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

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-01

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

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.)

Difference between ²JC2H3 and ²JC3H2 spin-spin couplings in heterocyclic five- and six-membered rings as a probe for studying σ-ring currents: a quantum chemical analysis.

Science.gov (United States)

Contreras, Rubén H; dos Santos, Francisco P; Ducati, Lucas C; Tormena, Cláudio F

2010-12-01

Adequate analyses of canonical molecular orbitals (CMOs) can provide rather detailed information on the importance of different σ-Fermi contact (FC) coupling pathways (FC term transmitted through the σ-skeleton). Knowledge of the spatial distribution of CMOs is obtained by expanding them in terms of natural bond orbitals (NBOs). Their relative importance for transmitting the σ-FC contribution to a given spin-spin coupling constants (SSCCs) is estimated by resorting to the expression of the FC term given by the polarisation propagator formalism. In this way, it is possible to classify the effects affecting such couplings in two different ways: delocalisation interactions taking place in the neighbourhood of the coupling nuclei and 'round the ring' effects. The latter, associated with σ-ring currents, are observed to yield significant differences between the FC terms of (2)J(C2H3) and (2)J(C3H2) SSCCs which, consequently, are taken as probes to gauge the differences in σ-ring currents for the five-membered rings (furan, thiophene, selenophene and pyrrol) and also for the six-membered rings (benzene, pyridine, protonated pyridine and N-oxide pyridine) used in the present study. Copyright © 2010 John Wiley & Sons, Ltd.

Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives

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Malwina Krause

2017-03-01

Full Text Available The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABAA receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines reported from the year 2000 to date, including structure–activity relationships.

Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives.

Science.gov (United States)

Krause, Malwina; Foks, Henryk; Gobis, Katarzyna

2017-03-04

The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABA A receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5- b ]pyridines and imidazo[4,5- c ]pyridines reported from the year 2000 to date, including structure-activity relationships.

Proton storage ring: man/machine interface

International Nuclear Information System (INIS)

Lander, R.F.; Clout, P.N.

1985-01-01

The human interface of the Proton Storage Ring Control System at Los Alamos is described in some detail, together with the software environment in which operator interaction programs are written. Some examples of operator interaction programs are given

Transformation of Zwitterionic Pyridine Derivatives to a Spiro-Fused Ring System: Azoniabenzo[de]fluorine. Synthesis and Mechanistic Rationalization.

Science.gov (United States)

Palkó, Roberta; Egyed, Orsolya; Rokob, Tibor András; Bombicz, Petra; Riedl, Zsuzsanna; Hajós, György

2015-01-02

Reaction of aryl- and benzylsulfanopyridinium amidates bearing a methyl group in position 6 with 2 equiv of diphenylketene afforded a spiro-fused ring system: azoniabenzo[de]fluorine. By use of an excess amount of ketene, a distinct reaction was observed via which a 1H-pyrrolo[3,2-b]pyridin-2(3H)-one derivative was furnished. The structure of the tetracyclic spiro-fused ring system was unambiguously confirmed by X-ray diffraction, and its formation was rationalized by DFT calculations.

The physics interests of a 10 TeV proton synchrotron, 400 x 400 GeV2 proton storage rings, and electron-proton storage rings

International Nuclear Information System (INIS)

Camilleri, L.

1976-01-01

This report consists of a collection of documents produced by two Study Groups, one on a multi-TeV Proton Synchrotron and the other on 400 x 400 GeV 2 Proton Storage Rings. In both studies the reactions of interest in the weak, electromagnetic and strong interactions are discussed. The technical feasibility of the relevant experiments is investigated by attempting. in each case, the design of an experimental set-up. Event rates are estimated using currently p revailing theoretical models and by extrapolation of results at present accelerators. In addition to the work of the two Study Groups, a section on the physics interests and technical problems of ep Storage Rings is included. (author)

2-[5-(Pyridin-2-yl-1,3,4-thiadiazol-2-yl]pyridin-1-ium perchlorate

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Abdelhakim Laachir

2017-03-01

Full Text Available The cation of the title molecular salt, C12H9N4S+·ClO4−, is approximately planar, with the pyridine and pyridinium rings being inclined to the central thiadiazole ring by 6.51 (9 and 9.13 (9°, respectively. The dihedral angle between the pyridine and pyridinium rings is 12.91 (10°. In the crystal, the cations are linked by N—H...O and C—H...O hydrogen bonds, involving the perchlorate anion, forming chains propagating along the [100] direction. The chains are linked by weak offset π–π interactions [inter-centroid distance = 3.586 (1 Å], forming layers parallel to the ab plane.

On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

Energy Technology Data Exchange (ETDEWEB)

Navarrete-Encina, Patricio A.; Vega-Retter, Christian, E-mail: pnavarre@vtr.ne [Universidad de Chile, Santiago (Chile). Facultad de Ciencias Quimicas y Farmaceuticas. Lab. de Sintesis Organica y Fisicoquimica; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J. [Universidad de Chile, Santiago (Chile). Fac. de Ciencias Quimicas y Farmaceuticas. Lab. de Bioelectroquimica

2010-07-01

Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

International Nuclear Information System (INIS)

Navarrete-Encina, Patricio A.; Vega-Retter, Christian; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J.

2010-01-01

Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

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.

Proton storage ring summer workshop

International Nuclear Information System (INIS)

Lawrence, G.P.; Cooper, R.K.

1977-10-01

During the week of August 16, 1976 a Workshop was held at the Los Alamos Scientific Laboratory (LASL) on the Proton Storage Ring (PSR) for the Weapons Neutron Research Facility (WNRF). Written contributions were solicited from each of the participants in the Workshop, and the contributions that were received are presented. The papers do not represent polished or necessarily complete work, but rather represent ''first cuts'' at their respective areas. Topics covered include: (1) background information on the storage ring; (2) WNRF design; (3) rf transient during filling; (4) rf capture; (5) beam bunch compression; (6) transverse space charge limits; (7) transverse resistive instability in the PSR; (8) longitudinal resistive instability; (9) synchrotron frequency splitting; (10) E Quintus Unum--off resonance; (11) first harmonic bunching in the storage ring; (12) kicker considerations; (13) beam extraction; (14) ferrite kicker magnets; and (15) E Quintus Unum: a possible ejection scheme

(He 1) photoelectron spectra of vinyl- and (1-dimethylaminovinyl)pyridines

International Nuclear Information System (INIS)

Baidin, V.N.; Koikov, L.N.; Terent'ev, P.B.; Gloriozov, I.P.

1985-01-01

The (He 1) photoelectron spectra of α=, β-, γ-vinyl, α-, β-, and γ-(1-dimethylvinyl)-pyridines, 1-dimethyl- and 1-diethylaminostyrenes were obtained and interpreted within the framework of the molecular orbital perturbation theory. In both pyridine derivative series, there is a regular increase in the ionization energy of the 1α 2 , π/sub C=C/ and n/sub en/ orbitals and decrease in the ionization energy of the 2b 1 orbitals in the order α 2 and 2b 1 is found for γ-vinylpyridine). The splitting of the energy levels of the heterocycle in dimethylaminovinylpyridines is less than in the corresponding vinyl derivatives, which indicates a weakening of the interaction between the aromatic (or heteroaromatic) ring and the enamine fragment extruding from the ring plane. The ionization energy of the unshared electron pair of the nitrogen atom of the pyridine ring for all the compounds except for α- (1-dimethylaminovinyl)pyridine (which displays an ortho effect) is close to that for pyridine. The photoelectron spectral data are compared with the MO energies calculated by the MINDO/3 method

Theoretical study of hydrogen storage in a truncated triangular pyramid molecule consisting of pyridine and benzene rings bridged by vinylene groups

Science.gov (United States)

Ishikawa, Shigeru; Nemoto, Tetsushi; Yamabe, Tokio

2018-06-01

Hydrogen storage in a truncated triangular pyramid molecule C33H21N3, which consists of three pyridine rings and one benzene ring bridged by six vinylene groups, is studied by quantum chemical methods. The molecule is derived by substituting three benzene rings in a truncated tetrahedron hydrocarbon C36H24 with pyridine rings. The optimized molecular structure under C 3v symmetry shows no imaginary vibrational modes at the B3LYP/cc-pVTZ level of theory. The hydrogen storage process is investigated based on the MP2/cc-pVTZ method. Like the structure before substitution, the C33H21N3 molecule has a cavity that stores a hydrogen molecule with a binding energy of - 140 meV. The Langmuir isotherm shows that this cavity can store hydrogen at higher temperatures and lower pressures than usual physisorption materials. The C33H21N3 molecule has a kinetic advantage over the C36H24 molecule because the former molecule has a lower barrier (+ 560 meV) for the hydrogen molecule entering the cavity compared with the latter molecule (+ 730 meV) owing to the lack of hydrogen atoms narrowing the opening.

Selectively catalytic activity of metal–organic frameworks depending on the N-position within the pyridine ring of their building blocks

Energy Technology Data Exchange (ETDEWEB)

Xu, Haitao, E-mail: xuhaitao@ecust.edu.cn [School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Gou, Yongxia; Ye, Jing; Xu, Zhen-liang [School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Wang, Zixuan [School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2016-05-15

Iron metal–organic frameworks (MOFs) [Fe(L){sub 2}(SCN){sub 2}]{sub ∝} (L1: 4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene for 1Fe; and L2: 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene for 2Fe) were assembled in a MeOH–H{sub 2}O solvent system. 1Fe exhibits a two-dimensional extended-grid network, whereas 2Fe exhibits a stair-like double-chain; the N-position within the pyridine ring of the complexes was observed to regulate the MOF structure as layers or chains. Furthermore, selectively catalytic activity was observed for the layered MOF but not the chain-structured MOF; micro/nanoparticles of the layered MOF were therefore investigated for new potential applications of micro/nano MOFs. - Graphical abstract: Iron metal–organic frameworks (MOFs) [Fe(L){sub 2}(SCN){sub 2}]{sub ∝} (L1: 4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene for 1Fe; and L2: 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene for 2Fe) were assembled in a MeOH–H{sub 2}O solvent system. The N-position within the pyridine ring of the complexes was observed to regulate the MOF structure as layers or chains. Selectively catalytic activity was observed for the layered MOF but not the chain-structured MOF. - Highlights: • Synthesis and structure of metal–organic framework [Fe(L){sub 2}(SCN){sub 2}]{sub ∝}. • Selectively catalytic activity depending on the N-position within the pyridine ring. • The degradation and conversion of methyl orange.

Selectively catalytic activity of metal–organic frameworks depending on the N-position within the pyridine ring of their building blocks

International Nuclear Information System (INIS)

Xu, Haitao; Gou, Yongxia; Ye, Jing; Xu, Zhen-liang; Wang, Zixuan

2016-01-01

Iron metal–organic frameworks (MOFs) [Fe(L) 2 (SCN) 2 ] ∝ (L1: 4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene for 1Fe; and L2: 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene for 2Fe) were assembled in a MeOH–H 2 O solvent system. 1Fe exhibits a two-dimensional extended-grid network, whereas 2Fe exhibits a stair-like double-chain; the N-position within the pyridine ring of the complexes was observed to regulate the MOF structure as layers or chains. Furthermore, selectively catalytic activity was observed for the layered MOF but not the chain-structured MOF; micro/nanoparticles of the layered MOF were therefore investigated for new potential applications of micro/nano MOFs. - Graphical abstract: Iron metal–organic frameworks (MOFs) [Fe(L) 2 (SCN) 2 ] ∝ (L1: 4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene for 1Fe; and L2: 3-bpdh=2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene for 2Fe) were assembled in a MeOH–H 2 O solvent system. The N-position within the pyridine ring of the complexes was observed to regulate the MOF structure as layers or chains. Selectively catalytic activity was observed for the layered MOF but not the chain-structured MOF. - Highlights: • Synthesis and structure of metal–organic framework [Fe(L) 2 (SCN) 2 ] ∝ . • Selectively catalytic activity depending on the N-position within the pyridine ring. • The degradation and conversion of methyl orange.

Pulsed Power Applications in High Intensity Proton Rings

CERN Document Server

Zhang, Wu; Ducimetière, Laurent; Fowler, Tony; Kawakubo, Tadamichi; Mertens, Volker; Sandberg, Jon; Shirakabe, Yoshihisa

2005-01-01

The pulsed power technology has been applied in particle accelerators and storage rings for over four decades. It is most commonly used in injection, extraction, beam manipulation, source, and focusing systems. These systems belong to the class of repetitive pulsed power. In this presentation, we review and discuss the history, present status, and future challenge of pulsed power applications in high intensity proton accelerators and storage rings.

MeV proton flux predictions near Saturn's D ring.

Science.gov (United States)

Kollmann, P; Roussos, E; Kotova, A; Cooper, J F; Mitchell, D G; Krupp, N; Paranicas, C

2015-10-01

Radiation belts of MeV protons have been observed just outward of Saturn's main rings. During the final stages of the mission, the Cassini spacecraft will pass through the gap between the main rings and the planet. Based on how the known radiation belts of Saturn are formed, it is expected that MeV protons will be present in this gap and also bounce through the tenuous D ring right outside the gap. At least one model has suggested that the intensity of MeV protons near the planet could be much larger than in the known belts. We model this inner radiation belt using a technique developed earlier to understand Saturn's known radiation belts. We find that the inner belt is very different from the outer belts in the sense that its intensity is limited by the densities of the D ring and Saturn's upper atmosphere, not by radial diffusion and satellite absorption. The atmospheric density is relatively well constrained by EUV occultations. Based on that we predict an intensity in the gap region that is well below that of the known belts. It is more difficult to do the same for the region magnetically connected to the D ring since its density is poorly constrained. We find that the intensity in this region can be comparable to the known belts. Such intensities pose no hazard to the mission since Cassini would only experience these fluxes on timescales of minutes but might affect scientific measurements by decreasing the signal-to-contamination ratio of instruments.

Crystal structure of 2-hydroxyimino-2-(pyridin-2-yl-N′-[1-(pyridin-2-ylethylidene]acetohydrazide

Directory of Open Access Journals (Sweden)

Maxym O. Plutenko

2014-12-01

Full Text Available The molecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å, with the planes of the two pyridine rings inclined to one another by 5.51 (7°. The oxime group is syn to the amide group, probably due to the formation of an intramolecular N—H...N hydrogen bond that forms an S(6 ring motif. In the crystal, molecules are linked by pairs of bifurcated O—H...(O,N hydrogen bonds, forming inversion dimers. The latter are linked via C—H...O and C—H...N hydrogen bonds, forming sheets lying parallel to (502. The sheets are linked via π–π stacking interactions [inter-centroid distance = 3.7588 (9 Å], involving the pyridine rings of inversion-related molecules, forming a three-dimensional structure.

Storage ring proton EDM experiment

CERN Multimedia

CERN. Geneva

2015-01-01

sensitivity of 10^-29 e-cm.  The strength of the method originates from the fact that there are high intensity polarized proton beams available and the fact that the so-called geometric phase systematic error background cancels with clock-wise and counter-clock-wise storage possible in electric rings. The ultimate sensitivity of the method is 10^-30 e-cm. At this level it will either detect a non-zero EDM or it will eliminate electro-weak baryogenesis.

Planning and Prototyping for a Storage Ring Measurement of the Proton Electric Dipole Moment

Energy Technology Data Exchange (ETDEWEB)

Talman, Richard [Cornell Univ., Ithaca, NY (United States)

2015-07-01

Electron and proton EDM's can be measured in "frozen spin" (with the beam polarization always parallel to the orbit, for example) storage rings. For electrons the "magic" kinetic energy at which the beam can be frozen is 14.5 MeV. For protons the magic kinetic energy is 230 MeV. The currently measured upper limit for the electron EDM is much smaller than the proton EDM upper limit, which is very poorly known. Nevertheless, because the storage ring will be an order of magnitude cheaper, a sensible plan is to first build an all-electric electron storage ring as a prototype. Such an electron ring was successfully built at Brookhaven, in 1954, as a prototype for their AGS ring. This leaves little uncertainty concerning the cost and performance of such a ring. (This is documentedin one of the Physical Review papers mentioned above.)

Poly[propane-1,3-diammonium [cuprate(II-bis(μ2-pyridine-2,3-dicarboxylato] trihydrate

Directory of Open Access Journals (Sweden)

Shabnam Hooshmand

2008-02-01

Full Text Available The title polymeric compound {(C3H12N2[Cu(C7H3NO42]·3H2O}n or {(pnH2[Cu(py-2,3-dc2]·3H2O}n (pn is propane-1,3-diamine and py-2,3-dcH2 is pyridine-2,3-dicarboxylic acid, was synthesized by reaction of copper(II chloride dihydrate with a proton-transfer compound, propane-1,3-diammonium pyridine-2,3-dicarboxylate or (pnH2(py-2,3-dc, in aqueous solution. The anion is a six-coordinate complex (site symmetry overline{1}, with a distorted octahedral geometry around CuII, consisting of two bidentate pyridine-2,3-dicarboxylate groups and two O atoms of bridging ligands from (py-2,3-dc2− fragments, which are located in trans positions. The (pnH22+ cation is disordered over two sites by the center of inversion. Intermolecular hydrogen bonds, π–π [centroid–centroid distances of 3.539 (3 Å] and C—O...π stacking interactions [O...Cg = 3.240 (5 Å; Cg is the center of the pyridine ring], connect the various components into a supramolecular structure.

Scaling in inelastic proton-proton interactions at storage ring energies of 23-63 GeV

International Nuclear Information System (INIS)

Thome, W.

1980-02-01

In this paper inelastic proton-proton interactions are studied with low transversal momenta ( approx. equal to 350 MeV/c) of the final state hadrons. The reaction products from p-p collisions have been detected for the first time visually, using two large streamer chambers which enclose one interaction region of the CERN storage rings almost completely. (orig./HSI) [de

Measuring proton beam thermal noises on the NAP-M storage ring

International Nuclear Information System (INIS)

Dement'ev, E.N.; Dikanskij, N.S.; Medvedko, A.S.; Parkhomchuk, V.V.; Pestrikov, D.V.

1980-01-01

The data on experimental investigation of thermal noises of an asimuthally homogeneous proton beam on the NAP-M storage ring are given. The noise spectra are measured at the 5th and 8th harmonics of the ciculation frequency using pick-up electrodes. The dependencies of the noise power on the proton current for noncooled and cooled beams are presented. It is shown that as a result of electron cooling the noise power decreases by two orders and in the 0.5-10 μA current range the noise power of the cooled beam does not depend on the proton current. The noise power of the noncooled beam linearly increases with the proton current. It is also shown that with the modulation growth the noise power increases. The conclusions are made that while analyzing noises of the continuous beam in the storage ring the changes of the noise spectra due to particle interaction in the beam should be taken into account

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

Directory of Open Access Journals (Sweden)

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].

Design for a second-generation proton storage ring at LAMPF

International Nuclear Information System (INIS)

Colton, E.P.

