Phenyl N-(2-methylphenylcarbamate

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Durre Shahwar

2009-07-01

Full Text Available In the title compound, C14H13NO2, the aromatic rings attached to the O and N atoms make dihedral angles of 62.65 (9 and 38.28 (11°, respectively, with the central carbamate group. The benzene rings are oriented at a dihedral angle of 39.22 (10°. In the crystal, a very weak C—H...π interaction occurs.

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...

3-Ethyl-5-(4-methoxyphenoxy-2-(pyridin-4-yl-3H-imidazo[4,5-b]pyridine

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S. Ranjith

2011-07-01

Full Text Available In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5°]. The pyridine ring makes a dihedral angle of 35.5 (5° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking interaction between the phenyl rings of neighbouring molecules [centroid–centroid distance = 3.772 (2 Å, interplanar distance = 3.546 (2 Å and slippage = 1.286 (2 Å].

2-(Diphenylmethylidene-2,3-dihydro-1H-inden-1-one

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Helen Sheridan

2013-08-01

Full Text Available In the title molecule, C22H16O, the indanone ring system is approximately planar with a dihedral angle between the fused rings of 5.13 (14°. Two benzene rings are linked together at one side of a double bond, sitting on either side of the indanone ring system and making dihedral angles of 70.30 (12 and 44.74 (13° with it. In the crystal, hydrogen bonding is not present, but weak C—H...π or π–π interactions occur and molecules form a sheet-like structure in the bc plane.

4-Chloro-N-o-tolylbenzamide

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Hiroyuki Ishida

2008-10-01

Full Text Available In the molecule of the title compound, C14H12ClNO, the two benzene rings are close to coplanar [dihedral angle = 7.85 (4°]. The amide N—C=O plane makes dihedral angles of 34.04 (4 and 39.90 (3°, respectively, with the 4-chloro- and 2-methylphenyl rings. In the crystal structure, intermolecular N—H...O hydrogen bonds link the molecules into chains.

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

Science.gov (United States)

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].

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.

Integral pentavalent Cayley graphs on abelian or dihedral groups

Indian Academy of Sciences (India)

MOHSEN GHASEMI

ghasemi@urmia.ac.ir. MS received 8 July 2015; revised 10 July 2016. Abstract. A graph is called integral, if all of its eigenvalues are integers. In this paper, we give some results about integral pentavalent Cayley graphs on abelian or dihedral.

3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

Science.gov (United States)

Ranjith, S.; SubbiahPandi, A.; Suresh, A. D.; Pitchumani, K.

2011-01-01

In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]. PMID:21837144

1-O-Acetyl-3,4,6-tri-O-benzyl-2-C-bromomethyl-2-deoxy-α-d-glucopyranose

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Henok H. Kinfe

2013-01-01

Full Text Available In the title compound, C30H33BrO6, the pyranose ring adopts a chair conformation. Two of the O-benzyl phenyl rings lie almost perpendicular to C/C/C/O plane formed by the ring atoms not attached to these O-benzyl phenyl rings, and form dihedral angles of 85.1 (2 and 64.6 (2°, while the third O-benzyl phenyl ring is twisted so that it makes a dihedral angle 34.9 (2° to this C/C/C/O plane. This twist is ascribed to the formation of an S(8 loop stabilized by a weak intramolecular C—H...O hydrogen bond.

A fast and accurate dihedral interpolation loop subdivision scheme

Science.gov (United States)

Shi, Zhuo; An, Yalei; Wang, Zhongshuai; Yu, Ke; Zhong, Si; Lan, Rushi; Luo, Xiaonan

2018-04-01

In this paper, we propose a fast and accurate dihedral interpolation Loop subdivision scheme for subdivision surfaces based on triangular meshes. In order to solve the problem of surface shrinkage, we keep the limit condition unchanged, which is important. Extraordinary vertices are handled using modified Butterfly rules. Subdivision schemes are computationally costly as the number of faces grows exponentially at higher levels of subdivision. To address this problem, our approach is to use local surface information to adaptively refine the model. This is achieved simply by changing the threshold value of the dihedral angle parameter, i.e., the angle between the normals of a triangular face and its adjacent faces. We then demonstrate the effectiveness of the proposed method for various 3D graphic triangular meshes, and extensive experimental results show that it can match or exceed the expected results at lower computational cost.

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].

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

5,6-Dipropylphthalazino[2,3-a]cinnoline-8,13-dione

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G. Vimala

2016-04-01

Full Text Available In the title compound, C22H22N2O2, the two central fused pyridazine rings have screw-boat conformations and the dihedral angle between their mean planes is 36.22 (8°. The mean plane of the cinnoline ring system makes a dihedral angle of 46.56 (5° with the mean plane of the phthalazine ring to which it is fused. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming chains along the b axis. The chains are reinforced by C—H...π interactions.

(3′R-3′-Benzyl-2′,3′-dihydro-1H-spiro[indole-3,1′-naphtho[2,3-c]pyrrole]-2,4′,9′-trione

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Garima Sharma

2012-09-01

Full Text Available In the title compound, C26H18N2O3, the maximum deviations from planarity for the tetrahydro-1H-naphtho[2,3-c]pyrrole and indoline rings systems are 0.091 (1 and 0.012 (2 Å, respectively. These ring systems make a dihedral angle of 89.95 (6° with each other and they make dihedral angles of 73.42 (8 and 71.28 (9°, respectively, with the benzene ring. In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generate R22(8 loops and C—H...O interactions connect the dimers into corrugated sheets lying parallel to the bc plane.

6-Chloro-3-[5-(3-methoxy-8-methyl-4-quinolyl-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl]-2-methyl-4-phenylquinoline

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Hoong-Kun Fun

2009-11-01

Full Text Available In the title compound, C36H29ClN4O, the dihydropyrazole ring adopts an envelope conformation. The two quinoline ring systems (r.m.s. deviations = 0.029 and 0.018 Å are oriented at a dihedral angle of 71.43 (4°. One of the quinoline rings makes a dihedral angle of 65.40 (7° with the phenyl substituent. In the crystal, molecules are linked into chains along the b axis by intermolecular C—H...N hydrogen bonds. In addition, C—H...π and π–π [centroid–centroid distance = 3.7325 (8 Å] interactions are observed.

Registration of Images with N-fold Dihedral Blur

Czech Academy of Sciences Publication Activity Database

Pedone, M.; Flusser, Jan; Heikkila, J.

2015-01-01

Roč. 24, č. 3 (2015), s. 1036-1045 ISSN 1057-7149 R&D Projects: GA ČR GA13-29225S; GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Image registration * blurred images * N-fold rotational symmetry * dihedral symmetry * phase correlation Subject RIV: JD - Computer Applications, Robotics Impact factor: 3.735, year: 2015 http://library.utia.cas.cz/separaty/2015/ZOI/flusser-0441247.pdf

(1E,2E-1,2-Bis(2,2-diphenylhydrazin-1-ylideneethane

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Angel Mendoza

2010-09-01

Full Text Available In the crystal structure of the title compound, C26H22N4, the molecule is located on an inversion centre and shows an E configuration with respect to each C=N bond. The dihedral angle between the phenyl rings in the diphenylhydrazone group is 83.69 (11°. These two rings make dihedral angles of 30.53 (15 and 84.53 (16° with the central N—N=C—C=N—N dihydrazonoethane plane. Intermolecular C—H...π interactions are observed.

Dihedral flavor symmetries

Energy Technology Data Exchange (ETDEWEB)

Blum, Alexander Simon

2009-06-10

This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D{sub 4}, the other describing quarks and employing the symmetry D{sub 14}. In the latter model it is the quark mixing matrix element V{sub ud} - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)

Dihedral flavor symmetries

International Nuclear Information System (INIS)

Blum, Alexander Simon

2009-01-01

This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D 4 , the other describing quarks and employing the symmetry D 14 . In the latter model it is the quark mixing matrix element V ud - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)

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.

Ethyl 13-(4-chlorophenyl-11-methyl-6-oxo-5-phenyl-8-thia-3,4,5,10-tetraazatricyclo[7.4.0.02,7]trideca-1(9,2(7,3,10,12-pentaene-12-carboxylate

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Elham A. Al-Taifi

2016-05-01

Full Text Available In the title molecule, C24H17ClN4O3S, the central tricyclic moiety is twisted slightly, as indicated by the dihedral angles of 4.86 (5 and 0.97 (6°, respectively, between the five-membered ring and the C3N3 and pyridyl rings. Additionally, the chlorobenzene ring makes a dihedral angle of 65.80 (5° with the pyridyl ring. Weak C—H...O, C—Cl...N [3.0239 (13 Å] and π–π stacking interactions [inter-centroid distance between thienyl rings = 3.6994 (8 Å, and between thienyl and pyridyl rings = 3.7074 (8 Å] contribute to the molecular packing. The ethyl group in the ester moiety is disordered over two sets of sites, with the major component having an occupancy of 0.567 (11.

Dihedral angle control to improve the charge transport properties of conjugated polymers in organic field effect transistors

Science.gov (United States)

Dharmapurikar, Satej S.; Chithiravel, Sundaresan; Mane, Manoj V.; Deshmukh, Gunvant; Krishnamoorthy, Kothandam

2018-03-01

Diketopyrrolopyrrole (DPP) and i-Indigo (i-Ind) are two monomers that are widely explored as active materials in organic field effect transistor and solar cells. These two molecules showed impressive charge carrier mobility due to better packing that are facilitated by quadrupoles. We hypothesized that the copolymers of these monomers would also exhibit high charge carrier mobility. However, we envisioned that the dihedral angle at the connecting point between the monomers will play a crucial role in packing as well as charge transport. To understand the impact of dihedral angle on charge transport, we synthesized three copolymers, wherein the DPP was sandwiched between benzenes, thiophenes and furans. The copolymer of i-Indigo and furan comprising DPP showed a band gap of 1.4 eV with a very high dihedral angle of 179°. The polymer was found to pack better and the coherence length was found to be 112 Å. The hole carrier mobility of these polymer was found to be highest among the synthesized polymer i.e. 0.01 cm2/vs. The copolymer comprising benzene did not transport hole and electrons. The dihedral angle at the connecting point between i and Indigo and benzene DPP was 143 Å, which the packing and consequently charge transport properties.

2-(4-Bromophenyl-5-fluoro-3-phenylsulfinyl-1-benzofuran

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Hong Dae Choi

2010-08-01

Full Text Available In the title compound, C20H12BrFO2S, the O atom and the phenyl group of the phenylsulfinyl substituent lie on opposite sides of the plane through the benzofuran fragment; the phenyl ring is nearly perpendicular to this plane [dihedral angle = 86.98 (6°]. The 4-bromophenyl ring is rotated slightly out of the benzofuran plane, making a dihedral angle of 1.56 (8°. The crystal structure features aromatic π–π interactions between the furan and phenyl rings of neighbouring molecules [centroid–centroid distance = 3.506 (3 Å], and an intermolecular C—H...π interaction. The crystal structure also exhibits a short intermolecular S...S contact [3.2635 (8 Å].

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°.

Dimethyl 4,4′-dihydroxy-3,3′-{[(3aRS,7aRS-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene}dibenzoate

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Augusto Rivera

2011-11-01

Full Text Available The title compound, C25H30N2O6, has the imidazolidine ring in an envelope conformation. There are two intramolecular O—H...N hydrogen-bond interactions with graph-set motif S(6. The cyclohexane ring adopts a slightly distorted chair conformation. One methyl carboxylate substituent forms a dihedral angle of 12.00 (5° with the plane of the benzene ring, while the other methyl carboxylate group is almost coplanar, making a dihedral angle of 2.26 (9°. In the crystal, pairs of intermolecular C—H...O hydrogen bonds form racemic dimers, corresponding to an R22(18 graph-set motif. Further weak C—H...O interactions generate a chain running along the c axis.

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

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Md. Lutfor Rahman

2016-03-01

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

(E-1-(4-Aminophenyl-3-(naphthalen-2-ylprop-2-en-1-one

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Thawanrat Kobkeatthawin

2011-05-01

Full Text Available The molecule of the title chalcone derivative, C19H15NO, exists in a trans configuration with respect to the C=C double bond. The molecule is slightly twisted with a dihedral angle of 6.12 (12° between the benzene ring and the naphthalene ring system. The prop-2-en-1-one bridge is nearly planar, with an r.m.s. deviation of 0.0194 (2, and makes dihedral angles of 8.05 (19 and 11.47 (18° with the benzene ring and the naphthalene ring system, respectively. In the crystal, molecules are linked by N—H...O hydrogen bonds into chains along the b axis. Weak N—H...π and C—H...π interactions and a short N...O contact [2.974 (4 Å] are also observed.

(Z-3-(Anthracen-9-yl-1-(2-ethoxyphenylprop-2-en-1-oneThis paper is dedicated to the late His Royal Highness Prince Mahidol of Songkla for his contributions to the development of medical education in Thailand on the occasion of Mahidol Day which falls on the 24th September.

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Hoong-Kun Fun

2010-10-01

Full Text Available The molecule of the title chalcone, C25H20O2, consisting of 2-ethoxyphenyl and anthracene rings bridged by a prop-2-en-1-one unit, is twisted and exists in the Z configuration with respect to the central C=C bond. The dihedral angle between the benzene and anthracene rings is 78.17 (9°. The propene unit makes dihedral angles of 44.5 (2 and 81.1 (2° with the benzene and anthracene rings, respectively. The ethoxy substituent is almost coplanar with the attached benzene ring [C—O—C—C torsion angle = 178.57 (19°]. In the crystal, molecules are linked into chains along the a axis by weak C—H...O interactions. The crystal structure is further stabilized by C—H...π interactions.

3′,6′-Bis(diethylamino-3H-spiro[2-benzothiophene-1,9′-xanthene]-3-thione

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Bing-Yuan Su

2008-11-01

Full Text Available The title compound, C28H30N2OS2, was obtained by thionation of 3′,6′-bis(diethylamino-3H-spiro[isobenzofuran-1,9′-xanthene]-3-one with 2,4-bis(p-methoxyphenyl-1,3-dithiadiphosphetane disulfide (Lawesson's reagent. The planes of the two benzene rings of the xanthene system are inclined at a dihedral angle of 17.4 (1°, and the plane of the dithiophthalide group and the planes through the two benzene rings of the xanthene system make dihedral angles of 80.2 (1 and 82.8 (1°, respectively.

2-Isopropyl-5-methylcyclohexyl quinoline-2-carboxylate

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E. Fazal

2014-01-01

Full Text Available In the title compound, C20H25NO2, the cyclohexyl ring adopts a slightly disordered chair conformation. The dihedral angle between the mean planes of the quinoline ring and the carboxylate group is 22.2 (6°. In the crystal, weak C—H...N interactions make chains along [010].

3-Methylpyridinium 4-nitrobenzoate–4-nitrobenzoic acid (1/1

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P. Sivakumar

2016-06-01

Full Text Available In the title compound, C6H8N+·C7H4NO4−·C7H5NO4, the cation is protonated at its pyridine N atom and makes a dihedral angle of 74.14 (12° with the benzene ring of the anion. The benzene ring of the neutral molecule and the pyridine ring are inclined at an angle of 79.20 (12°. The two benzene rings form a dihedral angle of 6.00 (12° with each other. In the crystal, N—H...O, O—H...O and C—H...O hydrogen bonds link the cations, anions and neutral molecules to form layers parallel to the ac plane, which enlose R44(18 ring motifs. The layers are linked by further C—H...O hydrogen bonds and C—H...π interactions, forming a three-dimensional supramolecular architecture.

2,3-Dibromo-3-(2-bromophenyl-1-(3-phenylsydnon-4-ylpropan-1-one

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Balakrishna Kalluraya

2010-12-01

Full Text Available In the title compound [systematic name: 2,3-dibromo-3-(2-bromophenyl-1-(5-oxido-3-phenyl-1,2,3-oxadiazol-3-ium-4-ylpropan-1-one], C17H11Br3N2O3, the oxadiazole ring is essentially planar, with a maximum deviation of 0.003 (1 Å. The –CHBr–CHBr– chain and bromophenyl ring are disordered over two sets of sites with a refined occupany ratio of 0.756 (5:0.244 (5. The central oxadiazole ring makes dihedral angles of 54.07 (11 and 13.76 (18° with the attached phenyl and the major component of the bromo-substituted benzene rings, respectively. The dihedral angle between the major and minor components of the bromophenyl rings is 13.4 (5°. In the crystal structure, molecules are connected by C—H...O hydrogen bonds, forming [010] ribbons.

N-(2-Chlorophenyl-2-methylbenzamide

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B. Thimme Gowda

2008-08-01

Full Text Available In the structure of the title compound (N2CP2MBA, C14H12ClNO, the conformations of the N—H and C=O bonds are trans to each other. Furthermore, the conformation of the N—H bond is syn to the ortho-chloro group in the aniline ring and the C=O bond is syn to the ortho-methyl substituent in the benzoyl ring, similar to what is observed in 2-chloro-N-(2-chlorophenylbenzamide and 2-methyl-N-phenylbenzamide. The amide group makes almost the same dihedral angles of 41.2 (14 and 42.2 (13° with the aniline and benzoyl rings, respectively, while the dihedral angle between the benzoyl and aniline rings is only 7.4 (3°. The molecules in N2CP2MBA are packed into chains through N—H...O hydrogen bonds.

Electric Dipole-Magnetic Dipole Polarizability and Anapole Magnetizability of Hydrogen Peroxide as Functions of the HOOH Dihedral Angle.

Science.gov (United States)

Pelloni, S; Provasi, P F; Pagola, G I; Ferraro, M B; Lazzeretti, P

2017-12-07

The trace of tensors that account for chiroptical response of the H 2 O 2 molecule is a function of the HO-OH dihedral angle. It vanishes at 0° and 180°, due to the presence of molecular symmetry planes, but also for values in the range 90-100° of this angle, in which the molecule is unquestionably chiral. Such an atypical effect is caused by counterbalancing contributions of diagonal tensor components with nearly maximal magnitude but opposite sign, determined by electron flow in open or closed helical paths, and associated with induced electric and magnetic dipole moments and anapole moments. For values of dihedral angle external to the 90-100° interval, the helical paths become smaller in size, thus reducing the amount of cancellation among diagonal components. Shrinking of helical paths determines the appearance of extremum values of tensor traces approximately at 50° and 140° dihedral angles.

9-Butyl-9H-carbazole

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2009-03-01

Full Text Available The title compound, C16H17N, is a carbazole derivative that has been designed and synthesized as a potential organic electronic device, such as an OLED. The tricyclic aromatic ring system is essentially planar, the two outer rings making a dihedral angle of 4.8 (1°. No classical hydrogen bonds are observed in the crystal structure.

Freeman-Durden Decomposition with Oriented Dihedral Scattering

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Yan Jian

2014-10-01

Full Text Available In this paper, when the azimuth direction of polarimetric Synthetic Aperature Radars (SAR differs from the planting direction of crops, the double bounce of the incident electromagnetic waves from the terrain surface to the growing crops is investigated and compared with the normal double bounce. Oriented dihedral scattering model is developed to explain the investigated double bounce and is introduced into the Freeman-Durden decomposition. The decomposition algorithm corresponding to the improved decomposition is then proposed. The airborne polarimetric SAR data for agricultural land covering two flight tracks are chosen to validate the algorithm; the decomposition results show that for agricultural vegetated land, the improved Freeman-Durden decomposition has the advantage of increasing the decomposition coherency among the polarimetric SAR data along the different flight tracks.

1-Acetyl-5-ferrocenyl-3-phenyl-2-pyrazoline

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Orhan Büyükgüngör

2009-02-01

Full Text Available In the title compound, [Fe(C5H5(C16H15N2O], the pyrazoline ring and the phenyl ring are nearly coplanar, making a dihedral angle of 6.54 (2°, while the substituted cyclopentadienyl ring is twisted out of the pyrazoline ring plane by 81.32 (1°. The molecules in the crystal structure are held together by weak C—H...O intermolecular hydrogen bonds and two C—H...π interactions.

1-[2-(4-Bromobenzyloxy-2-phenylethyl]-1H-1,2,4-triazole

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Tuncer Hökelek

2008-10-01

Full Text Available In the molecule of the title compound, C17H16BrN3O, the triazole ring is oriented at dihedral angles of 6.14 (9° and 82.08 (9°, respectively, with respect to the phenyl and bromobenzene rings. The dihedral angle between the bromobenzene and phenyl rings is 87.28 (7°. The intramolecular C—H...O hydrogen bond results in the formation of a planar five-membered ring, which is oriented at a dihedral angle of 0.13 (6° with respect to the bromobenzene ring. There is an intermolecular C—H...π contact between a methylene group and the bromobenzene ring.

3-Fluoro-N-(p-tolylbenzamide

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Aamer Saeed

2008-11-01

Full Text Available In the crystal structure of the title compound, C14H12FNO, the amide –NHCO– mean plane makes dihedral angles of 28.6 (2 and 37.5 (2° with the mean planes through the fluorobenzene and methylbenzene units, respectively. The dihedral angle between the two benzene ring mean planes is 65.69 (10°. In the crystal structure, molecules are linked through N—H...O hydrogen bonds and stack along the b axis.

2-Ethoxy-4-(4-methylphenyl-6-phenylpyridine-3-carbonitrile

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Shaaban K. Mohamed

2012-08-01

Full Text Available The title compound, C21H18N2O, crystallized with two independent molecules (A and B in the asymmetric unit. In molecule A, the central pyridine ring forms dihedral angles of 14.55 (13 and 39.14 (12° with the terminal phenyl and benzene rings, respectively. The latter rings make a dihedral angle of 33.06 (13° with each other. The corresponding values for molecule B are 26.86 (13, 41.82 (12 and 38.99 (13°, respectively. In the crystal, the B molecules are linked via a pair of weak C—H...N hydrogen bonds, forming inversion dimers. In addition, C—H...π interactions and π–π [centroid–centroid distances = 3.5056 (16 and 3.8569 (17 Å] stacking interactions are observed.

N-(1,3-Dioxo-2,3-dihydro-1H-isoindol-2-yl-4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxamide

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Hoong-Kun Fun

2012-09-01

Full Text Available The asymmetric unit of the title compound, C27H16F2N2O4, consists of two crystallographically independent molecules (A and B. In molecule B, the isoindoline-1,3-dione ring system is disordered over two set of sites with a site-occupancy ratio of 0.658 (12:0.342 (12. In molecule A, the fluoro-substituted benzene rings make dihedral angles of 18.36 (8 and 46.37 (8° with the central benzene ring, whereas the corresponding angles are 40.90 (8 and 52.89 (9° in molecule B. The isoindoline ring system in molecule A and the major and minor components of the disordered isoindoline ring system in molecule B make dihedral angles of 58.50 (4, 54.13 (16 and 70.01 (28 °, respectively, with their attached benzene rings, linked through the amide group. An intramolecular O—H...O hydrogen bond generates an S(6 ring in each molecule. In the crystal, molecules are linked by N—H...O, C—H...F and C—H...O hydrogen bonds into sheets lying parallel to the bc plane. The crystal studied was a non-merohedral twin with a refined twin component ratio of 0.9316 (8:0.0684 (8.

(4′-Acetyloxy-1,3,1′-trioxo-1,3,4,4a,4b,5,6,7,9,9a-decahydrospiro[indene-2,9′-pyrano[4,3-a]pyrrolizin]-3′-ylmethyl acetate

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S. Lakshmi

2013-12-01

Full Text Available In the title compound, C23H23NO8, the dihedral angle between the five- and six-membered rings of the indene-dione moiety is 3.09 (13°. The mean plane of the five-membered ring (which has a flat envelope conformation with the spiro C atom as the flap is inclined to the mean plane of the central five-membered ring of the pyrrolizine unit by 76.48 (12°. This central ring has a twist conformation on the N—C(spiro bond. The outer ring of the pyrrolizine unit has an envelope conformation with the N atom as the flap. The mean planes of these two fused rings are inclined to one another by 65.28 (15°. The pyran ring has a screw-boat conformation and its mean plane makes a dihedral angle of 29.50 (11° with the mean plane of the central five-membered ring of the pyrrolizine unit. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane.

Crystal structure of 1-{4-hydroxy-3-[(pyrrolidin-1-ylmethyl]phenyl}-3-phenylprop-2-en-1-one

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Abdullah Aydın

2016-05-01

Full Text Available In the title compound, C20H21NO2, the pyrrolidine ring adopts an envelope conformation with the N atom at the flap position. The central benzene ring makes dihedral angles of 21.39 (10 and 80.10 (15° with the phenyl ring and the mean plane of the pyrrolidine ring, respectively. The molecular conformation is stabilized by an intramolecular O—H...N hydrogen bond, which closes an S(6 ring. A weak C—H...π interaction is observed in the crystal.

(4S)-4-(3,4-Dichloro?phen?yl)-1?-methyl-4?-phenyl-3,4-dihydronaphthalene-2-spiro-3?-pyrrolidine-2?-spiro-1??-acenaphthyl?ene-1,2??(2H,1??H)-dione

OpenAIRE

Murugan, R.; Gunasekaran, B.; Narayanan, S. Sriman; Manivannan, V.

2008-01-01

In the title compound, C37H27Cl2NO2, the 3,4-dichloro?phenyl ring makes a dihedral angle of 46.66?(6)? with the phenyl ring. The mol?ecular structure is stabilized by weak intra?molecular C?H?O inter?actions and the crystal structure is stabilized by weak inter?molecular C?H?O inter?actions. The C?C?C?C?C five-membered ring is planar, while the C?C?C?C?N five-membered ring adopts a half-chair conformation.

Ethyl 2-[4-(benzyloxyanilino]-4-oxo-4,5-dihydrofuran-3-carboxylate

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S. Sriman Narayanan

2008-12-01

Full Text Available In the title compound, C20H19NO5, the dihydrofuran ring is almost planar [maximum deviation of 0.021 (2°] and makes dihedral angles of 28.1 (7 and 54.5 (5° with the benzyl and phenylamino rings, respectively. The molecular packing is stabilized by intramolecular N—H...O hydrogen bonds and intermolecular C—H...O interactions.

trans-Diaquabis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole]cobalt(II bis(tetrafluoridoborate

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Fouad Bentiss

2011-07-01

Full Text Available The bidentate 1,3,4-thiadiazole ligand substituted by two 2-pyridyl rings (denoted L has been found to produce the new monomeric title complex, [Co(C12H8N4S2(H2O2](BF42. The thiadiazole and pyridyl rings surrounding the Co atom are almost coplanar [dihedral angle = 4.35 (7°]. The mean plane defined by these heterocyclic moieties makes a dihedral angle of 18.72 (6° with the non-coordinated pyridyl ring. The Co2+ cation, located at a crystallographic center of symmetry, is bonded to two ligands and two water molecules in a trans configuration in an octahedral environment. The tetrafluoridoborate ions can be regarded as free anions in the crystal lattice. Nevertheless, they are involved in an infinite two-dimensional network along the [010] and [101] directions of O—H...F hydrogen bonds.

4,4′-[Thiophene-2,5-diylbis(ethyne-2,1-diyl]dibenzonitrile

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Kari Rissanen

2008-04-01

Full Text Available In the solid state, the title compound, C22H10N2S, forms centrosymmetric dimers by pairs of non-classical C—H...S hydrogen bonds linking approximately coplanar molecules. The benzene ring involved in this interaction makes a dihedral angle of only 7.21 (16° with the thiophene ring, while the other benzene ring is twisted somewhat out of the plane, with a dihedral angle of 39.58 (9°. The hydrogen-bonded dimers stack on top of each other with an interplanar spacing of 3.44 Å. C—H...N hydrogen bonds link together stacks that run in approximately perpendicular directions. Each molecule thus interacts with 12 adjacent molecules, five of them approaching closer than the sum of the van der Waals radii for the relevant atoms. Optimization of the inter-stack contacts contributes to the non-planarity of the molecule.

5-(2,5-Dioxooxolan-3-yl-8-methyl-3,3a,4,5-tetrahydro-1H-naphtho[1,2-c]furan-1,3-dione

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Y. Z. Guo

2013-02-01

Full Text Available In the title compound, C17H14O6, the dihedral angle between the two anhydride rings is 76.01 (8°while the dihedral angles between the benzene and anhydride rings are 42.60 (7 and 68.94 (7°. The cyclohexene ring of the tetrahydronaphthalene unit exhibits an envelope conformation.

2-(2-Chlorophenyl-2,3-dihydroquinazolin-4(1H-one

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Ming-Jian Li

2009-09-01

Full Text Available The title compound, C14H11ClN2O, was synthesized by the reaction of 2-chlorobenzaldehyde and 2-aminobenzamide in an ionic liquid. The pyrimidine ring adopts a skew-boat conformation and the two benzene rings make a dihedral angle of 87.1 (1°. In the crystal, N—H...O and C—H...N hydrogen bonding links the molecules along b.

1,10,10-Trimethyl-5-phenyl-3-oxa-4-azatricyclo[5.2.1.02,6]dec-4-en-2-ol

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Moha Berraho

2013-08-01

Full Text Available The title compound, C17H21NO2, was synthesized by the reaction of (1R-(+-3-benzylcamphor and hydroxylamine. The oxazole ring makes a dihedral angle of 23.42 (16° with the phenyl ring. The six-membered ring of the norboryl group adopts a boat conformation, whereas each of the five-membered rings of the norboryl group displays a flattened envelope conformation, with the C atom carrying the methyl groups representing the flap for both rings. In the crystal, molecules are linked into zigzag chains propagating along the b axis by O—H...N hydrogen bonds.

Teaching Molecular Symmetry of Dihedral Point Groups by Drawing Useful 2D Projections

Science.gov (United States)

Chen, Lan; Sun, Hongwei; Lai, Chengming

2015-01-01

There are two main difficulties in studying molecular symmetry of dihedral point groups. One is locating the C[subscript 2] axes perpendicular to the C[subscript n] axis, while the other is finding the s[subscript]d planes which pass through the C[subscript n] axis and bisect the angles formed by adjacent C[subscript 2] axes. In this paper, a…

Crystal structures of 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide and bis(2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-(dicyanomethylenepropane-1,3-diide

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Zouaoui Setifi

2015-05-01

Full Text Available In 2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide, C10H9N2+·C9H5N4O−, (I, the ethyl group in the anion is disordered over two sets of atomic sites with occupancies 0.634 (9 and 0.366 (9, and the dihedral angle between the ring planes in the cation is 2.11 (7°. The two independent C(CN2 groups in the anion make dihedral angles of 10.60 (6 and 12.44 (4° with the central propenide unit, and the bond distances in the anion provide evidence for extensive electronic delocalization. In bis(2,2′-bipyridin-1-ium 1,1,3,3-tetracyano-2-(dicyanomethylenepropane-1,3-diide [alternative name bis(2,2′-bipyridin-1-ium tris(dicyanomethylenemethanediide], 2C10H9N2+·C10N62− (II, the dihedral angles between the ring planes in the two independent cations are 7.7 (2 and 10.92 (17°. The anion exhibits approximate C3 symmetry, consistent with extensive electronic delocalization, and the three independent C(CN2 groups make dihedral angles of 23.8 (2, 27.0 (3 and 27.4 (2° with the central plane. The ions in (I are linked by an N—H...N hydrogen bond and the resulting ion pairs are linked by two independent C—H...N hydrogen bonds, forming a ribbon containing alternating R44(18 and R44(26 rings, where both ring types are centrosymmetric. The ions in (II are linked by two independent N—H...N hydrogen bonds and the resulting ion triplets are linked by a C—H...N hydrogen bond, forming a C21(7 chain containing anions and only one type of cation, with the other cation linked to the chain by a further C—H...N hydrogen bond.

10-Ethyl-3-(5-methyl-1,3,4-oxadiazol-2-yl-10H-phenothiazine

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Li-Cheng Sun

2012-03-01

Full Text Available In the title compound, C17H15N3OS, the phenothiazine ring system is slightly bent, with a dihedral angle of 13.68 (7° between the benzene rings. The dihedral angle between the oxadiazole ring and the adjacent benzene ring is 7.72 (7°. In the crystal, a π–π interaction with a centroid–centroid distance of 3.752 (2 Å is observed between the benzene rings of neighbouring molecules.

4-Hydroxy-3-methoxybenzaldehyde–nicotinamide (1/1

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Fiona N.-F. How

2011-12-01

Full Text Available In the title compound, C6H6N2O·C8H8O3, an equimolar co-crystal of nicotinamide and vanillin, the aromatic ring and the amide fragment of the nicotinamide molecule make a dihedral angle of 32.6 (2°. The vanillin molecule is almost planar, with an r.m.s. deviation for all non-H atoms of 0.0094 Å. The vaniline and nicotinamide aromatic rings are nearly coplanar, the dihedral angle between them being 3.20 (9°. In the crystal, the two components are linked through N—H...O and O—H...N hydrogen bonds into chains along the a axis. The chains are connected via C—H...O interactions, forming a three-dimensional polymeric structure.

2-Benzylsulfanyl-N-(1,3-dimethylimidazolidin-2-ylideneaniline

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Ulrich Flörke

2013-04-01

Full Text Available The molecular structure of the title compound, C18H21N3S, shows a twisted conformation with a dihedral angle of 67.45 (4° between the aromatic ring planes and an N—C—C—S torsion angle of −5.01 (13°. The imidazolidine ring and the aniline moiety make a dihedral angle of 56.03 (4° and the asscociated C—N—C angle is 125.71 (10°. The guanidine-like C=N double bond is clearly localized, with a bond length of 1.2879 (14 Å. The C—S—C angle is 102.12 (5° and the S—C(aromatic and S—C bond lengths are 1.7643 (11 and 1.8159 (12 Å.

Ethyl 2-amino-4-(3-chlorophenyl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxylate

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Xiao Hu

2009-06-01

Full Text Available The title molecule, C22H16ClNO5, was obtained by the reaction of (E-ethyl 3-(3-chlorophenyl-2-cyanoacrylate and 2-hydroxynaphthalene-1,4-dione catalysed by triethylamine in ethanol. In the crystal structure, the chlorobenzene ring makes a dihedral angle of 88.63 (4° with the fused ring system. The six-membered ring formed by an intramolecular N—H...O hydrogen bond is almost planar. The crystal packing is stabilized by N—H...O hydrogen bonds.

