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Sample records for pyrazole rings maximum

  1. 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.

  2. 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.

  3. [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].

  4. 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.

  5. 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.

  6. 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].

  7. 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.

  8. 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.

  9. 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°.

  10. 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.

  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. 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...

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

    Science.gov (United States)

    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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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].

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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].

  6. [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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 5-(4-Methoxyphenyl-4-methyl-1-phenyl-3-p-tolyl-1H-pyrazole

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    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.

  12. 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)

  13. 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...

  14. 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.

  15. 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.

  16. 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°.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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].

  9. 1-{3-[1-(Hydroxyiminoethyl]-4-methyl-1H-pyrazol-5-yl}ethanone

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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...

  19. 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...

  20. 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.

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

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    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.

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

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    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

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

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    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.

  4. 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.

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

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    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.

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

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    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.

  7. 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

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

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    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.

  9. 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.

  10. 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.

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

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    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.

  12. 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.

  13. 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.

  14. 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.

  15. Conifers in cold environments synchronize maximum growth rate of tree-ring formation with day length.

    Science.gov (United States)

    Rossi, Sergio; Deslauriers, Annie; Anfodillo, Tommaso; Morin, Hubert; Saracino, Antonio; Motta, Renzo; Borghetti, Marco

    2006-01-01

    Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote (A), x-axis placement (beta) and rate of change (kappa). A strong linear relationship was found between the constants beta and kappa for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter.

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. 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.

  1. Effects of the Maximum Luminance in a Medical-grade Liquid-crystal Display on the Recognition Time of a Test Pattern: Observer Performance Using Landolt Rings.

    Science.gov (United States)

    Doi, Yasuhiro; Matsuyama, Michinobu; Ikeda, Ryuji; Hashida, Masahiro

    2016-07-01

    This study was conducted to measure the recognition time of the test pattern and to investigate the effects of the maximum luminance in a medical-grade liquid-crystal display (LCD) on the recognition time. Landolt rings as signals of the test pattern were used with four random orientations, one on each of the eight gray-scale steps. Ten observers input the orientation of the gap on the Landolt rings using cursor keys on the keyboard. The recognition times were automatically measured from the display of the test pattern on the medical-grade LCD to the input of the orientation of the gap in the Landolt rings. The maximum luminance in this study was set to one of four values (100, 170, 250, and 400 cd/m(2)), for which the corresponding recognition times were measured. As a result, the average recognition times for each observer with maximum luminances of 100, 170, 250, and 400 cd/m(2) were found to be 3.96 to 7.12 s, 3.72 to 6.35 s, 3.53 to 5.97 s, and 3.37 to 5.98 s, respectively. The results indicate that the observer's recognition time is directly proportional to the luminance of the medical-grade LCD. Therefore, it is evident that the maximum luminance of the medical-grade LCD affects the test pattern recognition time.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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-

  8. 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

  9. 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.

  10. 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)

  11. 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).

  12. 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.

  13. 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.

  14. 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.

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

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    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. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. (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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  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. 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)

  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. 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.

  15. 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.

  16. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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)

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. 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].

  16. 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...

  17. 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)

  18. 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.

  19. Temperature reconstruction and volcanic eruption signal from tree-ring width and maximum latewood density over the past 304 years in the southeastern Tibetan Plateau.

    Science.gov (United States)

    Li, Mingqi; Huang, Lei; Yin, Zhi-Yong; Shao, Xuemei

    2017-11-01

    This study presents a 304-year mean July-October maximum temperature reconstruction for the southeastern Tibetan Plateau based on both tree-ring width and maximum latewood density data. The reconstruction explained 58% of the variance in July-October maximum temperature during the calibration period (1958-2005). On the decadal scale, we identified two prominent cold periods during AD 1801-1833 and 1961-2003 and two prominent warm periods during AD 1730-1800 and 1928-1960, which are consistent with other reconstructions from the nearby region. Based on the reconstructed temperature series and volcanic eruption chronology, we found that most extreme cold years were in good agreement with major volcanic eruptions, such as 1816 after the Tambora eruption in 1815. Also, clusters of volcanic eruptions probably made the 1810s the coldest decade in the past 300 years. Our results indicated that fingerprints of major volcanic eruptions can be found in the reconstructed temperature records, while the responses of regional climate to these eruption events varied in space and time in the southeastern Tibetan Plateau.

  20. 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%.

  1. 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.

  2. 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

  3. Virtual Exploration of the Ring Systems Chemical Universe.

    Science.gov (United States)

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

    2017-11-27

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

  4. 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.

  5. 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)

  6. 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.

  7. Localized persistent spin currents in defect-free quasiperiodic rings with Aharonov–Casher effect

    International Nuclear Information System (INIS)

    Qiu, R.Z.; Chen, C.H.; Cheng, Y.H.; Hsueh, W.J.

    2015-01-01

    We propose strongly localized persistent spin current in one-dimensional defect-free quasiperiodic Thue–Morse rings with Aharonov–Casher effect. The results show that the characteristics of these localized persistent currents depend not only on the radius filling factor, but also on the strength of the spin–orbit interaction. The maximum persistent spin currents in systems always appear in the ring near the middle position of the system array whether or not the Thue–Morse rings array is symmetrical. The magnitude of the persistent currents is proportional to the sharpness of the resonance peak, which is dependent on the bandwidth of the allowed band in the band structure. The maximum persistent spin currents also increase exponentially as the generation order of the system increases. - Highlights: • Strongly localized persistent spin current in quasiperiodic AC rings is proposed. • Localized persistent spin currents are much larger than those produced by traditional mesoscopic rings. • Characteristics of the localized persistent currents depend on the radius filling factor and SOI strength. • The maximum persistent current increases exponentially with the system order. • The magnitude of the persistent currents is related to the sharpness of the resonance

  8. Lattice design of HISTRAP: Heavy ion storage ring for atomic physics

    International Nuclear Information System (INIS)

    Lee, I.Y.; Martin, J.A.; McGrory, J.B.; Milner, W.T.; Olsen, D.K.; Young, G.R.

    1987-01-01

    HISTRAP, a Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, cool, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. This four-fold symmetrical ring has a maximum bending power of 2 Tm. It has achromatic bends and uses quadrupole triplets for focusing

  9. Synthesis of 2-arylidenebenzocycloalkanones containing N-donor heterocyclic rings

    Energy Technology Data Exchange (ETDEWEB)

    Sun, S.-W., E-mail: sunsw0819@163.com [Yuncheng University, Department of Applied Chemistry (China); Zhang, X., E-mail: zhangx@hit.edu.cn [Harbin Institute of Technology, Academy of Fundamental and Interdisciplinary Science (China); Wang, G.-F. [Yuncheng University, Department of Applied Chemistry (China)

    2016-12-15

    A series of 2-arylidenebenzocycloalkanones containing heterocyclic rings 1–8 were prepared and characterized by IR, {sup 1}H NMR and elemental analyses. X-ray diffraction study of 6 reveals that the cyclohexyl ring of the 3,4-dihydronaphthalen-1(2H)-one adopts a chair conformation with a maximum deviation of 0.547(3) Å and makes dihedral angles of 52.24(17)° and 11.23(16)°, respectively, with the benzene plane and the mean plane of the benzimidazole ring.

  10. Project of the compact superconducting storage ring Siberia-SM

    Energy Technology Data Exchange (ETDEWEB)

    Anashin, V V; Arbuzov, V S; Blinov, G A; Veshcherevich, V G; Vobly, P D; Gorniker, E I; Zinevich, N I; Zinin, E I; Zubkov, N I; Kiselev, V A; Kollerov, E P; Kulipanov, G N; Matveev, Yu G; Medvedko, A S; Mezentsev, N A; Morgunov, L G; Petrov, V M; Petrov, S P; Repkov, V V; Roenko, V A; Skrinsky, A N; Sukhanov, S V; Tokarev, Yu I; Trakhtenberg, E M [AN SSSR, Novosibirsk. Inst. Yadernoj Fiziki

    1989-10-10

    In the last decade researches dealing with the creation of technology for X-ray lithography and for appropriate production equipment have been performed in many countries. The basic aim of these works is to provide a mass production of inexpensive devices with submicron structures (0.7-0.1 {mu}m). Bringing X-ray lithographic technology into commercial practice necessitates to design and build a dedicated SR source for the electronic industry. The use of superconducting bending magnets with 40-70 kG field strength enables the storage ring circumference to be reduced by a factor of 2-5 and the injection energy by a factor of 3-4 as compared to the conventional designs of storage rings. In the present paper we consider a storage ring which was designed for a maximum energy of 600 MeV, with 60 kG field strength in its bending magnets and 10 m circumference. The critical SR wavelength is 8.6 A. The electrons are injected into the storage ring at 50-60 MeV and the maximum stored current is assumed to be equal to 0.3 A. (orig.).

  11. Tritium concentrations in tree ring cellulose

    International Nuclear Information System (INIS)

    Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

    1989-01-01

    Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

  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. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. State of development of CERN proton storage rings

    CERN Document Server

    Huber, H

    1973-01-01

    The storage rings are briefly described and the 'luminosity', meaning a standardised counting method, is stated for the energies available at the centre of gravity. The maximum of luminosity reached so far is compared with the maximum possible luminosity and the reasons for the discrepancy are discussed. An example shows graphs of luminosity and of the beams after completion of the storage process, as functions of time. (2 refs).

  19. 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.

  20. Lord of the Rings - Return of the King: Swift-XRT observations of dust scattering rings around V404 Cygni

    Science.gov (United States)

    Beardmore, A. P.; Willingale, R.; Kuulkers, E.; Altamirano, D.; Motta, S. E.; Osborne, J. P.; Page, K. L.; Sivakoff, G. R.

    2016-10-01

    On 2015 June 15, the black hole X-ray binary V404 Cygni went into outburst, exhibiting extreme X-ray variability which culminated in a final flare on June 26. Over the following days, the Swift-X-ray Telescope detected a series of bright rings, comprising five main components that expanded and faded with time, caused by X-rays scattered from the otherwise unobservable dust layers in the interstellar medium in the direction of the source. Simple geometrical modelling of the rings' angular evolution reveals that they have a common temporal origin, coincident with the final, brightest flare seen by INTEGRAL's JEM X-1, which reached a 3-10 keV flux of ˜25 Crab. The high quality of the data allows the dust properties and density distribution along the line of sight to the source to be estimated. Using the Rayleigh-Gans approximation for the dust scattering cross-section and a power-law distribution of grain sizes a, ∝ a-q, the average dust emission is well modelled by q = 3.90^{+0.09}_{-0.08} and maximum grain size of a_+ = 0.147^{+0.024}_{-0.004} { μ m}, though significant variations in q are seen between the rings. The recovered dust density distribution shows five peaks associated with the dense sheets responsible for the rings at distances ranging from 1.19 to 2.13 kpc, with thicknesses of ˜40-80 pc and a maximum density occurring at the location of the nearest sheet. We find a dust column density of Ndust ≈ (2.0-2.5) × 1011 cm-2, consistent with the optical extinction to the source. Comparison of the inner rings' azimuthal X-ray evolution with archival Wide-field Infrared Survey Explorer mid-IR data suggests that the second most distant ring follows the general IR emission trend, which increases in brightness towards the Galactic north side of the source.

  1. Comparing CTH simulations and experiments on explosively loaded rings

    Science.gov (United States)

    Braithwaite, C. H.; Aydelotte, Brady; Collins, Adam; Thadhani, Naresh; Williamson, David Martin

    2012-03-01

    A series of experiments were conducted on explosively loaded metallic rings for the purpose of studying fragmentation. In addition to the collection of fragments for analysis, the radial velocity of the expanding ring was measured with photon Doppler velocimetry (PDV) and the arrangement was imaged using high speed photography. Both the ring material and the material used as the explosive container were altered and the results compared with simulations performed in CTH. Good agreement was found between the simulations and the experiments. The maximum radial velocity attained was approximately 380 m/s, which was achieved through loading with a 5g PETN based charge.

  2. The Storage Ring Proton EDM Experiment

    Science.gov (United States)

    Semertzidis, Yannis; Storage Ring Proton EDM Collaboration

    2014-09-01

    The storage ring pEDM experiment utilizes an all-electric storage ring to store ~1011 longitudinally polarized protons simultaneously in clock-wise and counter-clock-wise directions for 103 seconds. The radial E-field acts on the proton EDM for the duration of the storage time to precess its spin in the vertical plane. The ring lattice is optimized to reduce intra-beam scattering, increase the statistical sensitivity and reduce the systematic errors of the method. The main systematic error is a net radial B-field integrated around the ring causing an EDM-like vertical spin precession. The counter-rotating beams sense this integrated field and are vertically shifted by an amount, which depends on the strength of the vertical focusing in the ring, thus creating a radial B-field. Modulating the vertical focusing at 10 kHz makes possible the detection of this radial B-field by a SQUID-magnetometer (SQUID-based BPM). For a total number of n SQUID-based BPMs distributed around the ring the effectiveness of the method is limited to the N = n /2 harmonic of the background radial B-field due to the Nyquist sampling theorem limit. This limitation establishes the requirement to reduce the maximum radial B-field to 0.1-1 nT everywhere around the ring by layers of mu-metal and aluminum vacuum tube. The metho's sensitivity is 10-29 e .cm , more than three orders of magnitude better than the present neutron EDM experimental limit, making it sensitive to SUSY-like new physics mass scale up to 300 TeV.

  3. The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy.

    Science.gov (United States)

    Schurmans, Céline; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Thérèse; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

    2015-04-10

    Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV and pregnancy have been elaborated. In contrast with the CVRs, multi-purpose vaginal rings will have to be used continuously. Women who continuously use a CVR will no longer have menses. Furthermore, some safety aspects of CVR use have never been studied in-depth in the past, such as the impact of the vaginal ring on the vaginal microbiota, biofilm formation and induction of inflammation. We studied acceptability and these novel aspects of safety in Rwandan women. Although significant progress has been made over the past decade, Rwanda still has a high unmet need for contraception (with 47% unplanned births) and a generalized HIV epidemic, and CVRs are not yet available. We will conduct an open label, single centre, randomized controlled trial. A total of 120 HIV-negative women will be randomized to intermittent CVR use (to allow menstruation) or continuous CVR use. Women will be followed for a maximum of 14 weeks. In parallel, we will conduct a qualitative study using in-depth interview and focus group discussion methodology. In addition to evaluating the safety and acceptability of intermittent and continuous CVR use in Rwandan women, we hope that our findings will inform the development of future multipurpose vaginal rings, will prepare Rwandan study populations for future clinical trials of multipurpose vaginal rings, and will pave the way for introduction of CVRs on African markets. Clinicaltrials.gov NCT01796613 . Registered 14 February 2013.

  4. 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...

  5. Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

    Directory of Open Access Journals (Sweden)

    Alberto Reyna

    2014-01-01

    Full Text Available This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction.

  6. Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

    Science.gov (United States)

    Reyna, Alberto; Panduro, Marco A.; Del Rio Bocio, Carlos

    2014-01-01

    This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction. PMID:24701150

  7. 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.

  8. Injection into the LNLS UVX electron storage ring

    International Nuclear Information System (INIS)

    Lin, Liu

    1991-01-01

    To inject the 1.15 GeV electron storage ring - UVX - a beam from a linear accelerator - MAIRA - is used. The electrons are injected and accumulated at low energy (100MeV) until the nominal current of 100 mA is reached and than are ramped to the nominal energy. A study on a conventional injection scheme has been carried out. Two injection modes are investigated: injection with the phase ellipse parameters matched and mismatched to the ring's acceptance. The mismatched mode is optimized to fit the maximum of the injected beam into the acceptance

  9. Beam-beam interaction in e+-e- storage rings

    International Nuclear Information System (INIS)

    Le Duff, J.

    1977-01-01

    Colliding beams in electron-positron storage rings are discussed with particular reference to the space charge forces occuring during beam-beam interactions and their effect on beam current and consequently machine performance (maximum luminosity). The first section deals with linear beam-beam effects and discussses linear tune shift; the second section considers non-linear beam-beam effects and the creation on non-linear resonances. The last section poses questions of the possibility of extrapolating present results to future machines and discusses optimization of storage ring performance. (B.D.)

  10. 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.

  11. Velocity space ring-plasma instability, magnetized, Part I: Theory

    International Nuclear Information System (INIS)

    Lee, J.K.; Birdsall, C.K.

    1979-01-01

    The interaction of magnetized monoenergetic ions (a ring in velocity space) with a homogeneous Maxwellian target plasma is studied numerically using linear Vlasov theory. The ring may be produced when an energetic beam is injected perpendicular to a uniform magnetic field. In addition to yielding the previously known results, the present study classifies this flute-like instability into three distinct regimes based on the beam density relative to the plasma density, where many features such as physical mechanisms, dispersion diagrams, and maximum growth rates are quite different. The effects of electron dynamics, plasma or ring thermal spread, the ratio of ω/sub p//ω/sub c/ for plasma ions, and electromagnetic modifications are also considered

  12. From bicycle chain ring shape to gear ratio: algorithm and examples.

    Science.gov (United States)

    van Soest, A J

    2014-01-03

    A simple model of the bicycle drive system with a non-circular front chain ring is proposed and an algorithm is devised for calculation of the corresponding Gear Ratio As a Function Of Crank Angle (GRAFOCA). It is shown that the true effective radius of the chain ring is always the perpendicular distance between the crank axis and the line through the chain segment between the chain ring and the cog. It is illustrated that the true effective radius of the chain ring at any crank angle may differ substantially from the maximum vertical distance between the crank axis and the chain ring circumference that is used as a proxy for the effective chain ring radius in several studies; in particular, the crank angle at which the effective chain ring radius is maximal as predicted from the latter approach may deviate by as much as 0.30 rad from the true value. The algorithm proposed may help in designing chain rings that achieve the desired GRAFOCA. © 2013 Published by Elsevier Ltd. All rights reserved.

  13. 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.

  14. 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

  15. 5-Bromo-2-[5-(4-nitrophenyl-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl]pyrimidine

    Directory of Open Access Journals (Sweden)

    B. Kalluraya

    2009-12-01

    Full Text Available In the title pyrazoline compound, C19H14BrN5O2, the essentially planar pyrazoline and pyrimidine rings [maximum deviations = 0.013 (1 and 0.009 (1 Å, respectively] are inclined slightly to one another, making a dihedral angle of 10.81 (10°. The nitrobenzene unit is almost perpendicular to the attached pyrazoline ring, as indicated by the dihedral angle of 84.61 (8°. In the crystal structure, intermolecular C—H...N contacts link the molecules into dimers in an antiparallel manner. These dimers are further linked into one-dimensional chains along the b axis via C—H...O contacts. The crystal structure is consolidated by three different intermolecular π–π interactions [range of centroid–centroid distances = 3.5160 (11–3.6912 (11 Å].

  16. 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.

  17. Modeling and analysis on ring-type piezoelectric transformers.

    Science.gov (United States)

    Ho, Shine-Tzong

    2007-11-01

    This paper presents an electromechanical model for a ring-type piezoelectric transformer (PT). To establish this model, vibration characteristics of the piezoelectric ring with free boundary conditions are analyzed in advance. Based on the vibration analysis of the piezoelectric ring, the operating frequency and vibration mode of the PT are chosen. Then, electromechanical equations of motion for the PT are derived based on Hamilton's principle, which can be used to simulate the coupled electromechanical system for the transformer. Such as voltage stepup ratio, input impedance, output impedance, input power, output power, and efficiency are calculated by the equations. The optimal load resistance and the maximum efficiency for the PT will be presented in this paper. Experiments also were conducted to verify the theoretical analysis, and a good agreement was obtained.

  18. 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].

  19. 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.

  20. Helicity conservation under quantum reconnection of vortex rings.

    Science.gov (United States)

    Zuccher, Simone; Ricca, Renzo L

    2015-12-01

    Here we show that under quantum reconnection, simulated by using the three-dimensional Gross-Pitaevskii equation, self-helicity of a system of two interacting vortex rings remains conserved. By resolving the fine structure of the vortex cores, we demonstrate that the total length of the vortex system reaches a maximum at the reconnection time, while both writhe helicity and twist helicity remain separately unchanged throughout the process. Self-helicity is computed by two independent methods, and topological information is based on the extraction and analysis of geometric quantities such as writhe, total torsion, and intrinsic twist of the reconnecting vortex rings.

  1. Design Issues of the Pre-Compression Rings of Iter

    Science.gov (United States)

    Knaster, J.; Baker, W.; Bettinali, L.; Jong, C.; Mallick, K.; Nardi, C.; Rajainmaki, H.; Rossi, P.; Semeraro, L.

    2010-04-01

    The pre-compression system is the keystone of ITER. A centripetal force of ˜30 MN will be applied at cryogenic conditions on top and bottom of each TF coil. It will prevent the `breathing effect' caused by the bursting forces occurring during plasma operation that would affect the machine design life of 30000 cycles. Different alternatives have been studied throughout the years. There are two major design requirements limiting the engineering possibilities: 1) the limited available space and 2) the need to hamper eddy currents flowing in the structures. Six unidirectionally wound glass-fibre composite rings (˜5 m diameter and ˜300 mm cross section) are the final design choice. The rings will withstand the maximum hoop stresses machine operation. The present paper summarizes the pre-compression ring R&D carried out during several years. In particular, we will address the composite choice and mechanical characterization, assessment of creep or stress relaxation phenomena, sub-sized rings testing and the optimal ring fabrication processes that have led to the present final design.

  2. 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.

  3. Small electrostatic storage rings; also for highly charged ions?

    International Nuclear Information System (INIS)

    Moeller, S.P.; Pedersen, U.V.