1988-01-01

A conceptual design is presented for a second-generation proton storage ring complex at LAMPF. The facility would consist of two stacked racetrack-shaped machines. These machines would deliver a 1.2-mA beam of 1.6-GeV protons at 48 Hz. The pulse length would be 1.75 μsec which represents a time compression of 570. 1 ref., 8 figs., 1 tab

2-Amino­benzoic acid–4-[2-(pyridin-4-yl)eth­yl]pyridine (2/1)

OpenAIRE

Arman, Hadi D.; Tiekink, Edward R. T.

2013-01-01

The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-yl)ethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6)°] despite the presence of an intramolecular N—H...O(carbonyl) hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl) hydrogen bonds, and these are connecte...

Radiation environment of proton accelerators and storage rings

Energy Technology Data Exchange (ETDEWEB)

Stevenson, G R

1976-03-08

These lecture notes survey the physical processes that give rise to the stray-radiation environment of proton synchrotrons and storage rings, with emphasis on their importance for radiation protection. The origins of the prompt radiation field (which disappears when the accelerator is switched off) are described in some detail: proton-nucleus interactions, extranuclear cascades, muon generation and transport. The effects of induced radioactivity in the accelerator structure and surroundings, notably in iron, concrete, air, and water, are discussed, and methods for monitoring hadrons in the radiation environment outside the accelerator are listed. Seventy-six references to the literature are included.

Crystal structure of 2-hy-droxy-imino-2-(pyridin-2-yl)-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.

Science.gov (United States)

Plutenko, Maxym O; Lampeka, Rostislav D; Haukka, Matti; Nordlander, Ebbe

2014-12-01

The mol-ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra-molecular N-H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of bifurcated O-H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π-π stacking inter-actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol-ecules, forming a three-dimensional structure.

2-Aminobenzoic acid–4-(pyridin-4-yldisulfanylpyridine (1/1

Directory of Open Access Journals (Sweden)

Hadi D. Arman

2011-12-01

Full Text Available The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanylpyridine molecule [dihedral angle between the pyridine rings = 89.06 (10°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O—H...N and N—H...N hydrogen bonds into a supramolecular chain along the b axis. These are connected into layers by π–π interactions occurring between pyridine rings [centroid–centroid distance = 3.8489 (15 Å]. The layers are connected along the a axis by C—H...O contacts. The crystal studied was a racemic twin.

Low energy current accumulator for high-energy proton rings

International Nuclear Information System (INIS)

Month, M.

1977-01-01

Building current in high-energy p-p colliding beam machines is most appropriately done in a low-energy (small circumference) current accumulator. Three significant factors favor such a procedure: First, large rings tend to be susceptible to unstable longitudinal density oscillations. These can be avoided by pumping up the beam in the accumulator. When the current stack is injected into the storage ring, potentially harmful instability is essentially neutralized. Second, high-field magnets characteristic of future high energy proton rings are designed with superconducting coils within the iron magnetic shield. This means coil construction and placement errors propagate rapidly within the beam aperture. An intermediate ''stacking ring'' allows the minimum use of the superconducting ring aperture. Finally, the coils are vulnerable to radiation heating and possible magnet quenching. By minimizing beam manipulaion in the superconducting environment and using only the central portion of the beam aperture, coil vulnerability can be put at a minimum

(3aS,7aS-5-[(S-3,3,3-Trifluoro-2-methoxy-2-phenylpropanoyl]-2,3,4,5,6,7-hexahydro-1H-pyrrolo[3,4-c]pyridin-3(2H-one monohydrate

Directory of Open Access Journals (Sweden)

Huichun Zhu

2010-01-01

Full Text Available rac-Benzyl 3-oxohexahydro-1H-pyrrolo[3,4-c]pyridine-5(6H-carboxylate was separated by chiral chromatography, and one of the enantiomers ([α]22D = +10° was hydrogenated in the presence of Pd/C in methanol, producing octahydro-3H-pyrrolo[3,4-c]pyridin-3-one. The latter was reacted with (2R-3,3,3-trifluoro-2-methoxy-2-phenylpropanoyl chloride [(R-(−-Mosher acid chloride], giving rise to the title compound, C17H19F3N2O3·H2O. The present structure established the absolute configuration of the pyrrolopiperidine fragment based on the known configuration of the (R-Mosher acid chloride. The piperidine ring has a somewhat distorted chair conformation and is cis-fused with the five-membered envelope-shaped ring; the plane of the exocyclic amide bond is approximately orthogonal to the plane of the phenyl ring, making a dihedral angle of 82.31 (3°. The water molecule acts as an acceptor to the proton of the amino group in an N—H...O interaction, and as a double proton donor in O—H...O hydrogen bonds, generating infinite bands along the a axis.

Theory of magnetospheric hydromagnetic waves excited by energetic ring-current protons

International Nuclear Information System (INIS)

Chen, Liu; Hasegawa, Akira.

1987-06-01

A general theoretical formulation, allowing finite ion Larmor radii, general magnetic field geometries and plasma equilibria, has been developed to investigate excitations of magnetohydrodynamic (MHD) Alfven waves within the earth's magnetosphere by the storm-time energetic ring-current protons. In particular, it is found that for adiabatically injected protons, various predicted instability properties are consistent with satellite observations. 8 refs

IKOR - An isochronous pulse compressor ring for proton beams

International Nuclear Information System (INIS)

Schaffer, G.

1981-06-01

This report contains the results of a study carried out for an isochronous compressor ring IKOR which compresses the 500 μs linac macropulses into pulses of 0.68 μs length. Its basic component is a ring magnet with alternating gradient and separated functions. Due to the isochronous operation, an rf system can be avoided which otherwise would be necessary in order to maintain a void in the circulating beam for the purpose of ejection. Injection is performed by charge exchange. The H - beam of the accelerator is first converted into a H 0 beam by stripping off one electron by a high gradient magnet placed in the transfer channel. Subsequently, the beam is converted into a proton beam by removing the remaining electron through a stripping foil in the ring. IKOR will be filled in 658 turns. Immediately after filling, the beam is ejected in a single turn via a kicker and a septum magnet and is transported to the spallation target. Because of the high intensity of 2.7 x 10 14 protons per pulse and, secondly, due to the high repetition rate of 100 Hz, beam dynamics and radiation protection aspects dominate the design and are, for this reason, treated in detail. (orig.)

CONSIDERATIONS ABOUT PROTON - NEUTRON INTERACTIONS IN THE INTERSECTING STORAGE RINGS

CERN Document Server

Bartl, W; Steuer, M; Hubner, K

1969-01-01

The pos'sibility of proton-neutron scattering experiments at the CERN Intersecting Storage Rings is studied. The use of proton-deuteron collisions to measure the reaction p+d •*• p*pv+n,witheitherp.orn,asspectator nucléon is discussed. An analysing magnet around the deuteron beamline allows to detect both nucléons of the deuteron up to the zero-momentum-transfer" région. Accélération and storage of deuteron beams is considered.

Electron cloud development in the Proton Storage Ring and in the Spallation Neutron Source

International Nuclear Information System (INIS)

Pivi, M.T.F.; Furman, M.A.

2002-01-01

We have applied our simulation code ''POSINST'' to evaluate the contribution to the growth rate of the electron-cloud instability in proton storage rings. Recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR) at Los Alamos are presented in this paper. A key ingredient in our model is a detailed description of the secondary emitted-electron energy spectrum. A refined model for the secondary emission process including the so-called true secondary, rediffused and backscattered electrons has recently been included in the electron-cloud code

Isomers and conformational barriers of gas phase nicotine, nornicotine and their protonated forms

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Tomoki; Farone, William A.; Xantheas, Sotiris S.

2014-07-17

We report extensive conformational searches of the neutral nicotine, nornicotine and their protonated analogs that are based on ab-initio second order Møller-Plesset perturbation (MP2) electronic structure calculations. Initial searches were performed with the 6-31G(d,p) and the energetics of the most important structures were further refined from geometry optimizations with the aug-cc-pVTZ basis set. Based on the calculated free energies at T=298 K for the gas phase molecules, neutral nicotine has two dominant trans conformers, whereas neutral nornicotine is a mixture of several conformers. For nicotine, the protonation on both the pyridine and the pyrrolidine sites is energetically competitive, whereas nornicotine prefers protonation on the pyridine nitrogen. The protonated form of nicotine is mainly a mixture of two pyridine-protonated trans conformers and two pyrrolidine-protonated trans conformers, whereas the protonated form of nornicotine is a mixture of four pyridine-protonated trans conformers. Nornicotine is conformationally more flexible than nicotine, however it is less protonated at the biologically important pyrrolidine nitrogen site. The lowest energy isomers for each case were found to interconvert via low (< 6 kcal/mol) rotational barriers around the pyridine-pyrrolidine bond.

Structure of fullerene aggregates in pyridine/water solutions by small-angle neutron scattering

International Nuclear Information System (INIS)

Aksenov, V.L.; Belushkin, A.V.; Avdeev, M.V.; Rosta, L.; Mihailovic, D.; Mrzel, A.; Serdyuk, I.N.; Timchenko, A.A.

2001-01-01

Results of small-angle neutron scattering experiments on fullerenes (C 60 ) in pyridine/water solutions are reported. They confirm conclusions of the previous studies, in particular, dynamic light scattering experiments. Aggregates with characteristic radius of about 20 nm are formed in the solutions. The contrast variation using different combinations of protonated/deuterated components (water and pyridine) of the solutions points to the small pyridine content inside the aggregates. This fact testifies that the aggregates consist of a massive fullerene core covered by a thin pyridine shell

The radiation environment of proton accelerators and storage rings

International Nuclear Information System (INIS)

Stevenson, G.R.

1976-01-01

These lecture notes survey the physical processes that give rise to the stray-radiation environment of proton synchrotrons and storage rings, with emphasis on their importance for radiation protection. The origins of the prompt radiation field (which disappears when the accelerator is switched off) are described in some detail: proton-nucleus interactions, extranuclear cascades, muon generation and transport. The effects of induced radioactivity in the accelerator structure and surroundings, notably in iron, concrete, air, and water, are discussed and methods for monitoring hadrons in the radiation environment outside the accelerator are listed. Seventy-six references to the literature are included. (Author)

2,3-Diamino-pyridinium 6-carb-oxy-pyridine-2-carboxyl-ate.

Science.gov (United States)

Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

2011-12-01

The asymmetric unit of the title proton-transfer compound, C(5)H(8)N(3) (+)·C(7)H(4)NO(4) (-), consists of one mono-deprotonated pyridine-2,6-dicarb-oxy-lic acid as anion and one protonated 2,3-diamino-pyridine as cation. The crystal packing shows extensive O-H⋯O, N-H⋯O and N-H⋯N hydrogen bonds. Thre are also several π-π inter-actions between the anions and also between the cations [centriod-centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å].

Crystal structure of 2-hy­droxy­imino-2-(pyridin-2-yl)-N′-[1-(pyridin-2-yl)ethyl­idene]acetohydrazide

Science.gov (United States)

Plutenko, Maxym O.; Lampeka, Rostislav D.; Haukka, Matti; Nordlander, Ebbe

2014-01-01

The mol­ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra­molecular N—H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol­ecules are linked by pairs of bifurcated O—H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C—H⋯O and C—H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π–π stacking inter­actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol­ecules, forming a three-dimensional structure. PMID:25552998

A storage ring experiment to detect a proton electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Anastassopoulos, V. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Andrianov, S. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T2A3, Canada; Baessler, S. [Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA; Bai, M. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Benante, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Berz, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Blaskiewicz, M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Bowcock, T. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Brown, K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Casey, B. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Conte, M. [Physics Department and INFN Section of Genoa, 16146 Genoa, Italy; Crnkovic, J. D. [Brookhaven National Laboratory, Upton, New York 11973, USA; D’Imperio, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fanourakis, G. [Institute of Nuclear and Particle Physics NCSR Demokritos, GR-15310 Aghia Paraskevi Athens, Greece; Fedotov, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fierlinger, P. [Technical University München, Physikdepartment and Excellence-Cluster “Universe,” Garching, Germany; Fischer, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Gaisser, M. O. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Giomataris, Y. [CEA/Saclay, DAPNIA, 91191 Gif-sur-Yvette Cedex, France; Grosse-Perdekamp, M. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA; Guidoboni, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Hacıömeroğlu, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Hoffstaetter, G. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Huang, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Incagli, M. [Physics Department, University and INFN Pisa, Pisa, Italy; Ivanov, A. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Kawall, D. [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA; Kim, Y. I. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; King, B. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Koop, I. A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia; Lazarus, D. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lebedev, V. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Lee, M. J. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, Y. H. [Korea Research Institute of Standards and Science, Daejeon 34141, South Korea; Lehrach, A. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Lenisa, P. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Levi Sandri, P. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Luccio, A. U. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lyapin, A. [Royal Holloway, University of London, Egham, Surrey, United Kingdom; MacKay, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Maier, R. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Makino, K. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Malitsky, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Marciano, W. J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meng, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meot, F. [Brookhaven National Laboratory, Upton, New York 11973, USA; Metodiev, E. M. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Harvard College, Harvard University, Cambridge, Massachusetts 02138, USA; Miceli, L. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Moricciani, D. [Dipartimento di Fisica dell’Univ. di Roma “Tor Vergata” and INFN Sezione di Roma Tor Vergata, Rome, Italy; Morse, W. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Nagaitsev, S. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Nayak, S. K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Orlov, Y. F. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Ozben, C. S. [Istanbul Technical University, Istanbul 34469, Turkey; Park, S. T. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pesce, A. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Petrakou, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pile, P. [Brookhaven National Laboratory, Upton, New York 11973, USA; Podobedov, B. [Brookhaven National Laboratory, Upton, New York 11973, USA; Polychronakos, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Pretz, J. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Ptitsyn, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Ramberg, E. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973, USA; Rathmann, F. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Rescia, S. [Brookhaven National Laboratory, Upton, New York 11973, USA; Roser, T. [Brookhaven National Laboratory, Upton, New York 11973, USA; Kamal Sayed, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Semertzidis, Y. K. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea; Senichev, Y. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Sidorin, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Silenko, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Research Institute for Nuclear Problems of Belarusian State University, Minsk, Belarus; Simos, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Stahl, A. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Stephenson, E. J. [Indiana University Center for Spacetime Symmetries, Bloomington, Indiana 47405, USA; Ströher, H. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Syphers, M. J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA; Talman, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Talman, R. M. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Tishchenko, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Touramanis, C. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Tsoupas, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Venanzoni, G. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Vetter, K. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA; Vlassis, S. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Won, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Physics Department, Korea University, Seoul 02841, South Korea; Zavattini, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Zelenski, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Zioutas, K. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of $10^{-29}e\\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000~TeV.

A storage ring experiment to detect a proton electric dipole moment.

Science.gov (United States)

Anastassopoulos, V; Andrianov, S; Baartman, R; Baessler, S; Bai, M; Benante, J; Berz, M; Blaskiewicz, M; Bowcock, T; Brown, K; Casey, B; Conte, M; Crnkovic, J D; D'Imperio, N; Fanourakis, G; Fedotov, A; Fierlinger, P; Fischer, W; Gaisser, M O; Giomataris, Y; Grosse-Perdekamp, M; Guidoboni, G; Hacıömeroğlu, S; Hoffstaetter, G; Huang, H; Incagli, M; Ivanov, A; Kawall, D; Kim, Y I; King, B; Koop, I A; Lazarus, D M; Lebedev, V; Lee, M J; Lee, S; Lee, Y H; Lehrach, A; Lenisa, P; Levi Sandri, P; Luccio, A U; Lyapin, A; MacKay, W; Maier, R; Makino, K; Malitsky, N; Marciano, W J; Meng, W; Meot, F; Metodiev, E M; Miceli, L; Moricciani, D; Morse, W M; Nagaitsev, S; Nayak, S K; Orlov, Y F; Ozben, C S; Park, S T; Pesce, A; Petrakou, E; Pile, P; Podobedov, B; Polychronakos, V; Pretz, J; Ptitsyn, V; Ramberg, E; Raparia, D; Rathmann, F; Rescia, S; Roser, T; Kamal Sayed, H; Semertzidis, Y K; Senichev, Y; Sidorin, A; Silenko, A; Simos, N; Stahl, A; Stephenson, E J; Ströher, H; Syphers, M J; Talman, J; Talman, R M; Tishchenko, V; Touramanis, C; Tsoupas, N; Venanzoni, G; Vetter, K; Vlassis, S; Won, E; Zavattini, G; Zelenski, A; Zioutas, K

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10 -29 e ⋅ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

Conceptual Design Report. Antiproton - Proton Collider Upgrade 20 GeV Rings. Technical Components and Civil Construction May, 1988

Energy Technology Data Exchange (ETDEWEB)

None

1988-05-01

This report contains a description of the design and cost estimate of two new 20 GeV rings which will be required to support the upgrade of the Fermilab Collider with a luminosity goal of 5x10 ³¹ cm^-2s^-1. The new rings include an antiproton post-accumulator, denoted the Antiproton Super Booster (ASB), and a proton post-booster, denoted the Proton Super Booster (PSB). The siting of the rings is shown in Figure I-1. Both rings are capable of operation at 20 GeV, eliminating the need for ever again injecting beam into the Main Ring below transition, and significantly enhancing Main Ring performance. The Antiproton Super Booster is designed to accept and accumulate up to 4x10¹² antiprotons from the existing Antiproton Accumulator, and deliver them to the Main Ring at 20 GeV for acceleration and injection into the Collider. It is also designed to accept diluted antiprotons from the Main Ring at 20 GeV for recooling. The PSB accepts 8.9 GeV protons from the existing Booster and accelerates them to 20 GeV for injection into the Main Ring. The PSB is designed to operate at 5 Hz. The siting shown in Figure I-1 has the attractive feature that it removes all Main Ring injection hardware from the AO straight section, opening the possibility of installing a third proton-antiproton interaction region in the Tevatron Collider.

Electron cloud instabilities in the Proton Storage Ring and Spallation Neutron Source

Directory of Open Access Journals (Sweden)

M. Blaskiewicz

2003-01-01

Full Text Available Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for the Oak Ridge Spallation Neutron Source are examined theoretically, numerically, and experimentally.

Ring-like spatial distribution of laser accelerated protons in the ultra-high-contrast TNSA-regime

Science.gov (United States)

Becker, G. A.; Tietze, S.; Keppler, S.; Reislöhner, J.; Bin, J. H.; Bock, L.; Brack, F.-E.; Hein, J.; Hellwing, M.; Hilz, P.; Hornung, M.; Kessler, A.; Kraft, S. D.; Kuschel, S.; Liebetrau, H.; Ma, W.; Polz, J.; Schlenvoigt, H.-P.; Schorcht, F.; Schwab, M. B.; Seidel, A.; Zeil, K.; Schramm, U.; Zepf, M.; Schreiber, J.; Rykovanov, S.; Kaluza, M. C.

