ionizable

    Energy Technology Data Exchange (ETDEWEB)

    Bueno, J.M.; Campayo, L.; Navarro, P.; Acerete, C. [Instituto de Quimica Medica CSIC, Madrid (Spain)

    1995-12-01

    The synthesis of bis (2`-pyridylmethil) N{sub 1}-H pyrazole 3,5-dicarboxylate 1[L] is reported. The formation of its sodium pyrazolate salt 1` [L] has been studied by ``13 CNMR, and the deprotonation pKa value of the pyrazole ring of 1 and those corresponding to the protonation of their pyridine rings have been measured using potentiometric methods in H{sub 2}O-MeOH (v/v 9:1) Starting from 1[L] or 1`[L-], the formation of mono- and di-nuclear complexes 2Zn[L] and 3[Zn{sub 2}[L-

  5. Candidate PET radioligands for cannabinoid CB1 receptors: [18F]AM5144 and related pyrazole compounds

    International Nuclear Information System (INIS)

    Li Zizhong; Gifford, Andrew; Liu Qian; Thotapally, Rajesh; Ding Yushin; Makriyannis, Alexandros; Gatley, S. John

    2005-01-01

    Introduction: The mammalian brain contains abundant G protein-coupled cannabinoid CB 1 receptors that respond to Δ 9 -tetrahydrocannabinol, the active ingredient of cannabis. The availability of a positron emission tomography (PET) radioligand would facilitate studies of the addictive and medicinal properties of compounds that bind to this receptor. Among the known classes of ligands for CB 1 receptors, the pyrazoles are attractive targets for radiopharmaceutical development because they are antagonists and are generally less lipophilic than the other classes. Methods: A convenient high-yield synthesis of N-(4-[ 18 F]fluorophenyl)-5-(4-bromophenyl)-1-(2,4-dichlorophenyl)- 1H-pyrazole-3-carboxamide (AM5144) was devised by coupling the appropriate pyrazole-3-carboxyl chloride compound with 4-[ 18 F]fluoroaniline. The labeled precursor was synthesized from 1-[ 18 F]fluoro-4-nitrobenzene in 60% radiochemical yield for 10 min using an improved procedure involving sodium borohydride reduction with cobalt chloride catalysis. The product was purified by HPLC to give a specific activity >400 mCi/μmol and a radiochemical purity >95%, and a PET study was conducted in a baboon. Results: Although the regional uptake of AM5144 in baboon brain was consistent with binding to cannabinoid CB 1 receptors, absolute uptake at 1 receptor ligands is not surprising because of their high lipophilicity as compared with most brain PET radiotracers. However, for nine pyrazole compounds for which rodent data are available, brain uptake and calculated logP values are not correlated. Thus, high logP values should not preclude evaluation of radiotracers for targets such as the CB 1 receptor that may require very lipophilic ligands

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-20

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

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

    International Nuclear Information System (INIS)

    Väisänen, Petri; Barway, Sudhanshu; Randriamanakoto, Zara

    2014-01-01

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

  8. Succinic acid dihydrazide: a convenient N,N-double block for the synthesis of symmetrical and non-symmetrical succinyl-bis[5-trifluoro(chloro)methyl-1H-pyrazoles

    International Nuclear Information System (INIS)

    Bonacorso, Helio G.; Cechinel, Cleber A.; Pittaluga, Everton P.; Ferla, Adriana; Porte, Liliane M.F; Martins, Marcos A.P; Zanatta, Nilo

    2010-01-01

    This paper describes the conventional regioselective synthesis of a series of new succinyl spacer bis-(3,5-substituted 2-pyrazolines and 1H-pyrazoles), namely; 1,4-bis[5-(trifluoromethyl)-5- hydroxy-4,5-dihydro-1H-pyrazol-1-yl]butane-1,4-diones (46-88%) and the respective dehydrated system (60-78%), new 1-[5-(trifluoromethyl)-5-hydroxy-4,5-dihydro-1H-pyrazol-1-yl]-4- oxobutane hydrazides (52-81%) and the non-symmetrical 2-pyrazolines derivatives thereof as 1-[5-(trifluoromethyl)- 5-hydroxy-4,5-dihydro-1H-pyrazol-1-yl)-4-(5-(trichloromethyl)-5-hydroxy- 4,5-dihydro-1H-pyrazol-1-yl]butane-1,4-diones (75-91%). All succinyl substituted bispyrazoles were obtained from the cyclocondensation reactions of 4-substituted 4-alkoxy-1,1,1-trihaloalk-3- en-2-ones, where the 4-substituents are H, Me, Ph, 4-FC 6 H 4 , 4-ClC 6 H 4 , 4-OMeC 6 H 4 , 4-NO 2 C 6 H 4 , 1-naphthyl and 2-furyl, with succinic acid dihydrazide in ethanol as solvent under controlled reaction conditions. (author)

  9. Combining silver- and organocatalysis: an enantioselective sequential catalytic approach towards pyrano-annulated pyrazoles.

    Science.gov (United States)

    Hack, Daniel; Chauhan, Pankaj; Deckers, Kristina; Mizutani, Yusuke; Raabe, Gerhard; Enders, Dieter

    2015-02-11

    A one-pot asymmetric Michael addition/hydroalkoxylation sequence, catalyzed by a sequential catalytic system consisting of a squaramide and a silver salt, provides a new series of chiral pyrano-annulated pyrazole derivatives in excellent yields (up to 95%) and high enantioselectivities (up to 97% ee).

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  11. New 2-Methoxy Acetylenic Acids and Pyrazole Alkaloids from the Marine Sponge Cinachyrella sp.

    Directory of Open Access Journals (Sweden)

    Amin Mokhlesi

    2017-11-01

    Full Text Available Three new 2-methoxy acetylenic acids (1–3 and a known derivative (4, in addition to three new natural pyrazole alkaloids (5–7 were isolated from an Indonesian marine sponge of the genus Cinachyrella. Compounds 5 and 6 have previously been reported as synthetic compounds. The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopy as well as by mass spectrometric data. The absolute configuration of the new acetylenic acid derivatives (1–3 was established by ECD spectroscopy. All isolated compounds were evaluated for their cytotoxicity against L5178Y mouse lymphoma cells. Compounds 1–4 exhibited strong activity with an IC50 value of 0.3 µM. A plausible biosynthetic pathway for the pyrazole metabolites 5–7 is proposed.

  12. Molecular Self-Assembly of Group 11 Pyrazolate Complexes as Phosphorescent Chemosensors for Detection of Benzene

    Science.gov (United States)

    Ghazalli, N. F.; Yuliati, L.; Lintang, H. O.

    2018-01-01

    We highlight the systematic study on vapochromic sensing of aromatic vapors such as benzene using phosphorescent trinuclear pyrazolate complexes (2) with supramolecular assembly of a weak intermolecular metal-metal interaction consisting of 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligand (1) and group 11 metal ions (Cu(I), Ag(I), Au(I)). The resulting chemosensor 2(Cu) revealed positive response to benzene vapors in 5 mins by blue-shifting its emission band in 44 nm (from 616 to 572 nm) and emitted bright orange to green, where this change cannot be recovered even with external stimuli. Comparing to 2(Ag) with longer metal-metal distance (473 nm) with same sensing time and quenching in 37%, 2(Au) gave quenching in 81% from its original intensity at 612 nm with reusability in 82% without external stimuli and emitted less emissive of red-orange from its original color. The shifting phenomenon in 2(Cu) suggests diffusion of benzene vapors to inside molecules for formation of intermolecular interaction with Cu(I)-Cu(I) interaction while quenching phenomenon in 2(Au) suggests diffusion of benzene vapors to between the Au(I)-Au(I) interaction. These results indicate that suitable molecular structure of ligand and metal ion in pyrazolate complex is important for designing chemosensor in the detection of benzene vapors.

  13. Synthesis and Bioactivities of Novel Pyrazole Oxime Derivatives Containing a 5-Trifluoromethylpyridyl Moiety

    Directory of Open Access Journals (Sweden)

    Hong Dai

    2016-02-01

    Full Text Available In this study, in order to find novel biologically active pyrazole oxime compounds, a series of pyrazole oxime derivatives containing a 5-trifluoromethylpyridyl moiety were synthesized. Preliminary bioassays indicated that most title compounds were found to display good to excellent acaricidal activity against Tetranychus cinnabarinus at a concentration of 200 μg/mL, and some designed compounds still showed excellent acaricidal activity against Tetranychus cinnabarinus at the concentration of 10 μg/mL, especially since the inhibition rates of compounds 8e, 8f, 8l, 8m, 8n, 8p, and 8q were all 100.00%. Interestingly, some target compounds exhibited moderate to good insecticidal activities against Plutella xylostella and Aphis craccivora at a concentration of 200 μg/mL; furthermore, compounds 8e and 8l possessed outstanding insecticidal activities against Plutella xylostella under the concentration of 50 μg/mL.

  14. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

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

  15. Synthesis of new derivatives of 1-(3-aminophenyl-4-benzoyl-5-phenyl-1H-pyrazole-3-carboxylic acid

    Directory of Open Access Journals (Sweden)

    RAHMI KASIMOGULLAR

    2010-12-01

    Full Text Available 1-(3-Aminophenyl-4-benzoyl-5-phenyl-1H-pyrazole-3-carboxylic acid (1 was synthesized according to the literature. 2-(3-Aminophenyl-2,6-dihydro-3,4-diphenyl-7H-pyrazolo[3,4-d]pyridazin-7-one (5 was obtained by the cyclocondensation reaction of 1 with hydrazine hydrate. New pyrazole derivatives of compounds 1 and 5 were synthesized by their reaction with β-diketones, β-ketoesters, β-naphthol, phenol and various other reagents. The structures of the synthesized compounds were characterized by 1H-NMR, 13C-NMR, IR and mass spectroscopy, as well as elemental analysis.

  16. Bis[tris(1H-pyrazol-1-yl-κN2methane]nickel(II bis{[tris(1H-pyrazol-1-yl-κN2methane]tris(thiocyanato-κNnickelate(II} methanol disolvate

    Directory of Open Access Journals (Sweden)

    Ganna Lyubartseva

    2011-12-01

    Full Text Available Attempts to prepare the mononuclear [(tpmNiIIL3]−1 [tpm = tris(1H-pyrazol-1-ylmethane and L = thiocyanate] anion yielded the methanol-solvated salt, [(tpm2NiII][(tpmNiII(NCS3]2·2CH3OH or [Ni(C10H10N62][Ni(NCS3(C10H10N6]2·2CH3OH. The asymmetric unit consists of half a centrosymmetric bis[tris(1H-pyrazol-1-ylmethane]nickel(II cation and an octahedral nickelate(II anion bound to one tpm and three L ligands, and a methanol solvent molecule. One of the L ligands is disordered over two positions with occupancy factors of 0.650 (3 and 0.350 (3. There are O—H...S interactions between the methanol and the disordered thiocyanate anion, and a weak C—H...O hydrogen bond between the cation and the methanol O atom.

  17. Polymerization of 1,3-butadiene catalyzed by pincer cobalt(II) complexes derived from 2-(1-arylimino)-6-(pyrazol-1-yl)pyridine ligands

    KAUST Repository

    Gong, Dirong; Jia, Weiguo; Chen, Tao; Huang, Kuo-Wei

    2013-01-01

    A new class of air stable and structurally well-defined cobalt complexes with unsymmetrical pincer type ligands ([2-(ArNCMe)-6-(Py)C5H 3N]CoCl2) (Ar = C6H5, Py = pyrazol-1-yl, 5a; Ar = 2,4,6-Me3C6H2, Py = pyrazol-1-yl, 5b; Ar = 2,6-iPr2C6H3, Py

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  19. Crystal Structure of N,N,N’,N’-tetra-[(3,5-dimethyl-1-pyrazolyl methyl]-para-phenylenediamine

    Directory of Open Access Journals (Sweden)

    Taibi Ben-Hadda

    2003-02-01

    Full Text Available The title compound, molecular formula C30H40N10, crystallizes and exhibits a cisoidal conformation around a central p-phenylenediamine ring suggesting that this bis-tripodal ligand is highly flexible and could be accommodated by many and original metal coordinations. All four five-membered pyrazole rings are identical. The molecule presents an inversion centre that coincides with the phenyl ring centre: pyrazole rings are two-by-two equivalent. The electrostatic spatial intramolecular repulsion between N4 and N5 is probably responsible for this general arrangement. These data emphasize the basic character of nitrogens N4 and N5.

  20. 4-{[(1-Phenyl-1H-pyrazol-3-yloxy]methyl}-1,3-dioxolan-2-one

    Directory of Open Access Journals (Sweden)

    Algirdas Šačkus

    2012-11-01

    Full Text Available The title compound was obtained by the reaction of tosylated glycerol carbonate with 1-phenyl-1H-pyrazol-3-ol in a good 71% yield. Detailed spectroscopic data (1H-NMR, 13C-NMR, 15N-NMR, IR, MS are presented.

  1. (2E-3-(3-Methoxy-1-phenyl-1H-pyrazol-4-yl-2-propenal

    Directory of Open Access Journals (Sweden)

    Algirdas Šačkus

    2009-12-01

    Full Text Available The palladium-catalyzed reaction of 4-bromo-3-methoxy-1-phenyl-1H-pyrazole with acrolein diethyl acetal gives the title compound in good yield. Detailed spectroscopic data (1H NMR, 13C NMR, 15N NMR, IR, MS are presented.

  2. A critical review of both the synthesis approach and the receptor profile of the 8-chloro-1-(2',4'-dichlorophenyl)-N-piperidin-1-yl-1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole-3-carboxamide and analogue derivatives.

    Science.gov (United States)

    Lazzari, Paolo; Distinto, Rita; Manca, Ilaria; Baillie, Gemma; Murineddu, Gabriele; Pira, Marilena; Falzoi, Matteo; Sani, Monica; Morales, Paula; Ross, Ruth; Zanda, Matteo; Jagerovic, Nadine; Pinna, Gérard Aimè

    2016-10-04

    8-Chloro-1-(2',4'-dichlorophenyl)-N-piperidin-1-yl-1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole-3-carboxamide 9a was discovered as potent and selective CB1 antagonist by part of our group few years ago. In particular it was reported to have an affinity towards the CB1 cannabinoid receptor (CB1R), expressed as Ki, of 0.00035 nM. Nevertheless significantly divergent data were reported for the same compound from other laboratories. To unequivocally define the receptor profile of 9a, we have critically reviewed both its synthesis approach and binding data. Here we report that, in contrast to our previously reported data, 9a showed a Ki value for CB1R in the order of nanomolar rather than of fentomolar range. The new determined receptor profile of 9a was also ascertained for analogue derivatives 9b-i, as well as for 12. Moreover, the structural features of the synthesized compounds necessary for CB1R were investigated. Amongst the novel series, effects on CB1R intrinsic activity was highlighted due to the substituents at the position 3 of the pyrazole ring of the 1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole scaffold. Although the cannabinoid receptor profile of 9a was reviewed in this work, the relevance of this compound in CB1R antagonist based drug discovery is confirmed. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  3. New octahedral ZnII and CdII complexes based on azo derivatives and azomethines of pyrazole-5-thione

    International Nuclear Information System (INIS)

    Uraev, A.I.; Vasil'chenko, I.S.; Borodkin, G.S.; Borodkina, I.G.; Vlasenko, V.G.; Burlov, A.S.; Divaeva, L.N.; Garnovskij, A.D.; Lysenko, K.A.; Antipin, M.Yu.

    2005-01-01

    New metal chelates of Zn II and Cd II (ML 2 ) based on (4Z)-3-methyl-1-phenyl-5-thioxo- 1,5-dihydro-4H-pyrazol-4-one quinolin-8-ylhydrazone (HL 1 ) and (4Z)-5-methyl-2-phenyl- 4-[(quinolin-8-ylimino)methyl]-2,4-dihydro-3H-pyrazole-3-thione (HL 2 ) were synthesized. The structures of the metal chelates were studied by EXAFS and NMR ( 1 H, 13 C, and 111 Cd) spectroscopy. The structure of the Cd(L 1 ) 2 complex was established by X-ray diffraction analysis. The complexes have pseudo octahedral structures with the N 4 S 2 ligand environment [ru

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

    Science.gov (United States)

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

    2011-10-09

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

  5. Synthesis, Characterization, Antimicrobial Screening and Free-Radical Scavenging Activity of Some Novel Substituted Pyrazoles

    Directory of Open Access Journals (Sweden)

    Nagwa Mohamed Mahrous Hamada

    2015-06-01

    Full Text Available The present work deals with the synthesis of acetoxysulfonamide pyrazole derivatives, substituted 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives starting from substituted vanillin chalcones. Acetoxysulfonamide pyrazole derivatives were prepared from the reaction of chalcones with p-sulfamylphenylhydrazine followed by treatment with acetic anhydride. At the same time 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives were prepared from the reaction of chalcones with either thiosemicarbazide or isonicotinic acid hydrazide, respectively. The synthesized compounds were structurally characterized on the basis of IR, 1H-NMR, 13C-NMR spectral data and microanalyses. All of the newly isolated compounds were tested for their antimicrobial activities. The antimicrobial screening using the agar well-diffusion method revealed that the chloro derivatives are the most active ones. Moreover, the antioxidant and anti-inflammatory activity of these chloro derivatives are also studied using the DPPH radical scavenging and NO radical scavenging methods, respectively.

  6. Synthesis and Anti-inflammatory Activity of Some Novel Pyrazole Derivatives of Gallic Acid

    Directory of Open Access Journals (Sweden)

    S. Arunkumar

    2009-01-01

    Full Text Available In the present study, a new series of [5-substituted-3-(phenylamino-1H-pyrazol-1yl] (3,4,5-trihydroxyphenyl-methanone (4a-j have been synthesized. 3, 4, 5-Trihydroxy benzohydrazide (1 was synthesized from propyl gallate and hydrazine hydrate in presence of ethanol. Chalcones (2a-j were synthesized from acetanilide and various aromatic aldehydes in presence of ethanol and sodium hydroxide solution. By refluxing the compound (1 and compounds (2a-j in presence of ethanol yielded [5-substituted-3-(phenylamino-4.5-dihydropyrazol-1yl] (3,4,5-trihydroxy phenyl-methanone (3a-j. The final compounds [5-substituted-3-(phenylamino-1H-pyrazol-1yl] (3,4,5-trihydroxyphenyl-methanone (4a-j were synthesized by treating compounds (3a-j with bromine water. The synthesized compounds have been characterized by IR, 1HNMR and Mass spectral data. The compounds were evaluated for in vivo anti-inflammatory activity by carrageenan induced paw edema test. In general all compounds were found to exhibit good anti-inflammatory activity.

  7. Microwave-assisted synthesis of N-pyrazole ureas and the p38alpha inhibitor BIRB 796 for study into accelerated cell ageing.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Dix, Matthew C; Widdowson, Caroline S; Kipling, David

    2006-11-21

    Microwave irradiation of substituted hydrazines and beta-ketoesters gives 5-aminopyrazoles in excellent yield, which can be transformed to the corresponding N-carbonyl derivatives by treatment with an isocyanate or chloroformate. Derivatization of 4-nitronaphth-1-ol using predominantly microwave heating methods and reaction with an N-pyrazole carbamate provides a rapid route to the N-pyrazole urea BIRB 796 in high purity, as a potent and selective inhibitor of p38alpha mitogen-activated protein kinase for the study of accelerated ageing in Werner syndrome cells.

  8. Ru-bis(pyridine)pyrazolate (bpp)-Based Water-Oxidation Catalysts Anchored on TiO2: The Importance of the Nature and Position of the Anchoring Group.

    Science.gov (United States)

    Francàs, Laia; Richmond, Craig; Garrido-Barros, Pablo; Planas, Nora; Roeser, Stephan; Benet-Buchholz, Jordi; Escriche, Lluís; Sala, Xavier; Llobet, Antoni

    2016-04-04

    Three distinct functionalisation strategies have been applied to the in,in-[{Ru(II)(trpy)}2(μ-bpp)(H2O)2](3+) (trpy=2,2':6',2''-terpyridine, bpp=bis(pyridine)pyrazolate) water-oxidation catalyst framework to form new derivatives that can adsorb onto titania substrates. Modifications included the addition of sulfonate, carboxylate, and phosphonate anchoring groups to the terpyridine and bis(pyridyl)pyrazolate ligands. The complexes were characterised in solution by using 1D NMR, 2D NMR, and UV/Vis spectroscopic analysis and electrochemical techniques. The complexes were then anchored on TiO2-coated fluorinated tin oxide (FTO) films, and the reactivity of these new materials as water-oxidation catalysts was tested electrochemically through controlled-potential electrolysis (CPE) with oxygen evolution detected by headspace analysis with a Clark electrode. The results obtained highlight the importance of the catalyst orientation with respect to the titania surface in regard to its capacity to catalytically oxidize water to dioxygen. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Experimental and theoretical study of pyrazole N-alkylation catalyzed by basic modified molecular sieves

    Czech Academy of Sciences Publication Activity Database

    Matos, I.; Pérez-Mayoral, E.; Soriano, E.; Zukal, Arnošt; Martín-Aranda, R. M.; López-Peinado, A. J.; Fonseca, I.; Čejka, Jiří

    2010-01-01

    Roč. 161, č. 3 (2010), s. 377-383 ISSN 1385-8947 R&D Projects: GA AV ČR 1QS400400560 Institutional research plan: CEZ:AV0Z40400503 Keywords : pyrazole alkylation * basic mesoporous materials * reaction mechanism Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.074, year: 2010

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  11. Microwave-assisted synthesis of new pyrazole derivatives bearing 1,2,3-triazole scaffold as potential antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Ashok Dongamanti

    2017-01-01

    Full Text Available A new series of (E-3-(3-(4-substituted phenyl-1-phenyl-1H-pyrazol- 4-yl-1-(2-hydroxy-4-((1-aryl-1H-1-2,3-triazol-4-ylmethoxyphenyl- prop-2-en-1-one derivatives was synthesized. The synthesis of the title compounds involved the 1,3-dipolar Cu(I-catalyzed alkyne–azide cycloaddition (CuAAC reaction of (E-3-(3-(4-substituted phenyl-1-phenyl-1H-pyrazol-4- -yl-1-(2-hydroxy-4-(prop-2-yn-1-yloxyphenylprop-2-en-1-ones with aromatic azides. The structures were confirmed by NMR, FT-IR, mass and elemental analysis. All the synthesized compounds (6a–j were evaluated for their antimicrobial activity. Compounds 6a, 6d and 6e demonstrated promising inhibitory effects on both bacterial and fungal strains.

  12. Synthesis of certain fused pyrazoles derived from 2-methyl-3-amino-6-iodo-4(3 H) quinazolinone as possible insecticidal and radiosensitizing agents

    International Nuclear Information System (INIS)

    Abdel-Hamide, S.G.; Ghorab, M.M.; Ali, G.M.

    1996-01-01

    The Verisimilar reaction on 3-amino-2-methyl-6-4-quinazolone (1) using P O Cl 3 /DMF afforded 3-formyl pyrazole derivative (2). The condensation products (3 a,b) were obtained via reaction of (2) with malononitrile or ethyl cyano acetate. Heating the condensation products (3 a,b) with acetyl derivatives in the presence of ammonium acetate yielded the corresponding cyano pyridines (9 a-e) and (10 a-e), respectively. Compounds (9 c) and (10 c) were obtained also from the interaction of the chalcone derivative (11) with malononitrile or ethyl cyano acetate. Condensation of (2) with semicarbazide hydrochloride, thio semicarbazide or aromatic amines gave the corresponding (12 a), (12 b) and (13 a-c), respectively. Compound (12 a) could be cyclized to (14) in acid medium. Interaction of compound (12 b) with chloro acetyl chloride gave (15). The Verisimilar reaction on Schiff bass (16) using P O Cl 3 /DMF gave the amino acrolein derivates (17), which was converted into 2-pyrazole derivative (18) and 2-isoxazolinyl derivative (19), respectively. The obtained compounds have been characterized on the basis of their IR, 'H-NMR and Mass spectral data and elemental analysis. Among the synthesized compounds only the formyl pyrazole derivative (2) and the azetidinylthioured derivative (15) showed a remarkable adulticidal activity. In addition the formyl pyrazole derivative (2) acted as a potent radiosensitizer. 2 figs., 3 tabs

  13. Effective electroluminescent materials for OLED applications based on lanthanide 1.3-diketonates bearing pyrazole moiety

    Energy Technology Data Exchange (ETDEWEB)

    Taydakov, Ilya V. [D. Mendeleyev University of Chemical Technology of Russia, Miusskaya pl. 9, 125047 Moscow (Russian Federation); P. N. Lebedev Institute of Physics of RAS, Leninskiy pr-t, 53, 119991 Moscow (Russian Federation); Akkuzina, Alina A.; Avetisov, Roman I.; Khomyakov, Andrew V.; Saifutyarov, Rasim R. [D. Mendeleyev University of Chemical Technology of Russia, Miusskaya pl. 9, 125047 Moscow (Russian Federation); Avetissov, Igor Ch., E-mail: igor_avetisov@mail.ru [D. Mendeleyev University of Chemical Technology of Russia, Miusskaya pl. 9, 125047 Moscow (Russian Federation)

    2016-09-15

    A series of new pyrazole substituted 1.3-diketones bearing fluorinated alkyl groups were prepared and systematically explored as a ligands for the preparation of luminescent complexes with Eu(III) ion. First triplet levels energy values (T1) of above mentioned ligands were determined by low temperature (77K) phosphorescent spectra measurements of Gd(III) complexes. It was found that 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)hexane-1,3-dione is a superior ligand for synthesis of highly luminescent Eu (III) complexes with 1.10-phenanthroline or similar Lewis bases as auxiliary ligands. The complexes are sufficiently thermal stable, transparent, volatile in high vacuum and soluble in common solvents which make possible to produce OLEDs by dry and wet technology. OLED structures fabricated on the base of the above Eu(III) complexes demonstrated the higher energy efficacy comparing to the standard Eu(TTA){sub 3}(Phen) phosphor.

  14. Optimization of a pyrazole hit from FBDD into a novel series of indazoles as ketohexokinase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuqing; Song, Fengbing; Kuo, Gee-Hong; Xiang, Amy; Gibbs, Alan C.; Abad, Marta C.; Sun, Weimei; Kuo, Lawrence C.; Sui, Zhihua (J); (J-PRD)

    2013-11-20

    A series of indazoles have been discovered as KHK inhibitors from a pyrazole hit identified through fragment-based drug discovery (FBDD). The optimization process guided by both X-ray crystallography and solution activity resulted in lead-like compounds with good pharmaceutical properties.

  15. Influence of ring growth rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

    2015-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

  16. 4-[(5-Hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-ylphenylmethyl]-5-methyl-2-phenyl-1H-pyrazol-3(2H-one ethanol hemisolvate

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2009-01-01

    Full Text Available The asymmetric unit of the title compound, C27H24N4O2·0.5C2H6O, comprises two crystallographically independent molecules (A and B with slightly different conformations, and one ethanol molecule of crystallization. Intramolecular C—H...O and O—H...O hydrogen bonds generate six- and eight-membered rings, producing S(6 and S(8 ring motifs, respectively. In molecule A, one of the benzene rings is disordered over two positions, with site-occupancy factors of 0.542 (11 and 0.458 (11. The dihedral angles between the central benzene ring and the two outer benzene rings are 73.88 (9 and 82.6 (2/88.9 (2° in molecule A, and 80.81 (8 and 79.38 (8° in molecule B. In the crystal structure, molecules form infinite one-dimensional chains in the (101 plane. The crystal structure is stabilized by intermolecular O—H...N, N—H...N, N—H...O and C—H...O hydrogen bonds, weak C—H...π and π–π [centroid–centroid = 3.5496 (1 Å] interactions.

  17. Structural optimization and biological evaluation of 1,5-disubstituted pyrazole-3-carboxamines as potent inhibitors of human 5-lipoxygenase

    Directory of Open Access Journals (Sweden)

    Yu Zhou

    2016-01-01

    Full Text Available Human 5-lipoxygenase (5-LOX is a well-validated drug target and its inhibitors are potential drugs for treating leukotriene-related disorders. Our previous work on structural optimization of the hit compound 2 from our in-house collection identified two lead compounds, 3a and 3b, exhibiting a potent inhibitory profile against 5-LOX with IC50 values less than 1 µmol/L in cell-based assays. Here, we further optimized these compounds to prepare a class of novel pyrazole derivatives by opening the fused-ring system. Several new compounds exhibited more potent inhibitory activity than the lead compounds against 5-LOX. In particular, compound 4e not only suppressed lipopolysaccharide-induced inflammation in brain inflammatory cells and protected neurons from oxidative toxicity, but also significantly decreased infarct damage in a mouse model of cerebral ischemia. Molecular docking analysis further confirmed the consistency of our theoretical results and experimental data. In conclusion, the excellent in vitro and in vivo inhibitory activities of these compounds against 5-LOX suggested that these novel chemical structures have a promising therapeutic potential to treat leukotriene-related disorders.

  18. Dichlorido{2-[(5-methyl-1H-pyrazol-3-yl-κN2methyl]-1H-1,3-benzimidazole-κN3}zinc

    Directory of Open Access Journals (Sweden)

    Karim Chkirate

    2017-01-01

    Full Text Available The asymmetric unit of the title complex, [ZnCl2(C12H12N4], contains two independent molecules having similar conformations. The coordination about the ZnII atom is distorted tetrahedral, with the geometrical constraints of the chelating ligand responsible for the observed distortion. Each of the independent molecules forms chains in the crystal through pairs of N—H...Cl hydrogen bonds, using the pyrazole and benzimidazole N—H groups as donors. The first molecule forms chains running parallel to the b axis, while the other molecule affords the same kind of one-dimensional supramolecular structure parallel to the a axis. The structure was refined as a two-component twin with BASF = 0.0437 (4.

  19. Synthesis, Antibacterial and Antifungal Activity of Some New Pyrazoline and Pyrazole Derivatives

    Directory of Open Access Journals (Sweden)

    Seham Y. Hassan

    2013-02-01

    Full Text Available A series of 2-pyrazolines 5–9 have been synthesized from α,β-unsaturated ketones 2–4. New 2-pyrazoline derivatives 13–15 bearing benzenesulfonamide moieties were then synthesized by condensing the appropriate chalcones 2–4 with 4-hydrazinyl benzenesulfonamide hydrochloride. Ethyl [1,2,4] triazolo[3,4-c][1,2,4]triazino[5,6-b]-5H-indole-5-ethanoate (26 and 1-(5H-[1,2,4]triazino[5,6-b] indol-3-yl-3-methyl-1H-pyrazol-5(4H-one (32 were synthesized from 3-hydrazinyl-5H-[1,2,4]triazino[5,6-b]indole (24. On the other hand ethyl[1,2,4]triazolo[3,4-c][1,2,4]triazino[5,6-b]-5,10-dihydroquinoxaline- 5-ethanoate (27 and 1-(5,10-dihydro-[1,2,4]triazino[5,6-b]quinoxalin-3-yl-3-methyl-1H-pyrazol-5(4H-one (33 were synthesized from 3-hydrazinyl-5,10-dihydro-[1,2,4]triazino[5,6-b]quinoxaline (25 by reaction with diethyl malonate or ethyl acetoacetate, respectively. Condensation of 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-2-carbaldehyde (1' with compound 24 or 25 afforded the corresponding Schiff's bases 36 and 37, respectively. Reaction of the Schiff's base 37 with benzoyl hydrazine or acetic anhydride afforded benzohydrazide derivative 39 and the cyclized compound 40, respectively. Furthermore, the pyrazole derivatives 42–44 were synthesized by cyclization of hydrazine derivative 25 with the prepared chalcones 2–4. All the newly synthesized compounds have been characterized on the basis of IR and 1H-NMR spectral data as well as physical data. Antimicrobial activity against the organisms E. coli ATCC8739 and P. aeruginosa ATCC 9027 as examples of Gram-negative bacteria, S. aureus ATCC 6583P as an example of Gram-positive bacteria and C. albicans ATCC 2091 as an example of a yeast-like fungus have been studied using the Nutrient Agar (NA and Sabouraud Dextrose Agar (SDA diffusion methods. The best performance was found for the compounds 16, 17, 19 and 20.

  20. Crystal structure of 3-methoxy-2-[5-(naphthalen-1-yl-4,5-dihydro-1H-pyrazol-3-yl]phenol

    Directory of Open Access Journals (Sweden)

    Dongsoo Koh

    2015-11-01

    Full Text Available In the title compound, C20H18N2O2, the central pyrazoline ring has an envelope conformation with the atom substituted by the naphthalene ring as the flap. It bridges a benzene ring and a naphthalene ring system which are almost normal to one another, making a dihedral angle of 82.03 (6 °. There is an intramolecular O—H...N hydrogen bond forming an S(6 ring motif. In the crystal, molecules are linked by pairs of N—H...π interactions, forming inversion dimers. There are also C—H...π interactions present and the dimers are linked via C—H...O hydrogen bonds, forming ribbons propagating along the a-axis direction.

  1. Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

    International Nuclear Information System (INIS)

    Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

    1986-01-01

    The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

  2. Synthesis, crystal structures, fluorescence and xanthine oxidase inhibitory activity of pyrazole-based 1,3,4-oxadiazole derivatives

    Science.gov (United States)

    Qi, De-Qiang; Yu, Chuan-Ming; You, Jin-Zong; Yang, Guang-Hui; Wang, Xue-Jie; Zhang, Yi-Ping

    2015-11-01

    A series of pyrazole-based 1,3,4-oxadiazole derivatives were rationally designed and synthesized in good yields by following a convenient route. All the newly synthesized molecules were fully characterized by IR, 1H NMR and elemental analysis. Eight compounds were structurally determined by single crystal X-ray diffraction analysis. The fluorescence properties of all the compounds were investigated in dimethyl sulfoxide media. In addition, these newly synthesized compounds were evaluated for in vitro inhibitory activity against commercial enzyme xanthine oxidase (XO) by measuring the formation of uric acid from xanthine. Among the compounds synthesized and tested, 3d and 3e were found to be moderate inhibitory activity against commercial XO with IC50 = 72.4 μM and 75.6 μM. The studies gave a new insight in further optimization of pyrazole-based 1,3,4-oxadiazole derivatives with excellent fluorescence properties and XO inhibitory activity.

  3. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Gheno, Giulia, E-mail: giulia.gheno@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Bortoluzzi, Marco; Ganzerla, Renzo [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera, Venezia (Italy)

    2014-01-15

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder.

  4. Secondary metabolites from the sponge Tedania anhelans: Isolation and characterization of two novel pyrazole acids and other metabolites

    Digital Repository Service at National Institute of Oceanography (India)

    Parameswaran, P.S.; Naik, C.G.; Hegde, V.R.

    Chemical investigation of the methanol extract of the sponge Tedania anhelans yielded the two unusual heteroaromatic acids, pyrazole-3(5)-carboxylic acid (2) and 4-methylpyrazole-3(5)-carboxylic acid (3), which are reported for the first time...

  5. Optimization of a pyrazole hit from FBDD into a novel series of indazoles as ketohexokinase inhibitors.

    Science.gov (United States)

    Zhang, Xuqing; Song, Fengbing; Kuo, Gee-Hong; Xiang, Amy; Gibbs, Alan C; Abad, Marta C; Sun, Weimei; Kuo, Lawrence C; Sui, Zhihua

    2011-08-15

    A series of indazoles have been discovered as KHK inhibitors from a pyrazole hit identified through fragment-based drug discovery (FBDD). The optimization process guided by both X-ray crystallography and solution activity resulted in lead-like compounds with good pharmaceutical properties. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Ligand-Promoted C(sp(3) )-H Olefination en Route to Multi-functionalized Pyrazoles.

    Science.gov (United States)

    Yang, Weibo; Ye, Shengqing; Schmidt, Yvonne; Stamos, Dean; Yu, Jin-Quan

    2016-05-17

    A Pd-catalyzed/N-heterocycle-directed C(sp(3) )-H olefination has been developed. The monoprotected amino acid ligand (MPAA) is found to significantly promote Pd-catalyzed C(sp(3) )-H olefination for the first time. Cu(OAc)2 instead of Ag(+) salts are used as the terminal oxidant. This reaction provides a useful method for the synthesis of alkylated pyrazoles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 4-[(3-Hydroxyanilino(phenylmethylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H-one

    Directory of Open Access Journals (Sweden)

    Keraghel Saida

    2012-06-01

    Full Text Available In the title compound, C23H19N3O2, the dihedral angles formed by the pyrazolone ring with the three benzene rings are 30.91 (6, 60.96 (4 and 57.01 (4°. The ligand is in the enamine–keto form and its structure is stabilized by an intramolecular N—H...O hydrogen bond. In the crystal, O—H...N hydrogen bonds link molecules into chains parallel to [01-1].