    2001-01-01

    Two years ago, a small electrostatic storage ring ELISA (electrostatic ion storage ring, Aarhus) was put into operation. The design of this small 7 m circumference ring was based on electrostatic deflection plates and quadrupoles. This is in contrast to the larger ion storage rings, which are based on magnetic focusing and deflection. The result is a small, relatively inexpensive, storage ring being able to store ions of any mass and any charge at low energy ( -11 mbar resulting in storage times of several tens of seconds for singly charged ions. The maximum number of singly charged ions that can be stored is a few 10 7 . Several experiments have already been performed in ELISA. These include lifetime studies of metastable ions and studies of fullerenes and metal-cluster ions. Lasers are also used for excitation of the circulating ions. Heating/cooling of the ring is possible. Cooling of the ring leads to significantly lower pressures, and correspondingly longer lifetimes. A change of the temperature of the vacuum chambers surrounding the ion beam also leads to a change of the spectrum of the black-body radiation, which has a significant influence on weakly bound negative ions. At the time of writing, at least two other electrostatic storage rings are being built, and more are planned. In the following, the electrostatic storage ring ELISA will be described, and results from some of the initial experiments demonstrating the performance will be shown. The relative merits of such a ring, as opposed to the larger magnetic rings and the smaller ion traps will be discussed. The potential for highly charged ions will be briefly mentioned. (orig.)

  4. 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.

  5. 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.

  6. 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.

  7. A Feeding Strategy in Inner L-Shape Ring Hot Rolling Process

    Directory of Open Access Journals (Sweden)

    Wen Meng

    2017-01-01

    Full Text Available In order to make the inner L-shape ring polling process with a closed die structure (ILRRCDS on the top and bottom of the driven roll stable, at first, this paper established the mathematical model for ILRRCDS. Then, the plastic penetration and biting-in conditions for ILRRCDS were deduced based on plain ring rolling theory. Moreover, a feeding strategy that can realize a constant growth of the ring’s outer radius was proposed and the reasonable value ranges of the feed rate of the mandrel were determined. The numerical simulation model for ILRRCDS is established based on ABAQUS software. Finally, the equivalent plastic strain (PEEQ and temperature distributions of rolled ring were obtained. The results indicated that the proposed feeding strategy can realize a stable ILRRCDS. At the end of ILRRCDS, the PEEQ at the inner radius surface of the ring is maximum, the PEEQ at the outer radius surface of the ring takes the second place, and the PEEQ at the middle part of ring is minimum. With the increase of rolling time, the higher temperature zone of the rolled ring gradually moves from the center part of the ring to the “inner corner zone” of the ring.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. HISTRAP proposal: heavy-ion storage ring for atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D K; Alton, G D; Datz, S; Dittner, P F; Dowling, D T; Haynes, D L; Hudson, E D; Johnson, J W; Lee, I Y; Lord, R S

    1987-04-01

    HISTRAP, Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charge very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 T m and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.

  14. 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.

  15. 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.

  16. 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.

  17. Gated-controlled electron pumping in connected quantum rings

    International Nuclear Information System (INIS)

    Lima, R.P.A.; Domínguez-Adame, F.

    2014-01-01

    We study the electronic transport across connected quantum rings attached to leads and subjected to time-harmonic side-gate voltages. Using the Floquet formalism, we calculate the net pumped current generated and controlled by the side-gate voltage. The control of the current is achieved by varying the phase shift between the two side-gate voltages as well as the Fermi energy. In particular, the maximum current is reached when the side-gate voltages are in quadrature. This new design based on connected quantum rings controlled without magnetic fields can be easily integrated in standard electronic devices. - Highlights: • We introduce and study a minimal setup to pump electrons through connected quantum rings. • Quantum pumping is achieved by time-harmonic side-gate voltages instead of the more conventional time-dependent magnetic fluxes. • Our new design could be easily integrated in standard electronic devices

  18. 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)

  19. 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.

  20. An electron undulating ring for VLSI lithography

    International Nuclear Information System (INIS)

    Tomimasu, T.; Mikado, T.; Noguchi, T.; Sugiyama, S.; Yamazaki, T.

    1985-01-01

    The development of the ETL storage ring ''TERAS'' as an undulating ring has been continued to achieve a wide area exposure of synchrotron radiation (SR) in VLSI lithography. Stable vertical and horizontal undulating motions of stored beams are demonstrated around a horizontal design orbit of TERAS, using two small steering magnets of which one is used for vertical undulating and another for horizontal one. Each steering magnet is inserted into one of the periodic configulation of guide field elements. As one of useful applications of undulaing electron beams, a vertically wide exposure of SR has been demonstrated in the SR lithography. The maximum vertical deviation from the design orbit nCcurs near the steering magnet. The maximum vertical tilt angle of the undulating beam near the nodes is about + or - 2mrad for a steering magnetic field of 50 gauss. Another proposal is for hith-intensity, uniform and wide exposure of SR from a wiggler installed in TERAS, using vertical and horizontal undulating motions of stored beams. A 1.4 m long permanent magnet wiggler has been installed for this purpose in this April

  1. Application of ring lasers to determine the directions to the poles of Earth's rotation

    International Nuclear Information System (INIS)

    Golyaev, Yu D; Kolbas, Yu Yu

    2012-01-01

    Application of a ring laser to determine the directions to the poles of Earth's rotation is considered. The maximum accuracy of determining the directions is calculated, physical and technical mechanisms that limit the accuracy are analysed, and the instrumental errors are estimated by the example of ring He — Ne lasers with Zeeman biasing. (laser applications and other topics in quantum electronics)

  2. 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.

  3. Evolution of the ring current during two geomagnetic storms

    International Nuclear Information System (INIS)

    Lui, A.T.Y.; McEntire, R.W.; Krimigis, S.M.

    1987-01-01

    The progressive developments in the radial profiles of the particle pressure, plasma beta, and electric currents of the storm time ring current are investigated with data from the medium energy particle analyzer on the AMPTE Charged Particle Explorer spacecraft. Measurements of ions from 25 keV to 1 MeV, which carry 70--85% of the energy density of the entire ring current population, are used in this work. Two geomagnetic storms in September of 1984 are selected and four traversals of the equatorial ring current region during the course of each storm are studied. It is shown that enhancements in the particle pressure occur initially in the outer region and reach the inner region in the late phase of the storm. Structures suggestive of multiple particle injections are seen in the pressure profile. The leading and trailing edges of the particle injection structures are associated, respectively, with the depressions and enhancements of the westward current densities of the ring current. Plasma beta occasionally increases to values of the order of 1 in some regions of the ring current from prestorm values of the order of 0.1 or less. It is also found that the location of the maximum ring current particle pressure can be several earth radii from where the most intense westward ring current flows. This is a consequence of the dominance of pressure gradient current over the current associated with the magnetic field line curvature and particle anisotropy. copyright American Geophysical Union 1987

  4. CESR-c Performance of a Wiggler-Dominated Storage Ring

    CERN Document Server

    Temnykh, Alexander

    2005-01-01

    CESR-c operates now as a Wiggler-Dominated Storage Ring extending the lowest operating energy to 1.5GeV/beam. To improve beam stability at low energy, 12 super-ferric wiggler magnets with total length of 15m and 2.1T maximum field were installed in the ring. They cause ~90% of total beam radiation lost and increase radiation damping rate by factor 10 from ~3 to 40 Hz. However, the field of the wiggler magnets not only initiates the radiation, but potentially affects beam dynamics. The latter was an issue of a great concern from the planning the CESR-c project. In this paper we describe general performance of CESR-c and report the results of an experimental study on some aspects of beam dynamics. Comparisons are made between the experimental data and the model prediction. We find that all parameters, which are critically dependent on wigglers, such as beam properties and ring nonlinearity, are in good agreement with those calculated from the model. This validates the ring and wiggler models and justifies our d...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Crossing geometry for Main Ring on Doubler collisions

    International Nuclear Information System (INIS)

    Diebold, R.

    1977-01-01

    There are two basic methods for bringing about Main Ring on Doubler collisions: the transposed, and kissing geometries. Examples of both are discussed assuming maximum momenta of 250 on 1000 GeV/c. The magnets required to bring the beams into small-angle collision are substantial in both cases. Detailed engineering work will be required to distinguish a substantial cost advantage of one geometry over the other

  11. 1-[5-(Anthracen-9-yl-3-(4-nitrophenyl-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one

    Directory of Open Access Journals (Sweden)

    Bao-Li Dong

    2011-02-01

    Full Text Available In the title compound, C25H19N3O3, steric repulsion between the methine H atom and one of the anthryl H atoms seems to be concomitant with the considerable distortion of the anthryl fragment from planarity. The side rings of the anthryl subtend an angle of 9.57 (8°, which is an extreme value among the known reliably determined structures. This angle correlates with the length of the bond by which the anthryl is attached to the rest of the molecule. In the anthryl fragment, the maximum deviation of one of the C atoms from the mean plane is 0.126 (3 Å and regards the carrier C atom involved in the repulsion between the anthryl and the methine H atoms. The interplanar angle between the pyrazoline ring and the anthryl fragment is 88.36 (5° and that between the pyrazoline and 4-nitrophenyl rings is 8.80 (15°. Weak intermolecular C—H...N, C—H...π and π–π interactions [centroid–centroid distances of 3.7659 (17, 3.9477 (15 and 3.8972 (15 Å] are pesent in the structure.

  12. High-energy terahertz wave parametric oscillator with a surface-emitted ring-cavity configuration.

    Science.gov (United States)

    Yang, Zhen; Wang, Yuye; Xu, Degang; Xu, Wentao; Duan, Pan; Yan, Chao; Tang, Longhuang; Yao, Jianquan

    2016-05-15

    A surface-emitted ring-cavity terahertz (THz) wave parametric oscillator has been demonstrated for high-energy THz output and fast frequency tuning in a wide frequency range. Through the special optical design with a galvano-optical scanner and four-mirror ring-cavity structure, the maximum THz wave output energy of 12.9 μJ/pulse is achieved at 1.359 THz under the pump energy of 172.8 mJ. The fast THz frequency tuning in the range of 0.7-2.8 THz can be accessed with the step response of 600 μs. Moreover, the maximum THz wave output energy from this configuration is 3.29 times as large as that obtained from the conventional surface-emitted THz wave parametric oscillator with the same experimental conditions.

  13. 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

  14. Characterization of the International Linear Collider damping ring optics

    Science.gov (United States)

    Shanks, J.; Rubin, D. L.; Sagan, D.

    2014-10-01

    A method is presented for characterizing the emittance dilution and dynamic aperture for an arbitrary closed lattice that includes guide field magnet errors, multipole errors and misalignments. This method, developed and tested at the Cornell Electron Storage Ring Test Accelerator (CesrTA), has been applied to the damping ring lattice for the International Linear Collider (ILC). The effectiveness of beam based emittance tuning is limited by beam position monitor (BPM) measurement errors, number of corrector magnets and their placement, and correction algorithm. The specifications for damping ring magnet alignment, multipole errors, number of BPMs, and precision in BPM measurements are shown to be consistent with the required emittances and dynamic aperture. The methodology is then used to determine the minimum number of position monitors that is required to achieve the emittance targets, and how that minimum depends on the location of the BPMs. Similarly, the maximum tolerable multipole errors are evaluated. Finally, the robustness of each BPM configuration with respect to random failures is explored.

  15. Optical line shape of molecular rings: Influence of correlated nondiagonal disorder

    International Nuclear Information System (INIS)

    Barvik, I.; Warns, Ch.; Reineker, P.

    2006-01-01

    We investigate the optical properties of molecular rings which are generally influenced by many kinds of static disorder. Recently, Papiz suggested that quasistatic disorder, anticorrelated between neighboring transfer integrals, plays an important role. We simulate such a disorder by slow colored dichotomic Markov processes with long-time constants for the decay of their correlation functions. The colored dichotomic Markov processes leading to transfer integral fluctuations can be uncorrelated, anticorrelated or partially correlated between nearest neighboring transfer integrals in the ring. The optical line shape of the molecular ring is modeled and investigated in dependence on the parameters of the stochastic processes. Conclusions as regards the influence of the correlation on the splitting of the optical line shape, the shift of the optical absorption maximum and the width of the optical line are drawn

  16. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

    During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

  17. Modified climate with long term memory in tree ring proxies

    Czech Academy of Sciences Publication Activity Database

    Zhang, H.; Yuan, N.; Esper, J.; Werner, J. P.; Xoplaki, E.; Büntgen, Ulf; Treydte, K.; Luterbacher, J.

    2015-01-01

    Roč. 10, č. 8 (2015), č. článku 084020. ISSN 1748-9326 Institutional support: RVO:67179843 Keywords : surface-temperature * northern-hemisphere * china * variability * persistence * precipitation * fluctuations * millennium * rainfall * model * climate reconstructions * tree-ring width * maximum latewood density * frequency domains Subject RIV: EH - Ecology, Behaviour Impact factor: 4.134, year: 2015

  18. 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.

  19. (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.

  20. 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)

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Use of a ring-shaped, passively stable, superconducting magnetic bearing in the ring spinning process; Einsatz eines ringfoermigen, passiv stabilen, supraleitenden Magnetlagers im Ringspinnprozess

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Anne; Sparing, Maria; Berger, Dietmar; Fuchs, Guenter; Schultz, Ludwig [IFW Dresden (Germany). Inst. fuer Metallische Werkstoffe; Hossain, Mahmud; Abdkader, Anwar; Cherif, Chokri [TU Dresden (Germany). ITM

    2015-07-01

    For the integration of a superconducting magnetic bearing in a ring spinning machine a LN{sub 2} continuous flow cryostat was developed, which is needed to cool the superconductor below its transition temperature of ∝91 K and simultaneously ensures that the spinning process takes place at room temperature. The ring spinning process is the most widely used process for spinning yarn. In this case, a loose fiber connection is first stretched in a roller system, then twisted by the so-called spinning ring-ring traveler system, and finally wound on a spindle. The spinning ring is a circular guide, which is mounted around the spindle. On this the ring traveler rotates as yarn guide. The yarn is driven by the rotation of the spindle and there is a balloon-shaped movement of the yarn which results the twist. The productivity of the process is limited by the systematic frictional heat between the yarn, spinning ring and ring travelers. This leads at high speeds to yarn breakage and limits the maximum spindle speed depending on the type of fiber to a maximum of 25,000 U/min. To increase the speed and thus the productivity of the process, the conventional spinning ring-ring rotor system is replaced by a superconducting magnetic bearing. Here floats a NdFeB permanent magnet passively stable over the LN{sub 2} cooled ceramic high-temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x}. Driven by the yarn the permanent magnet rotates, thus ensuring the necessary balloon-shaped yarn movement to twist. Such a bearing has been successfully tested in a ring spinning machine. Preliminary results show a similar yarn quality. [German] Fuer die Integration eines supraleitenden Magnetlagers in eine Ringspinnmaschine wurde ein LN{sub 2}-Durchflusskryostat entwickelt, der noetig ist, um den Supraleiter unter seine Sprungtemperatur von ∝91 K zu kuehlen und gleichzeitig dafuer sorgt, dass der Spinnprozess bei Raumtemperatur ablaeuft. Der Ringspinnprozess ist der am weitesten verbreitete

  7. 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)

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Undulator tunability and synchrotron ring-energy

    International Nuclear Information System (INIS)

    Viccaro, P.J.; Sheony, G.K.

    1992-01-01

    An undulator has two properties which make it an extremely attractive source of electromagnetic radiation. The first is that the radiation is concentrated in a number of narrow energy bands known as harmonics of the device. The second characteristic is that under favorable operating conditions, the energy of these harmonics can be shifted or open-quote tunedclose quotes over an energy interval which can be as large as two or three times the value of the lowest energy harmonic. Both the photon energy of an undulator as well as its tunability are determined by the period, λ, of the device, the magnetic gap, G (which is larger than the minimum aperture required for injection and operation of the storage ring) and the storage ring energy E R . Given the photon energy, E p , the above parameters ultimately define the limits of operation or tunability of the undulator. In general, the larger the tunability range, the more useful the device. Therefore, for a given required maximum photon energy, it is desirable to find the operating conditions and device parameters which result in the largest tunability interval possible. With this in mind, we have investigated the question of undulator tunability with emphasis on the role of the ring energy in order to find the smallest E R consistent with the desired tunability interval and photon energy. As a guideline, we have included a preliminary criteria, concerning the tunability requirements for the Advanced Photon Source (APS) to be built at Argonne. The analysis is aimed at X-ray undulator sources on the APS but is applicable to any storage ring

  15. 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 ...

  16. 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

  17. Ring cavity surface emitting semiconductor lasers

    International Nuclear Information System (INIS)

    Mujagic, E.

    2010-01-01

    m. Characterizations indicate a high temperature operation of MIR ring-CSELs along with a reduction in threshold current density of MIR devices by 35% as compared to Fabry-Perot devices. The lower operating currents in ring-CSELs became noticeable in continuous wave (CW) operation with a 50K higher maximum temperature than in FP lasers. A two-fold enhancement in radiation efficiency was obtained in MIR and THz ring-CSELs as compared to FP emitters. The DFB grating on top of the resonator gives rise to a single-mode operation of ring-CSELs for all operation currents. Linear wavelength tuning is achieved by fabricating different gratings periods as well as by a variation in temperature. The slope efficiency and the threshold current density does not seem to significantly depend on the grating period, which is attributed to the absence of mirrors. The incorporated circular waveguide geometry along with the surface emitting character gives rise to symmetric and low divergence azimuthally polarized optical beams. The recorded far-fields indicate a ring shaped interference patterns with lobe separations of 1.34 o and 14.14 o for MIR and THz ring-CSELs, respectively. Fabrication of detuned gratings led to a grating period induced as well as to a tunable wavelength induced beam shaping, with beam patterns ranging from spot to wide ring cross sections. (author) [de

  18. 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.

  19. 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.

  20. 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

  1. Design analysis of a self-acting spiral-groove ring seal for counter-rotating shafts. [o ring seals

    Science.gov (United States)

    Dirusso, E.

    1983-01-01

    A self-acting spiral groove inter-shaft ring seal of nominal 16.33 cm (6.43 in.) diameter for sealing fan bleed air between counter rotating shafts in advanced turbofan engines was analyzed. The analysis focused on the lift force characteristics of the spiral grooves. A NASA Lewis developed computer program for predicting the performance of gas lubricated face seals was used to optimize the spiral groove geometry to produce maximum lift force. Load capacity curves (lift force as function of film thickness) were generated for four advanced turbofan engine operating conditions at relative seal speeds ranging from 17,850 to 29,800 rpm, sealed air pressures from 6 to 42 N/sq cm (9 to 60 psi) absolute and temperatures from 95 to 327 C (203 to 620 F). The relative seal sliding speed range was 152 to 255 m/sec (500 to 836 ft/sec). The analysis showed that the spiral grooves are capable of producing sufficient lift force such that the ring seal will operate in a noncontacting mode over the operating range of typical advanced turbofan engines.

  2. Experimental investigation on sandwich structure ring-type ultrasonic motor.

    Science.gov (United States)

    Peng, Taijiang; Shi, Hongyan; Liang, Xiong; Luo, Feng; Wu, Xiaoyu

    2015-02-01

    This paper presents a manufacture method for a sandwich structure Ultrasonic Motor (USM) and experiment. Two pieces of rotor clamped on a stator, and a stainless steel disk-spring is bonded on the hollow rotor disk to provide the press by a nut assembled on the shaft. The stator is made of a double-side Printed-Circuit Board (PCB) which is sawed out the ring in the center and connected on the board with three legs. On each side of the ring surface, there are electrodes connected at the same position via through hole. The three layer drive circuit for sine, cosine, and ground signal is connected on the board through each leg. There are many piezoelectric components (PZT) bonded between two electrodes and fill soldering tin on each electrode. Then PZT is welded on PCB by reflow soldering. Finally, rub the gibbous soldering tin down to the position of PZT surface makes sure the surface contacts with rotor evenly. The welding process can also be completed by Surface Mounted Technology (SMT). A prototype motor is manufactured by this method. Two B03 model shapes of the stator are obtained by the finite element analysis and the optimal frequency of the motor is 56.375 kHz measured by impedance instrument. The theoretical analysis is conducted for the relationship between the revolving speed of the USM and thickness of stator ring, number of the travelling waves, PZT amplitude, frequency and the other parameters. The experiment result shows that the maximum revolving speed is 116 RPM and the maximum torque is 25 N mm, when the actuate voltage is 200 VAC. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The Effect of Uniform Background Flow on Vortex Ring Formation and Pinch-off

    Science.gov (United States)

    Krueger, Paul S.; Dabiri, John O.; Gharib, Morteza

    2002-11-01

    Experimental investigations of vortex ring formation are extended to include the effects of a uniform background flow, in a manner relevant to the locomotion of aquatic animals utilizing jet propulsion. Gharib et. al. [J. Fluid Mech. 360, 121 (1998)] generated vortex rings using a piston/cylinder apparatus with relatively large discharge times to demonstrate that the vortex ring at the leading edge of the jet attains its maximum circulation at a piston stroke-to-diameter ratio L/D of 4. This "formation number" is robust over a range of piston motions and cylinder boundary conditions, and can be explained in terms of the Kelvin-Benjamin variational principle. To determine the effect of background flow on formation number and pinch-off of the leading vortex ring, uniform co-flow is established in a large annulus surrounding the vortex generator. The ratio of co-flow velocity to piston velocity is varied between 0 and 1. In addition, the co-flow is initiated at times both before and after the start of vortex ring formation. We present results for stroke ratios L/D = 2 and L/D = 8, in order to discern effects of the co-flow on the leading vortex ring in isolation and in the presence of a trailing jet.

  4. 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.

  5. 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

  6. 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.