Crystal structure of 3-({[(morpholin-4-yl)carbono-thio-yl]sulfan-yl}acet-yl)phenyl benzoate.

Science.gov (United States)

Ambekar, Sachin P; Mahesh Kumar, K; Shirahatti, Arun Kumar M; Kotresh, O; Anil Kumar, G N

2014-11-01

In the title compound, C20H19NO4S2, the morpholine ring adopts the expected chair conformation. The central phenyl ring makes dihedral angles of 67.97 (4) and 7.74 (3)°, respectively, with the benzoate phenyl ring and the morpholine mean plane. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming zigzag chains along the b-axis direction. C-H⋯π inter-actions link centrosymmetrically related mol-ecules, reinforcing the three-dimensional structure.

Predicting beta-turns and their types using predicted backbone dihedral angles and secondary structures.

Science.gov (United States)

Kountouris, Petros; Hirst, Jonathan D

2010-07-31

Beta-turns are secondary structure elements usually classified as coil. Their prediction is important, because of their role in protein folding and their frequent occurrence in protein chains. We have developed a novel method that predicts beta-turns and their types using information from multiple sequence alignments, predicted secondary structures and, for the first time, predicted dihedral angles. Our method uses support vector machines, a supervised classification technique, and is trained and tested on three established datasets of 426, 547 and 823 protein chains. We achieve a Matthews correlation coefficient of up to 0.49, when predicting the location of beta-turns, the highest reported value to date. Moreover, the additional dihedral information improves the prediction of beta-turn types I, II, IV, VIII and "non-specific", achieving correlation coefficients up to 0.39, 0.33, 0.27, 0.14 and 0.38, respectively. Our results are more accurate than other methods. We have created an accurate predictor of beta-turns and their types. Our method, called DEBT, is available online at http://comp.chem.nottingham.ac.uk/debt/.

2-Phenyl-7-(4-pyridylmethylamino-1,2,4-triazolo[1,5-a][1,3,5]triazin-5(4H-oneFused heterocyclic systems with s-triazine ring. Part 17. For part 16, see Dolzhenko et al. (2011.

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Lip Lin Koh

2011-01-01

Full Text Available In the title compound, C16H13N7O, the 1,2,4-triazolo[1,5-a][1,3,5]triazine heterocyclic system is essentially planar (r.m.s. deviation = 0.0375 Å. The attached benzene ring lies almost in the mean plane of 1,2,4-triazolo[1,5-a][1,3,5]triazine [dihedral angle = 1.36 (23°], while the pyridine ring is turned out of this plane by the aminomethyl bridge [dihedral angle = 69.22 (9°]. The amino group H atom is involved in intramolecular hydrogen bonding with a triazole N atom. In the crystal, molecules are connected via C(=ONH...N hydrogen bonds into C(11 chains parallel to [100]. The amino group H atom acts as a hydrogen-bond donor, forming an NH...O=C hydrogen bond with the carbonyl O atom, which links the molecules into C(6 chains running along [011] and [01overline{1}].

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.

Crystal structure of bromidobis(naphthalen-1-ylantimony(III

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Omar bin Shawkataly

2014-10-01

Full Text Available In the title compound, [SbBr(C10H72], the SbIII atom has a distorted trigonal–pyramidal coordination geometry and the planes of the two naphthalene ring systems make a dihedral angle of 80.26 (18°. An intramolecular C—H...Br hydrogen bond forms an S(5 ring motif. In the crystal, weak C—H...Br interactions link the molecules into helical chains along the b-axis direction.

N′-(But-2-enylideneisonicotinohydrazide

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Zhi-Gang Yin

2008-11-01

Full Text Available In the title Schiff base compound, C10H11N3O, the pyridine ring is twisted with respect to the mean plane containing the hydrazine chain, making a dihedral angle of 31.40 (9°. The NH group interacts with the N atom of the pyridine ring through N—H...N hydrogen bonds to build up a zigzag chain developing parallel to the (overline{1}01 plane.

(11-Methylpyrido[2,3-b][1,4]benzodiazepin-6-yl(phenylmethanone

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Fuqiang Shi

2010-09-01

Full Text Available In the title compound, C20H15N3O, the diazepine ring adopts a boat conformation. The dihedral angle between pyridine and benzene rings is 55.2 (1°. The benzoyl phenyl ring forms dihedral angles of 49.4 (1 and 75.9 (1°, respectively, with the pyridine and benzene rings. In the crystal, molecules are linked into centrosymmetric dimers by pairs of C—H...N hydrogen bonds.

(E-2-(5-Chloro-2-hydroxybenzylidene-N-cyclohexylhydrazine-1-carbothioamide

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Md. Azharul Arafath

2017-01-01

Full Text Available In the title compound, C14H18ClN3OS, the phenol ring is almost coplanar with the hydrazinecarbothioamide moiety, making a dihedral angle of 6.92 (8°. The cyclohexane ring has a chair conformation and the conformation about the C=N bond is E. In the crystal, molecules are linked by N—H...O and O—H...S hydrogen bonds, forming inversion dimers with an R22(14 ring motif flanked by two R22(6 ring motifs. The dimers are linked by short Cl...Cl interactions, forming layers parallel to the ab plane.

N-(2,6-Dimethyl-3-oxo-1-thia-4-azaspiro[4.5]dec-4-yl-2-hydroxy-2,2-diphenylacetamide

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Eser Ihan

2008-10-01

Full Text Available In the title compound, C24H28N2O3S, the pendant methyl C atom bonded to the cyclohexane ring is disordered over two sites in a 0.580 (11:0.420 (11 ratio. The cyclohexane ring adopts a distorted chair conformation while the thiazolidine ring has an envelope conformation. The two phenyl rings make a dihedral angle of 71.8 (2° with each other. The conformation is stabilized by an intramolecular N—H...O hydrogen bond. In the crystal structure, an intermolecular hydrogen bond O—H...O occurs.

(E-1-(4,4′′-Difluoro-5′-methoxy-1,1′:3′,1′′-terphenyl-4′-yl-3-(6-methoxynaphthalen-2-ylprop-2-en-1-one

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Hoong-Kun Fun

2011-12-01

Full Text Available In the title compound, C33H24F2O3, the central benzene ring makes dihedral angles of 44.71 (10, 47.80 (10 and 63.68 (9° with the two fluoro-substituted benzene rings and the naphthalene ring system, respectively. In the crystal, molecules are connected via intermolecular C—H...F and C—H...O hydrogen bonds. Furthermore, the crystal structure is stabilized by weak C—H...π and π–π interactions [centroid–centroid distance = 3.6816 (13 Å].

1,4-Dihexyloxy-2,5-bis(2-nitrophenylbenzene

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Norma Wrobel

2012-04-01

Full Text Available The title compound, C30H36N2O6, was prepared via twofold Suzuki coupling of a diboronic acid with bromonitrobenzene. The molecule is located on a crystallographic inversion centre. The lateral benzene ring and the central ring make a dihedral angle of 48.75 (14° and the nitro group is twisted by 41.47 (13° out of the plane of the benzene ring. The nitro and hexyloxy groups are in close proximity and the hexyloxy chain adopts an all-anti conformation.

Crystal structure of 3-({[(morpholin-4-yl)carbono­thio­yl]sulfan­yl}acet­yl)phenyl benzoate

Science.gov (United States)

Ambekar, Sachin P.; Mahesh Kumar, K.; Shirahatti, Arun Kumar M.; Kotresh, O.; Anil Kumar, G. N.

2014-01-01

In the title compound, C20H19NO4S2, the morpholine ring adopts the expected chair conformation. The central phenyl ring makes dihedral angles of 67.97 (4) and 7.74 (3)°, respectively, with the benzoate phenyl ring and the morpholine mean plane. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming zigzag chains along the b-axis direction. C—H⋯π inter­actions link centrosymmetrically related mol­ecules, reinforcing the three-dimensional structure. PMID:25484757

3-(Pyridin-2-ylcoumarin

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Yu-Xia Da

2010-11-01

Full Text Available In the title compound, C14H9NO2, the dihedral angle between the pyridine ring and the lactone ring is 10.40 (3°. The coumarin ring system is nearly planar, with a dihedral angle of 1.40 (2° between the lactone and benzene rings. An intramolecular C—H...O hydrogen bond occurs. In the crystal, inversion dimers linked by pairs of C—H...O interactions occur, generating R22(14 loops.

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

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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.

5-Ethyl-3-(2-fluorophenylsulfonyl-2-methyl-1-benzofuran

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Hong Dae Choi

2012-10-01

Full Text Available In the title compound, C17H15FO3S, the 2-fluorophenyl ring makes a dihedral angle of 89.12 (8° with the mean plane of the benzofuran fragment. In the crystal, molecules are linked by weak C—H...O and C—H...π interactions.

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

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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].

[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-[(E-(4-Fluorobenzylideneamino]benzoic acid

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Blanca M. Muñoz-Flores

2012-01-01

Full Text Available In the title compound, C14H10FNO2, the benzene rings make a dihedral angle of 57.50 (13°, and the molecule has an E configuration about the C=N bond. In the crystal, molecules are linked via pairs of O—H...O hydrogen bonds, forming inversion dimers.

11-[(E-Benzylidene]-14-hydroxy-8-phenyl-6-thia-3,13-diazaheptacyclo[13.7.1.19,13.02,9.02,14.03,7.019,23]tetracosa-1(22,15(23,16,18,20-pentaen-10-one

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Raju Suresh Kumar

2012-07-01

Full Text Available In the title compound, C34H28N2O2S, the piperidine ring adopts a chair conformation. One of the pyrrolidine rings adopts an envelope conformation with the methylene C atom at the flap whereas the other pyrrolidine ring and the thiazolidine ring adopt half-chair conformations. The mean plane of the dihydroacenaphthylene ring system [maximum deviation = 0.067 (1 Å] makes dihedral angles of 28.31 (5 and 31.32 (6° with the two terminal benzene rings. An intramolecular O—H...N hydrogen bond forms an S(5 ring motif. In the crystal, molecules are linked by C—H...O and C—H...S hydrogen bonds into layers lying parallel to the ac plane.

The crystal structure of 2-[5-(dimethylaminonaphthalene-1-sulfonamido]phenyl 5-(dimethylaminonaphthalene-1-sulfonate

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Kittipong Chainok

2015-10-01

Full Text Available The complete molecule of the title compound, C30H29N3O5S2, is generated by a crystallographic twofold axis: the O atom and NH group attached to the central benzene ring are statistically disordered. The dihedral angle between the naphthalene ring system and the central benzene ring is 52.99 (6°, while the pendant naphthalene ring systems subtend a dihedral angle of 68.17 (4°. An intramolecular C—H...O hydrogen bond closes an S(6 ring. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds.

3-Benzyl-6-bromo-2-(2-furyl-3H-imidazo[4,5-b]pyridine

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Younès Ouzidan

2010-07-01

Full Text Available In the title molecule, C17H12BrN3O, the imidazopyridine ring system is almost coplanar with the furan ring [dihedral angle = 2.0 (3°]. The benzyl phenyl ring is oriented at dihedral angles of 85.2 (2 and 85.5 (1°, respectively, with respect to the furan ring and the imidazopyridine ring system. In the crystal, molecules are linked into chains propagating along the b axis by C—H...N hydrogen bonds. Adjacent chains are linked via short Br...Br contacts [3.493 (1 Å].

5-Bromo-4-(3,4-dimethoxyphenylthiazol-2-amine

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Hazem A. Ghabbour

2012-06-01

Full Text Available In the title compound, C11H11BrN2O2S, the thiazole ring makes a dihedral angle of 53.16 (11° with the adjacent benzene ring. The two methoxy groups are slightly twisted from the attached benzene ring with C—O—C—C torsion angles of −9.2 (3 and −5.5 (3°. In the crystal, molecules are linked by a pair of N—H...N hydrogen bonds into an inversion dimer with an R22(8 ring motif. The dimers are further connected by N—H...O hydrogen bonds into a tape along [-110].

Crystal structure of ethyl (2S-9-methoxy-2-methyl-4-oxo-3,4,5,6-tetrahydro-2H- 2,6-methanobenzo[g][1,3,5]oxadiazocine-11-carboxylate

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A. Dhandapani

2015-02-01

Full Text Available In the title compound, C15H18N2O5, the methoxyphenyl ring makes a dihedral angle of 84.70 (12° with the mean plane of the tetrahydropyrimidin-2(1H-one ring. Both the pyran and tetrahydropyrimidin-2(1H-one rings have distorted envelope conformations with the carboxylate-substituted C atom as the flap. In the crystal, molecules are linked via pairs of N—H...O hydrogen bonds, forming zigzag chains propagating along [010], which enclose R22(8 ring motifs. The chains are linked by C—H...π interactions, forming a two-dimensional network parallel to (100.

(1′S-4-(3,4-Dichlorophenyl-1′-(3,5-dimethoxyphenyl-1,2,3,4-tetrahydronaphthalene-2-spiro-2′-pyrrolizidine-3′-spiro-3′′-indoline-1,2′′-dione

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S. Sriman Narayanan

2008-10-01

Full Text Available In the title compound C37H32Cl2N2O4, the unsubstituted pyrrolidine ring shows a twist conformation whereas the substituted pyrrolidine ring shows an envelope conformation. The dimethoxy benzene ring is perpendicular to the tetralone ring, making a dihedral angle of 89.94 (5°. Molecules are linked into centrosymmetric dimers by N—H...O hydrogen bonds and the crystal structure is stabilized by C—H...π interactions and C—H...O hydrogen bonds. One methoxy group is disordered over two positions with the site occupancy factors of 0.84 (2 and 0.16 (2.

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.

(4-Methylphenyl[2-(thiophen-2-ylcarbonylphenyl]methanone

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V. Silambarasan

2011-09-01

Full Text Available The crystal studied of the title compound, C19H14O2S, was an inversion twin with a 0.7 (1:0.3 (1 domain ratio. The central benzene ring makes dihedral angles of 63.31 (9 and 60.86 (9°, respectively, with the 4-methylphenyl and thiophene rings. In the crystal, molecules are linked by weak intermolecular C—H...O hydrogen bonds and S...π [3.609 (3 Å] interactions.

(Z-3-Benzyl-2-[(2-phenylcyclohex-2-enylimino]-1,3-thiazolidin-4-one

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Chin Wei Ooi

2012-08-01

Full Text Available The title compound, C22H22N2OS, exists in a Z configuration with respect to the N=C bond. The cyclohexene ring adopts a distorted sofa conformation. The thiazolidine ring is essentially planar, with a maximum deviation of 0.030 (2 Å, and forms dihedral angles of 76.66 (6 and 74.55 (6° with the terminal phenyl rings. The dihedral angle between the phenyl rings is 71.55 (7°. In the crystal, a C—H...π interaction is observed.

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

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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.

3-Methoxy-4-(4-nitrobenzyloxybenzaldehyde

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Xin Chen

2008-12-01

Full Text Available In the title compound, C15H13NO5, the vanillin group makes a dihedral angle of 4.95 (8° with the benzene ring of the nitrobenzene group. The packing is stabilized by weak, non-classical intermolecular C—H...O interactions which link molecules into chains running along the c axis.

Crystal structure of (E-N-phenyl-N′-[1-(thiophen-2-ylethylidene]formohydrazide

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C. S. Dileep

2014-09-01

Full Text Available In the title compound, C13H12N2OS, the planes of the thiophene and phenyl rings are nearly perpendicular to each other, making a dihedral angle of 86.42 (12°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a helical chain along the b-axis direction.

Ethyl 27-oxo-15-oxa-2,20-diazahexacyclo[18.6.1.01,8.02,6.09,14.021,26]heptacosa-9,11,13,21,23,25-hexaene-7-carboxylate

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Devadasan Velmurugan

2013-01-01

Full Text Available In the title compound, C27H30N2O4, the pyrrolidine ring adopts a twisted conformation. The indoline ring system is almost perpendicular to the mean plane of the pyrrolidine ring, making a dihedral angle of 81.7 (8°. In the crystal, molecules are linked into centrosymmetric dimers with graph-set motif R22(16 via pairs of C—H...O hydrogen bonds. The terminal ethyl group of the ester group is disordered over two sets of sites, with a site-occupancy ratio of 0.587 (11:0.413 (11.

Crystal structure of (E-4-{2-[4-(allyloxyphenyl]diazenyl}benzoic acid

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Md. Lutfor Rahman

2014-12-01

Full Text Available The title compound, C16H14N2O3, has an E conformation about the azobenzene [—N=N– = 1.2481 (16 Å] linkage. The benzene rings are almost coplanar [dihedral angle = 1.36 (7°]. The O atoms of the carboxylic acid group are disordered over two sets of sites and were refined with an occupancy ratio of 0.5:0.5. The two disordered components of the carboxylic acid group make dihedral angles of 1.5 (14 and 3.8 (12° with the benzene ring to which they are attached. In the crystal, molecules are linked via pairs of O—H...O hydrogen bonds, forming inversion dimers. The dimers are connected via C—H...O hydrogen bonds, forming ribbons lying parallel to [120]. These ribbons are linked via C—H...π interactions, forming slabs parallel to (001.

2-(1H-Benzimidazol-2-ylphenol

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S. M. Prakash

2014-02-01

Full Text Available The title molecule, C13H10N2O, is essentially planar, the maximum deviation from the plane of the non-H atoms being 0.016 (2 Å. The imidazole ring makes a dihedral angle of 0.37 (13° with the attached benzene ring. An intramolecular O—H...N hydrogen bond generates an S(6 ring motif. In the crystal, molecules are linked through N—H...O hydrogen bonds, forming chains propagating in [001]. The crystal packing also features four π–π stacking interactions involving the imidazole ring, fused benzene ring and attached benzene ring system [centroid–centroid distances = 3.6106 (17, 3.6108 (17, 3.6666 (17 and 3.6668 (17 Å].

4-{2-Methoxy-6-[(4-methylphenyliminomethyl]phenoxy}phthalonitrile

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Orhan Büyükgüngör

2009-05-01

Full Text Available In the molecule of the title compound, C23H17N3O2, the methoxyphenyl ring is oriented at dihedral angles of 13.34 (12 and 88.83 (12° with respect to the methylphenyl and phthalonitrile rings, respectively; the dihedral angle between methylphenyl and phthalonitrile rings is 89.67 (10°. In the crystal structure, weak intermolecular C—H...N interactions link molecules into chains. A weak C—H...π interaction is also found..

Pairwise NMR experiments for the determination of protein backbone dihedral angle Φ based on cross-correlated spin relaxation

International Nuclear Information System (INIS)

Takahashi, Hideo; Shimada, Ichio

2007-01-01

Novel cross-correlated spin relaxation (CCR) experiments are described, which measure pairwise CCR rates for obtaining peptide dihedral angles Φ. The experiments utilize intra-HNCA type coherence transfer to refocus 2-bond J NCα coupling evolution and generate the N (i)-C α (i) or C'(i-1)-C α (i) multiple quantum coherences which are required for measuring the desired CCR rates. The contribution from other coherences is also discussed and an appropriate setting of the evolution delays is presented. These CCR experiments were applied to 15 N- and 13 C-labeled human ubiquitin. The relevant CCR rates showed a high degree of correlation with the Φ angles observed in the X-ray structure. By utilizing these CCR experiments in combination with those previously established for obtaining dihedral angle Ψ, we can determine high resolution structures of peptides that bind weakly to large target molecules

4-Methyl-N-(1-methyl-1H-indazol-5-ylbenzenesulfonamide

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Hakima Chicha

2013-09-01

Full Text Available In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2 Å, and makes a dihedral angle of 48.84 (9° with the benzene ring belonging to the methylbenzenesulfonamide moiety. In the crystal, molecules are connected through N—H...N hydrogen bonds and weak C—H...O contacts, forming a two-dimensional network parallel to (001.

2-(4-Methylphenyl-5-[({[5-(4-methylphenyl-1,3,4-thiadiazol-2-yl]sulfanyl}methylsulfanyl]-1,3,4-thiadiazole

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Jing-wen Yu

2012-03-01

Full Text Available In the title compound, C19H16N4S4, the molecules exhibit a butterfly conformation, where the thiadiazole and attached benzene rings in two wings are almost coplanar, with dihedral angles of 0.8 (3 and 0.9 (3°, respectively, while the two thiadiazole rings form a dihedral angle of 46.3 (3°.

3-(4-Chlorobenzoyl-4-(4-chlorophenyl-1-phenethylpiperidin-4-ol

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Abdullah Aydın

2011-06-01

Full Text Available In the title compound, C26H25Cl2NO2, the piperidine ring adopts a chair conformation with a cis configuration of the carbonyl and hydroxy substituents. The dihedral angle between the aromatic rings of the chlorobenzene groups is 24.3 (2°. The phenyl ring forms dihedral angles of 59.4 (3 and 44.1 (3° with the benzene rings. In the crystal, molecules are linked by intermolecular O—H...N and C—H...O hydrogen bonds and C—H...π interactions into layers parallel to the bc plane.

6,7-Dichloro-3-(2,4-dichlorobenzylquinoxalin-2(1H-one

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Jinpeng Zhang

2012-08-01

Full Text Available In the title compound, C15H8Cl4N2O, the quinoxaline ring system is almost planar, with a dihedral angle between the benzene and pyrazine rings of 3.1 (2°. The 2,4-dichlorophenyl ring is approximately perpendicular to the pyrazine ring, with a dihedral angle of 86.47 (13° between them. The crystal packing features intermolecular N—H...O hydrogen bonds and π–π stacking interactions, with centroid–centroid distances in the range 3.699 (3–4.054 (3 Å.

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-[(3-Phenyl-4,5-dihydroisoxazol-5-ylmethyl]-2H-benzo[b][1,4]thiazin-3(4H-one

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Nada Kheira Sebbar

2016-06-01

Full Text Available In the title compound, C18H16N2O2S, the 5-dihydroisoxazol-5-yl ring and its phenyl substituent are nearly coplanar, with the largest deviation from the mean plane being 0.0184 (16 Å. The thiomorpholin-3-one ring adopts a screw-boat conformation and the attached benzene ring makes a dihedral angle of 42.26 (7° with the mean plane through the 3-phenyl-4,5-dihydroisoxazol-5-yl ring system. In the crystal, molecules are linked by pairs of C—H...N hydrogen bonds, forming inversion dimers. These dimers are linked via C—H...O hydrogen bonds, generating a three-dimensional network.

The power of hard-sphere models: explaining side-chain dihedral angle distributions of Thr and Val.

Science.gov (United States)

Zhou, Alice Qinhua; O'Hern, Corey S; Regan, Lynne

2012-05-16

The energy functions used to predict protein structures typically include both molecular-mechanics and knowledge-based terms. In contrast, our approach is to develop robust physics- and geometry-based methods. Here, we investigate to what extent simple hard-sphere models can be used to predict side-chain conformations. The distributions of the side-chain dihedral angle χ(1) of Val and Thr in proteins of known structure show distinctive features: Val side chains predominantly adopt χ(1) = 180°, whereas Thr side chains typically adopt χ(1) = 60° and 300° (i.e., χ(1) = ±60° or g- and g(+) configurations). Several hypotheses have been proposed to explain these differences, including interresidue steric clashes and hydrogen-bonding interactions. In contrast, we show that the observed side-chain dihedral angle distributions for both Val and Thr can be explained using only local steric interactions in a dipeptide mimetic. Our results emphasize the power of simple physical approaches and their importance for future advances in protein engineering and design. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

3,6-Dibromo-9-(4-tert-butylbenzyl-9H-carbazole

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Duan-Lin Cao

2008-08-01

Full Text Available In the title compound, C23H21Br2N, which was synthesized by the N-alkylation of 1-tert-butyl-4-(chloromethylbenzene with 3,6-dibromo-9H-carbazole, the asymmetric unit contains two unique molecules. Each carbazole ring system is essentially planar, with mean deviations of 0.0077 and 0.0089 Å for the two molecules. The carbazole planes make dihedral angles of 78.9 (2 and 81.8 (2° with the planes of the respective benzene rings.

3-Ethylsulfinyl-2-(4-iodophenyl-5-methyl-1-benzofuran

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Hong Dae Choi

2010-08-01

Full Text Available In the title compound, C17H15IO2S, the 4-iodophenyl ring makes a dihedral angle of 35.39 (8° with the plane of the benzofuran fragment. In the crystal, molecules are linked by intermolecular C—H...O and C—H...π interactions, and an I...O contact [3.378 (2 Å]. The crystal structure also exhibits aromatic π–π interactions between the benzene rings of neighbouring molecules [centroid–centroid distance = 3.495 (3 Å].

4-Methyl-N-(1-methyl-1H-indazol-5-yl)benzene­sulfonamide

Science.gov (United States)

Chicha, Hakima; Oulemda, Bassou; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

In the title compound, C15H15N3O2S, the fused ring system is close to planar, the largest deviation from the mean plane being 0.030 (2) Å, and makes a dihedral angle of 48.84 (9)° with the benzene ring belonging to the methyl­benzene­sulfonamide moiety. In the crystal, mol­ecules are ­connected through N—H⋯N hydrogen bonds and weak C—H⋯O contacts, forming a two-dimensional network parallel to (001). PMID:24427093

4-Methylbenzenecarbothioamide

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Saqib Ali

2010-06-01

Full Text Available In the title molecule, C8H9NS, the mean plane of the carbothioamide group is twisted slightly with respect to the mean plane of the benzene ring, making a dihedral angle of 17.03 (10°. The crystal structure is stabilized by intermolecular N—H...S hydrogen bonds, resulting in the formation of eight-membered rings lying about inversion centers and representing R22(8 and R42(8 motifs. Futhermore, these hydrogen bonds build up chains parallel to the b axis.

4-Hydroxy-6-methyl-3-[3-(thiophen-2-ylacryloyl]-2H-pyran-2-one

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Salima Thabti

2013-04-01

Full Text Available The title compound, C13H10O4S, crystallizes with two molecules in the asymmetric unit in which the rings make dihedral angles of 3.9 (1 and 6.0 (1°; this planarity is due in part to the presence of an intramolecular O—H...O hydrogen bond, which generates an S(6 ring in each molecule. Both molecules represent E isomers with respect to the central C=C bond. In the crystal, molecules are linked by C—H...O interactions into a three-dimensional network.

N,N′-Bis[3,5-bis(2,6-diisopropylphenylphenyl]butane-2,3-diimine

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Tracy L. Lohr

2011-09-01

Full Text Available The title molecule, C64H80N2, lies on an inversion center wherein the central butanediimine fragment [N=C(Me—C(Me=N] is essentially planar [maximum deviation = 0.002 (2 Å] and its mean plane forms a dihedral of 70.88 (10° with the attached benzene ring. In the symmetry-unique part of the molecule, the dihedral angles between the benzene ring bonded to the N atom and the other two benzene rings are 89.61 (6 and 82.77 (6°.

(E-4-(2,5-Dimethoxybenzylidene-2-phenyl-1,3-oxazol-5(4H-one

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Abdullah Mohamed Asiri

2009-08-01

Full Text Available The central azalactone ring in the title compound, C18H15NO4, is planar (r.m.s. deviation 0.05, 0.12 Å in both independent molecules comprising the asymmetric unit. The benzylidene substituent is coplanar with this ring [dihedral angle between the planes = 1.8 (1° in the first molecule and 2.8 (1° in the second], as is the phenyl substitutent [dihedral angle between rings = 4.6 (1 and 9.7 (1°, respectively].

(1-Phenyl-1H-1,2,3-triazol-4-ylmethyl pyridine-3-carboxylate

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Zakirjon Karimov

2010-07-01

Full Text Available In the title compound, C15H12N4O2, the dihedral angle between the planes of the nicotinoyloxy fragment and triazole ring is 88.61 (5°. The dihedral angle between the planes of triazole and benzene rings is 16.54 (11°. The crystal structure is stabilized by intermolecular C—H...N, C—H...O and C—H...π(triazole hydrogen bonds and aromatic π–π stacking interactions between the benzene and triazole rings [centroid–centroid distance = 3.895 (1 Å

Normal mode analysis based on an elastic network model for biomolecules in the Protein Data Bank, which uses dihedral angles as independent variables.

Science.gov (United States)

Wako, Hiroshi; Endo, Shigeru

2013-06-01

We have developed a computer program, named PDBETA, that performs normal mode analysis (NMA) based on an elastic network model that uses dihedral angles as independent variables. Taking advantage of the relatively small number of degrees of freedom required to describe a molecular structure in dihedral angle space and a simple potential-energy function independent of atom types, we aimed to develop a program applicable to a full-atom system of any molecule in the Protein Data Bank (PDB). The algorithm for NMA used in PDBETA is the same as the computer program FEDER/2, developed previously. Therefore, the main challenge in developing PDBETA was to find a method that can automatically convert PDB data into molecular structure information in dihedral angle space. Here, we illustrate the performance of PDBETA with a protein-DNA complex, a protein-tRNA complex, and some non-protein small molecules, and show that the atomic fluctuations calculated by PDBETA reproduce the temperature factor data of these molecules in the PDB. A comparison was also made with elastic-network-model based NMA in a Cartesian-coordinate system. Copyright © 2013 Elsevier Ltd. All rights reserved.

6-Hydroxy-5-[(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl(4-nitrophenylmethyl]-1,3-dimethylpyrimidine-2,4(1H,3H-dione

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N. Sureshbabu

2013-11-01

Full Text Available In the title compound, C21H23N3O7, the pyrimidinedione ring adopts a screw-boat conformation, whereas the cyclohexenone ring adopts an envelope conformation, with the C atom bearing the methyl groups as the flap atom. The dihedral angle between the mean planes of the pyrimidinedione and cyclohexenone rings is 58.78 (2°. The pyrimidinedione and cyclohexenone rings form dihedral angles of 59.94 (3 and 54.73 (2°, respectively, with the 4-nitrophenyl ring. Relatively strong intramolecular O—H...O hydrogen bonds are observed. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a chain along the c-axis direction.

N-(2,4-Dichlorophenyl-1,3-thiazol-2-amine

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Ayesha Babar

2012-09-01

Full Text Available In the title molecule, C9H6Cl2N2S, the mean planes of the benzene and thiazole rings make a dihedral angle of 54.18 (8°. In the crystal, molecules are joined into dimers with an R22(8 ring motif by pairs of N—H...N hydrogen bonds. These dimers are linked by C—H...Cl interactions into layers parallel to (011. The thiazole rings form columns along the c-axis direction, with a centroid–centroid separation of 3.8581 (9 Å, indicating π–π interactions. An intramolecular C—H...S contact also occurs.

Ethyl 2-(6-bromo-2-phenyl-1H-imidazo[4,5-b]pyridin-1-ylacetate

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Mohammed Yassin Hjouji

2016-05-01

Full Text Available In the title compound, C16H14BrN3O2, the fused-ring system is essentially planar, with the largest deviation from the mean plane being 0.0216 (15 Å for the substituted N atom of the five-membered ring, the plane of which makes dihedral angles of 28.50 (7 and 77.48 (7° with the terminal phenyl ring and the ethoxycarbonylmethyl group mean planes, respectively. In the crystal, C—H...N hydrogen bonds link the molecules into inversion dimers. These combine with weak C—H...N contacts to stack the molecules into columns along the b-axis direction.

(2E-3-(4-Chlorophenyl-1-(4-hydroxyphenylprop-2-en-1-one

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Jerry P. Jasinski

2011-04-01

Full Text Available In the title compound, C15H11ClO2, the dihedral angle between the mean planes of the chlorobenzene and hydroxybenzene rings is 6.5 (6°. The mean plane of the prop-2-en-1-one group makes an angle of 18.0 (1° with the hydroxyphenyl ring and 11.5 (1° with the chlorophenyl ring. The crystal packing is stabilized by intermolecular O—H...O hydrogen bonds, weak C—H...O, C—H...π and π–π stacking interactions [centroid–centroid distances = 3.7771 (7 and 3.6917 (7 Å].

2-{4-Methyl-N-[(2,3,4,9-tetrahydro-1H-carbazol-3-ylmethyl]benzenesulfonamido}ethyl 4-methylbenzenesulfonate

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Nagihan Çaylak Delibaş

2013-12-01

Full Text Available In the title compound, C29H32N2O5S2, the indole ring system is nearly planar, with a maximum deviation of 0.013 (2 Å, and the cyclohexenone ring has an envelope conformation with the methine C atom as the flap. The two methylbenzene rings are approximately perpendicular to each other, making a dihedral angle of 89.09 (8°. In the crystal, N—H...O hydrogen bonds link the molecules into a chain running along the a-axis direction, and weak C—H...O hydrogen bonds and C—H...π interactions are observed between the chains.

4-[(E-({4-[(4-Aminophenylsulfonyl]phenyl}iminomethyl]phenol ethanol monosolvate

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Sadaf Afzal

2012-06-01

Full Text Available In the title compound, C19H16N2O3S·C2H6O, the 4-hydroxybenzylidene group is oriented at dihedral angles of 73.17 (7 and 77.06 (7° with respect to the aniline groups. The sulfonyl group make dihedral angles of 44.89 (13 and 59.16 (12° with the adjacent aniline groups. In the crystal, a two-dimensional polymeric network parallel to (010 is formed by N—H...O, O—H...N and O—H...O hydrogen bonds. There also exist π–π interactions with a distance of 3.5976 (18 Å between the centroids of hydroxyphenyl rings.

[meso-5,10,15,20-Tetrakis(5-bromothiophen-2-ylporphyrinato-κ4N,N′,N′′,N′′′]nickel(II

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R. Prasath

2012-04-01

Full Text Available The NiII atom in the title porphyrin complex, [Ni(C36H16Br4N4S4], is in a square-planar geometry defined by four pyrrole N atoms. There is considerable buckling in the porphyrin ring with the dihedral angles between the N4 donor set and the pyrrole rings being in the range 17.0 (3–18.8 (3°. Each of the six-membered chelate rings is twisted about an Ni—N bond and the dihedral angles between diagonally opposite chelate rings are 13.08 (15 and 13.45 (11°; each pair of rings is orientated in opposite directions. The bromothienyl rings are twisted out of the plane of the central N4 core with dihedral angles in the range 51.7 (2–74.65 (19°. Supramolecular chains along [001] are formed through C—H...Br interactions in the crystal packing. Three of the four bromothienyl units are disordered over two coplanar positions of opposite orientation with the major components being in 0.691 (3, 0.738 (3 and 0.929 (9 fractions.