2018-05-01

The spatial distribution of protons accelerated from submicron-thick plastic foil targets using multi-terawatt, frequency-doubled laser pulses with ultra-high temporal contrast has been investigated experimentally. A very stable, ring-like beam profile of the accelerated protons, oriented around the target’s normal direction has been observed. The ring’s opening angle has been found to decrease with increasing foil thicknesses. Two-dimensional particle-in-cell simulations reproduce our results indicating that the ring is formed during the expansion of the proton density distribution into the vacuum as described by the mechanism of target-normal sheath acceleration. Here—in addition to the longitudinal electric fields responsible for the forward acceleration of the protons—a lateral charge separation leads to transverse field components accelerating the protons in the lateral direction.

2-[(Pyridin-3-ylaminomethyl]phenol

Directory of Open Access Journals (Sweden)

Jing Xu

2011-12-01

Full Text Available In the title compound, C12H12N2O, the aromatic rings at either ends of the –CH2–NH– link are twisted by 68.79 (7°. In the crystal, the hydroxy substituent is a hydrogen-bond donor to the N atom of the pyridine ring of an adjacent molecule, and the hydrogen bond generates a chain along the b axis; it is also a hydrogen-bond acceptor to the amino group of another adjacent molecule. The two hydrogen bonds lead to the formation of a layer structure.

Proton accumulator ring injection studies

International Nuclear Information System (INIS)

Cooper, R.K.; Neil, V.K.

1977-01-01

Protons may be created in an accelerator or storage ring by stripping electrons from neutral hydrogen atoms that have been injected into the machine. Because Liouville's theorem is violated by this type of injection, particles may be continually injected into a region of phase space that is already populated, and the density in that region increases with time. A computational investigation was made of the evolution of the distribution of particles in longitudinal phase space during such an injection process for a storage ring operating below the transition energy. In one calculation, an rf cavity is present in the ring and particles are injected into the stable phase region once each revolution. The purpose of this calculation is to determine the rf voltage necessary to overcome the longitudinal self-forces and contain the particles within the region of stable phase. In a second calculation, the rf is turned off, so that there is spreading in azimuth of the injected particles (i.e., de-bunching). The de-bunching occurs because of the initial energy spread and the action of the self-forces. One purpose of the calculation is to determine the total energy spread after a given number of revolutions. Another purpose is to elucidate the effect of finite resistance in the vacuum tank walls. For sufficiently high current, the finite resistance can cause bunching of a beam that is initially uniform in azimuth. Therefore it might be expected that the finite resistance would inhibit or prevent de-bunching once the number of particles injected reaches some threshold, and that this threshold would depend upon the energy spread in the beam

(Pyridin-2-ylmethyl 6-bromo-2-oxo-1-[(pyridin-2-ylmethyl]-1,2-dihydroquinoline-4-carboxylate

Directory of Open Access Journals (Sweden)

Yassir Filali Baba

2018-02-01

Full Text Available In the central dihydroquinoline unit of the title compound, C22H16BrN3O3, the dihydropyridinone and benzene rings are inclined to one another by 2.0 (1°, while the outer pyridine rings are almost perpendicular to the plane of the dihydroquinoline ring system. The conformation of the molecule is partially determined by an intramolecular C—H...O hydrogen bond. In the crystal, molecules stack along the b-axis direction through a combination of C—H...N and C—H...O hydrogen bonds and π–π stacking interactions involving the dihydroquinoline units, with a centroid-to-centroid distance of 3.7648 (15 Å.

Crystal structures of N2,N3,N5,N6-tetrakis(pyridin-2-ylmethylpyrazine-2,3,5,6-tetracarboxamide and N2,N3,N5,N6-tetrakis(pyridin-4-ylmethylpyrazine-2,3,5,6-tetracarboxamide

Directory of Open Access Journals (Sweden)

Dilovan S. Cati

2017-02-01

Full Text Available The title compounds, C32H28N10O4· unknown solvent, (I, and C32H28N10O4, (II, are pyrazine-2,3,5,6-tetracarboxamide derivatives. In (I, the substituents are (pyridin-2-ylmethylcarboxamide, while in (II, the substituents are (pyridin-4-ylmethylcarboxamide. Both compounds crystallize in the monoclinic space group P21/n, with Z′ = 1 for (I, and Z′ = 0.5 for (II. The whole molecule of (II is generated by inversion symmetry, the pyrazine ring being situated about a center of inversion. In (I, the four pyridine rings are inclined to the pyrazine ring by 83.9 (2, 82.16 (18, 82.73 (19 and 17.65 (19°. This last dihedral angle involves a pyridine ring that is linked to the adjacent carboxamide O atom by an intramolecular C—H...O hydrogen bond. In compound (II, the unique pyridine rings are inclined to the pyrazine ring by 33.3 (3 and 81.71 (10°. There are two symmetrical intramolecular C—H...O hydrogen bonds present in (II. In the crystal of (I, molecules are linked by N—H...O and N—H...N hydrogen bonds, forming layers parallel to (10-1. The layers are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional framework. In the crystal of (II, molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [010] direction. The chains are linked by a weaker N—H...N hydrogen bond, forming layers parallel to the (101 plane, which are in turn linked by C—H...O hydrogen bonds, forming a three-dimensional structure. In the crystal of compound (I, a region of disordered electron density was treated with the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18]. Their contribution was not taken into account during refinement. In compound (II, one of the pyridine rings is positionally disordered, and the refined occupancy ratio for the disordered Car—Car—Npy atoms is 0.58 (3:0.42 (3.

Studies on beam extraction from the 1 GeV proton accumulator ring

International Nuclear Information System (INIS)

Goyal, Pradeep Kumar; Sharma, Amalendu; Kumar, Vinit; Ghodke, A.D.

2015-01-01

For the proposed Indian Spallation Neutron Source (ISNS), a 1 GeV proton Accumulator Ring (AR) is presently being designed at RRCAT. Two optics configurations of AR, namely FODO and Hybrid lattices are under consideration. Each lattice configuration has four superperiods. In this paper, preliminary studies on beam extraction from AR are presented for both the optics configurations. The extraction system will be accommodated in one of the long dispersion free straight sections. Bunch length of the proton beam in AR is 700 ns, and the revolution time of the bunch in AR is 1 ms. This leaves a gap of ∼300 ns for bunch extraction. The proton bunch will be extracted to Ring to Target Beam Transport (RTBT) line, with the help of fast kicker and septum magnets. In this paper, we present the details of the beam extraction scheme with suitable number of kicker magnets, and find out their optimal location and strength. Estimation of field error tolerances for kicker magnets is also presented. (author)

Magnetic measurements on the ring dipoles and quadrupoles for the Los Alamos proton storage ring

International Nuclear Information System (INIS)

Schermer, R.I.; Blind, B.; Jason, A.J.; Sawyer, G.A.

1985-01-01

This paper discusses magnetic measurements and shimming performed on the ring dipoles and quadrupoles for the Los Alamos Proton Storage Ring (PSR). For the dipoles, point-by-point field maps were obtained using a search coil that could be scanned over a three-dimensional grid. By appropriate machining of removable end blocks, all magnet lengths were adjusted to within 0.01% of a nominal value and all integrated multipoles were set within tolerance. Integrated fields of 20 PSR quadrupoles were measured using a rotating ''Morgan Coil'' and a digital spectrum analyzer. The magnets were shimmed to specifications by adjusting steel bolts threaded through the field clamps. 3 refs., 5 figs., 4 tabs

Development of an abort gap monitor for high-energy proton rings

International Nuclear Information System (INIS)

Beche, Jean-Francois; Byrd, John; De Santis, Stefano; Denes, Peter; Placidi, Massimo; Turner, William; Zolotorev, Max

2004-01-01

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

Development of an Abort Gap Monitor for High-Energy Proton Rings

International Nuclear Information System (INIS)

Beche, J.-F.; Byrd, J.; De Santis, S.; Denes, P.; Placidi, M.; Turner, W.; Zolotorev, M.

2004-01-01

The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the 'abort gap', and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

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.

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

Crystal structures of 2-benzylamino-4-(4-bromophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile and 2-benzylamino-4-(4-chlorophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile

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R. A. Nagalakshmi

2015-01-01

Full Text Available In the title compounds, C24H22BrN3, (I, and C24H22ClN3, (II, the 2-aminopyridine ring is fused with a cycloheptane ring, which adopts a half-chair conformation. The planes of the phenyl and benzene rings are inclined to that of the central pyridine ring [r.m.s. deviations = 0.0083 (1 and 0.0093 (1 Å for (I and (II, respectively] by 62.47 (17 and 72.51 (14°, respectively, in (I, and by 71.44 (9 and 54.90 (8°, respectively, in (II. The planes of the aromatic rings are inclined to one another by 53.82 (17° in (I and by 58.04 (9° in (II. In the crystals of both (I and (II, pairs of N—H...Nnitrile hydrogen bonds link the molecules, forming inversion dimers with R22(12 ring motifs. In (I, the resulting dimers are connected through C—H...Br hydrogen bonds, forming sheets parallel to (10-1, and π–π interactions [inter-centroid distance = 3.7821 (16 Å] involving inversion-related pyridine rings, forming a three-dimensional network. In (II, the resulting dimers are connected through π–π interactions [inter-centroid distance = 3.771 (2 Å] involving inversion-related pyridine rings, forming a two-dimensional network lying parallel to (001.

Study by electron paramagnetic resonance of the radiolysis of pyridine N-oxide in a vitreous methanol matrix

International Nuclear Information System (INIS)

Quaegebeur, J.P.; Perly, B.

1977-01-01

The analysis of esr spectra derived from γ irradiated pyridine N-oxide in a methanolic vitreous matrix at 77 K shows the presence of a mixture of 2- and 4-azacyclohexadienyl N-oxide radicals formed by the addition of the hydroxymethyl primary species to the pyridine ring. The structure of the different radicals was determined by comparison with spectra derived from several substituted pyridine N-oxides

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

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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°.

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

International Nuclear Information System (INIS)

Kovtyukh, A.

2007-01-01

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

2-[1-(1-Naphthyl-1H-1,2,3-triazol-4-yl]pyridine

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Ulrich S. Schubert

2009-05-01

Full Text Available In the crystal structure of the title compound, C17H12N4, the angle between the naphthalene and 1H-1,2,3-triazole ring systems is 71.02 (4° and that between the pyridine and triazole rings is 8.30 (9°.

Run permit software for the proton storage ring

International Nuclear Information System (INIS)

Bair, S.S.

1985-01-01

The Run Permit system is intended to protect equipment from radiation effects caused by having beam enabled when required equipment is not operational. This system will not allow beam unless certain devices are ready and will drop beam if any of these devices become inoperative. A system to provide such protection might be implemented in hardware. However, because the several operating modes of the Proton Storage Ring/Weapons Neutron Research facility require certain devices to be in different states (depending on mode), a dynamic configuration capability is needed, that is, a software solution is more feasible

Test of internal halo targets in the HERA proton ring

International Nuclear Information System (INIS)

Hast, C.; Hofmann, W.; Khan, S.; Knoepfle, K.T.; Reber, M.; Rieling, J.; Spahn, M.; Spengler, J.; Lohse, T.; Pugatch, V.

1994-07-01

Internal wire targets in the halo of stored proton beams provide a line source of proton-nucleus interactions for highest-rate fixed target experiments. We have studied such internal halo targets at the 820 GeV proton ring of the HERA ep collider. The tests showed that most of the protons in the beam halo - which would otherwise hit the collimators - can be brought to interaction in a relatively thin target wire at distances of 7 to 8 beam widths from the center of the beam. At less than 10% of the HERA total design current, and less than 20% of the current per bunch, interaction rates up to 8 MHz were observed, corresponding to more than 2 interactions per bunch crossing. The halo targets were used in parallel to the HERA luminosity operation; no significant disturbances of the HERA ep experiments, of the machine stability or beam quality were observed. We present data on the steady-state and transient behaviour of interaction rates and discuss the interpretation in terms of a simple beam dynamics model. Issues of short-, medium- and long-term rate fluctuations and of rate stabilization by feedback are addressed. (orig.)

Test of internal halo targets in the HERA proton ring

International Nuclear Information System (INIS)

Hast, C.; Hofmann, W.; Khan, S.; Knoepfle, K.T.; Reber, M.; Rieling, J.; Spahn, M.; Spengler, J.; Lohse, T.; Pugatch, V.

1995-01-01

Internal wire targets in the halo of stored proton beams provide a line source of proton-nucleus interactions for highest-rate fixed target experiments. We have studied such internal halo targets at the 820 GeV proton ring of the HERA ep collider. The tests showed that most of the protons in the beam halo - which would otherwise hit the collimators - can be brought to interaction in a relatively thin target wire at distances of 7 to 8 beam widths from the center of the beam. At less than 10% of the HERA total design current, and less than 20% of the current per bunch, interaction rates up to 8 MHz were observed, corresponding to more than 2 interactions per bunch crossing. The halo targets were used in parallel to the HERA luminosity operation; no significant disturbances of the HERA ep experiments, of the machine stability or beam quality were observed. We present data on the steady-state and transient behaviour of interaction rates and discuss the interpretation in terms of a simple beam dynamics model. Issues of short-, medium- and long-term rate fluctuations and of rate stabilization by feedback are addressed. ((orig.))

Synthesis of 1-Substituted-4-(Pyridin-4-yl)

African Journals Online (AJOL)

Purpose: To synthesize a new series of 1-substituted-4-(pyridin-4-yl) [1,2,4] triazolo [4,3-a]quinazolin- 5(4H)-ones and evaluate them for H1-antihistaminic activity with negligible side effects in guinea pigs. Methods: The synthesized compounds were characterized by Infrared spectroscopy (IR), proton nuclear magnetic ...

SAR studies directed toward the pyridine moiety of the sap-feeding insecticide sulfoxaflor (Isoclast™ active).

Science.gov (United States)

Loso, Michael R; Benko, Zoltan; Buysse, Ann; Johnson, Timothy C; Nugent, Benjamin M; Rogers, Richard B; Sparks, Thomas C; Wang, Nick X; Watson, Gerald B; Zhu, Yuanming

2016-02-01

Sap-feeding insect pests constitute a major insect pest complex that includes a range of aphids, whiteflies, planthoppers and other insect species. Sulfoxaflor (Isoclast™ active), a new sulfoximine class insecticide, targets sap-feeding insect pests including those resistant to many other classes of insecticides. A structure activity relationship (SAR) investigation of the sulfoximine insecticides revealed the importance of a 3-pyridyl ring and a methyl substituent on the methylene bridge linking the pyridine and the sulfoximine moiety to achieving strong Myzus persicae activity. A more in depth QSAR investigation of pyridine ring substituents revealed a strong correlation with the calculated logoctanol/water partition coefficient (SlogP). Model development resulted in a highly predictive model for a set of 18 sulfoximines including sulfoxaflor. The model is consistent with and helps explain the highly optimized pyridine substitution pattern for sulfoxaflor. Copyright © 2015 Elsevier Ltd. All rights reserved.

S.C. correction coils and magnets for the HERA proton ring

International Nuclear Information System (INIS)

Daum, C.; Geerinck, J.; Schmueser, P.

1986-05-01

The quadrupole and sextupole correction coils of the HERA proton ring are mounted on the cold beam pipe inside the main dipole magnets. Superferric dipole magnets for orbit correction are located adjacent to the main quadrupole magnets in a common cryostat which also contains the beam monitor. The design, manufacture and performance of both types of correction elements are described. (orig.)

2,3-Diamino­pyridinium 6-carb­oxy­pyridine-2-carboxyl­ate

Science.gov (United States)

Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

2011-01-01

The asymmetric unit of the title proton-transfer compound, C5H8N3 +·C7H4NO4 −, consists of one mono-deprotonated pyridine-2,6-dicarb­oxy­lic acid as anion and one protonated 2,3-diamino­pyridine as cation. The crystal packing shows extensive O—H⋯O, N—H⋯O and N—H⋯N hydrogen bonds. Thre are also several π–π inter­actions between the anions and also between the cations [centriod–centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å]. PMID:22199823

Pyridinium bis(pyridine-κNtetrakis(thiocyanato-κNferrate(III

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Sergii I. Shylin

2013-06-01

Full Text Available In the title compound, (C5H6N[Fe(NCS4(C5H5N2], the FeIII ion is coordinated by four thiocyanate N atoms and two pyridine N atoms in a trans arrangement, forming an FeN6 polyhedron with a slightly distorted octahedral geometry. Charge balance is achieved by one pyridinium cation bound to the complex anion via N—H...S hydrogen bonding. The asymmetric unit consists of one FeIII cation, four thiocyanate anions, two coordinated pyridine molecules and one pyridinium cation. The structure exhibits π–π interactions between pyridine rings [centroid–centroid distances = 3.7267 (2, 3.7811 (2 and 3.8924 (2 Å]. The N atom and a neighboring C atom of the pyridinium cation are statistically disordered with an occupancy ratio of 0.58 (2:0.42 (2.

Spin flipping a stored polarized proton beam at the IUCF cooler ring

International Nuclear Information System (INIS)

Phelps, R.A.

1995-01-01

We recently studied the spin flip of a vertically polarized 139 MeV proton beam stored in the IUCF Cooler Ring. We used an rf solenoid to induce a depolarizing resonance in the ring; we flipped the spin by varying the solenoid field's frequency through this resonance. We found a polarization loss after multiple spin flips less than 0.1% per flip; we also found that this loss increased for very slow frequency changes. This spin flip could reduce systematic errors in stored polarization beam experiments by allowing frequent beam polarization reversals during the experiment. copyright 1995 American Institute of Physics

Pyridine adsorption and diffusion on Pt(111) investigated with density functional theory

International Nuclear Information System (INIS)

Kolsbjerg, Esben L.; Groves, Michael N.; Hammer, Bjørk

2016-01-01

The adsorption, diffusion, and dissociation of pyridine, C 5 H 5 N, on Pt(111) are investigated with van der Waals-corrected density functional theory. An elaborate search for local minima in the adsorption potential energy landscape reveals that the intact pyridine adsorbs with the aromatic ring parallel to the surface. Piecewise interconnections of the local minima in the energy landscape reveal that the most favourable diffusion path for pyridine has a barrier of 0.53 eV. In the preferred path, the pyridine remains parallel to the surface while performing small single rotational steps with a carbon-carbon double bond hinged above a single Pt atom. The origin of the diffusion pathway is discussed in terms of the C 2 –Pt π-bond being stronger than the corresponding CN–Pt π-bond. The energy barrier and reaction enthalpy for dehydrogenation of adsorbed pyridine into an adsorbed, upright bound α-pyridyl species are calculated to 0.71 eV and 0.18 eV, respectively (both zero-point energy corrected). The calculations are used to rationalize previous experimental observations from the literature for pyridine on Pt(111).

Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

Science.gov (United States)

Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

2014-10-01

Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.

Status report on the Los Alamos proton storage ring

International Nuclear Information System (INIS)

Colton, E.; Neuffer, D.; Thiessen, H.A.