  8. Crystal structure of 3,5-dimethoxy-2-[5-(naphthalen-1-yl-4,5-dihydro-1H-pyrazol-3-yl]phenol

    Directory of Open Access Journals (Sweden)

    Dongsoo Koh

    2015-10-01

    Full Text Available In the title compound, C21H20N2O3, the planes of the benzene ring and the naphthalene ring system are inclined to one another by 70.95°, and by 4.99 (6 and 75.93 (5°, respectively, to the mean plane of the pyrazoline ring. The latter has an envelope conformation with the methine (CH C atom as the flap. There is an intramolecular O—H...N hydrogen bond that forms an S(6 ring motif. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming chains along [100]. The chains are linked via C—H...N hydrogen bonds, forming sheets parallel to the ab plane. The sheets are linked by a series of N—H...π and C—H...π interactions forming a three-dimensional structure.

  9. A study of the vaporization enthalpies of some 1-substituted imidazoles and pyrazoles by correlation-gas chromatography.

    Science.gov (United States)

    Lipkind, Dmitry; Plienrasri, Chatchawat; Chickos, James S

    2010-12-23

    The vaporization enthalpies of 1-methyl-, 1-ethyl-, 1-phenyl-, and 1-benzylimidazole, 1-methyl- and 1-phenylpyrazole, and trans-azobenzene are evaluated by correlation-gas chromatography (C-GC) using a variety of azines and diazines as standards. The vaporization enthalpies obtained by C-GC when compared to literature values are approximately 14 kJ·mol(-1) smaller for the imidazoles and 6 kJ·mol(-1) smaller for the pyrazoles. The literature vaporization enthalpies of 1-methylpyrrole and 1-methylindole, two closely related compounds with one less nitrogen, are reproduced by C-GC. These results suggest that the magnitude of the intermolecular interactions present in 1-substituted imidazoles and pyrazoles are significantly larger than the those present in the reference compounds and greater than or equal in magnitude to the enhanced intermolecular interactions observed previously in aromatic 1,2-diazines. The vaporization enthalpy and vapor pressure of a trans-1,2-diazine, trans-azobenzene, measured by C-GC using similar standards reproduced the literature values within experimental error.

  10. Synthesis of 3-(4, 5-dihydro-1-phenyl-5-substituted phenyl-1H-pyrazol-3-yl-2H-chromen-2-one derivatives and evaluation of their anticancer activity

    Directory of Open Access Journals (Sweden)

    Nitin Kumar

    2017-05-01

    Full Text Available A novel series of 3-(4, 5-dihydro-1-phenyl-5-substituted phenyl-1H-pyrazol-3-yl-2H-chromen-2-one derivatives were synthesized. In the first step salicylaldehyde was reacted with ethylacetoacetate at room temperature by stirring which gives compound (I. Compound (I when refluxed with substituted benzaldehyde and diethylamine in the presence of n-butanol for 4–5 h gives substituted derivatives (IIa–d. Compounds synthesized in step 2 when refluxed with phenyl hydrazine in the presence of pyridine for 6–7 h gives the title compounds (IIIa–d. All the synthesized compounds were sent to NCI for anticancer activity. Synthesized compounds were tested for anticancer activity against 60 different cell lines. From the data thus obtained it was observed that simple coumarin ring derivatives were more effective in inhibiting the growth of cancerous cell lines, than coumarin-pyrazoline derivatives. Among all the synthesized compounds, irrespective of compounds having simple coumarin ring and coumarin-pyrazoline combination, compounds IIa–c, IIIb and IIId were potent anticancer agents. Compounds were active for the single dose therapeutic program at the dose of 1.00E-5 molar concentration. The main anti cancer activity is assumed to be due to the presence of the lactone structure in coumarin moiety.

  11. Molecular and polymeric uranyl and thorium hybrid materials featuring methyl substituted pyrazole dicarboxylates and heterocyclic 1,3-diketones

    Science.gov (United States)

    Carter, Korey P.; Kerr, Andrew T.; Taydakov, Ilya V.; Cahill, Christopher L.

    2018-02-01

    A series of seven novel f-element bearing hybrid materials have been prepared from either methyl substituted 3,4 and 4,5-pyrazoledicarboxylic acids, or heterocyclic 1,3- diketonate ligands using hydrothermal conditions. Compounds 1, [UO2(C6H4N2O4)2(H2O)], and 3, [Th(C6H4N2O4)4(H2O)5]·H2O feature 1-Methyl-1H-pyrazole-3,4-dicarboxylate ligands (SVI-COOH 3,4), whereas 2, [UO2(C6H4N2O4)2(H2O)], and 4, [Th(C6H5N2O4)(OH)(H2O)6]2·2(C6H5N2O4)·3H2O feature 1-Methyl-1H-pyrazole-4,5-dicarboxylate moieties (SVI-COOH 4,5). Compounds 5, [UO2(C13H15N4O2)2(H2O)]·2H2O and 6, [UO2(C11H11N4O2)2(H2O)]·4.5H2O feature 1,3-bis(4-N1-methyl-pyrazolyl)propane-1,3-dione and 1,3-bis(4-N1,3-dimethyl-pyrazolyl)propane-1,3-dione respectively, whereas the heterometallic 7, [UO2(C11H11N4O2)2(CuCl2)(H2O)]·2H2O is formed by using 6 as a metalloligand starting material. Single crystal X-ray diffraction indicates that all coordination to either [UO2]2+ or Th(IV) metal centers is through O-donation as anticipated. Room temperature, solid-state luminescence studies indicate characteristic uranyl emissive behavior for 1 and 2, whereas those for 5 and 6 are weak and poorly resolved.

  12. Synthesis of fatty trichloromethyl-β-diketones and new 1H-Pyrazoles as unusual FAMEs and FAEEs

    International Nuclear Information System (INIS)

    Flores, Alex F.C.; Souto, Alynne A.; Malavolta, Juliana L.; Flores, Darlene C.; Blanco, Rogerio F.

    2013-01-01

    The efficient synthesis of new fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones [Cl 3 CC(O)C(R 2 )=C(R 1 )OMe, where R 1 = n-hexyl, heptyl, nonyl, undecyl, tridecyl and R 2 = H] and 1,1,1-trichloro-2,4-alkanediones [Cl 3 CC(O)CHR 2 C(O)R 1 , where R 1 = n-pentyl and R 2 = Me, R 1 = Et and R 2 = n-butyl, R 1 = n-butyl and R 2 = n-propyl] in good yields (85-95%) from acetal acylation with trichloroacetyl chloride is reported. The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1,1,1-trichloro-2,4-alkanediones were reacted with hydrazine hydrochloride, leading to respective 1 H-pyrazole-5-carboxylates, unusual class of fatty acid methyl (FAMEs) and ethyl (FAEEs) esters. Their structures were confirmed by elemental analysis and 1 H and 13 C nuclear magnetic resonance (NMR). The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1 H-pyrazole derivatives are new oleochemicals with potentially interesting and differential properties. (author)

  13. Combinatorial Libraries on Rigid Scaffolds: Solid Phase Synthesis of Variably Substituted Pyrazoles and Isoxazoles

    Directory of Open Access Journals (Sweden)

    Eduard R. Felder

    1997-01-01

    Full Text Available The synthesis of combinatorial compound libraries has become a powerful lead finding tool in modern drug discovery. The ability to synthesize rapidly, in high yield, new chemical entities with low molecular weight on a solid support has a recognized strategic relevance (“small molecule libraries”. We designed and validated a novel solid phase synthesis scheme, suitable to generate diversity on small heterocycles of the pyrazole and isoxazole type. Appropriate conditions were worked out for each reaction, and a variety of more or less reactive agents (building blocks was utilized for discrete conversions, in order to exploit the system’s breadth of applicability. Four sequential reaction steps were validated, including the loading of the support with an acetyl bearing moiety, a Claisen condensation, an a-alkylation and a cyclization of a b-diketone with monosubstituted hydrazines. In a second stage, the reaction sequence was applied in a split and mix approach, in order to prepare a combinatorial library built-up from 4 acetyl carboxylic acids (R1, 35 carboxylic esters (R2 and 41 hydrazines (R4 (and 1 hydroxylamine to yield a total of 11,760 compounds divided into 41 pyrazole sublibraries with 140 pairs of regioisomers and 1 isoxazole sublibrary of equal size.

  14. trans-Bis(perchlorato-κOtetrakis(1H-pyrazole-κN2copper(II

    Directory of Open Access Journals (Sweden)

    Viktor Zapol'skii

    2008-10-01

    Full Text Available The title compound, [Cu(ClO42(C3H4N24], was obtained unexpectedly by the reaction of copper(II perchlorate hexahydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octahedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1 Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11 Å].

  15. Synthesis of novel N1-substituted bicyclic pyrazole amino acids and evaluation of their interaction with glutamate receptors

    DEFF Research Database (Denmark)

    Conti, Paola; Grazioso, Giovanni; di Ventimiglia, Samuele Joppolo

    2005-01-01

    N1-substituted bicyclic pyrazole amino acids (S)-9a-9c and (R)-9a-9c, which are conformationally constrained analogues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested for activity at ionotropic and metabotropic glutamate receptors...

  16. Synthesis and antileishmanial activity of new 1-Aryl-1H-Pyrazole-4- carboximidamides derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Mauricio S. dos; Gomes, Adriana O.; Bernardino, Alice M.R.; Souza, Marcos C. de, E-mail: alicerolim@globo.co [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-Graduacao em Quimica Organica; Khan, Misbahul A. [The Islamia University of Bahawalpur (Pakistan). Chemistry Dept.; Brito, Monique A. de [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Fac. de Farmacia. Lab. de Quimica Medicinal Computacional; Castro, Helena C.; Abreu, Paula A. [Universidade Federal Fluminense (LABioMol/GCM/UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Antibioticos, Bioquimica e Modelagem Molecular; Rodrigues, Carlos R. [Universidade Federal do Rio de Janeiro (ModMol/UFRJ), RJ (Brazil). Fac. de Farmacia. Lab. de Modelagem Molecular e QSAR; Leo, Rosa M.M. de; Leon, Leonor L.; Canto-Cavalheiro, Marilene M. [Fundacao Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto Oswaldo Cruz. Lab. de Bioquimica de Tripanosomatideos

    2011-07-01

    Chemotherapy for leishmaniasis, diseases caused by protozoa of the genus Leishmania, remains inefficient in several treatments. So there is a need to search for new drugs. In this work, we have synthesized 1-aryl-1H-pyrazole-4-carboximidamides derivatives and evaluated antileishmanial activities in vitro, as well as cytotoxic effects. Structure-activity relationship (SAR) studies were carried out with all the compounds of the series. Compound 2 showed an activity profile that can be improved through medicinal chemistry strategies. (author)

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

    Science.gov (United States)

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

    2002-12-24

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

  18. From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

    Science.gov (United States)

    Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

    2018-03-01

    We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

  19. Ultrasonics Promoted Synthesis of 5-(Pyrazol-4-yl-4,5-Dihydropyrazoles Derivatives

    Directory of Open Access Journals (Sweden)

    Manuel Nogueras

    2013-04-01

    Full Text Available A series of new 1,3-diaryl-5-(1-phenyl-3-methyl-5-chloropyrazol-4-yl-4,5-dihydropyrazole derivatives have been synthesized under sonication conditions in ethanol or methanol/glacial acetic acid mixture (5/1 ratio with two equivalents of hydrazines and seven kinds of chalcone-like heteroanalogues obtained from 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde. The structures were established on the basis of NMR, IR, MS and element analysis. This method provides several advantages over current reaction methodologies, including a simple work-up procedure, shorter reaction times (2–20 min and good yields (65%–80%.

  20. Azomethines, isoxazole, N-substituted pyrazoles and pyrimidine containing curcumin derivatives: Urease inhibition and molecular modeling studies.

    Science.gov (United States)

    Ahmed, Mahmood; Qadir, Muhammad Abdul; Hameed, Abdul; Arshad, Muhammad Nadeem; Asiri, Abdullah M; Muddassar, Muhammad

    2017-08-19

    Curcumin has shown large number of pharmacological properties against different phenotypes of various disease models. Different synthetic routes have been employed to develop its various derivatives for diverse biological functions. In this study, curcumin derived azomethine, isoxazole, pyrimidines and N-substituted pyrazoles were synthesized to investigate their urease enzyme inhibition. The structures of newly synthesized compounds were described by IR, MS, 1 H NMR and 13 C NMR spectral data. Urease enzyme inhibition was evaluated through in vitro assays in which compound 8b was found to be the most potent (IC 50  = 2.44 ± 0.07 μM) among the tested compounds. The compounds with diazine ring system except the 4d showed better urease inhibition (IC 50  = 11.43 ± 0.21-19.63 ± 0.28 μM) than the standard urease inhibitor thiourea (IC 50  = 22.61 ± 0.23 μM). Similarly enzyme kinetics data revealed that compounds 3c-3e and 8b were competitive inhibitors with Ki values of 20.0, 19.87, 20.23 and 19.11 μM respectively while the compounds 4b, 4c and 4e were mixed type of inhibitors with Ki values 6.72, 19.69 and 6.72 μM respectively. Molecular docking studies were also performed to identify the plausible binding modes of the most active compounds. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Synthesis of fatty trichloromethyl-{beta}-diketones and new 1H-Pyrazoles as unusual FAMEs and FAEEs

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Alex F.C.; Souto, Alynne A.; Malavolta, Juliana L.; Flores, Darlene C., E-mail: alex.fcf@ufsm.br [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Departamento de Quimica; Blanco, Rogerio F. [Uniao de Ensino do Sudoeste do Parana (UNISEP), Dois Vizinhos, PR (Brazil). Faculdade de Farmacia

    2013-12-01

    The efficient synthesis of new fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones [Cl{sub 3}CC(O)C(R{sup 2})=C(R{sup 1})OMe, where R{sup 1} = n-hexyl, heptyl, nonyl, undecyl, tridecyl and R{sup 2} = H] and 1,1,1-trichloro-2,4-alkanediones [Cl{sub 3}CC(O)CHR{sup 2}C(O)R{sup 1}, where R{sup 1} = n-pentyl and R{sup 2} = Me, R{sup 1} = Et and R{sup 2} = n-butyl, R{sup 1} = n-butyl and R{sup 2} = n-propyl] in good yields (85-95%) from acetal acylation with trichloroacetyl chloride is reported. The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1,1,1-trichloro-2,4-alkanediones were reacted with hydrazine hydrochloride, leading to respective {sup 1}H-pyrazole-5-carboxylates, unusual class of fatty acid methyl (FAMEs) and ethyl (FAEEs) esters. Their structures were confirmed by elemental analysis and {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR). The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and {sup 1}H-pyrazole derivatives are new oleochemicals with potentially interesting and differential properties. (author)

  2. Halogen-bonded network of trinuclear copper(II 4-iodopyrazolate complexes formed by mutual breakdown of chloroform and nanojars

    Directory of Open Access Journals (Sweden)

    Stuart A. Surmann

    2016-11-01

    Full Text Available Crystals of bis(tetrabutylammonium di-μ3-chlorido-tris(μ2-4-iodopyrazolato-κ2N:N′tris[chloridocuprate(II] 1,4-dioxane hemisolvate, (C16H36N2[Cu3(C3H2IN23Cl5]·0.5C4H8O or (Bu4N2[CuII3(μ3-Cl2(μ-4-I-pz3Cl3]·0.5C4H8O, were obtained by evaporating a solution of (Bu4N2[{CuII(μ-OH(μ-4-I-pz}nCO3] (n = 27–31 nanojars in chloroform/1,4-dioxane. The decomposition of chloroform in the presence of oxygen and moisture provides HCl, which leads to the breakdown of nanojars to the title trinuclear copper(II pyrazolate complex, and possibly CuII ions and free 4-iodopyrazole. CuII ions, in turn, act as catalyst for the accelerated decomposition of chloroform, ultimately leading to the complete breakdown of nanojars. The crystal structure presented here provides the first structural description of a trinuclear copper(II pyrazolate complex with iodine-substituted pyrazoles. In contrast to related trinuclear complexes based on differently substituted 4-R-pyrazoles (R = H, Cl, Br, Me, the [Cu3(μ-4-I-pz3Cl3] core in the title complex is nearly planar. This difference is likely a result of the presence of the iodine substituent, which provides a unique, novel feature in copper pyrazolate chemistry. Thus, the iodine atoms form halogen bonds with the terminal chlorido ligands of the surrounding complexes [mean length of I...Cl contacts = 3.48 (1 Å], leading to an extended two-dimensional, halogen-bonded network along (-110. The cavities within this framework are filled by centrosymmetric 1,4-dioxane solvent molecules, which create further bridges via C—H...Cl hydrogen bonds with terminal chlorido ligands of the trinuclear complex not involved in halogen bonding.

  3. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1982-01-01

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  4. Synthesis and Herbicidal Activity of 5-Heterocycloxy-3-substituted-1-(3-trifluoromethyl)phenyl-1H-pyrazole

    Institute of Scientific and Technical Information of China (English)

    XU Han; HU Xu-hong; ZOU Xiao-mao; ZHU You-quan; LIU Bin; HU Fang-zhong; YANG Hua-zheng

    2012-01-01

    The authors synthesized a series of novel 5-heterocycloxy-3-substituted-1-(3-trifluoromethyl)phenyl-1H- pyrazole derivatives.Herbicidal activities of the two intermediate compounds and thirteen target compounds were evaluated via Brassica napus and Echinochloa crusgalli(L.) Beauv tests.Bioassay results show that some of the compounds exhibit better inhibiting activities against Brassica napus and some of the compounds exhibit bleaching activities against Echinochloa crusgalli(L.) Beauv at 100 μg/mL.

  5. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

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

  6. Formalized Linear Algebra over Elementary Divisor Rings in Coq

    OpenAIRE

    Cano , Guillaume; Cohen , Cyril; Dénès , Maxime; Mörtberg , Anders; Siles , Vincent

    2016-01-01

    International audience; This paper presents a Coq formalization of linear algebra over elementary divisor rings, that is, rings where every matrix is equivalent to a matrix in Smith normal form. The main results are the formalization that these rings support essential operations of linear algebra, the classification theorem of finitely pre-sented modules over such rings and the uniqueness of the Smith normal form up to multiplication by units. We present formally verified algorithms comput-in...

  7. Precision ring rolling technique and application in high-performance bearing manufacturing

    Directory of Open Access Journals (Sweden)

    Hua Lin

    2015-01-01

    Full Text Available High-performance bearing has significant application in many important industry fields, like automobile, precision machine tool, wind power, etc. Precision ring rolling is an advanced rotary forming technique to manufacture high-performance seamless bearing ring thus can improve the working life of bearing. In this paper, three kinds of precision ring rolling techniques adapt to different dimensional ranges of bearings are introduced, which are cold ring rolling for small-scale bearing, hot radial ring rolling for medium-scale bearing and hot radial-axial ring rolling for large-scale bearing. The forming principles, technological features and forming equipments for three kinds of precision ring rolling techniques are summarized, the technological development and industrial application in China are introduced, and the main technological development trend is described.

  8. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

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

  9. Evidence for Quantisation in Planetary Ring Systems

    OpenAIRE

    WAYTE, RICHARD

    2017-01-01

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

  10. Investigation of piston ring – cylinder liner dry wear using a block-on-ring test rig

    DEFF Research Database (Denmark)

    Bihlet, Uffe; Klit, Peder; Felter, Christian L.

    Characterization of the wear of piston rings and cylinder liner is an important aspect of large two stroke diesel engine design. Two major wear mechanisms exist; corrosive wear and mechanical wear. This paper deals with the most aggressive form of the latter, which is known as scuffing. Different...... that ceramic coating on the piston ring decreases the dry wear rate of both piston ring and liner, while the coefficient of friction is increased....

  11. Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

    Science.gov (United States)

    Allegri, G.; Giorleo, L.; Ceretti, E.

    2018-05-01

    Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

  12. Generation of Polar Semi-Saturated Bicyclic Pyrazoles for Fragment-Based Drug Discovery Campaigns.

    Science.gov (United States)

    Luise, Nicola; Wyatt, Paul

    2018-05-07

    Synthesising polar semi-saturated bicyclic heterocycles can lead to better starting points for fragment-based drug discovery (FBDD) programs. This communication highlights the application of diverse chemistry to construct bicyclic systems from a common intermediate, where pyrazole, a privileged heteroaromatic able to bind effectively to biological targets, is fused to diverse saturated counterparts. The generated fragments can be further developed either after confirmation of their binding pose or early in the process, as their synthetic intermediates. Essential quality control (QC) for selection of small molecules to add to a fragment library is discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Experimental Study of Shock Generated Compressible Vortex Ring

    Science.gov (United States)

    Das, Debopam; Arakeri, Jaywant H.; Krothapalli, Anjaneyulu

    2000-11-01

    Formation of a compressible vortex ring and generation of sound associated with it is studied experimentally. Impulse of a shock wave is used to generate a vortex ring from the open end of a shock-tube. Vortex ring formation process has been studied in details using particle image Velocimetry (PIV). As the shock wave exits the tube it diffracts and expands. A circular vortex sheet forms at the edge and rolls up into a vortex ring. Far field microphone measurement shows that the acoustic pressure consists of a spike due to shock wave followed by a low frequency pressure wave of decaying nature, superimposed with high frequency pressure wave. Acoustic waves consist of waves due to expansion, waves formed in the tube during diaphragm breakage and waves associated with the vortex ring and shear-layer vortices. Unsteady evolution of the vortex ring and shear-layer vortices in the jet behind the ring is studied by measuring the velocity field using PIV. Corresponding vorticity field, circulation around the vortex core and growth rate of the vortex core is calculated from the measured velocity field. The velocity field in a compressible vortex ring differs from that of an incompressible ring due to the contribution from both shock and vortex ring.

  14. Minimal Gromov-Witten rings

    International Nuclear Information System (INIS)

    Przyjalkowski, V V

    2008-01-01

    We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

  15. Theoretical study on electronic structures and optical properties of blue phosphorescent Iridium(III) complexes with C{sup ∧}N and N{sup ∧}N ligands

    Energy Technology Data Exchange (ETDEWEB)

    Shang, Xiaohong [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); College of Chemistry and Life Science, Changchun University of Technology, Changchun 130024 (China); Liu, Yuqi; Qu, Xiaochun [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Wu, Zhijian, E-mail: zjwu@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2013-11-15

    We report a quantum-chemical study on the electronic structures and optical properties of two series of heteroleptic iridium(III) complexes [(dfb-pz){sub 2}Ir(N{sup ∧}N+sub)], [dfb-pz=2,4-difluorobenzyl-N-pyrazole, sub indicates substituent group, N{sup ∧}N+sub=tphppz=4-tert-butyl-2-(5-phenyl-[1,2,4]triazol-3-yl)-pyridine (1a), tmppz=4-tert-butyl-2-(5-methyl-[1,2,4]triazol-3-yl)-pyridine (1b), fphppz=4-fluoro-phenyl-5-(2-pyridyl)pyrazole (1c), and fmphppz=4-trifluoromehtyl-phenyl-5-(2-pyridyl)pyrazole (1d)]; with [(C{sup ∧}N+sub){sub 2}Ir(fppz)], [C{sup ∧}N=b-pz=benzyl-N-pyrazole, fppz=3-trifluoromethyl-5-(2-pyridyl)pyrazole, C{sup ∧}N+sub=dfb-pz=2,4-difluorobenzyl-N-pyrazole (2a), tfmfb-pz=2-trifluoromethyl-5-fluorobenzyl-N-pyrazole (2b), phb-pz=3-phenyl-benzyl-N-pyrazole (2c), and dfphb-pz=3-phenyl-2,4-difluorobenzyl-N-pyrazole (2d)]. The calculated results shed light on the reasons of the remarkably manipulated excited-state and electroluminescent properties through substitution effect. The phenyl ring on main ligands can enhance the π-conjugation of the main ligands moiety and increase the metal-ligand bond strength for 2c and 2d, then enhancing the transition strength. From 1c, 1d, 2c, and 2d, it can also be seen that substituents on the terminal phenyl ring have a slight effect on the excited energy because the distance between the substituents and the ancillary (or main) ligand is interrupted by the phenyl moiety. The calculated absorption and luminescence properties of the four complexes 1a, 1b, 2a, and 2b are compared with the available experimental data and a good agreement is obtained. Furthermore, the assumed complex 1c, 2c, and 2d possess better charge transfer abilities and more balanced charge transfer rates. The designed complexes 2c and 2d are potential candidates for blue phosphorescent materials. -- Highlights: • Two series of electroluminescent iridium(III) complexes have been studied. • The charge transfer properties are affected

  16. Toxicological evaluation of a novel cooling compound: 2-(4-methylphenoxy-N-(1H-pyrazol-3-yl-N-(2-thienylmethylacetamide

    Directory of Open Access Journals (Sweden)

    Donald S. Karanewsky

    2015-01-01

    Full Text Available A toxicological evaluation of a novel cooling agent, 2-(4-methylphenoxy-N-(1H-pyrazol-3-yl-N-(2-thienylmethyl acetamide (S2227; CAS 1374760-95-8, was completed for the purpose of assessing its safety for use in food and beverage applications. S2227 undergoes rapid oxidative metabolism in vitro, and in rat and dog pharmacokinetic studies is rapidly converted to its component carboxylic acid and secondary amine. S2227 was not found to be mutagenic or clastogenic in vitro, and did not induce micronuclei in polychromatic erythrocytes in vivo. The secondary amine hydrolysis product, N-(2-thienylmethyl-1H-pyrazol-3-amine (M179, was also evaluated for genotoxicity. In subchronic oral toxicity studies in rats, the no-observed-adverse-effect-level (NOAEL for S2227 was 100 mg/kg/day (highest dose tested when administered by oral gavage for 90 consecutive days. Furthermore, S2227 demonstrated a lack of maternal toxicity, as well as adverse effects on fetal morphology at the highest dose tested, providing a NOAEL of 1000 mg/kg/day for both maternal toxicity and embryo/fetal development when administered orally during gestation to pregnant rats.

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

    Directory of Open Access Journals (Sweden)

    S. A. Chertov

    2014-04-01

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

  18. Accidental ingestion of BiTine ring and a note on inefficient ring separation forceps

    Directory of Open Access Journals (Sweden)

    Baghele ON

    2011-05-01

    Full Text Available Om Nemichand Baghele1, Mangala Om Baghele21Department of Periodontology, SMBT Dental College and Hospital, Sangamner, Ahmednagar, Maharashtra, India; 2Private General Dental Practice, Mumbai, IndiaBackground: Accidental ingestion of medium-to-large instruments is relatively uncommon during dental treatment but can be potentially dangerous. A case of BiTine ring ingestion is presented with a note on inefficient ring separation forceps.Case description: A 28-year-old male patient accidentally ingested the BiTine ring (2 cm diameter, 0.5 cm outward projections while it was being applied to a distoproximal cavity in tooth # 19. The ring placement forceps were excessively flexible; bending of the beaks towards the ring combined with a poor no-slippage mechanism led to sudden disengagement of the ring and accelerated movement towards the pharynx. We followed the patient with bulk forming agents and radiographs. Fortunately the ring passed out without any complications.Clinical implications: Checking equipment and methods is as important as taking precautions against any preventable medical emergency. It is the responsibility of the clinician to check, verify and then use any instrument/equipment.Keywords: foreign bodies/radiography, foreign bodies/complications, equipment failure, dental instrument, accidental ingestion

  19. Application of 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea as sensing material for construction of Tm3+-PVC membrane sensor

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Feizyzadeh, Babak; Faridbod, Farnoush; Ganjali, Mohammad Reza

    2011-01-01

    A thulium(III) membrane sensor was made using 2% sodium tetraphenyl borate (NaTPB), 65% dibutylphthalate (DBP), 30% poly(vinyl chloride) (PVC) and 3% 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea (ET) as an ionophore. Conductometric study shows selectivity of the Et toward Tm 3+ ions. Nernstian response of 19.6 ± 0.4 mV per decade of thulium concentration was observed, and the electrode worked well in concentration range of 1.0 x 10 -6 to 1.0 x 10 -2 mol L -1 with a lower detection limit (LDL) of 7.2 x 10 -7 mol L -1 , in a pH range of 4.3-10.4. The selectivity of the sensor over alkaline, alkaline earth, transition and heavy metal ions was also found to be in a satisfactory range. To check the analytical applicability of the proposed Tm 3+ sensor, it was successfully used as an indicator electrode in analysis of thulium in certified reference materials. - Research highlights: → This work reports development of polymeric membrane sensor for Tm3+ determination in certified reference materials. → The novelty of this work is based on the high affinity of the ionophore toward the Tm3+ ions which causes the high selectivity of the sensor. → The newly developed sensor is superior to the formerly reported Tm3+ sensors in terms of selectivity and detection limit.

  20. Device for monitoring electron-ion ring parameters

    International Nuclear Information System (INIS)

    Tyutyunnikov, S.I.; Shalyapin, V.N.

    1982-01-01

    The invention is classified as the method of collective ion acceleration. The device for electron-ion ring parameters monitoring is described. The invention is aimed at increasing functional possibilities of the device at the expense of the enchance in the number of the ring controlled parameters. The device comprises three similar plane mirrors installed over accelerating tube circumference and a mirror manufactured in the form of prism and located in the tube centre, as well as the system of synchrotron radiation recording and processing. Two plane mirrors are installed at an angle of 45 deg to the vertical axis. The angle of the third plane mirror 3 α and that of prismatic mirror 2 α to the vertical axis depend on geometric parameters of the ring and accelerating tube and they are determined by the expression α=arc sin R K /2(R T -L), where R K - ring radius, R T - accelerating tube radius, L - the height of segment, formed by the mirror and inner surface of the accelerating tube. The device suggested permits to determine longitudinal dimensions of the ring, its velocity and the number of electrons and ions in the ring

  1. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

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

    2018-03-01

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

  2. Experimental and theoretical studies of a pyrazole-thiazolidin-2,4-di-one hybrid

    Science.gov (United States)

    Mushtaque, Md.; Avecilla, Fernando; Haque, Ashanul; Perwez, Ahmad; Khan, Md. Shahzad; Rizvi, M. Moshahid Alam

    2017-08-01

    The present work describes synthesis, characterization and biological evaluations of a hybrid compound 10 composed of two intriguing scaffolds pyrazole and thiazolidin-2,4-di-one. The title compound was obtained via multi-step reaction and characterized by a number of techniques (viz. IR, UV-Visible, 1H-NMR, 13C-NMR and MS) including X-ray crystallography. The structural and photophysical data of compound 10 were well supported by theoretical calculations performed at density functional (DFT) level. In-vitro anticancer studies on different human cancer cell lines indicated moderate to low activity of the compounds. The molecular target of the compound was predicted through in-silico studies. Finding of the studies are presented herein.

  3. Phototransformation of the insecticide fipronil: identification of novel photoproducts and evidence for an alternative pathway of photodegradation.

    Science.gov (United States)

    Raveton, Muriel; Aajoud, Asmae; Willison, John C; Aouadi, Heddia; Tissut, Michel; Ravanel, Patrick

    2006-07-01

    Fipronil is a recently discovered insecticide of the phenylpyrazole series. It has a highly selective biochemical mode of action, which has led to its use in a large number of important agronomical, household, and veterinary applications. Previous studies have shown that, during exposure to light, fipronil is converted into a desulfurated derivative (desulfinyl-fipronil), which has slightly reduced insecticidal activity. In this study, the photodegradation of fipronil was studied in solution at low light intensities (sunlight or UV lamp). In addition to desulfinyl-fipronil, a large number of minor photoproducts were observed, including diversely substituted phenylpyrazole derivatives and aniline derivatives that had lost the pyrazole ring. Desulfinylfipronil itself was shown to be relatively stable under both UV light and sunlight, with only limited changes occurring in the substitution of the aromatic ring. Since this compound accumulated to levels corresponding to only 30-55% of the amount of fipronil degraded, it was concluded that one or more alternative pathways of photodegradation must be operating. On the basis of the structurally identified photoproducts, it is proposed that fipronil photodegradation occurs via at least two distinct pathways, one of which involves desulfuration at the 4-position of the pyrazole ring giving the desulfinyl derivative and the other of which involves a different modification of the 4-substituent, leading to cleavage of the pyrazole ring and the formation of aniline derivatives. The latter compounds do not accumulate to high levels and may, therefore, be degraded further. The ecological significance of these results is discussed, particularly with regard to the insecticidal activity of the photoproducts.

  4. catena-Poly[[[trans-diaquabis(pyridine-κNcobalt(II]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-ylethylidene]hydrazino}benzoato-κ3O:N,N′-[bis(pyridine-κNcobalt(III]-μ-(4-{N′-[1-(3-acetyl-4-methyl-1H-pyrazol-5-ylethylidene]hydrazino}benzoato-κ3N,N′:O]perchlorate 3.66-hydrate

    Directory of Open Access Journals (Sweden)

    Igor O. Fritsky

    2008-02-01

    Full Text Available The title compound, {[Co2(C15H14N4O32(C5H5N4(H2O2]ClO4·3.66H2O}n, is a one-dimensional coordination polymer, with both CoII and CoIII centres in its structure. The ligand environment surrounding CoIII is formed by two N,N-chelating pyrazole-containing ligands and two pyridine molecules in axial positions. The high-spin CoII ions, situated at crystallographic centres of inversion, exhibit a distorted octahedral coordination mode. The ClO4− anion is linked to the polymer chain via hydrogen bonds. The chains are connected by hydrogen bonds to produce a three-dimensional structure.

  5. Accretion in Saturn's F Ring

    Science.gov (United States)

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

    2012-12-01

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

  6. Forandringslæring med autismediagnoser?

    DEFF Research Database (Denmark)

    Gustafson, Kari Ingrid; Mørck, Line Lerche

    2013-01-01

    Artiklen drøfter en række aktuelle spørgsmål omkring læring hos børn og unge med autisme-spektrum-forstyrrelses diagnoser. Der introduceres til en social praksisteoretisk forståelse af forandringslæring, der diskuterer forandring ikke kun i relation til en persons identitet, men også aktuelle og...... potentielle forandringer, når det gælder overskridelse af binær logik i autisme versus normalitet, samt i relation til at overskride individualiserede og dualistiske problem-forståelser af fejl og mangler ved det autistiske barn. Det illustreres, hvordan disse former for dualistisk tænkning er forankret i et...... Rasmus’ ændringer i læring, selvforståelse og tilhørsforhold perspektiveres med andre ASF-diagnostiseredes læring udforsket bl.a. gennem gruppeinterviews i regi af Asperger-foreningen. Artiklen byder således på et alternativ i form af at forstå forandringslæring som overskridende læring, med langt større...

  7. catena-Poly[[copper(II-bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl selenide

    Directory of Open Access Journals (Sweden)

    Maksym Seredyuk

    2009-11-01

    Full Text Available In the title compound, {[Cu(C10H14N4Se2](ClO42}n, the CuII ion is located on a twofold rotation axis and has a tetragonally distorted square-planar geometry constituted by four N atoms. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl selenide (L ligands bridges the copper centers into a polymeric chain extending along [001]. The perchlorate anions are involved in intermolecular N—H...O hydrogen bonding, which links the chains into layers parallel to the bc plane.

  8. Using Ring Strain to Control 4π-Electrocyclization Reactions: Torquoselectivity in Ring Closing of Medium-Ring Dienes and Ring Opening of Bicyclic Cyclobutenes.

    Science.gov (United States)

    Boon, Byron A; Green, Aaron G; Liu, Peng; Houk, K N; Merlic, Craig A

    2017-05-05

    Syntheses of strained cyclic dienes were accomplished via palladium(II)-catalyzed oxidative cyclizations of terminal bis(vinylboronate esters). The reactions generate strained (E,E)-1,3-dienes that undergo spontaneous 4π-electrocyclizations to form bicyclic cyclobutenes. Formation of the cyclobutenes is driven by the strain in the medium-ring (E,E)-1,3-diene intermediate. Thermal ring openings of the cyclobutenes give (Z,Z)-1,3-diene products, again for thermodynamic reasons. DFT calculations verified the thermodynamic versus kinetic control of the reactions, and kinetic studies are in excellent agreement with the calculated energy changes. An extension of the tandem coupling/4π-electrocyclization pathway was demonstrated by a palladium(II)-catalyzed oxidative homocoupling/8π-electrocyclization cascade.

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

    Science.gov (United States)

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

    2018-06-01

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

  10. Flux qubits on semiconducting quantum ring

    International Nuclear Information System (INIS)

    Szopa, M; Zipper, E

    2010-01-01

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

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

    CERN Document Server

    Amiri, Iraj Sadegh

    2014-01-01

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

  12. Iron Oxide-Supported Copper Oxide Nanoparticles (Nanocat-Fe-CuO): Magnetically Recyclable Catalysts for the Synthesis of Pyrazole Derivatives, 4-Methoxyaniline, and Ullmann-type Condensation Reactions

    Science.gov (United States)

    An efficient and benign protocol is reported for the synthesis of 4-methoxyaniline, medicinally important pyrazole derivatives, and Ullmann-type condensation reaction using magnetically separable and reusable magnetite-supported copper (nanocat-Fe-CuO) nanoparticles under mild co...