On some homological functors of Bieberbach group of dimension four with dihedral point group of order eight

Science.gov (United States)

Mohammad, Siti Afiqah; Ali, Nor Muhainiah Mohd; Sarmin, Nor Haniza; Idrus, Nor'ashiqin Mohd; Masri, Rohaidah

2014-06-01

A Bieberbach group is a torsion free crystallographic group, which is an extension of a free abelian group of finite rank by a finite point group, while homological functors of a group include nonabelian tensor square, exterior square and Schur Multiplier. In this paper, some homological functors of a Bieberbach group of dimension four with dihedral point group of order eight are computed.

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.

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

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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.

Crystal structure of 2,3-bis(4-methylphenylbenzo[g]quinoxaline

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Young-Inn Kim

2018-04-01

Full Text Available The title compound, C26H20N2, was obtained during a search for new π-extended ligands with the potential to generate efficient phosphors with iridium(III for organic light-emitting devices (OLEDs. The benzoquinoxaline ring system is almost planar (r.m.s. deviation = 0.076 Å. A pseudo-twofold rotation axis runs through the midpoints of the C2—C3 and C9—C10 bonds. The two phenyl rings are twisted relative to the benzoquinoxaline ring system, making dihedral angles of 53.91 (4 and 36.86 (6°. In the crystal, C—H...π (arene interactions link the molecules, but no π–π interactions between aromatic rings are observed.

(3R,4R,4aS,7aR,12bS-3-Cyclopropylmethyl-4a,9-dihydroxy-3-methyl-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide

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Xiangfeng Chen

2012-02-01

Full Text Available The title compound, C21H26NO4+·Br−, also known as R-methylnaltrexone (MNTX bromide, is a selective peripherally acting μ-opioid receptor antagonist with a oroxymorphone skeleton, synthesized by hydroxyl protection, N-methylation, deprotection and anion exchange of naltrexone. It comprises a five-ring system A/B/C/D/E. Rings C and E adopt distorted chair conformations, whereas ring D is in half-chair conformation. The C/E ring junctions are trans fused. The dihedral angle between rings D and E is 82.3 (1°, while the dihedral angles between the planes of rings C and A, and rings D and E are respectively 81.7 (1, 75.9 (1 and 12.2 (1°. In the crystal, molecules are linked by O—H...Br hydrogen bonds.

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.

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.

4′-Methyl-14′,19′-dioxa-4′-azaspiro[acenaphthylene-1,5′-tetracyclo[18.4.0.02,6.08,13]tetracosane]-1′(24′,8′,10′,12′,20′,22′-hexaene-2,7′(1H-dione

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Sibi Narayanan

2012-12-01

Full Text Available In the title compound, C33H29NO4, the acenaphthylene ring system is essentially planar (r.m.s. deviation = 0.0290 Å. The pyrrolidine ring adopts a C-envelope conformation with a C atom displaced by 0.671 (2 Å from the mean-plane formed by the remaining ring atoms. The pyrrolidine ring is fused to acenaphthylene ring system making a dihedral angle of 88.0 (7°. In the crystal, molecules are linked into R22(9 dimers via C—H...N and C—H...O hydrogen bonds. Two C atoms act as donors to the same O atom acceptor, resulting in the formation of R21(7 ring motifs. These two motifs combine to form hydrogen-bonded sheets running along the a- and b-axis directions.

Crystal structure of (E-2-benzylidene-4-[(3-phenyl-4,5-dihydroisoxazol-5-ylmethyl]-2H-benzo[b][1,4]thiazin-3(4H-one

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Nada Kheira Sebbar

2015-06-01

Full Text Available In the title compound, C25H20N2O2S, the dihydroisoxazole ring exhibits an envelope conformation with the methine atom being the flap, while the 1,4-thiazine ring displays a screw-boat conformation. The six-membered ring fused to the 1,4-thiazine ring makes dihedral angles of 63.04 (2 and 54.7 (2° with the mean planes through the five-membered heterocycle and the attached phenyl ring, respectively. The phenyl group connected to the 1,4-thiazine ring is disordered over two sites [major component = 0.57 (2]. The most prominent interactions in the crystal structure are C—H...O hydrogen bonds that link molecules, forming inversion dimers, and C—H...N hydrogen bonds that link the dimers into columns parallel to the b axis.

Crystal structures of (Z-5-[2-(benzo[b]thiophen-2-yl-1-(3,5-dimethoxyphenylethenyl]-1H-tetrazole and (Z-5-[2-(benzo[b]thiophen-3-yl-1-(3,4,5-trimethoxyphenylethenyl]-1H-tetrazole

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Narsimha Reddy Penthala

2016-05-01

Full Text Available (Z-5-[2-(Benzo[b]thiophen-2-yl-1-(3,5-dimethoxyphenylethenyl]-1H-tetrazole methanol monosolvate, C19H16N4O2S·CH3OH, (I, was prepared by the reaction of (Z-3-(benzo[b]thiophen-2-yl-2-(3,5-dimethoxyphenylacrylonitrile with tributyltin azide via a [3 + 2]cycloaddition azide condensation reaction. The structurally related compound (Z-5-[2-(benzo[b]thiophen-3-yl-1-(3,4,5-trimethoxyphenylethenyl]-1H-tetrazole, C20H18N4O3S, (II, was prepared by the reaction of (Z-3-(benzo[b]thiophen-3-yl-2-(3,4,5-trimethoxyphenylacrylonitrile with tributyltin azide. Crystals of (I have two molecules in the asymmetric unit (Z′ = 2, whereas crystals of (II have Z′ = 1. The benzothiophene rings in (I and (II are almost planar, with r.m.s deviations from the mean plane of 0.0084 and 0.0037 Å in (I and 0.0084 Å in (II. The tetrazole rings of (I and (II make dihedral angles with the mean planes of the benzothiophene rings of 88.81 (13 and 88.92 (13° in (I, and 60.94 (6° in (II. The dimethoxyphenyl and trimethoxyphenyl rings make dihedral angles with the benzothiophene rings of 23.91 (8 and 24.99 (8° in (I and 84.47 (3° in (II. In both structures, molecules are linked into hydrogen-bonded chains. In (I, these chains involve both tetrazole and methanol, and are parallel to the b axis. In (II, molecules are linked into chains parallel to the a axis by N—H...N hydrogen bonds between adjacent tetrazole rings.

Classification Formula and Generation Algorithm of Cycle Decomposition Expression for Dihedral Groups

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Dakun Zhang

2013-01-01

Full Text Available The necessary of classification research on common formula of group (dihedral group cycle decomposition expression is illustrated. It includes the reflection and rotation conversion, which derived six common formulae on cycle decomposition expressions of group; it designed the generation algorithm on the cycle decomposition expressions of group, which is based on the method of replacement conversion and the classification formula; algorithm analysis and the results of the process show that the generation algorithm which is based on the classification formula is outperformed by the general algorithm which is based on replacement conversion; it has great significance to solve the enumeration of the necklace combinational scheme, especially the structural problems of combinational scheme, by using group theory and computer.

2-Chloro-N-(3-chlorophenylbenzamide

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B. Thimme Gowda

2008-07-01

Full Text Available In the structure of the the title compound, C13H9Cl2NO, the N—H and C=O groups are mutually trans. Furthermore, the conformation of the C=O group is syn to the ortho-chloro group in the benzoyl ring, while the N—H bond is anti to the meta-chloro group in the aniline ring. The amide group forms dihedral angles of 89.11 (19 and 22.58 (37°, respectively, with the benzoyl and aniline rings, while the benzoyl and aniline rings form a dihedral angle of 69.74 (14°. The molecules are linked into infinite chains through intermolecular N—H...O hydrogen bonds.

4-(2,4-Dichlorophenyl-6-(1H-indol-3-yl-2,2′-bipyridine-5-carbonitrile

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M. N. Ponnuswamy

2009-05-01

Full Text Available The title compound, C25H14Cl2N4, crystallizes with two independent molecules in the asymmetric unit. The two pyridine rings are almost coplanar, making dihedral angles of 3.2 (1 and 8.6 (1° in the two independent molecules. The dichlorophenyl and indole rings are twisted away from the bipyridine ring by 64.32 (5 and 18.46 (4°, respectively in the first molecule and by 51.0 (1 and 27.99 (5°, respectively in the second molecule. The crystal packing is stabilized by C—H...N, C—H...Cl, N—H...N and C—H...π interactions.

3-{2-[2-(2-Fluorobenzylidenehydrazinyl]-1,3-thiazol-4-yl}-2H-chromen-2-one

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Afsheen Arshad

2010-06-01

Full Text Available In the title compound, C19H12FN3O2S, the chromene ring system and the thiazole ring are approximately planar [maximum deviations of 0.023 (3 Å and 0.004 (2 Å, respectively]. The chromene ring system is inclined at angles of 4.78 (10 and 26.51 (10° with respect to the thiazole and benzene rings, respectively, while the thiazole ring makes a dihedral angle of 23.07 (12° with the benzene ring. The molecular structure is stabilized by an intramolecular C—H...O hydrogen bond, which generates an S(6 ring motif. The crystal packing is consolidated by intermolecular N—H...O hydrogen bonds, which link the molecules into chains parallel to [100], and by C—H...π and π–π [centroid–centroid distance = 3.4954 (15 Å] stacking interactions.

New Main Ring control system

International Nuclear Information System (INIS)

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

1990-03-01

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

Resorcinol ninhydrin complex: 1,5,9-trihydroxy-8-oxatetracyclo[7.7.0.02,7.010,15]hexadeca-2,4,6,10(15,11,13-hexaen-16-one

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B. Sridhar

2012-05-01

Full Text Available In the title compound, C15H10O5, the cyclopentanone (r.m.s. deviation = 0.049 Å and oxolane (r.m.s. deviation = 0.048 Å rings make a dihedral angle of 67.91 (4°. An intramolecular O—H...O hydrogen bond is observed. In the crystal, molecules associate via O—H...O hydrogen bonds, forming a three-dimensional network.

3,3′-Di-n-butyl-1,1′-(p-phenylenedimethylenediimidazolium bis(hexafluorophosphate

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Rosenani A. Haque

2010-04-01

Full Text Available The asymmetric unit of the title N-heterocyclic carbene compound, C22H32N42+·2PF6−, consists of one half of the N-heterocyclic carbene dication and one hexafluorophosphate anion. The dication lies across a crystallographic inversion center. The imidazole ring is twisted away from the central benzene ring, making a dihedral angle of 76.23 (6°. The hexafluorophosphate anions link the cations into a three-dimensional network via intermolecular C—H...F hydrogen bonds. A weak C—H...π interaction further stabilizes the crystal structure.

4-{3-[Hydroxy(phenylmethyl]-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-4-yl}benzenesulfonamide

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Mehmet Akkurt

2010-04-01

Full Text Available In the title compound, C15H14N4O3S2, the hydroxy group is disordered over two positions with occupancies of 0.619 (5 and 0.381 (5. The benzene ring attached to the heterocycle makes a dihedral angle of 86.92 (9° with respect to the best plane through the five-membered ring. The crystal packing is stabilized by intermolecular O—H...O, N—H...S, N—H...N, C—H...O and C—H...N hydrogen bonds, and N—H...π and C—H...π interactions.

2,3-Bis[(3-methylbiphenyl-4-ylimino]butane

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Jingjing Chen

2014-04-01

Full Text Available The title compound, C30H28N2, is a product of the condensation reaction of 2-methyl-4-phenylaniline and butane-2,3-dione. The molecule lies on a crystallographic inversion centre. The C=N bond has an E conformation. The dihedral angle between the two benzene rings of the 4-phenyl-2-methylphenyl group is 29.19 (76°. The 1,4-diazabutadiene plane makes an angle of 70.1 (10° with the N-bonded methylphenyl ring and an angle of 81.08 (97° with the terminal phenyl group.

Crystal structure of 5-[(4-carboxybenzyloxy]isophthalic acid

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Md. Serajul Haque Faizi

2016-08-01

Full Text Available The molecular shape of the title compound, C16H12O7, is bent around the central CH2—O bond. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 87.78 (7°. In the crystal, each molecule is linked to three others by three pairs of O—H...O hydrogen bonds, forming undulating sheets parallel to the bc plane and enclosing R22(8 ring motifs. The sheets are linked by C—H...O hydrogen bonds and C—H...π interactions, forming a three-dimensional network.

Search for electric dipole moments in storage rings

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Lenisa Paolo

2016-01-01

Full Text Available The JEDI collaboration aims at making use of storage ring to provide the most precise measurement of the electric dipole moments of hadrons. The method makes exploits a longitudinal polarized beam. The existence an electric dipole moment would generate a torque slowly twisting the particle spin out of plan of the storage ring into the vertical direction. The observation of non zero electric dipole moment would represent a clear sign of new physics beyond the Standard Model. Feasiblity tests are presently undergoing at the COSY storage ring Forschungszentrum Jülich (Germany, to develop the novel techniques to be implemented in a future dedicated storage ring.

1-(4-Methyl­phenyl­sulfon­yl)-5,6-di­nitro-1H-indazole

Science.gov (United States)

Oulemda, Bassou; Rakib, El Mostapha; Abbassi, Najat; Saadi, Mohamed; El Ammari, Lahcen

2014-01-01

In the title compound, C14H10N4O6S, the indazole ring system is almost perpendicular to the tosyl ring, as indicated by the dihedral angle of 89.40 (9)° between their planes. The dihedral angles between the indazole system and the nitro groups are 57.0 (3) and 31.9 (3)°. In the crystal, mol­ecules are linked by C—H⋯O inter­actions, forming chains running along [100]. PMID:24526962

1-(4-Methylphenylsulfonyl-5,6-dinitro-1H-indazole

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Bassou Oulemda

2014-01-01

Full Text Available In the title compound, C14H10N4O6S, the indazole ring system is almost perpendicular to the tosyl ring, as indicated by the dihedral angle of 89.40 (9° between their planes. The dihedral angles between the indazole system and the nitro groups are 57.0 (3 and 31.9 (3°. In the crystal, molecules are linked by C—H...O interactions, forming chains running along [100].

2-Carboxy-6-(quinolin-1-ium-8-yloxybenzoate

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Jin Xie

2012-05-01

Full Text Available In the zwitterionic title compound, C17H11NO5, the dihedral angle between the two aromatic rings is 76.90 (7°. The dihedral angles between the carboxyl groups and the benzene ring are 64.02 (9 and 21.67 (9°, the larger angle being associated with an intramolecular N—H...Ocarboxyl hydrogen bond, resulting from proton transfer from the carboxylic acid group to the quinoline N atom and giving an S(9 ring motif. In the crystal, molecules are connected by O—H...O hydrogen bonds into chains extending along the b-axis direction. An overall two-dimensional network structure is formed through π–π interactions between the quinoline rings [minimum ring-centroid separation = 3.6068 (6 Å].

2,6-Diphenyl-4-(2-thienyl-1,4-dihydropyridine-3,5-dicarbonitrile

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Xiao-Tong Zhu

2009-09-01

Full Text Available The asymmetric unit of the title compound, C23H15N3S, contains two crystallographically independent molecules. The pyridine rings adopt envelope conformations. The thiophene rings are oriented at dihedral angles of 77.97 (4/53.53 (4 and 78.44 (4/57.11 (4° with respect to the phenyl rings, while the dihedral angles between the phenyl rings are 48.51 (4 and 44.49 (4°. In the crystal structure, intermolecular N—H...N hydrogen bonds link the molecules into chains along the c axis. The S, C and H atoms of one of the thiophene rings are disordered over two orientations, with occupancy ratios of 0.314 (15:0.686 (15.

Methyl 11-hydroxy-9-[1-(4-methoxyphenyl-4-oxo-3-phenoxyazetidin-2-yl]-18-oxo-10-oxa-2-azapentacyclo[9.7.0.01,8.02,6.012,17]octadeca-12(17,13,15-triene-8-carboxylate

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S. Sundaramoorthy

2012-07-01

Full Text Available In the title compound, C34H32N2O8, one of the pyrrolidine rings in the pyrrolizidine ring system adopts a twist conformation, whereas the other ring adopts an envelope conformation (C atom as flap. The five-membered ring in the indene ring system and the fused furan ring also adopt envelope conformations (C and O atoms as flaps, respectively. The β-lactam ring makes dihedral angles of 23.41 (2 and 25.98 (2°, respectively, with the attached methoxyphenyl and phenoxy rings. The molecular conformation is stabilized by an intramolecular O—H...N hydrogen bond, generating an S(5 motif. In the crystal, molecules are linked into C(12 chains running along the a axis by C—H...O hydrogen bonds. The structure is further consolidated by weak intermolecular C—H...π and π–π interactions [centroid–centroid distance = 3.7987 (14 Å].

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.)

N-{(2S-3-Hydroxy-4-[(5-methyl-1,3,4-thiadiazol-2-ylsulfanyl]-1-phenyl-2-butyl}-4-methylbenzenesulfonamide

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Claudia R. B. Gomes

2011-09-01

Full Text Available The thiadiazoyl and sulfonyl-benzene rings in the title compound, C20H23N3O3S3, are aligned to the same side of the molecule, forming a twisted `U' shape [dihedral angle = 77.6 (5°]. The benzyl-benzene ring is orientated in the opposite direction from the molecule but projects approximately along the same axis as the other rings [dihedral angle between benzene rings = 28.2 (5°] so that, overall, the molecule has a flattened shape. The hydroxy and amine groups are almost syn which enables the formation of intermolecular hydroxy-OH...N(thiadiazoyl and amine-H...O(sulfonyl hydrogen bonds leading to a supramolecular chain aligned along the a axis.

4-Anilino-3-nitrobenzonitrile

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Changhua Ge

2010-12-01

Full Text Available In the title compound, C13H9N3O2, the aromatic rings are twisted with respect to each other, making a dihedral angle of 49.41 (9°. The nitro group and the nitrile group are nearly in the plane of the benzonitrile ring, the largest deviation from the plane being 0.123 (1 Å. There is an intramolecular N—H...O hydrogen bond forming an S(6 ring. Weak intermolecular C—H...O hydrogen bonds link the molecules into a chain parallel to the c axis. Futhermore, slipped π–π interactions between symmetry-related phenyl rings [centroid–centroid distance 3.808 (1 Å, interplanar distance 3.544 (8 Å with an offset of 21.5°] stabilize the structure.

SXLS storage ring design

International Nuclear Information System (INIS)

Anon.

1991-01-01

X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

1,3-Dibenzyl-2-(2-chlorophenyl-4-methylimidazolidine

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Augusto Rivera

2012-12-01

Full Text Available In the title compound, C24H25ClN2, the methine, methylene and methyl C atoms of the methyl-substituted imidazolidine ring are disordered over two sets of sites with a refined occupancy ratio of 0.834 (4:0.166 (4. Each disordered ring assumes an envelope conformation with an N atom as the flap. The pendant benzyl rings are oriented equatorially with respect to the imidazolidine ring. The chlorophenyl ring is inclined to the mean plane of the four planar atoms of the major component of the imidazolidine ring by 76.27 (12°. The dihedral angles between the chlorophenyl ring and the two benzyl rings are 55.31 (9 and 57.50 (8°; the dihedral angle between these latter rings is 71.59 (9°. In the crystal, molecules are linked by C—H...Cl interactions and a number of weak C—H...π interactions, involving all three aromatic rings, forming a three-dimensional structure.

3-(2-Fluorophenylsulfinyl-2,5,7-trimethyl-1-benzofuran

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Hong Dae Choi

2013-06-01

Full Text Available In the title compound, C17H15FO2S, the benzofuran ring system, being essentially planar, with an r.m.s. deviation from the least-squares plane of 0.009 (2 Å, makes a dihedral angle of 79.02 (5° with the plane of the 2-fluorophenyl group. In the crystal, molecules are linked by pairs of weak C—H...O hydrogen bonds into centrosymmetric dimers.

(2E-3-[4-(Dimethylaminophenyl]-1-(4-fluorophenylprop-2-en-1-one

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Jerry P. Jasinski

2011-02-01

Full Text Available The mean planes of the two benzene rings in the title compound, C17H16FNO, are twisted slightly, making a dihedral angle of 7.8 (1°. The prop-2-en-1-one group is also twisted slightly with a C—C—C—O torsion angle of −11.6 (3°. In the crystal, weak intermolecular C—H...O interactions link pairs of molecules, forming centrosymmetric dimers.

4′-Methyl-1H-14′,19′-dioxa-4′-azaspiro[indole-3,5′-tetracyclo[18.4.0.02,6.08,13]tetracosane]-1′(24′,8′,10′,12′,20′,22′-hexaene-2,7′(3H-dione

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Sibi Narayanan

2012-12-01

Full Text Available In the title compound, C29H28N2O4, the indoline ring system is essentially planar, with a maximum deviation of 0.027 (2 Å; the carbonyl O atom lies 0.102 (1 Å out of the least-squares plane of the indole ring. The pyrrolidine ring adopts a C-envelope conformation, with a C atom displaced by 0.643 (2 Å from the mean plane formed by the remaining ring atoms. The pyrrolidine ring makes a dihedral angle of 86.1 (8° with the indoline ring system. In the crystal, N—H...O hydrogen bonds result in the formation of cyclic centrosymmetric dimers [R22(8]. C—H...π interactions also occur, leading to a chain along the b-axis direction. There is a rather weak π–π electron interaction between the pyrrazole and benzene rings, with a centroid–centroid distance of 3.765 (1 Å.

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.)

4-(4-Chlorophenyl-6-(methylsulfanylpyrimidin-2-amine

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Qi-Hua Zhao

2009-08-01

Full Text Available In the title compound, C11H10ClN3S, the dihedral angle between the benzene and pyrimidine rings is 3.99 (4°. In the crystal, intermolecular N—H...N hydrogen bonds link the molecules into ribbons of R22(8 rings parallel to [100]. Weak C—H...S contacts connect adjacent ribbons into a two-dimensional undulating layer-like structure extending parallel to (110. The benzene and pyrimidine rings of adjacent molecules have the offset face-to-face π–π stacking interactions in a zigzag fashion along the c axis, with perpendicular ring distances of 3.463 and 3.639 Å, and a dihedral angle between the planes of 3.99< (2°. The distance between the ring centroids is 4.420 (2 Å.

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.

3,3′-Bis(quinolin-8-yl-1,1′-[4,4′-methylenebis(4,1-phenylene]diurea

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Avijit Pramanik

2012-01-01

Full Text Available The title compound, C33H26N6O2, contains two 3-(quinolin-8-ylurea groups linked to a diphenylmethane. The asymmetric unit contains two molecules, A and B. Each quinoline plane is essentially parallel to the attached urea unit [dihedral angles = 8.97 (18 and 8.81 (19 in molecule A and 18.47 (18 and 4.09 (19° in molecule B]. The two benzene rings are twisted, making dihedral angles of 81.36 (8° in A and 87.20 (9° in B. The molecular structures are stabilized by intramolecular N—H...N hydrogen bonds. In the crystal, each urea O atom is involved in two N—H...O hydrogen bonds, generating two interpenetrating three-dimensional sets of molecules.

3,4-Dimethoxy-N-(3-nitrobenzylideneaniline

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Ali Asghar Jarrahpour

2008-11-01

Full Text Available The title compound, C15H14N2O4, has two crystallographically independent molecules in the asymmetric unit. In both molecules, the nitro and the two methoxy substituents are coplanar with the benzene rings to which they are attached. The benzene rings are nearly coplanar, with dihedral angles between the two benzene rings of 10.39 (8 and 5.95 (8° in the two molecules. The two independent molecules in the asymmetric unit are rotated with respect to each other such that the dihedral angles between equivalent benzene rings are 49.11 (8 and 63.93 (8°. In the crystal structure, intermolecular C—H...O hydrogen-bond contacts and a weak C—H...π interaction are observed.

(Z-3-(4-Chlorophenyl-1-(2,4-difluorophenyl-2-(1H-1,2,4-triazol-1-ylprop-2-en-1-one

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Xin-Mei Peng

2012-06-01

Full Text Available The asymmetric unit of the title compound, C17H10ClF2N3O, contains three independent molecules. In each molecule, the C=C bond has a cis conformation with respect to the triazole and chlorophenyl groups. The dihedral angles formed by the triazole ring with the diflurophenyl and chlorophenyl benzene rings, respectively, are 20.10 (14 and 73.22 (15, 25.31 (15 and 84.44 (15, and 16.44 (13 and 61.72 (14° in the three molecules while the dihedral angles between the benzene rings are 66.54 (13, 85.82 (12 and 58.37 (12°.

Ethyl 2-[1-(3-methylbutyl-4-phenyl-1H-1,2,3-triazol-5-yl]-2-oxoacetate

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Muhammad Hafeez

2013-12-01

Full Text Available In the title compound, C17H21N3O3, the non-planar (r.m.s. deviation = 0.212 Å ethyl (oxoacetate group is oriented towards the phenyl substituent. The triazole and benzene rings are twisted with respect to each other, making a dihedral angle of 41.69 (6°. In the crystal, molecules are arranged into centrosymmetric R22(10 dimers via pairs of C—H...O interactions involving the ethyl (oxoacetate groups. In addition, the triazole rings show π–π stacking interactions, with their centroids at a distance of 3.745 (2 Å.

N-(3-Chlorophenylmaleamic acid

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B. Thimme Gowda

2010-07-01

Full Text Available In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond within the maleamic acid unit and the second is a C—H...O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1° with the phenyl ring. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(7 chains running [010].

6-Butyl-5-(4-methoxyphenoxy-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidin-7(6H-one

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Hong-Mei Wang

2009-12-01

Full Text Available The asymmetric unit of the title compound, C21H21N5O3, consists of two geometrically similar molecules. The fused rings of the triazolo[4,5-d]pyrimidine system are nearly coplanar, making dihedral angels of 1.48 (18 and 1.34 (16°, and the phenyl rings are twisted by 12.3 (1 and 8.7 (1° with respect to the triazolopyrimidine plane. The ethyl groups of the n-butyl side chains are disordered over two sites in each of the independent molecules, the ratios of occupancies being 0.60:0.40 and 0.61:0.39.

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.

N′-[Bis(benzylsulfanylmethylidene]-4-methoxybenzohydrazide

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Jerry P. Jasinski

2010-08-01

Full Text Available In the title compound, C23H22N2O2S2, the dihedral angles between the 4-methoxy-substituted phenyl ring and the other two phenyl rings are 84.4 (4 and 77.7 (1°, respectively, while the dihedral angle between the two phenyl rings is 57.5 (2°. The amino group is not involved in an N—H hydrogen bond. The crystal packing is established by intermolecular C—H...O packing interactions involving a relatively rare weak three-center hydrogen bond between the keto O atom and H atoms of the two nearby phenyl rings, which link the molecules into chains running along the a axis. Additional weak intermolecular hydrogen-bond interactions between the 4-methoxy O atom and one of the phenyl rings and provide added stability to the crystal packing.

Analysis of reforming process of large distorted ring in final enlarging forging

International Nuclear Information System (INIS)

Miyazawa, Takeshi; Murai, Etsuo

2002-01-01

In the construction of reactors or pressure vessels for oil chemical plants and nuclear power stations, mono block open-die forging rings are often utilized. Generally, a large forged ring is manufactured by means of enlarging forging with reductions of the wall thickness. During the enlarging process the circular ring is often distorted and becomes an ellipse in shape. However the shape control of the ring is a complicated work. This phenomenon makes the matter still worse in forging of larger rings. In order to make precision forging of large rings, we have developed the forging method using a v-shape anvil. The v-shape anvil is geometrically adjusted to fit the distorted ring in the final circle and reform automatically the shape of the ring during enlarging forging. This paper has analyzed the reforming process of distorted ring by computer program based on F.E.M. and examined the effect on the precision of ring forging. (author)

tert-Butyl 6-bromo-1,4-dimethyl-9H-carbazole-9-carboxylate

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Jean-François Lohier

2010-08-01

Full Text Available The title compound, C19H20BrNO2, consists of a carbazole skeleton with methyl groups at positions 1 and 4, a protecting group located at the N atom and a Br atom at position 6. The pyrrole ring is oriented at dihedral angles of 1.27 (7 and 4.86 (7° with respect to the adjacent benzene rings. The dihedral angle between the benzene rings is 5.11 (7. The crystal structure is determined mainly by intramolecular C—H...O and intermolecular π–π interactions. π-stacking between adjacent molecules forms columns with a parallel arrangement of the carbazole ring systems. The presence of the tert-butoxycarbonyl group on the carbazole N atom and the intramolecular hydrogen bond induce a particular conformation of the exocyclic N—C bond within the molecule.

1,3,5-Tri-p-tolylpentane-1,5-diol

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A. Thiruvalluvar

2014-02-01

Full Text Available In the title compound, C26H30O2, the central benzene ring forms dihedral angles of 14.85 (15 and 28.17 (14° with the terminal benzene rings. The dihedral angle between the terminal benzene rings is 32.14 (13°. The crystal packing exhibits two strong intermolecular O—H...O hydrogen bonds, forming directed four-membered co-operative rings. A region of disordered electron density, most probably disordered ethyl acetate solvent molecules, occupying voids of ca 519 Å3 for an electron count of 59, was treated using the SQUEEZE routine in PLATON [Spek (2009. Acta Cryst. D65, 148–155]. Their formula mass and unit-cell characteristics were not taken into account during refinement. The structure was refined as an inversion twin [absolute structure parameter = −0.3 (4].

Storage Rings

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

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

Ethyl 2-(1,2,3,4-tetrahydrospiro[carbazole-3,2′-[1,3]dioxolan]-9-ylacetate

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Philipp M. G. Löffler

2009-04-01

Full Text Available In the title compound, C18H21NO4, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation. The dioxolane ring and ethylacetate substituent point to opposite sides of the carbazole plane. The ethylacetate substituent adopts an essentially fully extended conformation, and its mean plane forms a dihedral angle of 83.8 (1° with respect to the carbazole mean plane. The molecules are arranged into stacks in which the carbazole planes form a dihedral angle of 4.4 (1° and have an approximate interplanar separation of 3.6 Å.

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

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Qun Qian

2008-07-01

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

2-Methyl-3-(2-methylphenyl-4-oxo-3,4-dihydroquinazolin-8-yl 4-bromobenzene-1-sulfonate

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Edward R. T. Tiekink

2012-03-01

Full Text Available The title molecule, C22H17BrN2O4S, has a twisted U shape, the dihedral angle between the quinazolin-4-one and bromobenzene ring systems being 46.25 (8°. In order to avoid steric clashes with adjacent substituents on the quinazolin-4-one ring, the N-bound tolyl group occupies an orthogonal position [dihedral angle = 89.59 (8°]. In the crystal, molecules are connected into a three-dimensional architecture by C—H...O interactions, with the ketone O atom accepting two such bonds and a sulfonate O atom one.

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

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U. H. Patel

2013-06-01

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

2-{[2-Methyl-3-(2-methylphenyl-4-oxo-3,4-dihydroquinazolin-8-yl]oxy}acetonitrile

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Adel S. El-Azab

2012-07-01

Full Text Available In the title compound, C18H15N3O2, the fused ring system is almost planar [the dihedral angle between the six-membered rings is 1.81 (6°]. The 2-tolyl ring is approximately orthogonal to this plane [dihedral angle = 83.03 (7°] as is the acetonitrile group [C—O—C—C torsion angle = 79.24 (14°] which is also syn to the methyl substituent of the tolyl group. In the crystal, supramolecular layers are formed in the bc plane mediated by C—H...O, C—H...N and C—H...π interactions. The tolyl group is disordered over two positions in a 0.852 (3:0.148 (3 ratio.

Ethyl 5-cyano-4-[2-(2,4-dichlorophenoxyacetamido]-1-phenyl-1H-pyrrole-3-carboxylate

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Jing Xu

2009-08-01

Full Text Available In the title compound, C22H17Cl2N3O4, the pyrrole ring and the 2,4-dichlorophenyl group form a dihedral angle of 8.14 (13°; the phenyl ring is twisted with respect to the pyrrole ring, forming a dihedral angle of 60.77 (14°. The C=O bond length is 1.213 (3 Å, indicating that the molecule is in the keto form, associated with a –CONH– group, and the amide group adopts the usual trans conformation. The molecule is stabilized by an intramolecular N—H...O hydrogen-bonding interaction. In the crystal, the stacked molecules exhibit intermolecular C—H...O and C—H...N hydrogen-bonding interactions.

(E-1-(2-Bromophenyl-3-(2,5-dimethoxyphenylprop-2-en-1-one

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Jerry P. Jasinski

2010-08-01

Full Text Available The title compound, C17H15BrO3, is a chalcone with the 2-bromophenyl and 2,5-dimethoxyphenyl rings bonded at opposite ends of a propene group. The dihedral angle between the mean planes of the ortho-bromo and ortho,meta-dimethoxy-substituted benzene rings is 77.3 (1°. The dihedral angles between the mean plane of the prop-2-ene-1-one group and the mean planes of the 2-bromophenyl and 2,5-dimethoxyphenyl rings are 58.6 (1 and 30.7 (4°, respectively. Weak C—H...O, C—H...Br and π–π stacking intermolecular interactions [centroid–centroid distance = 3.650 (2 Å] are present in the structure.

(E-4-Amino-N′-(2-hydroxy-5-methylbenzylidenebenzohydrazide

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Hadi Kargar

2012-07-01

Full Text Available The asymmetric unit of the title compound, C15H15N3O2, comprises two crystallographically independent molecules (A and B, each having an E conformation around the C=N bond. In each molecule, there is an intramolecular O—H...N hydrogen bond making an S(6 ring motif. The dihedral angles between the substituted phenyl rings are 17.49 (9 and 10.03 (9°. In the crystal, N—H...O hydrogen bonds link neighbouring independent molecules into infinite chains, of the type –A–B–A–B–, along the a axis, enclosing R21(7 ring motifs. The chains are linked by N—H...O hydrogen bonds and C—H...O interactions, leading to the formation of a three-dimensional network.