1988-01-01

The proton storage ring currently operates at an average current of 30 μA corresponding to 1.25 /times/ 10 13 protons per pulse (ppp) at a repetition rate of 15 Hz. The design operating current for the machine is 100 μA. We are limited to running at the reduced yield because of beam losses during the accumulation period. These losses are understood and arise mainly from emittance growths during the injection and multiple scattering in the stripping foil during the storage. During beam studies we have succeeded in accumulating in excess of 3.7 /times/ 10 13 ppp. We have also observed a coherent transverse instability at high charge levels. The signature for the instability is rapid coherent growth of the transverse beam size followed by a loss of beam in the machine. The threshold for the instability depends most strongly upon rf voltage and beam size. 3 refs., 1 fig., 1 tab

Crystal structure of the pyridine-diiodine (1/1) adduct.

Science.gov (United States)

Tuikka, Matti; Haukka, Matti

2015-07-01

In the title adduct, C5H5N·I2, the N-I distance [2.424 (8) Å] is remarkably shorter than the sum of the van der Waals radii. The line through the I atoms forms an angle of 78.39 (16)° with the normal to the pyridine ring.

Coherent instabilities of proton beams in accelerators and storage rings - experimental results, diagnosis and cures

International Nuclear Information System (INIS)

Schnell, W.

1977-01-01

The author discusses diagnosis and cure of proton beam instabilities in accelerators and storage rings. Coasting beams and bunched beams are treated separately and both transverse and longitudinal instabilities are considered. (B.D.)

Status of PSR [Proton Storage Ring

International Nuclear Information System (INIS)

Macek, R.J.

1989-01-01

The Los Alamos Proton Storage Ring (PSR) now operates with 35μA at 20-Hz pulse repetition rate. Beam availability during 1988 suffered because of a number of problems with hardware reliability and from narrow operating margins for beam spill in the extraction line. A strong effort is underway to improve reliability with an eventual goal of obtaining beam availability in excess of 75%. Beam losses and the resulting component activation have limited operating currents to their present values. In detailed studies of the problem, loss rates were found to be approximately proportional to the circulating current and can be understood by a detailed accounting of emittance growth in the two-step injection process along with Coulomb scattering of the stored beam during multiple traversals of the injection foil. It is now apparent that the key to reducing losses is in reducing the number of foil traversals. A program of upgrades to reduce losses and improve the operating current is being planned. 8 refs., 16 figs

Dihydropyridine-fused and pyridine-fused coumarins: Reduction on a glassy carbon electrode in dimethylformamide

International Nuclear Information System (INIS)

Nuñez-Vergara, Luis J.; Pardo-Jiménez, V.; Barrientos, C.; Olea-Azar, C.A.; Navarrete-Encina, P.A.; Squella, J.A.

2012-01-01

In this study, two series of dihydropyridine-fused and pyridine-fused coumarins were synthesised and electrochemically characterised in aprotic medium. In both series, the most easily reducible groups were the endocyclic carbonyl groups. The electrochemical mechanism for both types of compounds is strongly dependent on the experimental time-scale. Cyclic voltammetric (CV) reduction on a glassy carbon electrode (GCE) of the endocyclic carbonyl group of dihydropyridine-fused coumarins involves an ECEC mechanism with two electron transfer steps that are coupled with chemical reactions to produce the corresponding hemiacetal derivative. In the case of pyridine-fused coumarins, CV reduction of the endocyclic carbonyl group involves an EEC mechanism. ESR studies revealed the presence of a stabilised intermediate only for the pyridine-fused derivatives. Our theoretical study showed a spin density map of radical species delocalised mainly within the coumarin ring, indicating the reduction of the endocyclic carbonyl group. In the case of the dihydropyridine-fused derivatives, the mildly acid hydrogen of the dihydropyridine ring destabilises the radical via a father–son type reaction.

The PEP [positron-electron-proton] electron-positron ring: PEP Stage I

International Nuclear Information System (INIS)

Rees, J.R.

1974-01-01

The first stage of the positron-electron-proton (PEP) colliding-beam system which has been under joint study by a Lawrence Berkeley Laboratory-Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e/sup /plus//e/sup /minus// ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus around the interaction regions will be 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup /minus/2/s/sup/minus/1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross-section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described. 7 refs., 8 figs., 3 tabs

Reactivity of N-heterocyclic carbene-pyridine palladacyclopentadiene complexes toward halogen addition. The unpredictable course of the reaction.

Science.gov (United States)

Visentin, Fabiano; Santo, Claudio; Scattolin, Thomas; Demitri, Nicola; Canovese, Luciano

2017-08-08

As an extension of a previously published work we have reacted some palladacyclopentadiene complexes stabilized by bidentate N-heterocyclic carbene-pyridine or monodentate N-heterocyclic carbene-pyridine and isocyanide ligands with the halogens I 2 and Br 2 . All the bidentate and monodentate complexes react with halogens to give at first the expected σ-coordinated butadienyl fragment. However, two of the less hindered NHC carbene-pyridine bidentate butadienyl iodo derivatives undergo a further rearrangement and novel Pd(ii) complexes characterized by a ten term coordinative ring were isolated and characterized. In the most favorable case we were able to carry out the kinetics of rearrangement and measure its reaction rate. Moreover, we have surmised a plausible mechanism on the basis of a dedicated computational approach and in one case the surprising structure characterized by the ten term coordinative ring was resolved by X-ray diffraction.

Synthesis and Radiolabeling of Modified Peptides Attached to Heterocyclic Rings and Their Possible Medical Applications

International Nuclear Information System (INIS)

Shams El-Din, H.A.A.

2012-01-01

Keeping in mind the pharmacological potential of heterocyclic rings as well as the advantage of biodegradability and biocompatibility of amino acids/peptides, in this thesis we were prompted for the following: 1. Synthesis of novel dipeptide derivatives coupled with different heterocyclic rings (pyridine, 1,2,4-triazol-pyridine, 1,3,4-oxadiazolpyridine and tetrazol-pyridine rings). 2. Characterization of the synthesized compounds on the basis of their spectral data (IR, Mass and 1 H-NMR spectra). 3. Study their antimicrobial activity as one of their expected biological activities. 4. Study the radioiodination of some synthesized dipeptide derivatives. 5. Study the biodistribution of the radiolabeled compounds in normal mice as preliminary studies for the possibility of using them as agents for imaging and treatment.

8-Hydroxy-2-methylquinolinium tetrachlorido(pyridine-2-carboxylato-κ2N,Ostannate(IV

Directory of Open Access Journals (Sweden)

Ezzatollah Najafi

2011-02-01

Full Text Available In the reaction of pyridine-2-carboxylic acid and stannic chloride in the presence of 2-methyl-8-hydroxyquinoline, the 2-methyl-8-hydroxyquinoline is protonated, yielding the title salt, (C10H10NO[SnCl4(C6H4NO2]. The SnIV atom in the anion is N,O-chelated by a pyridine-2-carboxylate in a cis-SnNOCl4 octahedral geometry. The cation is linked to the anion by an O—H...O hydrogen bond.

Carbon filament beam profile monitor for high energy proton-antiproton storage rings

International Nuclear Information System (INIS)

Evans, L.R.; Shafer, R.E.

1979-01-01

The measurement of the evolution of the transverse profile of the stored beams in high energy proton storage rings such as the p-anti p colliders at CERN and at FNAL is of considerable importance. In the present note, a simple monitor is discussed which will allow almost non-destructive measurement of the profile of each individual proton and antiproton bunch separately. It is based on the flying wire technique first used at CEA and more recently at the CPS. A fine carbon filament is passed quickly through the beam, acting as a target for secondary particle production. The flux of secondary particles is measured by two scintillator telescopes, one for protons and one for antiprotons, having an angular acceptance between 30 and 100 mrad. Measurements of secondary particle production performed at FNAL in this angular range show that a very respectable flux can be expected

A proposal of a beam injection device for the proton storage ring of JAERI neutron science project

International Nuclear Information System (INIS)

Suzuki, Yasuo

1998-01-01

A new injection device (a charge-exchange device) with light and magnetic field, is proposed for a proton storage ring of JAERI Neutron Science Project. This injection device is composed of a neutralizer and an ionizer. The neutralizer strips electrons of H 0 beam into H - one with the undulator magnetic field. The ionizer which is composed of undulator magnets and an optical resonator placed along a straight part in the storage ring, can ionize effectively the H 0 beam excited to n=3 level by a laser beam into H + one. Adopting the 2nd harmonics of Nd : YAG laser, the powerful laser on the market can be used, and the required items of the technological development can be minimized. The energy of the particle beam, however, should be accelerated up to 1.587 GeV by 6% increase from 1.5 GeV. In this device, the non-charge-exchange rate and beam-spill can be minimized by decreasing the deflection angle of the beam which occurs at the charge-exchange process. This method can be realized with exiting technologies and there are not any effects on the trajectory of the ring-circulating proton beam due to scatterings by the foil as the usual charge-exchange devices. This device, therefore, will be an optimal and highly effective method of the least beam-spill as the injector of the high power proton storage ring. (author)

Acceleration of polarized protons and deuterons in the ion collider ring of JLEIC

Science.gov (United States)

Kondratenko, A. M.; Kondratenko, M. A.; Filatov, Yu N.; Derbenev, Ya S.; Lin, F.; Morozov, V. S.; Zhang, Y.

2017-07-01

The figure-8-shaped ion collider ring of Jefferson Lab Electron-Ion Collider (JLEIC) is transparent to the spin. It allows one to preserve proton and deuteron polarizations using weak stabilizing solenoids when accelerating the beam up to 100 GeV/c. When the stabilizing solenoids are introduced into the collider’s lattice, the particle spins precess about a spin field, which consists of the field induced by the stabilizing solenoids and the zero-integer spin resonance strength. During acceleration of the beam, the induced spin field is maintained constant while the resonance strength experiences significant changes in the regions of “interference peaks”. The beam polarization depends on the field ramp rate of the arc magnets. Its component along the spin field is preserved if acceleration is adiabatic. We present the results of our theoretical analysis and numerical modeling of the spin dynamics during acceleration of protons and deuterons in the JLEIC ion collider ring. We demonstrate high stability of the deuteron polarization in figure-8 accelerators. We analyze a change in the beam polarization when crossing the transition energy.

2,3-Diamino?pyridinium 6-carb?oxy?pyridine-2-carboxyl?ate

OpenAIRE

Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

2011-01-01

The asymmetric unit of the title proton-transfer compound, C5H8N3+·C7H4NO4−, consists of one mono-deprotonated pyridine-2,6-dicarboxylic acid as anion and one protonated 2,3-diaminopyridine as cation. The crystal packing shows extensive O—H...O, N—H...O and N—H...N hydrogen bonds. Thre are also several π–π interactions between the anions and also between the cations [centriod–centroid distances = 3.6634&...

4-Benzyl-6-bromo-2-(4-methoxyphenyl-4H-imidazo[4,5-b]pyridine monohydrate

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Y. Ouzidan

2010-04-01

Full Text Available The imidazopyridine fused ring in the title compound, C20H16BrN3O·H2O, is coplanar with the aromatic ring at the 2-position [dihedral angle = 5.2 (1°]. In the five-membered imidazo portion, the C—N bond whose C atom is also connected to the pyridine N atom has predominantly double-bond character [1.334 (2 Å] whereas the C—N bond whose atom is connected to the pyridine C atom has predominantly single-bond character [1.371 (2 Å]. The water molecule engages in hydrogen bonding with the latter N atom; it is also connected to a symmetry-related water molecule, generating a linear chain structure.

On the isomers of pyridine-4-carboxaldoxime and its nitrate salt, X-ray crystal structure and quantum chemical calculations

Science.gov (United States)

Soliman, Saied M.; Albering, Jörg; Abu-Youssef, Morsy A. M.

2017-07-01

The reaction between nitric acid and pyridine-4-carboxaldoxime (P4A) afford the corresponding pyridinum nitrate salt (P4AN). Its X-ray structure is measured and compared with the related P4A salts. The DFT/B3LYP results showed that both the P4A and P4AN favored the Syn-I form which has the lowest energy among the other possible isomers. Transition state calculations predicted that the Syn-I form is the thermodynamically and kinetically most stable form. The X-ray solid state structure of the new nitrate salt (P4AN) indicated that the labile proton favored the N-atom of the pyridine ring. DFT studies showed that the same is true for its solution in polar solvents. In contrast, the pyridinium cation is not favored either in the gas phase or solution of P4AN in nonpolar solvent. In these cases, the proton favored to bond with one O-atom from the nitrate group. Second order interaction energies and Mayer bond order values revealed these results. The bond order of the Nsbnd H bond is higher in polar solvents as well as at the experimental structure than either in the gas phase or non polar solvents. The topology parameters obtained from the atoms in molecules (AIM) analysis were used to describe the nature of the Nsbnd H and Osbnd H bonds. The bond critical points (BCP) were found to be close to the H-atoms in case of stronger interaction.

Multielement analysis of Picea rubens Sarg. Three-rings by proton-induced x-ray emission

International Nuclear Information System (INIS)

Hall, G.S.

1984-01-01

A 3.7 MeV external proton beam was employed to produce X-rays in Picea rubens Sarg. (red spruce). Intra-annual growth rings and several elements were quantitatively determined (P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Pb, Sr). The PIXE experimental set-up, rapid sample preparation methods, and some interesting observations are discussed. In addition, statistical analysis of the tree-ring element concentrations revealed that K, Cl, and Ca were slightly translocated whereas the other elements detected were not. 15 references, 1 figure, 1 table

Hydroxyl pyridine containing polybenzimidazole membranes for proton exchange membrane fuel cells

DEFF Research Database (Denmark)

Yang, Jingshuai; Xu, Yixin; Zhou, Lu

2013-01-01

A polybenzimidazole variant polymer containing hydroxyl pyridine groups, termed as OHPyPBI, was synthesized from 3,3'-diaminobenzidine tetrahydrochloride and 4-hydroxy-2,6-pyridinedicarboxylic acid. The thermal-oxidative stability of the OHPyPBI polymer was as high as that of poly[2,2'-(m-phenyle...

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

Directory of Open Access Journals (Sweden)

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.

Solid-State Examination of Conformationally Diverse Sulfonamide Receptors Based on Bis(2-anilinoethynyl)pyridine, -Bipyridine, and -Thiophene.

Science.gov (United States)

Berryman, Orion B; Johnson, Charles A; Vonnegut, Chris L; Fajardo, Kevin A; Zakharov, Lev N; Johnson, Darren W; Haley, Michael M

2015-03-04

Utilizing an induced-fit model and taking advantage of rotatable acetylenic C(sp)-C(sp 2 ) bonds, we disclose the synthesis and solid-state structures of a series of conformationally diverse bis-sulfonamide arylethynyl receptors using either pyridine, 2,2'-bipyridine, or thiophene as the core aryl group. Whereas the bipyridine and thiophene structures do not appear to bind guests in the solid state, the pyridine receptors form 2 + 2 dimers with water molecules, two halides, or one of each, depending on the protonation state of the pyridine nitrogen atom. Isolation of a related bis-sulfonimide derivative demonstrates the importance of the sulfonamide N-H hydrogen bonds in dimer formation. The pyridine receptors form monomeric structures with larger guests such as BF 4 - or HSO 4 - , where the sulfonamide arms rotate to the side opposite the pyridine N atom.

6-Bromo-1,3-di-2-propynyl-1H-imidazo[4,5-b]pyridin-2(3H-one

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S. Dahmani

2010-04-01

Full Text Available The room-temperature reaction of propargyl bromide and 6-bromo-1,3-dihydroimidazo[4,5-b]pyridin-2-one in dimethylformamide yields the title compound, C12H8BrN3O, which features nitrogen-bound propynyl substituents. The imidazopyridine fused ring is almost planar (r.m.s. deviation = 0.011 Å; the propynyl chains point in opposite directions relative to the fused ring. One acetylenic H atom is hydrogen bonded to the carbonyl O atom of an inversion-related molecule, forming a dimer; adjacent dimers are linked by a second acetylene–pyridine C—H...N interaction, forming a layer motif.

Emittance growth induced by electron cloud in proton storage rings

CERN Document Server

Benedetto, Elena; Coppa, G

2006-01-01

In proton and positron storage rings with many closely spaced bunches, a large number of electrons can accumulate in the beam pipe due to various mechanisms (photoemission, residual gas ionization, beam-induced multipacting). The so-formed electron cloud interacts with the positively charged bunches, giving rise to instabilities, emittance growth and losses. This phenomenon has been observed in several existing machines such as the CERN Super Proton Synchrotron (SPS), whose operation has been constrained by the electron-cloud problem, and it is a concern for the Large Hadron Collider (LHC), under construction at CERN. The interaction between the beam and the electron cloud has features which cannot be fully taken into account by the conventional and known theories from accelerators and plasma physics. Computer simulations are indispensable for a proper prediction and understanding of the instability dynamics. The main feature which renders the beam-cloud interactions so peculiar is that the the electron cloud...

2-(Pyridin-2-ylpyridinium trifluoromethanesulfonate

Directory of Open Access Journals (Sweden)

Ryosuke Abe

2017-05-01

Full Text Available Although in the title salt, C10H9N2+·CF3SO3−, the C—C and C—N bond lengths within the aromatic rings are normal, there is a considerable difference in the C—N—C angles at the protonated and unprotonated N atoms, viz. 123.42 (10 and 117.10 (11°, respectively. Bifurcated N—H...X (X = N or O hydrogen bonds form within the cation and between cation and anion. As a result, the cation exists in a cis conformation in the solid state. An obvious π–π contact is also present between the non-protonated pyridyl rings of neighbouring cations.

catena-Poly[[bromidocopper(I)]-?-?2,?1-3-(2-allyl-2H-tetra?zol-5-yl)pyridine

OpenAIRE

Wang, Wei

2008-01-01

The title compound, [CuBr(C9H9N5)] n , has been prepared by the solvothermal treatment of CuBr with 3-(2-allyl-2H-tetra?zol-5-yl)pyridine. It is a new homometallic CuI olefin coord?ination polymer in which the CuI atoms are linked by the 3-(2-allyl-2H-tetra?zol-5-yl)pyridine ligands and bonded to one terminal Br atom each. The organic ligand acts as a bidentate ligand connecting two neighboring Cu centers through the N atom of the pyridine ring and the double bond of the allyl group. A three-...

Conformational analysis of the deoxyribofuranose ring in DNA by means of sums of proton-proton coupling constants: A graphical method

International Nuclear Information System (INIS)

Rinkel, L.J.; Altona, C.