  13. Formation of a dinuclear copper(II) complex through the cleavage of CN bond of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole

    Energy Technology Data Exchange (ETDEWEB)

    Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia); Kassim, Mohammad B. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor, Malaysia and Fuel Cell Institute, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-(3-(pyridin-2-yl)-pyrazolato) and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the C{sub benzoyl}N bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the (3-(pyridin-2-yl)-pyrazolato)(3-(pyridin-2-yl)-1H-pyrazole)Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complex crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ε = 116 dm{sup 3} mol{sup −1} cm{sup −1}) supports the presence of Cu(II) centres.

  14. Ring rearrangements and reactivity of 3-((4-oxo-4H-chromen-3-ylmethylene-4-phenyl-1H-[1,5]benzodiazepin-2(3H-one toward some nucleophiles

    Directory of Open Access Journals (Sweden)

    Hanan Salah

    2017-05-01

    Full Text Available Condensation of 4-phenyl-1H-[1,5]benzodiazepin-2(3H-one (1 with 3-formylchromone (2 afforded a mixture of 3-(chromenylmethylene[1,5]benzodiazepinone 3 and 14-chromenylbenzodiazepino[2,3:6,5]pyrano[2,3-b]benzodiazepine 4. Ring rearrangements of compound 3 with different nucleophilic reagents, such as potassium hydroxide and/or ammonium acetate led to rearrangement into pyranobenzodiazepine 5 and pyridobenzodiazepine 6, respectively. Treatment of compound 3 with hydrazine hydrate, hydroxylamine hydrochloride, malononitrile, cyanothioacetamide, 2-cyano-3,3-disufanylacrylonitrile, and/or 2-cyano-3-phenylamino-3-sufanylacrylonitrile, has been carried out at different conditions, leading to versatile heterocyclic substituted benzodiazepines at position 3, viz. pyrazole 8, isoxazole 9, pyridines 10 and 11, 1,3-dithiine 12, and 1,3-thiazine 13 derivatives.

  15. Interaction of Vortex Ring with Cutting Plate

    Science.gov (United States)

    Musta, Mustafa

    2015-11-01

    The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.

  16. Synthesis and antitumor activity of some novel thiophene, pyrimidine, coumarin, pyrazole and pyridine derivatives

    Directory of Open Access Journals (Sweden)

    Albratty Mohammed

    2017-03-01

    Full Text Available 2-Cyano-N-(thiazol-2-yl acetamide (2a and 2-cyano-N-(oxazol- 2-yl acetamide (2b were obtained via the reaction of ethyl cyanoacetate with either 2-aminothiazole (1a or 2-aminooxazole (1b. The formed products were directed toward the reaction with cyclopentanone and elemental sulfur in the presence of triethylamine to give cyclopenta[b]thiophene derivatives (3a,b. The latter products were reacted with either ethyl cyanoacetate or malononitrile to form compounds 4a,b and 5a,b, respectively. Compounds 4a,b were aimed at synthesizing some heterocyclic compounds; thus internal cyclization reactions were introduced to form compounds 6a,b. Also, compounds 4a,b reacted with salicylaldehyde, hydrazine derivatives and either urea or thiourea to produce coumarin derivatives (7a,b, pyrazole derivatives (8a-d and pyrimidine derivatives (9a-d, respectively. Reaction of either benzaldehyde or benzene diazonium chloride (11 with compounds 4a,b afforded compounds 10a,b and 12a,b, respectively. On the other hand, compounds 5a,b underwent internal cyclization to form pyrimidine derivatives 13a,b. Also, when compounds 5a,b reacted with either ethyl cyanoacetate or malononitrile, they gave pyridine derivatives (15a-d through the formation of intermediates (14a-d. Finally, formation of fused pyrimidine derivatives (17a,b was achieved through the reaction of compounds 5a,b and salicylaldehyde applying two different pathways. The first pathway used a catalytic amount of piperidine to form compounds 16a,b; the latter products underwent cyclization to give compounds 17a,b. The second pathway, using a catalytic amount of sodium ethoxide solution directly in one step, afforded compounds 17a,b. Structures of the newly synthesized compounds were established using IR, 1H NMR, 13C NMR and mass spectrometry and their antitumor activity was investigated. Some of these compounds showed promising inhibitory effects on three different cell lines. However, fused pyrimidine

  17. Application of 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea as sensing material for construction of Tm{sup 3+}-PVC membrane sensor

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Feizyzadeh, Babak [Department of Applied Chemistry, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of); Faridbod, Farnoush; Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2011-10-10

    A thulium(III) membrane sensor was made using 2% sodium tetraphenyl borate (NaTPB), 65% dibutylphthalate (DBP), 30% poly(vinyl chloride) (PVC) and 3% 1-ethyl-3-(2,5-dihydro-4-(3,5-dimethyl-1H-pyrazol-4-yl) -5-oxo-1H-pyrazol-3-yl)thiourea (ET) as an ionophore. Conductometric study shows selectivity of the Et toward Tm{sup 3+} ions. Nernstian response of 19.6 {+-} 0.4 mV per decade of thulium concentration was observed, and the electrode worked well in concentration range of 1.0 x 10{sup -6} to 1.0 x 10{sup -2} mol L{sup -1} with a lower detection limit (LDL) of 7.2 x 10{sup -7} mol L{sup -1}, in a pH range of 4.3-10.4. The selectivity of the sensor over alkaline, alkaline earth, transition and heavy metal ions was also found to be in a satisfactory range. To check the analytical applicability of the proposed Tm{sup 3+} sensor, it was successfully used as an indicator electrode in analysis of thulium in certified reference materials. - Research highlights: {yields} This work reports development of polymeric membrane sensor for Tm3+ determination in certified reference materials. {yields} The novelty of this work is based on the high affinity of the ionophore toward the Tm3+ ions which causes the high selectivity of the sensor. {yields} The newly developed sensor is superior to the formerly reported Tm3+ sensors in terms of selectivity and detection limit.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-01

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

  19. catena-Poly[[copper(II)-bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide

    Science.gov (United States)

    Seredyuk, Maksym; Haukka, Matti; Pavlenko, Vadim A.; Fritsky, Igor O.

    2009-01-01

    In the title compound, {[Cu(C10H14N4Se)2](ClO4)2}n, the CuII ion is located on a twofold rotation axis and has a tetra­gonally distorted square-planar geometry constituted by four N atoms. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide (L) ligands bridges the copper centers into a polymeric chain extending along [001]. The perchlorate anions are involved in inter­molecular N—H⋯O hydrogen bonding, which links the chains into layers parallel to the bc plane. PMID:21578140

  20. Moving-ring field-reversed mirror reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1981-01-01

    We describe a first prototype fusion reactor design of the Moving-Ring Field-Reversed Mirror Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma. The plamsa rings, formed by a coaxial plasma gun, are magnetically compressed to ignition temperature while they are being injected into the reactor's burner section. DT ice pellets refuel the rings during the burn at a rate which maintains constant fusion power. A steady train of plasma rings moves at constant speed through the reactor under the influence of a slightly diverging magnetic field. The aluminum first wall and breeding zone structure minimize induced radioactivity; hands-on maintenance is possible on reactor components outside the breeding blanket. Helium removes the heat from the Li 2 O tritium breeding blanket and is used to generate steam. The reactor produces a constant, net power of 376 MW

  1. Rotating circular strings, and infinite non-uniqueness of black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto

    2004-01-01

    We present new self-gravitating solutions in five dimensions that describe circular strings, i.e., rings, electrically coupled to a two-form potential (as e.g., fundamental strings do), or to a dual magnetic one-form. The rings are prevented from collapsing by rotation, and they create a field analogous to a dipole, with no net charge measured at infinity. They can have a regular horizon, and we show that this implies the existence of an infinite number of black rings, labeled by a continuous parameter, with the same mass and angular momentum as neutral black rings and black holes. We also discuss the solution for a rotating loop of fundamental string. We show how more general rings arise from intersections of branes with a regular horizon (even at extremality), closely related to the configurations that yield the four-dimensional black hole with four charges. We reproduce the Bekenstein-Hawking entropy of a large extremal ring through a microscopic calculation. Finally, we discuss some qualitative ideas for a microscopic understanding of neutral and dipole black rings. (author)

  2. cyclo-Tetrakis(μ-3-acetyl-4-methyl-1H-pyrazole-5-carboxylato-κ4N2,O3:N1,O5tetrakis[aquacopper(II] tetradecahydrate

    Directory of Open Access Journals (Sweden)

    Sergey Malinkin

    2011-09-01

    Full Text Available The title compound, [Cu4(C7H6N2O34(H2O4]·14H2O, a tetranuclear [2 × 2] grid-type complex with S4 symmetry, contains four CuII atoms which are bridged by four pyrazolecarboxylate ligand anions and are additionally bonded to a water molecule. Each CuII atom is coordinated by two O atoms of the carboxylate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carboxylic acid and one O atom of a water molecule. The geometry at each CuII atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O—H...O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.

  3. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    1983-12-01

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

  4. RING STAR FORMATION RATES IN BARRED AND NONBARRED GALAXIES

    International Nuclear Information System (INIS)

    Grouchy, R. D.; Buta, R. J.; Salo, H.; Laurikainen, E.

    2010-01-01

    Nonbarred ringed galaxies are relatively normal galaxies showing bright rings of star formation in spite of lacking a strong bar. This morphology is interesting because it is generally accepted that a typical galactic disk ring forms when material collects near a resonance, set up by the pattern speed of a bar or bar-like perturbation. Our goal in this paper is to examine whether the star formation properties of rings are related to the strength of a bar or, in the absence of a bar, to the non-axisymmetric gravity potential in general. For this purpose, we obtained Hα emission line images and calculated the line fluxes and star formation rates (SFRs) for 16 nonbarred SA galaxies and four weakly barred SAB galaxies with rings. For comparison, we combine our new observations with a re-analysis of previously published data on five SA, seven SAB, and 15 SB galaxies with rings, three of which are duplicates from our sample. With these data, we examine what role a bar may play in the star formation process in rings. Compared to barred ringed galaxies, we find that the inner ring SFRs and Hα+[N II] equivalent widths in nonbarred ringed galaxies show a similar range and trend with absolute blue magnitude, revised Hubble type, and other parameters. On the whole, the star formation properties of inner rings, excluding the distribution of H II regions, are independent of the ring shapes and the bar strength in our small samples. We confirm that the deprojected axis ratios of inner rings correlate with maximum relative gravitational force Q g ; however, if we consider all rings, a better correlation is found when a local bar forcing at the radius of the ring, Q r , is used. Individual cases are described and other correlations are discussed. By studying the physical properties of these galaxies, we hope to gain a better understanding of their placement in the scheme of the Hubble sequence and how they formed rings without the driving force of a bar.

  5. GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS

    International Nuclear Information System (INIS)

    Yasui, Yuki; Ohtsuki, Keiji; Daisaka, Hiroshi

    2014-01-01

    Using a local N-body simulation, we examine gravitational accretion of ring particles onto moonlet cores in Saturn's rings. We find that gravitational accretion of particles onto moonlet cores is unlikely to occur in the C ring and probably difficult in the inner B ring as well provided that the cores are rigid water ice. Dependence of particle accretion on ring thickness changes when the radial distance from the planet and/or the density of particles is varied: the former determines the size of the core's Hill radius relative to its physical size, while the latter changes the effect of self-gravity of accreted particles. We find that particle accretion onto high-latitude regions of the core surface can occur even if the rings' vertical thickness is much smaller than the core radius, although redistribution of particles onto the high-latitude regions would not be perfectly efficient in outer regions of the rings such as the outer A ring, where the size of the core's Hill sphere in the vertical direction is significantly larger than the core's physical radius. Our results suggest that large boulders recently inferred from observations of transparent holes in the C ring are not formed locally by gravitational accretion, while propeller moonlets in the A ring would be gravitational aggregates formed by particle accretion onto dense cores. Our results also imply that the main bodies of small satellites near the outer edge of Saturn's rings may have been formed in rather thin rings

  6. GRAVITATIONAL ACCRETION OF PARTICLES ONTO MOONLETS EMBEDDED IN SATURN's RINGS

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Yuki; Ohtsuki, Keiji [Department of Earth and Planetary Sciences, Kobe University, Kobe 657-8501 (Japan); Daisaka, Hiroshi, E-mail: y.yasui@whale.kobe-u.ac.jp, E-mail: ohtsuki@tiger.kobe-u.ac.jp [Graduate School of Commerce and Management, Hitotsubashi University, Tokyo 186-8601 (Japan)

    2014-12-20

    Using a local N-body simulation, we examine gravitational accretion of ring particles onto moonlet cores in Saturn's rings. We find that gravitational accretion of particles onto moonlet cores is unlikely to occur in the C ring and probably difficult in the inner B ring as well provided that the cores are rigid water ice. Dependence of particle accretion on ring thickness changes when the radial distance from the planet and/or the density of particles is varied: the former determines the size of the core's Hill radius relative to its physical size, while the latter changes the effect of self-gravity of accreted particles. We find that particle accretion onto high-latitude regions of the core surface can occur even if the rings' vertical thickness is much smaller than the core radius, although redistribution of particles onto the high-latitude regions would not be perfectly efficient in outer regions of the rings such as the outer A ring, where the size of the core's Hill sphere in the vertical direction is significantly larger than the core's physical radius. Our results suggest that large boulders recently inferred from observations of transparent holes in the C ring are not formed locally by gravitational accretion, while propeller moonlets in the A ring would be gravitational aggregates formed by particle accretion onto dense cores. Our results also imply that the main bodies of small satellites near the outer edge of Saturn's rings may have been formed in rather thin rings.

  7. Synthesis, characterization and anticancer studies of new steroidal oxadiazole, pyrrole and pyrazole derivatives

    Directory of Open Access Journals (Sweden)

    Shamsuzzaman

    2015-07-01

    Full Text Available In the present study steroidal derivatives, 3β-[5′-mercapto-1′,3′,4′-oxadiazole-2-yl]methoxy cholest-5-ene 2, 3β-[2′,5′-dimethylpyrrole-1-yl]aminocarbonylmethoxycholest-5-ene 3 and 3β-[3′,5′-dimethyl pyrazole-1-yl]carbonylmethoxycholest-5-ene 4 have been synthesized from cholest-5-en-3β-O-acetyl hydrazide 1 using CS2/KOH, acetonyl acetone and acetyl acetone, respectively as reagents and are characterized by IR, 1H NMR,13C NMR, MS and elemental analysis. Compounds 2–4 were also evaluated for anticancer activity against human leukemia cell line (HL-60 by MTT assay and compound 4 displayed the promising behavior by showing better anticancer activity.

  8. 1-[3-(2-Benzyloxy-6-hydroxy-4-methylphenyl-5-[3,5-bis(trifluoromethylphenyl]-4,5-dihydro-1H-pyrazol-1-yl]propane-1-one

    Directory of Open Access Journals (Sweden)

    U. H. Patel

    2013-06-01

    Full Text Available In the title compound, C28H24F6N2O3, the mean plane of the central pyrazoline ring forms dihedral angles of 2.08 (9 and 69.02 (16° with the 2-benzyloxy-6-hydroxy-4-methylphenyl and 3,5-bis(trifluoromethylphenyl rings, respectively. The dihedral angle between the mean planes of the pyrazoline and 3,5-bis(trifluoromethylphenyl rings is 68.97 (9°. An intramolecular O—H...N hydrogen bond is observed, which forms an S(6 graph-set motif. In the crystal, pairs of weak C—H...F halogen interactions link the molecules into inversion dimers while molecular chains along [100] are formed by C—H...O contacts.

  9. Vibration of Elastic Functionally Graded Thick Rings

    Directory of Open Access Journals (Sweden)

    Guang-Hui Xu

    2017-01-01

    Full Text Available The free vibration behaviors of functionally graded rings were investigated theoretically. The material graded in the thickness direction according to the power law rule and the rings were assumed to be in plane stress and plane strain states. Based on the first-order shear deformation theory and the kinetic relation of von Kárman type, the frequency equation for free vibration of functionally graded ring was derived. The derived results were verified by those in literatures which reveals that the present theory can be appropriate to predict the free vibration characteristics for quite thick rings with the radius-to-thickness ratio from 60 down to 2.09. Comparison between the plane stress case and the plane strain case indicates a slight difference. Meanwhile, the effects of the structural dimensional parameters and the material inhomogeneous parameter are examined. It is interesting that the value of the logarithmic form of vibration frequency is inversely proportional to the logarithmic form of the radius-to-thickness ratio or the mean radius.

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

    Science.gov (United States)

    Grydlik, Martyna; Brehm, Moritz; Schäffler, Friedrich

    2012-10-30

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

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

    Directory of Open Access Journals (Sweden)

    Holger F. Bettinger

    2013-04-01

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

  12. Mechanical seal having a double-tier mating ring

    Science.gov (United States)

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  13. Computerspil og læring

    Directory of Open Access Journals (Sweden)

    Lasse Juel Larsen

    2015-02-01

    Full Text Available Game-based learning og gamification er ord, der ofte optræder i forbindelse med computerspil og læring. Denne artikel vil analytisk undersøge, hvordan computerspil og læring går i forbindelse med hinanden. Artikel tager afsæt i Gregory Batesons læringsteori og læser denne igennem det kommercielle computerspil StarCraft 2 fra Blizzard Intertainment. Batesons læringsteori vil ikke alene blive gennemgået, men også udvidet og perspektiveret.  Formålet med denne indsats er at skabe et afsæt, der kan demonstrere, hvordan læring foregår i computerspil. Herefter vil afsættet blive anvendt til at destillere et læringsteoretisk udkast. Artiklen falder således i to dele, hvor den første analytisk adresserer, hvordan læring i computerspil foregår, mens den anden er teoriproducerende på baggrund af resultaterne fra første del.

  14. Rings with involution whose symmetric elements are central

    Directory of Open Access Journals (Sweden)

    Taw Pin Lim

    1980-01-01

    Full Text Available In a ring R with involution whose symmetric elements S are central, the skew-symmetric elements K form a Lie algebra over the commutative ring S. The classification of such rings which are 2-torsion free is equivalent to the classification of Lie algebras K over S equipped with a bilinear form f that is symmetric, invariant and satisfies [[x,y],z]=f(y,zx−f(z,xy. If S is a field of char ≠2, f≠0 and dimK>1 then K is a semisimple Lie algebra if and only if f is nondegenerate. Moreover, the derived algebra K′ is either the pure quaternions over S or a direct sum of mutually orthogonal abelian Lie ideals of dim≤2.

  15. A spin-crossover complex based on a 2,6-bis(pyrazol-1-yl)pyridine (1-bpp) ligand functionalized with a carboxylate group.

    Science.gov (United States)

    Abhervé, Alexandre; Clemente-León, Miguel; Coronado, Eugenio; Gómez-García, Carlos J; López-Jordà, Maurici

    2014-07-07

    Combining Fe(ii) with the carboxylate-functionalized 2,6-bis(pyrazol-1-yl)pyridine (bppCOOH) ligand results in the spin-crossover compound [Fe(bppCOOH)2](ClO4)2 which shows an abrupt spin transition with a T1/2 of ca. 380 K and a TLIESST of 60 K due to the presence of a hydrogen-bonded linear network of complexes.

  16. Influence of feed rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, Chao; van den Boogaard, Antonius H.; Omerspahic, E.; Recina, V.; Geijselaers, Hubertus J.M.; Ishikawa, T.; Mori, K.-I.

    2014-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries. Under some process conditions, defects such as

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-15

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

  19. Stability Constants of Some Biologically Important Pyrazoles and Their Ni2+ Complexes in Different Dielectric Constant of Medium

    Directory of Open Access Journals (Sweden)

    S. D. Deosarkar

    2012-01-01

    Full Text Available The proton-ligand stability constants of some biologically important new pyrazoles and formation constants of their complexes with Ni(II were determined at 0.1 mol dm-3 ionic strength and at 303.15 K in different dielectric constant of dioxane-water mixture by potentiometric method. The Calvin-Bjerrum's pH-titration technique as used by Irving and Rossotti was used for determination of stability constants. The results enabled to study the electrostatic forces of attraction between metal ion and ligand with changes in dielectric constant of the medium.

  20. Cytoplasmic tethering of a RING protein RBCK1 by its splice variant lacking the RING domain

    International Nuclear Information System (INIS)

    Yoshimoto, Nobuo; Tatematsu, Kenji; Koyanagi, Tomoyoshi; Okajima, Toshihide; Tanizawa, Katsuyuki; Kuroda, Shun'ichi

    2005-01-01

    RBCC protein interacting with PKC 1 (RBCK1) is a transcription factor belonging to the RING-IBR protein family and has been shown to shuttle between the nucleus and cytoplasm, possessing both the nuclear export and localization signals within its amino acid sequence. RBCK2, lacking the C-terminal half of RBCK1 including the RING-IBR domain, has also been identified as an alternative splice variant of RBCK1. RBCK2 shows no transcriptional activity and instead it represses the transcriptional activity of RBCK1. Here, we show that RBCK2 is present usually in the cytoplasm containing two Leu-rich regions that presumably serve as a nuclear export signal (NES). Moreover, an NES-disrupted RBCK1 that is mostly localized within the nucleus is translocated to the cytoplasm when coexpressed with RBCK2, suggesting that RBCK2 serves as a cytoplasmic tethering protein for RBCK1. We propose a novel and general function of RING-lacking splice variants of RING proteins to control the intracellular localization and functions of the parental RING proteins by forming a hetero-oligomeric complex

  1. Aquabis(3,5-dimethyl-1H-pyrazole-κN(oxalato-κ2O,O′copper(II

    Directory of Open Access Journals (Sweden)

    Andrii I. Buvailo

    2008-01-01

    Full Text Available In the title compound, [Cu(C2O4(C5H8N22(H2O], the CuII atom is coordinated in a slightly distorted square-pyramidal geometry by two N atoms belonging to the two 3,5-dimethyl-1H-pyrazole ligands, two O atoms of the oxalate anion providing an O,O′-chelating coordination mode, and an O atom of the water molecule occupying the apical position. The crystal packing shows a well defined layer structure. Intra-layer connections are realised through a system of hydrogen bonds while the nature of the inter-layer interactions is completely hydrophobic, including no hydrogen-bonding interactions.

  2. Synthesis, biological evaluation and molecular docking of novel 5-phenyl-1H-pyrazol derivatives as potential BRAF(V600E) inhibitors.

    Science.gov (United States)

    Dong, Jing-Jun; Li, Qing-Shan; Wang, Shu-Fu; Li, Cui-Yun; Zhao, Xin; Qiu, Han-Yue; Zhao, Meng-Yue; Zhu, Hai-Liang

    2013-10-07

    The RAF-MEK-ERK cascade appears to be intimately involved in the regulation of cell cycle progression and apoptosis. The BRAF(V600E) mutant results in constitutive activation of the ERK pathway, which can lead to cellular growth dysregulation. A series of 5-phenyl-1H-pyrazol derivatives (3a-5e) have been designed and synthesized, and their biological activities were evaluated as potential BRAF(V600E) inhibitors. All the compounds were reported for the first time except 3e, and compound 1-(4-bromo-2-hydroxybenzyl)-3-phenyl-1-(5-phenyl-1H-pyrazol-3-yl)urea (5c) displayed the most potent inhibitory activity (BRAF(V600E) IC50 = 0.19 μM). Antiproliferative assay results indicated that compound 5c possessed high antiproliferative activity against cell lines WM266.4 and A375 in vitro, with IC50 values of 1.50 and 1.32 μM, respectively, which were comparable with the positive control vemurafenib. Docking simulations showed that compound 5c binds tightly to the BRAF(V600E) active site and acts as BRAF(V600E) inhibitor. A 3D-QSAR model was also built to provide more pharmacophore understanding towards designing new agents with more potent BRAF(V600E) inhibitory activity.

  3. Vapour pressures of 1-methyl derivatives of benzimidazole, pyrazole and indole. The energy of the intermolecular hydrogen bond N-H⋯N

    International Nuclear Information System (INIS)

    Almeida, Ana R.R.P.; Monte, Manuel J.S.

    2014-01-01

    Highlights: • Vapour pressures of 1-methyl derivatives of benzimidazole, pyrazole and indole. • Enthalpies, entropies and Gibbs free energies of sublimation/vaporisation were derived. • Temperatures and enthalpies of fusion were determined. • Energy of the intermolecular hydrogen bond N-H⋯N was estimated. - Abstract: The vapour pressures of the liquid phase of 1-methylpyrazole, 1-methylbenzimidazole and 1-methylindole were measured over the temperature ranges (253.9 to 293.3) K, (303.2 to 372.5) K, and (268.6 to 341.9) K, respectively, using a static method. The vapour pressures of the crystalline phase of the two latter compounds were also measured at temperatures between (301.2 to 328.9) K and (267.6 to 275.5) K, respectively. The results obtained enabled the determination of the standard molar enthalpies and entropies of sublimation and of vaporisation at the mean temperatures of the measurements and at T = 298.15 K. The temperatures and molar enthalpies of fusion were determined using differential scanning calorimetry. The enthalpies of the intermolecular hydrogen bonds N-H⋯N in the crystalline phase of benzimidazole and pyrazole were determined and compared with the result previously determined for the energy of the intermolecular hydrogen bond in crystalline imidazole

  4. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

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

  5. Synthesis, optical properties and application of a set of novel pyrazole nopinone derivatives

    Science.gov (United States)

    Yang, Jinlai; Xu, Xu; Rui, Jian; Wang, Zhonglong; Zhang, Yan; Wang, Shifa; Wu, Liangru

    2017-08-01

    Pyrazole derivatives (4-6) were directly synthesized from β-pinene derivative nopinone, and they were characterized by Fourier transform infrared (FTIR) spectoscope, nuclear magnetic resonance (NMR), and mass spectrometry. Their optical properties were investigated by ultraviolet-visible spectroscopy and fluorescence spectroscopy. The three compounds emitted strong blue fluorescence in ethanol. Using a fluorescence quenching method, compound 4 could be used to detect the content (100.57%) of copper sulfate pentahydrate (≥ 99%) with a RSD of 1.98%, y = - 0.1127 × + 2.7148, R2 = 0.9703 (Cu2 +: 0.5-8.0 × 10- 5 mol/L), and compounds 4-6 also had utility of calculating the content of anhydrous ferric chloride at a wide range of concentration. Thus, compounds 4-6 are new functional fluorescents for detecting the content of some purchased products.

  6. Dependency of the regio- and stereoselectivity of intramolecular, ring-closing glycosylations upon the ring size

    Directory of Open Access Journals (Sweden)

    Patrick Claude

    2011-12-01

    Full Text Available Phenyl 3,4,6-tri-O-benzyl-2-O-(3-carboxypropionyl-1-thio-β-D-galactopyranoside (1 was condensed via its pentafluorophenyl ester 2 with 5-aminopentyl (4a, 4-aminobutyl (4b, 3-aminopropyl (4c and 2-aminoethyl 4,6-O-benzylidene-β-D-glucopyranoside (4d, prepared from the corresponding N-Cbz protected glucosides 3a–d, to give the corresponding 2-[3-(alkylcarbamoylpropionyl] tethered saccharides 5a–d. Intramolecular, ring closing glycosylation of the saccharides with NIS and TMSOTf afforded the tethered β(1→3 linked disaccharides 6a–c, the α(1→3 linked disaccharides 7a–d and the α(1→2 linked disaccharide 8d in ratios depending upon the ring size formed during glycosylation. No β(1→2 linked disaccharides were formed. Molecular modeling of saccharides 6–8 revealed that a strong aromatic stacking interaction between the aromatic parts of the benzyl and benzylidene protecting groups in the galactosyl and glucosyl moieties was mainly responsible for the observed regioselectivity and anomeric selectivity of the ring-closing glycosylation step.

  7. Three-dimensional parallel vortex rings in Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Crasovan, Lucian-Cornel; Perez-Garcia, Victor M.; Danaila, Ionut; Mihalache, Dumitru; Torner, Lluis

    2004-01-01

    We construct three-dimensional structures of topological defects hosted in trapped wave fields, in the form of vortex stars, vortex cages, parallel vortex lines, perpendicular vortex rings, and parallel vortex rings, and we show that the latter exist as robust stationary, collective states of nonrotating Bose-Einstein condensates. We discuss the stability properties of excited states containing several parallel vortex rings hosted by the condensate, including their dynamical and structural stability

  8. Connections between Star Cluster Populations and Their Host Galaxy Nuclear Rings

    Science.gov (United States)

    Ma, Chao; de Grijs, Richard; Ho, Luis C.

    2018-04-01

    Nuclear rings are excellent laboratories for probing diverse phenomena such as the formation and evolution of young massive star clusters and nuclear starbursts, as well as the secular evolution and dynamics of their host galaxies. We have compiled a sample of 17 galaxies with nuclear rings, which are well resolved by high-resolution Hubble and Spitzer Space Telescope imaging. For each nuclear ring, we identified the ring star cluster population, along with their physical properties (ages, masses, and extinction values). We also determined the integrated ring properties, including the average age, total stellar mass, and current star formation rate (SFR). We find that Sb-type galaxies tend to have the highest ring stellar mass fraction with respect to the host galaxy, and this parameter is correlated with the ring’s SFR surface density. The ring SFRs are correlated with their stellar masses, which is reminiscent of the main sequence of star-forming galaxies. There are striking correlations between star-forming properties (i.e., SFR and SFR surface density) and nonaxisymmetric bar parameters, appearing to confirm previous inferences that strongly barred galaxies tend to have lower ring SFRs, although the ring star formation histories turn out to be significantly more complicated. Nuclear rings with higher stellar masses tend to be associated with lower cluster mass fractions, but there is no such relation for the ages of the rings. The two youngest nuclear rings in our sample, NGC 1512 and NGC 4314, which have the most extreme physical properties, represent the young extremity of the nuclear ring age distribution.

  9. 1-[3-(2-Methyl-4-phenylquinolin-3-yl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]-propane-1-one

    Directory of Open Access Journals (Sweden)

    Allaoua Kedjadja

    2015-06-01

    Full Text Available A novel compound, 1-[3-(2-methyl-4-phenylquinolin-3-yl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]-propane-1-one (3 has been synthesized by cyclocondensation of (E-1-(2-methyl-4-phenylquinolin-3-yl-3-phenylprop-2-en-1-one (2 and hydrazine hydrate in propionic acid. The structure of this compound was established by elemental analysis, IR, 1H-NMR, 13C-NMR and MS data.

  10. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-01

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

  11. Nano-organocatalyst: magnetically retrievable ferrite-anchored glutathione for microwave-assisted Paal–Knorr reaction, aza-Michael addition, and pyrazole synthesis

    KAUST Repository

    Polshettiwar, Vivek; Varma, Rajender S.

    2010-01-01

    Postsynthetic Surface modification of magnetic nanoparticles by glutathione imparts desirable chemical functionality and enables the generation of catalytic sites on the surfaces of ensuing organocatalysts. In this article, we discuss the developments, unique activity, and high selectivity of nano-organocatalysts for microwave-assisted Paal-Knorr reaction, aza-Michael addition, and pyrazole synthesis. Their insoluble character Coupled with paramagnetic nature enables easy separation of these nano-catalysts from the reaction mixture using external magnet, which eliminates the requirement of catalyst filtration. Published by Elsevier Ltd.

  12. Conceptual design of a moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C.; Carlson, G.A.; Ashworth, C.P.

    1986-01-01

    A design of a prototype moving-ring reactor was completed, and a development plan for a pilot reactor is outlined. The fusion fuel is confined in current-carrying rings of magnetically field-reversed plasma (''compact toroids''). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three ''burn stations.'' Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for one-third of the total burn time at each station. Deuterium-tritium- 3 He ice pellets refuel the rings at a rate that maintains constant radiated power. The fusion power per ring is approx. =105.5 MW. The burn time to reach a fusion energy gain of Q = 30 is 5.9 s

  13. Report of the eRHIC Ring-Ring Working Group

    Energy Technology Data Exchange (ETDEWEB)

    Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-13

    This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

  14. Vanishing of cohomology over Cohen–Macaulay rings

    DEFF Research Database (Denmark)

    Christensen, Lars Winther; Holm, Henrik Granau

    2012-01-01

    A 2003 counterexample to a conjecture of Auslander brought attention to a family of rings—colloquially called AC rings—that satisfy a natural condition on vanishing of cohomology. Several results attest to the remarkable homological properties of AC rings, but their definition is barely operational......, and it remains unknown if they form a class that is closed under typical constructions in ring theory. In this paper, we study transfer of the AC property along local homomorphisms of Cohen–Macaulay rings. In particular, we show that the AC property is preserved by standard procedures in local algebra. Our...

  15. Acceleration of compact torus plasma rings in a coaxial rail-gun

    International Nuclear Information System (INIS)

    Hartman, C.W.; Hammer, J.H.; Eddleman, J.

    1986-01-01

    They discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub Theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

  16. Acceleration of compact torus plasma rings in a coaxial rail-gun

    International Nuclear Information System (INIS)

    Hartman, C.W.; Hammer, J.H.; Eddleman, J.

    1985-01-01

    We discuss here theoretical studies of magnetic acceleration of Compact Torus plasma rings in a coaxial, rail-gun accelerator. The rings are formed using a magnetized coaxial plasma gun and are accelerated by injection of B/sub theta/ flux from an accelerator bank. After acceleration, the rings enter a focusing cone where the ring is decelerated and reduced in radius. As the ring radius decreases, the ring magnetic energy increases until it equals the entering kinetic energy and the ring stagnates. Scaling laws and numerical calculations of acceleration using a O-D numerical code are presented. 2-D, MHD simulations are shown which demonstrate ring formation, acceleration, and focusing. Finally, 3-D calculations are discussed which determine the ideal MHD stability of the accelerated ring

  17. Differences in hepatic microsomal cytochrome P-450 isoenzyme induction by pyrazole, chronic ethanol, 3-methylcholanthrene, and phenobarbital in high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats.

    Science.gov (United States)

    Lucas, D; Ménez, J F; Berthou, F; Cauvin, J M; Deitrich, R A

    1992-10-01

    High and low alcohol sensitivity (HAS and LAS) rats have been selected for their differences in ethanol-induced sleep time. Liver monooxygenase activities were studied in HAS and LAS rats before and after treatments with known inducers such as chronic ethanol, pyrazole, 3-methylcholanthrene (3-MC) and phenobarbital (PB) to determine whether the selection procedure also selected for differences in the cytochrome P-450 (P-450) inducibility. This previously has been shown with long sleep (LS) and short sleep (SS) mice, which were selected using a similar criterion. 3-MC and PB, in conjunction with chronic ethanol treatment, were used in order to evaluate the interactions of ethanol with these inducers. Prior to treatment, total P-450 content was slightly lower in LAS than in HAS rats. However, both lines displayed the same microsomal monooxygenase activities related to different P-450 isozymes. This was demonstrated by ethoxyresorufin deethylation (EROD) for cytochrome P-450 1A1 (CYP1A1), acetanilide hydroxylation (ACET) for CYP1A2, pentoxyresorufin dealkylation (PROD) for CYP2B, 1-butanol oxidation (BUTAN) and N-nitrosodimethylamine demethylation (NDMA) for CYP2E1. After the different treatments, HAS rats did not differ from LAS rats in their CYP2E1 inducibility. However, pyrazole, PB and 3-MC treatment led to differences in CYP1A and CYP2B monooxygenase activities between the two lines. The enhancement of PROD by pyrazole treatment was less prominent in LAS (1.7-fold of the control value) than in HAS rats (3.8-fold).(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Common pass decentered annular ring resonator

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, D. A.; Waite, T. R.

    1985-04-30

    An optical resonator having an annular cylindrical gain region for use in a chemical laser or the like in which two ring-shaped mirrors having substantially conical reflecting surfaces are spaced apart along a common axis of revolution of the respective conical surfaces. A central conical mirror reflects incident light directed along said axis radially outwardly to the reflecting surface of a first one of the ring-shaped mirrors. The radial light rays are reflected by the first ring mirror to the second ring mirror within an annular cylindrical volume concentric with said common axis and forming a gain region. Light rays impinging on the second ring mirror are reflected to diametrically opposite points on the same conical mirror surfaces and back to the first ring mirror through the same annular cylindrical volume. The return rays are then reflected by the conical mirror surface of the first ring mirror back to the central conical mirror. The mirror surfaces are angled such that the return rays are reflected back along the common axis by the central mirror in a concentric annular cylindrical volume. A scraper mirror having a central opening centered on said axis and an offset opening reflects all but the rays passing through the two openings in an output beam. The rays passing through the second opening are reflected back through the first opening to provide feedback.

  19. Hybrid plasmonic waveguide-assisted Metal–Insulator–Metal ring resonator for refractive index sensing

    Science.gov (United States)

    Butt, M. A.; Khonina, S. N.; Kazanskiy, N. L.