  7. Many missing rings in old Canary pines can be related with age, fires and traditional uses

    Energy Technology Data Exchange (ETDEWEB)

    Génova, M.; Santana, C.; Martínez, B.

    2017-11-01

    Aim and area of study: In the present paper we estimated the age of four monumental Pinus canariensis of Gran Canaria (Canary Islands, Spain) by means of tree-ring analysis. Many tree-ring series have been accurately studied and many missing rings have been determined. Material and methods: The trees were dead and the samples analysed were big disks. We measured numerous radii and crossdated the individual tree-ring series, paying particular attention to the existence and location of missing rings. We have distinguished between missing outer rings (MORs) and missing inner rings (MIRs) and analysed the possible causes of both. Main results: We determined an average of 8.8% total missing rings (MRs) for these long-lived trees, with a maximum of 96 MRs in a series of over 500. We have tried to establish a tree-ring chronology on Gran Canaria Island, also having the tree-ring series from Inagua site, but the long individual tree-ring series analysed do not crossdate between them. Research highlights: We consider the Canary pine a species hard to conducting dendroecological studies, especially if the samples come from managed old trees, in which a large amount of known and potentially unknown missing rings can hampered dating. Even knowing the difficulties involved in dendrochronological analyses of P. canariensis, we can confirm that it is a long-lived species, which can grow to over 500 years, and some of whose growth changes could be associated with certain historical and ecological events.

  8. Many missing rings in old Canary pines can be related with age, fires and traditional uses

    International Nuclear Information System (INIS)

    Génova, M.; Santana, C.; Martínez, B.

    2017-01-01

    Aim and area of study: In the present paper we estimated the age of four monumental Pinus canariensis of Gran Canaria (Canary Islands, Spain) by means of tree-ring analysis. Many tree-ring series have been accurately studied and many missing rings have been determined. Material and methods: The trees were dead and the samples analysed were big disks. We measured numerous radii and crossdated the individual tree-ring series, paying particular attention to the existence and location of missing rings. We have distinguished between missing outer rings (MORs) and missing inner rings (MIRs) and analysed the possible causes of both. Main results: We determined an average of 8.8% total missing rings (MRs) for these long-lived trees, with a maximum of 96 MRs in a series of over 500. We have tried to establish a tree-ring chronology on Gran Canaria Island, also having the tree-ring series from Inagua site, but the long individual tree-ring series analysed do not crossdate between them. Research highlights: We consider the Canary pine a species hard to conducting dendroecological studies, especially if the samples come from managed old trees, in which a large amount of known and potentially unknown missing rings can hampered dating. Even knowing the difficulties involved in dendrochronological analyses of P. canariensis, we can confirm that it is a long-lived species, which can grow to over 500 years, and some of whose growth changes could be associated with certain historical and ecological events

  9. 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

  10. Photon-induced tunability of the thermospin current in a Rashba ring

    Science.gov (United States)

    Abdullah, Nzar Rauf; Arnold, Thorsten; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar

    2018-04-01

    The goal of this work is to show how the thermospin polarization current in a quantum ring changes in the presence of Rashba spin-orbit coupling and a quantized single photon mode of a cavity the ring is placed in. Employing the reduced density operator and a general master equation formalism, we find that both the Rashba interaction and the photon field can significantly modulate the spin polarization and the thermospin polarization current. Tuning the Rashba coupling constant, degenerate energy levels are formed corresponding to the Aharonov-Casher destructive phase interference in the quantum ring system. Our analysis indicates that the maximum spin polarization can be observed at the points of degenerate energy levels due to spin accumulation in the system without the photon field. The thermospin current is thus suppressed. In the presence of the cavity, the photon field leads to an additional kinetic momentum of the electron. As a result the spin polarization can be enhanced by the photon field.

  11. Characteristics of hot electron ring in a simple magnetic mirror field

    International Nuclear Information System (INIS)

    Hosokawa, M.; Ikegami, H.

    1980-12-01

    Characteristics of hot electron ring are studied in a simple magnetic mirror machine (mirror ratio 2 : 1) with a diameter of 30 cm at the midplane and with the distance of 80 cm between the mirrors. Maximum microwave input power is 5 kW at 6.4 GHz with the corresponding power density of approximately 0.3 W/cm 3 . With a background cold plasma of 4 x 10 11 cm -3 , hot electron rings are most effectively generated in two cases when the magnetic field on the axis of the midplane is set near the fundamental or the second harmonic electron cyclotron resonance to the applied microwave frequency. Density profile of the hot electrons is observed to take a so-called ring shape with a radius controllable by the magnetic field intensity and with an axial length of approximately 10 cm. The radial cut view of the ring, however, indicates an M shape density profile, and the density of the hot electrons on the axis is about one half of the density at the ring. Approximately 30 msec is needed before generating the hot electron ring at the density of 10 10 cm -3 with an average kinetic energy of 100 keV. The ultimate energy distribution function is observed to have a stepwise cut in the high energy tail and no energetic components above 1 MeV are detected. The hot electron ring is susceptible to a few instabilities which can be artificially triggered. One of the instabilities is observed to associate with a loss of lower energetic electrons and microwave bursts. At the instability, the ring shape is observed to transform into a filled cylinder in a few microseconds and disappear. (author)

  12. 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.

  13. Modifications to the application of pressure to a quarter of the circumference of panel rings (tests 54 and 55)

    Energy Technology Data Exchange (ETDEWEB)

    Van Duyse, H [INIEX

    1978-01-01

    Tests 54 and 55 were carried out on rings made up of the usual type of panel. Test 54 involved panels manufactured at Zolder and Test 55 involved those manufactured at Beringen. Both types of ring are 20 cm thick, 64 cm wide and have an internal diameter of 4.20 m. The tests involved application of pressure to one quarter of the circumference, the remainder of the ring being subject to restraint against the steel testing frame. Timber chocks were inserted between the ring and the frame. The reinforcements tested were those used with the normal type of panel. An account of deformation of the ring, cracking of the panels, and deformation of the concrete is given. Tables and figures summarizing the results achieved are included. Maximum load prior to breaking was 292 t in the case of the Zolder ring and 293 t in the case of the Beringen ring; initial cracking occurred at 35 and 30 t, respectively. (In French and in Dutch)

  14. 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- ...

  15. Optimal multiple-information integration inherent in a ring neural network

    International Nuclear Information System (INIS)

    Takiyama, Ken

    2017-01-01

    Although several behavioral experiments have suggested that our neural system integrates multiple sources of information based on the certainty of each type of information in the manner of maximum-likelihood estimation, it is unclear how the maximum-likelihood estimation is implemented in our neural system. Here, I investigate the relationship between maximum-likelihood estimation and a widely used ring-type neural network model that is used as a model of visual, motor, or prefrontal cortices. Without any approximation or ansatz, I analytically demonstrate that the equilibrium of an order parameter in the neural network model exactly corresponds to the maximum-likelihood estimation when the strength of the symmetrical recurrent synaptic connectivity within a neural population is appropriately stronger than that of asymmetrical connectivity, that of local and external inputs, and that of symmetrical or asymmetrical connectivity between different neural populations. In this case, strengths of local and external inputs or those of symmetrical connectivity between different neural populations exactly correspond to the input certainty in maximum-likelihood estimation. Thus, my analysis suggests appropriately strong symmetrical recurrent connectivity as a possible candidate for implementing the maximum-likelihood estimation within our neural system. (paper)

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

    Science.gov (United States)

    Vincent, Alan

    1996-10-01

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

  17. 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

  18. Pooled versus separate tree-ring δD measurements, and implications for reconstruction of the Arctic Oscillation in northwestern China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaohong, E-mail: liuxh@lzb.ac.cn [State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 (China); An, Wenling [MOE, Key Laboratory for Coast and Island Development, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093 (China); Treydte, Kerstin [Swiss Federal Research Institute WSL, Dendro Sciences Unit, Zürcherstrasse 111, CH-8903 Birmensdorf (Switzerland); Wang, Wenzhi; Xu, Guobao; Zeng, Xiaomin; Wu, Guoju; Wang, Bo; Zhang, Xuanwen [State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2015-04-01

    Stable hydrogen isotope ratios (δD) in tree rings are an attractive but still rarely explored terrestrial archive of past climatic information. Because the preparation of the cellulose nitrate for δD measurements requires more wood and a longer preparation time than preparation techniques for other isotopes in cellulose (δ{sup 18}O or δ{sup 13}C), it is challenging to obtain high-resolution records, especially for slow-growing trees at high elevations and in boreal regions. Here, we tested whether annually pooled samples of Qinghai spruce (Picea crassifolia Kom.) trees from northwestern China provided results similar to those derived as the mean of individual measurements of the same trees and whether the resulting chronologies recorded useful climate information. Inter-tree variability of δD was higher than that of measured ring width for the same trees. We found higher and significant coherence between pooled and mean isotope chronologies than that among the individual series. It showed a logarithmic relationship between ring mass and δD; however, accounting for the influence of ring mass on δD values only slightly improved the strength of climatic signals in the pooled records. Tree-ring δD was significantly positively correlated with the mean, maximum, and minimum temperatures during the previous winter and with maximum temperature during the current August, and significantly negatively correlated with precipitation in the previous November to January and the current July. The winter climate signal seems to dominate tree-ring δD through the influence of large-scale atmospheric circulation patterns, i.e. the Arctic Oscillation. These results will facilitate reconstruction of winter atmospheric circulation patterns over northwestern China based on a regional tree-ring δD networks. - Highlights: • The difference between mean and pooled tree-ring δD chronologies was tested. • High coherence between the chronologies for northwestern China. • Tree-ring

  19. Pooled versus separate tree-ring δD measurements, and implications for reconstruction of the Arctic Oscillation in northwestern China

    International Nuclear Information System (INIS)

    Liu, Xiaohong; An, Wenling; Treydte, Kerstin; Wang, Wenzhi; Xu, Guobao; Zeng, Xiaomin; Wu, Guoju; Wang, Bo; Zhang, Xuanwen

    2015-01-01

    Stable hydrogen isotope ratios (δD) in tree rings are an attractive but still rarely explored terrestrial archive of past climatic information. Because the preparation of the cellulose nitrate for δD measurements requires more wood and a longer preparation time than preparation techniques for other isotopes in cellulose (δ 18 O or δ 13 C), it is challenging to obtain high-resolution records, especially for slow-growing trees at high elevations and in boreal regions. Here, we tested whether annually pooled samples of Qinghai spruce (Picea crassifolia Kom.) trees from northwestern China provided results similar to those derived as the mean of individual measurements of the same trees and whether the resulting chronologies recorded useful climate information. Inter-tree variability of δD was higher than that of measured ring width for the same trees. We found higher and significant coherence between pooled and mean isotope chronologies than that among the individual series. It showed a logarithmic relationship between ring mass and δD; however, accounting for the influence of ring mass on δD values only slightly improved the strength of climatic signals in the pooled records. Tree-ring δD was significantly positively correlated with the mean, maximum, and minimum temperatures during the previous winter and with maximum temperature during the current August, and significantly negatively correlated with precipitation in the previous November to January and the current July. The winter climate signal seems to dominate tree-ring δD through the influence of large-scale atmospheric circulation patterns, i.e. the Arctic Oscillation. These results will facilitate reconstruction of winter atmospheric circulation patterns over northwestern China based on a regional tree-ring δD networks. - Highlights: • The difference between mean and pooled tree-ring δD chronologies was tested. • High coherence between the chronologies for northwestern China. • Tree-ring

  20. 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

  1. Evaluation for the effects of a ring plate device to eliminate free surface gradients in liquid metal fast breeder reactor vessel using multi-dimensional thermohydraulics computer code

    International Nuclear Information System (INIS)

    Gao Ming Qing.

    1997-02-01

    There is a free surface at the upper plenum in a reactor vessel of LMFBR. The free surface has spatial gradient caused by the internal coolant flow. This is a disadvantageous factor to engineering from the view point of gas entrainment into coolant. To eliminate the free surface gradients, ring plates about 20 cm wide are fitted at about 1 meter under the free surface. They interfere fluid flow, and decrease the component velocity in vertical direction. To investigate the efficiency of the ring plates, analyses with the AQUA-VOF code were carried out. For contrast, three conditions were given: Case-1: Without ring plates. Case-2: Ring plates, fitted at 1.125 m under the free surface. Case-3: Ring plates, fitted at 1.5 m under the free surface. The results shown that the ring plates have a sufficiently high potential to eliminate the free surface gradients due to disperse the momentum along reactor vessel axis to radial direction. In the calculations with ring plate (Cases-2 and -3), the maximum free surface height differences and the maximum gradients of free surface were decreased to less than 15% and 64% compared with the case without ring plates, respectively. (author)

  2. First results for a FCC-hh ring optics design

    CERN Document Server

    Chance, Antoine; Payet, Jacques; Alemany Fernandez, Reyes; Holzer, Bernhard; Schulte, Daniel

    2015-01-01

    The first order considerations of the optics for the FCC-hh ring are presented. The arc cell is generated taking into account some general considerations like the whole circumference, maximum gradients and lengths of the elements in the cell. The integration of the insertion regions started. Three types of Dispersion Suppressors (DIS) are studied. The sensitivity of the arc parameters to these layout considerations is studied in more detail. An alternative layout is shown as well.

  3. A single-frequency, ring cavity Tm-doped fiber laser based on a CMFBG filter

    International Nuclear Information System (INIS)

    Li, Qi; Yan, Fengping; Peng, Wanjing; Liu, Shuo; Feng, Ting; Tan, Siyu; Liu, Peng

    2013-01-01

    A single-frequency (SF), continuous-wave (CW), ring cavity Tm-doped fiber laser has been proposed and demonstrated. A chirped moiré fiber grating (CMFBG) was used as an ultra-narrow filter in the laser cavity to ensure SF operation. When the launched pump power was fixed at 2 W, this proposed laser was in stable operation with a central wavelength, optical signal-to-noise ratio, and full width at half maximum of 1942.8140 nm, 47 dB, and 0.0522 nm, respectively, with a resolution of 0.05 nm. The maximum output power of this laser is 95 mW, a higher output power is restricted by the optical circulator that is used in the cavity. The SF operation of this laser was confirmed by the self-homodyne method. To the best of the authors’ knowledge, this is the first report on an SF, CW, ring cavity Tm-doped fiber laser with a CMFBG filter. (letter)

  4. Climate signal age effects in boreal tree-rings: Lessons to be learned for paleoclimatic reconstructions

    Czech Academy of Sciences Publication Activity Database

    Konter, O.; Büntgen, Ulf; Carrer, M.; Timonen, M.; Esper, J.

    2016-01-01

    Roč. 142, JUN (2016), s. 164-172 ISSN 0277-3791 Institutional support: RVO:67179843 Keywords : temperature variability * Age trends * Dendroclimatology * Growth-climate relationships * Maximum latewood density * Northern Scandinavia * Tree-ring width Subject RIV: EH - Ecology, Behaviour Impact factor: 4.797, year: 2016

  5. 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.

  6. On the energy dependence of the relative contributions ionospheric and solar sources of the ring current protons

    International Nuclear Information System (INIS)

    Kovtyukh, A.

    2007-01-01

    The energy dependence of a fraction of ring current protons of i onospheric origin is calculated using the AMPTE/CCE data for a typical magnetic storm (D st = -120 nT). It is shown that at L = 6-7 (L is the Mcllwain parameter) this fraction monotonically decreases from ∼83 to 25-30% with an increase in proton energy from 5 to 315 keV and is 30-40% at energy 40-50 keV corresponding to the maximum of proton energy density at L 6-7. It is evident that the core of the ring current (L = 3.7-4.7) is enriched by solar protons with E∼10-200 keV during storm main phase (the maximum effect is achieved at E∼20-50 keV). (author)

  7. Undulator sources at a 8 GeV storage ring

    International Nuclear Information System (INIS)

    Harami, Taikan.

    1989-06-01

    The use of undulators plays an important role as a high brilliance sources of synchrotron photon at a facility having an electron (or positron) storage ring. This paper describes the characteristics, tunability from gap variation and brilliance of synchrotron photon from undulators at a 8 GeV storage ring. The numerical studies show the following results. (1) Undulators for a 8 GeV storage ring can cover the first harmonic photon energy range from about 0.3 to 30 keV and the third harmonic photon from 0.85 to 70 keV. (2) The brilliance of undulator can be expected to be the order of 10 21 photons/(sec mm 2 mrad 2 0.1% band width mA), without size and angular spread in the electron beam (diffraction limit). (3) The peak brilliance has a broad maximum as a function of β function of the lattice and is shown to be practically independent on the β function. The peak brilliance is calculated to be the order of 10 16 photons/(sec mm 2 mrad 2 0.1% band width mA) at the electron beam emittance of 5 x 10 -9 m·rad (undulator length 2 m). (4) The nuclei of 57 Fe, 119 Sn and 238 U are expected to be the candidates for the Moessbauer scattering experiment using synchrotron photon from a 8 GeV storage ring. (author)

  8. 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

  9. 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

  10. 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

  11. Status and biology of ringed seals (Phoca hispida in Svalbard

    Directory of Open Access Journals (Sweden)

    Christian Lydersen

    1998-06-01

    water prior to weaning. They are capable of diving for up to 12min and dive to the bottom of the study areas (max. 89 m. Nursing females spend more than 80% of their time in the water. Maximum recorded dive duration for mothers was 21.2 min. In order to produce a weaned pup, the net energy expenditure for a ringed seal mother is 1,073 MJ. This energy value corresponds to the consumption of 185 kg of polar cod or 282 kg of P. libellula. The annual gross energy consumption for adult males and females is calculated to be 5,600 MJ and 7,300 MJ, respectively. The main predators of ringed seals in Svalbard are polar bears (Ursus maritimus and Arctic foxes (Alopex lagopus. In addition, both glaucous gulls (Larus hyperboreus and walruses (Odobenus rosmarus are documented as predators of ringed seals in this area. Heavy predation pressure is probably the main factor explaining why pups of this species start diving at such a young age, why they have access to so many breathing holes (8.7 on average and why they keep their white coat long after its thermoregulatory properties have vanished. Pollution levels in ringed seals from Svalbard are, generally speaking, similar to levels in other areas of the Arctic.

  12. Record of the Solar Activity and of Other Geophysical Phenomenons in Tree Ring

    Science.gov (United States)

    Rigozo, Nivaor Rodolfo

    1999-01-01

    Tree ring studies are usually used to determine or verify climatic factors which prevail in a given place or region and may cause tree ring width variations. Few studies are dedicated to the geophysical phenomena which may underlie these tree ring width variations. In order to look for periodicities which may be associated to the solar activity and/or to other geophysical phenomena which may influence tree ring growth, a new interactive image analysis method to measure tree ring width was developed and is presented here. This method makes use of a computer and a high resolution flatbed scanner; a program was also developed in Interactive Data Language (IDL 5.0) to study ring digitized images and transform them into time series. The main advantage of this method is the tree ring image interactive analysis without needing complex and high cost instrumentation. Thirty-nine samples were collected: 12 from Concordia - S. C., 9 from Canela - R. S., 14 from Sao Francisco de Paula - R. S., one from Nova Petropolis - R. S., 2 from Sao Martinho da Serra - R. S. e one from Chile. Fit functions are applied to ring width time series to obtain the best long time range trend (growth rate of every tree) curves and are eliminated through a standardization process that gives the tree ring index time series from which is performed spectral analysis by maximum entropy method and iterative regression. The results obtained show periodicities close to 11 yr, 22 yr Hale solar cycles and 5.5 yr for all sampling locations 52 yr and Gleissberg cycles for Concordia - S. C. and Chile samples. El Nino events were also observed with periods around 4 e 7 yr.

  13. 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.

  14. 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

  15. Photocapacitance study of type-II GaSb/GaAs quantum ring solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wagener, M. C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Carrington, P. J.; Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-01-07

    In this study, the density of states associated with the localization of holes in GaSb/GaAs quantum rings are determined by the energy selective charging of the quantum ring distribution. The authors show, using conventional photocapacitance measurements, that the excess charge accumulated within the type-II nanostructures increases with increasing excitation energies for photon energies above 0.9 eV. Optical excitation between the localized hole states and the conduction band is therefore not limited to the Γ(k = 0) point, with pseudo-monochromatic light charging all states lying within the photon energy selected. The energy distribution of the quantum ring states could consequently be accurately related from the excitation dependence of the integrated photocapacitance. The resulting band of localized hole states is shown to be well described by a narrow distribution centered 407 meV above the GaAs valence band maximum.

  16. Radio frequency system of the RIKEN ring cyclotron

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  17. 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.

  18. 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

  19. Pooled versus separate tree-ring δD measurements, and implications for reconstruction of the Arctic Oscillation in northwestern China.

    Science.gov (United States)

    Liu, Xiaohong; An, Wenling; Treydte, Kerstin; Wang, Wenzhi; Xu, Guobao; Zeng, Xiaomin; Wu, Guoju; Wang, Bo; Zhang, Xuanwen

    2015-04-01

    Stable hydrogen isotope ratios (δD) in tree rings are an attractive but still rarely explored terrestrial archive of past climatic information. Because the preparation of the cellulose nitrate for δD measurements requires more wood and a longer preparation time than preparation techniques for other isotopes in cellulose (δ18O or δ13C), it is challenging to obtain high-resolution records, especially for slow-growing trees at high elevations and in boreal regions. Here, we tested whether annually pooled samples of Qinghai spruce (Picea crassifolia Kom.) trees from northwestern China provided results similar to those derived as the mean of individual measurements of the same trees and whether the resulting chronologies recorded useful climate information. Inter-tree variability of δD was higher than that of measured ring width for the same trees. We found higher and significant coherence between pooled and mean isotope chronologies than that among the individual series. It showed a logarithmic relationship between ring mass and δD; however, accounting for the influence of ring mass on δD values only slightly improved the strength of climatic signals in the pooled records. Tree-ring δD was significantly positively correlated with the mean, maximum, and minimum temperatures during the previous winter and with maximum temperature during the current August, and significantly negatively correlated with precipitation in the previous November to January and the current July. The winter climate signal seems to dominate tree-ring δD through the influence of large-scale atmospheric circulation patterns, i.e. the Arctic Oscillation. These results will facilitate reconstruction of winter atmospheric circulation patterns over northwestern China based on a regional tree-ring δD networks. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. 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)

  1. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Global coupling and decoupling of the APS storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Y.C.; Liu, J.; Teng, L.C.