1987-01-01

A graphical method is presented for the conformational analysis of the sugar ring in DNA fragments by means of proton-proton couplings. The coupling data required for this analysis consist of sums of couplings, which are referred to as sigma 1' (= J1'2' + J1'2''), sigma 2' (= J1'2' + J2'3' + J2'2''), sigma 2'' (= J1'2'' + J2''3' + J2'2'') and sigma 3' (= J2'3' + J2''3' + J3'4'). These sums of couplings correspond to the distance between the outer peaks of the H1', H2', H2'' and H3' [31P] resonances, respectively, (except for sigma 2' and sigma 2'' in the case of a small chemical shift difference between the H2' and H2'' resonances) and can often be obtained from 1H-NMR spectra via first-order measurement, obviating the necessity of a computer-assisted simulation of the fine structure of these resonances. Two different types of graphs for the interpretation of the coupling data are discussed: the first type of graph serves to probe as to whether or not the sugar ring occurs as a single conformer, and if so to analyze the coupling data in terms of the geometry of this sugar ring. In cases where the sugar ring does not occur as a single conformer, but as a blend of N- and S-type sugar puckers, the second type of graph is used to analyze the coupling data in terms of the geometry and population of the most abundant form. It is shown that the latter type of analysis can be carried out on the basis of experimental values for merely sigma 1',sigma 2' and sigma 2'', without any assumptions or restrictions concerning a relation between the geometry of the N- and S-type conformer. In addition, the question is discussed as to how insight can be gained into the conformational purity of the sugar ring from the observed fine structure of the H1' resonance

Solid-State Examination of Conformationally Diverse Sulfonamide Receptors Based on Bis(2-anilinoethynyl)pyridine, -Bipyridine, and -Thiophene

Science.gov (United States)

Berryman, Orion B.; Johnson, Charles A.; Vonnegut, Chris L.; Fajardo, Kevin A.; Zakharov, Lev N.; Johnson, Darren W.; Haley, Michael M.

2015-01-01

Utilizing an induced-fit model and taking advantage of rotatable acetylenic C(sp)–C(sp2) bonds, we disclose the synthesis and solid-state structures of a series of conformationally diverse bis-sulfonamide arylethynyl receptors using either pyridine, 2,2′-bipyridine, or thiophene as the core aryl group. Whereas the bipyridine and thiophene structures do not appear to bind guests in the solid state, the pyridine receptors form 2 + 2 dimers with water molecules, two halides, or one of each, depending on the protonation state of the pyridine nitrogen atom. Isolation of a related bis-sulfonimide derivative demonstrates the importance of the sulfonamide N–H hydrogen bonds in dimer formation. The pyridine receptors form monomeric structures with larger guests such as BF4− or HSO4−, where the sulfonamide arms rotate to the side opposite the pyridine N atom. PMID:26405435

4-twist helix snake to maintain polarization in multi-GeV proton rings

Science.gov (United States)

Antoulinakis, F.; Chen, Y.; Dutton, A.; Rossi De La Fuente, E.; Haupert, S.; Ljungman, E. A.; Myers, P. D.; Thompson, J. K.; Tai, A.; Aidala, C. A.; Courant, E. D.; Krisch, A. D.; Leonova, M. A.; Lorenzon, W.; Raymond, R. S.; Sivers, D. W.; Wong, V. K.; Yang, T.; Derbenev, Y. S.; Morozov, V. S.; Kondratenko, A. M.

2017-09-01

Solenoid Siberian snakes have successfully maintained polarization in particle rings below 1 GeV, but never in multi-GeV rings, because the spin rotation by a solenoid is inversely proportional to the beam momentum. High energy rings, such as Brookhaven's 255 GeV Relativistic Heavy Ion Collider (RHIC), use only odd multiples of pairs of transverse B-field Siberian snakes directly opposite each other. When it became impractical to use a pair of Siberian Snakes in Fermilab's 120 GeV /c Main Injector, we searched for a new type of single Siberian snake that could overcome all depolarizing resonances in the 8.9 - 120 GeV /c range. We found that a snake made of one 4-twist helix and 2 dipoles could maintain the polarization. This snake design could solve the long-standing problem of significant polarization loss during acceleration of polarized protons from a few GeV to tens of GeV, such as in the AGS, before injecting them into multi-hundred GeV rings, such as RHIC.

4-twist helix snake to maintain polarization in multi-GeV proton rings

International Nuclear Information System (INIS)

Antoulinakis, F.; Chen, Y.; Dutton, A.; Rossi De La Fuente, E.; Haupert, S.

2017-01-01

Solenoid Siberian snakes have successfully maintained polarization in particle rings below 1 GeV, but never in multi-GeV rings, because the spin rotation by a solenoid is inversely proportional to the beam momentum. High energy rings, such as Brookhaven’s 255 GeV Relativistic Heavy Ion Collider (RHIC), use only odd multiples of pairs of transverse B-field Siberian snakes directly opposite each other. When it became impractical to use a pair of Siberian Snakes in Fermilab’s 120 GeV/c Main Injector, we searched for a new type of single Siberian snake that could overcome all depolarizing resonances in the 8.9–120 GeV/c range. We found that a snake made of one 4-twist helix and 2 dipoles could maintain the polarization. Here, this snake design could solve the long-standing problem of significant polarization loss during acceleration of polarized protons from a few GeV to tens of GeV, such as in the AGS, before injecting them into multi-hundred GeV rings, such as RHIC.

Interaction of ring current and radiation belt protons with ducted plasmaspheric hiss. 2. Time evolution of the distribution function

Science.gov (United States)

Kozyra, J. U.; Rasmussen, C. E.; Miller, R. H.; Villalon, E.

1995-11-01

The evolution of the bounce-averaged ring current/radiation belt proton distribution is simulated during resonant interactions with ducted plasmaspheric hiss. The plasmaspheric hiss is assumed to be generated by ring current electrons and to be damped by the energetic protons. Thus energy is transferred between energetic electrons and protons using the plasmaspheric hiss as a mediary. The problem is not solved self-consistently. During the simulation period, interactions with ring current electrons (not represented in the model) are assumed to maintain the wave amplitudes in the presence of damping by the energetic protons, allowing the wave spectrum to be held fixed. Diffusion coefficients in pitch angle, cross pitch angle/energy, and energy were previously calculated by Kozyra et al. (1994) and are adopted for the present study. The simulation treats the energy range, E>=80 keV, within which the wave diffusion operates on a shorter timescale than other proton loss processes (i.e., Coulomb drag and charge exchange). These other loss processes are not included in the simulation. An interesting result of the simulation is that energy diffusion maximizes at moderate pitch angles near the edge of the atmospheric loss cone. Over the simulation period, diffusion in energy creates an order of magnitude enhancement in the bounce-averaged proton distribution function at moderate pitch angles. The loss cone is nearly empty because scattering of particles at small pitch angles is weak. The bounce-averaged flux distribution, mapped to ionospheric heights, results in elevated locally mirroring proton fluxes. OGO 5 observed order of magnitude enhancements in locally mirroring energetic protons at altitudes between 350 and 1300 km and invariant latitudes between 50° and 60° (Lundblad and Soraas, 1978). The proton distributions were highly anisotropic in pitch angle with nearly empty loss cones. The similarity between the observed distributions and those resulting from this

Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylatocuprate(II trihydrate

Directory of Open Access Journals (Sweden)

Mohammad Ghadermazi

2008-05-01

Full Text Available In the title compound, (C4H14N2[Cu(C7H3NO42]·3H2O or (bdaH2[Cu(pydc2]·3H2O (where bda is butane-1,4-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid, the CuII atom is coordinated by four O atoms [Cu—O = 2.0557 (16–2.3194 (16 Å] and two N atoms [Cu—N = 1.9185 (18 and 1.9638 (18 Å] from two chelating rings of the pydc2− anions, which act as tridentate ligands. The geometry of the resulting CuN2O4 coordination can be described as distorted octahedral. The the two pydc2− fragments are almost perpendicular to one another [77.51 (11°]. To balance the charges, two centrosymmetric protonated butane-1,4-diammonium, (bdaH22+ cations are present. In the crystal structure, extensive O—H...O, N—H...O and C—H...O hydrogen bonds [D...A = 2.720 (2–3.446 (3 Å], ion pairing, C—O...π [O...π = 3.099 (2 Å] and π–π stacking interactions between the pydc2− rings [centroid–centroid distance = 3.5334 (15 Å] contribute to the formation of a three-dimensional supramolecular structure.

Spin crossover and high spin filtering behavior in Co-Pyridine and Co-Pyrimidine molecules

Science.gov (United States)

Wen, Zhongqian; Zhou, Liping; Cheng, Jue-Fei; Li, Shu-Jin; You, Wen-Long; Wang, Xuefeng

2018-03-01

We present a theoretical study on a series of cobalt complexes, which are constructed with cobalt atoms and pyridine/pyrimidine rings, using density functional theory. We investigate the structural and electric transport properties of spin crossover (SCO) Co complex with two spin states, namely low-spin configuration [LS] and high-spin configuration [HS]. Energy analyses of the two spin states imply that the SCO Co-Pyridine2 and Co-Pyrimidine2 complexes may display a spin transition process accompanied by a geometric modification driven by external stimuli. A nearly perfect spin filtering effect is observed in the Co-Pyrimidine2 complex with [HS] state. In addition, we also discover the contact-dependent transmission properties of Co-Pyridine2. These findings indicate that SCO Co complexes are promising materials for molecular spintronic devices.

A pinger system for the Los Alamos Proton Storage Ring

International Nuclear Information System (INIS)

Hardek, T.W.; Thiessen, H.A.

1991-01-01

Developers at the Proton Storage Ring have long desired a modulator and electrode combination capable of kicking the 800-MeV proton beam enough to conduct tune measurements with full intensity beams. At present this has been accomplished by reducing the voltage on one extraction kicker modulator and turning the other off. This method requires that all of the accumulated beam be lost on the walls of the vacuum chamber. In addition to tune measurements a more recent desire is to sweep out beam that may have leaked into the area between bunches. A four-meter electrode has been designed and constructed for the purpose. The design is flexible in that the electrode may be split in the center and rotated in order to provide vertical and horizontal electrodes each 2 meters long. In addition two solid-state pulse modulators that can provide 10kV in burst mode at up to 700 KHz have been purchased. This hardware and its intended use are described. 3 refs., 2 figs., 1 tab

Synthesis of polysubstituted 4,5,6,7-tetrahydrofuro[2,3-c]pyridines by a novel multicomponent reaction.

Science.gov (United States)

Fayol, Aude; Zhu, Jieping

2004-01-08

[reaction: see text] A novel three-component synthesis of tetrahydrofuro[2,3-c]pyridines from readily accessible starting materials is described. Simply heating a toluene solution of an aminopentynoate, an aldehyde, and an alpha-isocyanoacetamide in the presence of ammonium chloride provided the 4,5,6,7-tetrahydrofuro[2,3-c]pyridines in good to excellent yield. The fused ring system is produced in this one-pot process by the concomitant formation of five chemical bonds.

Storm-associated variations of equatorially mirroring ring current protons, 1--800 keV, at constant first adiabatic invariant

International Nuclear Information System (INIS)

Lyons, L.R.; Williams, D.J.

1976-01-01

Explorer 45 observations of ring current protons mirroring near the equator, 1--800 keV, are presented at constant first adiabatic invariant μ throughout the period of the December 17, 1971, geomagnetic storm. To obtain μ, simultaneous magnetic field and particle observations are used. Particle deceleration in response to the storm time magnetic field decrease causes ring current measurements viewed at constant energy to underestimate the storm time increase in proton intensities at energies approximately-less-than200 keV. This adiabatic deceleration also accounts for the large flux decreases observed at energies approximately-greater-than200 keV during the storm, in contradiction with previous results (Soraas and Davis, 1968) obtained using a model for the storm time magnetic field

4-twist helix snake to maintain polarization in multi-GeV proton rings

Directory of Open Access Journals (Sweden)

F. Antoulinakis

2017-09-01

Full Text Available Solenoid Siberian snakes have successfully maintained polarization in particle rings below 1 GeV, but never in multi-GeV rings, because the spin rotation by a solenoid is inversely proportional to the beam momentum. High energy rings, such as Brookhaven’s 255 GeV Relativistic Heavy Ion Collider (RHIC, use only odd multiples of pairs of transverse B-field Siberian snakes directly opposite each other. When it became impractical to use a pair of Siberian Snakes in Fermilab’s 120  GeV/c Main Injector, we searched for a new type of single Siberian snake that could overcome all depolarizing resonances in the 8.9–120  GeV/c range. We found that a snake made of one 4-twist helix and 2 dipoles could maintain the polarization. This snake design could solve the long-standing problem of significant polarization loss during acceleration of polarized protons from a few GeV to tens of GeV, such as in the AGS, before injecting them into multi-hundred GeV rings, such as RHIC.

N,N-Diethyl-4-[(E-(pyridin-3-yldiazenyl]aniline

Directory of Open Access Journals (Sweden)

Tatiana V. Timofeeva

2013-08-01

Full Text Available The molecule of the title compound, C15H18N4, adopts a trans conformation with respect to the diazo N=N bond. The dihedral angle between the benzene and pyridine rings in the molecule is 8.03 (5°. In the crystal, a weak C—H...π interaction arranges the molecules into a corrugated ribbon, with an antiparallel orientation of neighboring molecules propagating in the [100] direction.

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

Science.gov (United States)

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.

(E-4-Methoxy-3,5-dimethyl-2-[(3-nitrophenylethenyl]pyridine

Directory of Open Access Journals (Sweden)

Youness El Bakri

2016-12-01

Full Text Available In the crystal of the title compound, C16H16N2O3, weak C—H...O hydrogen bonds involving the nitro group as acceptor form chains extending in the b-axis direction. The chains are arranged into layers by π–π stacking interactions along the c-axis direction between the substituted pyridine rings, separated by 3.624 (1 Å.

The proton storage ring: Problems and solutions

International Nuclear Information System (INIS)

Macek, R.J.

1988-01-01

The Los Alamos Proton Storage Ring (PSR) now operates with 35μA at 20-Hz pulse repetition rate. Beam availability during 1988 suffered because of a number of problems with hardware reliability and from narrow operating margins for beam spill in the extraction line. A strong effort is underway to improve reliability with an eventual goal of obtaining beam availability in excess of 75%. Beam losses and the resulting component activation have limited operating currents to their present values. In detailed studies of the problem, loss rates were found to be approximately proportional to the circulating current and can be understood by a detailed accounting of emittance growth in the two-step injection process along with Coulomb scattering of the stored beam during multiple traversals of the injection foil. It is now apparent that the key to reducing losses is in reducing the number of foil traversals. A program of upgrades to reduce losses and improve the operating current is being planned. 8 refs., 17 figs., 2 tabs

The proton storage ring: Problems and solutions

International Nuclear Information System (INIS)

Macek, R.J.

1989-01-01

The Los Alamos Proton Storage Ring (PSR) now operates with 35μA at 20-Hz pulse repetition rate. Beam availability during 1988 suffered because of a number of problems with hardware reliability and from narrow operating margins for beam spill in the extraction line. A strong effort is underway to improve reliability with an eventual goal of obtaining beam availability in excess of 75%. Beam losses and the resulting component activation have limited operating currents to their present values. In detail studies of the problem, loss rates were found to be approximately proportional to the circulating current and can be understood by a detailed accounting of emittance growth in the two-step injection process along with Coulomb scattering of the stored beam during multiple traversals of the injection foil. It is now apparent that the key to reducing losses is in reducing the number of foil traversals. A program of upgrades to reduce losses and improve the operating current is being planned. 8 refs., 17 figs., 2 tabs

Synthesis and muscarinic receptor pharmacology of a series of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridine bioisosteres of arecoline

DEFF Research Database (Denmark)

Pedersen, H; Bräuner-Osborne, H; Ball, R G

1999-01-01

A series of O- and ring-alkylated derivatives of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridin-3-ol was synthesized via treatment of appropriately substituted 4-benzylamino-1,2,5,6-tetrahydropyridine-3-carboxamides with hydrogen sulfide and subsequent ring closure by oxidation with bromine. The mus...

The uses of electrostatic bending and focussing elements for auxiliary storage rings in large proton collider tunnels

International Nuclear Information System (INIS)

Winn, D.R.

1987-01-01

The authors discuss the possibility of using electrostatic elements, instead of magnets, for bending and focusing in auxiliary electron storage rings in the tunnels of large proton accelerators. For example, in the proposed SSC tunnel, electron beam energies of --100 GeV appear to be possible. Benefits of electrostatic systems over conventional magnets in cost, aperture, beam dynamics, radiation hardness, and power are presented. Electrostatic element designs are discussed, as are applications to electron, anti-proton and heavy ion beams

One-photon mass-analyzed threshold ionization (MATI) spectroscopy of pyridine: Determination of accurate ionization energy and cationic structure

Energy Technology Data Exchange (ETDEWEB)

Lee, Yu Ran; Kang, Do Won; Kim, Hong Lae, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr; Kwon, Chan Ho, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr [Department of Chemistry and Institute for Molecular Science and Fusion Technology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

2014-11-07

Ionization energies and cationic structures of pyridine were intensively investigated utilizing one-photon mass-analyzed threshold ionization (MATI) spectroscopy with vacuum ultraviolet radiation generated by four-wave difference frequency mixing in Kr. The present one-photon high-resolution MATI spectrum of pyridine demonstrated a much finer and richer vibrational structure than that of the previously reported two-photon MATI spectrum. From the MATI spectrum and photoionization efficiency curve, the accurate ionization energy of the ionic ground state of pyridine was confidently determined to be 73 570 ± 6 cm{sup −1} (9.1215 ± 0.0007 eV). The observed spectrum was almost completely assigned by utilizing Franck-Condon factors and vibrational frequencies calculated through adjustments of the geometrical parameters of cationic pyridine at the B3LYP/cc-pVTZ level. A unique feature unveiled through rigorous analysis was the prominent progression of the 10 vibrational mode, which corresponds to in-plane ring bending, and the combination of other totally symmetric fundamentals with the ring bending overtones, which contribute to the geometrical change upon ionization. Notably, the remaining peaks originate from the upper electronic state ({sup 2}A{sub 2}), as predicted by high-resolution photoelectron spectroscopy studies and symmetry-adapted cluster configuration interaction calculations. Based on the quantitatively good agreement between the experimental and calculated results, it was concluded that upon ionization the pyridine cation in the ground electronic state should have a planar structure of C{sub 2v} symmetry through the C-N axis.

ACCELERATION OF POLARIZED PROTONS AT RHIC

International Nuclear Information System (INIS)

HUANG, H.

2002-01-01

Relativistic Heavy Ion Collider (RHIC) ended its second year of operation in January 2002 with five weeks of polarized proton collisions. Polarized protons were successfully injected in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. This is the first time that polarized protons have been accelerated to 100 GeV. The machine performance and accomplishments during the polarized proton run will be reviewed. The plans for the next polarized proton run will be outlined

Influence of Proton Acceptors on the Proton-Coupled Electron Transfer Reaction Kinetics of a Ruthenium-Tyrosine Complex.

Science.gov (United States)

Lennox, J Christian; Dempsey, Jillian L

2017-11-22

A polypyridyl ruthenium complex with fluorinated bipyridine ligands and a covalently bound tyrosine moiety was synthesized, and its photo-induced proton-coupled electron transfer (PCET) reactivity in acetonitrile was investigated with transient absorption spectroscopy. Using flash-quench methodology with methyl viologen as an oxidative quencher, a Ru 3+ species is generated that is capable of initiating the intramolecular PCET oxidation of the tyrosine moiety. Using a series of substituted pyridine bases, the reaction kinetics were found to vary as a function of proton acceptor concentration and identity, with no significant H/D kinetic isotope effect. Through analysis of the kinetics traces and comparison to a control complex without the tyrosine moiety, PCET reactivity was found to proceed through an equilibrium electron transfer followed by proton transfer (ET-PT) pathway in which irreversible deprotonation of the tyrosine radical cation shifts the ET equilibrium, conferring a base dependence on the reaction. Comprehensive kinetics modeling allowed for deconvolution of complex kinetics and determination of rate constants for each elementary step. Across the five pyridine bases explored, spanning a range of 4.2 pK a units, a linear free-energy relationship was found for the proton transfer rate constant with a slope of 0.32. These findings highlight the influence that proton transfer driving force exerts on PCET reaction kinetics.