Crystal structure of methyl (Z-2-[(Z-3-methyl-2-({(E-1-[(R*-4-methylcyclohex-3-en-1-yl]ethylidene}hydrazinylidene-4-oxothiazolidin-5-ylidene]acetate

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Mourad Fawzi

2017-11-01

Full Text Available The new title 4-thiazolidinone derivative, C16H21N3O3S, was obtained from the cyclization reaction of 4-methyl-3-thiosemicarbazone and dimethyl acetylenedicarboxylate (DMAD. The cyclohexylidene ring has an envelope conformation with the stereogenic centre C atom as the flap. Its mean plane makes a dihedral angle of 56.23 (9° with the thiazolidine ring mean plane. In the crystal, molecules are linked by C—H...O hydrogen bonds forming chains propagating in the [001] direction. Within the chains there are offset π–π interactions between the thiazolidine rings of inversion-related molecules [centroid–centroid distance = 3.703 (1 Å]. The chains are linked by further C—H...O hydrogen bonds, forming slabs parallel to the ac plane.

{2-[(4-Nitrobenzylideneamino]-4,5,6,7-tetrahydro-1-benzothiophen-3-yl}(phenylmethanone

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Manpreet Kaur

2014-06-01

Full Text Available In the title compound, C22H18N2O3S, disorder is found in the benzoyl group (A and B, as well as for four C atoms of the cyclohexene ring. Two orientations were modeled in a 0.583 (5:0.417 (5 ratio. The cyclohexene ring is in a distorted chair conformation. The dihedral angles between the mean plane of the thiophene ring and the 4-nitrobenzene and phenyl rings are 30.9 (8 and 64.8 (3 (A and 62.4 (7° (B. The mean planes of the 4-nitrobenzene and the phenyl rings are almost perpendicular to each other, with dihedral angles of 85.4 (1 (A and 83.9 (8° (B. An extensive array of weak C—H...O interactions consolidate molecules into a three-dimensional architecture, forming chains along [001] and [010] and layers parallel to (011.

Acceptability of the vaginal contraceptive ring among adolescent women.

Science.gov (United States)

Terrell, Lekeisha R; Tanner, Amanda E; Hensel, Devon J; Blythe, Margaret J; Fortenberry, J Dennis

2011-08-01

Although underutilized, the vaginal contraceptive ring has several advantages over other contraceptive methods that could benefit adolescents. We examined factors that may influence willingness to try the vaginal ring including: sexual and contraceptive history, genital comfort, and vaginal ring characteristics. Cross sectional Midwestern adolescent health clinics Adolescent women (N = 200; 14-18 years; 89% African-American) INTERVENTIONS/MAIN OUTCOME MEASURES: All participants received education about the vaginal ring and viewed pictures demonstrating insertion; they then completed a visual/audio computer-assisted self interview. The primary outcome variable, willingness to try the vaginal ring, was a single Likert-scale item. Over half the participants reported knowledge of the vaginal ring with healthcare providers identified as the most important source of contraceptive information. Comfort with one's genitals, insertion and removal, using alternative methods of insertion, and knowing positive method characteristics were significantly associated with willingness to try the vaginal ring. A decreased willingness to try the vaginal ring was related to concerns of the ring getting lost inside or falling out of the vagina. Willingness to try the ring was associated with positive feelings about genitals (e.g., comfort with appearance, hygiene, function). Thus, to increase willingness to try the vaginal ring among adolescents, providers should make it common practice to discuss basic female reproductive anatomy, raise awareness about female genital health and address concerns about their genitals. Providers can offer alternative insertion techniques (e.g., gloves) to make use more accessible. These strategies may increase vaginal ring use among adolescents. 2011 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Solutions of the Yang-Baxter equation: Descendants of the six-vertex model from the Drinfeld doubles of dihedral group algebras

International Nuclear Information System (INIS)

Finch, P.E.; Dancer, K.A.; Isaac, P.S.; Links, J.

2011-01-01

The representation theory of the Drinfeld doubles of dihedral groups is used to solve the Yang-Baxter equation. Use of the two-dimensional representations recovers the six-vertex model solution. Solutions in arbitrary dimensions, which are viewed as descendants of the six-vertex model case, are then obtained using tensor product graph methods which were originally formulated for quantum algebras. Connections with the Fateev-Zamolodchikov model are discussed.

(4-Nitrophenylmethyl 2,3-dihydro-1H-pyrrole-1-carboxylate: crystal structure and Hirshfeld analysis

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Julio Zukerman-Schpector

2018-03-01

Full Text Available In the title compound, C12H12N2O4, the dihydropyrrole ring is almost planar (r.m.s. deviation = 0.0049 Å and is nearly coplanar with the adjacent C2O2 residue [dihedral angle = 4.56 (9°], which links to the 4-nitrobenzene substituent [dihedral angle = 4.58 (8°]. The molecule is concave, with the outer rings lying to the same side of the central C2O2 residue and being inclined to each other [dihedral angle = 8.30 (7°]. In the crystal, supramolecular layers parallel to (10-5 are sustained by nitrobenzene-C—H...O(carbonyl and pyrrole-C—H...O(nitro interactions. The layers are connected into a three-dimensional architecture by π(pyrrole–π(nitrobenzene stacking [inter-centroid separation = 3.7414 (10 Å] and nitro-O...π(pyrrole interactions.

4-[2-(4-cyanophenyl)ethenyl]-N-methylpyridinium tetraphenylborate.

Science.gov (United States)

Jin, Dan; Zhang, De Chun

2005-11-01

In the title compound, C(15)H(13)N(2)(+).C(24)H(20)B(-), the pyridyl ring of the cation makes a dihedral angle of 1.6 degrees with the benzene ring. Each is rotated in the same direction with respect to the central -C-CH=CH-C- linkage, by 3.8 and 5.3 degrees, respectively. The anions have a slightly distorted tetrahedral geometry. Molecular packing analysis was carried out using the packing energy portioning scheme in the program OPEC. Around each anion in the crystal structure there are eight anions, which interact with the central anion through C-H...pi interactions. The cations are hydrogen bonded in a head-to-tail fashion, forming chains along [101].

2,4-Dichloro-N-o-tolylbenzamide

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Aamer Saeed

2009-07-01

Full Text Available In the title compound, C14H11Cl2NO, the central C—C(O—N—C amide unit makes dihedral angles of 68.71 (11 and 54.92 (12°, respectively, with the dichlorobenzene and tolyl rings. The two aromatic rings are inclined at 16.25 (17°. In the crystal, N—H...O hydrogen bonds link molecules into zigzag chains propagating in [001]. C—H...Cl contacts link these chains and additional C—H...O contacts generate stacks down b. Weak C—H...π and C—Cl...π interactions [Cl...centroid distance = 3.5422 (15 Å] may also stabilize the structure.

6-Bromo-2-(4-chlorophenyl-3-methyl-3H-imidazo[4,5-b]pyridine

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Selma Bourichi

2016-05-01

Full Text Available In the title compound, C13H9BrClN3, the imidazopyridine fused-ring system is almost planar, with r.m.s. deviation of 0.006 (19 Å, and makes a dihedral angle of 29.32 (8° with the mean plane of the 4-chlorophenyl group. In the crystal, C—H...N hydrogen bonds link the molecules into chains propagating in the [100] direction. Weak intermolecular π–π interactions between the five- and six-membered rings of the 3H-imidazo[4,5-b]pyridine moieties of neighbouring molecules [centroid–centroid distance = 3.8648 (12 Å] further consolidate the packing into layers parallel to the ab plane.

Crystal structure of 3-amino-2-propylquinazolin-4(3H-one

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Gamal A. El-Hiti

2015-08-01

Full Text Available In the title molecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H-one mean plane, making a dihedral angle of 88.98 (9°. In the crystal, molecules related by an inversion centre are paired via π–π overlap, indicated by the short distances of 3.616 (5 and 3.619 (5 Å between the centroids of the aromatic rings of neighbouring molecules. Intermolecular N—H...N and N—H...O hydrogen bonds form R66(30 rings and C(5 chains, respectively, generating a three-dimensional network. Weak C—H...O interactions are also observed.

4-Benzyl-6-bromo-2-phenyl-4H-imidazo[4,5-b]pyridine

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Y. Ouzidan

2010-04-01

Full Text Available The imidazopyridine fused ring in the title compound, C19H14BrN3, is almost coplanar with the phenyl ring at the 2-position of the five-membered ring [dihedral angle = 2.4 (1. The crystal structure features short Br...Br contacts [3.562 (1 Å].

The nonabelian tensor square of Bieberbach group of dimension five with dihedral point group of order eight

Science.gov (United States)

Fauzi, Wan Nor Farhana Wan Mohd; Idrus, Nor'ashiqin Mohd; Masri, Rohaidah; Sarmin, Nor Haniza

2014-07-01

The nonabelian tensor product was originated in homotopy theory as well as in algebraic K-theory. The nonabelian tensor square is a special case of the nonabelian tensor product where the product is defined if the two groups act on each other in a compatible way and their action are taken to be conjugation. In this paper, the computation of nonabelian tensor square of a Bieberbach group, which is a torsion free crystallographic group, of dimension five with dihedral point group of order eight is determined. Groups, Algorithms and Programming (GAP) software has been used to assist and verify the results.

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)

Ring-Resonator/Sol-Gel Interferometric Immunosensor

Science.gov (United States)

Bearman, Gregory; Cohen, David

2007-01-01

A proposed biosensing system would be based on a combination of (1) a sensing volume containing antibodies immobilized in a sol-gel matrix and (2) an optical interferometer having a ring resonator configuration. The antibodies would be specific to an antigen species that one seeks to detect. In the ring resonator of the proposed system, light would make multiple passes through the sensing volume, affording greater interaction length and, hence, greater antibody- detection sensitivity.

Crystal structures of salen-type ligands 2-[(1E-({1-(3-chlorophenyl-2-[(E-(2-hydroxybenzylideneamino]propyl}iminomethyl]phenol and 2-[(1E-({1-(4-chlorophenyl-2-[(E-(2-hydroxybenzylideneamino]propyl}iminomethyl]phenol

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A. Gayathri

2017-12-01

Full Text Available The title compounds, C23H21ClN2O2, differ from each other only by the position of the Cl atom on the corresponding benzene ring: meta relative to the central sp3 C atom for (I and para for (II. In (I, the hydroxyphenyl rings are almost parallel, the dihedral angle between the mean planes being 9.2 (2°, but in (II, the relative position of the ring is different, characterized by a dihedral angle of 48.5 (1°. Compound (I features intramolecular O—H...N and intermolecular C—H...O hydrogen bonds, while in (II, intramolecular O—H...N, C—H...N hydrogen bonds and weak intermolecular C—H...π interactions are observed. Compound (I was refined as an inversion twin.

Ethyl 2-(1,2,3,4-tetrahydro­spiro­[carba­zole-3,2′-[1,3]dioxolan]-9-yl)acetate

Science.gov (United States)

Löffler, Philipp M. G.; Ulven, Trond; Bond, Andrew D.

2009-01-01

In the title compound, C18H21NO4, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation. The dioxolane ring and ethyl­acetate substituent point to opposite sides of the carbazole plane. The ethyl­acetate substituent adopts an essentially fully extended conformation, and its mean plane forms a dihedral angle of 83.8 (1)° with respect to the carbazole mean plane. The mol­ecules are arranged into stacks in which the carbazole planes form a dihedral angle of 4.4 (1)° and have an approximate inter­planar separation of 3.6 Å. PMID:21582427

2-[(2-{Bis[2-(2-hydroxy-5-nitrobenzylideneaminoethyl]amino}ethyliminomethyl]-4-nitrophenol acetonitrile monosolvate

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Kwang Ha

2010-12-01

Full Text Available In the title compound, C27H27N7O9·CH3CN, the three nitro groups of the polydentate tripodal Schiff base are located approximately parallel to their respective carrier benzene rings, making dihedral angles of 3.9 (4, 5.0 (4 and 6.3 (4°. Intramolecular O—H...N hydrogen bonds between the hydroxy O atoms and the imine N atoms, with O...N distances in the range 2.607 (3–2.665 (3 Å, form nearly planar six-membered rings. In the crystal, weak intermolecular C—H...O and C—H...N hydrogen bonds occur and several intra- and intermolecular π–π interactions are present between adjacent benzene rings, with a shortest centroid–centroid distance of 3.507 (2 Å.

5-[(E-(2-Hydroxybenzylideneamino]-1H-1,3-benzimidazole-2(3H-thione

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Hoong-Kun Fun

2011-01-01

Full Text Available There are two molecules in the asymmetric unit of the title compound, C14H11N3OS. In each, the benzimidazole ring system is essentially planar, with maximum deviations of 0.010 (2 and 0.006 (2 Å, and makes dihedral angles of 8.70 (9 and 13.75 (8°, respectively, with the hydroxy-substituted benzene rings. Each molecule adopts an E configuration about the central C=N double bond. In the crystal, the two independent molecules are connected via intermolecular N—H...S hydrogen bonds, forming dimers. Furthermore, the dimers are connected by N—H...O hydrogen bonds into molecular ribbons along the c axis. There is an intramolecular O—H...N hydrogen bond in each molecule, which generates an S(6 ring motif.

1-Benzyl-3-[3-(naphthalen-2-yloxypropyl]imidazolium hexafluorophosphate

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Kun Huang

2011-08-01

Full Text Available In the title salt, C23H23N2O+·PF6−, the PF6− anion is highly disordered (occupancy ratios of 0.35:0.35:0.3, 0.7:0.15:0.15, 0.7:0.3 and 0.35:0.35:0.15:0.15 with the four F atoms in the equatorial plane rotating about the axial F—P—F bond. The mean plane of the imidazole ring makes dihedral angles of 82.44 (17 and 14.39 (16°, respectively, with the mean planes of the benzene ring and the naphthalene ring system. The crystal structure is stabilized by C—H...F hydrogen bonds. In addition, π–π [centroid–centroid distances = 3.7271 (19–3.8895 (17 Å] and C—H...π interactions are observed.

N-[5-Methyl-2-(2-nitrophenyl-4-oxo-1,3-thiazolidin-3-yl]pyridine-3-carboxamide monohydrate

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Mehmet Akkurt

2011-02-01

Full Text Available In the title compound, C16H14N4O4S·H2O, the benzene and pyridine rings make a dihedral angle of 85.8 (1°. Both enantiomers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C5 of the thiazolidine ring were therefore refined with common site-occupation factors of 0.531 (9 and 0.469 (9, respectively, for each stereoisomer. In the crystal, intermolecular N—H...O, O—H...O and O—H...N hydrogen bonds link the molecules, forming a three-dimensional supramolecular network. The crystal structure further shows π–π stacking interactions [centroid–centroid distance = 3.5063 (13 Å] between the pyridine rings.

N-[5-Methyl-2-(2-nitro-phen-yl)-4-oxo-1,3-thia-zolidin-3-yl]pyridine-3-carboxamide monohydrate.

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Akkurt, Mehmet; Celik, Ismail; Demir, Hale; Ozkırımlı, Sumru; Büyükgüngör, Orhan

2011-01-08

In the title compound, C(16)H(14)N(4)O(4)S·H(2)O, the benzene and pyridine rings make a dihedral angle of 85.8 (1)°. Both enanti-omers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C(5) of the thia-zolidine ring) were therefore refined with common site-occupation factors of 0.531 (9) and 0.469 (9), respectively, for each stereoisomer. In the crystal, inter-molecular N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds link the mol-ecules, forming a three-dimensional supra-molecular network. The crystal structure further shows π-π stacking inter-actions [centroid-centroid distance = 3.5063 (13) Å] between the pyridine rings.

3-(4-Fluorobenzoyl-4-(4-fluorophenyl-4-hydroxy-2,6-diphenylcyclohexane-1,1-dicarbonitrile

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B. Narayana

2014-06-01

Full Text Available In the title compound, C33H24F2N2O2, the cyclohexane ring adopts a slightly distorted chair conformation. The dihedral angle between the planes of the phenyl rings is 71.80 (9°, while the planes of the fluorophenyl and fluorobenzoyl rings are inclined to one another by 31.04 (10°. The dihedral angles between the planes of the phenyl ring adjacent to the 4-hydroxy group and those of the the fluorophenyl and fluorobenzoyl rings are 51.64 (10 and 34.31 (10°, respectively, while the corresponding angles for the phenyl ring adjacent to the 3-(4-fluorobenzoyl group are 57.51 (9 and 85.02 (10°, respectively. An intramolecular O—H...O hydrogen bond generates an S(6 ring motif. In the crystal, molecules are linked via pairs of O—H...N hydrogen bonds, forming inversion dimers. The dimers are linked via C—H...N and C—H...O hydrogen bonds, forming chains along the c-axis direction. C—H...F hydrogen bonds link the chains into sheets lying parallel to the bc plane.

Ion-ion collisions and ion storage rings

International Nuclear Information System (INIS)

Mowat, J.R.

1988-01-01

Improved understanding of fundamental ion-ion interactions is expected to emerge from research carried out with ion storage rings. In this short survey the significant advantages and unique features that make stored ions useful targets for collision experiments are reviewed and discussed. It is pointed out that improvements to existing ion-ion experiments, as well as qualitatively new experiments, should occur over the next few years as ion storage rings become available for atomic physics. Some new experiments are suggested which are difficult if not impossible with present-day technology, but which seem feasible at storage rings facilities. (orig.)

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

Crystal structure of 4-fluoro-N-[2-(4-fluoro-benzo-yl)hydra-zine-1-carbono-thio-yl]benzamide.

Science.gov (United States)

Firdausiah, Syadza; Salleh Huddin, Ameera Aqeela; Hasbullah, Siti Aishah; Yamin, Bohari M; Yusoff, Siti Fairus M

2014-09-01

In the title compound, C15H11F2N3O2S, the dihedral angle between the fluoro-benzene rings is 88.43 (10)° and that between the central semithiocarbazide grouping is 47.00 (11)°. The dihedral angle between the amide group and attached fluoro-benzene ring is 50.52 (11)°; the equivalent angle between the carbonyl-thio-amide group and its attached ring is 12.98 (10)°. The major twists in the mol-ecule occur about the C-N-N-C bonds [torsion angle = -138.7 (2)°] and the Car-Car-C-N (ar = aromatic) bonds [-132.0 (2)°]. An intra-molecular N-H⋯O hydrogen bond occurs, which generates an S(6) ring. In the crystal, the mol-ecules are linked by N-H⋯O and N-H⋯S hydrogen bonds, generating (001) sheets. Weak C-H⋯O and C-H⋯F inter-actions are also observed.

4-(9-Anthryl-1-(2-methoxyphenylspiro[azetidin-3,9′-xanthen]-2-one

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2009-03-01

Full Text Available The stabilized conformation of the title compound, C36H25NO3, 4-(9-anthryl-1-(2-methoxyphenyl-spiro[azetidin-3,9′-xanthen]-2-one, may be compared with that of the isomeric compound 4-(9-anthryl-1-(4-methoxyphenylspiro[azetidin-3,9′-xanthen]-2-one. In the title isomer, the methoxy group is slightly twisted out of the plane of the attached benzene ring, with a C—O—C—C torsion angle of 31.5 (2°. Its β-lactam ring is essentially planar, with a maximum deviation of −0.021 (1 Å. The β-lactam ring makes dihedral angles of 18.815 (9, 83.33 (7 and 53.62 (8° with the mean planes of the benzene, xanthene and anthracene ring systems, respectively. The structure is stabilized by C—H...π, C—H...N and C—H...O interactions.

TREE SELECTING AND TREE RING MEASURING IN DENDROCHRONOLOGICAL INVESTIGATIONS

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Sefa Akbulut

2004-04-01

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

3-[4-(Dimethylaminophenyl]-1-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-ylprop-2-en-1-one

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Moha Berraho

2011-01-01

Full Text Available The title compound, C23H31NO, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation. The dihedral angle between the latter ring and its substituent is 83.6 (7°.

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

3-(4-Fluorophenylsulfinyl-5-iodo-2-methyl-1-benzofuran

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Hong Dae Choi

2010-07-01

Full Text Available In the title compound, C15H10FIO2S, the O atom and the 4-fluorophenyl group of the 4-fluorophenylsulfinyl substituent are located on opposite sides of the plane through the benzofuran fragment; the 4-fluorophenyl ring is nearly perpendicular to this plane, making a dihedral angle of 83.37 (7°. The crystal structure is stabilized by weak intermolecular C—H...O hydrogen bonds and an I...O interaction [I...O = 3.255 (2 Å]. The crystal structure also exhibits intermolecular C—F...π interactions [3.068 (2 Å], and aromatic π–π interactions between the furan and benzene rings of neighbouring benzofuran fragments [centroid–centroid distance = 3.636 (2 Å].

1-Decyl-6-nitro-1H-benzimidazol-2(3H-one

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Younes Ouzidan

2011-11-01

Full Text Available The title molecule, C17H25N3O3, is built up from fused six- and five-membered rings linked to a –C10H21 chain. The fused-ring system is essentially planar, the largest deviation from the mean plane being 0.009 (2 Å. The chain is roughly perpendicular to this plane, making a dihedral angle of 79.5 (2°. In the crystal, N—H...O hydrogen bonds build infinite chains along [010]. There are channels in the structure containing disordered hexane. The contribution of this solvent to the scattering power was suppressed using the SQUEEZE option in PLATON [Spek (2009. Acta Cryst. D65, 148–155].

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

Latest on polarization in electron storage rings

International Nuclear Information System (INIS)

Chao, A.W.

1983-01-01

The field of beam polarization in electron storage rings is making rapid progress in recent several years. This report is an attempt to summarize some of these developments concerning how to produce and maintain a high level of beam polarization. Emphasized will be the ideas and current thoughts people have on what should and could be done on electron rings being designed at present such as HERA, LEP and TRISTAN. 23 references

(E-2-(4-Chlorophenoxy-N′-(pyridin-4-ylmethylideneacetohydrazide

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Xiao-jin Rao

2013-01-01

Full Text Available In the title compound, C14H12ClN3O2, the acylhydrazone base [C(=O—N—N=C] is essentially planar, with an r.m.s. deviation of 0.0095 Å, and makes a dihedral angle of 12.52 (10°with the pyridine ring. In the crystal, molecules are linked via pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8 graph-set motif. The dimers are linked via C—H...π interactions forming chains along [101].

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.

Crystal structure of methyl 2-(2H-1,3-benzodioxol-5-yl-7,9-dibromo-8-oxo-1-oxaspiro[4.5]deca-2,6,9-triene-3-carboxylate

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Lucimara Julio Martins

2014-12-01

Full Text Available The title compound, C18H12Br2O6, was synthesized from Morita–Baylis–Hillman adducts. It incorporates the brominated spiro-hexadienone moiety typically exhibited by compounds of this class that exhibit biological activity. Both the brominated cyclohexadienone and the central five-membered rings are nearly planar (r.m.s. deviations of 0.044 and 0.016 Å, respectively, being almost perpendicularly oriented [interplanar angle = 89.47 (5°]. With respect to the central five-membered ring, the brominated cyclohexadienone ring, the benzodioxol ring and the carboxylate fragment make C—O—C—C, O—C—C—C and C—C—C—O dihedral angles of −122.11 (8, −27.20 (11 and −8.40 (12°, respectively. An intramolecular C—H...O hydrogen bond occurs. In the crystal, molecules are linked by non-classical C—H...O and C—H...Br hydrogen bonds resulting in a molecular packing in which the brominated rings are in a head-to-head orientation, forming well marked planes parallel to the b axis.

3-Ethyl-4-[(E-(4-fluorobenzylideneamino]-1H-1,2,4-triazole-5(4H-thione

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Alphonsus D'souza

2012-05-01

Full Text Available In the title compound, C11H11FN4S, the dihedral angle between the 1,2,4-triazole ring and the benzene ring is 25.04 (12° and an intramoleuclar C—H...S interaction leads to an S(6 ring. In the crystal, inversion dimers linked by pairs of N—H...S hydrogen bonds generate R22(8 loops.

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.

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

Science.gov (United States)

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

2018-02-01

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

Ethyl 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate

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De-Cai Wang

2008-11-01

Full Text Available In the title compound, C16H15F2NO4, the dihedral angle between the three-membered ring and the quinoline ring system is 64.3 (3°. In the crystal structure, intermolecular C—H...O hydrogen bonds link the molecules, forming a column running along [101].

(E,E-6,6′-Dimethoxy-2,2′-[o-phenylenebis(nitrilomethylidyne]diphenol

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Yong Wang

2009-04-01

Full Text Available In the title compound, C22H20N2O4, the central benzene ring forms dihedral angles of 3.2 (2 and 61.1 (1° with the two outer substituted benzene rings. Intramolecular O—H...N hydrogen bonds are formed by both hydroxyl groups.

5,11-Ditosyl-5H,11H-dibenzo[b,f][1,5]diazocine-6,12-dione acetic acid hemisolvate

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Najat Abbassi

2013-04-01

Full Text Available The molecular structure of the title compound, C28H22N2O6S2·0.5CH3COOH, is built up from three fused rings, two six and one eight membered. The eight-membered ring shows a boat conformation and the dihedral angle between the two benzene groups attached thereto is 66.43 (11°, resulting in a V-shaped geometry. Two tosyl substituents are bound to the N atoms. The planes through the tolyl rings are roughly perpendicular, as indicated by the dihedral angle of 82.44 (12°. In the crystal, the molecule and its inversion-related symmetry-equivalent are linked to the acetic acid solvent molecule by non-classical O—H...O and C—H...O hydrogen bonds. Two half-occupied acetic acid solvent molecules are disordered at the same site and linked by a center of symmetry.

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.

Injection, compression and stability of intense ion-rings

International Nuclear Information System (INIS)

Sudan, R.N.

1975-01-01

Recent advances in pulsed high power ion beam technology make possible the creation of intense ion-rings with strong self-magnetic fields by single pulse injection. Such ion rings have several uses in controlled fusion e.g., to produce a min parallel B parallel magnetic geometry with a mirror ratio much higher than is possible with external conductors. For even stronger ion rings a min parallel B parallel with closed lines of force (ASTRON type) can be created. For this purpose, since the ion energies required are much higher than are available from high power sources, magnetic compression can be utilized to increase the ion energy. The success of this scheme depends critically on the stability of the ion ring. The low frequency perturbations of the ring-plasma system is examined by means of a generalization of the energy principle which established sufficient conditions for stability. The high-frequency micro-instabilities and their nonlinear consequences are discussed in terms of conventional techniques

Vortex formation in narrow ferromagnetic rings

International Nuclear Information System (INIS)

Klaeui, M; Vaz, C A F; Lopez-Diaz, L; Bland, J A C

2003-01-01

The high-symmetry ring geometry is shown to exhibit a wide range of intriguing magnetostatic and magnetodynamic properties, which we survey in this topical review. We consider first the patterning and deposition techniques, which are used to fabricate ring structures (diameters between 0.1 and 2 μm) and discuss their respective advantages and disadvantages. The results of direct nanoscale imaging of the novel magnetization configurations present in rings with different geometrical parameters (including discs) are discussed. These results give valuable insight into the influence of the magnetic anisotropies governing the magnetic states. The different types of domain walls that arise are compared quantitatively to micromagnetic simulations. The magnetodynamic switching between the different magnetic states is described in detail. In particular we elaborate on the different geometry-dependent magnetic switchings, since the different transitions occurring allow us to determine which energy terms govern the reversal process. We discuss a process by which fast (sub-ns) and controlled switching can be achieved, therefore making rings an attractive geometry for applications, in addition to studying fundamental issues of nanomagnetism. (topical review)

5′-Methylsulfanyl-4′-oxo-7′-phenyl-3′,4′-dihydro-1′H-spiro[cyclohexane-1,2′-quinazoline]-8′-carbonitrile dimethylformamide monosolvate

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Xuan Liu

2011-08-01

Full Text Available In the title compound, C21H21N3OS·C3H7NO, the carbonitrile molecule is built up of two fused six-membered rings and one six-membered ring linked through a spiro C atom. The 1,3-diaza ring adopts an envelope conformation and the cyclohexane ring adopts a chair conformation. The dihedral angle between the aromatic rings is 46.7 (3°. In the crystal, the components are linked by N—H...O hydrogen bonds.

3,4-Dimethoxy-N-(4-nitrobenzylideneaniline

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Aliasghar Jarrahpour

2008-11-01

Full Text Available In the title molecule, C15H14N2O4, the dihedral angle between the two benzene rings is 29.52 (8°. The nitro and two methoxy substituents are almost coplanar with their respective benzene rings. The crystal structure is stabilized by intermolecular C—H...O interactions.

5-(5-Bromo-2-methoxyphenyl-2-fluoropyridine

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Muhammad Adeel

2012-09-01

Full Text Available In the title compound, C12H9BrFNO, the dihedral angle between the aromatic rings is 51.39 (5°; the C atom of the methoxy group is close to being coplanar with its attached ring (r.m.s. deviation = 0.0172 Å] and is oriented away from the pyridine ring. In the crystal, molecules interact by van der Waals forces.

Crystal structure of 4-fluoro-N-[2-(4-fluoro­benzo­yl)hydra­zine-1-carbono­thio­yl]benzamide

Science.gov (United States)

Firdausiah, Syadza; Salleh Huddin, Ameera Aqeela; Hasbullah, Siti Aishah; Yamin, Bohari M.; Yusoff, Siti Fairus M.

2014-01-01

In the title compound, C15H11F2N3O2S, the dihedral angle between the fluoro­benzene rings is 88.43 (10)° and that between the central semithiocarbazide grouping is 47.00 (11)°. The dihedral angle between the amide group and attached fluoro­benzene ring is 50.52 (11)°; the equivalent angle between the carbonyl­thio­amide group and its attached ring is 12.98 (10)°. The major twists in the mol­ecule occur about the C—N—N—C bonds [torsion angle = −138.7 (2)°] and the Car—Car—C—N (ar = aromatic) bonds [−132.0 (2)°]. An intra­molecular N—H⋯O hydrogen bond occurs, which generates an S(6) ring. In the crystal, the mol­ecules are linked by N—H⋯O and N—H⋯S hydrogen bonds, generating (001) sheets. Weak C—H⋯O and C—H⋯F inter­actions are also observed. PMID:25309250

ASSOCIATIVE RINGS SOLVED AS LIE RINGS

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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

Tuning cofactor redox potentials: the 2-methoxy dihedral angle generates a redox potential difference of >160 mV between the primary (Q(A)) and secondary (Q(B)) quinones of the bacterial photosynthetic reaction center.

Science.gov (United States)

Taguchi, Alexander T; Mattis, Aidas J; O'Malley, Patrick J; Dikanov, Sergei A; Wraight, Colin A

2013-10-15

Only quinones with a 2-methoxy group can act simultaneously as the primary (QA) and secondary (QB) electron acceptors in photosynthetic reaction centers from Rhodobacter sphaeroides. (13)C hyperfine sublevel correlation measurements of the 2-methoxy in the semiquinone states, SQA and SQB, were compared with quantum mechanics calculations of the (13)C couplings as a function of the dihedral angle. X-ray structures support dihedral angle assignments corresponding to a redox potential gap (ΔEm) between QA and QB of ~180 mV. This is consistent with the failure of a ubiquinone analogue lacking the 2-methoxy to function as QB in mutant reaction centers with a ΔEm of ≈160-195 mV.

Experimental Investigation of Piston Rings for Internal Combustion Engines

DEFF Research Database (Denmark)

Christiansen, Jens; Klit, Peder; Vølund, Anders

2007-01-01

One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. 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...... forces are small compared to the rest of the acting forces the main design idea is to fix the piston, while the cylinder liner moves. This approach makes it simple to measure the parameters mentioned above by putting the instrumentation in the piston. The aim of this paper is describe the tribological...

N-(2-Chlorophenyl-2-({5-[4-(methylsulfanylbenzyl]-4-phenyl-4H-1,2,4-triazol-3-yl}sulfanylacetamide

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Hoong-Kun Fun

2011-08-01

Full Text Available In the title molecule, C24H21ClN4OS2, the central 1,2,4-triazole ring forms dihedral angles of 89.05 (9, 86.66 (9 and 82.70 (10° with the chloro-substituted benzene ring, the methylsulfanyl-substituted benzene ring and the phenyl ring, respectively. In the crystal, molecules are linked into sheets parallel to (100 by intermolecular N—H...N and weak C—H...O hydrogen bonds.

3-Amino-N′-(2-oxoindolin-3-ylidenebenzohydrazide

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Rifat Ara Jamal

2011-08-01

Full Text Available The title compound, C15H12N4O2, contains two substituted benzohydrazide and indole rings linked via a C=N double bond. The dihedral angle between the benzene ring and the indole ring system is 11.38 (10°. The molecular structure is stabilized by an intramolecular N—H...O hydrogen bond, forming a six-membered ring. The crystal structure is consolidated by intermolecular N—H...O and C—H...O interactions, which result in sheets.

4-(2,4-Dichlorophenyl-2-(1H-indol-3-yl-6-methoxypyridine-3,5-dicarbonitrile

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M. N. Ponnuswamy

2008-10-01

Full Text Available In the title compound, C22H12Cl2N4O, the indole ring system and the benzene ring form dihedral angles of 21.18 (7° and 68.43 (8°, respectively, with the pyridine ring. The methoxy group is coplanar with the pyridine ring. In the crystal structure N—H...N intermolecular hydrogen bonds link the molecules into C(10 chains running along [011]. Intramolecular C—H...N hydrogen bonds are also observed.

4-Methoxy-3-nitrobiphenyl

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Xuqiang Chao

2012-01-01

Full Text Available In the title compound, C13H11NO3, the dihedral angle between the two benzene rings is 36.69 (2° and the nitro and methyoxy groups are oriented at 29.12 (14 and 2.14 (12° with respect to the benzene ring to which they are bonded.