    2018-05-01

    A highly sensitive refractive index sensor based on an integrated hybrid plasmonic waveguide (HPWG) and a Metal-Insulator-Metal (M-I-M) micro-ring resonator is presented. In our design, there are two slot-waveguide-based micro-rings that encircle a gold disc. The outer slot WG is formed by the combination of Silicon-Air-Gold ring and the inner slot-waveguide is formed by Gold ring-Air-Gold disc. The slot-waveguide rings provide an interaction length sufficient to accumulate a detectable wavelength shift. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). The sensitivity of this micro-ring resonator is achieved at 800 nm/RIU which is about six times higher than that of the conventional Si ring with the same geometry. Our proposed sensor design has a potential to find further applications in biomedical science and nano-photonic circuits.

  20. TREE SELECTING AND TREE RING MEASURING IN DENDROCHRONOLOGICAL INVESTIGATIONS

    Directory of Open Access Journals (Sweden)

    Sefa Akbulut

    2004-04-01

    Full Text Available Dendrochronology is a method of dating which makes use of the annual nature of tree growth. Dendrochronology may be divided into a number of subfields, each of which covers one or more aspects of the use of tree ring data: dendroclimatology, dendrogeomorphology, dendrohydrology, dendroecology, dendroarchaelogy, and dendrogylaciology. Basic of all form the analysis of the tree rings. The wood or tree rings can aid to dating past events about climatology, ecology, geology, hydrology. Dendrochronological studies are conducted either on increment cores or on discs. It may be seen abnormalities on tree rings during the measurement like that false rings, missing rings, reaction wood. Like that situation, increment cores must be extracted from four different sides of each tree and be studied as more as on tree.

  1. (4Z-4-[1-(2-Aminoanilinoethylidene]-3-methyl-1-phenyl-4,5-dihydro-1H-pyrazol-5-one

    Directory of Open Access Journals (Sweden)

    Mohamed Samba

    2017-02-01

    Full Text Available The conformation of the title compound, C18H18N4O, is partly determined by an intramolecular N—H...O hydrogen bond that imposes planarity on the central aminoethylidene-3-methylpyrazol-5-one segment of the molecule. In the crystal, N—H...O hydrogen and N—H...N hydrogen bonds both form centrosymmetric dimers that enclose R22(18 rings. These, together with C—H...N and π–π stacking interactions between centrosymmetrically related pyrazalone rings, stack the molecules along the b-axis direction.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  3. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

    Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  5. Light-Ring Stability for Ultracompact Objects

    Science.gov (United States)

    Cunha, Pedro V. P.; Berti, Emanuele; Herdeiro, Carlos A. R.

    2017-12-01

    We prove the following theorem: axisymmetric, stationary solutions of the Einstein field equations formed from classical gravitational collapse of matter obeying the null energy condition, that are everywhere smooth and ultracompact (i.e., they have a light ring) must have at least two light rings, and one of them is stable. It has been argued that stable light rings generally lead to nonlinear spacetime instabilities. Our result implies that smooth, physically and dynamically reasonable ultracompact objects are not viable as observational alternatives to black holes whenever these instabilities occur on astrophysically short time scales. The proof of the theorem has two parts: (i) We show that light rings always come in pairs, one being a saddle point and the other a local extremum of an effective potential. This result follows from a topological argument based on the Brouwer degree of a continuous map, with no assumptions on the spacetime dynamics, and, hence, it is applicable to any metric gravity theory where photons follow null geodesics. (ii) Assuming Einstein's equations, we show that the extremum is a local minimum of the potential (i.e., a stable light ring) if the energy-momentum tensor satisfies the null energy condition.

  6. Bosonic and fermionic dipoles on a ring

    DEFF Research Database (Denmark)

    Zöllner, Sascha; Pethick, C. J.; Bruun, Georg Morten

    2011-01-01

    We show that dipolar bosons and fermions confined in a quasi-one-dimensional ring trap exhibit a rich variety of states because their interaction is inhomogeneous. For purely repulsive interactions, with increasing strength of the dipolar coupling there is a crossover from a gaslike state...... to an inhomogeneous crystal-like one. For small enough angles between the dipoles and the plane of the ring, there are regions with attractive interactions, and clustered states can form....

  7. Robust gap repair in the contractile ring ensures timely completion of cytokinesis.

    OpenAIRE

    Silva, AM; Osório, DS; Pereira, AJ; Maiato, H; Pinto, IM; Rubinstein, B; Gassmann, R; Telley, IA; Carvalho, AX

    2016-01-01

    Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an acti...

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

    Science.gov (United States)

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

    2010-10-01

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

  9. Conference on Recent Advances in Commutative Ring and Module Theory & Conference on Rings and Polynomials

    CERN Document Server

    Frisch, Sophie; Glaz, Sarah; Tartarone, Francesca; Zanardo, Paolo

    2017-01-01

    This volume presents a collection of articles highlighting recent developments in commutative algebra and related non-commutative generalizations. It also includes an extensive bibliography and lists a substantial number of open problems that point to future directions of research in the represented subfields. The contributions cover areas in commutative algebra that have flourished in the last few decades and are not yet well represented in book form. Highlighted topics and research methods include Noetherian and non-Noetherian ring theory, module theory and integer-valued polynomials along with connections to algebraic number theory, algebraic geometry, topology and homological algebra. Most of the eighteen contributions are authored by attendees of the two conferences in commutative algebra that were held in the summer of 2016: “Recent Advances in Commutative Ring and Module Theory,” Bressanone, Italy; “Conference on Rings and Polynomials”  Graz, Austria. There is also a small collection of invite...

  10. Faglig læring, social læring og evaluering i skolen

    DEFF Research Database (Denmark)

    Rasmussen, Annette; Rasmussen, Palle

    2010-01-01

    I det moderne samfunds skole foregår der en dobbelt social læring. På den ene side er en social dannelse, især orienteret mod medborgerskab og demokratisk deltagelse, en del af skolens formål. På den anden side lægger skolens rammer og kultur og kultur ofte op til passivitet og konformitet. I art...

  11. ring mellem elever

    DEFF Research Database (Denmark)

    Georgsen, Marianne; Davidsen, Jacob

    2010-01-01

    I denne rapport præsenteres resultater fra følgeforskningen til projektet Læring gennem Bevægelse, som er gennemført på Søndervangskolen i Hammel i perioden august 2009 - maj 2010. Projektet er gennemført i samspil mellem lærere, it-vejleder, elever og skolens ledelse. Projektets overordnede formål...

  12. Antitumor potential of 1-thiocarbamoyl-3,5-diaryl-4,5-dihydro-1H-pyrazoles in human bladder cancer cells.

    Science.gov (United States)

    Tessmann, Josiane Weber; Buss, Julieti; Begnini, Karine Rech; Berneira, Lucas Moraes; Paula, Favero Reisdorfer; de Pereira, Claudio Martin Pereira; Collares, Tiago; Seixas, Fabiana Kömmling

    2017-10-01

    Bladder cancer is a genitourinary malignant disease common worldwide. Current chemotherapy is often limited mainly due to toxicity and drug resistance. Thus, there is a continued need to discover new therapies. Recently evidences shows that pyrazoline derivatives are promising antitumor agents in many types of cancers, but there are no studies with bladder cancer. In order to find potent and novel chemotherapy drugs for bladder cancer, a series of pyrazoline derivatives 2a-2d were tested for their antitumor activity in two human bladder cancer cell lines 5647 and T24. The MTT assay showed that the compounds 1-thiocarbamoyl-3,5-diphenyl-4,5-dihydro-1H-pyrazole (2a) and 1-thiocarbamoyl-5-(4-chlorophenyl)-3-phenyl-4,5-dihydro-1H-pyrazole (2c) decrease the cell viability of 5637 cells. Molecular modeling indicated that these compounds had a good oral bioavailability and low toxicities. Clonogenic assay and flow cytometric analysis were used to assess colony formation, apoptosis induction and cell cycle distribution. Overall, our results suggest that pyrazoline 2a and 2c, with the substituents hydrogen and chlorine respectively, may decrease cell viability and colony formation of bladder cancer 5637 cell line by inhibition of cell cycle progression, and for pyrazoline 2a, by induction of apoptosis. As indicated by the physicochemical properties of these compounds, the steric factor influences the activity. Therefore, these pyrazoline derivatives can be considered promising anticancer agents for the treatment of bladder cancer. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Contact mechanical analysis of O-ring stresses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kyu

    2007-02-15

    The purpose of this project is to develop the approximate solutions of contact traction and internal stress of an O-ring by using a two dimensional elasticity for enhancing the design and failure prediction technology. Investigated were the applicability of Lindley's formulae of contact force prediction and the Hertz theory. Three cases of O-ring installation were considered. The approximate solution of contact tractions and internal stresses of each case were derived. The key results are summarized as follows: 1. It is verified that Lindley's formulae predicts the relationship between the fractional compression and contact force. 2. In the case of Case I, II and III without internal pressure, it is found that a function form of the contact traction is the Hertzian. So it is possible to express the traction with a Hertzian form and correction factors. 3. The internal stresses are derived in the case of the Hertzian traction profile. The stresses at the center of O-ring show a satisfactory result when compared with the finite element result.

  14. The Case for Massive and Ancient Rings of Saturn

    Science.gov (United States)

    Esposito, Larry W.

    2016-04-01

    Analysis of Voyager and Pioneer 11 results give a mass for Saturn's rings, M = 5 x 10-8 Msat. This is about the mass of Saturn's small moon Mimas. This has been interpreted as a lower limit to the ring mass (Esposito et al 1983), since the thickest parts of the rings were not penetrated by the stellar occultstion, and this calculation assumes an unvarying particle size throughout the rings. Because the rings are constantly bombarded by micrometeroids, their current composition of nearly pure water ice implies such low mass rings must have formed recently. The case is par-ticularly strong for Saturn's A ring, where the data are the best, implying the A ring is less than 10% of the age of the Saturn (Esposito 1986). Cassini results com-pound this problem. UVIS spectra are consistent with either young rings or rings about 10x as massive as the Voyager estimate (Elliott and Esposito (2011). CDA confirms the impacting mass flux is similar to that as-sumed for the pollution calculations (Kempf etal 2015). VIMS analysis of density wave signatures in the B ring gives a value of about 1/3 the Voyager value (Hedmann etal 2016). This VIMS result implies the rings are even younger! The problem is that young rings are very unlikely to be formed recently, meaning that we live in a very special epoch, following some unlikely recent origin… like disruption of a medium sized moon or capture of the fragments of a disrupted comet. This paradox (Charnoz etal 2009) is unre-solved. Alternative interpretations: To take the VIMS results at face value, Saturn's low mass rings must be very young. The optically thick B ring must be made of small, porous or fractal particles. This is hard to understand, since the particles are continually colliding every few hours and temporary aggregates will stir the collision velocities to higher values. An alternative is that we accept the higher mass interpretation of the Pioneer 11 results (Esposito etal 2008) using the granola bar model of Colwell

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  16. Unexpected formation and crystal structure of tetrakis(1H-pyrazole-κN2palladium(II dichloride

    Directory of Open Access Journals (Sweden)

    Thomas Wagner

    2014-12-01

    Full Text Available The title salt, [Pd(C3H4N24]Cl2, was obtained unexpectedly by the reaction of palladium(II dichloride with equimolar amounts of 1-chloro-1-nitro-2,2,2-tris(pyrazolylethane in methanol solution. The Pd2+ cation is located on an inversion centre and has a square-planar coordination sphere defined by four N atoms of four neutral pyrazole ligands. The average Pd—N distance is 2.000 (2 Å. The two chloride anions are not coordinating to Pd2+. They are connected to the complex cations through N—H...Cl hydrogen bonds. In addition, C—H...Cl hydrogen bonds are observed, leading to a three-dimensional linkage of cations and anions.

  17. Growth of planetisimals in a gaseous ring

    International Nuclear Information System (INIS)

    Hourigan, K.

    1981-01-01

    The aggregation of planetesimals in a gaseous ring leads to the development of a dominant body amongst the planetesimal population. The presence of the gas in the form of a differentially rotating ring serves to constrain the orbits of the planetesimals and grains to within a thin toroidal region through the action of gas drag. This situation allows for the efficient aggregation of bodies and, as a result of the low resultant relative velocites, the minimization of collisional fragmentation effects

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

    Science.gov (United States)

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

    2017-12-01

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

  19. 5-[(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H-dione

    Directory of Open Access Journals (Sweden)

    Salman A. Khan

    2010-03-01

    Full Text Available The title compound, 5-[(3,5-dimethyl-1-phenyl-1H-pyrazol-4-ylmethylene]-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H-dione, has been synthesized by condensation of 1,3-diethyl-2-thiobarbituric acid and 3,5-dimethyl-1-phenylpyrazole-4-carbaldehyde in ethanol in the presence of pyridine. The structure of this new compound was confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and EI-MS spectral analysis.

  20. (2E-3-(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Salman A. Khan

    2010-04-01

    Full Text Available The title compound, (2E-3-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one (3 was synthesized in high yield by aldol condensation of 3-acetyl-2,5-dimethylthiophene and 3,5-dimethyl-1-phenylpyrazole-4-carboxaldehyde in ethanolic NaOH at room temperature. Its structure was fully characterized by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.

  1. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  2. Heterocyclic Analogues of Xanthone and Xanthione. 1H-Pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones and Thiones: Synthesis and NMR Data

    Directory of Open Access Journals (Sweden)

    Wolfgang Holzer

    2010-09-01

    Full Text Available The synthesis of the title compounds is described. Reaction of 1-substituted 2-pyrazolin-5-ones with 5-chloro-1-phenyl-1H-pyrazole-4-carbonyl chloride or 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbonyl chloride, respectively, using calcium hydroxide in refluxing 1,4-dioxane gave the corresponding 4-heteroaroylpyrazol-5-ols, which were cyclized into 1H-pyrano[2,3-c:6,5-c]dipyrazol-4(7H-ones by treatment with K2CO3/DMF. The latter were converted into the corresponding thiones upon reaction with Lawesson’s reagent. Detailed NMR spectroscopic investigations (1H, 13C, 15N of the ring systems and their precursors are presented.

  3. Ring laser frequency biasing mechanism

    International Nuclear Information System (INIS)

    McClure, R.E.

    1975-01-01

    A ring laser cavity including a magnetically saturable member for differentially phase shifting the contradirectional waves propagating in the laser cavity, the phase shift being produced by the magneto-optic interaction occurring between the light waves and the magnetization in the cavity forming component as the light waves are reflected therefrom is described

  4. Anti-Candida, Anti-Enzyme Activity and Cytotoxicity of 3,5-Diaryl-4,5-dihydro-1H-pyrazole-1-carboximidamides

    Directory of Open Access Journals (Sweden)

    Simone Oliveira

    2014-05-01

    Full Text Available Because of the need for more effective and less harmful antifungal therapies, and interest in the synthesis of new carboximidamides, the goal of this study was to determine the antifungal and anti-enzyme activities of some new pyrazole carboximidamides and their cytotoxicity. For this purpose, tests were performed to evaluate: minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC; production of proteinases and phospholipase, and cytotoxicity of the extracts. Data were analyzed by ANOVA and Tukey Tests (α = 5%. The results were: MIC and MFC ≥ 62.5 μg/mL (C. albicans, C. parapsilosis, C. famata, C. glabrata, and Rhodotorula mucillaginosa and MIC and MFC ≥ 15.6 μg/mL (C. lipolytica. The values of proteinase and phospholipase (Pz of C. albicans before and after exposure to the compounds were: 0.6 (±0.024 and 0.2 (±0.022 and 0.9 (±0.074 and 0.3 (±0.04, respectively. These proteinase results were not significant (p = 0.69, but those of phospholipase were (p = 0.01, and 15.6 μg/mL was the most effective concentration. The cytotoxicity means were similar among the tests (p = 0.32. These compounds could be useful as templates for further development through modification or derivatization to design more potent antifungal agents. Data from this study provide evidence that these new pyrazole formulations could be an alternative source for the treatment of fungal infections caused by Candida. However, a specific study on the safety and efficacy of these in vivo and clinical trials is still needed, in order to evaluate the practical relevance of the in vitro results.

  5. Surface emitting ring quantum cascade lasers for chemical sensing

    Science.gov (United States)

    Szedlak, Rolf; Hayden, Jakob; Martín-Mateos, Pedro; Holzbauer, Martin; Harrer, Andreas; Schwarz, Benedikt; Hinkov, Borislav; MacFarland, Donald; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Acedo, Pablo; Lendl, Bernhard; Strasser, Gottfried

    2018-01-01

    We review recent advances in chemical sensing applications based on surface emitting ring quantum cascade lasers (QCLs). Such lasers can be implemented in monolithically integrated on-chip laser/detector devices forming compact gas sensors, which are based on direct absorption spectroscopy according to the Beer-Lambert law. Furthermore, we present experimental results on radio frequency modulation up to 150 MHz of surface emitting ring QCLs. This technique provides detailed insight into the modulation characteristics of such lasers. The gained knowledge facilitates the utilization of ring QCLs in combination with spectroscopic techniques, such as heterodyne phase-sensitive dispersion spectroscopy for gas detection and analysis.

  6. Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

    2010-12-01

    Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  7. STRUCTURAL STUDY OF BIS(2,6-BIS(PYRAZOL-3-YLPYRIDINENICKEL(II BY CALORIMETRY AND EXAFS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Kristian H Sugiyarto

    2010-06-01

    Full Text Available The main aim of this work is to reveal the complex formation of 2,6-bis(pyrazol-3-ylpyridine, bpp, with nickel(II perchlorate in DMF by calorimetric stepwise complex formation and then followed by EXAFS spectrometry. It was found that the complex formation follows two stepwise pathways namely the formation of mono pyrazolyl-pyridine, [Ni(DMF3 bpp]2+, and bis pyrazolyl-pyridine, [Ni(bpp2]2+;  the formation constants being  log β1 = 6.57, and log β2 = 5.02, and the total value of log β  = 11.58. The final formation of six-coordinated compound was confirmed by EXAFS analysis with the mean Ni-Nbpp bond length of 2.0646(0.0014 Å.   Keywords: nickel(II, bpp, EXAFS

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

    Science.gov (United States)

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

    2011-09-02

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

  9. Kinetics of tracheid development explain conifer tree-ring structure.

    Science.gov (United States)

    Cuny, Henri E; Rathgeber, Cyrille B K; Frank, David; Fonti, Patrick; Fournier, Meriem

    2014-09-01

    Conifer tree rings are generally composed of large, thin-walled cells of light earlywood followed by narrow, thick-walled cells of dense latewood. Yet, how wood formation processes and the associated kinetics create this typical pattern remains poorly understood. We monitored tree-ring formation weekly over 3 yr in 45 trees of three conifer species in France. Data were used to model cell development kinetics, and to attribute the relative importance of the duration and rate of cell enlargement and cell wall deposition on tree-ring structure. Cell enlargement duration contributed to 75% of changes in cell diameter along the tree rings. Remarkably, the amount of wall material per cell was quite constant along the rings. Consequently, and in contrast with widespread belief, changes in cell wall thickness were not principally attributed to the duration and rate of wall deposition (33%), but rather to the changes in cell size (67%). Cell enlargement duration, as the main driver of cell size and wall thickness, contributed to 56% of wood density variation along the rings. This mechanistic framework now forms the basis for unraveling how environmental stresses trigger deviations (e.g. false rings) from the normal tree-ring structure. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  10. Synthesis, characterization and antibacterial activity of some 5-aryl-1, 3-Diphenyl 1-4, 5-dihydro-1H-Pyrazoles

    International Nuclear Information System (INIS)

    Al-Bahtiti, Nawal Hassan

    2007-01-01

    The condensation of acetophenone (I) with arylaldehyde (II) was investigated and the resulting chalcones 2-Arylidene 1-Acetophenone (III) were reacted with phenyl hydrazine and acetic acid to produce substituted 5-aryl-1, 3-diphenyl-4, 5-dihydro-1H-Pyrazoles (IV). The structures of all products were studied by H-NMR, IR, thermal and elemental analysis. Thermo-gravimetric (TG) and differential thermal analysis (DTA) was applied to investigate the thermal behavior and structure of the synthesized compounds. 2-Pyrazolines (IV) exhibited moderate activity against Streptococcus faecalis ATCC 19433, Klebsiella pneumoniae ATCC 13883, Proteus vulgaris ATCC 25922, Shigella sonnei ATCC 25931 and Peseudom oaeruginosa ATCC 27853. (author)

  11. Exact wave functions of two-electron quantum rings.

    Science.gov (United States)

    Loos, Pierre-François; Gill, Peter M W

    2012-02-24

    We demonstrate that the Schrödinger equation for two electrons on a ring, which is the usual paradigm to model quantum rings, is solvable in closed form for particular values of the radius. We show that both polynomial and irrational solutions can be found for any value of the angular momentum and that the singlet and triplet manifolds, which are degenerate, have distinct geometric phases. We also study the nodal structure associated with these two-electron states.

  12. Laser plasma focus produced in a ring target

    International Nuclear Information System (INIS)

    Saint-Hilaire, G.; Szili, Z.

    1976-01-01

    A new geometry for generating a laser-produced plasma is presented. A toroidal mirror is used to focus a CO 2 laser beam on the inside wall of a copper ring target. The plasma produced converges at the center of the ring where an axial plasma focus is formed. High-speed photography shows details of a plasma generated at a distance from the target surface. This new geometry could have important applications in the field of x-ray lasers

  13. Development of dapivirine vaginal ring for HIV prevention.

    Science.gov (United States)

    Devlin, Bríd; Nuttall, Jeremy; Wilder, Susan; Woodsong, Cynthia; Rosenberg, Zeda

    2013-12-01

    In the continuing effort to develop effective HIV prevention methods for women, a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine is currently being tested in two safety and efficacy trials. This paper reviews dapivirine ring's pipeline development process, including efforts to determine safe and effective dosing levels as well as identify delivery platforms with the greatest likelihood of success for correct and consistent use. Dapivirine gel and other formulations were developed and tested in preclinical and clinical studies. Multiple vaginal ring prototypes were also tested, resulting in the current ring design as well as additional designs under consideration for future testing. Efficacy results from clinical trials are expected in 2015. Through ongoing consultations with national regulatory authorities, licensure requirements for dapivirine vaginal ring approval have been defined. This article is based on a presentation at the "Product Development Workshop 2013: HIV and Multipurpose Prevention Technologies," held in Arlington, Virginia on February 21-22, 2013. It forms part of a special supplement to Antiviral Research. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Modification, biological evaluation and 3D QSAR studies of novel 2-(1,3-diaryl- 4,5-dihydro-1H-pyrazol-5-ylphenol derivatives as inhibitors of B-Raf kinase.

    Directory of Open Access Journals (Sweden)

    Yu-Shun Yang

    Full Text Available A series of novel 2-(1,3-diaryl- 4,5-dihydro-1H-pyrazol-5-ylphenol derivatives (C1-C24 have been synthesized. The B-Raf inhibitory activity and anti-proliferation activity of these compounds have been tested. Compound C6 displayed the most potent biological activity against B-RafV600E (IC50 = 0.15 µM and WM266.4 human melanoma cell line (GI50 = 1.75 µM, being comparable with the positive control (Vemurafenib and Erlotinib and more potent than our previous best compounds. The docking simulation was performed to analyze the probable binding models and poses while the QSAR model was built to check the previous work as well as to introduce new directions. This work aimed at seeking more potent inhibitors as well as discussing some previous findings. As a result, the introduction of ortho-hydroxyl group on 4,5-dihydro-1H-pyrazole skeleton did reinforce the anti-tumor activity while enlarging the group on N-1 of pyrazoline was also helpful.

  15. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

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

  16. Primitivity and weak distributivity in near rings and matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-08-01

    This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

  17. The effect of surface pressure modification on the speed of vortex rings

    Energy Technology Data Exchange (ETDEWEB)

    Partridge, Matthew; Davis, Frank; Higson, Seamus P J [Centre of Biomedical Imaging, Cranfield University, Cranfield MK43 0AL (United Kingdom); James, Stephen W; Tatam, Ralph P, E-mail: f.davis@cranfield.ac.uk [Engineering Photonics, School of Engineering, Cranfield University, Cranfield MK43 0AL (United Kingdom)

    2014-10-01

    A series of experiments investigating the relationship between surface pressure, monolayer elasticity and the speed of vortex rings is presented. A drop of water, when touched to the surface of a larger body of water, will coalesce and form a vortex ring that moves perpendicularly to the surface of the water. The speed of the vortex ring movement away from the surface of the water has been seen to be sensitive to the presence of monolayer materials. Here we explore the influence of four monolayer forming materials, stearic acid, tricosanoic acid, 4-tert butyl calix[4]arene and calix[4]resorcarene (C11), on the properties of vortex rings. For each material, the speed of the vortex rings through the water was measured at a range of surface pressures. The speed was found to increase in a linear fashion until surface pressures greater than 30 mN m{sup −1}, where the ring’s speed decreased towards the value measured in the absence of a monolayer. Analysis of the results suggests a future route toward a better understanding of the mechanisms involved.

  18. Experimental and computational approaches to the analysis of the molecular structure of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile

    Science.gov (United States)

    Al-Azmi, Amal; Shalaby, Mona Abbas

    2018-03-01

    A green, fast and straightforward procedure for the synthesis of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile is described in this paper. The method uses a coupling reaction between 4- nitrophenyl diazonium chloride and 5-aminopyrazole-4-carbonitrile. The structure is confirmed by different spectroscopic studies such as IR, NMR, HRMS and UV-vis spectroscopy in addition to X-ray single-crystal determination. The molecular geometry, vibrational frequencies and gauge-invariant atomic orbital (GIAO) 1H and 13C NMR chemical shift values of (E)-3-(3-(4-nitrophenyl)triaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile are calculated in the ground state using the Hartree-Fock (HF) method and density functional theory (DFT) with the 6-31G(d) basis set, and are compared with the experimental data. The natural bond orbital (NBO) analysis is performed so as to discuss the stability of the molecule that arises from hyper conjugative interactions and charge delocalization. The electronic properties, such as HOMO and LUMO energies, were calculated using time dependent density functional theory (TD-DFT) approach.

  19. Origin and dynamics of vortex rings in drop splashing.

    Science.gov (United States)

    Lee, Ji San; Park, Su Ji; Lee, Jun Ho; Weon, Byung Mook; Fezzaa, Kamel; Je, Jung Ho

    2015-09-04

    A vortex is a flow phenomenon that is very commonly observed in nature. More than a century, a vortex ring that forms during drop splashing has caught the attention of many scientists due to its importance in understanding fluid mixing and mass transport processes. However, the origin of the vortices and their dynamics remain unclear, mostly due to the lack of appropriate visualization methods. Here, with ultrafast X-ray phase-contrast imaging, we show that the formation of vortex rings originates from the energy transfer by capillary waves generated at the moment of the drop impact. Interestingly, we find a row of vortex rings along the drop wall, as demonstrated by a phase diagram established here, with different power-law dependencies of the angular velocities on the Reynolds number. These results provide important insight that allows understanding and modelling any type of vortex rings in nature, beyond just vortex rings during drop splashing.

  20. Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Xue Jukui

    2005-01-01

    The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

  1. Antimicrobial activities of pyridinium-tailored pyrazoles bearing 1,3,4-oxadiazole scaffolds

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    2017-11-01

    Full Text Available Herein, a series of pyridinium-tailored 5-trifluoromethylpyrazoles containing 1,3,4-oxadiazole moieties were constructed through coupling key pharmaceutical fragments of pyridinium, pyrazole, and 1,3,4-oxadiazole scaffolds in single molecular architecture. Antimicrobial results suggested that this kind of compounds exhibited significant activities against three types of pathogenic bacteria and six fungal strains in vitro. The minimal EC50 values of designed compounds against Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri could reach to 0.467, 1.04, and 0.600 μg/mL, respectively, through tuning and optimizing N-substituents, bridging atom, and alkyl length of the tailor. Antifungal assays revealed that all title molecules possessed considerable activity against Botrytis cinerea with the minimal EC50 value up to 2.71 μg/mL; and compounds I-8, I-10, I-12, II-12, and IV-12 showed the strongest growth suppression toward Rhizoctonia solani with EC50 values ranging from 10.2 to 24.0 μg/mL. Given the above results, this kind of compounds could serve as new lead compounds in the research of antimicrobial chemotherapy.

  2. Ring-Opening Polymerization of Lactides by (Pyrazol-1-ylmethyl ...

    African Journals Online (AJOL)

    NICO

    2014-09-03

    Sep 3, 2014 ... An excellent example of such a biodegradable polymer is polylactide ... 2.1. Materials. All air-sensitive manipulations were performed under argon ... lated by filtration and dried to constant weight prior to analy- ses by NMR ...

  3. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

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

  4. Wake patterns behind boulders in the rings of Saturn

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  6. Transparent arrays of silver nanowire rings driven by evaporation of sessile droplets

    Science.gov (United States)

    Wang, Xiaofeng; Kang, Giho; Seong, Baekhoon; Chae, Illkyeong; Teguh Yudistira, Hadi; Lee, Hyungdong; Kim, Hyunggun; Byun, Doyoung

    2017-11-01

    A coffee-ring pattern can be yielded on the three-phase contact line following evaporation of sessile droplets with suspended insoluble solutes, such as particles, DNA molecules, and mammalian cells. The formation of such coffee-ring, together with their suppression has been applied in printing and coating technologies. We present here an experimental study on the assembly of silver nanowires inside an evaporating droplet of a colloidal suspension. The effects of nanowire length and concentration on coffee-ring formation of the colloidal suspension were investigated. Several sizes of NWs with an aspect ratio between 50 and 1000 were systematically investigated to fabricate coffee-ring patterns. Larger droplets containing shorter nanowires formed clearer ring deposits after evaporation. An order-to-disorder transition of the nanowires’ alignment was found inside the rings. A printing technique with the evaporation process enabled fabrication of arrays of silver nanowire rings. We could manipulate the patterns silver nanowire rings, which might be applied to the transparent and flexible electrode.

  7. Transparent arrays of silver nanowire rings driven by evaporation of sessile droplets

    International Nuclear Information System (INIS)

    Wang, Xiaofeng; Kang, Giho; Seong, Baekhoon; Chae, Illkyeong; Yudistira, Hadi Teguh; Lee, Hyungdong; Byun, Doyoung; Kim, Hyunggun

    2017-01-01

    A coffee-ring pattern can be yielded on the three-phase contact line following evaporation of sessile droplets with suspended insoluble solutes, such as particles, DNA molecules, and mammalian cells. The formation of such coffee-ring, together with their suppression has been applied in printing and coating technologies. We present here an experimental study on the assembly of silver nanowires inside an evaporating droplet of a colloidal suspension. The effects of nanowire length and concentration on coffee-ring formation of the colloidal suspension were investigated. Several sizes of NWs with an aspect ratio between 50 and 1000 were systematically investigated to fabricate coffee-ring patterns. Larger droplets containing shorter nanowires formed clearer ring deposits after evaporation. An order-to-disorder transition of the nanowires’ alignment was found inside the rings. A printing technique with the evaporation process enabled fabrication of arrays of silver nanowire rings. We could manipulate the patterns silver nanowire rings, which might be applied to the transparent and flexible electrode. (paper)

  8. Robust gap repair in the contractile ring ensures timely completion of cytokinesis.

    Science.gov (United States)

    Silva, Ana M; Osório, Daniel S; Pereira, Antonio J; Maiato, Helder; Pinto, Inês Mendes; Rubinstein, Boris; Gassmann, Reto; Telley, Ivo Andreas; Carvalho, Ana Xavier

    2016-12-19

    Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure. © 2016 Silva et al.

  9. Multicolor Graphic Picture With Original Ring Raster Element

    Directory of Open Access Journals (Sweden)

    Jana Ziljak Vujic

    2006-12-01

    Full Text Available This paper deals with graphics and color rastering using new raster forms as well as raster combinations in vector anda pixel graphics, with combining both graphics in the same document. The unwanted increase or decrease of color coverage depends most of all on the fringe volume length bordering the raster element. The idea of this research work is to find a form alters in the least extent the raster element fringe volume in respect to its increase or decrease. The innovation in this research work is not only in the fact that the raster element's volume is altered in the minimal degree, but also that it does not change at all with the covering capacity increase or decrease. The solution led in the direction of creating such a raster element that has at least two independent shells where one increases in size together with the raster element increase, and the other one decreases when the raster element size increases. We have named this raster form as the ring form due to its similarity with a classical smooth ring.

  10. Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species.

    Science.gov (United States)

    Monahan, William B; Pereira, Ricardo J; Wake, David B

    2012-03-12

    In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes). Predicted barriers separate into two distinct categories: (i) single cohesive barriers (barriers - formed by groups of barriers (each 184,000 to 1.7 million km2) in close geographic proximity (totaling 1.9 to 2.3 million km2) - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus)). When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i) requires no a priori information on the relative importance of features that define barriers, (ii) can be replicated using any kind of continuously distributed environmental variable, and (iii) generates spatially explicit hypotheses of

  11. Tablets, læring og nye forretningsmodeller

    DEFF Research Database (Denmark)

    Andersen, Pernille Viktoria Kathja

    2011-01-01

    D. 6 oktober satte Netværk om E-Læring (NoEL) i samarbejde med InVIO fokus på Tablet-computing igennem et heldagsarrangement i Aalborg Universitets nye omgivelser på Nyhavnsgade 14. Formålet med dagen var, at stille skarpt på tablet formatet og udforske potentialerne og udfordringerne med særligt...... vægt på iPads til mobillæring og nye forretningsmodeller. Tablet –computing er de seneste år blevet mere og mere udbredt indenfor både uddannelse, arbejdsliv og i fritiden. Ønsket for dagen var derfor at bidrage med diskussion og videndeling omkring, hvad den nye håndholdte touch teknologi kommer til...... at betyde for læring, samarbejde og forretningsmodeller og dermed hvilke nye vilkår tablet computing kan bidrage med indenfor arbejdsliv og uddannelse....

  12. Influencing factors on the size uniformity of self-assembled SiGe quantum rings grown by molecular beam epitaxy.

    Science.gov (United States)

    Cui, J; Lv, Y; Yang, X J; Fan, Y L; Zhong, Z; Jiang, Z M

    2011-03-25

    The size uniformity of self-assembled SiGe quantum rings, which are formed by capping SiGe quantum dots with a thin Si layer, is found to be greatly influenced by the growth temperature and the areal density of SiGe quantum dots. Higher growth temperature benefits the size uniformity of quantum dots, but results in low Ge concentration as well as asymmetric Ge distribution in the dots, which induces the subsequently formed quantum rings to be asymmetric in shape or even broken somewhere in the ridge of rings. Low growth temperature degrades the size uniformity of quantum dots, and thus that of quantum rings. A high areal density results in the expansion and coalescence of neighboring quantum dots to form a chain, rather than quantum rings. Uniform quantum rings with a size dispersion of 4.6% and an areal density of 7.8×10(8) cm(-2) are obtained at the optimized growth temperature of 640°C.

  13. Rings in drugs.

    Science.gov (United States)

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

    2014-07-24

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

  14. Resting state networks' corticotopy: the dual intertwined rings architecture.

    Directory of Open Access Journals (Sweden)

    Salma Mesmoudi

    Full Text Available How does the brain integrate multiple sources of information to support normal sensorimotor and cognitive functions? To investigate this question we present an overall brain architecture (called "the dual intertwined rings architecture" that relates the functional specialization of cortical networks to their spatial distribution over the cerebral cortex (or "corticotopy". Recent results suggest that the resting state networks (RSNs are organized into two large families: 1 a sensorimotor family that includes visual, somatic, and auditory areas and 2 a large association family that comprises parietal, temporal, and frontal regions and also includes the default mode network. We used two large databases of resting state fMRI data, from which we extracted 32 robust RSNs. We estimated: (1 the RSN functional roles by using a projection of the results on task based networks (TBNs as referenced in large databases of fMRI activation studies; and (2 relationship of the RSNs with the Brodmann Areas. In both classifications, the 32 RSNs are organized into a remarkable architecture of two intertwined rings per hemisphere and so four rings linked by homotopic connections. The first ring forms a continuous ensemble and includes visual, somatic, and auditory cortices, with interspersed bimodal cortices (auditory-visual, visual-somatic and auditory-somatic, abbreviated as VSA ring. The second ring integrates distant parietal, temporal and frontal regions (PTF ring through a network of association fiber tracts which closes the ring anatomically and ensures a functional continuity within the ring. The PTF ring relates association cortices specialized in attention, language and working memory, to the networks involved in motivation and biological regulation and rhythms. This "dual intertwined architecture" suggests a dual integrative process: the VSA ring performs fast real-time multimodal integration of sensorimotor information whereas the PTF ring performs multi

  15. Resting State Networks' Corticotopy: The Dual Intertwined Rings Architecture

    Science.gov (United States)

    Mesmoudi, Salma; Perlbarg, Vincent; Rudrauf, David; Messe, Arnaud; Pinsard, Basile; Hasboun, Dominique; Cioli, Claudia; Marrelec, Guillaume; Toro, Roberto; Benali, Habib; Burnod, Yves

    2013-01-01

    How does the brain integrate multiple sources of information to support normal sensorimotor and cognitive functions? To investigate this question we present an overall brain architecture (called “the dual intertwined rings architecture”) that relates the functional specialization of cortical networks to their spatial distribution over the cerebral cortex (or “corticotopy”). Recent results suggest that the resting state networks (RSNs) are organized into two large families: 1) a sensorimotor family that includes visual, somatic, and auditory areas and 2) a large association family that comprises parietal, temporal, and frontal regions and also includes the default mode network. We used two large databases of resting state fMRI data, from which we extracted 32 robust RSNs. We estimated: (1) the RSN functional roles by using a projection of the results on task based networks (TBNs) as referenced in large databases of fMRI activation studies; and (2) relationship of the RSNs with the Brodmann Areas. In both classifications, the 32 RSNs are organized into a remarkable architecture of two intertwined rings per hemisphere and so four rings linked by homotopic connections. The first ring forms a continuous ensemble and includes visual, somatic, and auditory cortices, with interspersed bimodal cortices (auditory-visual, visual-somatic and auditory-somatic, abbreviated as VSA ring). The second ring integrates distant parietal, temporal and frontal regions (PTF ring) through a network of association fiber tracts which closes the ring anatomically and ensures a functional continuity within the ring. The PTF ring relates association cortices specialized in attention, language and working memory, to the networks involved in motivation and biological regulation and rhythms. This “dual intertwined architecture” suggests a dual integrative process: the VSA ring performs fast real-time multimodal integration of sensorimotor information whereas the PTF ring performs multi

  16. Algebra and Arithmetic of Modular Forms

    DEFF Research Database (Denmark)

    Rustom, Nadim

    In [Rus14b] and [Rus14a], we study graded rings of modular forms over congruence subgroups, with coefficients in subrings A of C, and determine bounds of the weights of modular forms constituting a minimal set of generators, as well as on the degree of the generators of the ideal of relations...... between them. We give an algorithm that computes the structures of these rings, and formulate conjectures on the minimal generating weight for modular forms with coefficients in Z. We discuss questions of finiteness of systems of Hecke eigenvalues modulo pm, for a prime p and an integer m ≥ 2, in analogy...