(E-3-[5-(Diphenylaminothiophen-2-yl]-1-(pyridin-3-ylprop-2-en-1-one

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Rui Li

2013-09-01

Full Text Available In the title compound, C24H18N2OS, the pyridine and the two phenyl rings are oriented at dihedral angles of 10.1 (5, 71.7 (6 and 68.7 (5°, respectively, to the central thiophene ring. In the crystal, pairs of weak C—H...O hydrogen bonds link inversion-related molecules, forming dimers. The dimers are linked by further weak C—H...O hydrogen bonds, forming chains running along the a-axis direction.

(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].

Electric fields, electron production, and electron motion at the stripper foil in the Los Alamos Proton Storage Ring

International Nuclear Information System (INIS)

Plum, M.

1995-01-01

The beam instability at the Los Alamos Proton Storage Ring (PSR) most likely involves coupled oscillations between electrons and protons. For this instability to occur, there must be a strong source of electrons. Investigation of the various sources of electrons in the PSR had begun. Copious electron production is expected in the injection section because this section contains the stripper foil. This foil is mounted near the center of the beam pipe, and both circulating and injected protons pass through it, thus allowing ample opportunity for electron production. This paper discusses various mechanisms for electron production, beam-induced electric fields, and electron motion in the vicinity of the foil

Crystal structure of [2-({4-[2,6-bis(pyridin-2-ylpyridin-4-yl]phenyl}(methylaminoethanol-κ3N,N′,N′′]bis(thiocyanato-κNzinc N,N-dimethylformamide monosolvate

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Shi-Chao Wang

2014-10-01

Full Text Available In the title compound, [Zn(NCS2(C24H22N4O]·C3H7NO, the ZnII cation is N,N′,N′′-chelated by one 2-({4-[2,6-bis(pyridin-2-ylpyridin-4-yl]phenyl}(methylaminoethanol ligand and coordinated by two thiocyanate anions in a distorted N5 trigonal–bipyramidal geometry. In the molecule, the three pyridine rings are approximately coplanar [maximum deviation = 0.026 (5 Å], and the mean plane of the three pyridine rings is twisted to the benzene ring with a small dihedral angle of 5.9 (2°. In the crystal, complex molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains propagated along [110]; π–π stacking is observed between adjacent chains [centroid–centroid distance = 3.678 (4 Å]. The dimethylformamide solvent molecules are linked with the complex chains via weak C—H...O hydrogen bonds.

Crystal structure of bis-[N-(2-hy-droxy-eth-yl)-N-methyl-dithio-carbamato-κ2S,S'](pyridine)-zinc(II) pyridine monosolvate and its N-ethyl analogue.

Science.gov (United States)

Poplaukhin, Pavel; Tiekink, Edward R T

2017-07-01

The common structural feature of the title compounds, [Zn(C 4 H 8 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (I) and [Zn(C 5 H 10 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (II), which differ by having di-thio-carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each Zn II atom by two non-symmetrically chelating di-thio-carbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine mol-ecule is connected to the Zn-containing mol-ecule via a (hy-droxy)O-H⋯N(pyridine) hydrogen bond. The resulting NS 4 coordination geometry is closer to a square-pyramid than a trigonal bipyramid in the case of (I), but almost inter-mediate between the two extremes in (II). The mol-ecular packing features (hy-droxy)O-H⋯O(hy-droxy) hydrogen bonds, leading to supra-molecular chains with a zigzag arrangement along [10-1] (I) or a helical arrangement along [010] (II). In (I), π-π [inter-centroid distances = 3.4738 (10) and 3.4848 (10) Å] between coordinating and non-coordinating pyridine mol-ecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π-π contacts occur between centrosymmetrically related pairs of coordinating pyridine mol-ecules [inter-centroid separation = 3.9815 (14) Å]. Further inter-actions, including C-H⋯π(chelate) inter-actions in (I), lead to a three-dimensional architecture in each case.

Electron - proton colliders

International Nuclear Information System (INIS)

Wiik, B.H.

1985-01-01

Electron-proton storage rings allow us to study the interaction between the two basic constituents of matter, electrons and quarks at very short distances. Such machines were first discussed in connection with the ISR but the idea was abandoned because of the anticipated low counting rate. The interest in electron-proton storage rings was rekindeled by the discovery of large pointlike cross sections in lepton-hardon interactions and several/sup 2-15/ projects have been discussed during the past decade. However, despite a glorious past, which includes the discovery of quarks and neutral currents, and a multitude of proposals no electron-proton storage ring has ever been built. What we might learn by studying electron-proton collisions at high energies is discussed. After some brief comments on present proposals the proposed DESY ep project HERA is described as an example of how to realize such a machine

Fast-extraction modulators for Los Alamos Scientific LaboratorY Proton Storage Ring

International Nuclear Information System (INIS)

Nunnally, W.C.; Hudgings, D.W.; Sarjeant, W.J.

1980-01-01

The development of a short-bunch mode fast-extraction modulator for the LASL proton storage ring has made necessary the design and development of a resonant transformer charging circuit and the design of a new FIB line circuit to provide bipolar pulse outputs with low prepulse, postpulse, and an optimum high-voltage switch environments. The systems are now being developed to operate reliably at the high-average powers required. The short-bunch mode fast-extraction modulator prototype is presently operating. The initial construction of the long-bunch mode fast-extraction modulator prototype is under way, with results expected within the year

Electrocatalytic oxidations of pyridine derivatives using Ru(IV) poly pyridine complex

International Nuclear Information System (INIS)

Oliveira, S.M. de.

1989-01-01

The oxidation reactions electro catalysed by bi pyridine oxo tri pyridine ruthenium perchlorate metallic complex from selected organic substrates are studied. The obtained results are compared with forecasting results showing the coherence of suggested mechanism. The substrates 2-, 2- and 4- picolines with its respective 1-oxides and 1,2 -; 1,3 - and 1,4 - dimethyl pyridine chloride salts were analysed. The oxidation of toluene as reference substrate was also studied and the mass spectra of oxidation products were interpreted. (M.C.K.)

Synthesis, Reactivity and Stability of Aryl Halide Protecting Groups towards Di-Substituted Pyridines

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Ptoton Mnangat Brian

2016-03-01

Full Text Available This paper reports the synthesis and reactivity of different Benzyl derivative protecting groups. The synthesis and stability of Benzyl halides, 4-methoxybenzyl halides, 3,5-dimethoxybenzyl halides, 3,4-dimethoxybenzyl halides, 3,4,5-trimethoxybenzyl halide protecting groups and their reactivity towards nitrogen atom of a di-substituted pyridine ring in formation of pyridinium salts is also reported.

Poly[diaquadi-μ-hydroxido-κ4O:O-dinitrato-κ4O:O′-bis[3-(pyridin-4-yl-κN-5-(pyridin-3-yl-1,2,4-oxadiazole]dicopper(II

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Longfei Wu

2012-04-01

Full Text Available The title compound, [Cu2(NO32(OH2(C12H8N4O2(H2O2]n, consists of a neutral polymeric CuII complex in which each CuII atom has a distorted octahedral geometry defined by a pyridyl N atom from a 3-(pyridin-3-yl-5-(pyridin-4-yl-1,2,4-oxadiazole ligand and five O atoms from a water molecule, two nitrates and two hydroxides. Two CuII ions are bridged by two hydroxide anions resulting in a Cu2O2 loop, located across an inversion center and connected by the nitrate anions into a broad two-dimensional polymeric structure parallel to (100. In the crystal, there are O—H...O hydrogen bonds between the coodinated water molecule and the nitrate and hydroxide, and between the hydroxide and the nitrate. Intermolecular π–π interactions are present between pyridine rings in adjacent two-dimensional structures, with a centroid–centroid distance of 3.582 (2 Å.

Microwave Determination of the Structure of Pyridine

Energy Technology Data Exchange (ETDEWEB)

Bak, B.; Hansen, L.; Rastrup-Andersen, J. [Chemical Laboratory of the University of Copenhagen, Copenhagen (Denmark)

1954-12-15

2‐, 3‐, and 4‐mono‐deutero‐pyridine have been prepared and the microwave spectra recorded. For each of the isotopic species 11—12 transitions (Q‐ and R‐branch lines) were localized, a number of which could be identified by their Stark effect. For all three species rotational constants of high precision were calculated. The material so provided in connection with known rotational constants for ordinary pyridine is insufficient for a complete determination of the ten geometrical parameters of the molecule. Seven models with a choice of C – H distances close to the correct value (1.075‐1.085 A) were considered one of which was shown to be consistent with electron‐diffraction work and current valence theory. In this model d(N – C(2)) = 1.340±0.005; d(C(2) – C(3)) = 1.390±0.005; d(C(3) – C(4)) = 1.400±0.005 A. The valence angles in the aromatic ring (starting with the C(6) – N – C(2) angle) are: 116° 42′; 124° 00′; 118° 36′; 118° 06′.

Formation of mono- and multilayers of metal complexes of 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine

NARCIS (Netherlands)

Werkman, P J; Wilms, H; Wieringa, R H; Schouten, A J

1998-01-01

The monolayer properties of the amphiphile, 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine have been studied by measuring the surface pressure-area isotherms. The amphiphile forms stable monolayers at the air-water interface and protonation of the monolayers occurs at pH values of 3.00 or lower.

Status of the experimental studies of the electron cloud at the Los Alamos proton storage ring

International Nuclear Information System (INIS)

Macek, R.J.; Browman, A.A.; Borden, M.J.; Fitzgerald, D.H.; McCrady, R.C.; Spickermann, T.J.; Zaugg, T.J.

2003-01-01

The electron cloud (EC) at the Los Alamos Proton Storage Ring (PSR) has been studied extensively for the past several years with an overall aim to identify and measure its important characteristics, the factors that influence these characteristics, and to relate these to the two-stream (e-p) transverse instability long observed at PSR. Some new results since PAC2001 are presented.

fac-Tris(pyridine-2-carboxylato-κ2N,Ocobalt(III

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Irina A. Golenia

2011-11-01

Full Text Available In the title compound, [Co(C6H4NO23], the CoIII ion lies on a threefold rotation axis and is in a distorted octahedral environment defined by three N and three O donor atoms from three fac-disposed pyridine-2-carboxylate ligands. The ligands are coordinated in a chelate fashion, forming three five-membered rings. In the crystal, translationally related complex molecules are organized into columns along [001] via C—H...O hydrogen bonds.

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.

NRL ion ring program

International Nuclear Information System (INIS)

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

1977-01-01

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

Crystal structure of bis(azido-κNbis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]cobalt(II

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Abdelhakim Laachir

2015-05-01

Full Text Available In the mononuclear title complex, [Co(N32(C12H8N4S2], the cobalt(II atom is located on an inversion centre and displays an axially weakly compressed octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by N atoms of the azide anions. The thiadiazole and pyridine rings linked to the metal are almost coplanar, with a maximum deviation from the mean plane of 0.0273 (16 Å. The cohesion of the crystal is ensured by weak C—H...N hydrogen bonds and by π–π interactions between pyridine rings [intercentroid distance = 3.6356 (11 Å], forming a layered arrangement parallel to (001. The structure of the title compound is isotypic with that of the analogous nickel(II complex [Laachir et al. (2013. Acta Cryst. E69, m351–m352].

Crystal structure of bis(azido-κNbis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]nickel(II

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Abdelhakim Laachir

2015-02-01

Full Text Available Reaction of 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole and sodium azide with nickel(II triflate yielded the mononuclear title complex, [Ni(N32(C12H8N4S2]. The NiII ion is located on a centre of symmetry and is octahedrally coordinated by four N atoms of the two bidentate heterocyclic ligands in the equatorial plane. The axial positions are occupied by the N atoms of two almost linear azide ions [N—N—N = 178.8 (2°]. The thiadiazole and pyridine rings of the heterocyclic ligand are almost coplanar, with a maximum deviation from the mean plane of 0.0802 (9 Å. The cohesion of the crystal structure is ensured by π–π interactions between parallel pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.6413 (14 Å], leading to a layered arrangement of the molecules parallel to (001.

Design summary of the magnet support structures for the proton storage ring injection line upgrade

International Nuclear Information System (INIS)

Bernardin, J.D.; Ledford, J.E.; Smith, B.G.

1997-05-01

This report summarizes the technical engineering and design issues associated with the Proton Storage Ring (PSR) Injection Line upgrade of the Los Alamos Neutron Science Center (LANSCE). The main focus is on the engineering design calculations of several magnet support structures. The general procedure based upon a set number of design criteria is outlined, followed by a case-by-case summary of the engineering design analyses, reutilization or fabrication callouts and design safety factors

Crystal structure of bis-(μ-3-nitro-benzoato)-κ3O,O':O;κ3O:O,O'-bis-[bis-(3-cyano-pyridine-κN1)(3-nitro-benzoato-κ2O,O')cadmium].

Science.gov (United States)

Hökelek, Tuncer; Akduran, Nurcan; Özen, Azer; Uğurlu, Güventürk; Necefoğlu, Hacali

2017-03-01

The asymmetric unit of the title compound, [Cd 2 (C 7 H 4 NO 4 ) 4 (C 6 H 4 N 2 ) 4 ], contains one Cd II atom, two 3-nitro-benzoate (NB) anions and two 3-cyano-pyridine (CPy) ligands. The two CPy ligands act as monodentate N(pyridine)-bonding ligands, while the two NB anions act as bidentate ligands through the carboxyl-ate O atoms. The centrosymmetric dinuclear complex is generated by application of inversion symmetry, whereby the Cd II atoms are bridged by the carboxyl-ate O atoms of two symmetry-related NB anions, thus completing the distorted N 2 O 5 penta-gonal-bipyramidal coordination sphere of each Cd II atom. The benzene and pyridine rings are oriented at dihedral angles of 10.02 (7) and 5.76 (9)°, respectively. In the crystal, C-H⋯N hydrogen bonds link the mol-ecules, enclosing R 2 2 (26) ring motifs, in which they are further linked via C-H⋯O hydrogen bonds, resulting in a three-dimensional network. In addition, π-π stacking inter-actions between parallel benzene rings and between parallel pyridine rings of adjacent mol-ecules [shortest centroid-to-centroid distances = 3.885 (1) and 3.712 (1) Å, respectively], as well as a weak C-H⋯π inter-action, may further stabilize the crystal structure.

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

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Hoong-Kun Fun

2012-03-01

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

Golden Jubilee photos: ISR - The first proton-proton interactions

CERN Document Server

2004-01-01

At the inauguration ceremony for the Intersecting Storage Rings (ISR) on 16 October 1971, the man in charge of their construction, Kjell Johnsen, presented the "key" to the machine to Edoardo Amaldi, President of Council. Seated on the stage with them for this symbolic event were Victor Weisskopf, Marcel Antonioz, Willy Jentschke (seen on the left of the photo) and Werner Heisenberg (on the far right). On 27 January that year, in a world premier, signals produced by proton-proton collisions had been observed at the ISR. The protons, supplied by the PS, were injected into two identical rings, each measuring 300 metres in diameter, and collided head on at the 8 points where the rings intersected. The installation, which remained in operation until 1984, gave physicists access to a wide range of energies for hadron physics, hitherto restricted to the data from cosmic ray studies. The many technological challenges that were met at the ISR, in the fields of vacuum technology and stochastic cooling for instance,...

Theory and design aspects of the 1 GeV proton compressor ring for pulsed beams of spallation neutrons and muons

International Nuclear Information System (INIS)

Rees, G.H.

1988-05-01

In the present paper, an outline design is presented for a 50 Hz, 1 GeV proton compressor ring of Japanese Hadron Project. The design aims are to provide two pulses of 1 GeV protons with an average current of 200 μA, one pulse with the time duration of 20 ns and the other of 100 - 200 ns. Very important aspects of magnet lattice, injection scheme, bunch compression process, beam instabilities are discussed. (author)

FIRST POLARIZED PROTON COLLISIONS AT RHIC

International Nuclear Information System (INIS)

ROSER, T.; AHRENS, L.; ALESSI, J.; BAI, M.; BEEBE-WANG, J.; BRENNAN, J.M.; BROWN, K.A.; BUNCE, G.; CAMERON, P.; COURANT, E.D.; DREES, A.; FISCHER, W.; FLILLER, R. III; GLENN, W.; HUANG, H.; LUCCIO, A.U.; MACKAY, W.W.; MAKDISI, Y.; MONTAG, C.; PILAT, F.; PTITSYN, V.; SATOGATA, T.

2002-01-01

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180 o about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV

Tinkering at the main-ring lattice

Energy Technology Data Exchange (ETDEWEB)

Ohnuma, S.

1982-08-23

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

Mitigation of the electron-cloud effect in the PSR and SNS proton storage rings by tailoring the bunch profile

International Nuclear Information System (INIS)

Pivi, M.; Furman, M.A.

2003-01-01

For the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electroncloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure

Di-μ-iodido-bis(iodido{methyl 4-[(pyridin-2-ylmethylideneamino]benzoate-κ2N,N′}cadmium

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Tushar S. Basu Baul

2013-11-01

Full Text Available The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O22], is generated by the application of a centre of inversion. The Cd—I bond lengths of the central core are close and uniformly longer than the exocyclic Cd—I bond. The coordination sphere of the CdII atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-ylmethylideneamino]benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C—H...O and C—H...π interactions, each involving the pyridine ring.

A novel method for the biosynthesis of deuterated proteins with selective protonation at the aromatic rings of Phe, Tyr and Trp

International Nuclear Information System (INIS)

Rajesh, Sundaresan; Nietlispach, Daniel; Nakayama, Hiroshi; Takio, Koji; Laue, Ernest D.; Shibata, Takehiko; Ito, Yutaka

2003-01-01

A novel biosynthetic strategy is described for the preparation of deuterated proteins containing protons at the ring carbons of Phe, Tyr and Trp, using the aromatic amino acid precursor shikimic acid. Specific protonation at aromatic side chains, with complete deuteration at C α/β positions was achieved in proteins overexpressed in bacteria grown in shikimate-supplemented D 2 O medium. Co-expression of a shikimate transporter in prototrophic bacteria resulted in protonation levels of 62-79%, whereas complete labeling was accomplished using shikimate auxotrophic bacteria. Our labeling protocol permits the measurement of important aromatic side chain derived distance restraints in perdeuterated proteins that could be utilized to enhance the accuracy of NMR structures calculated using low densities of NOEs from methyl selectively protonated samples

Resonant beam behavior studies in the Proton Storage Ring

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S. Cousineau

2003-07-01

Full Text Available We present studies of space-charge-induced beam profile broadening at high intensities in the Proton Storage Ring (PSR at Los Alamos National Laboratory. We investigate the profile broadening through detailed particle-in-cell simulations of several experiments and obtain results in good agreement with the measurements. We interpret these results within the framework of coherent resonance theory. With increasing intensity, our simulations show strong evidence for the presence of a quadrupole-mode resonance of the beam envelope with the lattice in the vertical plane. Specifically, we observe incoherent tunes crossing integer values, and large amplitude, nearly periodic envelope oscillations. At the highest operating intensities, we observe a continuing relaxation of the beam through space charge forces leading to emittance growth. The increase of emittance commences when the beam parameters encounter an envelope stop band. Once the stop band is reached, the emittance growth balances the intensity increase to maintain the beam near the stop band edge. Additionally, we investigate the potential benefit of a stop band correction to the high intensity PSR beam.

Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

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Ana Gabriela Conceição-Vertamatti

2015-03-01

Full Text Available Background: Ruthenium (Ru tetraamines are being increasingly used as nitric oxide (NO carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH34(Py(NO]3+, trans-[RuII(Cl(NO (cyclan](PF62, and trans-[RuII(NH34(4-acPy(NO]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M. After voltage stabilization, a single concentration (10−6 M of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

Linking heterometallic rings for quantum information processing and amusement.

Science.gov (United States)

Timco, Grigore A; Faust, Thomas B; Tuna, Floriana; Winpenny, Richard E P

2011-06-01

Linking polymetallic cages can be a method for creating new structures and new properties. In this tutorial review we use heterometallic anti-ferromagnetically coupled rings (AF-rings) as exemplars for three approaches that can be used to link cage compounds. The first of three routes involves an ion-pair interaction supported by hydrogen-bonding interactions, which allows the synthesis of hybrid rotaxanes among other materials. The second route involves functionalising the exterior of the AF-ring so that it will act as a Lewis base; complexes involving coordination of pyridine to bridging monometallic and dimetallic fragments are discussed. The third route involves creating a vacancy on one site of the AF-ring, and then using the ring as a Lewis acid. Di-imine ligands can then be used to link the AF-rings into dimers. A brief discussion of the physical properties of these systems is also included.

Temperature dependence of (+)-catechin pyran ring proton coupling constants as measured by NMR and modeled using GMMX search methodology

Science.gov (United States)

Fred L. Tobiason; Stephen S. Kelley; M. Mark Midland; Richard W. Hemingway

1997-01-01

The pyran ring proton coupling constants for (+)-catechin have been experimentally determined in deuterated methanol over a temperature range of 213 K to 313 K. The experimental coupling constants were simulated to 0.04 Hz on the average at a 90 percent confidence limit using a LAOCOON method. The temperature dependence of the coupling constants was reproduced from the...

Octa-akis(4-amino-pyridine)-1κN,2κN-aqua-2κO-μ-carbonato-1:2κO,O':O''-dinickel(II) dichloride penta-hydrate.

Science.gov (United States)

Fun, Hoong-Kun; Sinthiya, A; Jebas, Samuel Robinson; Ravindran Durai Nayagam, B; Alfred Cecil Raj, S

2008-10-18

In the title compound, [Ni(2)(CO(3))(C(5)H(6)N(2))(8)(H(2)O)]Cl(2)·5H(2)O, one of the the Ni(II) ions is six-coordinated in a distorted octa-hedral geometry, with the equatorial plane defined by four pyridine N atoms from four amino-pyridine ligands, the axial positions being occupied by one water O and a carbonate O atom. The other Ni(II) ion is also six-coordinated, by four other pyridine N atoms from four other amino-pyridine ligands and two carbonate O atoms to complete a distorted octa-hedral geometry. In the crystal structure, mol-ecules are linked into an infinite three-dimensional network by O-H⋯O, N-H⋯Cl, N-H⋯O, O-H⋯N, C-H⋯O, C-H⋯N and C/N-H⋯π inter-actions involving the pyridine rings.

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.

{1-[1-(2-Hydroxyphenylethylidene]-2-(pyridin-2-yl-κNhydrazine-κ2N′,O}{1-[1-(2-oxidophenylethylidene]-2-(pyridin-2-yl-κNhydrazine-κ2N′,O}nickelate(II nitrate hemihydrate

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Sarr Mamour

2018-05-01

Full Text Available The 2-hydrazinopyridine precursor has been widely used to prepare ligands of various kinds by condensation with carbonyl compounds. These types of ligands are suitable for synthesizing novel transition metal (II complexes with interesting magnetic properties. In this context we have synthesized the ligand 1-(2-hydroxyphenyl-2-ethylidene-2-(pyridin-2-ylhydrazine (HL which was used in the preparation of the mononuclear title complex, [Ni(C13H12N3O(C13H13N3O]NO3·0.5H2O. As a result of the presence of HL and L in the [{Ni(HL(L}]+ unit, the complex appears to be a supramolecular dimer composed of the Δ(− and Λ(− optical isomers, which are linked by strong hydrogen-bonds. As well as the dimer generated by two mononuclear [{Ni(HL(L}]+ cations, the asymmetric unit also contains two nitrate anions and one water molecule. Each Ni atom is coordinated to two ligand molecules by a nitrogen atom of the pyridine ring, an imine nitrogen atom and a phenolic oxygen atom of one of the ligand molecules and a phenolate oxygen atom of the other organic molecules. The environment around the cation is a distorted octahedron. The basal planes are defined by the two nitrogen atoms of the pyridine rings and the two phenolic oxygen atoms of the ligand, the apical positions being occupied by the azomethine atoms. The O atoms of one of the nitrate ions are disordered over two sets of sites in a 0.745 (9:0.255 (9 ratio. In the crystal, the dimers are linked by numerous hydrogen bonds, forming a three-dimensional framework.

Isotypic crystal structures of 1-benzyl-4-(4-bromophenyl-2-imino-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile and 1-benzyl-4-(4-fluorophenyl-2-imino-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile

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R. A. Nagalakshmi

2014-11-01

Full Text Available The molecules of the two isotypic title compounds, C25H24BrN3, (I, and C25H24FN3, (II, comprise a 2-iminopyridine ring fused with a cyclooctane ring. In (I, the cyclooctane ring adopts a twisted chair–chair conformation, while in (II, this ring adopts a twisted boat–chair conformation. The dihedral angles between the planes of the pyridine ring and the bromobenzene and phenyl rings are 80.14 (12 and 71.72 (13°, respectively, in (I. The equivalent angles in (II are 75.25 (8 and 68.34 (9°, respectively. In both crystals, inversion dimers linked by pairs of C—H...N interactions generate R22(14 loops, which are further connected by weak C—H...π interactions, generating (110 sheets.

Fluorescent property of 3-hydroxymethyl imidazo[1,2-a]pyridine and pyrimidine derivatives

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Velázquez-Olvera Stephania

2012-08-01

Full Text Available Abstract Background Imidazo[1,2-a]pyridines and pyrimidines are important organic fluorophores which have been investigated as biomarkers and photochemical sensors. The effect on the luminescent property by substituents in the heterocycle and phenyl rings, have been studied as well. In this investigation, series of 3-hydroxymethyl imidazo[1,2-a]pyridines and pyrimidines were synthesized and evaluated in relation to fluorescence emission, based upon the hypothesis that the hydroxymethyl group may act as an enhancer of fluorescence intensity. Results Compounds of both series emitted light in organic solvents dilutions as well as in acidic and alkaline media. Quantitative fluorescence spectroscopy determined that both fused heterocycles fluoresced more intensely than the parent unsubstituted imidazo[1,2-a]azine fluorophore. In particular, 3-hydroxymethyl imidazo[1,2-a]pyridines fluoresced more intensely than 3-hydroxymethyl imidazo[1,2-a]pyrimidines, the latter emitting blue light at longer wavelengths, whereas the former emitted purple light. Conclusion It was concluded that in most cases the hydroxymethyl moiety did act as an enhancer of the fluorescence intensity, however, a comparison made with the fluorescence emitted by 2-aryl imidazo[1,2-a]azines revealed that in some cases the hydroxymethyl substituent decreased the fluorescence intensity.

Rapid anaerobic mineralization of pyridine in a subsurface sediment inoculated with a pyridine-degrading Alcaligenes sp

Energy Technology Data Exchange (ETDEWEB)

Ronen, Z; Bollag, J M [Pennsylvania State Univ., University Park, PA (United States). Lab. of Soil Biochemistry

1992-05-01

A denitrifying bacterium capable of pyridine mineralization under anaerobic conditions was isolated from polluted soil. The bacterium, identified as Alcaligenes sp., was used in inoculation experiments. A subsurface sediment from a polluted site was amended with 10 {mu}g/g {sup 14}C-labeled pyridine, and 250 {mu}g/g nitrate, and then inoculated with the bacterium at an inoculum size of 4.5x10{sup 7} cells/g. After 44 h incubation at 28deg C under anaerobic conditions, 67% of the radioactivity was recovered as {sup 14}CO{sub 2}: 2% was extracted with 50% methanol, and 24% was recovered by combustion of the sediment. Analysis of the methanol extract revealed that no pyridine could be detected in the inoculated sediment. In contrast, mineralization of pyridine by the native microflora in the sediment occurred much more slowly: After 7 days of incubation only 10% of the added radioactivity was recovered as {sup 14}CO{sub 2}. At an inoculum size of 2x10{sup 3} cells/g pyridine mineralization was not as effective as at an inoculum size of 2x10{sup 7} cells/g. It is presumed that suppression of the introduced bacteria by the native microflora of the sediment prevents degradation at a low inoculum size. Amending the sediment with nitrate and phosphate improved pyridine mineralization by the introduced bacterium. These findings demonstrate the feasibility of using soil inoculation anaerobically for the bioremediation of pyridine-polluted soils. (orig.).

Poly[dibromidobis[μ-1-(pyridin-4-ylmethyl-1H-1,2,4-triazole-κ2N:N′]cadmium

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Xiu-Zhi Xu

2011-02-01

Full Text Available The title coordination polymer, [CdBr2(C8H8N42]n, arose from a layer-separated diffusion synthesis at room temperature. The title compound is isotypic with the I and Cl analogues. The Cd atom, located on an inversion center, is coordinated by two bromide ions and four N atoms (two from triazole rings and two from pyridyl rings in a distorted trans-CdBr2N4 octahedral arrangement. The bridging 1-(4-pyridylmethyl-1H-1,2,4-triazole ligands are twisted [dihedral angle between the triazole and pyridine rings = 72.56 (13°], affording a two-dimensional 44 sheet structure in the crystal.

Synthesis of a Bis(thiophenolate)pyridine Ligand and Its Titanium, Zirconium, and Tantalum Complexes

KAUST Repository

Lenton, Taylor N.

2012-11-12

A precursor to a new tridentate LX 2 type ligand, bis(thiophenol)pyridine ((SNS)H 2 = (2-C 6H 4SH) 2-2,6-C 5H 3N), was prepared. Bis(thiophenolate)pyridine complexes of Ti, Zr, and Ta having dialkylamido coligands were synthesized and structurally characterized. The zirconium complex (SNS)Zr(NMe 2) 2 (4) displays C 2 symmetry in the solid state, unlike a related bis(phenolate)pyridine compound, C s-symmetric (ONO)Ti(NMe 2) 2. This change is likely the result of strain about the sulfur atom in the six-membered chelate with longer metal-sulfur and carbon-sulfur bonds. Solid-state structures of tantalum complexes (SNS)Ta(NMe 2) 3 (5) and (SNS)TaCl(NEt 2) 2 (6) also display pronounced C 2 twisting of the SNS ligand. 1D and 2D NMR experiments show that 5 is fluxional, with rotation about the Ta-N(amide) bonds occurring on the NMR time scale that interchange the equatorial amide methyl groups (ΔG ‡ 393 = 25.0(3) kcal/mol). The fluxional behavior of 6 in solution was also studied by variable-temperature 1H NMR. Observation of separate signals for the diastereotopic protons of the methylene unit of the diethylamide indicates that the complex remains locked on the NMR time scale in one diastereomeric conformation at temperatures below -50 °C, fast rotation about the equatorial amide Ta-N bonds occurs at higher temperature (ΔG ‡ 393 = 13.4(3) kcal/mol), and exchange of diastereomeric methylene protons occurs via inversion at Ta that interconverts antipodes (ΔG ‡ 393 ≈ 14(1) kcal/mol). © 2012 American Chemical Society.

Beam position monitor multiplexer controller upgrade at the LAMPF proton storage ring

International Nuclear Information System (INIS)

Scarborough, W.K.; Cohen, S.

1992-01-01

The beam position monitor (BPM) is one of the primary diagnostic tools used for the tuning of the proton storage ring (PSR) at the Clinton P. Anderson Meson Physics Facility (LAMPF). A replacement for the existing, monolithic, wire-wrapped microprocessor-based BPM multiplexer controller has been built. The controller has been redesigned as a modular system retaining the same functionality of the original system built in 1981. Individual printed circuit cards are used for each controller function to insure greater maintainability and ease of keeping a spare parts inventory. Programmable logic device technology has substantially reduced the component count of the new controller. Diagnostic software was written to support the development of the upgraded controller. The new software actually uncovered some flaws in the original CAMAC interface. (author)

27 CFR 21.122 - Pyridine bases.

Science.gov (United States)

2010-04-01

....122 Pyridine bases. (a) Alkalinity. One ml of pyridine bases dissolved in 10 ml of water is titrated... condenser having a water jacket not less than 400 mm in length. A standardized thermometer is placed in the.... Dissolve 1 ml of pyridine bases in 100 ml of water. (1) Ten ml of this solution are treated with 5 ml of 5...

Design of a power amplifier for the LAMPF proton storage ring transverse damper system

International Nuclear Information System (INIS)

Lunsford, J.S.

1981-01-01

A power amplifier has been designed to drive the 50-Ω stripline deflection structures in the transverse active damper of the Los Alamos 800-MeV Proton Storage Ring (PSR). The unit will provide 600-V peak-to-peak with a dc-to-100-MHz bandwidth. Other important characteristics include < 40-ns delay time, 50-dB voltage gain, and 4-ns risetime with < 5% overshoot and ringing. Because of the current-drive properties of the amplifier, two amplifiers could be combined to provide over 1000-V peak-to-peak into 50 Ω, with very little bandwidth degradation. Components in the power amplifier that represent new designs are a 20-tube distributed-amplifier output stage; a driver stage, using VMOS FET and bipolar transistors; a high-voltage probe, with good dc stability and 150-MHz bandwidth; a transient suppressor circuit, using PIN diodes to protect the transistorized drivers from tube arcing; a nonlinear amplifier to compensate for the nonlinear characteristics of the distributed amplifier; and a first-fail indicator circuit to aid in locating the prime causes of equipment failures

Development of a high current H- injector for the proton storage ring at LAMPF

International Nuclear Information System (INIS)

York, R.L.; Stevens, R.R.; DeHaven, R.A.; McConnell, J.R.; Chamberlin, E.P.; Kandarian, R.

1984-01-01

A new high-current H - injector has been installed at LAMPF for the Proton Storage Ring. The injector is equipped with a multicusp surface-production H - ion source that was developed at LAMPF. The ion source is capable of long-term operation at 20 mA of H - current at 10% duty factor and with normalized beam emittance of 0.08 cm-mrad (95% beam fraction). Details of the development program, the injector design, and initial operating experience are discussed. Included in the discussion is a comparison of intensity and emittance measurements of the same H - beam at 100 keV and 750 keV. 4 references, 6 figures

The "g-2" Muon Storage Ring

CERN Multimedia

CERN PhotoLab

1974-01-01

The "g-2" muon storage ring, shortly before completion in June 1974. Bursts of pions (from a target, hit by a proton beam from the 26 GeV PS) are injected and polarized muons from their decay are captured on a stable orbit. When the muons decay too, their precession in the magnetic field of the storage ring causes a modulation of the decay-electron counting rate, from which the muon's anomalous magnetic moment can be determined. In 1977, the "g-2" magnets were modified to build ICE (Initial Cooling Experiment), a proton and antiproton storage ring for testing stochastic and electron cooling. Later on, the magnets had a 3rd life, when the ion storage ring CELSIUS was built from them in Uppsala. For later use as ICE, see 7711282, 7802099, 7809081,7908242.

Acid-base strengths in pyridine

NARCIS (Netherlands)

Bos, M.; Dahmen, E.A.M.F.

1971-01-01

Although pyridine is a solvent with a low dielectric constant, spectrophotometric determinations show simple dissociation without ion pairs as intermediates for some sulfonphthaleins and polynitrophenols in pyridine. The salts of a number of amines and hydrochloric acid, perchloric acid and picric

Inter- and intra-annular proton exchange in gaseous benzylbenzenium ions (protonated diphenylmethane)

OpenAIRE

Kuck, Dietmar; Bäther, Wolfgang

1986-01-01

Two distinct proton exchange reactions occur in metastable gaseous benzylbenzenium ions, generated by isobutane chemical ionization of diphenylmethane and four deuterium-labelled analogues. Whereas the proton ring-walk at the benzenium moiety is fast giving rise to a completely random intraannular proton exchange, the interannular proton exchange is surprisingly slow and competes with the elimination of benzene. A kinetic isotope effect of kH/kD= 5 has been determined for the interannular pro...

Pyridine-2,6-diyl dinitroxides as room-temperature triplet ligands

Energy Technology Data Exchange (ETDEWEB)

Kawakami, Hinako; Tonegawa, Asato; Ishida, Takayuki, E-mail: takayuki.ishida@uec.ac.jp [Department of Engineering Science, The University of Electro-Communications, Tokyo (Japan)

2016-02-01

We have proposed tert-butyl 2-pyridyl nitroxide radicals as a promising paramagnetic chelating ligand, where the direct radical-metal bond leads to strong magnetic interaction. We successfully synthesized and isolated PyBN derivatives (pyridine-2,6-diyl bis(tert-butyl nitroxides)). The molecular and crystal structures of the target biradicals, MesPyBN, AntPyBN and tBuOPyBN were determined from the X-ray crystal structure analysis, which possess mesityl, 9-anthryl and tert-butoxy groups at the 5-position of the pyridine ring, respectively. The ground triplet state was characterized by means of SQUID susceptometry for each compound. On heating, the χ{sub m}T values of all the PyBN derivatives increased and reached a plateau at ca. 1.0 cm{sup 3} K mol{sup −1} at 300 K. It implies that biradicals behaved as triplet molecules even at room temperature, or 2J/k{sub B} >> 300 K. From the decay monitored in solution electron-spin resonance spectroscopy, MesPyBN was the most persistent, while tBuOPyBN was the most reactive, of the three.