4,5-Bis(4-methoxyphenoxyphthalonitrile

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Tianyou Peng

2010-10-01

Full Text Available The title compound, C22H16N2O4, was obtained unintentionally as the product of an attempted synthesis of a new phthalocyanine. The dihedral angles formed by the central benzene ring with the aromatic rings of the methoxyphenoxy groups are 85.39 (5 and 64.19 (5°.

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.

5,11-Ditosyl-5H,11H-dibenzo[b,f][1,5]diazo­cine-6,12-dione acetic acid hemisolvate

Science.gov (United States)

Abbassi, Najat; Bassou, Oulemda; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-01-01

The mol­ecular structure of the title compound, C28H22N2O6S2·0.5CH3COOH, is built up from three fused rings, two six and one eight membered. The eight-membered ring shows a boat conformation and the dihedral angle between the two benzene groups attached thereto is 66.43 (11)°, resulting in a V-shaped geometry. Two tosyl substituents are bound to the N atoms. The planes through the tolyl rings are roughly perpendicular, as indicated by the dihedral angle of 82.44 (12)°. In the crystal, the mol­ecule and its inversion-related symmetry-equivalent are linked to the acetic acid solvent mol­ecule by non-classical O—H⋯O and C—H⋯O hydrogen bonds. Two half-occupied acetic acid solvent mol­ecules are disordered at the same site and linked by a center of symmetry. PMID:23634138

5,11-Ditosyl-5H,11H-dibenzo[b,f][1,5]diazo-cine-6,12-dione acetic acid hemisolvate.

Science.gov (United States)

Abbassi, Najat; Bassou, Oulemda; Rakib, El Mostapha; Saadi, Mohamed; El Ammari, Lahcen

2013-04-01

The mol-ecular structure of the title compound, C28H22N2O6S2·0.5CH3COOH, is built up from three fused rings, two six and one eight membered. The eight-membered ring shows a boat conformation and the dihedral angle between the two benzene groups attached thereto is 66.43 (11)°, resulting in a V-shaped geometry. Two tosyl substituents are bound to the N atoms. The planes through the tolyl rings are roughly perpendicular, as indicated by the dihedral angle of 82.44 (12)°. In the crystal, the mol-ecule and its inversion-related symmetry-equivalent are linked to the acetic acid solvent mol-ecule by non-classical O-H⋯O and C-H⋯O hydrogen bonds. Two half-occupied acetic acid solvent mol-ecules are disordered at the same site and linked by a center of symmetry.

Crystal structures of Schiff base derivatives of 1-(3,4,5-trimethoxybenzylidene)thiosemicarbazide and (E)-N′-(3-nitrobenzylidene)isonicotinohydrazide

Energy Technology Data Exchange (ETDEWEB)

Dileep, C. S., E-mail: dileep.mmp.phy@gmail.com; Sridhar, M. A. [Department of Studies in Physics, Manasagangotri, University of Mysore, Mysore-570006 (India); Mallesh, L. [Department of Chemistry, JSS College of Arts, Commerce and Science, Ooty Road, Mysore-570025 (India)

2014-04-24

The crystal structures of 1-(3,4,5-trimethoxybenzylidene)thiosemicarbazide (1) and N′-(3-nitrobenzylidene) isonicotinohydrazide (2) have been determined by single-crystal X-ray diffraction. In compound 1, the position of C8, O1, O2, O3 atoms are in a distorted trigonal planar geometry. The mean plane of 3,4,5-trimethoxybenzylidene ring forms a dihedral angle of 5.39(14)° with the mean plane of thiosemicarbazide group. In the structure, the molecular packing is stabilized by intermolecular N–H with diaresisN, O–H with diaresisS and intramolecular C–H with diaresisO hydrogen bonds. In compound 2, the position of C8 atom and N1 atom are in a distorted trigonal planar geometry. The mean plane of phenyl ring forms a dihedral angle of 8.09° with that of the pyridine ring. In the structure, the molecular packing is stabilized by intermolecular N–H with diaresisN and intramolecular C–H with diaresisO hydrogen bonds.

2-(4-Hydroxyphenyl-1H-benzimidazol-3-ium chloride monohydrate

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Jazmin E. González-Padilla

2013-09-01

Full Text Available The title molecular salt, C13H11N2O+·Cl−·H2O, crystallizes as a monohydrate. In the cation, the phenol and benzimidazole rings are almost coplanar, making a dihedral angle of 3.18 (4°. The chloride anion and benzimidazole cation are linked by two N+—H...Cl− hydrogen bonds, forming chains propagating along [010]. These chains are linked through O—H...Cl hydrogen bonds involving the water molecule and the chloride anion, which form a diamond core, giving rise to the formation of two-dimensional networks lying parallel to (10-2. Two π–π interactions involving the imidazolium ring with the benzene and phenol rings [centroid–centroid distances = 3.859 (3 and 3.602 (3 Å, respectively], contribute to this second dimension. A strong O—H...O hydrogen bond involving the water molecule and the phenol substituent on the benzimidazole unit links the networks, forming a three-dimensional structure.

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].

meso-4,4′-Dimethoxy-2,2′-{[(3aR,7aS-2,3,3a,4,5,6,7,7a-octahydro-1H-benzimidazole-1,3-diyl]bis(methylene}diphenol

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Augusto Rivera

2013-07-01

Full Text Available The title compound, C23H30N2O4, a di-Mannich base derived from 4-methoxyphenol and cis-1,2-diaminecyclohexane, has a perhydrobenzimidazolidine nucleus, in which the cyclohexane ring adopts a chair conformation and the heterocyclic ring has a half-chair conformation with a C—N—C—C torsion angles of −48.14 (15 and −14.57 (16°. The mean plane of the heterocycle makes dihedral angles of 86.29 (6 and 78.92 (6° with the pendant benzene rings. The molecular structure of the title compound shows the presence of two interactions between the N atoms of the imidazolidine ring and the hydroxyl groups through intramolecular O—H...N hydrogen bonds with graph-set motif S(6. The unobserved lone pairs of the N atoms are presumed to be disposed in a syn conformation, being only the second example of an exception to the typical `rabbit-ears' effect in 1,2-diamines.

2-Chloro-N-(4-sulfamoylphenylacetamide

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Mehmet Akkurt

2010-07-01

Full Text Available In the title compound, C8H9ClN2O3S, the benzene ring makes a dihedral angle of 4.1 (9° with the amido –NHCO– plane including the major occupancy component of the carbonyl O atom [19 (4° for the minor component]. An intramolecular C—H...O interaction occurs. The O atom of the carbonyl group is disordered over two positions with site-occupancy factors of 0.67 (11 and 0.33 (11. Intermolecular N—H...O hydrogen bonds help to stabilize the crystal structure.

N-(2-Methylphenyl-1,2-benzoselenazol-3(2H-one

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Xu Zhu

2013-10-01

Full Text Available In the title Ebselen [systematic name: (2-phenyl-1,2-benzoisoselenazol-3-(2H-one] analogue, C14H11NOSe, the benzisoselenazolyl moiety (r.m.s. deviation = 0.0209 Å is nearly perpendicular to the N-arenyl ring, making a dihedral angle of 78.15 (11°. In the crystal, molecules are linked by C—H...O and Se...O interactions into chains along the c-axis direction. The Se...O distance [2.733 (3 Å] is longer than that in Ebselen (2.571 (3 Å].

Ethyl 4,6-O-benzylidene-2-deoxy-N-phthalimido-1-thio-β-d-glucopyranoside

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Göran Widmalm

2010-12-01

Full Text Available In the title compound, C23H23NO6S, the plane of the N-phthalimido group makes a dihedral angle of 67.4 (1° with the least square plane of the sugar ring defined by the C2, C3, C5 and O5 atoms using standard glucose nomenclature. The thioethyl group has the exo-anomeric conformation. In the crystal, intermolecular hydrogen bonds involving the hydroxy groups and the carbonyl O atoms of adjacent N-phthalimido groups form chains parallel to the b axis. The chains are further stabilized by C—H...π interactions.

Crystal structure of 4-(4-chlorophenyl-6-(morpholin-4-ylpyridazin-3(2H-one

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Abdullah Aydın

2015-08-01

Full Text Available In the title compound, C14H14ClN3O2, the morpholine ring adopts a chair conformation, with the exocyclic N—C bond in an equatorial orientation. The 1,6-dihydropyridazine ring is essentially planar, with a maximum deviation of 0.014 (1 Å, and forms a dihedral angle of 40.16 (7° with the plane of the benzene ring. In the crystal, pairs of centrosymmetrically related molecules are linked into dimers via N—H...O hydrogen bonds, forming R22(8 ring motifs. The dimers are connected via C—H...O and C—H...Cl hydrogen bonds, forming a three-dimensional network. Aromatic π–π stacking interactions [centroid–centroid distance = 3.6665 (9 Å] are also observed. Semi-empirical molecular orbital calculations were carried out using the AM1 method. The calculated dihedral angles between the pyridizine and benzene rings and between the pyridizine and morpholine (all atoms rings are 34.49 and 76.96°, respectively·The corresponding values obtained from the X-ray structure determination are 40.16 (7 and 12.97 (9°, respectively. The morpholine ring of the title compound in the calculated gas-phase seems to have a quite different orientation compared to that indicated by the X-ray structure determination.

Evaluation of radiation-induced degradation of silicon '0' ring

International Nuclear Information System (INIS)

Ikeshima, Yoshiaki; Shiraishi; Tadao; Sato, Ryuichi; Tanaka, Isao; Ichihashi, Yoshinori; Ito, Masayuki.

1990-12-01

Currently there is too few available data on mechanical properties of an 'O' ring made of organic material, which is used over an extensive period of time under actual Nuclear Reactor environmental conditions. The 'O' rings which were evaluated were made of Silicon Rubber, and are used to provide water tightness. The 'O' rings also served as a pressure boundary within the nozzle of the in-reactor tube in the Water Loop-2 (OWL-2) at the JMTR in Oarai, Ibaraki. The 'O' rings were subjected to a constant penetrating radiation (up to 3.46 kGy) over a period of thirteen (13) years. The effects on the mechanical properties of a Silicon Rubber 'O' Ring were evaluated after having been used over an extensive period of time in an actual in-reactor tube within a radiation environment; a full thirteen years in durations. In making comparison of the properties of other Silicon Rubber 'O' Rings. It was also found that these other 'O' rings were subject to Gamma Rays for a shorter period, but with the same amount of radiation as the 'O' rings in the reactor were supposedly to have received. The evaluation showed that a Silicon Rubber 'O' Ring could have been used for a period, as much as forty (40) years even with a (absorbed) dose of about 300 kGy, before the life expectancy of such an 'O' ring is fully met. It was also discovered that the mechanical properties of an Ethylene Propylene 'O' Rings (currently used in the new OWL-2 in-reactor tube) were much superior to those of the Silicon Rubber 'O' Rings. The Ethylene Propylene 'O' Rings had a live expectancy which was about three times that of a Silicon Rubber 'O' Rings. (author)

Proceedings of the SLAC/KEK linear collider workshop on damping ring

International Nuclear Information System (INIS)

Urakawa, J.; Yoshioka, M.

1992-07-01

Since the SLAC/KEK joint meeting was first held at SLAC in March 1987, we have had such a meeting annually with the present one the 6th. This meeting is planned to discuss the damping ring issue in particular. We have ever stressed the importance of study of damping rings and considered construction of a test damping ring as key issue for the ATF project, since we started construction of the ATF in 1987. In 1991 we had large-scale reconstruction of a building to make a shielded area where a 1.54 GeV injector linac for the ring is to be installed. (J.P.N.)

2-(1H-Imidazol-1-yl)-3-isopropyl-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

OpenAIRE

Xu, Sheng-Zhen

2007-01-01

In the title compound, C16H14N4OS, the three fused rings of the benzothieno[3,2-d]pyrimidinone unit are essentially coplanar, the maximum deviation from the mean plane being 0.067 (3) Å. The dihedral angle between the mean plane of the fused rings and the imidazole ring is 72.00 (3)°. Offset π–π stacking interactions involving the fused rings are effective in the stabilization of the crystal structure. The centroid–centroid distances between t...

(4bS,8aS-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl benzoate

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Radouane Oubabi

2014-08-01

Full Text Available The title compound, C27H34O2, was hemisynthesized through direct benzoylation of the naturally occurring meroterpene totarol. The central fused six-membered ring has a half-chair conformation, whereas the terminal six-membered ring displays a chair conformation. The dihedral angle between the fused benzene ring and the benzoyl benzene ring is 73.05 (14°. The S,S chirality of the molecule is consistent with the synthetic pathway, and confirmed by the refinement of the Flack parameter.

1,3-Di-4-pyridylpropane–4,4′-oxydibenzoic acid (1/1

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Hirofumi Hinode

2008-12-01

Full Text Available The hydrothermal reaction of Cd(NO32·4H2O, 1,3-di-4-pyridylpropane (BPP and 4,4′-oxydibenzoic acid (OBA led to the formation of the title compound, C13H14N2·C14H10O5. The asymmetric unit consists of one molecule of OBA and one of BPP. In the OBA molecule, one COOH group is nearly planar with its attached benzene ring [dihedral angle = 0.9 (1°], while the other COOH group is slightly twisted with a dihedral angle of 10.8 (3°. The carboxyl groups form strong intermolecular O—H...N hydrogen bonds with N atoms of the pyridine rings in BPP, linking the molecules into zigzag chains.

N′-(3-Bromo-4-methoxybenzylidenenicotinohydrazide monohydrate

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Feng-Yu Bao

2009-09-01

Full Text Available In the title compound, C14H12BrN3O2·H2O, the benzene ring is oriented at a dihedral angle of 39.66 (11° with respect to the pyridine ring. The solvent water molecule links with the organic compound via O—H...O, O—H...N and N—H...O hydrogen bonding.

2-Benzyl-6-chloro-1-(4-methylphenyl-1H-indole-3-carbonitrile

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Qiao Yan

2011-12-01

Full Text Available In the title compound, C23H17ClN2, the dihedral angle between the indole ring and the attached tolyl ring is 86.97 (8°. Weak C—H...N(nitrile hydrogen bonding, and C—H...π(aromatic and short Cl...π(aromatic [3.628 (1 Å] interactions consolidate the crystal packing.

(E)-3-Hydr?oxy-13-methyl-16-[4-(methyl?sulfan?yl)benzyl?idene]-7,8,9,11,12,13,15,16-octa?hydro-6H-cyclo?penta?[a]phen?an????thren-17(14H)-one

OpenAIRE

Gunasekaran, B.; Murugan, R.; Narayanan, S. Sriman; Manivannan, V.

2008-01-01

In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methylsulfanyl)benzylidine ring in the two crystallographically independent molecules are 34.05 (10) and 40.53 (15)°. The packing is stabilized by intermolecular O—H...O and C—H...O interactions.

(E-3-Hydroxy-13-methyl-16-[4-(methylsulfanylbenzylidene]-7,8,9,11,12,13,15,16-octahydro-6H-cyclopenta[a]phenanthren-17(14H-one

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R. Murugan

2009-01-01

Full Text Available In the title compound, C26H28O2S, the dihedral angles between the mean plane of the five membered ring and the 4-(methylsulfanylbenzylidine ring in the two crystallographically independent molecules are 34.05 (10 and 40.53 (15°. The packing is stabilized by intermolecular O—H...O and C—H...O interactions.

Phenyl N-phenylcarbamate

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Durre Shahwar

2009-06-01

Full Text Available In the title compound, C13H11NO2, the aromatic rings are oriented at a dihedral angle of 42.52 (12°. The crystal structure is stabilized by intermolecular N—H...O hydrogen bonds, which form infinite one-dimensional polymeric chains extending along the a axis. C—H...π interactions between the aromatic rings are also present.

N,N′-Bis(2-thienylmethylenebenzene-1,4-diamine

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Nai-Wei Dong

2009-09-01

Full Text Available The Schiff base, C16H12N2S2, has been synthesized by refluxing an ethanolic solution of thiophene-2-carbaldehyde and benzene-1,4-diamine. The center of the benzene ring is located on a crystallographic center of inversion. The dihedral angle between the benzene and thiophene rings is 63.6 (1°.

The Dynamical History of Chariklo and Its Rings

Energy Technology Data Exchange (ETDEWEB)

Wood, Jeremy [Hazard Community and Technical College, Community College Drive, Hazard, KY 41701 (United States); Horner, Jonti; Marsden, Stephen C. [Computational Engineering and Science Research Centre, University of Southern Queensland, West Street, Toowoomba, QLD 4350 (Australia); Hinse, Tobias C., E-mail: jeremy.wood@kctcs.edu [Korea Astronomy and Space Science Institute, 776 Daedukdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

2017-06-01

Chariklo is the only small solar system body confirmed to have rings. Given the instability of its orbit, the presence of rings is surprising, and their origin remains poorly understood. In this work, we study the dynamical history of the Chariklo system by integrating almost 36,000 Chariklo clones backward in time for 1 Gyr under the influence of the Sun and the four giant planets. By recording all close encounters between the clones and planets, we investigate the likelihood that Chariklo’s rings could have survived since its capture to the Centaur population. Our results reveal that Chariklo’s orbit occupies a region of stable chaos, resulting in its orbit being marginally more stable than those of the other Centaurs. Despite this, we find that it was most likely captured to the Centaur population within the last 20 Myr, and that its orbital evolution has been continually punctuated by regular close encounters with the giant planets. The great majority (>99%) of those encounters within 1 Hill radius of the planet have only a small effect on the rings. We conclude that close encounters with giant planets have not had a significant effect on the ring structure. Encounters within the Roche limit of the giant planets are rare, making ring creation through tidal disruption unlikely.

Carbonatite ring-complexes explained by caldera-style volcanism.

Science.gov (United States)

Andersson, Magnus; Malehmir, Alireza; Troll, Valentin R; Dehghannejad, Mahdieh; Juhlin, Christopher; Ask, Maria

2013-01-01

Carbonatites are rare, carbonate-rich magmatic rocks that make up a minute portion of the crust only, yet they are of great relevance for our understanding of crustal and mantle processes. Although they occur in all continents and from Archaean to present, the deeper plumbing system of carbonatite ring-complexes is usually poorly constrained. Here, we show that carbonatite ring-complexes can be explained by caldera-style volcanism. Our geophysical investigation of the Alnö carbonatite ring-complex in central Sweden identifies a solidified saucer-shaped magma chamber at ~3 km depth that links to surface exposures through a ring fault system. Caldera subsidence during final stages of activity caused carbonatite eruptions north of the main complex, providing the crucial element to connect plutonic and eruptive features of carbonatite magmatism. The way carbonatite magmas are stored, transported and erupt at the surface is thus comparable to known emplacement styles from silicic calderas.

7-Fluoro-4-oxochromene-3-carbaldehyde

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Mohammad Asad

2011-04-01

Full Text Available In the title compound, C10H5FO3, the chromenone ring is essentially planar, with a maximum deviation of 0.039 (1 Å. The dihedral angle between the fluoro-subsituted benzene ring and the pyran ring is 1.92 (4°. In the crystal, molecules are connected via weak intermolecular C—H...O hydrogen bonds, forming supramolecular ribbons along the b axis. These ribbons are stacked down the a axis.

(2-Pyridyl[5-(2-pyridylcarbonyl-2-pyridyl]methanone

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Zi-jia Wang

2010-10-01

Full Text Available In the centrosymmetric title compound, C17H11N3O2, the dihedral angle between the central and pendant pyridyl rings is 50.29 (9°. In the crystal, molecules stack along the a axis by π–π interactions between the pyridine rings with centroid–centroid distances of 3.845 (2 Å. The N atom and one of the C atoms of the central ring are disordered by symmetry.

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)

Vortices trapped in discrete Josephson rings

International Nuclear Information System (INIS)

Van der Zanta, H.S.J.; Orlando, T.P.; Watanabe, Shinya; Strogatz, S.H.

1994-01-01

We report the first measurements of current- (I-V) characteristics of discrete rings of Josephson junctions. As I is increased, resonant steps appear in the I-V curve, due to phase-locking between a propagating, trapped vortex and the linear waves excited in its wake. Unexpectedly, the phase velocity of the linear waves, not the group velocity, is the physically important quantity and mode numbers outside the Brillouin zone are relevant. Our measurements show that away from the resonant steps, a single vortex can move in an environment with very little damping, making the discrete one-dimensional ring a well-defined model system for the study of ballistic and quantum vortex experiments. ((orig.))

Vortices trapped in discrete Josephson rings

Energy Technology Data Exchange (ETDEWEB)

Van der Zanta, H.S.J. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Orlando, T.P. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Watanabe, Shinya [Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Strogatz, S.H. [Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

1994-12-01

We report the first measurements of current- (I-V) characteristics of discrete rings of Josephson junctions. As I is increased, resonant steps appear in the I-V curve, due to phase-locking between a propagating, trapped vortex and the linear waves excited in its wake. Unexpectedly, the phase velocity of the linear waves, not the group velocity, is the physically important quantity and mode numbers outside the Brillouin zone are relevant. Our measurements show that away from the resonant steps, a single vortex can move in an environment with very little damping, making the discrete one-dimensional ring a well-defined model system for the study of ballistic and quantum vortex experiments. ((orig.)).

Valyl benzyl ester chloride

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Grzegorz Dutkiewicz

2010-02-01

Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

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.

(2-Oxo-2H-benzo[h]chromen-4-ylmethyl morpholine-4-carbodithioate

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Rajni Kant

2012-04-01

Full Text Available In the title compound, C19H17NO3S2, the morpholine ring is in a chair conformation. In the coumarin ring system, the dihedral angle between the benzene and pyran rings is 3.9 (1°. In the crystal, weak C—H...O interactions link the molecules into corrugated layers parallel to (102. The crystal packing also exhibits π–π interactions, with distances of 3.644 (1 and 3.677 (1 Å between the centroids of the benzene rings of neighbouring molecules.

2,4,6-Trimethyl-3,5-bis[(phenylcarbonothioylsulfanylmethyl]benzyl benzenecarbodithioate

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M. Kannan

2010-06-01

Full Text Available In the title compound C33H30S6, the three pendant methylene benzodithioate groups lie to one side of the central benzene ring in a cis-cis-cis `tripod' arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4, 89.68 (4 and 86.74 (4°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13:0.441 (13 ratio.

1-(3,4-Difluorobenzyl-4-(4-methylphenylsulfonylpiperazine

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S. Sreenivasa

2013-07-01

Full Text Available In the title compound, C18H20F2N2O2S, the central piperazine ring adopts a chair conformation. The dihedral angle between the two benzene rings is 40.20°, whereas those between the piperazine ring (considering the best fit plane through all the non-H atoms and the sulfonyl-bound benzene and difluorobenzene rings are 74.96 and 86.16°, respectively. In the crystal, molecules are stacked along the a axis through weak C—H...O and C—H...F interactions.

(1S,3R,8S,9R,10S-2,2-Dichloro-3,7,7,10-tetramethyl-9,10-epoxytricyclo[6.4.0.01,3]dodecane

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Moha Berraho

2010-12-01

Full Text Available The title compound, C16H24Cl2O, was synthesized from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene, which was isolated from the essential oil of the Atlas cedar (cedrus atlantica. The molecule forms an extended sheet of two fused rings which exhibit different conformations. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a chair conformation; the dihedral angle between the two rings is 38.2 (1°.

2-(1H-Benzotriazol-1-yl-1-phenylethanol

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Özden Özel Güven

2010-04-01

Full Text Available In the title compound, C14H13N3O, the benzotriazole ring is oriented at a dihedral angle of 13.43 (4° with respect to the phenyl ring. In the crystal structure, intermolecular O—H...N hydrogen bonds link the molecules into chains along the b axis. Aromatic π–π contacts between benzene rings and between triazole and benzene rings [centroid–centroid distances = 3.8133 (8 and 3.7810 (8 Å, respectively], as well as a weak C—H...π interaction involving the phenyl ring, are also observed.

Crystal structure of 2-cyano-N-(furan-2-ylmethyl-3-(3-nitrophenylpropanamide

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Shivanna Subhadramma

2015-08-01

Full Text Available In the title compound, C15H11N3O4, the acetamide group is inclined to the furan ring by 66.5 (1°. The dihedral angle between the furan ring and the benzene ring is 66.8 (1°. In the crystal, molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers with an R22(12 ring motif. The dimers are linked via two pairs of C—H...O hydrogen bonds to the same acceptor oxygen atom, enclosing R21(6 ring motifs, forming chains along the [101] direction.

(2,7-Dimethoxynaphthalen-1-yl(phenylmethanone

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Noriyuki Yonezawa

2010-10-01

Full Text Available The asymmetric unit of the title compound, C19H16O3, contains three independent conformers. Each of the three conformers has essentially the same feature of non-coplanar aromatic rings whereby the aroyl group at the 1-position of the naphthalene ring is twisted in a perpendicular manner to the naphthalene ring. The dihedral angles between the benzene ring planes and the naphthalene ring systems are 75.34 (7, 86.47 (7 and 76.55 (6° in the three conformers. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonds.

Crystal structures of 4-methoxy-N-(4-methylphenylbenzenesulfonamide and N-(4-fluorophenyl-4-methoxybenzenesulfonamide

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Vinola Z. Rodrigues

2015-11-01

Full Text Available Crystal structures of two N-(arylarylsulfonamides, namely, 4-methoxy-N-(4-methylphenylbenzenesulfonamide, C14H15NO3S, (I, and N-(4-fluorophenyl-4-methoxybenzenesulfonamide, C13H12FNO3S, (II, were determined and analyzed. In (I, the benzenesulfonamide ring is disordered over two orientations, in a 0.516 (7:0.484 (7 ratio, which are inclined to each other at 28.0 (1°. In (I, the major component of the sulfonyl benzene ring and the aniline ring form a dihedral angle of 63.36 (19°, while in (II, the planes of the two benzene rings form a dihedral angle of 44.26 (13°. In the crystal structure of (I, N—H...O hydrogen bonds form infinite C(4 chains extended in [010], and intermolecular C—H...πaryl interactions link these chains into layers parallel to the ab plane. The crystal structure of (II features N—H...O hydrogen bonds forming infinite one dimensional C(4 chains along [001]. Further, a pair of C—H...O intermolecular interactions consolidate the crystal packing of (II into a three-dimensional supramolecular architecture.

5-(4-Bromophenyl-2-(3,4-methylenedioxyphenyl-3-methylsulfanyl-1-benzofuran

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Hong Dae Choi

2009-10-01

Full Text Available The title compound, C22H15BrO3S, crystallizes with four molecules in the asymmetric unit. The 4-bromophenyl rings are rotated out of the benzofuran planes, with dihedral angles for the four molecules of 20.8 (2, 17.8 (2, 23.5 (4 and 23.9 (4°. The dihedral angles between the 3,4-methylenedioxyphenyl ring and the benzofuran plane are 13.5 (2, 7.1 (2, 18.6 (3 and 14.2 (3° in the four molecules. The crystal structure is stabilized by weak nonclassical intermolecular C—H...O hydrogen bonds. The crystal structure also exhibits intermolecular aromatic π–π interactions between the benzene and furan rings and between the 4-bromophenyl and 3,4-methylenedioxyphenyl rings from molecules of the same type; the centroid–centroid distances are 3.92 (1 and 3.79 (1, 3.91 (1, 3.77 (1 and 3.77 (1, and 3.79 (1 and 3.75 (1Å in the four molecules.

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

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

4,4′-Bipyridine–3-(thiophen-3-ylacrylic acid (1/2

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Malaichamy Sathiyendiran

2011-10-01

Full Text Available In the title 1/2 adduct, C10H8N2·2C7H6O2S, the dihedral angle between the pyridine rings is 18.41 (11°. In the thiopheneacrylic acid molecules, the dihedral angles between the respective thiophene and acrylic acid units are 5.52 (17° and 23.92 (9°. In the crystal, the components are linked via O—H...N hydrogen-bonding interactions, forming units of two 3-thiopheneacrylic acid molecules and one 4,4′-bipyridine molecule.

Relation between photochromic properties and molecular structures in salicylideneaniline crystals.

Science.gov (United States)

Johmoto, Kohei; Ishida, Takashi; Sekine, Akiko; Uekusa, Hidehiro; Ohashi, Yuji

2012-06-01

The crystal structures of the salicylideneaniline derivatives N-salicylidene-4-tert-butyl-aniline (1), N-3,5-di-tert-butyl-salicylidene-3-methoxyaniline (2), N-3,5-di-tert-butyl-salicylidene-3-bromoaniline (3), N-3,5-di-tert-butyl-salicylidene-3-chloroaniline (4), N-3,5-di-tert-butyl-salicylidene-4-bromoaniline (5), N-3,5-di-tert-butyl-salicylidene-aniline (6), N-3,5-di-tert-butyl-salicylidene-4-carboxyaniline (7) and N-salicylidene-2-chloroaniline (8) were analyzed by X-ray diffraction analysis at ambient temperature to investigate the relationship between their photochromic properties and molecular structures. A clear correlation between photochromism and the dihedral angle of the two benzene rings in the salicylideneaniline derivatives was observed. Crystals with dihedral angles less than 20° were non-photochromic, whereas those with dihedral angles greater than 30° were photochromic. Crystals with dihedral angles between 20 and 30° could be either photochromic or non-photochromic. Inhibition of the pedal motion by intra- or intermolecular steric hindrance, however, can result in non-photochromic behaviour even if the dihedral angle is larger than 30°.

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

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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.

5-Bromo-3-(4-chlorophenylsulfinyl-2-methyl-1-benzofuran

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Hong Dae Choi

2010-11-01

Full Text Available In the title compound, C15H10BrClO2S, the 4-chlorophenyl ring is oriented approximately perpendicular to the mean plane of the benzofuran ring [dihedral angle = 89.55 (9°]. In the crystal, molecules are linked through weak intermolecular C—H...O hydrogen bonds and and a Br...Br contact [3.783 (3 Å].

3-Methyl-4-(3-methylphenyl-5-(2-pyridyl-4H-1,2,4-triazole

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Dun-Ru Zhu

2009-05-01

Full Text Available In the molecule of the title compound, C15H14N4, the triazole ring is oriented at dihedral angles of 30.8 (2 and 67.4 (2° with respect to the pyridine and benzene rings, respectively. The crystal structure is stabilized by C—H...N hydrogen-bonding interactions, forming chains of molecules along [overline{1}01].

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.

1,1′-Bicyclohexyl-1,1′-diyl 2,2′-bipyridine-3,3′-dicarboxylate

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Hoong-Kun Fun

2012-06-01

Full Text Available The title compound, C24H26N2O4, lies about a crystallographic twofold rotation axis. The cyclohexane rings adopts a chair conformation. The two pyridine rings form a dihedral angle of 41.02 (4°. In the crystal, molecules are linked via C—H...O and C—H...N hydrogen bonds into a layer parallel to the bc plane.

Optimization and Simulation of Machining Parameters in Radial-axial Ring Rolling Process

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Shuiyuan Tang

2011-05-01

Full Text Available Ring rolling is a complicated process, in which rolling parameters influence directly the quality of ring. It is a process method with high productivity and few waste of material, widely used in transportation industry including automotive, shipbuilding, aerospace etc. During the rolling process of large-sized parts, crinkle and hollows often appear on surface, due to inconsistence of rolling motions with the deformation of ring part. Based on radial-axial ring rolling system configuration, motions and forces in rolling process are analyzed, and a dynamic model is formulated. Error of ring's end flatness and roundness are defined as the characteristic parameters of ring quality. The relationship between core roller feed speed, drive roller speed, the upper taper roller feed speed, and quality of ring part are analyzed. The stress and strain of the part are simulated in the Finite Element Method by DEFORM software. The simulation results provide a reference for the definition of ring rolling process parameters. It is able to make the deformation of the part be consistent with the process parameters, and improve product quality considerably.

(E-4-Chloro-N-(2,4,6-trimethylbenzylideneaniline

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Ying Guo

2011-08-01

Full Text Available In the title compound, C16H16ClN, the dihedral angle between the benzene rings is 24.61 (13°. In the crystal, only van der Waals interactions occur between neighbouring molecules.

(E)-Methyl 3-(3,4-dimeth­oxy­phen­yl)-2-[(1,3-dioxoisoindolin-2-yl)meth­yl]acrylate

OpenAIRE

Kannan, D.; Bakthadoss, M.; Lakshmanan, D.; Murugavel, S.

2012-01-01

In the title compound, C21H19NO6, the isoindole ring system is essentially planar [maximum deviation = 0.019 (2) Å for the N atom] and is oriented at a dihedral angle of 51.3 (1)° with respect to the benzene ring. The two methoxy groups are almost coplanar with the attached benzene ring [C—O—C—C = 3.7 (4) and 4.3 (4)°]. The molecular conformation is stabilized by an intramolecular C&...

1-[3-(2-Nitrophenyl-5-phenyl-2-pyrazolin-1-yl]ethanone

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Huan-Mei Guo

2010-07-01

Full Text Available The title compound, C17H15N3O3, was prepared from 1-(2-nitrophenyl-3-phenylprop-2-en-1-one and hydrazine. The dihedral angle between the benzene and phenyl rings is 74.55 (2°. The pyrazoline ring is in a slight envelope conformation with the C atom bonded to the phenyl ring forming the flap. In the crystal structure, weak intermolecular C—H...O hydrogen bonds connect molecules into chains along [100].

3-Hydroxy-2-[(4-hydroxy-3,5-dimethoxyphenyl(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-ylmethyl]-5,5-dimethylcyclohex-2-en-1-one

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Xiao-Hui Yang

2011-02-01

Full Text Available In the title compound, C25H32O7, the 3-hydroxy-5,5-dimethylcyclohex-2-enone rings adopt slightly distorted envelope conformations with the two planes at the base of the envelope forming dihedral angles of 57.6 (4 and 53.9 (9° with the benzene ring. There is an intramolecular hydroxy–ketone O—H...O interaction between the two substituted cyclohexane rings as well as a short intramolecular phenol–methoxy O—H...O interaction.