  17. Heat transfer behaviors in round tube with conical ring inserts

    International Nuclear Information System (INIS)

    Promvonge, P.

    2008-01-01

    To increase convection heat transfer in a uniform heat flux tube by a passive method, several conical rings used as turbulators are mounted over the test tube. The effects of the conical ring turbulator inserts on the heat transfer rate and friction factor are experimentally investigated in the present work. Conical rings with three different diameter ratios of the ring to tube diameter (d/D = 0.5, 0.6, 0.7) are introduced in the tests, and for each ratio, the rings are placed with three different arrangements (converging conical ring, referred to as CR array, diverging conical ring, DR array and converging-diverging conical ring, CDR array). In the experiment, cold air at ambient condition for Reynolds numbers in a range of 6000-26,000 is passed through the uniform heat flux circular tube. It is found that the ring to tube diameter ratio and the ring arrays provide a significant effect on the thermal performance of the test tube. The experimental results demonstrate that the use of conical ring inserts leads to a higher heat transfer rate than that of the plain surface tube, and the DR array yields a better heat transfer than the others. The results are also correlated in the form of Nusselt number as a function of Reynolds number, Prandtl number and diameter ratio. An augmentation of up to 197%, 333%, and 237% in Nusselt number is obtained in the turbulent flow for the CR, DR and CDR arrays, respectively, although the effect of using the conical ring causes a substantial increase in friction factor

  18. Black rings and the physical process version of the first law of thermodynamics

    International Nuclear Information System (INIS)

    Rogatko, Marek

    2005-01-01

    We consider the problem of the physical process version of the first law of black ring thermodynamics in n-dimensional Einstein gravity with additional (p+1)-form field strength and dilaton fields. The first order variations of mass, angular momentum and local charge for black ring are derived. From them we prove the physical process version of the first law of thermodynamic for stationary black rings

  19. EVOLUTION OF A RING AROUND THE PLUTO–CHARON BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States)

    2015-08-10

    We consider the formation of satellites around the Pluto–Charon binary. An early collision between the two partners likely produced the binary and a narrow ring of debris, out of which arose the moons Styx, Nix, Kerberos, and Hydra. How the satellites emerged from the compact ring is uncertain. Here we show that a particle ring spreads from physical collisions and collective gravitational scattering, similar to migration. Around a binary, these processes take place in the reference frames of “most circular” orbits, akin to circular ones in a Keplerian potential. Ring particles damp to these orbits and avoid destructive collisions. Damping and diffusion also help particles survive dynamical instabilities driven by resonances with the binary. In some situations, particles become trapped near resonances that sweep outward with the tidal evolution of the Pluto–Charon binary. With simple models and numerical experiments, we show how the Pluto–Charon impact ring may have expanded into a broad disk, out of which grew the circumbinary moons. In some scenarios, the ring can spread well beyond the orbit of Hydra, the most distant moon, to form a handful of smaller satellites. If these small moons exist, New Horizons will find them.

  20. Ordered quantum-ring chains grown on a quantum-dot superlattice template

    International Nuclear Information System (INIS)

    Wu Jiang; Wang, Zhiming M.; Holmes, Kyland; Marega, Euclydes; Mazur, Yuriy I.; Salamo, Gregory J.

    2012-01-01

    One-dimensional ordered quantum-ring chains are fabricated on a quantum-dot superlattice template by molecular beam epitaxy. The quantum-dot superlattice template is prepared by stacking multiple quantum-dot layers and quantum-ring chains are formed by partially capping quantum dots. Partially capping InAs quantum dots with a thin layer of GaAs introduces a morphological change from quantum dots to quantum rings. The lateral ordering is introduced by engineering the strain field of a multi-layer InGaAs quantum-dot superlattice.

  1. IDEALS GENERATED BY LINEAR FORMS AND SYMMETRIC ALGEBRAS

    Directory of Open Access Journals (Sweden)

    Gaetana Restuccia

    2016-01-01

    Full Text Available We consider ideals generated by linear forms in the variables X1 : : : ;Xn in the polynomial ring R[X1; : : : ;Xn], being R a commutative, Noetherian ring with identity. We investigate when a sequence a1; a2; : : : ; am of linear forms is an ssequence, in order to compute algebraic invariants of the symmetric algebra of the ideal I = (a1; a2; : : : ; am.

  2. Spacer type mediated tunable spin crossover (SCO) characteristics of pyrene decorated 2,6-bis(pyrazol-1-yl)pyridine (bpp) based Fe(ii) molecular spintronic modules.

    Science.gov (United States)

    Kumar, Kuppusamy Senthil; Šalitroš, Ivan; Moreno-Pineda, Eufemio; Ruben, Mario

    2017-08-14

    A simple "isomer-like" variation of the spacer group in a set of Fe(ii) spin crossover (SCO) complexes designed to probe spin state dependence of electrical conductivity in graphene-based molecular spintronic junctions led to the observation of remarkable variations in the thermal- and light-induced magnetic characteristics, paving a simple route for the design of functional SCO complexes with different temperature switching regimes based on a 2,6-bis(pyrazol-1-yl)pyridine ligand skeleton.

  3. Numerical simulation of fuel mixing with air in laminar buoyant vortex rings

    International Nuclear Information System (INIS)

    Prasad, M. Jogendra; Sundararajan, T.

    2016-01-01

    Highlights: • At large Reynolds number, small vortex ring is formed due to thin boundary layer. • At higher stroke to diameter ratio, larger vortex is formed which travels farther. • After formation, trailing stem transfers circulation and fuel to the ring by buoyancy. • Formation number of buoyant vortex ring is higher than that of non-buoyant ring. • Buoyant fuel puffs entrain more air than non-buoyant air-premixed fuel puffs. - Abstract: The formation and evolution of vortex rings consisting of methane-air mixtures have been numerically simulated for different stroke to diameter (L/D) ratios (1.5, 3.5 and 6), Reynolds numbers (1000 and 2000) and initial mixture compositions (fuel with 0%, 15% and 30% of stoichiometric air). The numerical simulations are first validated by comparing with the results of earlier computational studies and also with in-house data from smoke visualization studies. In pure methane case, buoyancy significantly aids the upward rise of the vortex ring. The increase of vortex core height with time is faster for larger L/D ratio, contributed mainly by the larger initial puff volume. The radial size of the vortex also increases rapidly with time during the formation stage; this is followed by a slight shrinkage when piston comes to a stop. Later, a slow radial growth of the ring occurs due to the entrainment of ambient air, except during vortex pinch-off. The boundary layer thickness δ_e at orifice exit decreases as Re"−"0"."5 at a fixed L/D ratio; this in turn, results in a vortex of smaller size and circulation level, at a relatively higher Reynolds number. For L/D values greater than the critical value, a trailing stem is formed behind the ring vortex which feeds circulation and fuel into the vortex ring in the later stages of vortex evolution. Mass fraction contours indicate that fuel-air mixing is more effective within the vortex than in the stem. Ambient air entrainment is larger at higher L/D ratio and lower Re, for the

  4. The small displacement elastic solution to the ball-on-ring testing method

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund

    2012-01-01

    The ball-on-ring experiment is used for testing of the biaxial strength of ceramics. In this work the solution for the stress distribution and displacements of the disc specimen in the ball-on-ring experiment are determined on closed form. The solution comprises the displacement field and its...

  5. Toxicological evaluation of two novel bitter modifying flavour compounds: 3-(1-((3,5-dimethylisoxazol-4-ylmethyl-1H-pyrazol-4-yl-1-(3-hydroxybenzylimidazolidine-2,4-dione and 3-(1-((3,5-dimethylisoxazol-4-ylmethyl-1H-pyrazol-4-yl-1-(3-hydroxybenzyl-5,5-dimethylimidazolidine-2,4-dione

    Directory of Open Access Journals (Sweden)

    Donald S. Karanewsky

    Full Text Available A toxicological evaluation of two novel bitter modifying flavour compounds, 3-(1-((3,5-dimethylisoxazol-4-ylmethyl-1H-pyrazol-4-yl-1-(3-hydroxybenzylimidazolidine-2,4-dione (S6821, CAS 1119831-25-2 and 3-(1-((3,5-dimethylisoxazol-4-ylmethyl-1H-pyrazol-4-yl-1-(3-hydroxybenzyl-5,5-dimethylimidazolidine-2,4-dione (S7958, CAS 1217341-48-4, were completed for the purpose of assessing their safety for use in food and beverage applications. S6821 undergoes oxidative metabolism in vitro, and in rat pharmacokinetic studies both S6821 and S7958 are rapidly converted to the corresponding O-sulfate and O-glucuronide conjugates. S6821 was not found to be mutagenic or clastogenic in vitro, and did not induce micronuclei in bone marrow polychromatic erythrocytes in vivo. S7958, a close structural analog of S6821, was also found to be non-mutagenic in vitro. In short term and subchronic oral toxicity studies in rats, the no-observed-adverse-effect-level (NOAEL for both S7958 and S6821 was 100 mg/kg bw/day (highest dose tested when administered as a food ad-mix for either 28 or 90 consecutive days, respectively. Furthermore, S6821 demonstrated a lack of maternal toxicity, as well as adverse effects on fetal morphology at the highest dose tested, providing a NOAEL of 1000 mg/kg bw/day for both maternal toxicity and embryo/fetal development when administered orally during gestation to pregnant rats. Keywords: S6821, S7958, FEMA GRAS, Subchronic toxicological evaluation, Genetic toxicological evaluation

  6. Evaluering for læring

    Directory of Open Access Journals (Sweden)

    Bent B. Andresen

    2006-05-01

    Full Text Available

    Første gang publiceret i UNEV nr. 9: Evaluering og feedback i netstøttet uddannelse, sept. 2006, red. Simon Heilesen.
    ISSN 1603-5518.

    I fokus er løbende evalueringer af blended e-læring. Sammen med deres vejledere evaluerer deltagerne typisk deres arbejde med problemstillinger og med at nå mål og tilfredsstille forventninger. Spørgsmålet er, hvordan denne evalueringspraksis bedst kan tilrettelægges. Det er temaet i artiklen. Evalueringer foretages ofte på grundlag af eksamener og samtaler bordet rundt om et e-læringsforløbs samlede værdi. Sigtet er bagudrettet. Artiklen giver et bud på en praksis, som er fremadrettet og mere langsigtet. Især behandles evaluering for læring, som har til formål at skabe passende udfordringer for alle deltagere samt differentiere deres undervisning og vejledning – og dermed øge kvalitet af deres læring. Endvidere behandles spørgsmålet om, hvordan man løbende kan indsamle evalueringsdata og følge op på analyser heraf.

  7. Single-Frequency Nd:YAG Ring Lasers with Corner Cube Prism

    Science.gov (United States)

    Wu, Ke-Ying; Yang, Su-Hui; Zhao, Chang-Ming; Wei, Guang-Hui

    2000-10-01

    We put forward another form of the non-planar ring lasers, in which the corner cube prism is the key element and the Nd:YAG crystal is used as a Porro prism to enclose the ring resonator. The phase shift due to the total internal reflections of the three differently orientated reflection planes of the corner cube prism, Faraday rotation in the Nd:YAG crystal placed in a magnetic field and the different output coupling in S and P polarization form an optical diode and enforce the single-frequency generating power. A round trip analysis of the polarization properties of the resonator is made by the evaluation of Jones matrix.

  8. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-05

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

  9. 3,5-Bis[1-acetyl-5-(4-chlorophenyl-4,5-dihydro-1H-pyrazol-3-yl]-2,6-dimethylpyridine tetrahydrofuran solvate

    Directory of Open Access Journals (Sweden)

    Qun Qian

    2008-07-01

    Full Text Available In the title compound, C29H27Cl2N5O2·C4H8O, the polycyclic system is composed of three parts: one central pyridine ring substituted by two functionalized pyrazoline rings. The dihedral angles between the central pyridine plane and pyrazoline planes are 5.11 (1 and 13.99 (1°, whereas the dihedral angles between each chlorophenyl plane and the attached pyrazoline planes are 88.65 (1 and 83.87 (1°. Molecules are linked by intermolecular C—H...O hydrogen bonds, forming a three-dimensional network.

  10. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

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

  11. From stationary annular rings to rotating Bessel beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2012-04-01

    Full Text Available contributions from the two ring-slits completely overlap (evident in Fig. 1), the angular rotation is non-zero and the entire field at P3 experiences the rotation. 3. EXPERIMENTAL METHODOLOGY The experimental setup used to generate superpositions of higher...) as a ?petal?-field. The field at the ring-slit hologram (i.e., the field at plane P1), we will term the ?singularity?-field and that formed at plane P2 (a distance of 2f from lens L4) will be termed as the ?spiral?-field. 4. RESULTS AND DISCUSSION...

  12. Computing nilpotent quotients in finitely presented Lie rings

    Directory of Open Access Journals (Sweden)

    Csaba Schneider

    1997-12-01

    Full Text Available A nilpotent quotient algorithm for finitely presented Lie rings over Z (and Q is described. The paper studies the graded and non-graded cases separately. The algorithm computes the so-called nilpotent presentation for a finitely presented, nilpotent Lie ring. A nilpotent presentation consists of generators for the abelian group and the products expressed as linear combinations for pairs formed by generators. Using that presentation the word problem is decidable in L. Provided that the Lie ring L is graded, it is possible to determine the canonical presentation for a lower central factor of L. Complexity is studied and it is shown that optimising the presentation is NP-hard. Computational details are provided with examples, timing and some structure theorems obtained from computations. Implementation in C and GAP interface are available.

  13. Semi-algebraic function rings and reflectors of partially ordered rings

    CERN Document Server

    Schwartz, Niels

    1999-01-01

    The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

  14. Plutonium in tree rings from France and Japan

    International Nuclear Information System (INIS)

    Garrec, J.-P.; Suzuki, T.; Mahara, Y.; Santry, D.C.; Miyahara, S.; Sugahara, M.; Zheng, J.; Kudo, A.

    1995-01-01

    Plutonium, along with other radionuclide concentrations, was measured in evergreen tree rings from two different locations. This was used as an information source for the past two centuries. Tree rings are a product of annual layers and thus chronological information is clearly visible. Three trees were harvested in 1988-1990: a French white fir (137 years old) and a spruce tree (177 years old) from the France-Germany border near Nancy, France and a sugi (78 years old) from Nagasaki, Japan. The highest 239 + 240 Pu concentration of 30.0 mBq/kg of dry wood was obtained from the tree rings from Nagasaki, located at the centre of the local fallout of the Pu A-bomb detonated in 1945. This concentration peak was, however, observed in tree rings of 1965-67. The concentration was only 2.9 mBq/kg for the tree rings of 1944-46. The contribution of the local fallout on the surface soils from the A-bomb was 181 mBq/cm 2 at the harvested area of the tree, while the contribution of global fallout by many weapons testing was 5.9 mBq/cm 2 (or 3.3% total fallout in the region). The reason for the over 20 year time lag of 239 + 240 Pu uptake by the tree rings is unknown because many factors influence the routes of Pu into the tree rings. Also the chemical form of Pu in surface soils may have been changed by the surrounding environment. The highest concentration in the tree rings from France was 9.4 mBq/kg which is about 31% of Nagasaki 239 + 240 Pu concentration. (author)

  15. Rotating ring-ring electrode theory and experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  16. NRL ion ring program

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.; Golden, J.; Drobot, A.; Mahaffey, R.A.; Marsh, S.J.; Pasour, J.A.

    1977-01-01

    An experiment is under way to form a storng proton ring using the 200 ka, 1.2 MeV, 50 nsec hollow proton beam recently generated at NRL. The 5 m long magnetic field configuration consists of a magnetic cusp, a compressing magnetic field, a gate field and a magnetic mirror. The midplane value of the magnetic mirror is such that the major radius of the ring will be about 10 cm. The degree of field reversal that will be achieved with 5 x 10 16 protons per pulse from the existing beam depends upon the field reversal is possible with the 600 kA proton beam that would be generated from the low inductance coaxial triode coupled to the upgraded Gamble II generator. The propagation and trapping of an intense proton beam in the experimental magnetic field configuration is investigated numerically. The results show that the self magnetic has a very pronounced effect on the dynamics of the gyrating protons

  17. Opening a spiropyran ring by way of an exciplex intermediate.

    Science.gov (United States)

    Benniston, Andrew C; Harriman, Anthony; Howell, Sarah L; Li, Peiyi; Lydon, Donocadh P

    2007-02-02

    A molecular dyad has been synthesized in which the main chromophore is a 1,4-diethynylated benzene residue terminated with pyrene moieties, this latter unit acting as a single chromophore. A spiropyran group has been condensed to the central phenylene ring so as to position a weak electron donor close to the pyrene unit. Illumination of the pyrene-based chromophore leads to formation of a fluorescent exciplex in polar solvents but pyrene-like fluorescence is observed in nonpolar solvents. The exciplex has a lifetime of a few nanoseconds and undergoes intersystem crossing to the pyrene-like triplet state with low efficiency. Attaching a 4-nitrobenzene group to the open end of the spiropyran unit creates a new route for decay of the exciplex whereby the triplet state of the spiropyran is formed. Nonradiative decay of this latter species results in ring opening to form the corresponding merocyanine species. Rate constants for the various steps have been obtained from time-resolved fluorescence spectroscopy carried out over a modest temperature range. Under visible light illumination, the merocyanine form reverts to the original spiropyran geometry so that the cycle is closed. Energy transfer from the pyrene chromophore to the merocyanine unit leads to an increased rate of ring closure and serves to push the steady-state composition in favor of the spiropyran form.

  18. Topological ring currents in the "empty" ring of benzo-annelated perylenes.

    Science.gov (United States)

    Dickens, Timothy K; Mallion, Roger B

    2011-01-27

    Cyclic conjugation in benzo-annelated perylenes is examined by means of the topological π-electron ring currents calculated for each of their constituent rings, in a study that is an exact analogy of a recent investigation by Gutman et al. based on energy-effect values for the corresponding rings in each of these structures. "Classical" approaches, such as Kekulé structures, Clar "sextet" formulas, and circuits of conjugation, predict that the central ring in perylene is "empty" and thus contributes negligibly to cyclic conjugation. However, conclusions from the present calculations of topological ring currents agree remarkably with those arising from the earlier study involving energy-effect values in that, contrary to what would be predicted from the classical approaches, rings annelated in an angular fashion relative to the central ring of these perylene structures materially increase the extent of that ring's involvement in cyclic conjugation. It is suggested that such close quantitative agreement between the predictions of these two superficially very different indices (energy effect and topological ring current) might be due to the fact that, ultimately, both depend, albeit in ostensibly quite different ways, only on an adjacency matrix that contains information about the carbon-carbon connectivity of the conjugated system in question.

  19. Ring rolling process simulation for geometry optimization

    Science.gov (United States)

    Franchi, Rodolfo; Del Prete, Antonio; Donatiello, Iolanda; Calabrese, Maurizio

    2017-10-01

    Ring Rolling is a complex hot forming process where different rolls are involved in the production of seamless rings. Since each roll must be independently controlled, different speed laws must be set; usually, in the industrial environment, a milling curve is introduced to monitor the shape of the workpiece during the deformation in order to ensure the correct ring production. In the present paper a ring rolling process has been studied and optimized in order to obtain anular components to be used in aerospace applications. In particular, the influence of process input parameters (feed rate of the mandrel and angular speed of main roll) on geometrical features of the final ring has been evaluated. For this purpose, a three-dimensional finite element model for HRR (Hot Ring Rolling) has been implemented in SFTC DEFORM V11. The FEM model has been used to formulate a proper optimization problem. The optimization procedure has been implemented in the commercial software DS ISight in order to find the combination of process parameters which allows to minimize the percentage error of each obtained dimension with respect to its nominal value. The software allows to find the relationship between input and output parameters applying Response Surface Methodology (RSM), by using the exact values of output parameters in the control points of the design space explored through FEM simulation. Once this relationship is known, the values of the output parameters can be calculated for each combination of the input parameters. After the calculation of the response surfaces for the selected output parameters, an optimization procedure based on Genetic Algorithms has been applied. At the end, the error between each obtained dimension and its nominal value has been minimized. The constraints imposed were the maximum values of standard deviations of the dimensions obtained for the final ring.

  20. Ring distributions leading to species formation: a global topographic analysis of geographic barriers associated with ring species

    Directory of Open Access Journals (Sweden)

    Monahan William B

    2012-03-01

    Full Text Available Abstract Background In the mid 20th century, Ernst Mayr and Theodosius Dobzhansky championed the significance of circular overlaps or ring species as the perfect demonstration of speciation, yet in the over 50 years since, only a handful of such taxa are known. We developed a topographic model to evaluate whether the geographic barriers that favor processes leading to ring species are common or rare, and to predict where other candidate ring barriers might be found. Results Of the 952,147 geographic barriers identified on the planet, only about 1% are topographically similar to barriers associated with known ring taxa, with most of the likely candidates occurring in under-studied parts of the world (for example, marine environments, tropical latitudes. Predicted barriers separate into two distinct categories: (i single cohesive barriers (2, associated with taxa that differentiate at smaller spatial scales (salamander: Ensatina eschscholtzii; tree: Acacia karroo; and (ii composite barriers - formed by groups of barriers (each 184,000 to 1.7 million km2 in close geographic proximity (totaling 1.9 to 2.3 million km2 - associated with taxa that differentiate at larger spatial scales (birds: Phylloscopus trochiloides and Larus (sp. argentatus and fuscus. When evaluated globally, we find a large number of cohesive barriers that are topographically similar to those associated with known ring taxa. Yet, compared to cohesive barriers, an order of magnitude fewer composite barriers are similar to those that favor ring divergence in species with higher dispersal. Conclusions While these findings confirm that the topographic conditions that favor evolutionary processes leading to ring speciation are, in fact, rare, they also suggest that many understudied natural systems could provide valuable demonstrations of continuous divergence towards the formation of new species. Distinct advantages of the model are that it (i requires no a priori information on the

  1. Kayser-Fleischer Rings

    Science.gov (United States)

    ... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

  2. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

    A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

  3. TIMING OF FALSE RING FORMATION IN PINUS HALEPENSIS AND ARBUTUS UNEDO IN SOUTHERN ITALY: OUTLOOK FROM AN ANALYSIS OF XYLOGENESIS AND TREE-RING CHRONOLOGIES

    Directory of Open Access Journals (Sweden)

    Veronica eDe Micco

    2016-05-01

    Full Text Available Mediterranean tree rings are characterized by Intra-Annual Density Fluctuations (IADFs due to partly climate-driven cambial activity. IADFs are used as structural signals to gain information on relations between environmental conditions and eco-physiological processes during xylogenesis, with intra-annual resolution.To reach an unbiased synchronization of the IADF position within tree rings and seasonal fluctuations in environmental conditions, it is necessary to know the timing of cambial activity and wood formation, which are species- and site-specific processes.We applied the microcoring technique to analyze xylogenesis in Pinus halepensis and Arbutus unedo. To the best of our knowledge, this is the first attempt to study xylogenesis in a hardwood species forming frequent IADFs. Both species co-occur at a site in southern Italy characterized by a Mediterranean climate. To facilitate tree-ring dating and identification of IADFs, we performed traditional dendroecological analysis. We analyzed xylogenesis during summer, which is considered a constraint for xylogenesis and a trigger for IADF formation. We followed the different phases of cell development in the current wood increment with the aim of evaluating whether and which type of IADFs were formed. We additionally analyzed the same phases again in September and in winter to verify the possible formation of IADFs in fall and whether cell production and differentiation was completed by the end of the calendar year.Both species formed the same type of IADFs (earlywood-like cells within latewood, due to temporary growth restoration triggered by rain events during the period of summer drought. At the end of the calendar year, no cells in the phases of enlargement and secondary cell wall deposition occurred. A. unedo was more sensitive than P. halepensis because IADFs were formed earlier in the season and were more frequent in the tree-ring series.The dendro-anatomical approach, combining

  4. Timing of False Ring Formation in Pinus halepensis and Arbutus unedo in Southern Italy: Outlook from an Analysis of Xylogenesis and Tree-Ring Chronologies.

    Science.gov (United States)

    De Micco, Veronica; Balzano, Angela; Čufar, Katarina; Aronne, Giovanna; Gričar, Jožica; Merela, Maks; Battipaglia, Giovanna

    2016-01-01

    Mediterranean tree rings are characterized by intra-annual density fluctuations (IADFs) due to partly climate-driven cambial activity. IADFs are used as structural signals to gain information on relations between environmental conditions and eco-physiological processes during xylogenesis, with intra-annual resolution. To reach an unbiased synchronization of the IADF position within tree rings and seasonal fluctuations in environmental conditions, it is necessary to know the timing of cambial activity and wood formation, which are species- and site-specific processes. We applied the microcoring technique to analyze xylogenesis in Pinus halepensis and Arbutus unedo. To the best of our knowledge, this is the first attempt to study xylogenesis in a hardwood species forming frequent IADFs. Both species co-occur at a site in southern Italy characterized by a Mediterranean climate. To facilitate tree-ring dating and identification of IADFs, we performed traditional dendroecological analysis. We analyzed xylogenesis during summer, which is considered a constraint for xylogenesis and a trigger for IADF formation. We followed the different phases of cell development in the current wood increment with the aim of evaluating whether and which type of IADFs were formed. We additionally analyzed the same phases again in September and in winter to verify the possible formation of IADFs in fall and whether cell production and differentiation was completed by the end of the calendar year. Both species formed the same type of IADFs (earlywood-like cells within latewood), due to temporary growth restoration triggered by rain events during the period of summer drought. At the end of the calendar year, no cells in the phases of enlargement and secondary cell wall deposition occurred. A. unedo was more sensitive than P. halepensis because IADFs were formed earlier in the season and were more frequent in the tree-ring series. The dendro-anatomical approach, combining analysis of tree-ring

  5. Determining the annual periodicity of growth rings in seven tree species of a tropical moist forest in Santa Cruz, Bolivia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, L.; Villalba, R.; Pena-Claros, M.

    2012-07-01

    To determine the annual periodicity of growth rings in seven tree species from a tropical moist forest in Santa Cruz, Bolivia, a fire scar was used as a marker point to verify the annual nature of tree rings. The number of tree rings formed between the 1995 fire scar and the collection of the cross sections in 2002 was visually identified. The seven species showed annual growth rings. In most cases, boundaries between rings were marked by the presence of marginal parenchyma and wall-thick ed fibers formed at the end of the growing season. Growth lenses and false rings were recorded in some species. Tree rings can be carefully used in Santa Cruz forests to determine rates of growth. This information is crucial for defining forest management practices in tropical regions. (Author) 21 refs.

  6. Complexation of Cm(III) and Eu(III) with 2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine and 2-bromohexanoic acid studied by time-resolved laser fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Bremer, A.; Panak, P.J.; Heidelberg Univ.; Geist, A.

    2013-01-01

    The complexation of Cm(III) and Eu(III) with 2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine (C5-BPP) and 2-bromohexanoic acid as lipophilic anion has been investigated by time-resolved laser fluorescence spectroscopy. Upon increasing ligand concentration three different Cm(III)-C5-BPP species with emission bands at 604.1 nm, 607.9 nm and 611.4 nm, respectively, are found and attributed to complexes with one, two and three C5-BPP molecules in the inner coordination sphere. Comparison with results of TRLFS experiments without 2-bromohexanoic acid shows that the C5-BPP ligand is able to completely displace the lipophilic anion from the inner coordination sphere, forming [Cm(C5-BPP) 3 ] 3+ complexes. This complex is also found in the organic phase of an extraction experiment performed with Cm(III), demonstrating that the lipophilic anion required for the extraction is not directly coordinated to the metal ion in the species formed during extraction. In case of Eu(III) the number of different species formed cannot be determined accurately. Nevertheless, the formation of the complex [EU(C5-BPP) 3 ] 3+ in the presence of 2-bromohexanoic acid is confirmed. (orig.)

  7. 1-[5-(2-Chlorophenyl-3-(4-methylphenyl-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one

    Directory of Open Access Journals (Sweden)

    Farook Adam

    2016-01-01

    Full Text Available The title compound, C18H17ClN2O, crystallized with two independent molecules (the S and R enantiomers in the asymmetric unit. The molecules are V-shaped with the two aromatic rings inclined to one another by 78.78 (11 and 81.23 (11°. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming chains along the c-axis direction. The chains are linked via C—H...π interactions, forming a three-dimensional framework. The crystal structure was refined as a two-component twin.

  8. Structure-based design synthesis of functionalized 3-(5-(s-phenyl)-4H-pyrazol-3-yl)-2H-chromen-2-one motifs and indigenous plant extracts and their antimalarial potential

    Science.gov (United States)

    Olayinka, Ajani; Grace, Olasehinde; Titilope, Dokunmu; Ruth, Diji-Geske; Olabode, Onileere; John, Openibo; Oreoluwa, Oluseye; Tochukwu, Chileke; Ezekiel, Adebiyi

    2018-04-01

    Resistance of the malaria parasite to conventional therapeutic agents calls for increased efforts in antimalarial drug discovery. Current efforts should be targeted at developing safe and affordable new agents to counter the spread of malaria parasites that are resistant to existing therapy. In this study, toxicological and in vivo antiplasmodial properties of 3-(5-(s-phenyl)-4H-pyrazol-3-yl)-42H-chromen-2, Mangifera indica and Tithonia diversifolia in swiss albino mice models, Musmusculus were investigated. 2H-Chromen-2-one also known as coumarin is highly privileged oxygen-containing heterocyclic entity which are present in plant kingdom as secondary metabolites. The maceration technique of crude drug extraction was employed using cold water extraction. Toxicological analysis was carried out using Lorke's method for acute toxicity testing while the chemosuppressive activity was carried out using Peter's four day test on early infection. We also report the synthesis of functionalized 3-(5-(s-phenyl)-4H-pyrazol-3-yl)-2H-chromen-2-one motifs via microwave assisted synthetic approach and isolation of indigenous plant extract in order to investigate their antimalarial efficacy. The condensation reaction of 3-acetylcoumarin with various benzaldehyde derivatives resulted in the formation of 3-[3-acryloyl]-2H-chromen-2-one which was subsequently reaction the hydrazine hydrate via microwave assisted hydrazinolysis to afford the targeted 3-(5-(s-phenyl)-4H-pyrazol-3-yl)-2H-chromen-2-one motifs. The chemical structures were confirmed by analytical data and spectroscopic means such as FT-IR, UV, 1H NMR, 13C NMR and DEPT-135. The microwave assisted reaction was remarkably successful and gave targeted 3-(5-(s-phenyl)-4H-pyrazol-3-yl)-2H-chromen-2-one motifs in higher yields at lesser reaction time compared to conventional heating method. The LD50 of the aqueous extracts of the leaves and stem bark Mangifera indica was established to be ± 707.11 mg/kg b.w., p.o. (body weight

  9. Assembly of the MreB-associated cytoskeletal ring of Escherichia coli.

    Science.gov (United States)

    Vats, Purva; Shih, Yu-Ling; Rothfield, Lawrence

    2009-04-01

    The Escherichia coli actin homologue MreB is part of a helical cytoskeletal structure that winds around the cell between the two poles. It has been shown that MreB redistributes during the cell cycle to form circumferential ring structures that flank the cytokinetic FtsZ ring and appear to be associated with division and segregation of the helical cytoskeleton. We show here that the MreB cytoskeletal ring also contains the MreC, MreD, Pbp2 and RodA proteins. Assembly of MreB, MreC, MreD and Pbp2 into the ring structure required the FtsZ ring but no other known components of the cell division machinery, whereas assembly of RodA into the cytoskeletal ring required one or more additional septasomal components. Strikingly, MreB, MreC, MreD and RodA were each able to independently assemble into the cytoskeletal ring and coiled cytoskeletal structures in the absence of any of the other ring components. This excludes the possibility that one or more of these proteins acts as a scaffold for incorporation of the other proteins into these structures. In contrast, incorporation of Pbp2 required the presence of MreC, which may provide a docking site for Pbp2 entry.

  10. Formation of moon induced gaps in dense planetary rings

    Science.gov (United States)

    Grätz, F.; Seiß, M.; Spahn, F.

    2017-09-01

    Recent works have shown that bodies embedded in planetary rings create S-shaped density modula- tions called propellers if their mass deceeds a certain threshold or cause a gap around the entire circumference of the disc if the embedded bodies mass exceeds it. Two counteracting physical processes govern the dynamics and determine what structure is created: The gravitational disturber excerts a torque on nearby disc particles, sweeping them away from itself on both sides thus depleting the discs density and forming a gap. Diffusive spreading of the disc material due to collisions counteracts the gravitational scattering and has the tendency to fill the gap. We develop a nonlinear diffusion model that accounts for those two counteracting processes and describes the azimutally averaged surface density profile an embedded moon creates in planetary rings. The gaps width depends on the moons mass, its radial position and the rings viscosity allowing us to estimate the rings viscosity in the vicinity of the Encke and Keeler gap in Saturns A-Ring and compare it to previous measurements. We show that for the Keeler gap the time derivative of the semi-major axis as derived by Goldreich and Tremaine 1980 is underestimated yielding an underestimated viscosity for the ring. We therefore derive a corrected expression for said time derivative by fitting the solutions of Hill's equations for an ensemble of test particles. Furthermore we estimate the masses for potentionally unseen moonlets in the C-Ring and Cassini division.

  11. Vortex ring behavior provides the epigenetic blueprint for the human heart.

    Science.gov (United States)

    Arvidsson, Per M; Kovács, Sándor J; Töger, Johannes; Borgquist, Rasmus; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

    2016-02-26

    The laws of fluid dynamics govern vortex ring formation and precede cardiac development by billions of years, suggesting that diastolic vortex ring formation is instrumental in defining the shape of the heart. Using novel and validated magnetic resonance imaging measurements, we show that the healthy left ventricle moves in tandem with the expanding vortex ring, indicating that cardiac form and function is epigenetically optimized to accommodate vortex ring formation for volume pumping. Healthy hearts demonstrate a strong coupling between vortex and cardiac volumes (R(2) = 0.83), but this optimized phenotype is lost in heart failure, suggesting restoration of normal vortex ring dynamics as a new, and possibly important consideration for individualized heart failure treatment. Vortex ring volume was unrelated to early rapid filling (E-wave) velocity in patients and controls. Characteristics of vortex-wall interaction provide unique physiologic and mechanistic information about cardiac diastolic function that may be applied to guide the design and implantation of prosthetic valves, and have potential clinical utility as therapeutic targets for tailored medicine or measures of cardiac health.

  12. Conceptual design of a moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1983-01-01

    A design of a prototype Moving-Ring Reactor has been completed. The fusion fuel is confined in current-carrying rings of magnetically field-reversed plasma (''compact toroids''). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three ''burn stations''. Separator coils and a slight axial guide-field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for one third of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power. The first wall and tritium breeding blanket designs make credible use of helium cooling, SiC and Li 2 O to minimize structural radioactivity. ''Hands-on'' maintenance is possible on all reactor components outside the blanket. The first wall and blanket are designed to shut the reactor down passively in the event of a loss-of-coolant or loss-of-flow accident. Helium removes heat from the first wall, blanket and shield, and is used in a closed-cycle gas turbine to produce electricity. Energy residing in the plasma ring at the end of the burn is recovered via magnetic expansion. Electrostatic direct conversion is not used in this design. The reactor produces a constant net power of 99 MW(e). (author)

  13. In silico predictions of LH2 ring sizes from the crystal structure of a single subunit using molecular dynamics simulations.