    1993-07-01

    This paper describes a study of controlling the coupling between the horizontal and the vertical betatron oscillations in the 7-GeV Advanced Photon Source (APS) storage ring. First, we investigate the strengthening of coupling using two families of skew quadrupoles. Twenty skew quadrupoles are arranged in the 40 sectors of the storage ring and powered in such a way so as to generate both quadrature components of the required 21st harmonic. The numerical results from tracking a single particle are presented for the various configurations of skew quadrupoles. Second, we describe the global decoupling procedure to minimize the unwanted coupling effects. These are mainly due to the random roll errors of normal quadruples. It is shown that even with the rather large rms roll error of 2 mrad, the coupling effects can be compensated for with 20 skew quadrupoles each having maximum strength one order of magnitude lower than the typical normal quadrupole strength.

  7. 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...

  8. Optimum Energy Extraction from Coherent Vortex Rings Passing Tangentially Over Flexible Plates

    Science.gov (United States)

    Pirnia, Alireza; Browning, Emily A.; Peterson, Sean D.; Erath, Byron D.

    2017-11-01

    Coherent vortical structures can incite self-sustained oscillations in flexible membranes. This concept has recently gained interest for energy extraction from ambient environments. In this study the special case of a vortex ring passing tangentially over a cantilevered flexible plate is investigated. This problem is governed by the Kirchhoff-Love plate equation, which can be expressed in terms of a non-dimensional mass parameter of the plate, non-dimensional pressure loading induced by the vortex ring, and a Strouhal (St) number which expresses the duration of pressure loading relative to the period of plate oscillation. For a plate with a fixed mass parameter immersed in a fluid environment, the St number specifies the beam dynamics and the energy exchange process. The aim of this study is to identify the St number corresponding to maximum energy exchange between plates and vortex rings. The energy exchange process between the vortex ring and the plate is investigated over a range of 0.3 transfer is reported in each case and an empirical correlation is provided for predictive purposes. Supported by the National Science Foundation (NSF) under Grant No. CBET-1511761, and the Natural Sciences and Engineering Research Council of Canada (NSERC), under Grant No. 05778-2015.

  9. 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.

  10. 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.

  11. Design of a 4.8-m ring for inverse Compton scattering x-ray source

    Directory of Open Access Journals (Sweden)

    H. S. Xu

    2014-07-01

    Full Text Available In this paper we present the design of a 50 MeV compact electron storage ring with 4.8-meter circumference for the Tsinghua Thomson scattering x-ray source. The ring consists of four dipole magnets with properly adjusted bending radii and edge angles for both horizontal and vertical focusing, and a pair of quadrupole magnets used to adjust the horizontal damping partition number. We find that the dynamic aperture of compact storage rings depends essentially on the intrinsic nonlinearity of the dipole magnets with small bending radius. Hamiltonian dynamics is found to agree well with results from numerical particle tracking. We develop a self-consistent method to estimate the equilibrium beam parameters in the presence of the intrabeam scattering, synchrotron radiation damping, quantum excitation, and residual gas scattering. We also optimize the rf parameters for achieving a maximum x-ray flux.

  12. Ring current and auroral electrojets in connection with interplanetary medium parameters during magnetic storm

    Directory of Open Access Journals (Sweden)

    Y. I. Feldstein

    1994-06-01

    Full Text Available The relationship between the auroral electrojet indices (AE and the ring current magnetic field (DR was investigated by observations obtained during the magnetic storm on 1-3 April 1973. During the storm main phase the DR development is accompanied by a shift of the auroral electrojets toward the equator. As a result, the standard AE indices calculated on the basis of data from auroral observatories was substantially lower than the real values (AE'. To determine AE' during the course of a storm main phase data from subauroral magnetic observatories should be used. It is shown that the intensity of the indices (AE' which take into account the shift of the electrojets is increased substantially relative to the standard indices during the storm main phase. AE' values are closely correlated with geoeffective solar wind parameters. A high correlation was obtained between AE' and the energy flux into the ring current during the storm main phase. Analysis of magnetic field variations during intervals with intense southward IMF components demonstrates a decrease of the saturation effect of auroral electrojet currents if subauroral stations magnetic field variations are taken into account. This applies both to case studies and statistical data. The dynamics of the electrojets in connection with the development of the ring current and of magnetospheric substorms can be described by the presence (absence of saturation for minimum (maximum AE index values during a 1-h interval. The ring current magnetic field asymmetry (ASY was calculated as the difference between the maximum and minimum field values along a parallel of latitude at low latitudes. The ASY value is closely correlated with geoeffective solar wind parameters and simultaneously is a more sensitive indicator of IMF Bz variations than the symmetric ring current. ASY increases (decreases faster during the main phase (the recovery phase than DR. The magnetic field decay at low latitudes in the

  13. 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

  14. 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.

  15. 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.

  16. 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.

  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. Maximum dislodging forces of mandibular implant-assisted removable partial dentures: in vitro assessment.

    Science.gov (United States)

    Gharehchahi, Jafar; Asadzadeh, Nafiseh; Mirmortazavi, Amirtaher; Shakeri, Mohammad Taghi

    2013-10-01

    The initial retention of implant-assisted removable partial dentures (IARPDs) is unknown. The purpose of this in vitro study was to compare maximum dislodging forces of distal extension mandibular IARPD with two different attachments and three clasp designs. A simulated class I partially edentulous mandible was prepared with two screw-type 3.75 × 12 mm implants in the first molar regions and 2 metal-ceramic crowns on distal abutments. Fifteen bilateral distal extension frameworks were conventionally fabricated in three clasp designs (suprabulge, infrabulge, no clasp). Locator attachments were connected to the 15 denture bases with autopolymerized resin. Each specimen was subject to four types of retention pulls (main, anterior, posterior, unilateral pull) five times with a universal testing machine. Locator attachments were replaced with O-ring attachments, and the same procedure was performed. Therefore, the study groups included: IRPD with Locator attachment and suprabulge clasp (group 1), IRPD with Locator attachment and infrabulge clasp (group 2), IRPD with Locator attachment and no clasp (group 3), IRPD with O-ring attachment and suprabulge clasp (group 4), IRPD with O-ring attachment and infrabulge clasp (group 5), IRPD with O-ring attachment and no clasp (group 6). Data were analyzed using one-way ANOVA, two-way ANOVA, and Tukey tests. The highest mean value was 22.99 lb for prostheses with a Locator attachment and suprabulge clasp. The lowest retentive values were recorded for IARPDs with O-ring attachments. The results of this in vitro study suggest that the precise selection of attachments with or without clasp assemblies may affect the clinical success of mandibular IARPDs. © 2013 by the American College of Prosthodontists.

  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. Topological optimization of opening fence brackets on ring-stiffened cylindrical shell

    Directory of Open Access Journals (Sweden)

    SONG Xiaofei

    2018-02-01

    Full Text Available [Objectives] Stress concentration is prone to take place at connections between the opening fence and ring ribs of a ring-stiffened cylindrical shell under external pressure. [Methods] In this paper, a topological optimization method for the brackets that connect the fence to the ring ribs is proposed in order to effectively reduce the local high stress in the brackets. The sub-model technique is used to analyze the stress of the connecting brackets. In the design, the connection brackets are used as design variables and the stress of the shell, fence and ribs are used as constraints. The maximum stress of the bracket is minimized as the objective function. The topology optimization results are engineered to obtain the final form of the brackets. [Results] The calculation results show that brackets of which the panel is partially widened can effectively reduce the stress concentration position of the opening fence transverse offset if the side of the bracket away from the longitudinal section is longer; the opening fence is offset relative to the brackets, and the symmetrical design of the brackets is feasible. [Conclusions] This research provides a reference for similar structural design.

  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. Electron density profile reconstruction by maximum entropy method with multichannel HCN laser interferometer system on SPAC VII

    International Nuclear Information System (INIS)

    Kubo, S.; Narihara, K.; Tomita, Y.; Hasegawa, M.; Tsuzuki, T.; Mohri, A.

    1988-01-01

    A multichannel HCN laser interferometer system has been developed to investigate the plasma electron confinement properties in SPAC VII device. Maximum entropy method is applied to reconstruct the electron density profile from measured line integrated data. Particle diffusion coefficient in the peripheral region of the REB ring core spherator was obtained from the evolution of the density profile. (author)

  8. 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…

  9. 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.

  10. On the Magnitude and Orientation of Stress during Shock Metamorphism: Understanding Peak Ring Formation by Combining Observations and Models.

    Science.gov (United States)

    Rae, A.; Poelchau, M.; Collins, G. S.; Timms, N.; Cavosie, A. J.; Lofi, J.; Salge, T.; Riller, U. P.; Ferrière, L.; Grieve, R. A. F.; Osinski, G.; Morgan, J. V.; Expedition 364 Science Party, I. I.

    2017-12-01

    Shock metamorphism occurs during the earliest moments after impact. The magnitude and orientation of shock leaves recordable signatures in rocks, which spatially vary across an impact structure. Consequently, observations of shock metamorphism can be used to understand deformation and its history within a shock wave, and to examine subsequent deformation during crater modification. IODP-ICDP Expedition 364 recovered nearly 600 m of shocked target rocks from the peak ring of the Chicxulub Crater. Samples from the expedition were used to measure the magnitude and orientation of shock in peak ring materials, and to determine the mechanism of peak-ring emplacement. Here, we present the results of petrographic analyses of the shocked granitic target rocks of the Chicxulub peak ring; using universal-stage optical microscopy, back-scattered electron images, and electron back-scatter diffraction. Deformation microstructures in quartz include planar deformation features (PDFs), feather features (FFs), which are unique to shock conditions, as well as planar fractures and crystal-plastic deformation bands. The assemblage of PDFs in quartz suggest that the peak-ring rocks experienced shock pressures of 15 GPa throughout the recovered drill core, and that the orientation of FFs are consistent with the present-day orientation of the maximum principal stress direction during shock is close to vertical. Numerical impact simulations of the impact event were run to determine the magnitude and orientation of principal stresses during shock and track those orientations throughout crater formation. Our results are remarkably consistent with the geological data, and accurately predict both the shock-pressure magnitudes, and the final near-vertical orientation of the direction of maximum principal stress in the shock wave. Furthermore, analysis of the state of stress throughout the impact event can be used to constrain the timing of fracture and fault orientations observed in the core

  11. 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.

  12. 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

  13. 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

  14. Determination of self shielding factors and gamma attenuation effects for tree ring samples

    International Nuclear Information System (INIS)

    Dagistan Sahin; Kenan Uenlue

    2012-01-01

    Determination of tree ring chemistry using Neutron Activation Analysis (NAA) is part of an ongoing research between Penn State University (PSU) and Cornell University, The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology. Tree-ring chemistry yields valuable data for environmental event signatures. These signatures are a complex function of elemental concentration. To be certain about concentration of signature elements, it is necessary to perform the measurements and corrections with the lowest error and maximum accuracy possible. Accurate and precise values of energy dependent neutron flux at dry irradiation tubes and detector efficiency for tree ring sample are calculated for Penn State Breazeale Reactor (PSBR). For the calculation of energy dependent and self shielding corrected neutron flux, detailed model of the TRIGA Mark III reactor at PSU with updated fuel compositions was prepared using the MCNP utility for reactor evolution (MURE) libraries. Dry irradiation tube, sample holder and sample were also included in the model. The thermal flux self-shielding correction factors due to the sample holder and sample for were calculated and verified with previously published values. The Geant-4 model of the gamma spectroscopy system, developed at Radiation Science and Engineering Center (RSEC), was improved and absolute detector efficiency for tree-ring samples was calculated. (author)

  15. 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.

  16. A Study for Shelf Life Evaluation of Rubber O-ring

    International Nuclear Information System (INIS)

    Jung, Sun Chul; Kim, Jong Seog

    2005-01-01

    Non-metallic materials stored in warehouses in nuclear power plants have shelf life. The shelf life means the maximum storage time allowable such that the install life of the material is not affected. Materials whose shelf lives expire are generally discarded. unless the shelf lives of these materials can be extended by reducing the install life. Examples of this case are rubber materials. Rubber materials are widely used for sealing of various machines. There are various life evaluation methods for rubber material. For example, the compression set is generally used for evaluation the aging condition of rubber materials used for sealing. A compression set value can be calculated according to the ASTM D395. We have tried the compression set test by using specimens with 6.99mm diameter O-ring even when ASTM D 395 recommends the use of bar specimen. Test results and comparison between O-ring and reference data of EPRI NP-6608 are presented below

  17. 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.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    R Serafin

    2008-12-01

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

  20. 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....

  1. 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 ...

  2. 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.

  3. 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.

  4. 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.

  5. Development of a Single Detector Ring Micro Crystal Element Scanner: QuickPET II

    Directory of Open Access Journals (Sweden)

    Robert S. Miyaoka

    2005-04-01

    Full Text Available This article describes a single ring version of the micro crystal element scanner (MiCES and investigation of its spatial resolution imaging characteristics for mouse positron emission tomography (PET imaging. This single ring version of the MiCES system, referred to as QuickPET II, consists of 18 MiCE detector modules mounted as a single ring in a vertical gantry. The system has a 5.76-cm transverse field of view and a 1.98-cm axial field of view. In addition to the scanner and data acquisition system, we have developed an iterative reconstruction that includes a model of the system's detector response function. Evaluation images of line sources and mice have been acquired. Using filtered backprojection, the resolution for a reconstructed line source has been measured at 1.2 mm full width at half maximum. F-18-2-fluoro-2-deoxyglucose mouse PET images are provided. The result shows that QuickPET II has the imaging characteristics to support high-resolution, static mouse PET studies using 18-F labeled compounds.

  6. 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

  7. An experimental determination of the hot electron ring geometry in a Bumpy Torus and its implications for Bumpy Torus stability

    International Nuclear Information System (INIS)

    Hillis, D.L.; Wilgen, J.B.; Bigelow, T.S.; Jaeger, E.F.; Swain, D.W.; Hankins, O.E.; Juhala, R.E.

    1986-10-01

    The hot electron rings of the ELMO Bumpy Torus (EBT) [Plasma Physics and Controlled Nuclear Fusion (IAEA, Vienna, 1975), Vol. II, p. 141] are formed by electron cyclotron resonance heating (ECRH) and have an electron temperature of 350 to 500 keV. The original intention of these hot electron rings was to provide a local minimum in the magnetic field and, thereby, stabilize the simple interchange and flute modes, which are inherent in a closed field line bumpy torus. To evaluate the electron energy density of the EBT rings and determine if enough stored energy is present to provide a local minimum in the magnetic field, a detailed understanding of the spatial distribution of the rings is imperative. The purpose of this report is to measure the ring thickness and investigate its implications for bumpy torus stability. The spatial location and radial profile of the hot electron ring are measured with a unique metal ball pellet injector, which injects small metallic balls into the EBT ring plasma. From these measurements the radial extent (or ring thickness) is about 5 to 7 cm full width at half maximum for typical EBT operation, which is much larger than previously expected. These measurements and recent modeling of the EBT plasma indicate that the hot electron ring's stored energy may not be sufficient to produce a local minimum in the magnetic field

  8. 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.

  9. 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.

  10. 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

  11. Impact of Different Standard Type A7A Drum Closure-Ring Practices on Gasket Contraction and Bolt Closure Distance– 15621

    Energy Technology Data Exchange (ETDEWEB)

    Ketusky, Edward [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Blanton, Paul [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Bobbitt, John H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-11

    The Department of Energy, the Savannah River National Laboratory, several manufacturers of specification drums, and the United States Department of Transportation (DOT) are collaborating in the development of a guidance document for DOE contractors and vendors who wish to qualify containers to DOT 7A Type A requirements. Currently, the effort is focused on DOT 7A Type A 208-liter (55-gallons) drums with a standard 12-gauge bolted closure ring. The U.S. requirements, contained in Title 49, Part 178.350 “Specification 7A; general packaging, Type A specifies a competent authority review of the packaging is not required for the transport of (Class 7) radioactive material containing less than Type A quantities of radioactive material. For Type AF drums, a 4 ft. regulatory free drop must be performed, such that the drum “suffers maximum damage.” Although the actual orientation is not defined by the specification, recent studies suggest that maximum damage would result from a shallow angle top impact, where kinetic energy is transferred to the lid, ultimately causing heavy damage to the lid, or even worse, causing the lid to come off. Since each vendor develops closure recommendations/procedures for the drums they manufacture, key parameters applied to drums during closing vary based on vendor. As part of the initial phase of the collaboration, the impact of the closure variants on the ability of the drum to suffer maximum damage is investigated. Specifically, closure testing is performed varying: 1) the amount of torque applied to the closure ring bolt; and, 2) stress relief protocol, including: a) weight of hammer; and, b) orientation that the hammer hits the closure ring. After closure, the amount of drum lid gasket contraction and the distance that the closure bolt moves through the closure ring is measured.

  12. Note on Ideal Based Zero-Divisor Graph of a Commutative Ring

    Directory of Open Access Journals (Sweden)

    Mallika A.

    2017-12-01

    Full Text Available In this paper, we consider the ideal based zero divisor graph ΓI(R of a commutative ring R. We discuss some graph theoretical properties of ΓI(R in relation with zero divisor graph. We also relate certain parameters like vertex chromatic number, maximum degree and minimum degree for the graph ΓI(R with that of Γ(R/I . Further we determine a necessary and sufficient condition for the graph to be Eulerian and regular.

  13. Ring design of the Prague synchrotron for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Molodozhentsev, A.; Makoveev, V.; Minashkin, V.; Shevtsov, V.; Sidorov, G. [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Prokesh, K.; Sedlak, J.; Kuzmiak, M. [``Oncology 2000`` Foundation, Prague (Czech Republic)

    1998-04-01

    The paper presents main elements of a dedicated proton synchrotron for hadron therapy. The beam parameters for active scanning of tumours are discussed. The output energy of the beam should be variable in the range 60-220 MeV. The average current of the proton beam is equal to 10 nA. The repetition rate of the accelerator is chosen of 1 Hz to get a spill time for slow extraction of about 500 ms. The timing cycle of the accelerator including the quasi-adiabatic capture process and acceleration is described. The RF gymnastics is utilized to prepare the unbunched beam for slow extraction. The magnetic elements of the ring, compact RF and VCO systems are presented in the paper. The maximum magnet field of the dipole magnet should be 1.2 T and the maximum magnetic field on the pole of the quadrupole lenses should be less than 1 T. The resonator should work on the first harmonic with a frequency from 1.298 MHz till 4.804 MHz. The length of the resonator should be less than 1 m. The maximum voltage on the accelerator gap should be about 2 kV. (orig.) 5 refs.

  14. 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.

  15. Theoretical investigations of the structures and electronic spectra of 8-hydroxylquinoline derivatives

    Science.gov (United States)

    Ning, Pan; Ren, Tiegang; Zhang, Yanxin; Zhang, Jinglai

    2013-11-01

    The spectroscopic properties of 8-hydroxyquinoline derivatives are theoretically investigated by means of density functional theory (DFT) and time-dependent density functional theory (TD-DFT) methods. The target molecules are divided into two groups: group (I): (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)quinolin-8-ol (A), together with corresponding potential reaction products of A with acetic acid, i.e., (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)quinolin-8-yl acetate (AR1), and (E)-2-(2-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl)vinyl)-8-hydroxyquinolinium (AR2); group (II): (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)quinolin-8-ol (B), as well as potential reaction products of B with acetic acid, i.e., (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)quinolin-8-yl acetate (BR1), and (E)-2-(2-(1-(4-chlorophenyl)-3,5-dimethyl-1H-pyrazol-4-yl)vinyl)-8-hydroxyquinolinium (BR2). The geometries are optimized by B3LYP and M06 methods. The results indicate that product molecules tend to be effectively planar compared with reactants. Subsequently, UV absorption spectra are simulated through TD-DFT method with PCM model to further confirm the reasonable products of two reactions. AR2 and BR2 are identified as the target molecules through the experimental spectra for the real products. It is worth noting that the maximum absorption wavelengths of compounds AR2 and BR2 present prominent red shift compared the initial reactants A and B, respectively, which should be ascribed to the enhancive planarity of products that mentioned above and the decreased HOMO-LUMO energy gap. Geometric structures and optical properties for corresponding compounds are discussed in detail.

  16. 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...

  17. Generator of a dense atomic gas curtain (for use in Intersecting Storage Rings)

    CERN Document Server

    Zankel, K

    1975-01-01

    A supersonic beam source is described which continuously generates a gas curtain for the proton beam profile observation in the Intersecting Storage Rings at CERN. Its maximum intensity is 10/sup 20 / atoms/sr s. A commonly used theoretical model for the determination of the intensity downstream of the source is discussed. Some results about the condensation behaviour of sodium vapour on metallic substrate surfaces are reported. (8 refs).