Crystal structure of 2-amino-N-(2-fluorophenyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxamide

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K. Chandra Kumar

2015-11-01

Full Text Available In the title compound, C15H15FN2OS, the dihedral angle between the planes of the benzothiophene ring system and the fluorobenzene ring is 3.74 (14°. The six-membered ring of the benzothiophene moiety adopts a half-chair conformation. The molecular conformation is consolidated by intramolecular N—H...F and N—H...O hydrogen bonds. In the crystal, molecules are linked by N—H...O hydrogen bonds, generating C(6 [001] chains.

1,1′-[Imidazolidine-1,3-diylbis(methylene]bis(1H-benzotriazole

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Augusto Rivera

2012-02-01

Full Text Available In the title compound, C17H18N8, the imidazolidine ring adopts an envelope conformation with the substituents at the N atoms in trans positions with respect to the central ring. The dihedral angle between the two benzotriazole rings is 71.65 (10°. In the crystal, non-classical C—H...N interactions link the molecules into helical chains along the b axis. The crystal packing is further stabilized by weak C—H...π interactions.

Ethyl 2-{3-[(2-chloro-1,3-thiazol-5-ylmethyl]-4-nitroimino-1,3,5-triazinan-1-yl}acetate

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Chuan-wen Sun

2010-06-01

Full Text Available In the title compound, C11H15ClN6O4S, which belongs to the neonicotinoid class of insecticidally active heterocyclic compounds, the six-membered triazine ring adopts an opened envolope conformation. The planar nitro imine group [dihedral angle between nitro and imine groups = 1.07 (7°] and the thiazole ring are oriented at a dihedral angle of 69.62 (8°. A classical intramolecular N—H...O hydrogen bond is found in the molecular structure. Moreover, one classical intermolecular N—H...N and four non-classical C—H...O and C—H...N hydrogen bonds are also present in the crystal structure. Besides intermolecular hydrogen bonds, the Cl atom forms an intermolecular short contact [3.020 (2 Å] with one of the nitro O atoms.

Crystal structure of 3-benzamido-1-(4-nitrobenzylquinolinium trifluoromethanesulfonate

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Mariana Nicolas-Gomez

2016-05-01

Full Text Available In the title compound, C23H18N3O3+·CF3SO3−, the asymmetric unit contains two crystallographically independent organic cations with similar conformations. Each cation shows a moderate distortion between the planes of the amide groups and the quinolinium rings with dihedral angles of 14.90 (2 and 31.66 (2°. The quinolinium and phenyl rings are slightly twisted with respect to each other at dihedral angles of 6.99 (4 and 8.54 (4°. The trifluoromethanesulfonate anions are linked to the organic cations via N—H...O hydrogen-bonding interactions involving the NH amide groups. In the crystal, the organic cations are linked by weak C—H...O(nitro group interactions into supramolecular chains propagating along the b-axis direction.

Limits to the observation of coherent oscillations in a SQUID ring

International Nuclear Information System (INIS)

Diggins, J.

1995-01-01

Using the quantum mechanical, lumped component model of a SQUID ring we compute the onset of tunnelling and macroscopic superposition behaviour in the parameter space of the ring. In addition, we make a quantitative estimate of the stability required in the environmental flux to sustain a superposition state. Both these features are of crucial importance to the realisation of experiments aimed at revealing such behaviour. (orig.)

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

Electric dipole moment of magnetoexciton in concentric quantum rings

Science.gov (United States)

García, L. F.; Mikhailov, I. D.; Revinova, S. Yu

2017-12-01

We study properties of exciton in a weakly coupled concentric quantum rings, penetrated by an axially directed magnetic flux and subjected to an electric field in the ring’s plane. To this end, we adopt a simple model of quasi-one-dimensional rotator, for which the wave functions and the corresponding energies we found by using the double Fourier series expansion method. Revealed multiple intersections of the energy levels provide conditions for abrupt changes of the radial and the angular quantum numbers, making possible the tunnelling of carriers between rings and allowing the formation of a permanent large dipole moment. We show that the electric and magnetic polarizability of concentric quantum rings with a trapped exciton are very sensible to external electric and magnetic fields.

Thermal degradation kinetics and solid state, temperature ...

Indian Academy of Sciences (India)

WINTEC

proceeds due to the oxidation of sulphur atom in the ring to sulphoxide, for the .... grain boundaries etc. Electrical properties ... The spatial orientation in phenothiazine ... atom points outside with respect to the dihedral angle. The two forms are ...

Diaquabis(4-bromobenzoato-κObis(nicotinamide-κN1copper(II

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Hacali Necefoğlu

2011-07-01

Full Text Available The asymmetric unit of the title mononuclear CuII complex, [Cu(C7H4BrO22(C6H6N2O2(H2O2], contains one half-molecule, the CuII atom being located on an inversion center. The unit cell contains two nicotinamide (NA, two 4-bromobenzoate (PBB ligands and two coordinated water molecules. The four O atoms in the equatorial plane around the CuII ion form a slightly distorted square-planar arrangement, while the slightly distorted octahedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxylate group and the adjacent benzene ring is 22.17 (16°, while the pyridine ring and the benzene ring are oriented at a dihedral angle of 82.80 (6°. In the crystal, N—H...O, O—H...O and C—H...O hydrogen bonds link the molecules into a three-dimensional network. A weak C—H...π interaction is also observed.

Crystal structure of 1-isopropyl-4,7-dimethyl-3-nitronaphthalene

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Ahmed Benharref

2015-09-01

Full Text Available The title compound, C15H17NO2, was synthesized from a mixture of α-himachalene (2-methylene-6,6,9-trimethylbicyclo[5.4.01,7]undec-8-ene and β-himachalene (2,6,6,9-tetramethylbicyclo[5.4.01,7]undeca-1,8-diene, which were isolated from an oil of the Atlas cedar (Cedrus Atlantica. The naphthalene ring system makes dihedral angles of 68.6 (2 and 44.3 (2°, respectively, with its attached isopropyl C/C/C plane and the nitro group. In the crystal, molecules held together by a C—H...O interaction, forming a chain along [-101].

1-(3-Cyano­phen­yl)-3-(2-furo­yl)thio­urea

Science.gov (United States)

Theodoro, Jahyr E.; Mascarenhas, Yvonne; Ellena, Javier; Estévez-Hernández, Osvaldo; Duque, Julio

2008-01-01

The title compound, C13H9N3O2S, was synthesized from furoyl isothio­cyanate and 3-amino­benzonitrile in dry acetone. The thio­urea group is in the thio­amide form. The thio­urea fragment makes dihedral angles of 3.91 (16) and 37.83 (12)° with the ketofuran group and the benzene ring, respectively. The mol­ecular geometry is stabilized by N—H⋯O hydrogen bonds. In the crystal structure, centrosymmetrically related mol­ecules are linked by two inter­molecular N—H⋯S hydrogen bonds to form dimers. PMID:21202835

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.

(Z-N-[3-(4-Bromobenzoyl-1,3-thiazolidin-2-ylidene]cyanamide

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Ling Xu

2010-12-01

Full Text Available In the title compound, C11H8BrN3OS, the dihedral angle between the benzene and thiazolidine rings is 63.4 (2°. Intermolecular C—H...N interactions help to stabilize the crystal structure.

1-(3-Fluorophenyl-3-(4-nitrophenylurea

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Mu-Sen Lin

2012-07-01

Full Text Available In the title compound, C13H10FN3O3, the dihedral angle between the fluorophenyl and nitrophenyl ring planes is 6.51 (9°. The crystal structure features N—H...O hydrogen bonds.

A new production technique for wear resistant ring-hammers

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Li Shifeng

2011-11-01

Full Text Available Based on a great number of laboratory experiments, a new technique has been developed for producing wear resistant ring-hammers. In this technology, lost foam casting with iron sand was combined to make mold; a special alloy was used to inoculate the molten steel, and proper heat treatment was used to further improve mechanical properties of wear resistant ring-hammers. The influence of this new production technology on the microstructure and mechanical properties of wear resistant ring-hammers was studied. Results show that iron sand molding, having the inherent characteristic of sand molding, changes the type of metallic compounds, refines crystal grains and increases the fineness of microstructure. Practical experience verified that the properties of the ring-hammers produced with this new technique are as follows: tensile strength (Rm 720 MPa, impact toughness (ak > 210 J•cm-2 and hardness > 200 HB. After water quenching from 1,080℃ (holding for 4 h and tempering at 320℃ for 3 h, the best wear resistance is obtained, and the wear resistance is 1.6 times higher than that of common high manganese ring-hammers.

Ethyl 4-oxo-2,3,4,9-tetrahydro-1H-carbazole-3-carboxylate

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Cevher Gündoğdu

2011-06-01

Full Text Available In the title compound, C15H15NO3, the carbazole skeleton includes an ethoxycarbonyl group at the 3-position. In the indole ring system, the benzene and pyrrole rings are nearly coplanar, forming a dihedral angle of 0.89 (4°. The cyclohexenone ring has an envelope conformation. In the crystal, intermolecular N—H...O and C—H...O hydrogen bonds link the molecules into a three dimensional network. A weak C—H...π interaction is also observed.

Oxidation of 5,6-diamino-1,3-dimethyl-2,4-dioxopyrimidine by perrhenate: the crystal structure of 1,3,6,8-tetramethylpyrimidopteridine-2,4,5,7-tetrone

International Nuclear Information System (INIS)

Booysen, Irvin; Gerber, Thomas I.A.; Mayer, Peter

2008-01-01

The oxidation of 5,6-diamino-1,3-dimethyl-2,4-dioxopyrimidine (H 2 ddd) by perrhenate (ReO 4 - ) led to the formation of 1,3-dimethylalloxan, which condenses with unoxidized H 2 ddd to yield the product 1,3,6,8-tetramethylpyrimidopteridine-2,4,5,7-tetrone (tppt). The structure of tppt consists of a central pyrazine ring and two terminal pyrimidine rings in cis positions. The dihedral angles between the pyrazine and pyrimidine rings are 1.08 deg and 1.20 deg. (author)

Piperazin-1-ium 4-aminobenzoate monohydrate

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P. Sivakumar

2016-05-01

Full Text Available The asymmetric unit of the title hydrated salt, C4H11N2+·C7H6NO2−·H2O, contains a piperazin-1-ium cation, a 4-aminobenzoate anion and a water molecule. One NH group of the piperazine ring is protonated and this ring adopts a chair conformation. The anion of this salt is generated by deprotonation of the OH group of the carboxylic acid substituent of 4-aminobenzoic acid. The benzene ring makes a dihedral angle of 2.6 (2° with the carboxylate substituent. The anion and the solvent water molecule are linked by an N—H...O hydrogen bond. Additional N—H...O and O—H...O hydrogen bonds connect adjacent anions through the water molecules, generating a two-dimensional network parallel to (100, forming R33(12 ring motifs. Adjacent cations are linked by N—H...N hydrogen bonds into infinite chains along (001. These chains are linked to the two-dimensional network of anions and water molecules by another N—H...O hydrogen bond, forming a three-dimensional network.

Diallyl 5-[(4-hexyloxyphenyliminomethyl]-m-phenylene dicarbonate

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Ana María Herrera-González

2009-11-01

Full Text Available The title molecule, C27H31NO7, an imine derivative bearing both carbonate and allyl functionalities, was synthesized in the hope of obtaining a mesogenic polymerizable material. The allylcarbonate arms are fully disordered over two sets of sites, reflecting a large degree of rotational freedom about σ bonds [occupancies: 0.665 (9/0.335 (9 for one substituent, 0.564 (9/0.436 (9 for the other]. In contrast, the hexyl chain is ordered, and presents the common all-trans extended conformation. The benzene rings connected via the imine group make a dihedral angle of 9.64 (11°. In the crystal, the Y-shaped molecules are weakly associated into centrosymmetric dimers through pairs of C—H...O(hexyl contacts. The resulting layers of dimers, approximately parallel to (2overline{2}5, are closely packed in the crystal, allowing π...π interactions between benzene rings of neighboring layers: the separation between the centroid of the benzene ring substituted by allylcarbonate and the centroid of the benzene ring bearing the hexyloxy group in the adjacent layer is 3.895 (1 Å.

Diallyl 5-[(4-hexyl-oxyphen-yl)imino-meth-yl]-m-phenyl-ene dicarbonate.

Science.gov (United States)

Herrera-González, Ana María; López-Velázquez, Delia; Bernès, Sylvain

2009-10-23

The title mol-ecule, C(27)H(31)NO(7), an imine derivative bearing both carbonate and allyl functionalities, was synthesized in the hope of obtaining a mesogenic polymerizable material. The allyl-carbonate arms are fully disordered over two sets of sites, reflecting a large degree of rotational freedom about σ bonds [occupancies: 0.665 (9)/0.335 (9) for one substituent, 0.564 (9)/0.436 (9) for the other]. In contrast, the hexyl chain is ordered, and presents the common all-trans extended conformation. The benzene rings connected via the imine group make a dihedral angle of 9.64 (11)°. In the crystal, the Y-shaped mol-ecules are weakly associated into centrosymmetric dimers through pairs of C-H⋯O(hex-yl) contacts. The resulting layers of dimers, approximately parallel to (25), are closely packed in the crystal, allowing π⋯π inter-actions between benzene rings of neighboring layers: the separation between the centroid of the benzene ring substituted by allyl-carbonate and the centroid of the benzene ring bearing the hex-yloxy group in the adjacent layer is 3.895 (1) Å.

Ring-shaped Wigner crystals of trapped ions at the micronscale

Science.gov (United States)

Li, Haokun; Urban, Erik; Noel, Crystal; Chuang, Alexander; Xia, Yang; Hemmerling, Borge; Wang, Yuan; Zhang, Xiang; Haeffner, Hartmut

Trapped ion crystals are ideal platforms to study many-body physics and quantum information processing, with both the internal electronic states and external motional degree-of-freedoms controllable at the single quantum level. In contrast to conventional, finite, linear chains of ions, a ring topology exhibiting periodic boundary conditions and rotational symmetry opens up a new directions to diverse topics. However, previous implementations of ion rings result in small aspect ratios (electrode distance to ring diameter, making the rotational symmetry of the ion crystals prone to stray electric fields from imperfections of the trap electrodes, particularly evident at low temperatures. Here, using a new trap design with a 60-fold improvement of this aspect ratio, we demonstrate crystallization of 40Ca+ ions in a ring with rotational energy barriers comparable to the thermal energy of Doppler laser cooled ion crystals. When further reducing the rotational energy barriers, we observe delocalization of the ion rings. With this result, we enter a regime where quantum topological effects can be studied and novel quantum computation and simulation experiments can be implemented.

8-[(3-Phenyl-1,2,4-oxadiazol-5-ylmethoxy]quinoline monohydrate

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Shu-Yuan Bai

2013-07-01

Full Text Available In the title compound, C18H13N3O2·H2O, the oxadiazole ring forms dihedral angles 7.21 (10 and 21.25 (11° with the quinoline and benzene rings, respectively. The crystal structure features O—H...N hydrogen bonds and is further consolidated by C—H...O hydrogen-bonding interactions involving the water molecule of hydration.

2-Methoxy-4,6-diphenylnicotinonitrile

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Joel T. Mague

2014-02-01

Full Text Available In the title compound, C19H14N2O, the phenyl rings form dihedral angles of 10.90 (10 and 42.14 (6° with pyridine ring and an angle of 35.7 (2° with each other. The orientation of the methoxy group is defined by the C—O—C—N torsion angle of 4.9 (2°.

N,N′-Bis(diphenylmethylbenzene-1,4-diamine

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Aeed S. Al-Fahdawi

2014-01-01

Full Text Available The complete molecule of the title compound, C32H28N2, is generated by crystallographic inversion symmetry. The dihedral angles between the central aromatic ring and the pendant adjacent rings are 61.37 (16 and 74.20 (14°. The N—H group does not participate in hydrogen bonds and there are no aromatic π–π stacking interactions in the crystal.

4-(2-Fluoropyridin-5-ylphenol

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Fazal Elahi

2012-07-01

Full Text Available In the title compound, C11H8FNO, the aromatic rings are oriented at a dihedral angle of 31.93 (6°. In the crystal, molecules are linked by O—H...N hydrogen bonds, forming C(9 chains propagating along the c-axis direction. There are aromatic π–π stacking interactions between the pyridine rings [centroid–centroid separation = 3.7238 (16 Å].

4,5,6,7-Tetrabromo-1,1,3-trimethyl-3-(2,3,4,5-tetrabromophenylindane

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Alan J. Lough

2008-02-01

Full Text Available The title compound (OctaInd, C18H12Br8, is a commercial brominated flame retardant (BFR. In the molecule, the five-membered ring has a slight envelope conformation, with a deviation of 0.317 (9 Å for the flap C atom from four essentially planar C atoms. The dihedral angle between the two benzene rings is 74.00 (16 Å.

2-{[4-(1,3-Benzothiazol-2-ylphenyl](methylamino}acetic acid

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Yong Zhang

2009-11-01

Full Text Available In the title compound, C16H14N2O2S, the dihedral angle between the benzothiazole ring system and benzene ring is 3.11 (2°. In the crystal structure, intermolecular O—H...N hydrogen bonds link molecules into chains along [100] and these chains are, in turn, linked into a three-dimensional network via weak intermolecular C—H...O hydrogen bonds.

N-(4-Fluorophenyl-2,6-dimethyl-1,3-dioxan-4-amine

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Gottimukkala Rambabu

2013-11-01

Full Text Available In the title compound, C12H16FNO2, the dioxane ring adopts a chair conformation with the methyl substituents and the C—N bond in equatorial orientations. Its mean plane subtends a dihedral angle of 40.17 (6° with the benzene ring. In the crystal, weak N—H...F hydrogen bonds link the molecules into C(7 chains propagating in [100].

2-Ethoxy-4-[2-(3-nitrophenylhydrazonomethyl]phenol

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Jun-Qiang Chen

2009-10-01

Full Text Available The title Schiff base compound, C15H15N3O4, was prepared from a condensation reaction of 3-ethoxy-4-hydroxybenzaldehyde and 3-nitrophenylhydrazine. The molecule is nearly planar; the dihedral angle between the hydroxybenzene ring and the nitrobenzene ring is 6.57 (7°. O—H...O, O—H...N and C—H...O hydrogen bonding helps to stabilize the crystal structure.

Conceptual design of a moving-ring reactor

International Nuclear Information System (INIS)

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

1983-01-01

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

3′,6′-Bis(ethylamino-2′,7′-dimethyl-2-{2-(E-[(thiophen-2-ylmethylideneamino]ethyl}spiro[isoindoline-1,9′-xanthen]-3-one methanol monosolvate

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Rui Guo

2012-05-01

Full Text Available The title compound, C33H34N4O2S·CH3OH, was prepared as a spirolactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spirolactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3 and 0.072 (6 Å, respectively]. The dihedral angles formed by the spirolactam and thiophene rings with the xanthene ring system are 89.7 (6 and 86.5 (2°, respectively. The crystal structure features N—H...O and C—H...O hydrogen bonds.

1,2-Bis(4-ethynylphenyldisulfane

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Hong-Jun Zhu

2010-03-01

Full Text Available In the title compound, C16H10S2, the S atoms are almost coplanar with the benzene rings to which they are bonded [deviations of 0.092 (1 and 0.022 (1 Å from their respective ring planes]. The benzene rings enclose a dihedral angle of 79.17 (3°. An intramolecular C—H...S hydrogen bond results in the formation of a five-membered ring. In the crystal structure, molecules are stacked parallel to the a axis direction. π–π interactions between benzene rings are present, with a face-to-face stacking distance of 3.622 (10 Å.

Ethyl 1-oxo-1,2,3,4-tetrahydro-9H-carbazole-3-carboxylate

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Tuncer Hökelek

2009-07-01

Full Text Available The title compound, C15H15NO3, contains a carbazole skeleton with an ethoxycarbonyl group at the 3 position. In the indole ring system, the benzene and pyrrole rings are nearly coplanar, forming a dihedral angle of 1.95 (8°. The cyclohexenone ring has an envelope conformation. In the crystal structure, pairs of strong N—H...O hydrogen bonds link the molecules into centrosymmetric dimers with R22(10 ring motifs. π–π contacts between parallel pyrrole rings [centroid–centroid distance = 3.776 (2 Å] may further stabilize the structure. A weak C—H...π interaction is also observed.

1-Acetyl-3-ferrocenyl-5-(2-nitrophenyl-2-pyrazoline

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Orhan Büyükgüngör

2008-04-01

Full Text Available In the title compound, [Fe(C5H5(C16H14N3O3], the pyrazoline ring and the substituted cyclopentadienyl ring are nearly coplanar, with a dihedral angle of 8.17 (2°, while the nitro-substituted benzene ring is twisted out of the pyrazoline ring plane by 70.76 (1°. The molecules in the crystal structure are held together by three intermolecular C—H...O hydrogen bonds. There is also an intramolecular C—H...N hydrogen bond. The H atoms of the methyl group are disordered equally over two positions.

1-Benzyl-3′-[(1H-indol-3-ylcarbonyl]-1′-methyl-2-oxo-4′-(pyridin-3-ylspiro[indoline-3,2′-pyrrolidine]-3′-carbonitrile

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P. Seethalakshmi

2016-11-01

Full Text Available In the title compound, C34H27N5O2, the central pyrrolidine ring adopts an envelope conformation, with the N atom as the flap. The mean planes of the two indoline ring systems are inclined to the mean plane of the central pyrrolidine ring by 86.26 (9 and 69.30 (9°, respectively. The dihedral angle between the benzene and pyridine rings is 75.09 (11°. In the crystal, molecules are linked by N—H...N and C—H...N hydrogen bonds, forming sheets parallel to the ab plane.

Amplitude and polarization asymmetries in a ring laser

Science.gov (United States)

Campbell, L. L.; Buholz, N. E.

1971-01-01

Asymmetric amplitude effects between the oppositely directed traveling waves in a He-Ne ring laser are analyzed both theoretically and experimentally. These effects make it possible to detect angular orientations of an inner-cavity bar with respect to the plane of the ring cavity. The amplitude asymmetries occur when a birefringent bar is placed in the three-mirror ring cavity, and an axial magnetic field is applied to the active medium. A simplified theoretical analysis is performed by using a first order perturbation theory to derive an expression for the polarization of the active medium, and a set of self-consistent equations are derived to predict threshold conditions. Polarization asymmetries between the oppositely directed waves are also predicted. Amplitude asymmetries similar in nature to those predicted at threshold occur when the laser is operating in 12-15 free-running modes, and polarization asymmetry occurs simultaneously.

Crystal structure of 4-aminopyridinium 5-(5-chloro-2,4-dinitrophenyl-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate hemihydrate

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Manickkam Vaduganathan

2014-10-01

Full Text Available The title molecular salt, C5H7N2+·C12H8ClN4O7−·0.5H2O, crystallizes as a hemihydrate. The two rings in the barbiturate anion are not coplanar but make a dihedral angle of 43.17 (16°. The two nitro groups deviate from the ring to which they are attached; the nitro group ortho with respect to the ring junction is more deviated [39.3 (4°] than that in the para position [4.2 (5°], probably to overcome steric hindrance. As a result of this, the latter nitro group is more involved in delocalizing the negative charge of the anion than the former nitro group. In the crystal, the cations and anions are linked via N—H...O hydrogen bonds forming zigzag chains along [10-1]. The chains are linked by O—H...O and C—H...O hydrogen bonds, forming slabs lying parallel to (10-1. Further C—H...O hydrogen bonds link the slabs, forming a three-dimensional structure.

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.

Token Ring Project

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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

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.

A Reconfigurable Mesh-Ring Topology for Bluetooth Sensor Networks

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Ben-Yi Wang

2018-05-01

Full Text Available In this paper, a Reconfigurable Mesh-Ring (RMR algorithm is proposed for Bluetooth sensor networks. The algorithm is designed in three stages to determine the optimal configuration of the mesh-ring network. Firstly, a designated root advertises and discovers its neighboring nodes. Secondly, a scatternet criterion is built to compute the minimum number of piconets and distributes the connection information for piconet and scatternet. Finally, a peak-search method is designed to determine the optimal mesh-ring configuration for various sizes of networks. To maximize the network capacity, the research problem is formulated by determining the best connectivity of available mesh links. During the formation and maintenance phases, three possible configurations (including piconet, scatternet, and hybrid are examined to determine the optimal placement of mesh links. The peak-search method is a systematic approach, and is implemented by three functional blocks: the topology formation block generates the mesh-ring topology, the routing efficiency block computes the routing performance, and the optimum decision block introduces a decision-making criterion to determine the optimum number of mesh links. Simulation results demonstrate that the optimal mesh-ring configuration can be determined and that the scatternet case achieves better overall performance than the other two configurations. The RMR topology also outperforms the conventional ring-based and cluster-based mesh methods in terms of throughput performance for Bluetooth configurable networks.

2-Fluoro-5-(4-fluorophenylpyridine

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Fazal Elahi

2012-07-01

Full Text Available In the title compound, C11H7F2N, the fluorobenzene and the 2-fluoropyridine rings are oriented at a dihedral angle of 37.93 (5°. In the crystal, only van der Waals interactions occur.

2-(Biphenyl-4-ylacetic acid (felbinac

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Lynne S. Taylor

2010-10-01

Full Text Available The structure of the title compound, C14H12O2, displays the expected intermolecular hydrogen bonding of the carboxylic acid groups, forming dimers. The dihedral angle between the two aromatic rings is 27.01 (7°.

Crystal structure of (E-1-(4′-methoxy-[1,1′-biphenyl]-4-yl-3-(3-nitrophenylprop-2-en-1-one

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T. Vidhyasagar

2015-01-01

Full Text Available The title compound, C22H17NO4, crystallizes with two independent molecules (A and B in the asymmetric unit. Each molecule exists as an E isomer with C—C=C—C torsion angles of −175.69 (17 and −178.41 (17° in A and B, respectively. In molecule A, the planes of the terminal benzene rings are twisted by an angle of 26.67 (10°, while the biphenyl unit is non-planar, the dihedral angle between the rings being 30.81 (10°. The dihedral angle between the nitrophenyl ring and the inner phenyl ring is 6.50 (9°. The corresponding values in molecule B are 60.61 (9, 31.07 (8 and 31.05 (9°. In the crystal, molecules are arranged in a head-to-head manner, with the 3-nitrophenyl groups nearly parallel to one another. The A and B molecules are linked to one another via C—H...O hydrogen bonds, forming chains lying parallel to (-320 and enclosing R22(10 and R22(12 ring motifs. The methoxy group in both molecules is positionally disordered with a refined occupancy ratio of 0.979 (4:0.021 (4 for molecule A and 0.55 (4:0.45 (4 for molecule B.

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

Analogue Between Dynamic Hamiltonian-Operators of a Mesoscopic Ring Carrying Persistent Current and a Josephson Junction

International Nuclear Information System (INIS)

Fan Hongyi; Wang Jisuo

2006-01-01

By making the analogy between the operator Hamiltonians of a mesoscopic ring carrying the persistent current and a Josephson junction we have introduced a phase operator and entangled state representation to establish a theoretical formalism for the ring system.

Inductive fault current limiter based on multiple superconducting rings of small diameter

International Nuclear Information System (INIS)

Osorio, M R; Cabo, L; Veira, J A; Vidal, F

2004-01-01

We present a fault current limiter prototype based on the use of a secondary comprised of an array of magnetic cores of small sections, each one of them with several superconducting rings. The main advantage of this configuration is that it is easier to make small diameter superconducting rings which, in addition, are more homogeneous and allow better refrigeration. We then present detailed measurements that show that, in addition to these advantages, this prototype offers the same limitation performances than when using a unique core and a superconducting ring with an equivalent area as the array of small section cores

2-Methyl-N-(4-methylbenzoylbenzenesulfonamide

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B. Thimme Gowda

2010-04-01

Full Text Available The asymmetric unit of the title compound, C15H15NO3S, contains two independent molecules. The conformations of the N—C bonds in the C—SO2—NH—C(O segments have gauche torsions with respect to the SO bonds. Further, the molecules are twisted at the S atoms with torsion angles of −53.1 (2 and 61.2 (2° in the two molecules. The dihedral angles between the sulfonyl benzene rings and the —SO2—NH—C—O segments are 86.0 (1 and 87.9 (1°. Furthermore, the dihedral angles between the sulfonyl and the benzoyl benzene rings are 88.1 (1 and 83.5 (1° in the two molecules. In the crystal, molecules are linked by N—H...O(S hydrogen bonds.

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.

Crystal structures of 4-meth-oxy-N-(4-methyl-phenyl)benzene-sulfonamide and N-(4-fluoro-phenyl)-4-meth-oxy-benzene-sulfonamide.

Science.gov (United States)

Rodrigues, Vinola Z; Preema, C P; Naveen, S; Lokanath, N K; Suchetan, P A

2015-11-01

Crystal structures of two N-(ar-yl)aryl-sulfonamides, namely, 4-meth-oxy-N-(4-methyl-phen-yl)benzene-sulfonamide, C14H15NO3S, (I), and N-(4-fluoro-phen-yl)-4-meth-oxy-benzene-sulfonamide, C13H12FNO3S, (II), were determined and analyzed. In (I), the benzene-sulfonamide ring is disordered over two orientations, in a 0.516 (7):0.484 (7) ratio, which are inclined to each other at 28.0 (1)°. In (I), the major component of the sulfonyl benzene ring and the aniline ring form a dihedral angle of 63.36 (19)°, while in (II), the planes of the two benzene rings form a dihedral angle of 44.26 (13)°. In the crystal structure of (I), N-H⋯O hydrogen bonds form infinite C(4) chains extended in [010], and inter-molecular C-H⋯πar-yl inter-actions link these chains into layers parallel to the ab plane. The crystal structure of (II) features N-H⋯O hydrogen bonds forming infinite one dimensional C(4) chains along [001]. Further, a pair of C-H⋯O inter-molecular inter-actions consolidate the crystal packing of (II) into a three-dimensional supra-molecular architecture.

Assembly of silver nanowire ring induced by liquid droplet

Science.gov (United States)

Seong, Baekhoon; Park, Hyun Sung; Chae, Ilkyeong; Lee, Hyungdong; Wang, Xiaofeng; Jang, Hyung-Seok; Jung, Jaehyuck; Lee, Changgu; Lin, Liwei; Byun, Doyoung

2017-11-01

Several forces in the liquid droplet drive the nanomaterials to naturally form an assembled structure. During evaporation of a liquid droplet, nanomaterials can move to the rim of the droplet by convective flow and capillary flow, due to the difference in temperature between the top and contact line of the droplet. Here, we demonstrate a new, simple and scalable technology for the fabrication of ring-shaped Ag NWs by a spraying method. We experimentally identify the compressive force of the droplet driven by surface tension as the key mechanism for the self-assembly of ring structures. We investigated the progress of ring shape formation of Ag NWs according to the droplet size with theoretically calculated optimal conditions. As such, this self-assembly technique of making ring-shaped structures from Ag NWs could be applied to other nanomaterials. This work was supported by the New & Renewable Energy R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korea government Ministry of Trade, Industry and Energy. (No. 20163010071630).

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- ...

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

Neutron activation studies of trace elements in tree rings

International Nuclear Information System (INIS)

Tout, R.E.; Gilboy, W.B.; Spyrou, N.M.

1977-01-01

The levels of twelve elements most of which are either considered essential to plant growth or have been detected in air filter samples in an air pollution survey have been monitored in three transverse sections of trees, two elms (ring-porous trees) and one cedar (a conifer). An irradiation time of 10 minutes and a waiting time of 1 minute were selected followed by a 10-minute count. The activated samples were placed on a specially shaped perspex disc situated on a 45-cm 3 Ge(Li) detector. The gamma-ray spectra were subsequently analysed on a 6600 computer, using the library program 'SAMPO' to which subroutines have been added for peak identification and for calculating the mass of elements present. All irradiations were carried out using a thermal neutron flux of 1.5x10 12 ncm -2 sec -1 . Two dimensional distributions of the elements around the tree rings of the section and radially from ring to ring, have been obtained to see if tree rings can be analysed for use as a record of historical pollution. Definite movement of most of these elements between the two main parts of the xylem has occured in all three trees. This makes it seem unlikely that any pollution products taken up from the atmosphere would be retained in the same ring in which they were originally accumulated. Exceptions may occur in the sapwood rings, where a few elements, especially Cl, show directional peaks which do not persist in the heartwood. (T.G.)

Methyl 3′,4′,5′-trimethoxybiphenyl-4-carboxylate

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Sami Nummelin

2013-03-01

Full Text Available In the title compound, C17H18O5, the dihedral angle between the benzene rings is 31.23 (16°. In the crystal, the molecules are packed in an antiparallel fashion in layers along the a axis. In each layer, very weak C—H...O hydrogen bonds occur between the methoxy and methyl ester groups. Weak C—H...π interactions between the 4′- and 5′-methoxy groups and neighbouring benzene rings [methoxy-C–ring centroid distances = 4.075 and 3.486 Å, respectively] connect the layers.

Crystal structure of 2-amino-4-(4-chlorophenyl-1-(4-methylphenyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carbonitrile

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Shaaban K. Mohamed

2015-12-01

Full Text Available In the title compound, C23H20ClN3O, each of the cyclohexene and 1,4-dihydropyridine rings of the 1,4,5,6,7,8-hexahydroquinoline ring system adopts a twisted-boat conformation. The dihedral angle between the two benzene rings is 11.52 (7°. In the crystal, molecules are linked through a pair of amino–nitrile N—H...N hydrogen bonds, forming inversion dimers. These assemble into a three-dimensional network via C—H...O and C—H...π interactions.

(E-4-Chloro-N-[(E-2-methyl-3-phenylallylidene]aniline

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Jim Simpson

2009-02-01

Full Text Available The title Schiff base compound, C16H14ClN, adopts E configurations with respect to both the C=C and C=N bonds. The dihedral angle between the two aromatic rings is 53.27 (4°, while the plane through the C=C—C=N system is inclined at 9.06 (8° to the benzene ring and 44.92 (5° to the chlorobenzene ring. In the crystal structure, weak C—H...Cl and C—H...N hydrogen bonds stack the molecules down the a axis.