    Science.gov (United States)

    Janosi, Lorant; Keer, Harindar; Cogdell, Richard J; Ritz, Thorsten; Kosztin, Ioan

    2011-07-01

    Most of the currently known light-harvesting complexes 2 (LH2) rings are formed by 8 or 9 subunits. As of now, questions like "what factors govern the LH2 ring size?" and "are there other ring sizes possible?" remain largely unanswered. Here, we investigate by means of molecular dynamics (MD) simulations and stochastic modeling the possibility of predicting the size of an LH2 ring from the sole knowledge of the high resolution crystal structure of a single subunit. Starting with single subunits of two LH2 rings with known size, that is, an 8-ring from Rs. moliscianum (MOLI) and a 9-ring from Rps. acidophila (ACI), and one with unknown size (referred to as X), we build atomic models of subunit dimers corresponding to assumed 8-, 9-, and 10-ring geometries. After inserting each of the dimers into a lipid-water environment, we determine the preferred angle between the corresponding subunits by three methods: (1) energy minimization, (2) free MD simulations, and (3) potential of mean force calculations. We find that the results from all three methods are consistent with each other, and when taken together, it allows one to predict with reasonable level of confidence the sizes of the corresponding ring structures. One finds that X and ACI very likely form a 9-ring, while MOLI is more likely to form an 8-ring than a 9-ring. Finally, we discuss both the merits and limitations of all three prediction methods. Copyright © 2011 Wiley-Liss, Inc.

  14. Undervisning og læring i STEM

    DEFF Research Database (Denmark)

    Nielsen, Jan Alexis; Waaddegaard, Nina Holst; Dolin, Jens

    2017-01-01

    Dette afsnit handler om reviewspørgsmål 1: Hvilke indsatser, metoder og strategier kan ifølge eksisterende forskning styrke undervisningen med henblik på elevers læring – i form af tilegnelse af viden, færdigheder, kompetencer og naturvidenskabelig almendannelse – herunder underviseres brug af en...

  15. Process for producing curved surface of membrane rings for large containers, particulary for prestressed concrete pressure vessels of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1977-01-01

    Membrane rings for large pressure vessels, particularly for prestressed-concrete pressure vessels, often have curved surfaces. The invention describes a process of producing these at site, which is particularly advantageous as the forming and installation of the vessel component coincide. According to the invention, the originally flat membrane ring is set in a predetermined position, is then pressed in sections by a forming tool (with a preformed support ring as opposite tool), and shaped. After this, the shaped parts are welded to the ring-shaped wall parts of the large vessel. The manufacture of single and double membrane rings arrangements is described. (HP) [de

  16. Conference on Commutative rings, integer-valued polynomials and polynomial functions

    CERN Document Server

    Frisch, Sophie; Glaz, Sarah; Commutative Algebra : Recent Advances in Commutative Rings, Integer-Valued Polynomials, and Polynomial Functions

    2014-01-01

    This volume presents a multi-dimensional collection of articles highlighting recent developments in commutative algebra. It also includes an extensive bibliography and lists a substantial number of open problems that point to future directions of research in the represented subfields. The contributions cover areas in commutative algebra that have flourished in the last few decades and are not yet well represented in book form. Highlighted topics and research methods include Noetherian and non- Noetherian ring theory as well as integer-valued polynomials and functions. Specific topics include: ·    Homological dimensions of Prüfer-like rings ·    Quasi complete rings ·    Total graphs of rings ·    Properties of prime ideals over various rings ·    Bases for integer-valued polynomials ·    Boolean subrings ·    The portable property of domains ·    Probabilistic topics in Intn(D) ·    Closure operations in Zariski-Riemann spaces of valuation domains ·    Stability of do...

  17. Completeness of the ring of polynomials

    DEFF Research Database (Denmark)

    Thorup, Anders

    2015-01-01

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

  18. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

    Science.gov (United States)

    Durgun, E; Grossman, Jeffrey C

    2013-03-21

    Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

  19. Ring faults and ring dikes around the Orientale basin on the Moon.

    Science.gov (United States)

    Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T

    2018-08-01

    The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

  20. Optical control of spin-dependent thermal transport in a quantum ring

    Science.gov (United States)

    Abdullah, Nzar Rauf

    2018-05-01

    We report on calculation of spin-dependent thermal transport through a quantum ring with the Rashba spin-orbit interaction. The quantum ring is connected to two electron reservoirs with different temperatures. Tuning the Rashba coupling constant, degenerate energy states are formed leading to a suppression of the heat and thermoelectric currents. In addition, the quantum ring is coupled to a photon cavity with a single photon mode and linearly polarized photon field. In a resonance regime, when the photon energy is approximately equal to the energy spacing between two lowest degenerate states of the ring, the polarized photon field can significantly control the heat and thermoelectric currents in the system. The roles of the number of photon initially in the cavity, and electron-photon coupling strength on spin-dependent heat and thermoelectric currents are presented.

  1. Cell culture arrays using micron-sized ferromagnetic ring-shaped thin films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chen-Yu; Wei, Zung-Hang, E-mail: wei@pme.nthu.edu.tw [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu City 300, Taiwan (China); Lai, Mei-Feng; Ger, Tzong-Rong [Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu City 300, Taiwan (China)

    2015-05-07

    Cell patterning has become an important technology for tissue engineering. In this research, domain walls are formed at the two ends of a ferromagnetic ring thin film after applying a strong external magnetic field, which can effectively attract magnetically labeled cells and control the position for biological cell. Magnetophoresis experiment was conducted to quantify the magnetic nanoparticle inside the cells. A ring-shaped magnetic thin films array was fabricated through photolithography. It is observed that magnetically labeled cells can be successfully attracted to the two ends of the ring-shaped magnetic thin film structure and more cells were attracted and further attached to the structures. The cells are co-cultured with the structure and kept proliferating; therefore, such ring thin film can be an important candidate for in-vitro biomedical chips or tissue engineering.

  2. Cell culture arrays using micron-sized ferromagnetic ring-shaped thin films

    International Nuclear Information System (INIS)

    Huang, Chen-Yu; Wei, Zung-Hang; Lai, Mei-Feng; Ger, Tzong-Rong

    2015-01-01

    Cell patterning has become an important technology for tissue engineering. In this research, domain walls are formed at the two ends of a ferromagnetic ring thin film after applying a strong external magnetic field, which can effectively attract magnetically labeled cells and control the position for biological cell. Magnetophoresis experiment was conducted to quantify the magnetic nanoparticle inside the cells. A ring-shaped magnetic thin films array was fabricated through photolithography. It is observed that magnetically labeled cells can be successfully attracted to the two ends of the ring-shaped magnetic thin film structure and more cells were attracted and further attached to the structures. The cells are co-cultured with the structure and kept proliferating; therefore, such ring thin film can be an important candidate for in-vitro biomedical chips or tissue engineering

  3. Potentiometric study of complexes formed between (s)-&alpha

    African Journals Online (AJOL)

    isoxazole ring. The first complex [CuHL], which is fully formed by pH 4 is proposed to be with {N,O} bonding which results in the formation of a stable five membered chelate ring. The [CuL] species has some enhanced stability which suggest ...

  4. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  5. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  6. Boundary rings and N=2 coset models

    International Nuclear Information System (INIS)

    Lerche, W.; Walcher, J.

    2002-01-01

    We investigate boundary states of N=2 coset models based on Grassmannians Gr(n,n+k), and find that the underlying intersection geometry is given by the fusion ring of U(n). This is isomorphic to the quantum cohomology ring of Gr(n,n+k+1), which in turn can be encoded in a 'boundary' superpotential whose critical points correspond to the boundary states. In this way the intersection properties can be represented in terms of a soliton graph that forms a generalized, Z n+k+1 symmetric McKay quiver. We investigate the spectrum of bound states and find that the rational boundary CFT produces only a small subset of the possible quiver representations

  7. The Rotating Ring-Ring Electrode. Theory and Experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  8. Transformation of self-assembled InAs/InP quantum dots into quantum rings without capping.

    Science.gov (United States)

    Sormunen, Jaakko; Riikonen, Juha; Mattila, Marco; Tiilikainen, Jouni; Sopanen, Markku; Lipsanen, Harri

    2005-08-01

    Transformation of self-assembled InAs quantum dots (QDs) on InP(100) into quantum rings (QRs) is studied. In contrast to the typical approach to III--V semiconductor QR growth, the QDs are not capped to form rings. Atomic force micrographs reveal a drastic change from InAs QDs into rings after a growth interruption in tertiarybutylphosphine ambient. Strain energy relief in the InAs QD is discussed and a mechanism for dot-to-ring transformation by As/P exchange reactions is proposed.

  9. Instrumental neutron activation analysis of tree rings for dendrochemical studies

    International Nuclear Information System (INIS)

    Schaumloffel, J.C.; Filby, R.H.

    1996-01-01

    Instrumental neutron activation analysis (INAA) was employed to determine zinc, cadmium and potassium concentrations in the growth rings of ponderosa pine (Pinus ponderosa Dougl.) trees growing along the shores of Lake Roosevelt in Washington State, U.S.A. where mineral processing activities have resulted in high burdens of zinc and cadmium in the lake sediments. The tree growing along the contaminated waterway display elevated concentrations of zinc in its growth rings relative to a tree growing along an uncontaminated tributary of Lake Roosevelt. Cadmium concentrations in the growth rings from both sites are similar from 1988 to 1993. Water quality data indicate an increased concentration of cadmium in the lake from 1984 to 1988. The increased concentrations of cadmium in the lake water were reflected in apparent increases in concentrations of cadmium in individual rings of the tree sampled at the contaminated site. This suggests that translocation of cadmium in the sapwood of heartwood-forming species does not occur in the short term, and thus may not be a limiting factor in using trees as environmental monitors for cadmium. In addition, five-year tree ring segments were analyzed and subsequently reanalyzed as individual single-year ring segments. The analytical data obtained for the pooled individual rings are essentially the same as for the five-year segments, demonstrating the utility of NAA for dendrochemical studies. (author). 24 refs., 5 figs., 2 tabs

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

    Science.gov (United States)

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

    2017-05-01

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

  11. Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

    Directory of Open Access Journals (Sweden)

    P. Ilanthirayan

    2017-12-01

    Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.

  12. Non-Linear Dynamics of Saturn's Rings

    Science.gov (United States)

    Esposito, L. W.

    2016-12-01

    Non-linear processes can explain why Saturn's rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. Stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, that push the system across thresholds that lead to persistent states. Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit, with relative velocity ranging from nearly zero to a multiple of the orbit average. Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like `straw' that can explain the halo morphology and spectroscopy: Cyclic velocity changes cause perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; surrounding particles diffuse back too slowly to erase the effect: this gives the halo morphology; this requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping explains both small and large particles at resonances. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating it as an asymmetric random walk with reflecting boundaries

  13. PREFACE: Special section on vortex rings Special section on vortex rings

    Science.gov (United States)

    Fukumoto, Yasuhide

    2009-10-01

    This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

  14. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

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

  15. FUZZY RINGS AND ITS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Karyati Karyati

    2017-01-01

      One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

  16. A stereoselective synthesis of (+)-physoperuvine using a tandem aza-Claisen rearrangement and ring closing metathesis reaction.

    Science.gov (United States)

    Zaed, Ahmed M; Swift, Michael D; Sutherland, Andrew

    2009-07-07

    A stereoselective synthesis of (+)-physoperuvine, a tropane alkaloid from Physalis peruviana Linne has been developed using a one-pot tandem aza-Claisen rearrangement and ring closing metathesis reaction to form the key amino-substituted cycloheptene ring.

  17. On the propagation and decay of North Brazil Current rings

    Science.gov (United States)

    Jochumsen, Kerstin; Rhein, Monika; Hüttl-Kabus, Sabine; BöNing, Claus W.

    2010-10-01

    Near the western boundary of the tropical North Atlantic, where the North Brazil Current (NBC) retroflects into the North Equatorial Countercurrent, large anticyclonic rings are shed. After separating from the retroflection region, the so-called NBC rings travel northwestward along the Brazilian coast, until they reach the island chain of the Lesser Antilles and disintegrate. These rings contribute substantially to the upper limb return flow of the Atlantic Meridional Overturning Circulation by carrying South Atlantic Water into the northern subtropical gyre. Their relevance for the northward transport of South Atlantic Water depends on the frequency of their generation as well as on their horizontal and vertical structure. The ring shedding and propagation and the complex interaction of the rings with the Lesser Antilles are investigated in the ? Family of Linked Atlantic Model Experiments (FLAME) model. The ring properties simulated in FLAME reach the upper limit of the observed rings in diameter and agree with recent observations on seasonal variability, which indicates a maximum shedding during the first half of the year. When the rings reach the shallow topography of the Lesser Antilles, they are trapped by the island triangle of St. Lucia, Barbados and Tobago and interact with the island chain. The model provides a resolution that is capable of resolving the complex topographic conditions at the islands and illuminates various possible fates for the water contained in the rings. It also reproduces laboratory experiments that indicate that both cyclones and anticyclones are formed after a ring passes through a topographic gap. Trajectories of artificial floats, which were inserted into the modeled velocity field, are used to investigate the pathways of the ring cores and their fate after they encounter the Lesser Antilles. The majority of the floats entered the Caribbean, while the northward Atlantic pathway was found to be of minor importance. No prominent

  18. Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators

    International Nuclear Information System (INIS)

    Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang

    2015-01-01

    A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)

  19. From ring-in-ring to sphere-in-sphere: self-assembly of discrete 2D and 3D architectures with increasing stability.

    Science.gov (United States)

    Sun, Bin; Wang, Ming; Lou, Zhichao; Huang, Mingjun; Xu, Chenglong; Li, Xiaohong; Chen, Li-Jun; Yu, Yihua; Davis, Grant L; Xu, Bingqian; Yang, Hai-Bo; Li, Xiaopeng

    2015-02-04

    Directed by increasing the density of coordination sites (DOCS) to increase the stability of assemblies, discrete 2D ring-in-rings and 3D sphere-in-sphere were designed and self-assembled by one tetratopic pyridyl-based ligand with 180° diplatinum(II) acceptors and naked Pd(II), respectively. The high DOCS resulted by multitopic ligand provided more geometric constraints to form discrete structures with high stability. Compared to reported supramolecular hexagons and polyhedra by ditotpic ligands, the self-assembly of such giant architectures using multitopic ligands with all rigid backbone emphasized the structural integrity with precise preorganization of entire architecture, and required elaborate synthetic operations for ligand preparation. In-depth structural characterization was conducted to support desired structures, including multinuclear NMR ((1)H, (31)P, and (13)C) analysis, 2D NMR spectroscopy (COSY and NOESY), diffusion-ordered NMR spectroscopy (DOSY), multidimensional mass spectrometry, TEM and AFM. Furthermore, a quantitative definition of DOCS was proposed to compare 2D and 3D structures and correlate the DOCS and stability of assemblies in a quantitative manner. Finally, ring-in-rings in DMSO or DMF could undergo hierarchical self-assembly into the ordered nanostructures and generated translucent supramolecular metallogels.

  20. Non-Linear Dynamics of Saturn’s Rings

    Science.gov (United States)

    Esposito, Larry W.

    2015-11-01

    Non-linear processes can explain why Saturn’s rings are so active and dynamic. Ring systems differ from simple linear systems in two significant ways: 1. They are systems of granular material: where particle-to-particle collisions dominate; thus a kinetic, not a fluid description needed. We find that stresses are strikingly inhomogeneous and fluctuations are large compared to equilibrium. 2. They are strongly forced by resonances: which drive a non-linear response, pushing the system across thresholds that lead to persistent states.Some of this non-linearity is captured in a simple Predator-Prey Model: Periodic forcing from the moon causes streamline crowding; This damps the relative velocity, and allows aggregates to grow. About a quarter phase later, the aggregates stir the system to higher relative velocity and the limit cycle repeats each orbit.Summary of Halo Results: A predator-prey model for ring dynamics produces transient structures like ‘straw’ that can explain the halo structure and spectroscopy: This requires energetic collisions (v ≈ 10m/sec, with throw distances about 200km, implying objects of scale R ≈ 20km).Transform to Duffing Eqn : With the coordinate transformation, z = M2/3, the Predator-Prey equations can be combined to form a single second-order differential equation with harmonic resonance forcing.Ring dynamics and history implications: Moon-triggered clumping at perturbed regions in Saturn’s rings creates both high velocity dispersion and large aggregates at these distances, explaining both small and large particles observed there. We calculate the stationary size distribution using a cell-to-cell mapping procedure that converts the phase-plane trajectories to a Markov chain. Approximating the Markov chain as an asymmetric random walk with reflecting boundaries allows us to determine the power law index from results of numerical simulations in the tidal environment surrounding Saturn. Aggregates can explain many dynamic aspects

  1. Assembly of silver nanowire ring induced by liquid droplet

    Science.gov (United States)

    Seong, Baekhoon; Park, Hyun Sung; Chae, Ilkyeong; Lee, Hyungdong; Wang, Xiaofeng; Jang, Hyung-Seok; Jung, Jaehyuck; Lee, Changgu; Lin, Liwei; Byun, Doyoung

    2017-11-01

    Several forces in the liquid droplet drive the nanomaterials to naturally form an assembled structure. During evaporation of a liquid droplet, nanomaterials can move to the rim of the droplet by convective flow and capillary flow, due to the difference in temperature between the top and contact line of the droplet. Here, we demonstrate a new, simple and scalable technology for the fabrication of ring-shaped Ag NWs by a spraying method. We experimentally identify the compressive force of the droplet driven by surface tension as the key mechanism for the self-assembly of ring structures. We investigated the progress of ring shape formation of Ag NWs according to the droplet size with theoretically calculated optimal conditions. As such, this self-assembly technique of making ring-shaped structures from Ag NWs could be applied to other nanomaterials. This work was supported by the New & Renewable Energy R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korea government Ministry of Trade, Industry and Energy. (No. 20163010071630).

  2. Tandem radical reactions and ring-closing metathesis. Application in the synthesis of cyclooctenes.

    Science.gov (United States)

    Sibi, Mukund P; Aasmul, Mona; Hasegawa, Hikaru; Subramanian, Thangaiah

    2003-08-07

    [reaction: see text] Fumarate- and acrylate-substituted oxazolidinones undergo tandem radical reaction to form dienes in moderate to good yields. The resulting dienes provide cyclooctenes in moderate to good yields after ring-closing metathesis (RCM). The role of the carbon backbone substituents and other variables in the efficiency of the eight-membered ring formation is discussed.

  3. Storm-time ring current: model-dependent results

    Directory of Open Access Journals (Sweden)

    N. Yu. Ganushkina

    2012-01-01

    Full Text Available The main point of the paper is to investigate how much the modeled ring current depends on the representations of magnetic and electric fields and boundary conditions used in simulations. Two storm events, one moderate (SymH minimum of −120 nT on 6–7 November 1997 and one intense (SymH minimum of −230 nT on 21–22 October 1999, are modeled. A rather simple ring current model is employed, namely, the Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM, in order to make the results most evident. Four different magnetic field and two electric field representations and four boundary conditions are used. We find that different combinations of the magnetic and electric field configurations and boundary conditions result in very different modeled ring current, and, therefore, the physical conclusions based on simulation results can differ significantly. A time-dependent boundary outside of 6.6 RE gives a possibility to take into account the particles in the transition region (between dipole and stretched field lines forming partial ring current and near-Earth tail current in that region. Calculating the model SymH* by Biot-Savart's law instead of the widely used Dessler-Parker-Sckopke (DPS relation gives larger and more realistic values, since the currents are calculated in the regions with nondipolar magnetic field. Therefore, the boundary location and the method of SymH* calculation are of key importance for ring current data-model comparisons to be correctly interpreted.

  4. Effect of the Mitral Valve's Anterior Leaflet on Axisymmetry of Transmitral Vortex Ring.

    Science.gov (United States)

    Falahatpisheh, Ahmad; Pahlevan, Niema M; Kheradvar, Arash

    2015-10-01

    The shape and formation of transmitral vortex ring are shown to be associated with diastolic function of the left ventricle (LV). Transmitral vortex ring is a flow feature that is observed to be non-axisymmetric in a healthy heart and its inherent asymmetry in the LV assists in efficient ejection of the blood during systole. This study is a first step towards understanding the effects of the mitral valve's anterior leaflet on transmitral flow. We experimentally study a single-leaflet model of the mitral valve to investigate the effect of the anterior leaflet on the axisymmetry of the generated vortex ring based on the three-dimensional data acquired using defocusing digital particle image velocimetry. Vortex rings form downstream of a D-shaped orifice in presence or absence of the anterior leaflet in various physiological stroke ratios. The results of the statistical analysis indicate that the formed vortex ring downstream of a D-shaped orifice is markedly non-axisymmetric, and presence of the anterior leaflet improves the ring's axisymmetry. This study suggests that the improvement of axisymmetry in presence of the anterior leaflet might be due to coupled dynamic interaction between rolling-up of the shear layer at the edges of the D-shaped orifice and the borders of the anterior leaflet. This interaction can reduce the non-uniformity in vorticity generation, which results in more axisymmetric behavior compared to the D-shaped orifice without the anterior leaflet.

  5. Blowing smoke rings in superfluid helium

    International Nuclear Information System (INIS)

    Allum, D.R.; McClintock, P.V.E.

    1977-01-01

    Among experiments designed to investigate the properties of superfluids, measurements are discussed which aim at determining the variation in the speed of an ion with the size of the electric field propelling it through liquid helium. The experimental set up using helium ions is described. The velocity-field characteristic shows an initial rise but at a higher electric field the ions exhibit the curious behaviour of slowing down before again increasing speed with force. The reason for this region of slowing down is here explained as being due to the fact that the charge is no longer carried by a free ion but, rather, by a charged vortex ring. As the ion speeds thorugh the liquid it suddenly creates a vortex ring and as one of the fundamental characteristics of a vortex ring is that its velocity is inversely proportional to its radius the speed reduction is explained. The subsequent rise in the characteristic indicates that the charge carriers are no longer straightforward charged vortex rings. This behaviour is attributed to ions 'falling off' their rings soon after creating them. It would appear that the force exerted by the electric field is so large that it overcomes the hydrodynamic force which binds the ion to the slowly moving vortex, enabling the ion to escape and accelerate away. In a final levelling off part of the characteristic curve it is considered that the ions are travelling faster than the critical velocity for roton creation, but are moving far below that for phonon creation. One may therefore conclude that the ion, as it travels through the liquid, transforms energy extracted from the electric field into rotons, which fan out forming a sort of wake behind it. (U.K.)

  6. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  7. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  8. How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

    Science.gov (United States)

    Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

    2012-11-01

    The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

  9. α-Skew π-McCoy Rings

    Directory of Open Access Journals (Sweden)

    Areej M. Abduldaim

    2013-01-01

    Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.

  10. HUGO HÄRING, ESPACIOS COREOGRÁFICOS DEL DEVENIR / Hugo Häring, choreographic spaces of becoming

    Directory of Open Access Journals (Sweden)

    Fernando Quesada López

    2010-11-01

    Full Text Available RESUMEN. El espacio puede leerse como el escenario para el despliegue de lo cotidiano o de acciones rituales. La arquitectura puede negociar forma y uso en el espacio desde lo protésico y desde lo coreográfico. Lo protésico opera como una disciplina ergonómica en la que la forma depende de usos previamente asignados. Lo coreográfico trabaja con y a través de formas que no responden directamente a ningún uso específico, sino que "esperan" la asignación de tal uso. Ambas estrategias parten del cuerpo como dato. Partiendo de lo orgánico y las prótesis, Hugo Häring desarrolló un corpus teórico muy rico dirigido a la propuesta de espacios coreográficos del devenir y conectado con la cultura alemana de la modernidad. Sin embargo, en sus propios proyectos, operó en el régimen protésico, proyectando espacios que funcionan como guiones teatrales para el despliegue de la vida. Para Häring, la metáfora orgánica debía culminar en una forma de espacio de los acontecimientos como estado de culminación de la cultura de las prótesis. SUMMARY. Space can be read as the scene for the unfolding of the day-to-day or of ritual actions. Architecture can negotiate form and use in space from the prosthetic and the choreographed. The prosthetic operates as an ergonomic discipline in which the form depends on previously assigned uses. The choreographed works with and through forms which do not directly respond to any specific use, but which "wait" for the allocation of such use. Both strategies come from the body as data. Starting off from the organic and the prostheses, Hugo Häring developed a very rich theoretical corpus directed to the proposal of choreographic spaces of becoming and connected with the German culture of modernity. Nevertheless, in his own projects, he operated in the prosthetic regime, projecting spaces that work as theatre scripts for the unfold.

  11. 1393 Ring Bus at JPL: Description and Status

    Science.gov (United States)

    Wysocky, Terry R.

    2007-01-01

    Completed Ring Bus IC V&V Phase - Ring Bus Test Plan Completed for SIM Project - Applicable to Other Projects Implemented a Avionics Bus Based upon the IEEE 1393 Standard - Excellent Starting Point for a General Purpose High-Speed Spacecraft Bus - Designed to Meet SIM Requirements for - Real-time deterministic, distributed systems. - Control system requirements - Fault detection and recovery Other JPL Projects Considering Implementation F'light Software Ring Bus Driver Module Began in 2006, Continues Participating in Standard Revision. Search for Earth-like planets orbiting nearby stars and measure the masses and orbits of the planets it finds. Survey 2000 nearby stars for planetary systems to learn whether our Solar System is unusual, or typical. Make a new catalog of star position 100 times more accurate than current measurements. Learn how our galaxy formed and will evolve by studying the dynamics of its stars. Critically test models of exactly how stars shine, including exotic objects like black holes, neutron stars and white dwarfs.

  12. Ring enhancement in recurrent gliomas

    International Nuclear Information System (INIS)

    Ogashiwa, Motohide; Takeuchi, Kazuo; Akai, Keiichiro

    1981-01-01

    The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas. (author)

  13. Ring enhancement in recurrent gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Ogashiwa, M; Takeuchi, K; Akai, K [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1981-08-01

    The clinical courses,CT scans, and postmortem reports for 6 glioma patients treated by surgery, radiation, and chemotherapy were reviewed. They underwent reoperation and/or retreatment with radiation or chemotherapy for recurrent tumors. CT scans taken at the time of recurrence or about one month prior to death showed ring enhancement of varied size and form after intensive treatment. The cases were examined histologically in correlation with the CT features and divided into two groups based on the pathological findings in the centers surrounded by areas of ring enhancement. The 1st group demonstrated a large necrotic area in the center, and the 2nd group, a cystic tumor. Tumor cells were found to have spread throughout the high-density areas around the necrotic area or cyst. However, gross differentiation between tumor and necrosis was difficult. In addition to an increase in cellularity, all cases demonstrated vascular proliferation, and dilatation of vessels in the sulci or sulci adjacent to gyri invaded by the tumor. The contrast enhancement corresponded well with the vascular proliferation in these areas. It is concluded that vascular proliferation or dilatation of vessels in and around the tumor is an important factor in demonstrating high-density areas in ring enhancement, while a cyst or necrosis in the tumor center is revealed as a low-density area in the CT scan of recurrent gliomas.

  14. VUV optical ring resonator for Duke storage ring free electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

    1995-12-31

    The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

  15. Change Ringing - communicating climate change through contemporary classical music

    Science.gov (United States)

    Kapur, Ravi; Osborn, Laurence; Shenai, Peter

    2016-04-01

    Change Ringing is a collaborative artwork by artist Peter Shenai and composer Laurence Osborn that forms around a playable sculpture and a large-scale composition. The sculpture incorporates a set of six bronze bells designed and cast by artist Peter Shenai. Their shapes are mathematically derived from graphic statistical representations of summer temperatures at seventeen-year intervals over the course of the twentieth century. Arranged according to the chronology of their corresponding data sets and struck in order, the bells voice a series of inharmonic spectra that communicate sonically the story of climate change during the twentieth century. This series forms the basis for Laurence Osborn's twenty-five minute composition, scored for string orchestra and the bells themselves. In Change Ringing, an artwork that combines music, sculpture, performance, and ritual, we want to move audiences and, in doing so, facilitate their engagement with ideas that are highly relevant today. We believe that the medium of musically organized sound, so often wrongly dismissed as "abstract" and non-referential, can be a more than adequate reflection of lived human experience in the 21st Century, and we work in the hope that Change Ringing will connect with contemporary audiences on the most fundamental level.

  16. Two dynamin-like proteins stabilize FtsZ rings during Streptomyces sporulation.

    Science.gov (United States)

    Schlimpert, Susan; Wasserstrom, Sebastian; Chandra, Govind; Bibb, Maureen J; Findlay, Kim C; Flärdh, Klas; Buttner, Mark J

    2017-07-25

    During sporulation, the filamentous bacteria Streptomyces undergo a massive cell division event in which the synthesis of ladders of sporulation septa convert multigenomic hyphae into chains of unigenomic spores. This process requires cytokinetic Z-rings formed by the bacterial tubulin homolog FtsZ, and the stabilization of the newly formed Z-rings is crucial for completion of septum synthesis. Here we show that two dynamin-like proteins, DynA and DynB, play critical roles in this process. Dynamins are a family of large, multidomain GTPases involved in key cellular processes in eukaryotes, including vesicle trafficking and organelle division. Many bacterial genomes encode dynamin-like proteins, but the biological function of these proteins has remained largely enigmatic. Using a cell biological approach, we show that the two Streptomyces dynamins specifically localize to sporulation septa in an FtsZ-dependent manner. Moreover, dynamin mutants have a cell division defect due to the decreased stability of sporulation-specific Z-rings, as demonstrated by kymographs derived from time-lapse images of FtsZ ladder formation. This defect causes the premature disassembly of individual Z-rings, leading to the frequent abortion of septum synthesis, which in turn results in the production of long spore-like compartments with multiple chromosomes. Two-hybrid analysis revealed that the dynamins are part of the cell division machinery and that they mediate their effects on Z-ring stability during developmentally controlled cell division via a network of protein-protein interactions involving DynA, DynB, FtsZ, SepF, SepF2, and the FtsZ-positioning protein SsgB.

  17. Dynamics of the evaporative dewetting of a volatile liquid film confined within a circular ring.

    Science.gov (United States)

    Sun, Wei; Yang, Fuqian

    2015-04-07

    The dewetting dynamics of a toluene film confined within a copper ring on a deformable PMMA film is studied. The toluene film experiences evaporation and dewetting, which leads to the formation of a circular contact line around the center of the copper ring. The contact line recedes smoothly toward the copper ring at a constant velocity until reaching a dynamic "stick" state to form the first circular polymer ridge. The average receding velocity is found to be dependent on the dimensions of the copper ring (the copper ring diameter and the cross-sectional diameter of the copper wire) and the thickness of the PMMA films. A model is presented to qualitatively explain the evaporative dewetting phenomenon.

  18. Interaction Region Design for a Ring-Ring LHeC

    CERN Document Server

    Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

    2011-01-01

    tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

  19. The properties of Ge quantum rings deposited by pulsed laser deposition.

    Science.gov (United States)

    Ma, Xiying

    2010-07-01

    SiGe ring-shape nanostructures have attracted much research interest because of the interesting morphology, mechanical, and electromagnetic properties. In this paper, we present the planar Ge nanorings with well-defined sharp edges self-assembled on Si (100) matrix prepared with pulsed laser deposition (PLD) in the present of Ar gas. The transforming mechanism of the droplets is discussed, which a dynamic deformation model has been developed to simulate the self-transforming process of the droplets. The rings were found to be formed in two steps: from droplets to cones and from cones to rings via an elastic self-deforming process, which were likely to be driven by the lateral strain of Ge/Si layers and the surface tension.

  20. Electron Cloud Build Up and Instability in the CLIC Damping Rings

    CERN Document Server

    Rumolo, G; Papaphilippou, Y

    2008-01-01

    Electron cloud can be formed in the CLIC positron damping ring and cause intolerable tune shift and beam instability. Build up simulations with the Faktor2 code, developed at CERN, have been done to predict the cloud formation in the arcs and wigglers of the damping rings. HEADTAIL simulations have been used to study the effect of this electron cloud on the beam and assess the thresholds above which the electron cloud instability would set in.

  1. A multipole-expanded effective field theory for vortex ring-sound interactions

    Science.gov (United States)

    Garcia-Saenz, Sebastian; Mitsou, Ermis; Nicolis, Alberto

    2018-02-01

    The low-energy dynamics of a zero temperature superfluid or of the compressional modes of an ordinary fluid can be described by a simple effective theory for a scalar field — the superfluid `phase'. However, when vortex lines are present, to describe all interactions in a local fashion one has to switch to a magnetic-type dual two-form description, which comes with six degrees of freedom (in place of one) and an associated gauge redundancy, and is thus considerably more complicated. Here we show that, in the case of vortex rings and for bulk modes that are much longer than the typical ring size, one can perform a systematic multipole expansion of the effective action and recast it into the simpler scalar field language. In a sense, in the presence of vortex rings the non-single valuedness of the scalar can be hidden inside the rings, and thus out of the reach of the multipole expansion. As an application of our techniques, we compute by standard effective field theory methods the sound emitted by an oscillating vortex ring.

  2. Rings Research in the Next Decade

    Science.gov (United States)

    Burns, J. A.; Tiscareno, M. S.

    2009-12-01

    The study of planetary ring systems forms a key component of planetary science for several reasons: 1) The evolution and current states of planets and their satellites are affected in many ways by rings, while 2) conversely, properties of planets and moons and other solar system populations are revealed by their effects on rings; 3) highly structured and apparently delicate ring systems may be bellwethers, constraining various theories of the origin and evolution of their entire planetary system; and finally, 4) planetary rings provide an easily observable analogue to other astrophysical disk systems, enabling real “ground truth” results applicable to disks much more remote in space and/or time, including proto-planetary disks, circum-stellar disks, and even galaxies. Significant advances have been made in rings science in the past decade. The highest-priority rings research recommendations of the last Planetary Science Decadal Survey were to operate and extend the Cassini orbiter mission at Saturn; this has been done with tremendous success, accounting for much of the progress made on key science questions, as we will describe. Important progress in understanding the rings of Saturn and other planets has also come from Earth-based observational and theoretical work, again as prioritized by the last Decadal Survey. However, much important work remains to be done. At Saturn, the Cassini Solstice Mission must be brought to a successful completion. Priority should also be placed on sending spacecraft to Neptune and/or Uranus, now unvisited for more than 20 years. At Jupiter and Pluto, opportunities afforded by visiting spacecraft capable of studying rings should be exploited. On Earth, the need for continued research and analysis remains strong, including in-depth analysis of rings data already obtained, numerical and theoretical modeling work, laboratory analysis of materials and processes analogous to those found in the outer solar system, and continued Earth

  3. (μ-3-Acetyl-5-carboxylato-4-methylpyrazolido-1:2κ4N2,O3:N1,O5-μ-chlorido-tetrapyridine-1κ2N,2κ2N-chlorido-1κCl-dicopper(II propan-2-ol solvate

    Directory of Open Access Journals (Sweden)

    Sergey Malinkin

    2009-10-01

    Full Text Available The title compound, [Cu2(C7H6N2O3Cl2(C5H5N4]·C3H8O, is a binuclear pyrazolate complex, in which the two CuII atoms have different coordination numbers and are connected by a bridging Cl atom. One CuII atom has a distorted square-pyramidal coordination environment formed by two pyridine N atoms, one bridging Cl atom and an N,O-chelating pyrazolate ligand. The other CuII atom adopts an octahedral geometry defined by two pyridine N atoms at the axial positions, two Cl atoms and the coordinated pyrazolate ligand in the equatorial plane. An O—H...O hydrogen bond connects the complex molecules and propan-2-ol solvent molecules into pairs. These pairs form columns along the a axis.

  4. Planar LIF observation of unburned fuel escaping the upper ring-land crevice in an SI engine

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.M.; Cloutman, L.D.

    1997-01-01

    PLIF has been used to observe the in-cylinder transport of unburned fuel that, while trapped in the ring-land and ring-groove crevices, survives combustion in the propagating flame. Away from the top-ring gap, we detect a wall-jet comprised of unburned charge exiting the top ring-land crevice opening. At the location of the top-ring gap, we observed unburned fuel lying in the cool boundary layer along the cylinder wall during the later stages of the expansion stroke. This layer is scraped into the roll-up vortex during the exhaust stroke. These data lead us to conclude that away from the end gap, unburned, high pressure charge, trapped between the two compression rings escapes as a wall jet after ring-reversal near the bottom center. Conversely, at the ring gap, when the cylinder pressure drops below the pressure between the compression rings, the trapped charge escapes through the gap and forms a thin layer on the cylinder wall.