  18. Erbium-doped fiber ring laser with SMS modal interferometer for hydrogen sensing

    Science.gov (United States)

    Zhang, Ya-nan; Zhang, Lebin; Han, Bo; Peng, Huijie; Zhou, Tianmin; Lv, Ri-qing

    2018-06-01

    A hydrogen sensor based on erbium-doped fiber ring laser with modal interferometer is proposed. A single mode-multimode-single mode (SMS) modal interferometer structure coated with Pd/WO3 film is used as the sensing head, due to that it is easy to be fabricated and low cost. The sensing structure is inserted into an erbium-doped fiber ring laser in order to solve the problem of spectral confusion and improve the detection limit of the hydrogen sensor based on the SMS modal interferometer. The SMS sensing structure is acted as a fiber band-pass filter. When hydrogen concentration around the sensor is changed, it will induce the refractive index and strain variations of the Pd/WO3 film, and then shift the resonant spectrum of the SMS modal interferometer as well as the laser wavelength of the fiber ring laser. Therefore, the hydrogen concentration can be measured by monitoring the wavelength shift of the laser, which has high intensity and narrow full width half maximum. Experimental results demonstrate that the sensor has high sensitivity of 1.23 nm/%, low detection limit of 0.017%, good stability and excellent repeatability.

  19. Numerical Simulation and Experimental Study on Temperature Distribution of Self-Lubricating Packing Rings in Reciprocating Compressors

    Directory of Open Access Journals (Sweden)

    Jia Xiaohan

    2016-01-01

    Full Text Available The nonuniform abrasion failure and high-temperature thermal failure of packing rings have a significant influence on compressor reliability, particularly that of oil-free compressors. In this study, a test rig was constructed to measure the dynamic temperature of packing rings under different operational conditions in an oil-free reciprocating compressor. The dynamic axial and radial temperature distributions of the packing rings were obtained using an innovative internal temperature testing device that kept the thermocouples and packing box relatively static during compressor operation. A three-dimensional heat transfer model was also developed to analyze the temperature distribution of the packing boxes, piston rod, and cylinder during such operation. Good agreement was observed between the simulation results and experimental data, which showed an average relative error of less than 2.35%. The results indicate that the pressure ratio exerts a significant effect on the axial temperature distribution and determines which packing ring reaches the maximum temperature. They also show the average temperature to rise with an increase in the rotational speed and to fall with an improvement in the external cooling conditions. Finally, the material of the packing rings was found to affect the temperature gradient from their inner to outer surface.

  20. 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)

  1. 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.

  2. 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 ...

  3. 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.

  4. Ring current and auroral electrojets in connection with interplanetary medium parameters during magnetic storm

    Directory of Open Access Journals (Sweden)

    Y. I. Feldstein

    Full Text Available The relationship between the auroral electrojet indices (AE and the ring current magnetic field (DR was investigated by observations obtained during the magnetic storm on 1-3 April 1973. During the storm main phase the DR development is accompanied by a shift of the auroral electrojets toward the equator. As a result, the standard AE indices calculated on the basis of data from auroral observatories was substantially lower than the real values (AE'. To determine AE' during the course of a storm main phase data from subauroral magnetic observatories should be used. It is shown that the intensity of the indices (AE' which take into account the shift of the electrojets is increased substantially relative to the standard indices during the storm main phase. AE' values are closely correlated with geoeffective solar wind parameters. A high correlation was obtained between AE' and the energy flux into the ring current during the storm main phase. Analysis of magnetic field variations during intervals with intense southward IMF components demonstrates a decrease of the saturation effect of auroral electrojet currents if subauroral stations magnetic field variations are taken into account. This applies both to case studies and statistical data. The dynamics of the electrojets in connection with the development of the ring current and of magnetospheric substorms can be described by the presence (absence of saturation for minimum (maximum AE index values during a 1-h interval. The ring current magnetic field asymmetry (ASY was calculated as the difference between the maximum and minimum field values along a parallel of latitude at low latitudes. The ASY value is closely correlated with geoeffective solar wind parameters and simultaneously is a more sensitive indicator of IMF Bz variations than the symmetric ring current.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. Relaxant effects of a hydroalcoholic extract of Ruta graveolens on isolated rat tracheal rings

    Directory of Open Access Journals (Sweden)

    Luis Águila

    2015-01-01

    Full Text Available BACKGROUND: Ruta graveolens L. (R. graveolens is a medicinal plant employed in non-traditional medicines that has various therapeutic properties, including anthelmintic, and vasodilatory actions, among others. We evaluated the trachea-relaxant effects of hydroalcoholic extract of R. graveolens against potassium chloride (KCl- and carbachol-induced contraction of rat tracheal rings in an isolated organ bath. RESULTS: The results showed that the airway smooth muscle contraction induced by the depolarizing agent (KCl and cholinergic agonist (carbachol was markedly reduced by R. graveolens in a concentration-dependent manner, with maximum values of 109 ± 7.9 % and 118 ± 2.6 %, respectively (changes in tension expressed as positive percentages of change in proportion to maximum contraction, at the concentration of 45 μg/mL (half-maximal inhibitory concentration IC50: 35.5 μg/mL and 27.8 μg/mL for KCl- and carbachol-induced contraction, respectively. Additionally, the presence of R. graveolens produced rightward parallel displacement of carbachol dose-response curves and reduced over 35 % of the maximum smooth muscle contraction. CONCLUSIONS: The hydroalcoholic extract of R. graveolens exhibited relaxant activity on rat tracheal rings. The results suggest that the trachea-relaxant effect is mediated by a non-competitive antagonistic mechanism. More detailed studies are needed to identify the target of the inhibition, and to determine more precisely the pharmacological mechanisms involved in the observed biological effects.

  10. 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)

  11. 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...

  12. 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

  13. Distribution and growth of salps in a Kuroshio warm-core ring during summer 1987

    Science.gov (United States)

    Tsuda, Atsushi; Nemoto, Takahisa

    1992-03-01

    A salp bloom, accounting for 47% of the macrozooplankton wet weight in the upper 200 m, was observed in a Kuroshio warm-core ring and adjacent areas during September 1987. Although salps had wide distribution and high biomass in the ring and adjacent southern areas, they did not occur north of the northern ring front. Thalia democratica dominated in these areas and Salpa fusiformis was abundant at some stations. Salps were distributed only in the upper 200 m of the water column. The maximum abundance of T. democratica was in the surface mixed layer, 0-20 m. S. fusiformis was most abundant from 50 to 75 m. Diel vertical migration was observed only for solitary zooids of S. fusiformis. All other salps appeared only on the surface. The growth of aggregate zooids of T. democratica was investigated with the time-series sampling during a 28-h sampling period following a drifter. Several cohorts were identified in the length-frequency distributions. The average relative growth rate in length was 8.0% per hour. Carbon consumption by the T. democratica population, calculated from the derived growth rate, suggested that T. democratica was a major consumer of the primary production in the ring.

  14. Growth ring analysis of Euxylophora paraensis through x-ray microdensitometry

    Directory of Open Access Journals (Sweden)

    Eva Santos de Andrade

    Full Text Available ABSTRACT: Euxylophora paraensis Huber - Rutaceae, popularly known as yellow heart, is a species with a low-density population that has suffered intense exploitation in recent decades. This has led to its inclusion in the IBAMA list of endangered species. This study aimed to evaluate the existence of growth rings and their annuity in five trees of Euxylophora paraensis through the x-ray microdensitometry technique, as well as to compare them using the classical method. Application feasibility of this technique can be deepened through future, broader dendroecological studies, which may better elucidate the understanding of the species population dynamics and promote more sustainable uses. Wood disks were collected from the base of five 29-year-old trees from a planting site in the Curua-Una Experimental Station, located in Prainha, Pará State, Brazil. Samples were polished and sanded for the x-ray microdensitometric analysis. Values of minimum, average, and maximum density (0.581, 0.84, and 1.077gcm-3, respectively were obtained. There was a significant difference in density between the studied trees. Growth rings boundaries, through densitometric pith-bark profile are demarcated by fibrous zones, with density variation between the early wood and late wood. This study concludes that the growth rings of the studied species are distinct and annual, validating the technique used.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. A 250-Mbit/s ring local computer network using 1.3-microns single-mode optical fibers

    Science.gov (United States)

    Eng, S. T.; Tell, R.; Andersson, T.; Eng, B.

    1985-01-01

    A 250-Mbit/s three-station fiber-optic ring local computer network was built and successfully demonstrated. A conventional token protocol was employed for bus arbitration to maximize the bus efficiency under high loading conditions, and a non-return-to-zero (NRS) data encoding format was selected for simplicity and maximum utilization of the ECL-circuit bandwidth.

  20. 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

  1. Baroclinic flows, transports, and kinematic properties in a cyclonic-anticyclonic-cyclonic ring triad in the Gulf of Mexico

    Science.gov (United States)

    Vidal, VíCtor M. V.; Vidal, Francisco V.; HernáNdez, Abel F.; Meza, Eustorgio; PéRez-Molero, José M.

    1994-04-01

    referenced to 500 dbar. Within this layer, individual ring geometries were conserved. Maximum tangential ring velocities were 60 and 58 cm s-1, for the north and south cyclones respectively, and 30 cm s-1 for the anticyclone. The corresponding periods of revolution were 16, 19, and 26 days, and vertical velocities calculated at the rings' peripheries, where maximum horizontal divergence was encountered, were 1.5, 1.0, and -1.0 m d-1.

  2. 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.

  3. 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

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. Formation mechanism for the structure of the magnetic-storm ring current

    CERN Document Server

    Tverskoy, B A

    1999-01-01

    An analysis is presented for the implications of the relationship between the amplitude of the Dst variation and the position L sub m sub a sub x of the intensity maximum of the relativistic-electron belt that arises immediately after the cessation of a storm. The quantity L sub m sub a sub x is regarded to correspond to the position of the pressure maximum of the ring-current plasma at the moment of the maximum amplitude of the storm main phase. Under this assumption, the structure of the mentioned plasma formation is calculated, and the idea is substantiated that the plasma cloud is adiabatically driven deep into the magnetosphere during the sub-storm and subsequently symmetrized (this idea was originally put forward by the author on the basis of the theory of the magnetosphere-ionosphere interaction). It is shown that the presence of the mentioned relationship implies the existence of a certain boundary where the entropy calculated for a unit-magnetic-flux tube always has the same value. The applicability ...

  10. Formation mechanism for the structure of the magnetic-storm ring current

    International Nuclear Information System (INIS)

    Tverskoy, B.A.

    1999-01-01

    An analysis is presented for the implications of the relationship between the amplitude of the Dst variation and the position L max of the intensity maximum of the relativistic-electron belt that arises immediately after the cessation of a storm. The quantity L max is regarded to correspond to the position of the pressure maximum of the ring-current plasma at the moment of the maximum amplitude of the storm main phase. Under this assumption, the structure of the mentioned plasma formation is calculated, and the idea is substantiated that the plasma cloud is adiabatically driven deep into the magnetosphere during the sub-storm and subsequently symmetrized (this idea was originally put forward by the author on the basis of the theory of the magnetosphere-ionosphere interaction). It is shown that the presence of the mentioned relationship implies the existence of a certain boundary where the entropy calculated for a unit-magnetic-flux tube always has the same value. The applicability of the theory of low-pressure plasmas to the problem under study is justified

  11. 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

  12. Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii.

    Science.gov (United States)

    Meyer, Carl G; O'Malley, Joseph M; Papastamatiou, Yannis P; Dale, Jonathan J; Hutchinson, Melanie R; Anderson, James M; Royer, Mark A; Holland, Kim N

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13'17″N 109°52'14″W), in the southern Gulf of California (minimum distance between tag and recapture sites  =  approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Relationship between Antifungal Activity against Candida albicans and Electron Parameters of Selected N-Heterocyclic Thioamides

    Science.gov (United States)

    Stachowicz, Jadwiga; Krajewska-Kułak, Elżbieta; Łukaszuk, Cecylia; Niewiadomy, A.

    2014-01-01

    Due to the increasing demand for new pharmaceuticals showing biological activity against pathogenic microorganisms, there is increasing search for new compounds with predicted biological activity. Variously substituted thioamide derivatives with 1.3 and 1.2 ring of thiazole and 1,3,4-thiadiazole, as well as pyrazole were assessed for their activity against Candida albicans. Activity of majority of tested thioamides was larger as compared with that of the reference drugs. The electron parameters of obtained N-heterocyclic thioamides were determined and dependencies on their biological activity against Candida albicans were studied. The best electron compliance of produced bindings with the activity against Candida albicans was observed for the derivatives containing 1,3,4-thiadiazole ring. PMID:25284926

  18. Self-gravitation in Saturn's rings

    International Nuclear Information System (INIS)

    Salo, H.; Lukkari, J.

    1982-01-01

    In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)

  19. INJECTION CARBON STRIPPING FOIL ISSUES IN THE SNS ACCUMULATOR RING

    International Nuclear Information System (INIS)

    BEEBE-WANG, J.; LEE, Y.Y.; RAPARIA, D.; WEI, J.

    2001-01-01

    We are reporting the results of studies on issues related to the injection stripping foil in the Spallation Neutron Source (SNS) accumulator ring. The problems related to foil heating and foil lifetime, such as current density distribution and temperature distribution in the foil, are investigated. The impact of injection errors on the beam losses at the foil is studied. The particle traversal rate and the beam losses due to scattering in the foil are summarized. Finally, SNS end-to-end simulation results of the foil-missing rate, the foil-hitting rate and the maximum foil temperature are presented

  20. Contact behavior analysis of elastomeric x-ring under uniform squeeze rate and internal pressure before and after forcing-out using the photoelastic experimental hybrid method

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Alunda Ouma [Dedan Kimathi University of Technology, Nyeri (Kenya); Hawong, Jai Sug; Dong, Bai [Yeungnam University, Gyeongsan (Korea, Republic of); Shin, Dong Chul [Koje College, Geoje (Korea, Republic of)

    2015-05-15

    Many different types of elastomeric rings have been developed to suit various needs in industry. The X-ring was introduced as a result of the limitations of O-rings that twist, especially during dynamic application. A better understanding of the behavior and the stress distribution of the X-ring under a uniform squeeze rate and internal pressure is needed. We analyzed the contact stresses and internal stresses developed in an X-ring before and after forcing-out by using the photoelastic experimental hybrid method, ascertained the packing ability of an X-ring, and studied the failure criterion of an X-ring under uniform squeeze rate and internal pressure. Forcing-out in the X-ring occurred when the internal pressure was 3.92 MPa. After forcing-out, at an internal pressure of 5.88 MPa, the two lobes on the upper contact surface merged one contact side of the upper side immensely. Even after extrusion of the X-ring, the X-ring can be used to effectively contain the fluid. This is because the effects of extrusion on the X-ring affected the stress distribution of only two lobes close to the assembly gap and the two lobes are merge into one lobe. In addition, our experimental results show that the maximum shear failure criterion is suitable for the prediction of failure in X-ring seals.

  1. Saturn’s ring temperatures at equinox

    Science.gov (United States)

    Spilker, Linda J.; Ferrari, C.; Morishima, R.

    2013-10-01

    Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

  2. An experimental study on the long-term stability of particle motion in hadron storage rings

    International Nuclear Information System (INIS)

    Fischer, W.

    1995-12-01

    Nonlinear magnetic fields in conjunction with tune modulation may lead to chaotic particle motion and thereby limit the dynamic aperture in hadron storage rings. This is on particular interest for high energy storage rings with superconducting magnets at injection energy where magnetic field errors and the beam size have their maximum values. At the CERN SPS a dynamic aperture experiment was performed with the aim of finding the relevant effects for the stability of single particle motion in hadron storage rings. Experimental results are compared to long-term particle tracking to test to which extent computer programs can predict the dynamic aperture under well known conditions. In addition, detailed investigations of the loss mechanisms were pursued to improve the phenomenological understanding of the intricate details of particle motion in phase space. In a complementary experiment at the HERA proton ring at injection energy the dynamic aperture was measured under normal operating conditions. The computer simulations for these measurements included a very detailed model of the nonlinear fields which were measured for each individual magnet. Simulation results for the LHC are shown that estimate the effect of tune ripple of different strength on the dynamic aperture for different sets of random nonlinear field errors. (orig.)

  3. Split ring containment attachment device

    International Nuclear Information System (INIS)

    Sammel, A.G.

    1996-01-01

    A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

  4. An N-body Integrator for Planetary Rings

    Science.gov (United States)

    Hahn, Joseph M.

    2011-04-01

    A planetary ring that is disturbed by a satellite's resonant perturbation can respond in an organized way. When the resonance lies in the ring's interior, the ring responds via an m-armed spiral wave, while a ring whose edge is confined by the resonance exhibits an m-lobed scalloping along the ring-edge. The amplitude of these disturbances are sensitive to ring surface density and viscosity, so modelling these phenomena can provide estimates of the ring's properties. However a brute force attempt to simulate a ring's full azimuthal extent with an N-body code will likely fail because of the large number of particles needed to resolve the ring's behavior. Another impediment is the gravitational stirring that occurs among the simulated particles, which can wash out the ring's organized response. However it is possible to adapt an N-body integrator so that it can simulate a ring's collective response to resonant perturbations. The code developed here uses a few thousand massless particles to trace streamlines within the ring. Particles are close in a radial sense to these streamlines, which allows streamlines to be treated as straight wires of constant linear density. Consequently, gravity due to these streamline is a simple function of the particle's radial distance to all streamlines. And because particles are responding to smooth gravitating streamlines, rather than discrete particles, this method eliminates the stirring that ordinarily occurs in brute force N-body calculations. Note also that ring surface density is now a simple function of streamline separations, so effects due to ring pressure and viscosity are easily accounted for, too. A poster will describe this N-body method in greater detail. Simulations of spiral density waves and scalloped ring-edges are executed in typically ten minutes on a desktop PC, and results for Saturn's A and B rings will be presented at conference time.

  5. 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

  6. Electro-optical hybrid slip ring

    Science.gov (United States)

    Hong, En

    2005-11-01

    The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

  7. Photochemistry in Saturn’s Ring-Shadowed Atmosphere: Modulation of Hydrocarbons and Aerosols

    Science.gov (United States)

    Edgington, Scott G.; Atreya, Sushil K.; Wilson, Eric H.; Baines, Kevin H.; West, Robert A.; Bjoraker, Gordon L.; Fletcher, Leigh N.; Momary, Tom

    2015-11-01

    Cassini has been orbiting Saturn for over eleven years now. During this epoch, the ring shadow has moved from covering much of the northern hemisphere (the solar inclination was 24 degrees) to covering a large swath south of the equator and it continues to move southward. At Saturn Orbit Insertion in 2004, the projection of the A-ring onto Saturn reached as far as 40N along the central meridian (52N at the terminator). At its maximum extent, the ring shadow can reach as far as 48N/S (58N/S at the terminator). The net effect is that the intensity of both ultraviolet and visible sunlight penetrating through the rings to any particular latitude will vary depending on both Saturn’s axis relative to the Sun and the optical thickness of each ring system. In essence, the rings act like semi-transparent venetian blinds.Our previous work, examined the variation of the solar flux as a function of solar inclination, i.e. for each 7.25-year season at Saturn. Here, we report on the impact of the oscillating ring shadow on the photolysis and production rates of hydrocarbons (acetylene, ethane, propane, and benzene) and phosphine in Saturn’s stratosphere and upper troposphere. The impact of these production and loss rates on the abundance of long-lived photochemical products leading to haze formation are explored. Similarly, we assess their impact on phosphine abundance, a disequilibrium species whose presence in the upper troposphere can be used as a tracer of convective processes in the deeper atmosphere.We will also present our ongoing analysis of Cassini’s datasets that provide an estimate of the evolving haze content of the northern hemisphere and we will begin to assess the implications for dynamical mixing. In particular, we will examine how the now famous hexagonal jet stream acts like a barrier to transport, isolating Saturn’s north polar region from outside transport of photochemically-generated molecules and haze.The research described in this paper was carried

  8. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

    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.

  9. Synthesis of 5-Substituted 3-Amino-1H-Pyrazole-4-Carbonitriles as Precursors for Microwave Assisted Regiospecific Syntheses of Pyrazolo[1,5-a]Pyrimidines

    Directory of Open Access Journals (Sweden)

    Fawzia Al-Qalaf

    2008-12-01

    Full Text Available A simple route to 3-oxoalkanonitrile 5, aprecursor of the title compounds is described. Reaction of enaminones 2 with hydroxylamine hydrochloride in ethanol yielded aldoximes 3 that were converted readily into 5 in basic medium. This method has been successfully applied with a number of substrates and resulted in excellent yields of the products. Reacting 5 with trichloroacetonitrile afforded 3-amino-2-aroyl-4,4,4-trichloro-2-butenenitriles 6 that condensed with hydrazines to yield 3-amino-1H-pyrazole-4-carbonitrilederivatives 8. Substituted pyrazolo[1,5-a]pyridmidines have been prepared with regioselective condensation reactions of 8 with nonsymmetrical dielectrophiles. The structures of compounds obtained were deduced based on 1H-NMR, 1H-15N HMBC- measurements.

  10. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    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 [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

  11. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

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

  12. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  13. 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...

  14. The Lord of Rings - the mysterious case of the stolen rings: a critical analysis

    Science.gov (United States)

    Sandrelli, S.