1-[(1R,2S,4R,7S-3,3-Dichloro-4,11,11-trimethyltricyclo[5.4.0.02,4]undecan-7-yl]ethanone

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Ahmed Benharref

2017-02-01

Full Text Available The title compound, C16H24Cl2O, crystallizes with two independent molecules in the asymmetric unit. Each molecule is built up from two fused six-membered rings, one of which is fused to a three-membered ring. The two molecules differ essentially in the orientation of two of the methyl groups. The dihedral angles between the mean planes through the two six-membered rings are 57.98 (13 and 55.29 (13°. The molecular conformation is stabilized by intramolecular C—H...Cl hydrogen bonds.

2-Hydroxy-1,6,7,8-tetramethoxy-3-methylanthraquinone

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Shu-Juan Yu

2008-02-01

Full Text Available The title compound, C19H18O7, also known as chrysoobtusin, was isolated from Cassia tora L. (Leguminosae. The anthraquinone ring system is almost planar, the dihedral angle between the two benzene rings being 4.27 (4°. The structure is stabilized by intra- and intermolecular O—H...O and C—H...O hydrogen bonds, and by weak π–π stacking interactions along the b axis, with a centroid–centroid distance between related benzene rings of 3.800 (4 Å.

5-(Thiophen-2-ylmethyl-1,3,4-thiadiazol-2-amine

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Jerry P. Jasinski

2012-05-01

Full Text Available In the title molecule, C7H7N3S2, the dihedral angle between the thiophene and thiadiazole rings is 72.99 (5°; the two rings are oriented so that the S atoms in each ring are on the same side. In the crystal, the three-dimensional network involves strong N—H...O hydrogen bonds, as well as C—H...π and π–π stacking interactions [centroid–centroid distances = 3.654 (1 and 3.495 (1 Å].

1393 Ring Bus at JPL: Description and Status

Science.gov (United States)

Wysocky, Terry R.

2007-01-01

Completed Ring Bus IC V&V Phase - Ring Bus Test Plan Completed for SIM Project - Applicable to Other Projects Implemented a Avionics Bus Based upon the IEEE 1393 Standard - Excellent Starting Point for a General Purpose High-Speed Spacecraft Bus - Designed to Meet SIM Requirements for - Real-time deterministic, distributed systems. - Control system requirements - Fault detection and recovery Other JPL Projects Considering Implementation F'light Software Ring Bus Driver Module Began in 2006, Continues Participating in Standard Revision. Search for Earth-like planets orbiting nearby stars and measure the masses and orbits of the planets it finds. Survey 2000 nearby stars for planetary systems to learn whether our Solar System is unusual, or typical. Make a new catalog of star position 100 times more accurate than current measurements. Learn how our galaxy formed and will evolve by studying the dynamics of its stars. Critically test models of exactly how stars shine, including exotic objects like black holes, neutron stars and white dwarfs.

Effects of Dihedral Angle on Pool Boiling Heat Transfer from Two Tubes in Vertical Alignment

Energy Technology Data Exchange (ETDEWEB)

Kang, Myeong-Gie [Andong National University, Andong (Korea, Republic of)

2014-10-15

to study the effects of the dihedral angle (α) and the heat flux of the lower tube on heat transfer enhancement of the upper tube, arranged one above the other in the same vertical plane. The combined effects of the dihedral angle and the heat flux of the lower tube on heat transfer enhancement of the upper tube were investigated. The increase in α eventually increases h{sub r} . When α changes from 2 .deg. to 18 .deg. the value of h{sub r} increases about 20.3% for q″{sub L}=10kW/m{sup 2}. The enhancement is clearly observed at the heat fluxes where the convective effect is dominant.

Storm-time ring current: model-dependent results

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N. Yu. Ganushkina

2012-01-01

Full Text Available The main point of the paper is to investigate how much the modeled ring current depends on the representations of magnetic and electric fields and boundary conditions used in simulations. Two storm events, one moderate (SymH minimum of −120 nT on 6–7 November 1997 and one intense (SymH minimum of −230 nT on 21–22 October 1999, are modeled. A rather simple ring current model is employed, namely, the Inner Magnetosphere Particle Transport and Acceleration model (IMPTAM, in order to make the results most evident. Four different magnetic field and two electric field representations and four boundary conditions are used. We find that different combinations of the magnetic and electric field configurations and boundary conditions result in very different modeled ring current, and, therefore, the physical conclusions based on simulation results can differ significantly. A time-dependent boundary outside of 6.6 RE gives a possibility to take into account the particles in the transition region (between dipole and stretched field lines forming partial ring current and near-Earth tail current in that region. Calculating the model SymH* by Biot-Savart's law instead of the widely used Dessler-Parker-Sckopke (DPS relation gives larger and more realistic values, since the currents are calculated in the regions with nondipolar magnetic field. Therefore, the boundary location and the method of SymH* calculation are of key importance for ring current data-model comparisons to be correctly interpreted.

1,3-Bis(4-tert-butylphenyl-4-nitrobutan-1-one

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Dong-Yin Ren

2011-06-01

Full Text Available In the crystal structure of the title compound, C24H31NO3, molecules are connected via C—H...O intermolecular hydrogen bonds, forming dimers. The benzene rings are oriented at a dihedral angle of 29.8 (1°.

(E-4-[(4-Nitrophenyldiazenyl]phenyl anthracene-9-carboxylate

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François Léonard

2008-12-01

Full Text Available In the title compound, C27H17N3O4, the azo group displays a trans conformation and the dihedral angles between the central benzene ring and the pendant anthracene and nitrobenzene rings are 82.94 (7 and 7.30 (9°, respectively. In the crystal structure, weak C—H...O hydrogen bonds, likely associated with a dipole moment present on the molecule, help to consolidate the packing.

2,3-Dibromo-1-(4-chlorophenyl-3-(5-nitro-2-furylpropan-1-one

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Balakrishna Kalluraya

2010-12-01

Full Text Available In the title compound, C13H8Br2ClNO4, the linking –CHBr–CHBr– fragment is disordered over two orientations with refined site occupancies of 0.512 (11 and 0.488 (11. The dihedral angle between the furan ring and the phenyl ring is 21.86 (16°. In the crystal, the molecules are linked into [011] chains by intermolecular C—H...O hydrogen bonds.

Indole-3-thiouronium nitrate

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Martin Lutz

2008-01-01

Full Text Available In the title compound, C9H10N3S+·NO3−, the indole ring system and the thiouronium group are nearly perpendicular, with a dihedral angle of 88.62 (6°. Hydrogen bonding generates two-dimensional networks which are linked to each other via π stacking interactions of the indole groups [average inter-planar ring–ring distance of 3.449 (2 Å].

N-Cyclohexyl-N-ethylbenzenesulfonamide

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Islam Ullah Khan

2009-11-01

Full Text Available The title compound, C14H21NO2S, synthesized by N-methylation of cyclohexylamine sulfonamide with ethyl iodide is of interest as a precursor to biologically active sulfur-containing heterocyclic compounds. There are two independent molecules in the asymmetric unit. The dihedral angles between the mean planes of the phenyl ring and the cyclohexyl ring are 40.29 (11 and 37.91 (13° in the two molecules.

3-Methyl-1-(prop-2-en-1-ylquinoxalin-2(1H-one

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Youssef Ramli

2010-07-01

Full Text Available In the molecule of the title compound, C12H12N2O, the quinoxaline ring is planar with an r.m.s. deviation of 0.007 (15 Å. The dihedral angle between the quinoxaline and propenyl planes is 82.1 (2°. The crystal packing is stabilized by offset π–π stacking between the quinoxaline rings [centroid–centroid distance = 3.8832 (9 Å].

2-Dichloromethyl-N-ethyl-5-(1-phenylsilolan-1-ylcyclopent-3-enecarboxamide

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Han Xiao

2013-10-01

Full Text Available In the title compound, C19H25Cl2NOSi, the NH group and the carbonyl O atom of the amide fragment are involved in an intermolecular N—H...O hydrogen bond forming chains of molecules. The plane of the benzene ring forms a dihedral angle of 50.5 (2° with respect to the silolane ring and an angle of 49.74 (2° with the cyclopentyl moiety.

8-Bromo-2-methylquinoline

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Lin-Tao Yang

2009-07-01

Full Text Available In the crystal structure of the title compound, C10H8BrN, the dihedral angle between the two six-membered rings of the quinoline system is 0.49 (16°. The molecules are packed in a face-to-face arrangement fashion, with a centroid–centroid distance of 3.76 Å between the benzene and pyridine rings of adjacent molecules. No hydrogen bonding is found in the crystal structure.

Ethyl 2-[(5Z-5-(4-methoxybenzylidene-2,4-dioxo-1,3-thiazolidin-3-yl]acetate

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Hamza Tachallait

2016-07-01

Full Text Available In the title compound, C15H15NO5S, the benzene and heterocyclic rings are close to being coplanar [dihedral angle = 1.49 (6°]. In the crystal, pairwise C—H...O hydrogen bonds form dimers, which are arranged into `stair-step' rows by way of C=O–π interactions between a carbonyl group and the benzene ring [O...π = 3.3837 (12 Å].

2-{[(2-Methoxynaphthalen-1-ylmethyl]amino}phenol

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Sara Mahdjoub

2016-07-01

Full Text Available The asymmetric unit of the title compound, C18H17NO2, contains two independent molecules (A and B. The dihedral angle between the naphthalene ring system and the benzene ring is 74.67 (10° in molecule A and 78.81 (9° in molecule B. In the crystal, molecules are linked by a series of C—H...π interactions, forming sheets parallel to the ab plane.

4-Allyl-6-bromo-2-phenyl-4H-imidazo[4,5-b]pyridine monohydrate

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Younès Ouzidan

2010-08-01

Full Text Available In the molecule of the title compound, C15H12BrN3·H2O, the phenyl ring is coplanar with the imidazopyridine ring system [dihedral angle = 0.4 (1°]. The water molecule is disordered over two positions with occupancies of 0.58 (1 and 0.42 (1, and it is linked to the main molecule via an O—H...N hydrogen bond.

2-Hydroxy-1-methoxyanthraquinone monohydrate

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Zhi-Meng Liu

2009-07-01

Full Text Available The title compound, C15H10O4·H2O, also known as alizarin 1-methyl ether monohydrate, was isolated from Morinda officinalis How. The anthraquinone ring system is almost planar, the dihedral angle between the two outer benzene rings being 3.07 (4°. In the crystal structure, O—H...O hydrogen bonds link the organic molecules and the water molecules, forming a three-dimensional network.

4-[(1E)-3-(2,6-Dichloro-3-fluoro-phen-yl)-3-oxoprop-1-en-1-yl]benzonitrile.

Science.gov (United States)

Praveen, Aletti S; Yathirajan, Hemmige S; Narayana, Badiadka; Gerber, Thomas; Hosten, Eric; Betz, Richard

2012-05-01

In the title mol-ecule, C(16)H(8)Cl(2)FNO, the benzene rings form a dihedral angle of 78.69 (8)°. The F atom is disordered over two positions in a 0.530 (3):0.470 (3) ratio. The crystal packing exhibits π-π inter-actions between dichloro-substituted rings [centroid-centroid distance = 3.6671 (10) Å] and weak inter-molecular C-H⋯F contacts.

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

Genetic algorithm for chromaticity correction in diffraction limited storage rings

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M. P. Ehrlichman

2016-04-01

Full Text Available A multiobjective genetic algorithm is developed for optimizing nonlinearities in diffraction limited storage rings. This algorithm determines sextupole and octupole strengths for chromaticity correction that deliver optimized dynamic aperture and beam lifetime. The algorithm makes use of dominance constraints to breed desirable properties into the early generations. The momentum aperture is optimized indirectly by constraining the chromatic tune footprint and optimizing the off-energy dynamic aperture. The result is an effective and computationally efficient technique for correcting chromaticity in a storage ring while maintaining optimal dynamic aperture and beam lifetime.

PEGASYS---A proposed internal target facility for the PEP storage ring

International Nuclear Information System (INIS)

Van Biber, K.

1988-07-01

A proposal for an integral gas-jet target and forward spectrometer for the PEP storage ring is described. The beam structure, allowable, luminosity (L = 10 33 cm/sup /minus/2/s/sup /minus/1/ for H 2 , D 2 ) and energy (E/sub e/ ≤ 15 GeV) make the ring ideal for multiparticle coincidence studies in the scaling regime, and where perturbative QCD may be an apt description of some exclusive and semi-inclusive reactions. 14 refs., 7 figs

Detectability of planetary rings around super-earths by direct infrared imaging

International Nuclear Information System (INIS)

Morel, Carine

2013-01-01

Super-Earths, of which more than 80 have already been discovered, draw a lot of attention. With masses between those of the Earth and Neptune, they are ideal targets for searching for bio-signatures. All the gas giants of the solar system have a ring system, and even the Earth is suspected to have had rings in the past; their presence around super-Earths is thus expected and could give information on the formation process of these planets. The characterization of Super-Earths and their environment has thus become an important goal of modern astronomy. They are still difficult to study because of their small size, but the potential presence of planetary rings can make them easier to observe by the transit method and by direct imaging. This PhD evaluates the possibilities of detecting and characterizing rings around super-Earths by direct infrared imaging with the ELT-METIS instrument. To do this, a model to simulate the thermal emission of a super-Earth and its rings is developed. It is then used to study the influence of physical parameters and orientation of the rings and of planetary orbit on their detectability. The results show that ELT-METIS will be able to detect rings similar to the B and C rings of Saturn, extended within the Roche limit. The super-Earths surrounded by rings will be observable in middle orbit, between about 0.4 and 1 AU, around hot stars within 20 pc of the Sun. It is also shown that the photometric monitoring along the orbit of a super-Earth surrounded by rings should help constrain some of their physical characteristics. (author) [fr

A Bayesian-probability-based method for assigning protein backbone dihedral angles based on chemical shifts and local sequences

Energy Technology Data Exchange (ETDEWEB)

Wang Jun; Liu Haiyan [University of Science and Technology of China, Hefei National Laboratory for Physical Sciences at the Microscale, and Key Laboratory of Structural Biology, School of Life Sciences (China)], E-mail: hyliu@ustc.edu.cn

2007-01-15

Chemical shifts contain substantial information about protein local conformations. We present a method to assign individual protein backbone dihedral angles into specific regions on the Ramachandran map based on the amino acid sequences and the chemical shifts of backbone atoms of tripeptide segments. The method uses a scoring function derived from the Bayesian probability for the central residue of a query tripeptide segment to have a particular conformation. The Ramachandran map is partitioned into representative regions at two levels of resolution. The lower resolution partitioning is equivalent to the conventional definitions of different secondary structure regions on the map. At the higher resolution level, the {alpha} and {beta} regions are further divided into subregions. Predictions are attempted at both levels of resolution. We compared our method with TALOS using the original TALOS database, and obtained comparable results. Although TALOS may produce the best results with currently available databases which are much enlarged, the Bayesian-probability-based approach can provide a quantitative measure for the reliability of predictions.

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.

3-{2-[(3-{(E-2-[4-(Dimethylaminophenyl]ethenyl}quinoxalin-2-yloxy]ethyl}-1,3-oxazolidin-2-one monohydrate

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Youssef Ramli

2012-01-01

Full Text Available In the title compound, C23H24N4O3·H2O, the 1,3-oxazoline ring is nearly planar [maximum deviation = 0.059 (2 Å] and its mean plane is twisted by 30.12 (8° with respect to the quinoxaline fused-ring system; the benzene ring is nearly coplanar with the quinoxaline fused-ring system [dihedral angle = 2.52 (2°]. The water molecule of crystallization is hydrogen-bond donor to an N atom of the quinoxaline ring system as well as an O atom of the oxazolinone unit, the two hydrogen bonds generating a chain running along the c axis.

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

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

Correction of ring artifacts in X-ray tomographic images

DEFF Research Database (Denmark)

Lyckegaard, Allan; Johnson, G.; Tafforeau, P.

2011-01-01

Ring artifacts are systematic intensity distortions located on concentric circles in reconstructed tomographic X-ray images. When using X-ray tomography to study for instance low-contrast grain boundaries in metals it is crucial to correct for the ring artifacts in the images as they may have...... the same intensity level as the grain boundaries and thus make it impossible to perform grain segmentation. This paper describes an implementation of a method for correcting the ring artifacts in tomographic X-ray images of simple objects such as metal samples where the object and the background...... are separable. The method is implemented in Matlab, it works with very little user interaction and may run in parallel on a cluster if applied to a whole stack of images. The strength and robustness of the method implemented will be demonstrated on three tomographic X-ray data sets: a mono-phase β...

Weak incidence algebra and maximal ring of quotients

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Surjeet Singh

2004-01-01

Full Text Available Let X, X′ be two locally finite, preordered sets and let R be any indecomposable commutative ring. The incidence algebra I(X,R, in a sense, represents X, because of the well-known result that if the rings I(X,R and I(X′,R are isomorphic, then X and X′ are isomorphic. In this paper, we consider a preordered set X that need not be locally finite but has the property that each of its equivalence classes of equivalent elements is finite. Define I*(X,R to be the set of all those functions f:X×X→R such that f(x,y=0, whenever x⩽̸y and the set Sf of ordered pairs (x,y with xmakes I*(X,R an R-algebra, called the weak incidence algebra of X over R. In the first part of the paper it is shown that indeed I*(X,R represents X. After this all the essential one-sided ideals of I*(X,R are determined and the maximal right (left ring of quotients of I*(X,R is discussed. It is shown that the results proved can give a large class of rings whose maximal right ring of quotients need not be isomorphic to its maximal left ring of quotients.

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

4,4′-([4,4′-Bipyridine]-1,1′-diium-1,1′-diyldibenzoate dihydrate

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Mark A. Rodriguez

2016-06-01

Full Text Available We report here the synthesis of a neutral viologen derivative, C24H16N2O4·2H2O. The non-solvent portion of the structure (Z-Lig is a zwitterion, consisting of two positively charged pyridinium cations and two negatively charged carboxylate anions. The carboxylate group is almost coplanar [dihedral angle = 2.04 (11°] with the benzene ring, whereas the dihedral angle between pyridine and benzene rings is 46.28 (5°. The Z-Lig molecule is positioned on a center of inversion (Fig. 1. The presence of the twofold axis perpendicular to the c-glide plane in space group C2/c generates a screw-axis parallel to the b axis that is shifted from the origin by 1/4 in the a and c directions. This screw-axis replicates the molecule (and solvent water molecules through space. The Z-Lig molecule links to adjacent molecules via O—H...O hydrogen bonds involving solvent water molecules as well as intermolecular C—H...O interactions. There are also π–π interactions between benzene rings on adjacent molecules.

Crystal structure of trans-diaquabis(4-cyanobenzoato-κObis(nicotinamide-κN1cobalt(II

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Gülçin Şefiye Aşkın

2015-05-01

Full Text Available In the title complex, [Co(C8H4NO22(C6H6N2O2(H2O2], the CoII atom is located on an inversion centre and is coordinated by two 4-cyanobenzoate (CNB anions, two nicotinamide (NA ligands and two water molecules. The four O atoms in the equatorial plane form a slightly distorted square-planar arrangement, while the slightly distorted octahedral coordination sphere is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxylate group and the adjacent benzene ring is 22.11 (15°, while the pyridine and benzene rings are oriented at a dihedral angle of 89.98 (5°. In the crystal, intermolecular N—H...O and O—H...O hydrogen bonds link the molecules, enclosing R22(8 and R44(8 ring motifs, forming layers parallel to (100. The layers are linked via C—H...O and C—H...N hydrogen bonds, resulting in a three-dimensional network. A weak C—H...π interaction is also observed.

5,5′-(Ethyne-1,2-diyldiisophthalic acid dimethyl sulfoxide tetrasolvate

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Alexander S. Münch

2013-06-01

Full Text Available In the title compound, C18H10O8·4C2H6OS, the mid-point of the triple bond of the main molecule is located on a special position, i.e. about an inversion center. The carboxyl groups are twisted slightly out of the planes of the aromatic rings to which they are attached, making dihedral angles of 24.89 (1 and 7.40 (2°. The cystal packing features strong O—H...O hydrogen bonds, weaker C—H...O interactions and O...S contacts [3.0981 (11 Å] and displays channel-like voids extending along the a-axis direction which contain the dimethyl sulfoxide solvent molecules.

N-{(Z-3-Oxo-3-[(E-(pyridin-2-ylmethyldiazenyl]-1-(thiophen-2-ylprop-1-en-2-yl}benzamide

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Devinder K. Sharma

2016-08-01

Full Text Available In the title compound, C20H16N4O2S, the thiophene ring subtends dihedral angles of 58.6 (3 and 9.8 (3° with the benzamide and pyridine rings, respectively, whereas these two rings are inclined to one another by 59.3 (3°. There is an intramolecular C—H...π interaction present involving the pyridine and benzamide rings. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains along the [010] direction. The chains are linked by C—H...S hydrogen bonds and C—H...π interactions, forming sheets parallel to the ab plane.

(3R,5S,7R,8R,9S,10S,12S,13R,14S-10,13-Dimethyl-17-[5-oxo-5-(prop-2-yn-1-yloxypentan-2-yl]hexadecahydro-1H-cyclopenta[a]phenanthrene-3,7,12-triyl triacetate

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T. Kavitha

2017-03-01

Full Text Available In the title compound, C33H48O8, four terminal H atoms of cholic acid are replaced by three acetyl and one terminal alkyne group. All the acetyl residues are twisted with respect to the rings (A, B and C to which they are attached. The cyclopentane ring D adopts an envelope conformation with the methyl-substituted C atom as the flap. Rings A, B and C have chair conformations. The dihedral angle between the mean planes of rings C and D is 4.70 (11°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure.

Crystal structure of 3-methyl-2,6-bis(4-methyl-1,3-thiazol-5-ylpiperidin-4-one

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A. Manimaran

2014-09-01

Full Text Available In the title compound, C14H17N3OS2, the central piperidinone ring adopts a chair conformation and the thiazole rings are inclined to its mean plane by 80.16 (12 and 67.15 (12°. The O atom and methyl group C atom deviate significantly from the mean plane of the central piperidinone ring, by 0.8138 (2 and 0.3175 (2 Å, respectively. The dihedral angle between the thiazole rings is 51.88 (13°. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming zigzag C(10 chains running parallel to [001].

(4-Chloroacetanilido-κ2N,Obis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III

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Lijun Sun

2013-02-01

Full Text Available In the neutral mononuclear iridium(III title compound, [Ir(C8H7ClNO(C11H8N2], the IrIII atom adopts an octahedral geometry, and is coordinated by two 2-phenylpyridyl ligands and one anionic 4-chloroacetanilide ligand. The 2-phenylpyridyl ligands are arranged in a cis-C,C′ and cis-N,N′ fashion. Each 2-phenylpyridyl ligand forms a five-membered ring with the IrIII atom. The 2-phenylpyridyl planes are perpendicular to each other [dihedral angle = 89.9 (1°]. The Ir—C and Ir—N bond lengths are comparable to those reported for related iridium(III 2-phenylpyridyl complexes. The remaining two coordination sites are occupied by the amidate N and O atoms, which form a four-membered ring with the iridium atom (Ir—N—C—O. The amidate plane is nearly perpendicular to both 2-phenylpyridyl ligands [dihedral angles = 87.8 (2 and 88.3 (2°].

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

Crystal structure of bis{2-[(E-(4-fluorobenzyliminomethyl]phenolato-κ2N,O}nickel(II

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Amalina Mohd Tajuddin

2014-10-01

Full Text Available The asymmetric unit of the title complex, [Ni(C14H11FNO2], contains one-half of the molecule with the NiII cation lying on an inversion centre coordinated by a bidentate Schiff base anion. The cationic NiII center is in a distorted square-planar coordination environment chelated by the imine N and phenolate O donor atoms of the two Schiff base ligands. The N and O donor atoms of the two ligands are mutually trans with Ni—N and Ni—O bond lengths of 1.9242 (10 and 1.8336 (9 Å, respectively. The fluorophenyl ring is almost orthogonal to the coordination plane and makes a dihedral angle of 82.98 (7° with the phenolate ring. In the crystal, molecules are linked into screw chains by weak C—H...F hydrogen bonds. Additional C—H...π contacts arrange the molecules into sheets parallel to the ac plane.

Simulation of a resonant-type ring magnet power supply with multiple resonant cells and energy storage chokes

International Nuclear Information System (INIS)

Kim, J.M.S.; Blackmore, E.W.; Reiniger, K.W.

1992-01-01

For the TRIUMF KAON Factory Booster Ring, a resonant-type magnet power supply has been proposed for the dipole magnet excitation. The Booster Ring magnet power supply system based on resonant circuits, coupled with distributed energy make-up networks, is a complex system, sensitive to many system parameters. When multiple resonant cells, each with its own energy make-up network, are connected in a ring, it is very difficult to derive closed-form solutions to determine the operating conditions of the power supply system. A meaningful way to understand and analyze such a complex system is to use a simulation tool. This paper presents the analysis of operating conditions of the resonant-type ring magnet power supply with multiple resonant cells, using the circuit simulation tool, SPICE. The focus of the study is on the effect of circuit parameter variations in energy storage chokes

A rapid protection switching method in carrier ethernet ring networks

Science.gov (United States)

Yuan, Liang; Ji, Meng

2008-11-01

block secondary port on master node for loop avoidance. Ethernet rings may be interconnected through dual nodes with a shared link. In this case, we should fix that which ring on the share link is ctrl-ring, and only ctrl-ring can deal with the failure happens on the share link. Carrier Ethernet is an alternative for traditional MAN technologies. Ethernet ring network which can make CE more reliable is one of the hottest topics in recently years. RRPM can provide protection switching in sub-50ms and process link fault on single ring and interconnected rings.

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.

Alstom Francis Turbine Ring Gates: from Retrofitting to Commissioning

Science.gov (United States)

A, Nguyen P.; G, Labrecque; M-O, Thibault; M, Bergeron; A, Steinhilber; D, Havard

2014-03-01

The Ring Gate synchronisation system developed by Alstom is new and patented. It uses hydraulic cylinders connected in pairs by a serial connection. The new hydraulic synchronisation system, when compared to the previous mechanical synchronisation system, has several advantages. It is a compact design; it reduces the number of mechanical components as well as maintenance costs. The new system maintains the Ring Gates robustness. The new approach is an evolution from mechanical to hydraulic synchronization assisted by electronic control. The new synchronization system eliminates several mechanical components that used to add wear and friction and which are usually difficult to adjust during maintenance. Tension chains and sprockets and associated controls are eliminated. Through the position sensors, the redundancy of the ring gate synchronization system makes it predictable and reliable. The electronic control compensates for any variation in operation, for example a leak in the hydraulic system. An emergency closing is possible without the electronic control system due to the stiffness of hydraulic serial connection in the hydraulic cylinder pairs. The Ring Gate can work safely against uneven loads and frictions. The development will be reviewed and its application discussed through commissioning results.

Alstom Francis Turbine Ring Gates: from Retrofitting to Commissioning

International Nuclear Information System (INIS)

Nguyen P A; Labrecque G; Thibault M-O; Bergeron M; Steinhilber A; Havard D

2014-01-01

The Ring Gate synchronisation system developed by Alstom is new and patented. It uses hydraulic cylinders connected in pairs by a serial connection. The new hydraulic synchronisation system, when compared to the previous mechanical synchronisation system, has several advantages. It is a compact design; it reduces the number of mechanical components as well as maintenance costs. The new system maintains the Ring Gates robustness. The new approach is an evolution from mechanical to hydraulic synchronization assisted by electronic control. The new synchronization system eliminates several mechanical components that used to add wear and friction and which are usually difficult to adjust during maintenance. Tension chains and sprockets and associated controls are eliminated. Through the position sensors, the redundancy of the ring gate synchronization system makes it predictable and reliable. The electronic control compensates for any variation in operation, for example a leak in the hydraulic system. An emergency closing is possible without the electronic control system due to the stiffness of hydraulic serial connection in the hydraulic cylinder pairs. The Ring Gate can work safely against uneven loads and frictions. The development will be reviewed and its application discussed through commissioning results

FUZZY RINGS AND ITS PROPERTIES

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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

(3R,6S,7aS-3-Phenyl-6-(phenylsulfanylperhydropyrrolo[1,2-c]oxazol-5-one

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Anthony D. Woolhouse

2009-05-01

Full Text Available Molecules of the title compound [systematic name: (2R,5S,7S-2-phenyl-7-phenylsulfanyl-1-aza-3-oxabicyclo[3.3.0]octan-8-one], C18H17NO2S, form high quality crystals even though they are only packed using C—H...O(carbonyl and weak C—H...S interactions. The dihedral angle between the aromatic rings is 85.53 (5°. The fused rings adopt envelope and twist conformations.

(5S,6R-6-Bromo-6-methyl-5-phenyl-3,4,5,6-tetrahydro-2H-cyclopenta[b]pyran-7-one

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Winai Ieawsuwan

2011-10-01

Full Text Available The title compound, C15H15BrO2, was synthesized by a Brønsted acid-catalysed domino electrocyclization-halogenation reaction. The five-membered ring is essentially planar (r.m.s. deviation 0.006 Å and forms a dihedral angle of 72.7 (3° with the attached phenyl ring. The six-membered heterocycle adopts a half-chair conformation. The crystal packing is stabilized by a C—H...O contact.

Ethyl 8,13-dioxa-21-azapentacyclo[18.5.1.02,7.014,19.021,25]hexacosa-2(7,3,5,14,16,18-hexaene-26-carboxylate

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Devadasan Velmurugan

2013-01-01

Full Text Available In the title compound, C26H31NO4, the five-membered rings of the central pyrrolizine system adopt N-envelope conformations. The ethyl acetate group adopts an extended conformation. The dihedral angle between the benzene rings is 36.6 (1°. In the crystal, C—H...O hydrogen bonds form a zigzag chain running along the b-axis directions. The crystal structure is futher consolidated by C—H...π interactions.

Crystal structure of N-[(E-(1,3-benzodioxol-5-ylmethylidene]-4-chloroaniline

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J. Pablo García-Merinos

2014-11-01

Full Text Available In the title compound, C14H10ClNO2, obtained by the condensation of 4-chloroaniline and piperonal, the five-membered ring is almost planar (r.m.s. deviation = 0.023 Å and the dihedral angle between the aromatic rings is 43.22 (14°. In the crystal, a short O...Cl contact of 3.173 (2 Å is observed. The molecules are arranged into corrugated (010 layers.

N′-(3,5-Dibromo-2-hydroxybenzylidene-2-methylbenzohydrazide

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Chun-Bao Tang

2010-12-01

Full Text Available The asymmetric unit of the title compound, C15H12Br2N2O2, contains two independent molecules in which the dihedral angles between the benzene rings are 49.5 (7 and 66.4 (7°. Intramolecular O—H...N hydrogen bonds generate S(6 ring motifs in each molecule. In the crystal, molecules are linked through intermolecular N—H...O hydrogen bonds, forming chains along the b axis.

Ethyl 2-cyano-5-oxo-5-(thiophen-2-yl-3-(3,4,5-trimethoxyphenylpentanoate

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M. Prabhuswamy

2012-12-01

Full Text Available In the title compound, C21H23NO6S, the dihedral angle between the thiopene and benzene rings is 88.66 (6°. In the crystal, molecules are connected by C—H...N and C—H...O hydrogen bonds, forming a tape along [10-1]. In addition, C—H...π and π–π stacking [centroid–centroid distance = 3.879 (2 Å between the thiophene rings] interactions are observed.

2-Methyl-3-(2-methylphenyl-7-nitroquinazolin-4(3H-one

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Edward R. T. Tiekink

2012-03-01

Full Text Available In the title methaqualone analogue, C16H13N3O3, the 2-tolyl group is almost orthogonal [dihedral angle = 85.20 (5°] to the fused ring system (r.m.s. deviation of fitted non-H atoms = 0.029 Å. In the crystal, twofold symmetry generates two-molecule aggregates linked by C—H...O and π–π interactions [ring centroid–centroid distance = 3.4967 (6 Å].

Ethyl 4-chloro-2′-fluoro-3-hydroxy-5-methylbiphenyl-2-carboxylate

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Muhammad Adeel

2011-09-01

Full Text Available In the title compound, C16H14ClFO3, the dihedral angle between the mean planes of the two benzene rings is 71.50 (5°. Due to an intramolecular O—H...O hydrogen bond between the hydroxy group and the carbonyl O atom of the ethyl ester group, the ethyl ester group lies within the ring plane. The crystal structure is consolidated by intermolecular C—H...O and C—H...F interactions.

Methyl 2-({6-[(1-methoxy-2-methyl-1-oxopropan-2-ylcarbamoyl]pyridin-2-yl}formamido-2-methylpropanoate

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Abdel-Galil E. Amr

2012-05-01

Full Text Available In the title compound, C17H23N3O6, the two methoxycarbonyl C—O—C=O planes are inclined at dihedral angles of 5.3 (4 and 83.9 (4° with respect to the central pyridine ring. An intramolecular N—H...O hydrogen bond generates an S(5 ring motif. In the crystal, molecules are linked into a chain along the c axis via C—H...O hydrogen bonds.

1,6-Bis[(2,2′:6′,2′′-terpyridin-4′-yloxy]hexane

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Varvara I. Nikolayenko

2012-07-01

Full Text Available The molecule of the title compound, C36H32N6O2, lies about an inversion center, located at the mid-point of the central C—C bond of the diether bridge. The terminal pyridine rings form dihedral angles of 4.67 (7 and 26.23 (7° with the central ring. In the crystal, weak C—H...N and C—H...O interactions link the molecules into a three-dimensional network.

4-Fluoro-N-[(E-3,4,5-trimethoxybenzylidene]aniline

Directory of Open Access Journals (Sweden)

Jiban Podder

2013-08-01

Full Text Available The title compound, C16H16FNO3, exists in a trans configuration with respect to the C=N bond [1.258 (2 Å]. The central methoxy O atom deviates from the plane of the attached benzene ring by 0.0911 (14 Å. The dihedral angle between the aromatic rings is 47.58 (11°. The crystal structure features C—H...N and C—H...O interactions.