  5. Uniquely Strongly Clean Group Rings

    Institute of Scientific and Technical Information of China (English)

    WANG XIU-LAN

    2012-01-01

    A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

  6. Ring Chromosome 17 Not Involving the Miller-Dieker Region: A Case with Drug-Resistant Epilepsy.

    Science.gov (United States)

    Coppola, Antonietta; Morrogh, Deborah; Farrell, Fiona; Balestrini, Simona; Hernandez-Hernandez, Laura; Krithika, S; Sander, Josemir W; Waters, Jonathan J; Sisodiya, Sanjay M

    2017-12-01

    Chromosomal abnormalities are often identified in people with neurodevelopmental disorders including intellectual disability, autism, and epilepsy. Ring chromosomes, which usually involve gene copy number loss, are formed by fusion of subtelomeric or telomeric chromosomal regions. Some ring chromosomes, including ring 14, 17, and 20, are strongly associated with seizure disorders. We report an individual with a ring chromosome 17, r(17)(p13.3q25.3), with a terminal 17q25.3 deletion and no short arm copy number loss, and with a phenotype characterized by intellectual disability and drug-resistant epilepsy, including a propensity for nonconvulsive status epilepticus.

  7. Structural, optical, mechanical and density functional theory studies of 1H-pyrazol-2-ium hydrogen oxalate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Devi, P. Karthiga, E-mail: karthvi19@gmail.com; Venkatachalam, K.

    2016-11-01

    In the present work, we have grown 1H- pyrazol-2-ium hydrogen oxalate single crystal by slow evaporation solution growth technique. The lattice parameters are determined from single crystal X ray diffraction studies. The functional groups present in the compound are confirmed by Fourier transform infrared spectroscopy. UV-Vis analysis shows that the crystal has a wide transparency window. Vicker's hardness test has been carried out to estimate the stiffness constant, fracture toughness, brittleness index and yield strength of the crystal. Density functional study B3LYP method at 6-31 G (d, p) has been performed to study the optimized structure, HOMO-LUMO energy gap, hyperpolarizability and thermodynamic properties. - Highlights: • The title compound was analyzed using FTIR and UV–Vis spectroscopy. • Mechanical study was carried out using Vicker's hardness test. • Optimized molecular geometry was determined using DFT method. • Hydrogen bonding interaction was studied through NBO analysis.

  8. Damping Ring R&D at CESR-TA

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, David L. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics

    2015-01-23

    Accelerators that collide high energy beams of matter and anti-matter are essential tools for the investigation of the fundamental constituents of matter, and the search for new forms of matter and energy. A “Linear Collider” is a machine that would bring high energy and very compact bunches of electrons and positrons (anti-electrons) into head-on collision. Such a machine would produce (among many other things) the newly discovered Higgs particle, enabling a detailed study of its properties. Among the most critical and challenging components of a linear collider are the damping rings that produce the very compact and intense beams of electrons and positrons that are to be accelerated into collision. Hot dilute particle beams are injected into the damping rings, where they are compressed and cooled. The size of the positron beam must be reduced more than a thousand fold in the damping ring, and this compression must be accomplished in a fraction of a second. The cold compact beams are then extracted from the damping ring and accelerated into collision at high energy. The proposed International Linear Collider (ILC), would require damping rings that routinely produce such cold, compact and intense beams. The goal of the Cornell study was a credible design for the damping rings for the ILC. Among the technical challenges of the damping rings; the development of instrumentation that can measure the properties of the very small beams in a very narrow window of time, and mitigation of the forces that can destabilize the beams and prevent adequate cooling, or worse lead to beam loss. One of the most pernicious destabilizing forces is due to the formation of clouds of electrons in the beam pipe. The electron cloud effect is a phenomenon in particle accelerators in which a high density of low energy electrons, build up inside the vacuum chamber. At the outset of the study, it was anticipated that electron cloud effects would limit the intensity of the positron ring

  9. Structure and catalytic activation of the TRIM23 RING E3 ubiquitin ligase: DAWIDZIAK et al.

    Energy Technology Data Exchange (ETDEWEB)

    Dawidziak, Daria M. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Sanchez, Jacint G. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Wagner, Jonathan M. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Ganser-Pornillos, Barbie K. [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia; Pornillos, Owen [Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville Virginia

    2017-07-24

    Tripartite motif (TRIM) proteins comprise a large family of RING-type ubiquitin E3 ligases that regulate important biological processes. An emerging general model is that TRIMs form elongated antiparallel coiled-coil dimers that prevent interaction of the two attendant RING domains. The RING domains themselves bind E2 conjugating enzymes as dimers, implying that an active TRIM ligase requires higher-order oligomerization of the basal coiled-coil dimers. Here, we report crystal structures of the TRIM23 RING domain in isolation and in complex with an E2–ubiquitin conjugate. Our results indicate that TRIM23 enzymatic activity requires RING dimerization, consistent with the general model of TRIM activation.

  10. Mechanical improvement of metal reinforcement rings for a finite ring-shaped superconducting bulk

    Science.gov (United States)

    Huang, Chen-Guang; Zhou, You-He

    2018-03-01

    As a key technique, reinforcement of type-II superconducting bulks with metal rings can efficiently improve their mechanical properties to enhance the maximum trapped field. In this paper, we study the magnetostrictive and fracture behaviors of a finite superconducting ring bulk reinforced by three typical reinforcing structures composed of metal rings during the magnetizing process by means of the minimization of magnetic energy and the finite element method. After a field-dependent critical current density is adopted, the magnetostriction, pinning-induced stress, and crack tip stress intensity factor are calculated considering the demagnetization effects. The results show that the mechanical properties of the ring bulk are strongly dependent on the reinforcing structure and the material and geometrical parameters of the metal rings. Introducing the metal ring can significantly reduce the hoop stress, and the reduction effect by internal reinforcement is much improved relative to external reinforcement. By comparison, bilateral reinforcement seems to be the best candidate structure. Only when the metal rings have particular Young's modulus and radial thickness will they contribute to improve the mechanical properties the most. In addition, if an edge crack is pre-existing in the ring bulk, the presence of metal rings can effectively avoid crack propagation since it reduces the crack tip stress intensity factor by nearly one order of magnitude.

  11. Self-organized formation of GaSb/GaAs quantum rings.

    Science.gov (United States)

    Timm, R; Eisele, H; Lenz, A; Ivanova, L; Balakrishnan, G; Huffaker, D L; Dähne, M

    2008-12-19

    Ring-shaped GaSb/GaAs quantum dots, grown by molecular beam epitaxy, were studied using cross-sectional scanning tunneling microscopy. These quantum rings have an outer shape of a truncated pyramid with baselengths around 15 nm and heights of about 2 nm but are characterized by a clear central opening extending over about 40% of the outer baselength. They form spontaneously during the growth and subsequent continuous capping of GaSb/GaAs quantum dots due to the large strain and substantial As-for-Sb exchange reactions leading to strong Sb segregation.

  12. Quantum interference of ballistic carriers in one-dimensional semiconductor rings

    International Nuclear Information System (INIS)

    Bagraev, N.T.; Buravlev, A.D.; Klyachkin, L.E.; Malyarenko, A.M.; Ivanov, V.K.; Rykov, S.A.; Shelykh, I.A.

    2000-01-01

    Quantum interference of ballistic carriers has been studied for the first time, using one-dimensional rings formed by quantum wire pairs in self-assembled silicon quantum wells. Energy dependencies of the transmission coefficient is calculated as a function of the length and modulation of the quantum wire pairs separated by a unified drain-source system or the quantum point contacts. The quantum conductance is predicted to be increased by a factor of four using the unified drain-source system as a result of the quantum interference. Theoretical dependencies are revealed by the quantum conductance oscillations created by the deviations of both the drain-source voltage and external magnetic field inside the silicon one-dimensional rings. The results obtained put forward a basis to create the Aharonov-Bohm interferometer using the silicon one-dimensional ring [ru

  13. Ring correlations in random networks.

    Science.gov (United States)

    Sadjadi, Mahdi; Thorpe, M F

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  14. rac-1-[6-Hydroxy-4-(4-methoxyphenyl-3,6-dimethyl-4,5,6,7-tetrahydro-2H-indazol-5-yl]ethanone

    Directory of Open Access Journals (Sweden)

    Konstantin A. Potekhin

    2013-02-01

    Full Text Available The title compound, C18H22N2O3, represents a (4S,5R,6S-stereoisomer, crystallizing as a racemate in a centrosymmetric space group. The six-membered aliphatic ring adopts a half-chair conformation, with the hydroxy- and acetyl-substituted C atoms deviating by 0.458 (2 and −0.366 (2 Å, respectively, from the plane defined by other four ring atoms. The pyrazole ring is essentially planar [r.m.s deviation = 0.004 (2 Å]. In the crystal, the molecules are linked into chains along the b axis by N—H...N hydrogen bonds. The chains are linked by O—H...N hydrogen bonds into layers parallel to the bc plane.

  15. Packing Polymorphism of Dapivirine and Its Impact on the Performance of a Dapivirine-Releasing Silicone Elastomer Vaginal Ring.

    Science.gov (United States)

    McCoy, Clare F; Murphy, Diarmaid J; Boyd, Peter; Derrick, Tiffany; Spence, Patrick; Devlin, Brid; Malcolm, R Karl

    2017-08-01

    A silicone elastomer vaginal ring providing sustained release over 28 days of the anti-retroviral microbicide dapivirine has recently completed phase III clinical testing and showed moderate protection against HIV acquisition. In support of the product licensure program, we report the impact of dapivirine packing polymorphism on the thermal and solubility characteristics of dapivirine and on the in vitro performance of the 25 mg dapivirine ring product. This is the first time that polymorphism has been reported for a drug-releasing vaginal ring product. Thermal, particle size, powder X-ray diffraction, and thermodynamic solubility analyses of dapivirine polymorphic forms I and IV, both of which are persistent at room temperature and with form I being the thermodynamically stable form, were conducted for both micronized and non-micronized materials. No significant differences in solubility between DPV forms I and IV were observed in media commonly used for in vitro release testing. Matrix-type silicone elastomer vaginal rings were manufactured and the impact of dapivirine polymorphism on key in vitro parameters (compression and tensile behavior; content assay; in vitro release; residual content assay) was investigated. The data demonstrate that dapivirine packing polymorphism has no significant impact on in vitro performance of the 25 mg dapivirine vaginal ring. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  16. Lie algebras for the Dirac-Clifford ring

    International Nuclear Information System (INIS)

    Mignaco, J.A.; Linhares, C.A.

    1992-01-01

    It is shown in a general way that the Dirac-Clifford ring formed by the Dirac matrices and all their products, for all even and odd spacetime dimensions D, span the cumulation algebras SU(2 D/2 ) for even D and SU(2 (D- 1 )/2 ) + SU(2 (D-1)/2 ) for odd D. Some physical consequences of these results are discussed. (author)

  17. Alpha - Skew Pi - Armendariz Rings

    Directory of Open Access Journals (Sweden)

    Areej M Abduldaim

    2018-03-01

    Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

  18. Organically Modified Silica with Pyrazole-3-carbaldehyde as a New Sorbent for Solid-Liquid Extraction of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Smaail Radi

    2013-12-01

    Full Text Available A new chelating matrix, SiNP, has been prepared by immobilizing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel modified with 3-aminopropyl-trimethoxysilane. This new chelating material was well characterized by elemental analysis, FT-IR spectroscopy, cross polarization magic angle spinning solid state 13C-NMR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore size, and scanning electron microscopy (SEM. The new product exhibits good chemical and thermal stability as determined by thermogravimetry curves (TGA. The new prepared material was used as an adsorbent for the solid-phase extraction (SPE of Pb(II, Cd(II, Cu(II and Zn(II from aqueous solutions using a batch method, prior to their determination by flame atomic adsorption spectrometry. The adsorption capacity was investigated using kinetics and pH effects. Common coexisting ions did not interfere with separation and determination.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  20. Plasma-ring, fast-opening switch

    International Nuclear Information System (INIS)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.

    1986-01-01

    The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

  1. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  2. The LSU Electron Storage Ring, the first commercially-built storage ring

    International Nuclear Information System (INIS)

    Sah, R.

    1990-01-01

    The Brobeck Division of Maxwell Laboratories, Inc., is building the first industrially-produced storage ring. It will be located at Louisiana State University (LSU) at the Center for Advanced Microstructures and Devices (CAMD) in Baton Rouge. The purpose of this electron storage ring is to provide intense beams of x-rays to advance the state-of-the-art in lithography and to permit research in a broad area. This facility consists of a 1.2 GeV, 400 mA electron storage ring with a 200 MeV linac injector. The magnet lattice is a Chasman-Green design (double-bend achromat), and the ring circumference is 55.2 meters. There are four 3.0 meter, dispersion-free straight sections, one for injection, one for the 500 MHz RF cavity, and two for possible future insertion devices. The storge ring construction project is in the detailed-design stage, and many systems are in the initial stages of fabrication. 4 figs., 1 tab

  3. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

  4. ALK5 kinase inhibitory activity and synthesis of 2,3,4-substituted 5,5-dimethyl-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoles

    Czech Academy of Sciences Publication Activity Database

    Řezníčková, Eva; Tenora, L.; Pospíšilová, Pavlína; Galeta, J.; Jorda, Radek; Berka, K.; Majer, Pavel; Potáček, M.; Kryštof, Vladimír

    2017-01-01

    Roč. 127, FEB 15 (2017), s. 632-642 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1204; GA ČR(CZ) GA15-15264S; GA MŠk(CZ) LM2015047 Institutional support: RVO:61389030 ; RVO:61388963 Keywords : i-receptor kinase * beta signaling pathway * small- molecule inhibitor * tgf-beta * domain inhibitors * growth * fibrosis * cancer * potent * series * Transforming growth factor beta receptor I * Protein kinase * Inhibitor * Substituted pyrrolo[1,2-b]pyrazoles Subject RIV: FR - Pharmacology ; Medidal Chemistry OBOR OECD: Pharmacology and pharmacy; Pharmacology and pharmacy (UOCHB-X) Impact factor: 4.519, year: 2016

  5. Computational study of hydrogen shifts and ring-opening mechanisms in α-pinene ozonolysis products

    DEFF Research Database (Denmark)

    Kurtén, Theo; Rissanen, Matti P.; Mackeprang, Kasper

    2015-01-01

    , sterically unhindered) H-shifts of all four peroxy radicals formed in the ozonolysis of α-pinene using density functional (ωB97XD) and coupled cluster [CCSD(T)-F12] theory. In contrast to the related but chemically simpler cyclohexene ozonolysis system, none of the calculated H-shifts have rate constants...... products in the α-pinene ozonolysis system, additional ring-opening reaction mechanisms breaking the cyclobutyl ring are therefore needed. We further investigate possible uni- and bimolecular pathways for opening the cyclobutyl ring in the α-pinene ozonolysis system....

  6. Evaluation of ring impedance of the Photon Factory storage ring

    International Nuclear Information System (INIS)

    Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

    1992-05-01

    The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

  7. Construction of Polynuclear Lanthanide (Ln = Dy(III), Tb(III), and Nd(III)) Cage Complexes Using Pyridine-Pyrazole-Based Ligands: Versatile Molecular Topologies and SMM Behavior.

    Science.gov (United States)

    Bala, Sukhen; Sen Bishwas, Mousumi; Pramanik, Bhaskar; Khanra, Sumit; Fromm, Katharina M; Poddar, Pankaj; Mondal, Raju

    2015-09-08

    Employment of two different pyridyl-pyrazolyl-based ligands afforded three octanuclear lanthanide(III) (Ln = Dy, Tb) cage compounds and one hexanuclear neodymium(III) coordination cage, exhibiting versatile molecular architectures including a butterfly core. Relatively less common semirigid pyridyl-pyrazolyl-based asymmetric ligand systems show an interesting trend of forming polynuclear lanthanide cage complexes with different coordination environments around the metal centers. It is noteworthy here that construction of lanthanide complex itself is a challenging task in a ligand system as soft N-donor rich as pyridyl-pyrazol. We report herein some lanthanide complexes using ligand containing only one or two O-donors compare to five N-coordinating sites. The resultant multinuclear lanthanide complexes show interesting magnetic and spectroscopic features originating from different spatial arrangements of the metal ions. Alternating current (ac) susceptibility measurements of the two dysprosium complexes display frequency- and temperature-dependent out-of-phase signals in zero and 0.5 T direct current field, a typical characteristic feature of single-molecule magnet (SMM) behavior, indicating different energy reversal barriers due to different molecular topologies. Another aspect of this work is the occurrence of the not-so-common SMM behavior of the terbium complex, further confirmed by ac susceptibility measurement.

  8. Comparing Sources of Storm-Time Ring Current O+

    Science.gov (United States)

    Kistler, L. M.

    2015-12-01

    The first observations of the storm-time ring current composition using AMPTE/CCE data showed that the O+ contribution to the ring current increases significantly during storms. The ring current is predominantly formed from inward transport of the near-earth plasma sheet. Thus the increase of O+ in the ring current implies that the ionospheric contribution to the plasma sheet has increased. The ionospheric plasma that reaches the plasma sheet can come from both the cusp and the nightside aurora. The cusp outflow moves through the lobe and enters the plasma sheet through reconnection at the near-earth neutral line. The nightside auroral outflow has direct access to nightside plasma sheet. Using data from Cluster and the Van Allen Probes spacecraft, we compare the development of storms in cases where there is a clear input of nightside auroral outflow, and in cases where there is a significant cusp input. We find that the cusp input, which enters the tail at ~15-20 Re becomes isotropized when it crosses the neutral sheet, and becomes part of the hot (>1 keV) plasma sheet population as it convects inward. The auroral outflow, which enters the plasma sheet closer to the earth, where the radius of curvature of the field line is larger, does not isotropize or become significantly energized, but remains a predominantly field aligned low energy population in the inner magnetosphere. It is the hot plasma sheet population that gets accelerated to high enough energies in the inner magnetosphere to contribute strongly to the ring current pressure. Thus it appears that O+ that enters the plasma sheet further down the tail has a greater impact on the storm-time ring current than ions that enter closer to the earth.

  9. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  10. Structural, thermal, morphological and biological studies of proton-transfer complexes formed from 4-aminoantipyrine with quinol and picric acid

    Science.gov (United States)

    Adam, Abdel Majid A.

    2013-03-01

    4-Aminoantipyrine (4AAP) is widely used in the pharmaceutical industry, biochemical experiments and environmental monitoring. However, residual amounts of 4AAP in the environment may pose a threat to human health. To provide basic data that can be used to extract or eliminate 4AAP from the environment, the proton-transfer complexes of 4AAP with quinol (QL) and picric acid (PA) were synthesized and spectroscopically investigated. The interactions afforded two new proton-transfer salts named 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium-4-hydroxyphenolate and 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium-2,4,6-trinitrophenolate for QL and PA, respectively, via a 1:1 stoichiometry. Elemental analysis (CHN), electronic absorption, spectrophotometric titration, IR, Raman, 1H NMR and X-ray diffraction were used to characterize the new products. The thermal stability of the synthesized CT complexes was investigated using thermogravimetric (TG) analyses, and the morphology and particle size of these complexes were obtained from scanning electron microscopy (SEM). It was found that PA and 4AAP immediately formed a yellow precipitate with a remarkable sponge-like morphology and good thermal stability up to 180 °C. Finally, the biological activities of the newly synthesized CT complexes were tested for their antibacterial and antifungal activities. The results indicated that the [(4AAP)(QL)] complex exhibited strong antimicrobial activities against various bacterial and fungal strains compared with standard drugs.

  11. Gas chromatographic analysis of reactive carbonyl compounds formed from lipids upon UV-irradiation

    International Nuclear Information System (INIS)

    Dennis, K.J.; Shibamoto, T.

    1990-01-01

    Peroxidation of lipids produces carbonyl compounds; some of these, e.g., malonaldehyde and 4-hydroxynonenal, are genotoxic because of their reactivity with biological nucleophiles. Analysis of the reactive carbonyl compounds is often difficult. The methylhydrazine method developed for malonaldehyde analysis was applied to simultaneously measure the products formed from linoleic acid, linolenic acid, arachidonic acid, and squalene upon ultraviolet-irradiation (UV-irradiation). The photoreaction products, saturated monocarbonyl, alpha,beta-unsaturated carbonyls, and beta-dicarbonyls, were derivatized with methylhydrazine to give hydrazones, pyrazolines, and pyrazoles, respectively. The derivatives were analyzed by gas chromatography and gas chromatography-mass spectrometry. Lipid peroxidation products identified included formaldehyde, acetaldehyde, acrolein, malonaldehyde, n-hexanal, and 4-hydroxy-2-nonenal. Malonaldehyde levels formed upon 4 hr of irradiation were 0.06 micrograms/mg from squalene, 2.4 micrograms/mg from linolenic acid, and 5.7 micrograms/mg from arachidonic acid. Significant levels of acrolein (2.5 micrograms/mg) and 4-hydroxy-2-nonenal (0.17 micrograms/mg) were also produced from arachidonic acid upon 4 hr irradiation

  12. FORMATION OF CENTAURS’ RINGS THROUGH THEIR PARTIAL TIDAL DISRUPTION DURING PLANETARY ENCOUNTERS

    Energy Technology Data Exchange (ETDEWEB)

    Hyodo, Ryuki; Charnoz, Sébastien [Institut de Physique du Globe, F-75005 Paris, France (France); Genda, Hidenori [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ohtsuki, Keiji [Department of Planetology, Kobe University, Kobe 657-8501 (Japan)

    2016-09-01

    Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20−50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3−6 km s{sup −1} and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

  13. FORMATION OF CENTAURS’ RINGS THROUGH THEIR PARTIAL TIDAL DISRUPTION DURING PLANETARY ENCOUNTERS

    International Nuclear Information System (INIS)

    Hyodo, Ryuki; Charnoz, Sébastien; Genda, Hidenori; Ohtsuki, Keiji

    2016-01-01

    Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20−50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3−6 km s"−"1 and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

  14. Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i

    Science.gov (United States)

    Orr, T.R.

    2011-01-01

    Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīlauea Volcano during November 2005–July 2006. During this period, tilt data, time-lapse images, and field observations showed that episodic tilt changes at the nearby Pu‘u ‘Ō‘ō cone, the shallow magmatic source reservoir, were directly related to fluctuations in the level of lava in the active lava tube, with periods of deflation at Pu‘u ‘Ō‘ō correlating with increases in the level of the lava stream surface. Increases in lava level are interpreted as increases in lava flux, and were coincident with lava breakouts from shatter rings constructed over the lava tube. The repetitive behavior of the lava flux changes, inferred from the nearly continuous tilt oscillations, suggests that shatter rings form from the repeated rise and fall of a portion of a lava tube roof. The locations of shatter rings along the active lava tube suggest that they form where there is an abrupt decrease in flow velocity through the tube, e.g., large increase in tube width, abrupt decrease in tube slope, and (or) sudden change in tube direction. To conserve volume, this necessitates an abrupt increase in lava stream depth and causes over-pressurization of the tube. More than a hundred shatter rings have been identified on volcanoes on Hawai‘i and Maui, and dozens have been reported from basaltic lava fields in Iceland, Australia, Italy, Samoa, and the mainland United States. A quick study of other basaltic lava fields worldwide, using freely available satellite imagery, suggests that they might be even more common than previously thought. If so, this confirms that episodic

  15. Some Aspects of Ring Theory

    CERN Document Server

    Herstein, IN

    2011-01-01

    S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

  16. (μ-3-Acetyl-5-carboxyl­ato-4-methyl­pyrazolido-1:2κ4 N 2,O 3:N 1,O 5)-μ-chlorido-tetra­pyridine-1κ2 N,2κ2 N-chlorido-1κCl-dicopper(II) propan-2-ol solvate

    Science.gov (United States)

    Malinkin, Sergey; Penkova, Larisa; Pavlenko, Vadim A.; Haukka, Matti; Fritsky, Igor O.

    2009-01-01

    The title compound, [Cu2(C7H6N2O3)Cl2(C5H5N)4]·C3H8O, is a binuclear pyrazolate complex, in which the two CuII atoms have different coordination numbers and are connected by a bridging Cl atom. One CuII atom has a distorted square-pyramidal coordination environment formed by two pyridine N atoms, one bridging Cl atom and an N,O-chelating pyrazolate ligand. The other CuII atom adopts an octa­hedral geometry defined by two pyridine N atoms at the axial positions, two Cl atoms and the coordinated pyrazolate ligand in the equatorial plane. An O—H⋯O hydrogen bond connects the complex mol­ecules and propan-2-ol solvent mol­ecules into pairs. These pairs form columns along the a axis. PMID:21577764

  17. Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

    Directory of Open Access Journals (Sweden)

    Oleksandr Makeyev

    2016-06-01

    Full Text Available Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1-polar electrode with n rings using the (4n + 1-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2 and quadripolar (n = 3 electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected.

  18. Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

    Science.gov (United States)

    Makeyev, Oleksandr; Besio, Walter G.

    2016-01-01

    Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933

  19. Radar imaging of Saturn's rings

    Science.gov (United States)

    Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

    2005-09-01

    We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  1. Study of improvement in 1st ring`s gas-seal; Top ring no gas seal seino kojo no kento

    Energy Technology Data Exchange (ETDEWEB)

    Ando, H; Tateishi, Y; Fujimura, K; Hitosugi, H [Nippon Piston Ring Co. Ltd., Tokyo (Japan)

    1997-10-01

    The authors studied the effect of an angle of 1st ring twist on the amount of blow-by concerning higher speed/higher output engines for motorcycles. As a result, the authors found the twist made the ring restrained in a ring groove of piston , and confirmed its suitable range for blow-by. By means of the developed optimization method, the authors have achieved significant reduction in blow-by at high engine speed. 1 ref., 9 figs., 2 tabs.

  2. Polymers Containing 1, 3, 4-Oxadiazole Rings for Advanced Materials

    Directory of Open Access Journals (Sweden)

    Mariana-Dana Damaceanu

    2011-10-01

    Full Text Available This paper presents the synthesis, properties and potential applications of new polymers containing 1, 3, 4-oxadiazole rings, tacking into account the requirements of the modern technologies. Two classes of polymers containing oxadiazole rings were approached: polyamides and polyimides. All the polymers were characterized with respect to the identification of their chemical structure, solubility, molecular weights, film forming ability, thermal, dielectric and optical properties, and the behaviour of polyoxadiazole films upon irradiation with pulsed KrF laser. All the properties were discussed in correlation with their chemical structure and compared with those of related polymers.

  3. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  4. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

    2013-01-01

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  5. ring og refleksion

    DEFF Research Database (Denmark)

    Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

    State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

  6. Birth Control Ring

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

  7. Ring with changeable radiation dosimeter

    International Nuclear Information System (INIS)

    Collica, C.; Epifano, L.; Farella, R.

    1976-01-01

    A ring for housing a disc of radiation measuring material is described comprising a band having a circular shape and a housing integral with the band. The housing comprises a hollow cylindrical section substantially normal to the band surface and terminating in an inwardly disposed annular flange which defines a substantially circular aperture. In a preferred embodiment of the invention a retaining protrusion formed on the inside of the cylindrical section and spaced from the annular flange is provided to retain a plurality of discs mounted in the housing in layered fashion

  8. Spontaneous actin dynamics in contractile rings

    Science.gov (United States)

    Kruse, Karsten; Wollrab, Viktoria; Thiagarajan, Raghavan; Wald, Anne; Riveline, Daniel

    Networks of polymerizing actin filaments are known to be capable to self-organize into a variety of structures. For example, spontaneous actin polymerization waves have been observed in living cells in a number of circumstances, notably, in crawling neutrophils and slime molds. During later stages of cell division, they can also spontaneously form a contractile ring that will eventually cleave the cell into two daughter cells. We present a framework for describing networks of polymerizing actin filaments, where assembly is regulated by various proteins. It can also include the effects of molecular motors. We show that the molecular processes driven by these proteins can generate various structures that have been observed in contractile rings of fission yeast and mammalian cells. We discuss a possible functional role of each of these patterns. The work was supported by Agence Nationale de la Recherche, France, (ANR-10-LABX-0030-INRT) and by Deutsche Forschungsgemeinschaft through SFB1027.

  9. A numerical study of viscous vortex rings using a spectral method

    Science.gov (United States)

    Stanaway, S. K.; Cantwell, B. J.; Spalart, Philippe R.

    1988-01-01

    Viscous, axisymmetric vortex rings are investigated numerically by solving the incompressible Navier-Stokes equations using a spectral method designed for this type of flow. The results presented are axisymmetric, but the method is developed to be naturally extended to three dimensions. The spectral method relies on divergence-free basis functions. The basis functions are formed in spherical coordinates using Vector Spherical Harmonics in the angular directions, and Jacobi polynomials together with a mapping in the radial direction. Simulations are performed of a single ring over a wide range of Reynolds numbers (Re approximately equal gamma/nu), 0.001 less than or equal to 1000, and of two interacting rings. At large times, regardless of the early history of the vortex ring, it is observed that the flow approaches a Stokes solution that depends only on the total hydrodynamic impulse, which is conserved for all time. At small times, from an infinitely thin ring, the propagation speeds of vortex rings of varying Re are computed and comparisons are made with the asymptotic theory by Saffman. The results are in agreement with the theory; furthermore, the error is found to be smaller than Saffman's own estimate by a factor square root ((nu x t)/R squared) (at least for Re=0). The error also decreases with increasing Re at fixed core-to-ring radius ratio, and appears to be independent of Re as Re approaches infinity). Following a single ring, with Re=500, the vorticity contours indicate shedding of vorticity into the wake and a settling of an initially circular core to a more elliptical shape, similar to Norbury's steady inviscid vortices. Finally, we consider the case of leapfrogging vortex rings with Re=1000. The results show severe straining of the inner vortex core in the first pass and merging of the two cores during the second pass.

  10. Systematic Search for Rings around Kepler Planet Candidates: Constraints on Ring Size and Occurrence Rate

    Science.gov (United States)

    Aizawa, Masataka; Masuda, Kento; Kawahara, Hajime; Suto, Yasushi

    2018-05-01

    We perform a systematic search for rings around 168 Kepler planet candidates with sufficient signal-to-noise ratios that are selected from all of the short-cadence data. We fit ringed and ringless models to their light curves and compare the fitting results to search for the signatures of planetary rings. First, we identify 29 tentative systems, for which the ringed models exhibit statistically significant improvement over the ringless models. The light curves of those systems are individually examined, but we are not able to identify any candidate that indicates evidence for rings. In turn, we find several mechanisms of false positives that would produce ringlike signals, and the null detection enables us to place upper limits on the size of the rings. Furthermore, assuming the tidal alignment between axes of the planetary rings and orbits, we conclude that the occurrence rate of rings larger than twice the planetary radius is less than 15%. Even though the majority of our targets are short-period planets, our null detection provides statistical and quantitative constraints on largely uncertain theoretical models of the origin, formation, and evolution of planetary rings.

  11. 75 FR 77475 - Endangered and Threatened Species; Proposed Threatened Status for Subspecies of the Ringed Seal

    Science.gov (United States)

    2010-12-10

    ... underwent independent peer review by five scientists with expertise in ringed seal biology, Arctic sea ice... in the lee of ice hummocks. The seasonality of ice cover strongly influences ringed seal movements... sufficient for lair formation only where pressure ridges or ice hummocks cause the snow to form drifts at...

  12. Synthesis of Human Milk Oligosaccharides and Regioselective Ring Opening of Oxabicycles

    DEFF Research Database (Denmark)

    Jennum, Camilla Arboe

    . The tetrasaccharides were formed both by sequential and the developed one-pot method. Deprotection of the protecting group at the C-2-position on the galactose moiety liberated an acceptor for the fucosylation eventually creating the two linear pentasaccharides Lacto-N-fucopentaose I and Lacto-N-neofucopentaose I...... ligands. The ring opened iii products were similar to compounds, which had shown to be potential protein Bcl-XL antagonists, a target for future drugs in cancer treatment. The aim was to create a general asymmetric ring opening method of several enantiopure oxabicycles having different functional moieties...

  13. Molecular spectrum of laterally coupled quantum rings under intense terahertz radiation.

    Science.gov (United States)

    Baghramyan, Henrikh M; Barseghyan, Manuk G; Laroze, David

    2017-09-05

    We study the influence of intense THz laser radiation and electric field on molecular states of laterally coupled quantum rings. Laser radiation shows the capability to dissociate quantum ring molecule and add 2-fold degeneracy to the molecular states at the fixed value of the overlapping size between rings. It is shown that coupled to decoupled molecular states phase transition points form almost a straight line with a slope equal to two. In addition, the electric field direction dependent energy spectrum shows unexpected oscillations, demonstrating strong coupling between molecular states. Besides, intraband absorption is considered, showing both blue and redshifts in its spectrum. The obtained results can be useful for the controlling of degeneracy of the discrete energy spectrum of nanoscale structures and in the tunneling effects therein.

  14. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.

    2013-04-29

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting on a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, article 264506). These dynamics mainly occur within 50 -s after the first contact, requiring imaging at 1 million f.p.s. For a water drop impacting on a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Reynolds number Re above -12 000, up to 10 partial bubble rings have been observed at the base of the ejecta, starting when the contact is -20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into micro-bubbles. The different refractive index in the pool liquid reveals the destabilization of the vortices and the formation of streamwise vortices and intricate vortex tangles. Fine-scale axisymmetry is thereby destroyed. We show also that the shape of the drop has a strong influence on these dynamics. 2013 Cambridge University Press.

  15. Structure and dynamics of ringed galaxies

    International Nuclear Information System (INIS)

    Buta, R.J.

    1984-01-01

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

  16. Multiplicative Structure and Hecke Rings of Generator Matrices for Codes over Quotient Rings of Euclidean Domains

    Directory of Open Access Journals (Sweden)

    Hajime Matsui

    2017-12-01

    Full Text Available In this study, we consider codes over Euclidean domains modulo their ideals. In the first half of the study, we deal with arbitrary Euclidean domains. We show that the product of generator matrices of codes over the rings mod a and mod b produces generator matrices of all codes over the ring mod a b , i.e., this correspondence is onto. Moreover, we show that if a and b are coprime, then this correspondence is one-to-one, i.e., there exist unique codes over the rings mod a and mod b that produce any given code over the ring mod a b through the product of their generator matrices. In the second half of the study, we focus on the typical Euclidean domains such as the rational integer ring, one-variable polynomial rings, rings of Gaussian and Eisenstein integers, p-adic integer rings and rings of one-variable formal power series. We define the reduced generator matrices of codes over Euclidean domains modulo their ideals and show their uniqueness. Finally, we apply our theory of reduced generator matrices to the Hecke rings of matrices over these Euclidean domains.

  17. Investigation of an He-Ne laser generating a beam with a ring-shaped intensity distribution

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, I I; Troitskii, IU V; Iakushkin, S V

    1987-02-01

    The paper examines an He-Ne laser regime with the simultaneous generation of TEM(01) and TEM(10) modes, forming a beam with a ring-shaped intensity distribution with total suppression of the TEM(00) mode. The ratio of the intensity at the ring crest to the intensity at the axis reached a value of 200 and was limited by scattering in the optical components of the resonator. A regime of mutual frequency locking of the TEM(01) and TEM(10) modes was achieved with total spatial coherence of the ring-shaped beam. 14 references.

  18. Binomial Rings: Axiomatisation, Transfer and Classification

    OpenAIRE

    Xantcha, Qimh Richey

    2011-01-01

    Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.

  19. AN N-BODY INTEGRATOR FOR GRAVITATING PLANETARY RINGS, AND THE OUTER EDGE OF SATURN'S B RING

    International Nuclear Information System (INIS)

    Hahn, Joseph M.; Spitale, Joseph N.

    2013-01-01

    A new symplectic N-body integrator is introduced, one designed to calculate the global 360° evolution of a self-gravitating planetary ring that is in orbit about an oblate planet. This freely available code is called epi i nt, and it is distinct from other such codes in its use of streamlines to calculate the effects of ring self-gravity. The great advantage of this approach is that the perturbing forces arise from smooth wires of ring matter rather than discreet particles, so there is very little gravitational scattering and so only a modest number of particles are needed to simulate, say, the scalloped edge of a resonantly confined ring or the propagation of spiral density waves. The code is applied to the outer edge of Saturn's B ring, and a comparison of Cassini measurements of the ring's forced response to simulations of Mimas's resonant perturbations reveals that the B ring's surface density at its outer edge is σ 0 = 195 ± 60 g cm –2 , which, if the same everywhere across the ring, would mean that the B ring's mass is about 90% of Mimas's mass. Cassini observations show that the B ring-edge has several free normal modes, which are long-lived disturbances of the ring-edge that are not driven by any known satellite resonances. Although the mechanism that excites or sustains these normal modes is unknown, we can plant such a disturbance at a simulated ring's edge and find that these modes persist without any damping for more than ∼10 5 orbits or ∼100 yr despite the simulated ring's viscosity ν s = 100 cm 2 s –1 . These simulations also indicate that impulsive disturbances at a ring can excite long-lived normal modes, which suggests that an impact in the recent past by perhaps a cloud of cometary debris might have excited these disturbances, which are quite common to many of Saturn's sharp-edged rings

  20. Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

    Science.gov (United States)

    Buta, Ronald J.