    The Lord of Rings - the mysterious case of the stolen rings: a critical analysis S. Sandrelli INAF - Osservatorio Astronomico di Brera, Milano, Italy (stefano.sandrelli@brera.inaf.it / Fax: 02 72001600 / Phone: +39 02 72320337) "The Lord of Rings - the mysterious case of the stolen rings" is a live astronomical role-playing game for kids aged 10 -13. Its goal is to introduce them to some of the main topics of the Solar System: a) the role of gravity; b) the distribution of mass & light; c) the effects of rotation; d) the distribution of water. The game was held both at the Perugia (2004) and the Genova Science Festival (2005), obtaining great success. Teams of about 6-8 members are introduced to Mr Schioppanelli, the astro-detective of the town (the name is a pun: it reminds Schiaparelli, the famous italian astronomer, and it is a slang expression meaning "ring-breaker"). Mr Schioppanelli has his office in an "gastronomical astronomical observatory", known as The Red Giant Pizzeria. Schioppanelli informs the kids that a mysterious Centaur succeded in stealing the rings of Saturn. The partecipants are appointed astro-detectives in-charge and asked to find the rings by browsing around the Solar System, which is scaled so as to fit the town historical centre or a pedestrian area, going from the Sun to Saturn or beyond, depending on the actual area at disposal. Great care must be taken allowing children playing only in a car-free area of the town. At the right scaled distances, the partecipants meet characters playing as the various planets. The kids can talk to them after solving a riddle, obtaining useful informations. A special characters play as a comet, timely going in and out of the inner solar system. The teams can also talk to some shepherd-moons of the rings. They easily discover that the rings were totally destroyed by the Centaur: a real disaster! They are also suggested to gather the necessary ingredients (gravity, light, rotation, inclination, dust and

  15. Optimal fold symmetry of LH2 rings on a photosynthetic membrane.

    Science.gov (United States)

    Cleary, Liam; Chen, Hang; Chuang, Chern; Silbey, Robert J; Cao, Jianshu

    2013-05-21

    An intriguing observation of photosynthetic light-harvesting systems is the N-fold symmetry of light-harvesting complex 2 (LH2) of purple bacteria. We calculate the optimal rotational configuration of N-fold rings on a hexagonal lattice and establish two related mechanisms for the promotion of maximum excitation energy transfer (EET). (i) For certain fold numbers, there exist optimal basis cells with rotational symmetry, extendable to the entire lattice for the global optimization of the EET network. (ii) The type of basis cell can reduce or remove the frustration of EET rates across the photosynthetic network. We find that the existence of a basis cell and its type are directly related to the number of matching points S between the fold symmetry and the hexagonal lattice. The two complementary mechanisms provide selection criteria for the fold number and identify groups of consecutive numbers. Remarkably, one such group consists of the naturally occurring 8-, 9-, and 10-fold rings. By considering the inter-ring distance and EET rate, we demonstrate that this group can achieve minimal rotational sensitivity in addition to an optimal packing density, achieving robust and efficient EET. This corroborates our findings i and ii and, through their direct relation to S, suggests the design principle of matching the internal symmetry with the lattice order.

  16. Vortex rings in classical and quantum systems

    International Nuclear Information System (INIS)

    Barenghi, C F; Donnelly, R J

    2009-01-01

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

  17. Solvent extraction of Zr(IV) and Nb(V) with 1-phenyl-3-methyl-4benzoyl-pyrazole-5-one and tri-iso-octylamine from different mineral acid solutions

    International Nuclear Information System (INIS)

    Mirza, M.Y.; Nwabue, F.I.; Ahmed, S.

    1981-01-01

    The extraction of Zr(IV) and Nb(V) from aqueous solutions of mineral acids with 1% 1-phenyl-3-methyl-4-benzoyl-pyrazole-5-one and 5% tri-iso-octylamine solutions in chloroform has been investigated respectively. The mechanism of extraction and the composition of the extracted species have been suggested and the effect of complexing and salting-out agents also determined. Separation factors of various metals with respect to niobium have been estimated and separation from zirconium and many other elements has been achieved. Procedures are recommended for the separation of 95 Nb from 95 Zr- 95 Nb mixture as well as from the fission products. (orig.) [de

  18. Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774-775

    Science.gov (United States)

    Rakowski, Andrzej Z.; Krąpiec, Marek; Huels, Mathias; Pawlyta, Jacek; Dreves, Alexander; Meadows, John

    2015-10-01

    Evidence of a rapid increase in atmospheric radiocarbon (14C) content in AD 774-775 was presented by Miyake et al. (2012), who observed an increase of about 12‰ in the 14C content in annual tree rings from Japanese cedar. Usoskin et al. (2013) report a similar 14C spike in German oak, and attribute it to exceptional solar activity. If this phenomenon is global in character, such rapid changes in 14C concentration may affect the accuracy of calibrated dates, as the existing calibration curve is composed mainly of decadal samples. Single-year samples of dendro-chronologically dated tree rings of deciduous oak (Quercus robur) from Kujawy, a village near Krakow (SE Poland), spanning the years AD 765-796, were collected and their 14C content was measured using the AMS system in the Leibniz Laboratory. The results clearly show a rapid increase of 9.2 ± 2.1‰ in the 14C concentration in tree rings between AD 774 and AD 775, with maximum Δ14C = 4.1 ± 2.3‰ noted in AD 776.

  19. Laparoscopic appendicectomy using endo-ring applicator and fallope rings

    International Nuclear Information System (INIS)

    Ali, Iyoob V; Maliekkal, Joji I

    2009-01-01

    Wider adoption of laparoscopic appendicectomy (LA) is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Twenty-five patients who were candidates for appendicectomy (emergency as well as elective) and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. The procedure was successful in 23 (92%) cases, and the mean duration of the procedure was 20 minutes (15-32 minutes). There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method. (author)

  20. 5-(4-Ethoxyphenyl-3-(pyridin-2-yl-4,5-dihydro-1H-pyrazole-1-carbothioamide

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2012-03-01

    Full Text Available In the title compound, C17H18N4OS, a pyrazoline derivative, the pyrazoline ring adopts an envelope conformation with the C atom bonded to the benzene ring as the flap atom. The dihedral angle between the pyridine and benzene rings is 80.50 (6°. The ethoxyphenyl group is approximately planar, with an r.m.s. deviation of 0.0238 (1 Å for the nine non-H atoms. In the crystal, molecules are linked by N—H...O and N—H...S hydrogen bonds into a tape along the b axis. Weak C—H...N and C—H...π interactions are also observed.

  1. SMARANDACHE NON-ASSOCIATIVE RINGS

    OpenAIRE

    Vasantha, Kandasamy

    2002-01-01

    An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...

  2. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  3. Gear Tooth Root Stresses of a Very Heavily Loaded Gear Pair-Case Study: Orbiter Body Flap Actuator Pinion and Ring Gear

    Science.gov (United States)

    Krantz, Timothy L.; Handschuh, Robert F.

    2015-01-01

    The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.

  4. 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.)

  5. Tinkering at the main-ring lattice

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, S.

    1982-08-23

    To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.

  6. The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy

    OpenAIRE

    Schurmans, C?line; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Th?r?se; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

    2015-01-01

    Background Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV a...

  7. Synthesis of Novel β-Keto-Enol Derivatives Tethered Pyrazole, Pyridine and Furan as New Potential Antifungal and Anti-Breast Cancer Agents

    Directory of Open Access Journals (Sweden)

    Smaail Radi

    2015-11-01

    Full Text Available Recently, a new generation of highly promising inhibitors bearing β-keto-enol functionality has emerged. Reported herein is the first synthesis and use of novel designed drugs based on the β-keto-enol group embedded with heterocyclic moieties such as pyrazole, pyridine, and furan, prepared in a one-step procedure by mixed Claisen condensation. All the newly synthesized compounds were characterized by FT-IR, 1H-NMR, 13C-NMR, ESI/LC-MS, elemental analysis, and evaluated for their in vitro antiproliferative activity against breast cancer (MDA-MB241 human cell lines and fungal strains (Fusarium oxysporum f.sp albedinis FAO. Three of the synthesized compounds showed potent activity against fungal strains with IC50 values in the range of 0.055–0.092 µM. The results revealed that these compounds showed better IC50 values while compared with positive controls.

  8. Electron impact single detachment on the F- ions using the heavy ion storage ring CRYRING: cross-section determination

    International Nuclear Information System (INIS)

    Andersson, K.; Hanstorp, D.; Oesterdahl, F.; Danared, H.; Kaellberg, A.

    2001-01-01

    Electron Impact Single Detachment (EISD) of F - has been studied using the heavy ion storage ring CRYRING at the Manne Siegbahn Laboratory, Stockholm, Sweden. F - ions stored in the ring were merged with an electron beam in one of the ring sections. Neutral F atoms produced in the EISD process were detected in the zero-degree direction using a surface barrier detector. The threshold for the detachment process was found to be around 7.6 eV, thus more than twice the binding energy of F - . The cross-sections increased smoothly up to 55 eV where it reached a maximum of 1.9 x 10 -16 cm 2 . At higher energies a slow decrease of the cross-section was observed, which follows the energy dependence predicted by the Bethe-Born approximation. The experiment showed that CRYRING can be used favourably for studies of anions, and several experiments are forthcoming. (orig.)

  9. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

  10. Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring

    International Nuclear Information System (INIS)

    Tanabe, Tetsumi

    2006-01-01

    At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)

  11. Leapfrogging of multiple coaxial viscous vortex rings

    International Nuclear Information System (INIS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2015-01-01

    A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior

  12. Redox shuttles having an aromatic ring fused to a 1,1,4,4-tetrasubstituted cyclohexane ring

    Science.gov (United States)

    Weng, Wei; Zhang, Zhengcheng; Amine, Khalil

    2015-12-01

    An electrolyte includes an alkali metal salt; an aprotic solvent; and a redox shuttle additive including an aromatic compound having at least one aromatic ring fused with at least one non-aromatic ring, the aromatic ring having two or more oxygen or phosphorus-containing substituents.

  13. 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.

  14. Magnetic ring for stripping enhancement

    International Nuclear Information System (INIS)

    Selph, F.

    1992-10-01

    A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

  15. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  16. Temporal variation of tritium concentration in tree-ring cellulose over the past 50 years

    International Nuclear Information System (INIS)

    Yamada, Y.; Yasuike, K.; Komura, K.

    2004-01-01

    Concentration of organically-bound tritium in the tree-ring cellulose of a pine tree grown in Shika-machi, Ishikawa prefecture, Japan (37.1degN, 136.5degE), was measured during the ring-years from 1949 to 1999. The results were compared with those of a pine tree grown in Tatsunokuchi-machi, Ishikawa prefecture, Japan (36.4degN, 136.5degE). The annual variation of tritium in tree rings demonstrated two differences between the Shika-machi tree and the Tatsunokuchi-machi tree. No secondary peak appeared in the period after the maximum peak of 1963 for the Shika-machi tree, while two peaks appeared in 1966 and 1970 for the Tatsunokuchi-machi tree. In addition, the height of the 1963 peak was 30% higher for the Shika-machi tree than for the Tatsunokuchi-machi tree. These differences are considered to be caused by the influence that the underground water in the root zone of the Tatsunokuchi-machi tree was strongly affected by water which was transported to the tree site from mountain regions as compared to the Shika-machi tree. (author)

  17. A first course in noncommutative rings

    CERN Document Server

    Lam, T Y

    2001-01-01

    A First Course in Noncommutative Rings, an outgrowth of the author's lectures at the University of California at Berkeley, is intended as a textbook for a one-semester course in basic ring theory. The material covered includes the Wedderburn-Artin theory of semisimple rings, Jacobson's theory of the radical, representation theory of groups and algebras, prime and semiprime rings, local and semilocal rings, perfect and semiperfect rings, etc. By aiming the level of writing at the novice rather than the connoisseur and by stressing th the role of examples and motivation, the author has produced a text that is suitable not only for use in a graduate course, but also for self- study in the subject by interested graduate students. More than 400 exercises testing the understanding of the general theory in the text are included in this new edition.

  18. Thermometric Study of Inhibition of Aluminium Corrosion in Hydrochloric Acid Solution

    OpenAIRE

    Al Gaber, A.S. [امينة سلطان الجابر; Seliman, S. A.; Mourad, M.

    1997-01-01

    The use of 6- amino - 4- (4-phenyl)-l,4- dihydro -3- methylpyrano [2,3- c] pyrazole -5- carbonitrile and some related compounds as corrosion inhibitors for aluminium in 2 M HCl solution was studied by the thermometric method. The results indicate that the additives reduce the corrosion rate via weak adsorption through the cationic oxygen of the pyran ring. They act as mixed inhibitors and their adsorption was found to obey Frumkin's isotherm. The inhibition efficiency of the additives is rela...

  19. Bacterial biomass in warm-core Gulf Stream ring 82-B: mesoscale distributions, temporal changes and production

    Science.gov (United States)

    Ducklow, Hugh

    1986-11-01

    The distribution of bacterioplankton biomass and productivity in warm-core Gulf Stream ring 82-B generally corresponded to the physical and dynamical structure of the ring. Mean cell volumes were uniform for 4 months, but were larger by a factor of 2-3 in the high velocity (frontal) region (HVR) near the ring edge. As a result of this gradient and higher abundances, water column biomass and production were highest in the front, which appeared to be a local maximum in those properties. In this regard bacterioplankton contrasted strongly to phytoplankton, which exhibited strong local maxima at the center of the ring in June. In April when the water column inside the ring was isothermal to 450 m, bacterial biomass and production were low and uniform to 250 and 50 m, respectively. Bacterioplankton responded dramatically to the vernal restratification of the ring. In June when the surface layer was characterized by a strong pycnocline at 10-40 m, bacterial biomass and production often had strong subsurface maxima, and were 3 and 5 times greater than in April, respectively. Abundance exceeded 1.5 × 10 9 cells l -1 at ring center and exceeded 3 × 10 9 l -1 in the HVR. Turnover rates for the euphotic zone bacterioplankton as a whole were 0.24 d -1 in April, 0.56 d -1 in June, and 0.27 d -1 in August at ring center. Bacterial production averaged 12% of hourly primary production (range 1-32%), suggesting that bacteria control a significant and sometimes large portion of the carbon cycling in the euphotic zone. These data suggest that warm-core rings are sites of enhanced variability of bacterioplankton properties in the open sea. Furthermore, the data strongly support recent work showing that frontal zones are sites of locally enhanced bacterial biomass and production. In the ring system as a whole, the euphotic zone bacterioplankton biomass and production were comparable to and occasionally greater than the biomass and production of the >64 μm zooplankton, especially in

  20. Design of Piston Ring Friction Tester Apparatus

    DEFF Research Database (Denmark)

    Klit, Peder

    2006-01-01

    One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...

  1. Study for ILC Damping Ring at KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

    2011-11-04

    ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

  2. Planetary ring systems properties, structures, and evolution

    CERN Document Server

    Murray, Carl D

    2018-01-01

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

  3. Longitudinal beam instability due to the ring impedance at KEK's accelerator test facility damping ring

    International Nuclear Information System (INIS)

    Kim, Eun-San

    2003-01-01

    This paper shows the results of a numerical study of the impedance in the Accelerator Test Facility damping ring. The longitudinal impedance in the damping ring is shown to be inductive. It is shown that the total impedance |Z || /n| is 0.23 Ω and the inductance is L = 14 nH. In the extremely low emittance beam of the damping ring, bunch lengthening is caused by both the effects of potential-well distortion and intra-beam scattering. In this paper, the bunch-lengthening due to the ring impedance is numerically investigated, and the result shows qualitative agreement with the result of an analysis performed using the bunch-length measurement. With the calculated longitudinal impedance, the instability threshold in the damping ring is estimated to be a bunch population of 3.3 x 10 10 by using both a Vlasov equation approach and a multi-particle tracking method.

  4. 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

  5. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

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

  6. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

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

    2010-01-01

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

  7. Quality Assurance Project Plan for Verification of Sediment Ecotoxicity Assessment Ring(SEA Ring)

    Science.gov (United States)

    The objective of the verification is to test the efficacy and ability of the Sediment Ecotoxicity Assessment Ring (SEA Ring) to evaluate the toxicity of contaminants in the sediment, at the sediment-water interface, and WC to organisms that live in those respective environments.

  8. Dynamical Evolution of Ring-Satellite Systems

    Science.gov (United States)

    Ohtsuki, Keiji

    2005-01-01

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

  9. A novel tubular linear motor equipped with radially anisotropic NdFeB ring magnets

    International Nuclear Information System (INIS)

    Hor, P.J.

    1998-01-01

    The paper describes the design synthesis and optimisation of a novel tubular linear motor employing radially magnetised anisotropic ring magnets. Design issues, related to optimising the dimensions for maximum acceleration capability, minimum cogging force and low harmonic distortion in the emf waveform, are discussed. The influence of inhomogeneities in the magnets on the performance of a prototype motor is discussed, and its dynamic performance is validated experimentally against a typical target specification for automated high-speed manufacturing applications. (orig.)

  10. Propellers in Saturn's rings

    Science.gov (United States)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

  11. Cosmic rings from colliding galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Mitton, S

    1976-11-18

    Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  13. 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.

  14. WE-A-17A-05: Differences in Applicator Configuration and Dwell Loading Between Standard and Image-Guided Tandem and Ring (T and R) HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Damato, A; Cormack, R; Bhagwat, M; Buzurovic, I; Lee, L; Viswanathan, A [Brigham and Women' s Hospital, Boston, MA (United States)

    2014-06-15

    Purpose: To investigate differences in: (i) relative location of the tandem and the ring compared to a rigid standard applicator model; and (ii) relative loading and changes in loading pattern between standard and image-guided planning. Methods: All T and R insertions performed in 2013 in our institution under CT- or MR-guidance were analyzed. Standard plans were generated using library applicator models with a fixed relationship between ring and tandem, standardized uniform dwell loading and normalization to point A. The graphic plans and the associated standard-plan dwell configurations were compared: the rings were rigidly registered, and the residual tandem shift, rotation and maximum distance between plan tandem dwell and corresponding model tandem dwell were calculated. The normalization ratio (NR = the ratio of graphic versus standard-plan total reference air kerma [TRAK]), the general loading difference (GLD = the difference between graphic and standard ratios of the tandem versus the ring TRAK), and the percent standard deviation (SD% = SD/mean) of the tandem and the ring TRAK for the graphic plan (all standard-plans SD% = 0) were calculated. Results: 71 T and R were analyzed. Residual tandem shift, rotation and maximum corresponding dwell distance were 1.2±0.8mm (0.4±0.4mm lateral, 0.9±0.8mm craniocaudal, 0.4±0.3mm anterior-posterior), 2.3±1.9deg and 3.4±2.3mm. NR was 0.86±0.11 indicating a lower overall loading of the graphic compared to the standard plans. GLD was -0.12±0.16 indicating a modest increased ring loading relative to the tandem in the graphic plans. SD% was 2.1±1.6% for tandem and 2.8±1.9% for ring, indicating small deviations from uniform loading. Conclusion: Variability in the relative locations of the tandem and the ring necessitates the independent registration of each component model for accurate digitization. Our clinical experience suggests that graphically planned T and R results on average in a lower total dose to the

  15. WE-A-17A-05: Differences in Applicator Configuration and Dwell Loading Between Standard and Image-Guided Tandem and Ring (T and R) HDR Brachytherapy

    International Nuclear Information System (INIS)

    Damato, A; Cormack, R; Bhagwat, M; Buzurovic, I; Lee, L; Viswanathan, A

    2014-01-01

    Purpose: To investigate differences in: (i) relative location of the tandem and the ring compared to a rigid standard applicator model; and (ii) relative loading and changes in loading pattern between standard and image-guided planning. Methods: All T and R insertions performed in 2013 in our institution under CT- or MR-guidance were analyzed. Standard plans were generated using library applicator models with a fixed relationship between ring and tandem, standardized uniform dwell loading and normalization to point A. The graphic plans and the associated standard-plan dwell configurations were compared: the rings were rigidly registered, and the residual tandem shift, rotation and maximum distance between plan tandem dwell and corresponding model tandem dwell were calculated. The normalization ratio (NR = the ratio of graphic versus standard-plan total reference air kerma [TRAK]), the general loading difference (GLD = the difference between graphic and standard ratios of the tandem versus the ring TRAK), and the percent standard deviation (SD% = SD/mean) of the tandem and the ring TRAK for the graphic plan (all standard-plans SD% = 0) were calculated. Results: 71 T and R were analyzed. Residual tandem shift, rotation and maximum corresponding dwell distance were 1.2±0.8mm (0.4±0.4mm lateral, 0.9±0.8mm craniocaudal, 0.4±0.3mm anterior-posterior), 2.3±1.9deg and 3.4±2.3mm. NR was 0.86±0.11 indicating a lower overall loading of the graphic compared to the standard plans. GLD was -0.12±0.16 indicating a modest increased ring loading relative to the tandem in the graphic plans. SD% was 2.1±1.6% for tandem and 2.8±1.9% for ring, indicating small deviations from uniform loading. Conclusion: Variability in the relative locations of the tandem and the ring necessitates the independent registration of each component model for accurate digitization. Our clinical experience suggests that graphically planned T and R results on average in a lower total dose to the

  16. Modeling of lipase catalyzed ring-opening polymerization of epsilon-caprolactone.

    Science.gov (United States)

    Sivalingam, G; Madras, Giridhar

    2004-01-01

    Enzymatic ring-opening polymerization of epsilon-caprolactone by various lipases was investigated in toluene at various temperatures. The determination of molecular weight and structural identification was carried out with gel permeation chromatography and proton NMR, respectively. Among the various lipases employed, an immobilized lipase from Candida antartica B (Novozym 435) showed the highest catalytic activity. The polymerization of epsilon-caprolactone by Novozym 435 showed an optimal temperature of 65 degrees C and an optimum toluene content of 50/50 v/v of toluene and epsilon-caprolactone. As lipases can degrade polyesters, a maximum in the molecular weight with time was obtained due to the competition of ring opening polymerization and degradation by specific chain end scission. The optimum temperature, toluene content, and the variation of molecular weight with time are consistent with earlier observations. A comprehensive model based on continuous distribution kinetics was developed to model these phenomena. The model accounts for simultaneous polymerization, degradation and enzyme deactivation and provides a technique to determine the rate coefficients for these processes. The dependence of these rate coefficients with temperature and monomer concentration is also discussed.