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)

Crystal structures of 2,3-bis(4-chlorophenyl-1,3-thiazolidin-4-one and trans-2,3-bis(4-chlorophenyl-1,3-thiazolidin-4-one 1-oxide

Directory of Open Access Journals (Sweden)

Hemant P. Yennawar

2015-03-01

Full Text Available In the crystal structures of the title compounds, C15H11Cl2NOS, (1, and C15H11Cl2NO2S, (2, wherein (2 is the oxidized form of (1, the thiazolidine ring is attached to two chlorophenyl rings. The chlorophenyl ring on the 2-carbon atom position points in the same direction as that of the S atom in (1, while in (2, the S atom points in the opposite direction. The O atom on the chiral S atom in (2 is trans to the chlorophenyl ring on the 2-carbon. The chlorophenyl ring planes in each structure are close to orthogonal, making dihedral angles of 78.61 (6 and 87.46 (8° in (1 and (2, respectively. The thiazolidine ring has a twisted conformation on the S—Cmethine bond in (1, and an envelope conformation with the S atom 0.715 (3 Å out of the plane of other four atoms in (2. In the crystal of (1, molecules are linked by C—H...O hydrogen bonds, as well as by slipped parallel π–π interactions [inter-centroid distance = 3.840 (3 Å] between inversion-related phenyl rings, forming sheets parallel to (001. In the crystal of (2, molecules are linked via C—H...O and C—H...Cl hydrogen bonds, forming slabs parallel to (001.

Butane-1,4-diyl bis(pyridine-4-carboxylate

Directory of Open Access Journals (Sweden)

J. Muthukumaran

2011-07-01

Full Text Available The molecule of the title compound, C16H16N2O4, lies about an inversion centre; the butane chain adopts an extended zigzag conformation. The dihedral angle between the pyridine ring and the adjacent COO group is 3.52 (s14°.

1,5-Bis(1-phenyl-ethyl-idene)thio-carbono-hydrazide.

Science.gov (United States)

Feng, Lei; Ji, Haiwei; Wang, Renliang; Ge, Haiyan; Li, Li

2011-06-01

The title mol-ecule, C(17)H(18)N(4)S, is not planar, as indicated by the dihedral angle of 27.24 (9)° between the two benzene rings. In the crystal, inter-molecular N-H⋯S hydrogen bonds link pairs of mol-ecules into inversion dimers.

Torsion angle dependence of the rectifying performance in molecular device with asymmetrical anchoring groups

International Nuclear Information System (INIS)

Wang, L.H.; Guo, Y.; Tian, C.F.; Song, X.P.; Ding, B.J.

2010-01-01

Using first-principles density functional theory and nonequilibrium Green's function formalism, we investigate the effect of torsion angle on the rectifying characteristics of 4'-thiolate-biphenyl-4-dithiocarboxylate sandwiched between two Au(111) electrodes. The results show that the torsion angle has an evident influence on rectifying performance of such devices. By increasing the dihedral angle between two phenyl rings, namely changing the magnitude of the intermolecular coupling effect, a different rectifying behavior can be observed in these systems. Our findings highlight that the rectifying characteristics are intimately related to dihedral angles and can provide fundamental guidelines for the design of functional molecular devices.

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.

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.

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.

Guide to the Main Ring DO overpass

International Nuclear Information System (INIS)

Turkot, F.

1985-01-01

The DO overpass is a modification of the beam orbit in Main Ring in order to better accommodate a Tevatron collider detector at DO. The orbit is moved up approx. 51 inches over most of the long straight section at DO, thus making the Main Ring the world's first non-planar proton synchrotron. A similar overpass, but with four times the displacement, is planned for the CDF detector at the BO straight section. The nominal separation between the beam orbit in the Main Ring and the orbit in the Tevatron is 25.5 inches. Early in the design study of a detector that would utilize the Tevatron is a anti pp collider, it was apparent that a larger separation at the detector was highly desirable. In 1981, Tom Collins proposed a specific lattice geometry in the Main Ring for achieving larger separation, called ''the screw beam''. His proposal has served as the basis for the design of both the BO and DO overpasses. The main purpose of this report is to describe in some detail the implementation of the DO overpass. Topics to be covered include: (a) geometry of the overpass orbit, (b) the new hardware in the tunnel, (c) the power supply system, (d) the control facility, (e) accelerator beam dynamics ramifications, and (f) commissioning experience. A secondary purpose is to provide a fairly complete ''bibliography'' to the sources of information on the overpass. 17 refs., 17 figs

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.

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.

Analysis of the piston ring/liner oil film development during warm-up for an SI-engine

DEFF Research Database (Denmark)

Frølund, Kent; Schramm, Jesper; Tian, T.

2001-01-01

A one-dimensional ring-pack lubrication model developed at MIT is applied to simulate the oil film behavior during the warm-up period of a Kohler spark ignition engine. This is done by making assumptions for the evolution of the ail temperatures during warm-up and that the oil control ring during...

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.

(E-3-(Anthracen-9-yl-1-(furan-2-ylprop-2-en-1-oneThis paper is dedicated to His Majesty King Bhumibol Adulyadej of Thailand (King Rama IX for his sustainable development of the country.

Directory of Open Access Journals (Sweden)

Jirapa Horkaew

2010-04-01

Full Text Available In the molecule of the title heteroaryl chalcone derivative, C21H14O2, the almost planar prop-2-en-1-one unit [r.m.s. deviation = 0.0087 (1 Å] forms dihedral angles of 5.81 (7 and 49.85 (6°, respectively, with the furan ring and anthracene ring system. In the crystal structure, the molecules are linked into a two-dimensional network parallel to (100 by C—H...O hydrogen bonds and π...π interactions involving the furan rings [centroid–centroid distance = 3.7205 (6 Å].

4-Methyl-2-oxo-2H-chromen-7-yl 4-methoxybenzenesulfonate

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Suman Sinha

2011-12-01

Full Text Available In the title compound, C17H14O6S, the 2H-chromene ring is essentially planar, with a maximum deviation of 0.016 (1 Å. The dihedral angle between the 2H-chromene and the benzene rings is 54.61 (5°. The C atom of the methoxy group is close to coplanar with its attached ring [deviation = 0.082 (2 Å]. In the crystal, molecules are connected via C—H...O hydrogen bonds, forming sheets lying parallel to the bc plane. Weak C—H...π interactions are also observed.

2-Hydroxy-5-nitrobenzaldehyde 2,4-dinitrophenylhydrazone

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2008-04-01

Full Text Available In the title compound, C13H9N5O7, one of the nitro groups is twisted away from the attached benzene ring by 16.21 (8°. The dihedral angle between the two benzene rings is 4.63 (1°. The molecular structure is stabilized by intramolecular N—H...O and O—H...N hydrogen bonds which generate an S(6 ring motif. The molecules pack as layers parallel to the ab plane; molecules of adjacent layers are linked into chains along the [101] direction through N—H...O hydrogen bonds.

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.

1-(Benzyloxynaphthalene

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Perumal Venkatesan

2011-08-01

Full Text Available In the title compound, C17H14O, the dihedral angle between the naphthyl ring system and the benzyl group is 83.22 (4°. Both of these moieties are planar, with mean deviations from their least-squares planes, defined by the naphthyl ring C atoms and the O atom, and the phenyl ring C atoms and the benzyl α-C atom, of 0.0176 (1 and 0.0024 (13 Å, respectively. The crystal structure is stabilized by C—H...π and π–π interactions [centroid–centroid distance = 3.7817 (10 Å].

6-Methoxy-1-(4-methoxyphenyl-1,2,3,4-tetrahydro-9H-β-carbolin-2-ium acetate

Directory of Open Access Journals (Sweden)

Mohd Mustaqim Rosli

2012-05-01

Full Text Available In the title compound, C19H21N2O2+·C2H3O2−, the 1H-indole ring system is essentially planar [maximum deviation = 0.0257 (14 Å] and forms a dihedral angle of 87.92 (7 Å with the benzene ring attached to the tetrahydropyridinium fragment. The tetrahydropyridinium ring adopts a half-chair conformation. In the crystal, cations and anions are linked by interionic N—H...O, C—H...O and C—H...N hydrogen bonds into chains along the a axis.

10a-Hydroxy-9-(4-methoxyphenyl-3,4,5,6,7,8a,9,10a-octahydro-1H-xanthene-1,8(2H-dione

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2012-08-01

Full Text Available In the title compound, C20H22O5, the tetrahydropyran, cyclohexene and cyclohexane rings of the xanthene ring system adopt half-chair, half-boat and chair conformations, respectively. The mean plane of the four roughly planar atoms of the tetrahydropyran ring (r.m.s. deviation = 0.111 Å forms a dihedral angle of 82.91 (4° with the methoxybenzene group. In the crystal, molecules are linked via O—H...O and C—H...O hydrogen bonds into sheets lying parallel to the ac plane. The crystal is further consolidated by weak C—H...π interactions.

1-(6-Chloro-2-methyl-4-phenylquinolin-3-yl-3-(3-methoxyphenylprop-2-en-1-one

Directory of Open Access Journals (Sweden)

Wan-Sin Loh

2010-01-01

Full Text Available In the title compound, C26H20ClNO2, the quinoline ring system is approximately planar with a maximum deviation of 0.028 (2 Å and forms a dihedral angle of 73.84 (5° with the phenyl ring. Two neighbouring molecules are arranged into a centrosymmetric dimer through a pair of intermolecular C—H...Cl interactions. A pair of intermolecular C—H...O hydrogen bonds link two methoxyphenyl groups into another centrosymmetric dimer, generating an R22(8 ring motif. The structure is further stabilized by C—H...π interactions.

(1S,1′S,2′R,4a'S,9a'S,9b'R-1′-Acetyloxy-2,4′-dioxo-2′,4′,4a',7′,8′,9′,9a',9b'-octahydro-1′H,2H-spiro[acenaphthylene-1,5′-pyrano[4,3-a]pyrrolizin]-2′-ylmethyl acetate

Directory of Open Access Journals (Sweden)

S. Santhiya

2013-11-01

Full Text Available In the title compound C26H25NO7, the mean plane through the lactone-substituted ring of the pyrrolizidine moiety forms dihedral angles of 78.46 (6 and 58.28 (8° with the acenaphthylene moiety and the sugar based-lactone ring, respectively. The sum of the angles at the the N atom of the pyrrolizidine ring (335.0° is in accordance with sp3 hybridization. Some atoms of the acetate group are disordered and were refined using a split model [occupancy ratio 0.673 (10:0.327 (10].

Di-n-butyl 4,4′-dihydroxy-3,3′-{[(3aRS,7aRS-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene}dibenzoate

Directory of Open Access Journals (Sweden)

Augusto Rivera

2011-09-01

Full Text Available The complete molecule of the title compound, C31H42N2O6, is generated by crystallographic twofold symmetry, with one C atom lying on the axis. The dihedral angle between the aromatic rings is 57.03 (6°. The central heterocyclic ring adopts a half-chair conformation. The molecular conformation is stabilized by two intramolecular O—H...N hydrogen bonds with the N atoms of the heterocyclic ring as the acceptors. In the crystal, molecules are linked into chains along the c axis by non-classical C—H...O hydrogen bonds.

Interactive orbit control package for INDUS-2 storage ring

International Nuclear Information System (INIS)

Walia, A.A.S.; Ghodke, A.D.; Fatnani, Pravin; Bhujle, A.G.; Singh, Gurnam

2003-01-01

Maintaining the proper electron beam orbit is very important for all light sources. This package designed in Meatball provides for orbit control by just drag and drop. Simulation of Indus-2 storage ring in this package makes it useful for beam dynamic studies as well. Package functionality and architecture is described. (author)

Interactive orbit control package for INDUS-2 storage ring

Energy Technology Data Exchange (ETDEWEB)

Walia, A A.S.; Ghodke, A D; Fatnani, Pravin; Bhujle, A G; Singh, Gurnam [Centre for Advanced Technology, Indore (India)

2003-07-01

Maintaining the proper electron beam orbit is very important for all light sources. This package designed in Meatball provides for orbit control by just drag and drop. Simulation of Indus-2 storage ring in this package makes it useful for beam dynamic studies as well. Package functionality and architecture is described. (author)

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...

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

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.

How to make a tree ring: Coupling stem water flow and cambial activity in mature Alpine conifers

Science.gov (United States)

Peters, Richard L.; Frank, David C.; Treydte, Kerstin; Steppe, Kathy; Kahmen, Ansgar; Fonti, Patrick

2017-04-01

Inter-annual tree-ring measurements are used to understand tree-growth responses to climatic variability and reconstruct past climate conditions. In parallel, mechanistic models use experimentally defined plant-atmosphere interactions to explain past growth responses and predict future environmental impact on forest productivity. Yet, substantial inconsistencies within mechanistic model ensembles and mismatches with empirical data indicate that significant progress is still needed to understand the processes occurring at an intra-annual resolution that drive annual growth. However, challenges arise due to i) few datasets describing climatic responses of high-resolution physiological processes over longer time-scales, ii) uncertainties on the main mechanistic process limiting radial stem growth and iii) complex interactions between multiple environmental factors which obscure detection of the main stem growth driver, generating a gap between our understanding of intra- and inter-annual growth mechanisms. We attempt to bridge the gap between inter-annual tree-ring width and sub-daily radial stem-growth and provide a mechanistic perspective on how environmental conditions affect physiological processes that shape tree rings in conifers. We combine sub-hourly sap flow and point dendrometer measurements performed on mature Alpine conifers (Larix decidua) into an individual-based mechanistic tree-growth model to simulate sub-hourly cambial activity. The monitored trees are located along a high elevational transect in the Swiss Alps (Lötschental) to analyse the effect of increasing temperature. The model quantifies internal tree hydraulic pathways that regulate the turgidity within the cambial zone and induce cell enlargement for radial growth. The simulations are validated against intra-annual growth patterns derived from xylogenesis data and anatomical analyses. Our efforts advance the process-based understanding of how climate shapes the annual tree-ring structures

Crystal structure of (E-3-(2,4-dimethoxyphenyl-1-(1-hydroxynaphthalen-2-ylprop-2-en-1-one

Directory of Open Access Journals (Sweden)

Dongsoo Koh

2014-09-01

Full Text Available In the title compound, C21H18O4, the C=C bond of the central enone group adopts an E conformation. The dihedral angle formed by the benzene ring and the naphthalene ring system is 6.60 (2°. The methoxy groups on the benzene ring are essentially coplanar with the ring; the C—C—O—C torsion angles being 1.6 (2 and −177.1 (1°. The hydroxy group attached to the naphthalene ring is involved in an intramolecular O—H...O hydrogen bond. The relative conformation of the two double bonds in the enone group is s-cisoid. In the crystal, weak C—H...O hydrogen bonds link the molecules into chains propagating along [010].

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

Crystal structure of (E-4,4,4-trifluoro-3-phenylbut-2-enoic acid

Directory of Open Access Journals (Sweden)

Alexey Barkov

2015-12-01

Full Text Available In the title compound, C10H7F3O2, the dihedral angle between the benzene ring and the ethylene plane is 76.34 (11°. In the crystal, O—H...O hydrogen bonds link the molecules into C(4 chains propagating in [010].

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.

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.

(E-2-Methyl-6-{[(5-methylpyridin-2-ylimino]methyl}phenol

Directory of Open Access Journals (Sweden)

Md. Azharul Arafath

2017-01-01

Full Text Available In the title compound, C14H14N2O, the dihedral angle between the aromatic rings is 5.54 (9°. The conformation is reinforced by an intramolecular O—H...N hydrogen bond, which closes an S(6 ring. The pyridine N atom and methyl group lie to opposite sides of the molecule. In the crystal, the molecules are linked into a zigzag chain propagating in [0-11] by weak C—H...O hydrogen bonds.

9-Benzyl-6-benzylsulfanyl-9H-purin-2-amine

Directory of Open Access Journals (Sweden)

Maywan Hariono

2014-03-01

Full Text Available In the title compound, C19H17N5S, the dihedral angles between the purine ring system (r.m.s. deviation = 0.009 Å and the S-bound and methylene-bound phenyl rings are 74.67 (8 and 71.28 (7°, respectively. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate R22(8 loops. C—H...N interactions link the dimers into (100 sheets.

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

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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].

6,8-Dibromoquinoline

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Ísmail Çelik

2010-11-01

Full Text Available The title molecule, C9H5Br2N, is almost planar, with an r.m.s. deviation of 0.027 Å. The dihedral angle between the aromatic rings is 1.5 (3°. In the crystal, π–π stacking interactions are present between the pyridine and benzene rings of adjacent molecules [centroid–centroid distances = 3.634 (4 Å], and short Br...Br contacts [3.4443 (13 Å] occur.

4-Methyl-N-(4-nitrobenzoylbenzenesulfonamide

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P. A. Suchetan

2011-04-01

Full Text Available In title compound, C14H12N2O5S, the dihedral angle between the sulfonyl benzene ring and the —SO2—NH—C—O segment is 81.5 (2° and that between the sulfonyl and the benzoyl benzene rings is 89.8 (1°. In the crystal, molecules are linked into chains along the b axis via intermolecular N—H...O hydrogen bonds. C—H...O interactions are also observed.

N-(2,6-Dichlorophenyl-4-methylbenzamide

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Vinola Z. Rodrigues

2011-08-01

Full Text Available In the title compound, C14H11Cl2NO, the two aromatic rings are nearly orthogonal to each other [dihedral angle 79.7 (1°], while the central amide core –NH—C(=O– is nearly coplanar with the benzoyl ring [N—C—C—C torsion angles = −5.5 (3 and 1772. (2°]. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(4 chains propagating in [001].

Theoretical model to the Raman spectrum of B2O3

International Nuclear Information System (INIS)

Barrio, R.A.

1984-01-01

In this paper we report a new theory that reproduces qualitatively well the Raman spectrum of v-B 2 O 3 . The basic idea is that one can find the thermodinamically averaged Green's function for a Bethe lattice, with a Born Hamiltonian, with dihedral angles totally random. In extension one constructs a Bethe lattice of rings and solve the equations of motion for Green's functions at the Boron sites, bridging oxygens and oxygens in the rings. (M.W.O.) [pt

4-Hydroxy-3-[(2E-3-(3,4,5-trimethoxyphenylprop-2-enoyl]-2H-chromen-2-one

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Lassaad Mechi

2009-07-01

Full Text Available A new chalcone of the coumarin, C21H18O7, containing an annulated α-pyrone ring, was obtained by condensation of the borate complex of acyl(hydroxycoumarin with trimethoxybenzaldehyde. The structure exhibits intramolecular hydrogen bonding between the hydroxyl oxygen and the ketonic oxygen in the coumarin group. The bicyclic coumarin fragment and the benzene ring form a dihedral angle of 17.1 (4°. The crystal packing involves dimers interconnected by C—H...O hydrogen bonding.

Methyl 4′,5-dichloro-2-hydroxy-4,6-dimethylbiphenyl-3-carboxylate

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Muhammad Adeel

2012-04-01

Full Text Available In the title compound, C16H14Cl2O3, the dihedral angle between the mean planes of the two benzene rings is 55.30 (5°. The methyl ester group lies within the ring plane due to an intramolecular O—H...O hydrogen bond [maximum deviation from the C8O2 mean plane is 0.0383 (13 Å]. In the crystal, molecules are held together by rather weak C—H...O hydrogen bonds.

2,5-Bis{2,2-bis[4-(dimethylaminophenyl]ethenyl}-N,N′-diphenyl-N,N′-dipropylbenzene-1,4-diamine

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Volker Schmitt

2011-04-01

Full Text Available The title compound, C60H68N6, was prepared by Horner olefination of a terephthaldialdehyde and a diarylmethyl phosphonate. There is one half-molecule, located on an inversion centre, in the asymmetric unit. The dihedral angle between the plane of the vinylene unit and the central ring is 36.79 (15°, while those between the vinylene unit and the lateral phenyl rings are 53.04 (10 and 53.74 (9°.

Dimethyl 5,5′-methylenebis(2-hydroxybenzoate

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Artur M. S. Silva

2012-05-01

Full Text Available In the title compound, C17H16O6, the two methyl salicylate moieties are related by crystallographic twofold rotational symmetry with the two benzene rings close to being perpendicular [inter-ring dihedral angle = 86.6 (8°]. Intramolecular phenolic O—H...O hydrogen bonds with carboxyl O-atom acceptors are present, with these groups also involved in centrosymmetric cyclic intermolecular O—H...O hydrogen-bonding associations [graph set R22(4], giving infinite chains extending across (101.

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.

CIRS High-Resolution Thermal Scans and the Structure of Saturn's B Ring

Science.gov (United States)

Brooks, S. M.; Spilker, L. J.; Showalter, M.; Pilorz, S.; Edgington, S. G.

2017-12-01

The flyby of Titan on November 29, 2016, sent the Cassini spacecraft on a trajectory that would take it within 10,000 kilometers of Saturn's F ring multiple times before a subsequent Titan encounter on April 22, 2017, would send it on ballistic trajectory carrying it between Saturn's cloud tops and the planet's D ring for several flybys. This geometry has proven beneficial for high-resolution studies of the rings, not just because of Cassini's proximity to the rings, but also because of the spacecraft's high elevation angle above the rings, which reduces the foreshortening that tends to degrade resolution in the ring plane. We will report on several observations of Saturn's main rings at the high spatial resolutions enabled by the end-of-mission geometry, particulary the B ring, with the Composite Infrared Spectrometer onboard Cassini during the F-ring and proximal orbits. CIRS' three infrared detectors cover a combined spectral range of 10 to 1400 cm-1 (1 mm down to 7 microns). We focus on data from Focal Plane 1, which covers the 10 to 600 cm-1 range (1 mm to 16 microns). The apodized spectral resolution of the instrument can be varied from 15 cm-1 to 0.5 cm-1 (Flasar et al. 2004). FP1's wavelength range makes it well-suited to sensing thermal emission from objects at temperatures typical of Saturn's rings. Correlating ring optical depth with temperatures retrieved from scans of the face of the rings exposed to direct solar illumination (the lit face) and the opposite (unlit) face suggests differences in ring structure or particle transport between the lit and unlit sides of the rings in different regions of the B ring. Lit side temperatures in the core of the B ring range between 82 and 87 K; temperatures on the unlit side of the core vary from 66 K up to 74 K. Ferrari and Reffet (2013) and Pilorz et al. (2015) published thorough analyses of the thermal throughput across this optically thick ring. We will discuss these recent CIRS rings observations and their

Alpha - Skew Pi - Armendariz Rings

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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.

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

On the compressor ring for the JAERI neutron science project

Energy Technology Data Exchange (ETDEWEB)

Yamane, Isao [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1997-11-01

(1), As long as a 1.5 GeV-8 MW linear accelerator is constructed in the JAERI neutron science center, it is quite reasonable to construct a 5 MW compressor ring as a driver of a high intensity spallation neutron source to generate pulsed neutron beams. (2), Suppression of beam loss around the compressor ring to an acceptable level is the most crucial subject to be coped with in designing a MW-class compressor ring. This subject should be successfully cleared by carefully studying and designing the overall system of accelerator and tunnel. (3), The `PSR instability` was comprehensively discussed in the NSNS workshop held at Santa Fe in March, 1997, as a remaining problem of a high intensity proton compressor ring. People of Los Alamos attributed it to an e-p instability. But some questions like the cause that makes some part of protons leak away from a beam bunch to a bunch gap are yet left open. (4), A new scheme of two step H{sup 0} injection is proposed to remove defects of the conventional one of Los Alamos PSR. (author)

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....

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

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...

Ring artifact reduction in synchrotron X-ray tomography through helical acquisition

NARCIS (Netherlands)

D.M. Pelt (Daniël); D.Y. Parkinson (Dilworth)

2017-01-01

textabstractIn synchrotron X-ray tomography, systematic defects in certain detector elements can result in arc-shaped artifacts in the final reconstructed image of the scanned sample. These ring artifacts are commonly found in many applications of synchrotron tomography, and can make

Improving the accuracy of Laplacian estimation with novel multipolar concentric ring electrodes

Science.gov (United States)

Ding, Quan; Besio, Walter G.

2015-01-01

Conventional electroencephalography with disc electrodes has major drawbacks including poor spatial resolution, selectivity and low signal-to-noise ratio that are critically limiting its use. Concentric ring electrodes, consisting of several elements including the central disc and a number of concentric rings, are a promising alternative with potential to improve all of the aforementioned aspects significantly. In our previous work, the tripolar concentric ring electrode was successfully used in a wide range of applications demonstrating its superiority to conventional disc electrode, in particular, in accuracy of Laplacian estimation. This paper takes the next step toward further improving the Laplacian estimation with novel multipolar concentric ring electrodes by completing and validating 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 that allows cancellation of all the truncation terms up to the order of 2n. An explicit formula based on inversion of a square Vandermonde matrix is derived to make computation of multipolar Laplacian more efficient. To confirm the analytic result of the accuracy of Laplacian estimate increasing with the increase of n and to assess the significance of this gain in accuracy for practical applications finite element method model analysis has been performed. Multipolar concentric ring electrode configurations with n ranging from 1 ring (bipolar electrode configuration) to 6 rings (septapolar electrode configuration) were directly compared and obtained results suggest the significance of the increase in Laplacian accuracy caused by increase of n. PMID:26693200

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)

N′-[(E-3-Pyridylmethylidene]benzohydrazide

Directory of Open Access Journals (Sweden)

Liyuan Wen

2009-11-01

Full Text Available The title compound, C13H11N3O, was prepared by the reaction of benzohydrazide and nicotinaldehyde. The dihedral angle between the planes of the two aromatic rings is 47.78 (9°. The crystal structure is stabilized by intermolecular N—H...N hydrogen-bonding interactions.

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…

The 8-GeV transfer line injection into main ring

International Nuclear Information System (INIS)

Yang, M.J.

1995-06-01

Included in this report are a brief review of the design lattice of the 8-GeV beam transfer line and the Main Ring, the recent measurements on the 8-GeV line lattice function as well as that of the Main Ring at 8-GeV. The injection matching is a very important part of the MR operation. Mismatches such as energy, timing, or position are easily corrected because they cause oscillations which are visible on the Turn-By-Turn (TBT) TV monitor display. Mis-matches due to beta and dispersion functions are detected only by using the Flying Wire or by doing measurements during beam study. A new method which makes use of the available data from TBT hardware was used to obtain the beam phase space ellipse. Data taken from Main Ring at injection gives the beta function needed for transfer matching from 8-GeV line. The result of this measurement is also presented here

Optimisation of spontaneous four-wave mixing in a ring microcavity

Science.gov (United States)

Chuprina, I. N.; An, P. P.; Zubkova, E. G.; Kovalyuk, V. V.; Kalachev, A. A.; Gol'tsman, G. N.

2017-11-01

A theory of spontaneous four-wave mixing in a ring microcavity is developed. The rate of emission of biphotons for pulsed and monochromatic pumping with allowance for the dispersion of group velocities is analytically calculated. In the first case, pulses in the form of an increasing exponential are considered, which are optimal for excitation of an individual resonator mode. The behaviour of the group velocity dispersion as a function of the width and height of the waveguide is studied for a specific case of a ring microcavity made of silicon nitride. The results of the numerical calculation are in good agreement with the experimental data. The ring microcavity is made of two types of waveguides: completely etched and half etched. It is found that the latter allow for better control over the parameters in the manufacturing process, making them more predictable. Presented at the Russian - British Symposium on Quantum Technologies (Moscow, 20 - 23 March 2017)

The impact of exospheric neutral dynamics on ring current decay

Science.gov (United States)

Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.

2015-12-01

The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.

3-[2-(1,3-Benzothiazol-2-ylsulfanylethyl]-1,3-oxazolidin-2-one

Directory of Open Access Journals (Sweden)

Yong-Hong Wen

2010-10-01

Full Text Available The title compound, C12H12N2S2O2, consists of a benzothiazole group and a oxazolidin-1-one linked via a flexible ethane-1,2-diyl spacer. The benzothiazole group and the oxazolidine ring are each almost planar [with maximum deviations of 0.007 (2 and 0.044 (3 Å, respectively] and make a dihedral angle of 9.35 (10°. In the crystal structure, adjacent molecules were connected through C—H...O and C—H...N hydrogen bonds, and further extended into a three-dimensional network structure through intermolecular aromatic π–π stacking interactions in which the centroid–centroid distance is 3.590 (1 Å.

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.

Primary Lung Signet Ring Cell Carcinoma Presenting as a Cavitary Pancoast Tumor in a 32-Year-Old Man.

Science.gov (United States)

Corvini, Michael; Koorji, Alysha; Sgroe, Erica; Nguyen, Uyen

2018-06-01

Signet ring cell carcinoma, a subtype of adenocarcinoma, is a rare cause of primary lung cancer. The authors report a case of primary lung signet ring cell carcinoma presenting as a cavitary Pancoast tumor in a 32-year-old male smoker. Beyond the rarity of primary lung signet ring cell carcinoma itself, the youth of the patient, his smoking status, the presence of cavitation, and the location of the tumor in the superior sulcus make it especially atypical.

Crystal structure of [1,1':3',1''-ter-phenyl]-2',3,3''-tri-carb-oxy-lic acid.

Science.gov (United States)

Decato, Daniel A; Berryman, Orion B

2015-09-01

The asymmetric unit of the title compound, C21H14O6, com-prises two symmetrically independent mol-ecules that form a locally centrosymmetric hydrogen-bonded dimer, with the planes of the corresponding carb-oxy-lic acid groups rotated by 15.8 (1) and 17.5 (1)° relative to those of the adjacent benzene rings. The crystal as a whole, however, exhibits a noncentrosymmetric packing, described by the polar space group Pca21. The dimers form layers along the ab plane, being inter-connected by hydrogen bonds involving the remaining carb-oxy-lic acid groups. The plane of the central carb-oxy-lic acid group forms dihedral angles of 62.5 (1) and 63.0 (1)° with those of the adjacent benzene rings and functions as a hydrogen-bond donor and acceptor. As a donor, it inter-connects adjacent layers, while as an acceptor it stabilizes the packing within the layers. The 'distal' carb-oxy-lic acid groups are nearly coplanar with the planes of the adjacent benzene rings, forming dihedral angles of 1.8 (1) and 7.1 (1)°. These groups also form intra- and inter-layer hydrogen bonds, but with 'reversed' functionality, as compared with the central carb-oxy-lic acid groups.

Crystal structure of [1,1′:3′,1′′-terphenyl]-2′,3,3′′-tricarboxylic acid

Directory of Open Access Journals (Sweden)

Daniel A. Decato

2015-09-01

Full Text Available The asymmetric unit of the title compound, C21H14O6, comprises two symmetrically independent molecules that form a locally centrosymmetric hydrogen-bonded dimer, with the planes of the corresponding carboxylic acid groups rotated by 15.8 (1 and 17.5 (1° relative to those of the adjacent benzene rings. The crystal as a whole, however, exhibits a noncentrosymmetric packing, described by the polar space group Pca21. The dimers form layers along the ab plane, being interconnected by hydrogen bonds involving the remaining carboxylic acid groups. The plane of the central carboxylic acid group forms dihedral angles of 62.5 (1 and 63.0 (1° with those of the adjacent benzene rings and functions as a hydrogen-bond donor and acceptor. As a donor, it interconnects adjacent layers, while as an acceptor it stabilizes the packing within the layers. The `distal' carboxylic acid groups are nearly coplanar with the planes of the adjacent benzene rings, forming dihedral angles of 1.8 (1 and 7.1 (1°. These groups also form intra- and inter-layer hydrogen bonds, but with `reversed' functionality, as compared with the central carboxylic acid groups.

2-(5,6-Diphenyl-1,2,4-triazin-3-ylaniline

Directory of Open Access Journals (Sweden)

Mariusz Mojzych

2012-12-01

Full Text Available The title compound, C21H16N4, obtained under standard Suzuki cross-coupling conditions, is a model compound in the synthesis and biological activity evaluation of new aza-analogues of sildenafil containing a pyrazolo[4,3-e][1,2,4]triazine system. An N—H...N intramolecular hydrogen bond involving the aminobenzene system and the 1,2,4-triazine moiety helps to establish a near coplanar orientation of the rings with a dihedral angle of 12.04 (4°, which is believed to be necessary for the biological activity of sildenafil analogues. The 1,2,4-triazine ring is slightly distorted from planarity [r.m.s deviation = 0.0299 (11 Å] and forms dihedral angles of 58.60 (4 and 36.35 (3° with the pendant phenyl rings. The crystal packing features bifurcated N—H...(N,N hydrogen bonds linking screw-axis-related molecules into chains parallel to the [010] direction< and π–π interactions, with a centroid–centroid separation of 3.8722 (7 Å and a slippage of 1.412 (3 Å. The crystal studied was a nonmerohedral twin with a ratio of 0.707 (2:0293 (2.

Crystal structure of trans-diaquabis(4-cyanobenzoato-κObis(N,N-diethylnicotinamide-κNcadmium

Directory of Open Access Journals (Sweden)

Nurcan Akduran

2016-12-01

Full Text Available The mononuclear title cadmium complex, [Cd(C10H14N2O2(C8H4NO22(H2O2], is centrosymmetric and contains two water molecules, two 4-cyanobenzoate (CB ligands and two diethylnicotinamide (DENA ligands. All the ligands are coordinated to the CdII atom in a monodentate mode. The four nearest O atoms around the CdII atom form a slightly distorted square-planar arrangement, with the distorted octahedral coordination sphere being completed by the two pyridine N atoms of the DENA ligands at distances of 2.3336 (13 Å. The dihedral angle between the carboxylate group and the adjacent benzene ring is 8.75 (16°, while the benzene and pyridine rings are oriented at a dihedral angle of 57.83 (5°. The water molecules exhibit both intramolecular [to the non-coordinating carboxylate O atom, enclosing an S(6 hydrogen-bonding motif, where O...O = 2.670 (2 Å] and intermolecular [to the amide carbonyl O atom, enclosing an R22(16 ring motif, where O...O = 2.781 (2 Å] O—H...O hydrogen bonds. The latter lead to the formation of supramolecular chains propagating along [110].

Contradiction between the results of observations of resistance and critical current quantum oscillations in asymmetric superconducting rings

International Nuclear Information System (INIS)