    2017-11-01

    Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

  1. Dual RING E3 Architectures Regulate Multiubiquitination and Ubiquitin Chain Elongation by APC/C.

    Science.gov (United States)

    Brown, Nicholas G; VanderLinden, Ryan; Watson, Edmond R; Weissmann, Florian; Ordureau, Alban; Wu, Kuen-Phon; Zhang, Wei; Yu, Shanshan; Mercredi, Peter Y; Harrison, Joseph S; Davidson, Iain F; Qiao, Renping; Lu, Ying; Dube, Prakash; Brunner, Michael R; Grace, Christy R R; Miller, Darcie J; Haselbach, David; Jarvis, Marc A; Yamaguchi, Masaya; Yanishevski, David; Petzold, Georg; Sidhu, Sachdev S; Kuhlman, Brian; Kirschner, Marc W; Harper, J Wade; Peters, Jan-Michael; Stark, Holger; Schulman, Brenda A

    2016-06-02

    Protein ubiquitination involves E1, E2, and E3 trienzyme cascades. E2 and RING E3 enzymes often collaborate to first prime a substrate with a single ubiquitin (UB) and then achieve different forms of polyubiquitination: multiubiquitination of several sites and elongation of linkage-specific UB chains. Here, cryo-EM and biochemistry show that the human E3 anaphase-promoting complex/cyclosome (APC/C) and its two partner E2s, UBE2C (aka UBCH10) and UBE2S, adopt specialized catalytic architectures for these two distinct forms of polyubiquitination. The APC/C RING constrains UBE2C proximal to a substrate and simultaneously binds a substrate-linked UB to drive processive multiubiquitination. Alternatively, during UB chain elongation, the RING does not bind UBE2S but rather lures an evolving substrate-linked UB to UBE2S positioned through a cullin interaction to generate a Lys11-linked chain. Our findings define mechanisms of APC/C regulation, and establish principles by which specialized E3-E2-substrate-UB architectures control different forms of polyubiquitination. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Quantum Fourier Transform Over Galois Rings

    OpenAIRE

    Zhang, Yong

    2009-01-01

    Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...

  3. Verification of annual growth rings in Egyptian trees by C-14 method

    International Nuclear Information System (INIS)

    Belacy, N.; Abou El-Nour, F.; Jacoby, G.C.

    1990-01-01

    Annual growth rings in trees were thought to be due to sharp seasonal variations in the precipitation rates during the year. Accordingly temperature zone trees such as Egyptian trees were supposed to be away from this phenomenon. The temperature zones which are meant here are those of no sharp seasonal variations in the precipitation rates. The present study applied carbon-14 dating to prove that the growth rings in some Egyptian trees are annual. The method was based on the tropospheric measurements of C-14 during the period 1954-1981. C-14 exhibited a sharp peak resulting from the ever greater series of nuclear tests during 1963-1965. The presence of this peak for Egyptian trees proved that they form annual growth rings. (orig.) [de

  4. Parametric instability of spinning elastic rings excited by fluctuating space-fixed stiffnesses

    Science.gov (United States)

    Liu, Chunguang; Cooley, Christopher G.; Parker, Robert G.

    2017-07-01

    This study investigates the vibration of rotating elastic rings that are dynamically excited by an arbitrary number of space-fixed discrete stiffnesses with periodically fluctuating stiffnesses. The rotating, elastic ring is modeled using thin-ring theory with radial and tangential deformations. Primary and combination instability regions are determined in closed-form using the method of multiple scales. The ratio of peak-to-peak fluctuation to average discrete stiffness is used as the perturbation parameter, so the resulting perturbation analysis is not limited to small mean values of discrete stiffnesses. The natural frequencies and vibration modes are determined by discretizing the governing equations using Galerkin's method. Results are demonstrated for compliant gear applications. The perturbation results are validated by direct numerical integration of the equations of motion and Floquet theory. The bandwidths of the instability regions correlate with the fractional strain energy stored in the discrete stiffnesses. For rings with multiple discrete stiffnesses, the phase differences between them can eliminate large amplitude response under certain conditions.

  5. Novel manifestations of the Aharonov-Bohm effect in quantum rings and Moebius rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2013-01-01

    - An overview is given on the recent experimental and theoretical advancements in studies of novel manifestations of the Aharonov-Bohm quantum-interference effect for excitons confined to self assembled quantum rings and other semiconductor nanostructures with ring-like states of charge carriers as well as for electrons in Moebius rings at the micro- and nanoscale. The exciton Aharonov-Bohm effect can be effectively controlled by an out-of-plane magnetic field, a vertical electric field, a spin disorder. A 'delocalization-to-localization' transition for the electron ground state occurs in a Moebius ring as it is made more inhomogeneous. (authors)

  6. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

    2017-03-18

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  7. On P-coherent endomorphism rings

    Indian Academy of Sciences (India)

    A ring is called right -coherent if every principal right ideal is finitely presented. Let M R be a right -module. We study the -coherence of the endomorphism ring of M R . It is shown that is a right -coherent ring if and only if every endomorphism of M R has a pseudokernel in add M R ; S is a left -coherent ring if and ...

  8. Ab Initio Ligand Field Molecular Mechanics and the Nature of Metal-Ligand π-Bonding in Fe(II) 2,6-di(pyrazol-1-yl)pyridine Spin Crossover Complexes.

    Science.gov (United States)

    Deeth, Robert J; Halcrow, Malcolm A; Kershaw Cook, Laurence J; Raithby, Paul R

    2018-04-06

    A ligand field molecular mechanics (LFMM) force field has been constructed for the spin states of [Fe(bpp) 2 ] 2+ (bpp=2,6-di(pyrazol-1-yl)pyridine) and related complexes. A new charge scheme is employed which interpolates between partial charges for neutral bpp and protonated [H 3 bpp] 3+ to achieve a target metal charge. The LFMM angular overlap model (AOM) parameters are fitted to fully ab initio d orbital energies. However, several AOM parameter sets are possible. The ambiguity is resolved by calculating the Jahn-Teller distortion mode for high spin, which indicates that in [Fe(bpp) 2 ] 2+ pyridine is a π-acceptor and pyrazole a weak π-donor. The alternative fit, assumed previously, where both ligands act as π-donors leads to an inconsistent distortion. LFMM optimisations in the presence of [BF 4 ] - or [PF 6 ] - anions are in good agreement with experiment and the model also correctly predicts the spin state energetics for 3-pyrazolyl substituents where the interactions are mainly steric. However, for 4-pyridyl or 4-pyrazolyl substituents, LFMM only treats the electrostatic contribution which, for the pyridyl substituents, generates a fair correlation with the spin crossover transition temperatures, T 1/2 , but in the reverse sense to the dominant electronic effect. Thus, LFMM generates its smallest spin state energy difference for the substituent with the highest T 1/2 . One parameter set for all substituted bpp ligands is insufficient and further LFMM development will be required. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The new 3-(tert-butyl)-1-(2-nitrophenyl)-1H-pyrazol-5-amine: Experimental and computational studies

    Science.gov (United States)

    Cuenú, Fernando; Muñoz-Patiño, Natalia; Torres, John Eduard; Abonia, Rodrigo; Toscano, Rubén A.; Cobo, J.

    2017-11-01

    The molecular and supramolecular structure of the title compound, 3-(tertbutyl)-1-(2-nitrophenyl)-1H-pyrazol-5-amine (2NPz) from the single crystal X-ray diffraction (SC-XRD) and spectroscopic data analysis is reported. The computational analysis of the structure, geometry optimization, vibrational frequencies, nuclear magnetic resonance and UV-Vis is also described and compared with experimental data. Satisfactory theoretical aspects were made for the molecule using density functional theory (DFT), with B3LYP and B3PW91 functionals, and Hartree-Fock (HF), with 6-311++G(d,p) basis set, using GAUSSIAN 09 program package without any constraint on the geometry. With VEDA 4 software, vibrational frequencies were assigned in terms of the potential energy distribution while, with the GaussSum software, the percentage contribution of the frontier orbitals at each transition of the electronic absorption spectrum was established. The obtained results indicated that optimized geometry could well reflect the molecular structural parameters from SC-XRD. Theoretical data obtained for the vibrational analysis and NMR spectra are consistent with experimental data.

  10. Single-electron transfer in palladium complexes of 1,4-naphthoquinone-containing bis(pyrazol-1-yl)methane ligands.

    Science.gov (United States)

    Scheuermann, Sebastian; Sarkar, Biprajit; Bolte, Michael; Bats, Jan W; Lerner, Hans-Wolfram; Wagner, Matthias

    2009-10-05

    A 1,4-naphthoquinone-substituted bis(pyrazol-1-yl)methane ligand (N--N) has been synthesized and transformed into its corresponding Pd(II) chelate complex [(N--N)PdCl(2)]. Both N--N and [(N--N)PdCl(2)] have been fully characterized by NMR spectroscopy, spectro-electrochemistry, and X-ray crystallography. After treatment of [(N--N)PdCl(2)] with NEt(3), the signature of a 1,4-naphthosemiquinonate radical is visible in the UV-vis- and electron paramagnetic resonance (EPR) spectrum of the reaction mixture; the free ligand N--N does not react with NEt(3) under the conditions applied. It is therefore concluded that NEt(3) first reduces the Pd(II)-ion of [(N--N)PdCl(2)] to the zero-valent state and that this reaction is followed by a single-electron transfer from the metal atom to the 1,4-naphthoquinone moiety. The complex has been specifically designed to disfavor any direct Pd-to-naphthoquinone coordination. Electron transfer thus proceeds through space or, less likely, via sigma-bonds of the ligand framework.

  11. Multiphysics modelling of the spray forming process

    International Nuclear Information System (INIS)

    Mi, J.; Grant, P.S.; Fritsching, U.; Belkessam, O.; Garmendia, I.; Landaberea, A.

    2008-01-01

    An integrated, multiphysics numerical model has been developed through the joint efforts of the University of Oxford (UK), University of Bremen (Germany) and Inasmet (Spain) to simulate the spray forming process. The integrated model consisted of four sub-models: (1) an atomization model simulating the fragmentation of a continuous liquid metal stream into droplet spray during gas atomization; (2) a droplet spray model simulating the droplet spray mass and enthalpy evolution in the gas flow field prior to deposition; (3) a droplet deposition model simulating droplet deposition, splashing and re-deposition behavior and the resulting preform shape and heat flow; and (4) a porosity model simulating the porosity distribution inside a spray formed ring preform. The model has been validated against experiments of the spray forming of large diameter IN718 Ni superalloy rings. The modelled preform shape, surface temperature and final porosity distribution showed good agreement with experimental measurements

  12. BERKELEY: ALS ring

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-06-15

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  13. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

    The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

  14. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  15. On the Laurent polynomial rings

    International Nuclear Information System (INIS)

    Stefanescu, D.

    1985-02-01

    We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)

  16. The Hi-Ring DCN Architecture

    DEFF Research Database (Denmark)

    Galili, Michael; Kamchevska, Valerija; Ding, Yunhong

    2016-01-01

    We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization......We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization...

  17. The impact of exospheric neutral dynamics on ring current decay

    Science.gov (United States)

    Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.

    2015-12-01

    The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.

  18. Highly Efficient Spin-Current Operation in a Cu Nano-Ring

    Science.gov (United States)

    Murphy, Benedict A.; Vick, Andrew J.; Samiepour, Marjan; Hirohata, Atsufumi

    2016-11-01

    An all-metal lateral spin-valve structure has been fabricated with a medial Copper nano-ring to split the diffusive spin-current path. We have demonstrated significant modulation of the non-local signal by the application of a magnetic field gradient across the nano-ring, which is up to 30% more efficient than the conventional Hanle configuration at room temperature. This was achieved by passing a dc current through a current-carrying bar to provide a locally induced Ampère field. We have shown that in this manner a lateral spin-valve gains an additional functionality in the form of three-terminal gate operation for future spintronic logic.

  19. Strings, vortex rings, and modes of instability

    Directory of Open Access Journals (Sweden)

    Steven S. Gubser

    2015-03-01

    Full Text Available We treat string propagation and interaction in the presence of a background Neveu–Schwarz three-form field strength, suitable for describing vortex rings in a superfluid or low-viscosity normal fluid. A circular vortex ring exhibits instabilities which have been recognized for many years, but whose precise boundaries we determine for the first time analytically in the small core limit. Two circular vortices colliding head-on exhibit stronger instabilities which cause splitting into many small vortices at late times. We provide an approximate analytic treatment of these instabilities and show that the most unstable wavelength is parametrically larger than a dynamically generated length scale which in many hydrodynamic systems is close to the cutoff. We also summarize how the string construction we discuss can be derived from the Gross–Pitaevskii Lagrangian, and also how it compares to the action for giant gravitons.

  20. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

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

    Science.gov (United States)

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

    2013-11-01

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

  2. Liesegang rings in tissue. How to distinguish Liesegang rings from the giant kidney worm, Dioctophyma renale.

    Science.gov (United States)

    Tuur, S M; Nelson, A M; Gibson, D W; Neafie, R C; Johnson, F B; Mostofi, F K; Connor, D H

    1987-08-01

    Liesegang rings (LRs) are periodic precipitation zones from supersaturated solutions in colloidal systems. They are formed by a process that involves an interplay of diffusion, nucleation, flocculation or precipitation, and supersaturation. Examples include LRs of calcium carbonate in oölitic limestone (in nature), LRs of silver chromate in gelatin (in vitro), and LRs of glycoprotein in pulmonary corpora amylacea (in vivo). Here we describe LRs in lesions from 29 patients--mostly lesions of the kidney, synovium, conjunctiva, and eyelid. The LRs formed in cysts, or in fibrotic, inflamed, or necrotic tissue. The LRs in this study varied greatly in shape and size, measuring 7-800 microns. Special stains and energy-dispersive radiographic analysis or scanning electron microscopy revealed that some LRs contained calcium, iron (hemosiderin), silicon, and sulfur. Some pathologists have mistaken LRs for eggs, larvae, or adults of the giant kidney worm, Dioctophyma renale. D. renale is a large blood-red nematode that infects a variety of fish-eating mammals, especially mink. Fourteen documented infections of humans have been recorded, usually with adult worms expelled from the urethra. The adult worms are probably the largest helminth to parasitize humans. Eggs of D. renale are constant in size (60-80 microns X 39-47 microns), contain an embryo, and have characteristic sculpturing of the shell. Liesegang rings should not be mistaken for eggs, larvae, or adults of D. renale, or for any other helminth.

  3. Star-forming galaxy models: Blending star formation into TREESPH

    Science.gov (United States)

    Mihos, J. Christopher; Hernquist, Lars

    1994-01-01

    We have incorporated star-formation algorithms into a hybrid N-body/smoothed particle hydrodynamics code (TREESPH) in order to describe the star forming properties of disk galaxies over timescales of a few billion years. The models employ a Schmidt law of index n approximately 1.5 to calculate star-formation rates, and explicitly include the energy and metallicity feedback into the Interstellar Medium (ISM). Modeling the newly formed stellar population is achieved through the use of hybrid SPH/young star particles which gradually convert from gaseous to collisionless particles, avoiding the computational difficulties involved in creating new particles. The models are shown to reproduce well the star-forming properties of disk galaxies, such as the morphology, rate of star formation, and evolution of the global star-formation rate and disk gas content. As an example of the technique, we model an encounter between a disk galaxy and a small companion which gives rise to a ring galaxy reminiscent of the Cartwheel (AM 0035-35). The primary galaxy in this encounter experiences two phases of star forming activity: an initial period during the expansion of the ring, and a delayed phase as shocked material in the ring falls back into the central regions.

  4. Ground Movement in SSRL Ring

    International Nuclear Information System (INIS)

    Sunikumar, Nikita

    2011-01-01

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

  5. Ring Expansion and Rearrangements of Rhodium(II) Azavinyl Carbenes

    Science.gov (United States)

    Selander, Nicklas; Worrell, Brady T.

    2013-01-01

    An efficient, regioselective and convergent method for the ring expansion and rearrangement of 1-sulfonyl-1,2,3-triazoles under rhodium(II)-catalyzed conditions is described. These denitrogenative reactions form substituted enaminone and olefin-based products, which in the former case can be further functionalized to unique products rendering the sulfonyl triazole traceless. PMID:23161725

  6. Colliding and merging galaxies. II. S0 galaxies with polar rings

    International Nuclear Information System (INIS)

    Schweizer, F.; Whitmore, B.D.; Rubin, V.C.

    1983-01-01

    We first present a detailed optical study of A0136-0801, a 16 1/2 -mag ''spindle'' galaxy girdled by a ring of gas, dust, and young stars. The spindle is a normal S0 disk seen nearly edge-on, as shown by its photometric profile and fast rotation (v/sub rot//sigma/sub v/ = 2.2); a prolate structure seems to be ruled out. The surrounding ring runs over the poles of this S0 disk and serves as a probe of the vertical potential. The ring motions suggest that a massive halo extends far beyond the S0 disk (out to 3R 25 ) and that this halo is more nearly spherical than flat. We then list 22 related galaxies and derive that a few percent of all field S0's possess near-polar rings or disks. We suggest that these structures are due to a second event, most likely the transfer of mass from a companion galaxy during a close encounter and occasionally also the merger of a companion. Although accretion occurs presumably at random angles, polar rings are favored statistically because of their slow differential precession and consequent longevity. Alternate evolutionary schemes are also discussed. Finally, we suggest that M82 may be forming a polar ring from former M81 material, and predict that the ''tilted bulge'' of UGC 7576 is an S0 disk seen nearly edge-on

  7. Token ring technology report

    CERN Document Server

    2013-01-01

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

  8. MeV proton flux predictions near Saturn's D ring.

    Science.gov (United States)

    Kollmann, P; Roussos, E; Kotova, A; Cooper, J F; Mitchell, D G; Krupp, N; Paranicas, C

    2015-10-01

    Radiation belts of MeV protons have been observed just outward of Saturn's main rings. During the final stages of the mission, the Cassini spacecraft will pass through the gap between the main rings and the planet. Based on how the known radiation belts of Saturn are formed, it is expected that MeV protons will be present in this gap and also bounce through the tenuous D ring right outside the gap. At least one model has suggested that the intensity of MeV protons near the planet could be much larger than in the known belts. We model this inner radiation belt using a technique developed earlier to understand Saturn's known radiation belts. We find that the inner belt is very different from the outer belts in the sense that its intensity is limited by the densities of the D ring and Saturn's upper atmosphere, not by radial diffusion and satellite absorption. The atmospheric density is relatively well constrained by EUV occultations. Based on that we predict an intensity in the gap region that is well below that of the known belts. It is more difficult to do the same for the region magnetically connected to the D ring since its density is poorly constrained. We find that the intensity in this region can be comparable to the known belts. Such intensities pose no hazard to the mission since Cassini would only experience these fluxes on timescales of minutes but might affect scientific measurements by decreasing the signal-to-contamination ratio of instruments.

  9. Stochastic orbital migration of small bodies in Saturn's rings

    Science.gov (United States)

    Rein, H.; Papaloizou, J. C. B.

    2010-12-01

    Many small moonlets that create propeller structures have been found in Saturn's rings by the Cassini spacecraft. We study the dynamical evolution of such 20-50 m sized bodies, which are embedded in Saturn's rings. We estimate the importance of various interaction processes with the ring particles on the moonlet's eccentricity and semi-major axis analytically. For low ring surface densities, the main effects on the evolution of the eccentricity and the semi-major axis are found to be caused by collisions and the gravitational interaction with particles in the vicinity of the moonlet. For high surface densities, the gravitational interaction with self-gravity wakes becomes important. We also perform realistic three-dimensional, collisional N-body simulations with up to a quarter of a million particles. A new set of pseudo shear periodic boundary conditions is used, which reduces the computational costs by an order of magnitude compared to previous studies. Our analytic estimates are confirmed to within a factor of two. On short timescales the evolution is always dominated by stochastic effects caused by collisions and gravitational interaction with self-gravitating ring particles. These result in a random walk of the moonlet's semi-major axis. The eccentricity of the moonlet quickly reaches an equilibrium value owing to collisional damping. The average change in semi-major axis of the moonlet after 100 orbital periods is 10-100m. This translates to an offset in the azimuthal direction of several hundred kilometres. We expect that such a shift is easily observable. Two movies are only available in electronic form at http://www.aanda.org

  10. Optimizing ring-based CSR sources

    International Nuclear Information System (INIS)

    Byrd, J.M.; De Santis, S.; Hao, Z.; Martin, M.C.; Munson, D.V.; Li, D.; Nishimura, H.; Robin, D.S.; Sannibale, F.; Schlueter, R.D.; Schoenlein, R.; Jung, J.Y.; Venturini, M.; Wan, W.; Zholents, A.A.; Zolotorev, M.

    2004-01-01

    Coherent synchrotron radiation (CSR) is a fascinating phenomenon recently observed in electron storage rings and shows tremendous promise as a high power source of radiation at terahertz frequencies. However, because of the properties of the radiation and the electron beams needed to produce it, there are a number of interesting features of the storage ring that can be optimized for CSR. Furthermore, CSR has been observed in three distinct forms: as steady pulses from short bunches, bursts from growth of spontaneous modulations in high current bunches, and from micro modulations imposed on a bunch from laser slicing. These processes have their relative merits as sources and can be improved via the ring design. The terahertz (THz) and sub-THz region of the electromagnetic spectrum lies between the infrared and the microwave . This boundary region is beyond the normal reach of optical and electronic measurement techniques and sources associated with these better-known neighbors. Recent research has demonstrated a relatively high power source of THz radiation from electron storage rings: coherent synchrotron radiation (CSR). Besides offering high power, CSR enables broadband optical techniques to be extended to nearly the microwave region, and has inherently sub-picosecond pulses. As a result, new opportunities for scientific research and applications are enabled across a diverse array of disciplines: condensed matter physics, medicine, manufacturing, and space and defense industries. CSR will have a strong impact on THz imaging, spectroscopy, femtosecond dynamics, and driving novel non-linear processes. CSR is emitted by bunches of accelerated charged particles when the bunch length is shorter than the wavelength being emitted. When this criterion is met, all the particles emit in phase, and a single-cycle electromagnetic pulse results with an intensity proportional to the square of the number of particles in the bunch. It is this quadratic dependence that can

  11. Shield Optimization and Formulation of Regression Equations for Split-Ring Resonator

    Directory of Open Access Journals (Sweden)

    Tahir Ejaz

    2016-01-01

    Full Text Available Microwave resonators are widely used for numerous applications including communication, biomedical and chemical applications, material testing, and food grading. Split-ring resonators in both planar and nonplanar forms are a simple structure which has been in use for several decades. This type of resonator is characterized with low cost, ease of fabrication, moderate quality factor, low external noise interference, high stability, and so forth. Due to these attractive features and ease in handling, nonplanar form of structure has been utilized for material characterization in 1–5 GHz range. Resonant frequency and quality factor are two important parameters for determination of material properties utilizing perturbation theory. Shield made of conducting material is utilized to enclose split-ring resonator which enhances quality factor. This work presents a novel technique to develop shield around a predesigned nonplanar split-ring resonator to yield optimized quality factor. Based on this technique and statistical analysis regression equations have also been formulated for resonant frequency and quality factor which is a major outcome of this work. These equations quantify dependence of output parameters on various factors of shield made of different materials. Such analysis is instrumental in development of devices/designs where improved/optimum result is required.

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

    Science.gov (United States)

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

    2015-01-05

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

  13. Optimisation of spontaneous four-wave mixing in a ring microcavity

    Science.gov (United States)

    Chuprina, I. N.; An, P. P.; Zubkova, E. G.; Kovalyuk, V. V.; Kalachev, A. A.; Gol'tsman, G. N.

    2017-11-01

    A theory of spontaneous four-wave mixing in a ring microcavity is developed. The rate of emission of biphotons for pulsed and monochromatic pumping with allowance for the dispersion of group velocities is analytically calculated. In the first case, pulses in the form of an increasing exponential are considered, which are optimal for excitation of an individual resonator mode. The behaviour of the group velocity dispersion as a function of the width and height of the waveguide is studied for a specific case of a ring microcavity made of silicon nitride. The results of the numerical calculation are in good agreement with the experimental data. The ring microcavity is made of two types of waveguides: completely etched and half etched. It is found that the latter allow for better control over the parameters in the manufacturing process, making them more predictable. Presented at the Russian - British Symposium on Quantum Technologies (Moscow, 20 - 23 March 2017)

  14. Colloidal CdSe Quantum Rings.

    Science.gov (United States)

    Fedin, Igor; Talapin, Dmitri V

    2016-08-10

    Semiconductor quantum rings are of great fundamental interest because their non-trivial topology creates novel physical properties. At the same time, toroidal topology is difficult to achieve for colloidal nanocrystals and epitaxially grown semiconductor nanostructures. In this work, we introduce the synthesis of luminescent colloidal CdSe nanorings and nanostructures with double and triple toroidal topology. The nanorings form during controlled etching and rearrangement of two-dimensional nanoplatelets. We discuss a possible mechanism of the transformation of nanoplatelets into nanorings and potential utility of colloidal nanorings for magneto-optical (e.g., Aharonov-Bohm effect) and other applications.

  15. Polycomb Group Proteins RING1A and RING1B Regulate the Vegetative Phase Transition in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Jian Li

    2017-05-01

    Full Text Available Polycomb group (PcG protein-mediated gene silencing is a major regulatory mechanism in higher eukaryotes that affects gene expression at the transcriptional level. Here, we report that two conserved homologous PcG proteins, RING1A and RING1B (RING1A/B, are required for global H2A monoubiquitination (H2Aub in Arabidopsis. The mutation of RING1A/B increased the expression of members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL gene family and caused an early vegetative phase transition. The early vegetative phase transition observed in ring1a ring1b double mutant plants was dependent on an SPL family gene, and the H2Aub status of the chromatin at SPL locus was dependent on RING1A/B. Moreover, mutation in RING1A/B affected the miRNA156a-mediated vegetative phase transition, and RING1A/B and the AGO7-miR390-TAS3 pathway were found to additively regulate this transition in Arabidopsis. Together, our results demonstrate that RING1A/B regulates the vegetative phase transition in Arabidopsis through the repression of SPL family genes.

  16. Synthesis of first row transition metal carboxylate complexes by ring ...

    Indian Academy of Sciences (India)

    tion of pyromellitic dianhydride with methanol and ring opening of pyromellitic dianhydride takes place. The corresponding carboxylate complex formed dur- ing the process can be crystallised by adding biden- tate nitrogen donor ligands such as 1,10-phenanthroline or 2,2 - bipyridine.20 From the reaction with 1,10-.

  17. Researches on the Piston Ring

    Science.gov (United States)

    Ehihara, Keikiti

    1944-01-01

    In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

  18. 4-{(E-[2-(4-Iodobutoxybenzylidene]amino}-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-07-01

    Full Text Available The title Schiff base compound, C22H24IN3O2, adopts an E configuration about the central C=N bond. The pyrazolone ring makes a dihedral angle of 49.68 (10° with its attached phenyl ring. The phenolate plane makes dihedral angles of 16.78 (9 and 50.54 (9°, respectively, with the pyrazolone ring and the terminal phenyl ring. An intramolecular C—H...O hydrogen bond generates an S(6 ring motif. In the crystal structure, an intermolecular C—H...O hydrogen bond is also observed.

  19. Generation of stable mixed-compact-toroid rings by inducing plasma currents in strong E rings

    International Nuclear Information System (INIS)

    Jayakumar, R.; Taggart, D.P.; Parker, M.R.; Fleischmann, H.H.

    1989-01-01

    In the RECE-Christa device, hybrid-type compact toroid rings are generated by inducing large toroidal plasma currents I rho in strong electron rings using a thin induction coil positioned along the ring axis. Starting from field-reversal values δ ο = 50 - 120 percent of the original pure fast-electron ring, the induced plasma current I rho raises δ to a maximum value of up to 240 percent with I rho contributing more than 50 percent of the total ring current. Quite interestingly, the generated hybrid compact toroid configurations appear gross-stable during the full I rho pulse length (half-amplitude width about 100 μs)

  20. Magnetization of two coupled rings

    International Nuclear Information System (INIS)

    Avishai, Y; Luck, J M

    2009-01-01

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

  1. Magnetized jet creation using a ring laser and applications

    Science.gov (United States)

    Liang, Edison; Gao, Ian; Lu, Yingchao; Ji, Hantao; Follett, Russ; Froula, Dustin; Tzeferacos, Petros; Lamb, Donald; Bickel, Andrew; Sio, Hong; Li, Chi Kiang; Petrasso, Richard; Wei, Mingsheng; Fu, Wen; Han, Lily

    2017-10-01

    We have recently demonstrated a new robust platform of magnetized jet creation using 20 OMEGA beams to form a hollow ring. We will present the latest experimental results and their theoretical interpretation, and explore potential applications to laboratory astrophysics, fundamental plasma physics and other areas. We will also discuss the scaling of this platform to future NIF experiments.

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

    International Nuclear Information System (INIS)

    Chwiej, T; Szafran, B

    2013-01-01

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

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

    Science.gov (United States)

    Chwiej, T; Szafran, B

    2013-04-17

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

  4. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  5. Analytical model for double split ring resonators with arbitrary ring width

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Jensen, Thomas; Krozer, Viktor

    2008-01-01

    For the first time, the analytical model for a double split ring resonator with unequal width rings is developed. The proposed models for the resonators with equal and unequal widths are based on an impedance matrix representation and provide the prediction of performance in a wide frequency range...

  6. General Series Solutions for Stresses and Displacements in an Inner-fixed Ring

    Science.gov (United States)

    Jiao, Yongshu; Liu, Shuo; Qi, Dexuan

    2018-03-01

    The general series solution approach is provided to get the stress and displacement fields in the inner-fixed ring. After choosing an Airy stress function in series form, stresses are expressed by infinite coefficients. Displacements are obtained by integrating the geometric equations. For an inner-fixed ring, the arbitrary loads acting on outer edge are extended into two sets of Fourier series. The zero displacement boundary conditions on inner surface are utilized. Then the stress (and displacement) coefficients are expressed by loading coefficients. A numerical example shows the validity of this approach.

  7. Ring Resonator for Detection of Melting Brine Under Shallow Subsurface of Mars

    Science.gov (United States)

    Ponchak, George E.; Jordan, Jennifer L.; Scardelletti, Maximilian C.

    2016-01-01

    Laboratory experimental evidence using Raman spectroscopy has shown that liquid brine may form below the shallow subsurface of Mars. A simpler experimental method to verify the presence of liquid brine or liquid water below Mars surface is needed. In this paper, a ring resonator is used to detect the phase change between frozen water and liquid water below a sandy soil that simulates the Mars surface. Experimental data shows that the ring resonator can detect the melting of thin layers of frozen brine or water up to 15 mm below the surface.

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

    Science.gov (United States)

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

    2016-12-12

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

  9. Inhibition of the Ras-Net (Elk-3) pathway by a novel pyrazole that affects microtubules.

    Science.gov (United States)

    Wasylyk, Christine; Zheng, Hong; Castell, Christelle; Debussche, Laurent; Multon, Marie-Christine; Wasylyk, Bohdan

    2008-03-01

    Net (Elk-3/SAP-2/Erp) is a transcription factor that is phosphorylated and activated by the Ras-extracellular signal-regulated kinase (Erk) signaling pathway and is involved in wound healing, angiogenesis, and tumor growth. In a cell-based screen for small molecule inhibitors of Ras activation of Net transcriptional activity, we identified a novel pyrazole, XRP44X. XRP44X inhibits fibroblast growth factor 2 (FGF-2)-induced Net phosphorylation by the Ras-Erk signaling upstream from Ras. It also binds to the colchicine-binding site of tubulin, depolymerizes microtubules, stimulates cell membrane blebbing, and affects the morphology of the actin skeleton. Interestingly, Combretastin-A4, which produces similar effects on the cytoskeleton, also inhibits FGF-2 Ras-Net signaling. This differs from other classes of agents that target microtubules, which have either little effect (vincristine) or no effect (docetaxel and nocodazole) on the Ras-Net pathway. XRP44X inhibits various cellular properties, including cell growth, cell cycle progression, and aortal sprouting, similar to other molecules that bind to the tubulin colchicine site. XRP44X has the potentially interesting property of connecting two important pathways involved in cell transformation and may thereby represent an interesting class of molecules that could be developed for cancer treatment.

  10. Pure subrings of the rings

    International Nuclear Information System (INIS)

    Tsarev, Andrei V

    2009-01-01

    Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.

  11. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

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

  12. Quantum Entanglement and Projective Ring Geometry

    Directory of Open Access Journals (Sweden)

    Michel Planat

    2006-08-01

    Full Text Available The paper explores the basic geometrical properties of the observables characterizing two-qubit systems by employing a novel projective ring geometric approach. After introducing the basic facts about quantum complementarity and maximal quantum entanglement in such systems, we demonstrate that the 15 × 15 multiplication table of the associated four-dimensional matrices exhibits a so-far-unnoticed geometrical structure that can be regarded as three pencils of lines in the projective plane of order two. In one of the pencils, which we call the kernel, the observables on two lines share a base of Bell states. In the complement of the kernel, the eight vertices/observables are joined by twelve lines which form the edges of a cube. A substantial part of the paper is devoted to showing that the nature of this geometry has much to do with the structure of the projective lines defined over the rings that are the direct product of n copies of the Galois field GF(2, with n = 2, 3 and 4.

  13. Manipulation of vortex rings for flow control

    International Nuclear Information System (INIS)

    Toyoda, Kuniaki; Hiramoto, Riho

    2009-01-01

    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  14. The Rings of Saturn

    Science.gov (United States)

    Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

    2018-03-01

    One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

  15. Storage ring to investigate cold unidimensional atomic collisions

    International Nuclear Information System (INIS)

    Marcassa, L. G.; Caires, A. R. L.; Nascimento, V. A.; Dulieu, O.; Weiner, J.; Bagnato, V. S.

    2005-01-01

    In this paper we employ a circulating ring of trapped atoms, that we have named the atomotron, to study cold collisions. The atomotron is obtained from a conventional magneto-optical trap when the two pairs of normally retroreflecting Gaussian laser beams in the x-y plane are slightly offset. Circulating stable atomic orbits then form a racetrack geometry in this plane. The circulating atom flux behaves similarly to an atomic beam with an average tangential velocity much greater than the transverse components, and is therefore suitable for one-dimensional atomic collision studies. Using the atomotron, we have investigated the polarization dependence of ultracold photoassociation collisions between Rb atoms circulating in the racetrack. The ability to investigate collisions in ultracold circulating atomic rings reveals alignment and orientation properties that are averaged away in ordinary three-dimensional magneto-optical trap collision processes

  16. A short history of e+e- storage rings

    International Nuclear Information System (INIS)

    Perez-y-Jorba, J.

    A quick survey of the history of electron-positron colliding-beam physics is given. First, the main physical characteristics of storage rings are recalled and the kinematical and dynamical properties of e + e - annihilation reactions are described. Then an account is made of the most important results obtained in particle physics with e + e - colliding rings. With the first generation of machines at low energies, the precise study of the vector mesons and the form factors of pions and kaons was made. Then at intermediate energies came the astonishing result that the total cross-section was keeping much higher than previously expected. Last but not least, a new realm of physics was opened by the discovery of the new particles, of their decays to intermediate states, by the possible existence of heavy leptons and of charmed mesons

  17. Examination techniques for non-magnetic rings

    International Nuclear Information System (INIS)

    Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.

    1990-01-01

    Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement

  18. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  19. 1,1′-{1,4-Phenylene bis[3-(6-chloro-2-methyl-4-phenylquinolin-3-yl-4,5-dihydro-1H-pyrazole-5,1-diyl]}dibutan-1-one

    Directory of Open Access Journals (Sweden)

    Allaoua Kedjadja

    2015-10-01

    Full Text Available A new polycyclic compound, 1,1′-{1,4-phenylene bis[3-(6-chloro-2-methyl-4-phenylquinolin-3-yl-4,5-dihydro-1H-pyrazole-5,1-diyl]}dibutan-1-one (3 has been synthesized by cyclocondensation of (2E,2′E-1,1′-bis(6-chloro-2-methyl-4-phenylquinolin-3-yl-3,3′-(1,4-phenylenediprop-2-en-1-one (2 and hydrazine hydrate in butanoic acid. The structure of this compound was established by elemental analysis, 1H-NMR, 13C-NMR, mass and IR spectroscopy.

  20. Three-component synthesis of C2F5-substituted pyrazoles from C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes

    Directory of Open Access Journals (Sweden)

    Pavel K. Mykhailiuk

    2015-01-01

    Full Text Available A one-pot reaction between C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes gives C2F5-substituted pyrazoles in excellent yields. The transformation smoothly proceeds in dichloromethane/water, tolerates the presence of air, and requires no purification of products by column chromatography. Mechanistically, C2F5CH2NH2·HCl and NaNO2 react first in water to generate C2F5CHN2, that participates in a [3 + 2] cycloaddition with electron-deficient alkynes in dichloromethane.