  17. On Semiprime Noetherian PI-Rings

    OpenAIRE

    Chiba, Katsuo

    2000-01-01

    Let R be a semiprime Noetherian PI-ring and Q(R) the semisimple Artinian ring of fractions of R. We shall prove the following conditions are equivalent: (1) the Krull dimention of R is at most one, (2) Any ring between R and Q(R) is again right Noetherian, (3) Let a, b be central regular elements of Q(R). Then the subring R + aR[b] of Q(R) is right Noetherian.

  18. On zero divisor graph of unique product monoid rings over Noetherian reversible ring

    Directory of Open Access Journals (Sweden)

    Ebrahim Hashemi

    2016-02-01

    Full Text Available Let $R$ be an associative ring with identity and $Z^*(R$ be its set of non-zero zero divisors.  The zero-divisor graph of $R$, denoted by $Gamma(R$, is the graph whose vertices are the non-zero  zero-divisors of  $R$, and two distinct vertices $r$ and $s$ are adjacent if and only if $rs=0$ or $sr=0$.  In this paper, we bring some results about undirected zero-divisor graph of a monoid ring over reversible right (or left Noetherian ring $R$. We essentially classify the diameter-structure of this graph and show that $0leq mbox{diam}(Gamma(Rleq mbox{diam}(Gamma(R[M]leq 3$. Moreover, we give a characterization for the possible diam$(Gamma(R$ and diam$(Gamma(R[M]$, when $R$ is a reversible Noetherian ring and $M$ is a u.p.-monoid. Also, we study relations between the girth of $Gamma(R$ and that of $Gamma(R[M]$.

  19. Imidazolopiperazines (IPZ) kill both rings and dormant rings in wild type and K13 artemisinin resistant Plasmodium falciparum in vitro.

    Science.gov (United States)

    Dembele, Laurent; Gupta, Devendra Kumar; Lim, Michelle Yi-Xiu; Ang, Xiaoman; Selva, Jeremy J; Chotivanich, Kesinee; Nguon, Chea; Dondorp, Arjen M; Bonamy, Ghislain M C; Diagana, Thierry T; Bifani, Pablo

    2018-03-12

    Artemisinin (ART) resistance has spread through Southeast Asia, posing serious threat to the control and elimination of malaria. ART resistance has been associated with mutations in the Plasmodium falciparum kelch-13 ( Pfk13 ) propeller domain. Phenotypically, ART resistance is defined as delayed parasite clearance in patients' due to the reduced susceptibility of early ring-stage parasites to the active metabolite of ART dihydroartemisinin (DHA). Early rings can enter a state of quiescence upon DHA exposure and resume growth in its absence. These quiescent rings are referred to as dormant rings or DHA-pretreated rings (called here dormant rings). The imidazolopiperazine (IPZ) is a novel class of antimalarial drugs, which has demonstrated efficacy in early clinical trials. Here, we characterized the stage of action of IPZ GNF179 and evaluated its activity against rings and dormant rings in wild type and ART resistant parasites. Unlike DHA, GNF179 does not induce dormancy. We show that GNF179 is more rapidly cidal against schizonts than ring and trophozoite stages. However, with 12 hours exposure, the compound effectively kills rings and dormant rings of both susceptible and ART resistant parasites within 72 hours. We further demonstrate that in combination with ART, GNF179 effectively prevent recrudescence of dormant rings including those bearing pfk13 propeller mutations. Copyright © 2018 Dembele et al.

  20. Complete snake and rotator schemes for spin polarization in proton rings and large electron rings

    International Nuclear Information System (INIS)

    Steffen, K.

    1983-11-01

    In order to maintain spin polarization in proton rings and large electron rings, some generalized Siberian Snake scheme may be required to make the spin tune almost independent of energy and thus avoid depolarizing resonances. The practical problem of finding such schemes that, at reasonable technical effort, can be made to work over large energy ranges has been addressed before and is here revisited in a broadened view and with added new suggestions. As a result, possibly optimum schemes for electron rings (LEP) and proton rings are described. In the proposed LEP scheme, spin rotation is devised such that, at the interaction points, the spin direction is longitudinal as required for experiments. (orig.)

  1. [Tree-ring growth responses of Mongolian oak (Quercus mongolica) to climate change in southern northeast: a case study in Qianshan Mountains].

    Science.gov (United States)

    Teng, Li; Xing-Yuan, He; Zhen-Ju, Chen

    2014-07-01

    Mongolian oak is one of the most important broad-leaved tree species in forests, Northeast China. Based on the methodology of dendrochronology, the variations of tree ring radial growth of Mongolian oak in Qianshan Mountains, south of Northeast China, were analyzed. Combined with the temperature and precipitation data from meteorological stations since 1951, the relationships between standardized tree ring width chronology and main climatic factors were analyzed. In this region, the precipitation between April and July of the current year had an significant relationship with the tree ring width of Mongolian oak, and was the main factor limiting the radial growth. The extreme maximum temperature of May was also a key factor influencing the tree ring width, which had a significant on the tree ring width of Mongolian oak. The precipitation in April had a significant and stable relationship with the growth of Mongolian oak since the 1950s. The 'divergence problem' was found in the study area, which the sensitivity of tree growth to summer temperature reduced since the 1980s. The tree growth response to temperature showed a seasonal change from summer to spring.

  2. Synthesis, structural characterization and theoretical studies of a new Schiff base 4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl) imino)methyl)phenol

    Science.gov (United States)

    Cuenú, Fernando; Londoño-Salazar, Jennifer; Torres, John Eduard; Abonia, Rodrigo; D'Vries, Richard F.

    2018-01-01

    4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl)imino)methyl)phenol (4-OHFPz) was synthesized and characterized by FT-IR, MS, NMR, and single-crystal X-ray diffraction. Optimization of molecular geometry, vibrational frequencies, and chemical shifts were calculated by using the methods of density functional theory (DFT) with B3LYP and B3PW91 as functionals and Hartree-Fock with 6-311G++(d,p) as basis set using the GAUSSIAN 09 program package. With the VEDA 4 software, the vibrational frequencies were assigned in terms of the potential energy distribution (PED). The equilibrium geometries calculated by all methods were compared with X-ray diffraction results, indicating that the theoretical results matches well with the experimental ones. The data obtained from the vibrational analysis and the calculated NMR are consistent with the experimental spectra.

  3. Simple and Efficient One-Pot Synthesis, Spectroscopic Characterization and Crystal Structure of Methyl 5-(4-Chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Imtiaz Khan

    2012-07-01

    Full Text Available A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy-1-phenyl-1H-pyrazole-3-carboxylate (4 is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was deduced by modern spectroscopic and analytical techniques and unequivocally confirmed by a single crystal X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P 21 21 21 with cell parameters a = 6.6491(3 Å, b = 7.9627(6 Å, c = 30.621(5 Å, α = β = γ = 90° and Z = 4. The crystal packing of the compound (4 is stabilized by an offset π-stacking between the planar benzoyl-substituted diazole moieties.

  4. Tens of GHz Tantalum pentoxide-based micro-ring all-optical modulator for Si photonics

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chung-Lun; Chi, Wen-Chun; Chiu, Yi-Jen; Lin, Yuan-Yao; Hung, Yung-Jr; Chu, Ann-Kuo [Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Hsieh, Cheng-Hsuan; Lin, Gong-Ru [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei (China); Shih, Min-Hsiung [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan (China); Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Lee, Chao-Kuei [Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan (China); Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan (China)

    2017-03-15

    A tantalum pentoxide-based (Ta{sub 2}O{sub 5}-based) micro-ring all-optical modulator was fabricated. The refractive index inside the micro-ring cavity was modified using the Kerr effect by injecting a pumped pulse. The transmittance of the ring resonator was controlled to achieve all-optical modulation at the wavelength of the injected probe. When 12 GHz pulses with a peak power of 1.2 W were coupled in the ring cavity, the transmission spectrum of the Ta{sub 2}O{sub 5} resonator was red-shifted by 0.04 nm because of the Kerr effect. The relationship between the modulation depth and gap of the Ta{sub 2}O{sub 5} directional coupler is discussed. An optimized gap of 1100 nm was obtained, and a maximum buildup factor of 11.7 with 84% modulation depth was achieved. The nonlinear refractive index of Ta{sub 2}O{sub 5} at 1.55 μm was estimated as 3.4 x 10{sup -14} cm{sup 2}/W based on the Kerr effect, which is almost an order of magnitude higher than that of Si{sub 3}N{sub 4}. All results indicate that Ta{sub 2}O{sub 5} has potential for use in nonlinear waveguide applications with modulation speeds as high as tens of GHz. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Koffka's Ring Effect Depends on Thickness, Not Continuity

    OpenAIRE

    Abigail E. Huang; Alice J. Hon; Eric L. Altschuler

    2007-01-01

    More than 70 years ago Gestalt psychologist Kurt Koffka described a fascinating effect1,2: When a contiguous grey ring is placed on a background half of one shade of grey (different from the ring) and half of another shade of grey, the ring appears to be a homogenous. However, if the ring is slightly divided, now the two halves of the ring appear different shades of grey with the half of the ring on the darker background appearing lighter than the half of the ring on the darker background. Th...

  6. Persistent current of relativistic electrons on a Dirac ring in presence of impurities

    KAUST Repository

    Ghosh, Sumit; Saha, Arijit

    2014-01-01

    We study the behaviour of persistent current of relativistic electrons on a one dimensional ring in presence of attractive/repulsive scattering potentials. In particular, we investigate the persistent current in accordance with the strength as well as the number of the scattering potential. We find that in presence of single scatterer the persistent current becomes smaller in magnitude than the scattering free scenario. This behaviour is similar to the non-relativistic case. Even for a very strong scattering potential, finite amount of persistent current remains for a relativistic ring. In presence of multiple scatterer we observe that the persistent current is maximum when the scatterers are placed uniformly compared to the current averaged over random configurations. However if we increase the number of scatterers, we find that the random averaged current increases with the number of scatterers. The latter behaviour is in contrast to the non-relativistic case. © 2014 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

  7. Persistent current of relativistic electrons on a Dirac ring in presence of impurities

    KAUST Repository

    Ghosh, Sumit

    2014-08-01

    We study the behaviour of persistent current of relativistic electrons on a one dimensional ring in presence of attractive/repulsive scattering potentials. In particular, we investigate the persistent current in accordance with the strength as well as the number of the scattering potential. We find that in presence of single scatterer the persistent current becomes smaller in magnitude than the scattering free scenario. This behaviour is similar to the non-relativistic case. Even for a very strong scattering potential, finite amount of persistent current remains for a relativistic ring. In presence of multiple scatterer we observe that the persistent current is maximum when the scatterers are placed uniformly compared to the current averaged over random configurations. However if we increase the number of scatterers, we find that the random averaged current increases with the number of scatterers. The latter behaviour is in contrast to the non-relativistic case. © 2014 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.

  8. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  9. IAG ring test animal proteins 2014

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Voet, van der H.; Vliege, J.J.M.

    2014-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG – International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The aim of the ring study was to provide the participants

  10. IAG ring test animal proteins 2015

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.E.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2015-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the ring test was RIKILT - Wageningen UR, The

  11. IAG ring test animal proteins 2013

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Pinckaers, V.G.Z.; Scholtens-Toma, I.M.J.; Prins, T.W.; Vliege, J.J.M.

    2013-01-01

    A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the the ring study was to provide the

  12. Cooling rings for TeV colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1985-02-01

    Consideration is given to quantum fluctuations, intra beam scattering, cooling rates, and ring acceptance in order to see if one can obtain a normalized emittance of 10 -8 in any plausible cooling ring. It is concluded that only a small gain is obtained by varying the partition functions, but a very significant gain is made by using higher bending fields. The ring is found to get bigger if the magnet apertures are increased. The ring diameter is found to increase if the momentum spread of the beam is reduced. It is shown that the power can be reduced by allowing a high beamstrahlung energy loss resulting in higher current in the cooling ring. Parameters are also given for a 10 -7 m radian emittance case

  13. 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.

  14. Stable carbon isotopic composition of tree rings from a pine tree from Augustów Wilderness, Poland, as a temperature and local environment conditions indicator.

    Science.gov (United States)

    Pawelczyk, Slawomira; Pazdur, Anna; Halas, Stanislaw

    2004-06-01

    Tree rings can be used as archives of climatic and environmental data with annual resolution. Tree rings widths, maximum late wood density and other parameters as stable composition in tree rings can be used for the reconstruction of past climatic and environmental changes. Stable carbon isotope ratios in tree rings may provide valuable information on past climatic conditions. 13C/12C ratios of plant organic matter can reflect corresponding 13C/12C ratio of atmospheric CO2 during formation of the rings. Investigations of isotopic carbon composition in tree rings from in the ecologically clean the Augustów Wilderness region in the north-eastern part of Poland (22 degrees 58'E, 53 degrees 51'N) (nowadays a sanctuary) were undertaken. Series of delta13C in alpha-cellulose and in wholewood were acquired. Those measurements constituted a part of more complex investigations of carbon isotope composition in tree rings including the measurements of radiocarbon concentration and tree ring widths. This article presents preliminary results. It is argued that contrary to the tree ring widths and delta13C in wholewood that do not reveal significant correlation with temperature, the variation of delta13C in the latewood alpha-cellulose is correlated with combined July and August temperatures. Copyright 2004 Taylor and Francis Ltd.

  15. Dipole Magnets for the LHeC Ring-Ring Option

    CERN Document Server

    Tommasini, D; Chritin, R

    2012-01-01

    The Ring-Ring option of a Large Hadron electron Collider (LHeC) requires 3080 bending magnets, 5.35-meter-long each providing a magnetic field ranging from 0.0127 T at 10 GeV to 0.0763 T at 60 GeV. Main issues in the design of these magnets are the very low injection field, constituting a challenge in achieving a satisfactory field reproducibility from cycle to cycle, and the required compactness to fit in the existing LHC tunnel. This paper describes and discusses a design meeting these requirements, together with its experimental validation by the manufacture and measurement of a 400-mm-long magnet model.

  16. The multi-bend achromat storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Mikael [MAX IV Laboratory Ole Römers v. 1 22100 Lund Sweden (Sweden)

    2016-07-27

    Not very long ago, the 3{sup rd} generation storage ring technology was judged as mature. Most of the 3{sup rd} generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

  17. The multi-bend achromat storage rings

    International Nuclear Information System (INIS)

    Eriksson, Mikael

    2016-01-01

    Not very long ago, the 3"r"d generation storage ring technology was judged as mature. Most of the 3"r"d generation storage rings used the Double-Bend Achromat (DBA) or Triple-Bend Achromat (TBA) concepts. It was however a well-known fact that increasing the number of magnet cells in the rings is a powerful way of decreasing the electron beam emittance and thus the source brilliance, but at the penalty of increasing the size and cost of the rings. Preserving the Dynamic Aperture (DA) in the rings became also an issue when increasing the number of magnet cells. The Multi-Bend Achromat (MBA) concept, including a miniaturization of the ring elements, has now drastically changed the picture. The MBA rings, now in construction or being planned, offer orders of magnitudes higher brilliance than rings of conventional designs. Several light sources around the world are now implementing or planning to implement this MBA concept. This article touches on the science drivers for higher brilliance. We will then describe the MBA concept with its advantages as well as its challenges. A short survey of the MBA activity around the world will also be presented. The author apologies for focusing on the MAX IV project regarding technical solutions. This is motivated by that MAX IV is the facility he knows best and it might be regarded as a fore-runner for the MBA concept.

  18. Ring wormholes via duality rotations

    Directory of Open Access Journals (Sweden)

    Gary W. Gibbons

    2016-09-01

    Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

  19. 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...

  20. Broadband pulsed difference frequency generation laser source centered 3326 nm based on ring fiber lasers

    Science.gov (United States)

    Chen, Guangwei; Li, Wenlei

    2018-03-01

    A broadband pulsed mid-infrared difference frequency generation (DFG) laser source based on MgO-doped congruent LiNbO3 bulk is experimentally demonstrated, which employs a homemade pulsed ytterbium-doped ring fiber laser and a continuous wave erbium-doped ring fiber laser to act as seed sources. The experimental results indicate that the perfect phase match crystal temperature is about 74.5∘C. The maximum spectrum bandwidth of idler is about 60 nm with suitable polarization states of fundamental lights. The central wavelength of idlers varies from 3293 nm to 3333 nm over the crystal temperature ranges of 70.4-76∘C. A jump of central wavelength exists around crystal temperature of 72∘C with variation of about 30 nm. The conversion efficiency of DFG can be tuned with the crystal temperature and polarization states of fundamental lights.

  1. Operation of a five-pole superconducting wiggler in the DCI positron ring and design of the beamline

    International Nuclear Information System (INIS)

    Bazin, C.; Dubuisson, J.M.; Labeque, A.; Level, M.P.; Raoux, D.; Sommer, M.; Zyngier, H.; Chomillier, J.; Frouin, J.; Garreau, Y.; Loupias, G.; Tarbes, J.

    1989-01-01

    A five-pole superconducting wiggler has been installed in the DCI positron ring and operated without disturbing the machine characteristics at full energy (1.85 GeV) and maximum current (300 mA). Three beamlines have been built which feed six beam ports. The first two-crystal monochromator to be used for Compton scattering has been commissioned although the sagittal focusing has not yet been tested

  2. Multiplication modules over non-commutative rings

    International Nuclear Information System (INIS)

    Tuganbaev, A A

    2003-01-01

    It is proved that each submodule of a multiplication module over a regular ring is a multiplicative module. If A is a ring with commutative multiplication of right ideals, then each projective right ideal is a multiplicative module, and a finitely generated A-module M is a multiplicative module if and only if all its localizations with respect to maximal right ideals of A are cyclic modules over the corresponding localizations of A. In addition, several known results on multiplication modules over commutative rings are extended to modules over not necessarily commutative rings

  3. Status of the SLC damping rings

    International Nuclear Information System (INIS)

    Hutton, A.M.; Davies-White, W.A.; Delahaye, J.P.

    1985-06-01

    Electron beams of full design energy 1.21 GeV and nearly full design intensity 4 x 10 10 particles/pulse (design 5 x 10 10 ) have been extracted from the Stanford Linac and successfully stored in the electron damping ring. Beams of less intensity have been extracted from the ring and reinjected into the Linac. The present intensity limits are not thought to be fundamental. The operating experience with the electron ring and the status of the construction of the positron ring will be discussed. 11 refs., 1 fig., 2 tabs

  4. Characterization of heterocyclic rings through quantum chemical topology.

    Science.gov (United States)

    Griffiths, Mark Z; Popelier, Paul L A

    2013-07-22

    Five-membered rings are found in a myriad of molecules important in a wide range of areas such as catalysis, nutrition, and drug and agrochemical design. Systematic insight into their largely unexplored chemical space benefits from first principle calculations presented here. This study comprehensively investigates a grand total of 764 different rings, all geometry optimized at the B3LYP/6-311+G(2d,p) level, from the perspective of Quantum Chemical Topology (QCT). For the first time, a 3D space of local topological properties was introduced, in order to characterize rings compactly. This space is called RCP space, after the so-called ring critical point. This space is analogous to BCP space, named after the bond critical point, which compactly and successfully characterizes a chemical bond. The relative positions of the rings in RCP space are determined by the nature of the ring scaffold, such as the heteroatoms within the ring or the number of π-bonds. The summed atomic QCT charges of the five ring atoms revealed five features (number and type of heteroatom, number of π-bonds, substituent and substitution site) that dictate a ring's net charge. Each feature independently contributes toward a ring's net charge. Each substituent has its own distinct and systematic effect on the ring's net charge, irrespective of the ring scaffold. Therefore, this work proves the possibility of designing a ring with specific properties by fine-tuning it through manipulation of these five features.

  5. Non-Covalent Supported of l-Proline on Graphene Oxide/Fe3O4 Nanocomposite: A Novel, Highly Efficient and Superparamagnetically Separable Catalyst for the Synthesis of Bis-Pyrazole Derivatives

    Directory of Open Access Journals (Sweden)

    Mosadegh Keshavarz

    2018-02-01

    Full Text Available A superparamagnetic graphene oxide/Fe3O4/l-proline nano hybrid that was obtained from the non-covalent immobilization of l-proline on graphene oxide/Fe3O4 nanocomposite was used as a new magnetically separable catalyst for the efficient synthesis of 4,4′-(arylmethylenebis(1H-pyrazol-5-ol derivatives. The prepared heterogeneous catalyst was characterized using FTIR, TGA, DTG, XRD, TEM, SEM, and elemental analysis techniques. Short reaction times (5–15 min, excellent yields (87–98%, and simple experimental procedure with an easy work-up are some of the advantages of the introduced catalyst.

  6. Single photon emission and quantum ring-cavity coupling in InAs/GaAs quantum rings

    International Nuclear Information System (INIS)

    Gallardo, E; Nowak, A K; Sanvitto, D; Meulen, H P van der; Calleja, J M; MartInez, L J; Prieto, I; Alija, A R; Granados, D; Taboada, A G; GarcIa, J M; Postigo, P A; Sarkar, D

    2010-01-01

    Different InAs/GaAs quantum rings embedded in a photonic crystal microcavity are studied by quantum correlation measurements. Single photon emission, with g (2) (0) values around 0.3, is demonstrated for a quantum ring not coupled to the microcavity. Characteristic rise-times are found to be longer for excitons than for biexcitons, resulting in the time asymmetry of the exciton-biexciton cross-correlation. No antibunching is observed in another quantum ring weakly coupled to the microcavity.

  7. Synthesis and antimicrobial studies of novel derivatives of 4-(4-formyl-3-phenyl-1H-pyrazol-1-yl)benzoic acid as potent anti-Acinetobacter baumanni agents

    Science.gov (United States)

    Allison, Devin; Delancey, Evan; Ramey, Hunter; Williams, Conrad; Alsharif, Zakeyah Ali; Al-khattabi, Hessa; Ontko, Allyn; Gilmore, David

    2017-01-01

    Microbial resistance to antibiotics is a global concern. The World Health Organization (WHO) has identified antimicrobial resistance as one the three greatest threats for human beings in the 21st century. Without urgent and coordinated action, the world is moving toward a post-antibiotic era, in which normal infections or minor injuries may become fatal. In an effort to find new agents, we report the synthesis and antimicrobial activities of 40 novel 1,3-diphenyl pyrazole derivatives. These compounds have shown zones of growth inhibition up to 85 mm against Acinetobacter baumannii. We tested the active compounds against this Gram-negative bacterium in minimum inhibitory concentration (MIC) tests and found activity with concentration as low as 4 μg/mL. PMID:28065568

  8. Powder metallurgy ferrous synchronizer ring with brass-based friction layer; Tetsu-do niso shoketsu synchronize ring no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, H; Yoshikawa, K; Miyajima, K; Sugiyama, M [Toyota Motor Corp., Aichi (Japan); Nakamura, M; Ito, M [Japan Powder Metallurgy Co. Ltd., Tokyo (Japan)

    1997-10-01

    Synchronizer rings for manual transmissions are generally made of brass or molybdenum coated brass. Powder metallurgy (PM) synchronizer ring was developed for the purpose of high performance and cost reduction. This synchronizer ring consists of the high strength PM ferrous ring that needs neither special densification nor heat treatment, and it has the brass-based friction layer. New joining technique was required because of that shape and two different materials. Powder of copper-phosphorus alloy are admixed with the friction material. While sintering, that melt and migrate to the interface. Then the friction layer and the ferrous ring are joined tightly. 7 refs., 9 figs., 6 tabs.

  9. Vortex Ring Dynamics in Radially Confined Domains

    Science.gov (United States)

    Stewart, Kelley; Niebel, Casandra; Jung, Sunghwan; Vlachos, Pavlos

    2010-11-01

    Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This study addresses this limitation and studies vortex formation in radially confined domains to analyze the affect of vortex-ring wall interaction on the formation and propagation of the vortex ring. Vortex rings were produced using a pneumatically driven piston cylinder arrangement and were ejected into a long cylindrical tube which defined the confined downstream domain. A range of confinement domains were studied with varying confinement diameters Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) and were processed using an in-house developed cross-correlation PIV algorithm. The experimental analysis was used to facilitate the development of a theoretical model to predict the variations in vortex ring circulation over time within confined domains.

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

    Science.gov (United States)

    Granito, Charles E.; And Others

    1972-01-01

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

  11. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

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

  12. Highly optimized tunable Er3+-doped single longitudinal mode fiber ring laser, experiment and model

    DEFF Research Database (Denmark)

    Poulsen, Christian; Sejka, Milan

    1993-01-01

    A continuous wave (CW) tunable diode-pumped Er3+-doped fiber ring laser, pumped by diode laser at wavelengths around 1480 nm, is discussed. Wavelength tuning range of 42 nm, maximum slope efficiency of 48% and output power of 14.4 mW have been achieved. Single longitudinal mode lasing...... with a linewidth of 6 kHz has been measured. A fast model of erbium-doped fiber laser was developed and used to optimize output parameters of the laser...

  13. Hubble again views Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    Saturn's magnificent ring system is seen tilted edge-on -- for the second time this year -- in this NASA Hubble Space Telescope picture taken on August 10, 1995, when the planet was 895 million miles (1,440 million kilometers) away. Hubble snapped the image as Earth sped back across Saturn's ring plane to the sunlit side of the rings. Last May 22, Earth dipped below the ring plane, giving observers a brief look at the backlit side of the rings. Ring-plane crossing events occur approximately every 15 years. Earthbound observers won't have as good a view until the year 2038. Several of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are from left to right, Enceladus, Tethys, Dione and Mimas. 'The Hubble data shows numerous faint satellites close to the bright rings, but it will take a couple of months to precisely identify them,' according to Steve Larson (University of Arizona). During the May ring plane crossing, Hubble detected two, and possibly four, new moons orbiting Saturn. These new observations also provide a better view of the faint E ring, 'to help determine the size of particles and whether they will pose a collision hazard to the Cassini spacecraft,' said Larson. The picture was taken with Hubble's Wide Field Planetary Camera 2 in wide field mode. This image is a composite view, where a long exposure of the faint rings has been combined with a shorter exposure of Saturn's disk to bring out more detail. When viewed edge-on, the rings are so dim they almost disappear because they are very thin -- probably less than a mile thick.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 data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  14. Photochemistry in Saturn's Ring-Shadowed Atmosphere: Modulation of Hydrocarbons and Observations of Dust Content

    Science.gov (United States)

    Edgington, S. G.; Atreya, S. K.; Wilson, E. H.; Baines, K. H.; West, R. A.; Bjoraker, G. L.; Fletcher, L. N.; Momary, T.

    2016-12-01

    Cassini has been orbiting Saturn for over twelve years now. During this epoch, the ring shadow has moved from covering much of the northern hemisphere with solar inclination of 24 degrees to covering a large swath south of the equator and it continues to move southward. At Saturn Orbit Insertion in 2004, the projection of the A-ring onto Saturn reached as far as 40N along the central meridian (52N at the terminator). At its maximum extent, the ring shadow can reach as far as 48N/S (58N/S at the terminator). The net effect is that the intensity of both ultraviolet and visible sunlight penetrating through the rings to any particular latitude will vary depending on both Saturn's axis relative to the Sun and the optical thickness of each ring system. In essence, the rings act like semi-transparent venetian blinds.Previous work examined the variation of the solar flux as a function of solar inclination, i.e. for each 7.25-year season at Saturn. Here, we report on the impact of the oscillating ring shadow on the photolysis and production rates of hydrocarbons (acetylene, ethane, propane, and benzene) and phosphine in Saturn's stratosphere and upper troposphere. The impact of these production and loss rates on the abundance of long-lived photochemical products leading to haze formation are explored. We assess their impact on phosphine abundance, a disequilibrium species whose presence in the upper troposphere can be used as a tracer of convective processes in the deeper atmosphere.We will also present our ongoing analysis of Cassini's CIRS, UVIS, and VIMS datasets that provide an estimate of the evolving haze content of the northern hemisphere and we will begin to assess the implications for dynamical mixing. In particular, we will examine how the now famous hexagonal jet stream acts like a barrier to transport, isolating Saturn's north polar region from outside transport of photochemically-generated molecules and haze.The research described in this paper was carried out

  15. Vaginal rings for delivery of HIV microbicides.

    Science.gov (United States)

    Malcolm, R Karl; Fetherston, Susan M; McCoy, Clare F; Boyd, Peter; Major, Ian

    2012-01-01

    Following the successful development of long-acting steroid-releasing vaginal ring devices for the treatment of menopausal symptoms and contraception, there is now considerable interest in applying similar devices to the controlled release of microbicides against HIV. In this review article, the vaginal ring concept is first considered within the wider context of the early advances in controlled-release technology, before describing the various types of ring device available today. The remainder of the article highlights the key developments in HIV microbicide-releasing vaginal rings, with a particular focus on the dapivirine ring that is presently in late-stage clinical testing.

  16. 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.

  17. Inorganic glass ceramic slip rings

    Science.gov (United States)

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

    1972-01-01

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

  18. Translational velocity oscillations of piston generated vortex rings

    Science.gov (United States)

    Kumar, Manoj; Arakeri, J. H.; Shankar, P. N.

    1995-11-01

    Experimental results are presented that show that the translational velocities of piston generated vortex rings often undergo oscillations, similar to those recently discovered for drop generated rings. An attempt has been made to minimize uncertainties by utilizing both dye and hydrogen bubbles for visualization and carefully repeating measurements on the same ring and on different realizations under the same nominal piston conditions. The results unambiguously show that under most conditions, both for laminar and turbulent rings and for rings generated from pipes and orifices, the oscillations are present. The present results, together with the earlier results on drop generated rings, give support to the view that translational velocity oscillations are probably an inherent feature of translating vortex ring fields.

  19. Seco-B-Ring Steroidal Dienynes with Aromatic D Ring: Design, Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Marcin Szybinski

    2017-10-01

    Full Text Available Continuing our structure-activity studies on the vitamin D analogs with the altered intercyclic seco-B-ring fragment, we designed compounds possessing dienyne system conjugated with the benzene D ring. Analysis of the literature data and the docking experiments seemed to indicate that the target compounds could mimic the ligands with a good affinity to the vitamin D receptor (VDR. Multi-step synthesis of the C/D-ring building block of the tetralone structure was achieved and its enol triflate was coupled with the known A-ring fragments, possessing conjugated enyne moiety, using Sonogashira protocol. The structures of the final products were confirmed by NMR, UV and mass spectroscopy. Their binding affinities for the full-length human VDR were determined and it was established that compound substituted at C-2 with exomethylene group showed significant binding to the receptor. This analog was also able to induce monocytic differentiation of HL-60 cells.

  20. Saturn's Ring: Pre-Cassini Status and Mission Goals

    Science.gov (United States)

    Cuzzi, Jeff N.; DeVincenzi, Donald L. (Technical Monitor)

    1999-01-01

    In November 1980, and again in August 1981, identical Voyager spacecraft flew through the Saturn system, changing forever the way we think about planetary rings. Although Saturn's rings had been the only known ring system for three centuries, a ring system around Uranus had been discovered by stellar occultations from Earth in 1977, and the nearly transparent ring of Jupiter was imaged by Voyager in 1979 (the presence of material there had been inferred from charged particle experiments on Pioneer 10 and 11 several years earlier). While Saturn had thus temporarily lost its uniqueness as having the only ring system, with Voyager it handily recaptured the role of having the most fascinating one. The Voyager breakthroughs included spiral density and bending waves such as cause galactic structure; ubiquitous fine-scale radial 'irregular' structure, with the appearance of record-grooves; regional and local variations in particle color; complex, azimuthally variable ring structure; empty gaps in the rings, some containing very regular, sharp-edged, elliptical rings and one containing both a small moonlet and incomplete arcs of dusty material; and shadowy 'spokes' that flicker across the main rings. One of the paradigm shifts of this period was the realization that many aspects of planetary rings, and even the ring systems themselves, could be 'recent' on geological timescales. These early results are reviewed and summarized in the Arizona Space Science series volumes 'Saturn'. (An excellent review of ring dynamics at a formative stage is by Goldreich and Tremaine.) From the mid 1980's to the time of this writing, progress has been steady, while at a less heady pace, and some of the novel ring properties revealed by Voyager 1 and 2 are beginning to be better understood. It is clearly impossible to cite, much less review, every advance over the last decade; however, below we summarize the main advances in understanding of Saturn's rings since the mid 1980's, in the context

  1. Photoluminescence studies of individual and few GaSb/GaAs quantum rings

    Directory of Open Access Journals (Sweden)

    M. P. Young

    2014-11-01

    Full Text Available We present optical studies of individual and few GaSb quantum rings embedded in a GaAs matrix. Contrary to expectation for type-II confinement, we measure rich spectra containing sharp lines. These lines originate from excitonic recombination and are observed to have resolution-limited full-width at half maximum of 200 μeV. The detail provided by these measurements allows the characteristic type-II blueshift, observed with increasing excitation power, to be studied at the level of individual nanostructures. These findings are in agreement with hole-charging being the origin of the observed blueshift.

  2. Rings Related to Special Atoms | France-Jackson | Quaestiones ...

    African Journals Online (AJOL)

    Abstract unavailable at this time... Mathematics Subject Classification (1991): 16A21, 16A12 Keywords: ring, special atoms, atoms, *k-ring, prime ring, *-ring, Jacobson, artinia, essential extension, homomorphic image, ideals. Quaestiones Mathematicae 24(1) 2001, 105–109 ...

  3. 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.

  4. Synthesis, Characterization and Antimicrobial Evaluation of Substituted 1,2,4-Triazole Thiones Containing Pyrazole Moiety

    Directory of Open Access Journals (Sweden)

    ALURU GURU PRASAD

    2014-03-01

    Full Text Available Aim: To synthesize a series of novel compounds namely, 4-(3-((substituted-1H-pyrazol-3-yl-methylsulphonyl-5-((3,5,6-trichloro-pyridin-2-yl-oxymethyl-[1,2,4]triazol%u20134%u2013yl-methyl-morpholine (8a-g and evaluate their antimicrobial activity. Material and Method: The chemical structures of newly synthesized compounds were elucidated by IR, 1H NMR, mass spectral and elemental analysis data. Their antimicrobial activities against Staphylococus aureus NCCS 2079, Bacillus Cereus, NCCS 2106, Escherichia coli NCCS 2065, Pseudomanas aeruginos NCCS 2200, Aspergillus niger NCCS 1196 and Candida albicans NCCS 2106 were investigated by employing disk diffusion method and minimum inhibitory concentration was found out by broth dilution method. Results: Elemental analysis of the compounds indicated that the values found by the experiments were very close to theoretically calculated values. IR and 1H NMR spectral assignments of critical functional groups were indicated in each case. Mass spectral fragmentation confirmed the formation of the final product to be screened for antimicrobial activity. Antibacterial and antifungal activity of each of the compounds were evaluated and presented. Each member of the series of compounds was found to be active against tested microbes in particular, the derivative %u20188C%u2019 was found exhibit better antimicrobial activity. Discussion: The compounds demonstrated significant antifungal activity once again evidencing the basic trait of 1,2,4-triazoles.

  5. 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].

  6. Ring Avulsion Injuries: A Systematic Review.

    Science.gov (United States)

    Bamba, Ravinder; Malhotra, Gautam; Bueno, Reuben A; Thayer, Wesley P; Shack, R Bruce

    2018-01-01

    Ring avulsion injuries can range from soft tissue injury to complete amputation. Grading systems have been developed to guide treatment, but there is controversy with high-grade injuries. Traditionally, advanced ring injuries have been treated with completion amputation, but there is evidence that severe ring injuries can be salvaged. The purpose of this systematic review was to pool the current published data on ring injuries. A systematic review of the English literature published from 1980 to 2015 in PubMed and MEDLINE databases was conducted to identify patients who underwent treatment for ring avulsion injuries. Twenty studies of ring avulsion injuries met the inclusion criteria. There were a total of 572 patients reported with ring avulsion injuries. The Urbaniak class breakdown was class I (54 patients), class II (204 patients), and class III (314 patients). The average total arc of motion (TAM) for patients with a class I injury was 201.25 (n = 40). The average 2-point discrimination was 5.6 (n = 10). The average TAM for patients with a class II injury undergoing microsurgical revascularization was 187.0 (n = 114), and the average 2-point discrimination was 8.3 (n = 40). The average TAM for patients with a class III injury undergoing microsurgical revascularization was 168.2 (n = 170), and the average 2-point discrimination was 10.5 (n = 97). Ring avulsion injuries are commonly classified with the Urbaniak class system. Outcomes are superior for class I and II injuries, and there are select class III injuries that can be treated with replantation. Shared decision making with patients is imperative to determine whether replantation is appropriate.

  7. 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....

  8. Novel Fiber-Optic Ring Acoustic Emission Sensor.

    Science.gov (United States)

    Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

    2018-01-13

    Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

  9. Selective extraction of americium(III) over europium(III) ions with pyridylpyrazole ligands. Structure-property relationships

    Energy Technology Data Exchange (ETDEWEB)

    Su, Dongping; Liu, Ying; Li, Shimeng; Ding, Songdong; Jin, Yongdong; Wang, Zhipeng; Hu, Xiaoyang; Zhang, Lirong [Department of chemistry, Sichuan University, Chengdu (China)

    2017-01-18

    To clarify the structure-property relationships of pyridylpyrazole ligands and provide guidance for the design of new and more efficient ligands for the selective extraction of actinides over lanthanides, a series of alkyl-substituted pyridylpyrazole ligands with different branched chains at different positions of the pyrazole ring were synthesized. Extraction experiments showed that the pyridylpyrazole ligands exhibited good selective extraction abilities for Am{sup III} ions, and the steric effects of the branched chain had a significant impact on the distribution ratios of Am{sup III} and Eu{sup III} ions as well as the separation factor. Moreover, both slope analyses and UV/Vis spectrometry titrations indicated the formation of a 1:1 complex of 2-(1-octyl-1H-pyrazol-3-yl)pyridine (C8-PypzH) with Eu{sup III} ions. The stability constant (log K) for this complex obtained from the UV/Vis titration was 4.45 ± 0.04. Single crystals of the complexes of 3-(2-pyridyl)pyrazole (PypzH) with Eu(NO{sub 3}){sub 3} and Sm(NO{sub 3}){sub 3} were obtained; PypzH acts as a bidentate ligand in the crystal structures, and the N atom with a bound H atom did not participate in the coordination. In general, this study revealed some interesting findings on the effects of the alkyl-chain structure and the special complexation between pyridylpyrazole ligands and Ln{sup III} ions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Nilradicals of skew Hurwitz series of rings

    Directory of Open Access Journals (Sweden)

    Morteza Ahmadi

    2015-05-01

    Full Text Available ‎For a ring endomorphism α of a ring R, ‎Krempa called α a rigid endomorphism if aα(a=0 implies a = 0 for a in R. ‎A ring R is called rigid if there exists a rigid endomorphism of R. ‎In this paper‎, ‎we extend the α-rigid property of a ring R to the upper nilradical N_r(R of R. ‎For an endomorphism α and the upper nilradical N_r(R of a ring R, ‎we introduce the condition (*: ‎N_r(R is a α-ideal of R and aα(a in N_r(R implies a in N_r(R for a in R. ‎We study characterizations of a ring R with an endomorphism α satisfying the condition (*, ‎and we investigate their related properties‎. ‎The connections between the upper nilradical of R and the upper nilradical of the skew Hurwitz series ring (HR,α of R are also investigated‎.

  11. Spin transitions in semiconductor quantum rings

    International Nuclear Information System (INIS)

    Baxevanis, Benjamin; Pfannkuche, Daniela

    2010-01-01

    We adopt the path integral Monte Carlo method to accurately resolve the total spin of the ground state of electrons confined in a quantum ring with different geometries. Using this method, an evaluation of the ground state of three electrons in a ring shows a spin transition to the fully polarized state by increasing the radius and thereby enhancing the Coulomb interaction. The total spin of the ground state is determined by the mutual interplay of confinement and electron-electron interaction. An analysis of the four-electron ring demonstrates that in this case no spin transitions take place. Furthermore, the effect of geometric distortion of the ring on its ground state has been investigated. Elliptically deforming the ring breaks the symmetry of the system and leads to the removal of orbital degeneracy. For strong distortion the splitting between hybridized states is sufficient to overcome the exchange-energy saving associated with a higher spin state. We have found that this effect removes the polarization of three electrons. Even in a four-electron ring the ground state is forced by the distortion to be unpolarized and thus suppressing the Hund's rule ground state.

  12. INJECTION EFFICIENCY IN COMPTON RING NESTOR

    Directory of Open Access Journals (Sweden)

    P. I. Gladkikh

    2017-12-01

    Full Text Available NESTOR is the hard X-ray source that is under commissioning at NSC KIPT. NESTOR based on the Compton scattering of laser photons on relativistic electrons. The structure of the facility can be represented as the following components: a linear accelerator, a transport channel, a storage ring, and a laser-optical system. Electrons are stored in the storage ring for energy of 40-200 MeV. Inevitable alignment errors of magnetic elements are strongly effect on the beam dynamics in the storage ring. These errors lead to a shift of the equilibrium orbit relative to the ideal one. Significant shift of the equilibrium orbit could lead to loss of the beam on physical apertures. Transverse sizes of electron and laser beams are only few tens of microns at the interaction point. The shift of electron beam at the interaction point could greatly complicate the operation adjustment of storage ring without sufficient beam position diagnostic system. This article presents the simulation results of the efficiency of electron beam accumulation in the NESTOR storage ring. Also, this article is devoted to electron beam dynamics due to alignment errors of magnetic element in the ring.

  13. Control of ring lasers by means of coupled cavities

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  14. 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

  15. Artificial light harvesting by dimerized Möbius ring

    Science.gov (United States)

    Xu, Lei; Gong, Z. R.; Tao, Ming-Jie; Ai, Qing

    2018-04-01

    We theoretically study artificial light harvesting by a Möbius ring. When the donors in the ring are dimerized, the energies of the donor ring are split into two subbands. Because of the nontrivial Möbius boundary condition, both the photon and acceptor are coupled to all collective-excitation modes in the donor ring. Therefore, the quantum dynamics in the light harvesting is subtly influenced by dimerization in the Möbius ring. It is discovered that energy transfer is more efficient in a dimerized ring than that in an equally spaced ring. This discovery is also confirmed by a calculation with the perturbation theory, which is equivalent to the Wigner-Weisskopf approximation. Our findings may be beneficial to the optimal design of artificial light harvesting.

  16. ring system

    African Journals Online (AJOL)

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

  17. Ring cavity for a Raman capillary waveguide amplifier

    Science.gov (United States)

    Kurnit, N.A.

    1981-01-27

    A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

  18. Ring cavity for a Raman capillary waveguide amplifir

    Science.gov (United States)

    Kurnit, N.A.

    1981-01-27

    A regenerative ring amplifier and regenerative ring oscillator are described which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO/sub 2/ laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplified Stokes signal is synchronous with the mode-locked spikes of the incoming CO/sub 2/ laser pump signal.

  19. 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.

  20. [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.