Clinical application of proton magnetic resonance spectroscopy in differential diagnosis of intracranial lesions with ring-like enhancement

International Nuclear Information System (INIS)

Lai Ying; Cheng Kailiang; Zhang Mengchao; Liu Yunxia; Wang Wei

2009-01-01

Objective: To study the value of clinical application of 1 H proton magnetic resonance spectroscopy ( 1 H MRS) in the differential diagnosis of intracranial lesions with ring-like enhancement. Methods: 28 cases were diagnosed of intracranial lesions with ring-like enhancement by clinical examination and pathologic test. A total of 28 ratios cases included 6 cases high grade glioma, 10 cases of metastatic carcinoma (n=10) and 12 cases of brain abscess, after examined with 1HMRS, the ratios of various metabolites in focal center, enhancement ring,perifocal edema region and normal control group were detected and compared. Results: The ratios of NAA/Cho, Cho/Cr and NAA/Cr in focal center had no significantly differences between high grade glioma and metastatic carcinoma (P>0.05). The peak of NAA was significantly different between high grade glioma and metastatic carcinoma (P 0.05). The peak of AA was characteristic of brain abscess. The ratio of Cho/Cr 0 in brain abscess was significantly lower than those in high grade glioma and metastatic carcinoma (P 0 denoted the Cho content of contralateral normal brain region). These results accorded with the result of pathological examination. Conclusion: 1 HMRS can improve the diagnostic accuracy of intracranial lesions with ring-like enhancement. (authors)

An energy recovery electron linac-on-ring collider

International Nuclear Information System (INIS)

Merminga, L.; Krafft, G.A.; Lebedev, V.A.; Ben-Zvi, I.

2000-01-01

We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10 33 (per nucleon) level have been proposed recently as a means for studying hadronic structure. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations (2) reduction of the synchrotron radiation load in the detectors (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed and a list of required R and D for the realization of such a design is presented

Accumulator ring design for the NSNS project

International Nuclear Information System (INIS)

Weng, W.T.; Alessi, J.; Beebe-Wang, J.

1997-01-01

The goal of the proposed National Spallation Neutron Source (NSNS) is to provide a short pulse proton beam of about 0.5 μs with average beam power of 1 MW. To achieve such purpose, a proton storage ring operated at 60 Hz with 1 x 10 14 protons per pulse at 1 GeV is required. The Accumulator Ring (AR) receives 1 msec long H - beam bunches of 28 mA from a 1 GeV linac. Scope and design performance goals of the AR are presented, other possible technological choices and design options considered, but not adopted, are also briefly reviewed

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.

Beam pinging, sweeping, shaking, and electron/ion collecting, at the Proton Storage Ring

International Nuclear Information System (INIS)

Hardek, T.W.; Macek, R.J.; Plum, M.A.; Wang, T.S.F.

1993-01-01

We have built, installed and tested a pinger for use as a general diagnostic at the Los Alamos Proton Storage Ring (PSR). Two 4-m-long parallel-plate electrodes with a plate spacing of 10.2 cm provide kicks of up to 1.1 mrad. A pair of solid-state pulsers may be operated in a single-pulse mode for beam pinging (tune measurements) or in a burst mode at up to 700 kHz pulse rates for beam sweeping. During our 1992 operating period we used the pinger for beam sweeping, for beam shaking, for measuring the tune shift, and we have used it as an ion chamber. Using the pinger as an ion chamber during production conditions has yielded some surprising results

COMMISSIONING CNI PROTON POLARIMETERS IN RHIC

International Nuclear Information System (INIS)

HUANG, H.; BRAVAR, A.; LI, Z.; MACKAY, W.W.; MAKDISI, Y.; RESCIA, S.; ROSER, T.; SURROW, B.; BUNCE, G.; DESHPANDE, A.; GOTO, Y.; ET AL

2002-01-01

Two polarimeters based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region have been installed and commissioned in the Blue and Yellow rings of RHIC during the first RHIC polarized proton collider run. Each polarimeter consists of ultra-thin carbon targets and six silicon detectors. With newly developed wave form digitizers, they provide fast and reliable polarization information for both rings

fac-Tris(pyridine-2-carboxyl­ato-κ2 N,O)cobalt(III)

Science.gov (United States)

Golenia, Irina A.; Boyko, Alexander N.; Kotova, Natalia V.; Haukka, Matti; Kalibabchuk, Valentina A.

2011-01-01

In the title compound, [Co(C6H4NO2)3], the CoIII ion lies on a threefold rotation axis and is in a distorted octa­hedral environment defined by three N and three O donor atoms from three fac-disposed pyridine-2-carboxyl­ate ligands. The ligands are coordinated in a chelate fashion, forming three five-membered rings. In the crystal, translationally related complex molecules are organized into columns along [001] via C—H⋯O hydrogen bonds. PMID:22219826

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

Proton NMR for Measuring Quantum Level Crossing in the Magnetic Molecular Ring Fe10

International Nuclear Information System (INIS)

Julien, M.; Jang, Z.H.; Borsa, F.; Julien, M.; Lascialfari, A.; Borsa, F.; Horvatic, M.; Caneschi, A.; Gatteschi, D.

1999-01-01

The proton nuclear spin-lattice relaxation rate 1/T 1 has been measured as a function of temperature and magnetic field (up to 15thinspthinspT) in the molecular magnetic ring Fe 10 ( OCH 3 ) 20 (O 2 CCH 2 Cl) 10 (Fe10). Striking enhancement of 1/T 1 is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing. copyright 1999 The American Physical Society

SNS accumulator ring design and space charge considerations

International Nuclear Information System (INIS)

Weng, W.T.

1998-01-01

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5micros with average beam power of 1MW. To achieve such purpose, a proton storage ring operated at 60Hz with 1 x 10 14 protons per pulse at 1GeV is required. The Accumulator Ring (AR) receives 1msec long H - beam bunches of 28mA from a 1GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generation and beam collimation etc. is discussed

The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

International Nuclear Information System (INIS)

Podulka, W.J.; Greenly, J.B.; Anderson, D.E.; Glidden, S.C.; Hammer, D.A.; Omelchenko, Yu.A.; Sudan, R.N.

1996-01-01

The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10 17 protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs

The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

Energy Technology Data Exchange (ETDEWEB)

Podulka, W J; Greenly, J B; Anderson, D E; Glidden, S C; Hammer, D A; Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

1997-12-31

The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10{sup 17} protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs.

(E-5,6-Dimethoxy-2-(pyridin-4-ylmethylidene-2,3-dihydro-1H-inden-1-one

Directory of Open Access Journals (Sweden)

Mohamed Ashraf Ali

2010-11-01

Full Text Available The molecule of the title compound, C17H15NO3, is slightly twisted, with a dihedral angle of 12.12 (3° between the dihydroindenone group and the pyridine ring. In the crystal, molecules are connected into layers parallel to the ab plane via intermolecular C—H...O hydrogen bonds. Weak π–π [centroid–centroid distance = 3.5680 (6 Å] interactions are also observed.

Crystal structure of 2-amino-1,3-dibromo-6-oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium bromide monohydrate

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Md. Serajul Haque Faizi

2015-11-01

Full Text Available In the title hydrated salt, C12H8Br2N3O+·Br−·H2O, which was synthesized by the reaction of the pyridine derivative Schiff base N1,N4-bis(pyridine-2-ylmethylenebenzene-1,4-diamine with bromine, the asymmetric unit contains a 2-amino-1,3-dibromo-6-oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium cation, with a protonated pyridine moiety, a bromide anion and a water molecule of solvation. The cation is non-planar with the dibromo-substituted benzene ring, forming dihedral angles of 24.3 (4 and 11.5 (4° with the fused pyridine and pyrazine ring moieties, respectively. In the crystal, the cations are linked through a centrosymmetric hydrogen-bonded cyclic R42(8 Br2(H2O2 unit by N—H...Br, N—H...O and O—H...Br hydrogen bonds, forming one-dimensional ribbons extending along b, with the planes of the cations lying parallel to (100.

5-Bromo-N3-[(E-(6-bromopyridin-2-ylmethylidene]pyridine-3,4-diamine

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Mingjian Cai

2011-12-01

Full Text Available The title compound, C11H8Br2N4, is a Schiff base obtained from 6-bromopicolinaldehyde and 5-bromopyridine-3,4-diamine. The molecule has an E configuration about the C=N bond and the dihedral angle between the two pyridine rings is 14.02 (1°. The observed conformation is stabilised by an intramolecular N—H...N hydrogen bond. In the crystal, molecules are stacked along the b axis and are linked through N—H...N hydrogen bonds into chains along the c axis.

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.

Proton injection and RF capture in the national spallation neutron source

International Nuclear Information System (INIS)

Luccio, A.U.; Beebe-Wang, J.; Maletic, D.

1997-01-01

The accelerator system for the 1 to 5 MW National Spallation Neutron Source (NSNS) consists of a linac followed by a 1 GeV proton accumulator ring. Since the ring is a very high current machine, the injection and rf capture of the protons is deeply affected by transverse and longitudinal space charge effects. Results of numerical simulation of the process are presented together with considerations on methods and results of space charge treatment in high intensity proton storage rings

Efficient Hydrogen Storage and Production Using a Catalyst with an Imidazoline-Based, Proton-Responsive Ligand.

Science.gov (United States)

Wang, Lin; Onishi, Naoya; Murata, Kazuhisa; Hirose, Takuji; Muckerman, James T; Fujita, Etsuko; Himeda, Yuichiro

2017-03-22

A series of new imidazoline-based iridium complexes has been developed for hydrogenation of CO 2 and dehydrogenation of formic acid. One of the proton-responsive complexes bearing two -OH groups at ortho and para positions on a coordinating pyridine ring (3 b) can catalyze efficiently the chemical fixation of CO 2 and release H 2 under mild conditions in aqueous media without using organic additives/solvents. Notably, hydrogenation of CO 2 can be efficiently carried out under CO 2 and H 2 at atmospheric pressure in basic water by 3 b, achieving a turnover frequency of 106 h -1 and a turnover number of 7280 at 25 °C, which are higher than ever reported. Moreover, highly efficient CO-free hydrogen production from formic acid in aqueous solution employing the same catalyst under mild conditions has been achieved, thus providing a promising potential H 2 -storage system in water. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Giving Protons a Boost

CERN Multimedia

2004-01-01

The first of LHC's superconducting radio-frequency cavity modules has passed its final test at full power in the test area of building SM18. These modules carry an oscillating electric field that will accelerate protons around the LHC ring and help maintain the stability of the proton beams.

(E-6-Amino-1,3-dimethyl-5-[(pyridin-2-ylmethylideneamino]pyrimidine-2,4(1H,3H-dione

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Irvin Booysen

2011-09-01

Full Text Available In the title compound, C12H13N5O2, a Schiff-base-derived chelate ligand, the non-aromatic heterocycle and its substituents essentially occupy one common plane (r.m.s. of fitted non-H atoms = 0.0503 Å. The N=C bond is E-configured. Intracyclic angles in the pyridine moiety cover the range 117.6 (2–124.1 (2°. Intra- and intermolecular N—H...N and N—H...O hydrogen bonds are observed in the crystal structure, as are intra- and intermolecular C—H...O contacts which, in total, connect the molecules into a three-dimensional network. The shortest ring-centroid-to-ring-centroid distance of 3.5831 (14 Å is between the two different types of six-membered rings.

N-(3-{[(Z-(3-Hydroxy-4-methylphenylimino]methyl}pyridin-2-ylpivalamide

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Şehriman Atalay

2016-03-01

Full Text Available The molecular structure of the title compound, C18H21N3O2, contains pivalamide, pyridin and hydroxy-methylphenyl moieties. The whole molecule is not planar, the dihedral angle between the benzene rings being 34.84 (7°. The molecular conformation is stabilized by an intramolecular N—H...N hydrogen bond. In the crystal, molecules are linked by O—H...O, O—H...N and C—H...O hydrogen bonds. The C and H atoms of the tert-butyl group disordered over two sets of sites with an occupancy ratio of 0.692 (5:0.308 (5.

SNS accumulator ring design and space charge considerations

Energy Technology Data Exchange (ETDEWEB)

Weng, W.T.

1998-08-01

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5 {micro}s with average beam power of 1 MW. To achieve such purpose, a proton storage ring operated at 60 Hz with 1 {times} 10{sup 14} protons per pulse at 1 GeV is required. The Accumulator Ring (AR) receives 1 msec long H{sup {minus}} beam bunches of 28 mA from a 1 GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1 mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generatino and beam collimation etc. is discussed.

SNS ACCUMULATOR RING DESIGN AND SPACE CHARGE CONSIDERATIONS

Energy Technology Data Exchange (ETDEWEB)

WENG,W.T.

1998-05-04

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5{micro}s with average beam power of 1MW. To achieve such purpose, a proton storage ring operated at 60Hz with 1 x 10{sup 14} protons per pulse at 1GeV is required. The Accumulator Ring (AR) receives 1msec long H{sup {minus}} beam bunches of 28mA from a 1GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generation and beam collimation etc. is discussed.

The synthesis, characterization and optical properties of novel 1,3,4-oxadiazole-containing imidazo[1,5-a]pyridine derivatives

International Nuclear Information System (INIS)

Ge Yanqing; Hao Benqian; Duan Guiyun; Wang Jianwu

2011-01-01

A series of novel substituted 1,3,4-oxadiazole derivatives were synthesized by the reaction of 3-butyl-1-chloroimidazo[1,5-a]pyridine-7-carbohydrazide with propionyl chloride and substituted benzoic chloride in the presence of phosphorus oxychloride. The compounds were characterized using IR, 1 H NMR, 13 C NMR and HRMS. Absorption and fluorescence spectra were measured in dichloromethane; an intense absorption maxima was noted at ca. 290 nm and emission maxima was noted at ca. 470 nm. The absorption spectra of the 1,3,4-oxadiazole derivatives reveal that a phenyl and an ethyl group attached to the 1,3,4-oxadiazole ring markedly influenced the maximum absorption. The structures based on density function theory (DFT) calculation show planar configurations for the compounds. The calculated molecular orbital correlates well with their absorption. - Research highlights: → Novel imidazo[1,5-a]pyridine derivatives were synthesized. → The structures were determined by IR, 1 H NMR, 13 C NMR and HRMS spectra. → We investigated the absorption and fluorescence spectral characteristics of the compounds. → The side group in 1,3,4-oxadiazole ring can affect its photophysical properties markedly. → Quantum calculation correlates well with their absorption.

Protonation sites of aromatic compounds in (+) atmospheric pressure photoionization

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung Hwan; Ahmed, Arif [Dept. of Chemistry, Kyungpoo k National University, Daegu (Korea, Republic of)

2017-02-15

Reaction enthalpy of hydrogen transfer reactions of aromatic compounds has been observed to be greatly affected by the exact location of the protonation site. Therefore, to clearly identify the protonation location, each candidate protonation site for 43 aromatic compounds were theoretically determined and their location was compared with that determined based on experimental MS data. Only the basic nitrogen atom is favorable as a protonation site for pyridine-type aromatic compounds, whereas carbon atoms are preferable for the protonation of pyrrole-type compounds. The most favorable protonation sites for aniline or methylated aniline-type aromatic compounds are either the nitrogen atom in the amine group or the carbon atom at the para-position to the amine group. Like pyrrole-type compounds, aromatic compounds with amine groups also favor protonation at the carbon atom instead of at the nitrogen atom. In addition, hydrocarbons having an anthracene structural motif without heteroatoms produced higher or equal percentages of protonated ions compared to that achieved with molecular ions. The results of this study can be used to improve the analyses of aromatic compounds.

Proton Affinities of Organocatalysts Derived from Pyridine N-oxide

Czech Academy of Sciences Publication Activity Database

Váňa, J.; Roithová, J.; Kotora, Martin; Beran, Pavel; Rulíšek, Lubomír; Kočovský, Pavel

2014-01-01

Roč. 87, č. 4 (2014), s. 349-356 ISSN 0011-1643 R&D Projects: GA ČR(CZ) GA14-31419S Grant - others:GA ČR(CZ) GAP207/11/0587 Institutional support: RVO:61388963 Keywords : density functional theory * isodesmic reactions * kinetic method * mass spectrometry * organocatalysis * proton affinity * superbases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.728, year: 2014

A Mechanistic Study of the Influence of Proton Transfer Processes on the Behavior of Thiol/Disulfide Redox Couples

National Research Council Canada - National Science Library

Shouji, Eiichi

1998-01-01

.... In order to elucidate the influence of proton transfers on these redox processes, special attention has been paid to the influence of various bases, including triethylamine, pyridine, 3-chloro...

Heavy ion storage rings

International Nuclear Information System (INIS)

Schuch, R.

1987-01-01

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

Crystal structure of chlorido(2-{1-[2-(4-chlorophenylhydrazin-1-ylidene-κN]ethyl}pyridine-κN(η5-pentamethylcyclopentadienylrhodium(III chloride

Directory of Open Access Journals (Sweden)

Neelakandan Devika

2015-03-01

Full Text Available The cation of the title compound, [Rh(η5-C5Me5Cl(C13H12ClN3]Cl, adopts a typical piano-stool geometry. The complex is chiral at the metal and crystallizes as a racemate. Upon coordination, the hydrazinylidenepyridine ligand is non-planar, an angle of 54.42 (7° being observed between the pyridine ring and the aromatic ring of the [2-(4-chlorophenylhydrazin-1-ylidene]ethyl group. In the crystal, a weak interionic N—H...Cl hydrogen bond is observed.

Instability of equatorial protons in Jupiter's mid-magnetosphere

International Nuclear Information System (INIS)

Northrop, T.G.; Schardt, A.W.

1980-01-01

Two different models for the distribution function are fit to the Jovian protons seen by Pioneer 10 inbound. The models reproduce the observed energy and angular distributions. These models are then used to assess the collisionless mirror instability. Because of the pancake proton angular distributions in the equatorial ring current region, the ring current particle population appears to be mirror unstable at times, with instability growth rates of approx.10 min. Such a time is consistent with observed proton flux autocorrelation times. An instability such as this (there are other candidates) may be responsible for the previously established proton flux flowing parallel to the magnetic field away from the equatorial region

1H and 13C NMR coordination-induced shifts in a series of tris(α-diimine)ruthenium(II) complexes containing pyridine, pyrazine, and thiazole moieties

International Nuclear Information System (INIS)

Orellana, G.; Ibarra, C.A.; Santoro, J.

1988-01-01

1 H and 13 C NMR chemical shifts of a series of ruthenium(II) tris chelates containing the heterocyclic ligands 2,2'-bipyridine, 2-(2-pyridyl)thiazole, 2-(2-pyrazyl)thiazole, and 2,2'-bithiazole are reported and compared to those of the corresponding free ligands. Calculated coordination-induced shifts (CIS, δ complexed - δ free ) range from +0.41 to -1.00 ppM for 1 H and from +5.8 to -3.7 ppM for 13 C nuclei. These values are discussed on the basis of the various effects (charge perturbation and field interactions) that arise upon chelation: electronic σ-donation to the metallic center via the nitrogen lone pair, d-π* back-donation to the ligand, van der Waals interactions, and magnetic anisotropy of the spectator ligands. Semiquantitative values of each effect at the different positions have been proposed, taking theoretical calculations of steric and anisotropic contributions as the starting point. Shielding van der Waals interaction between proximate atoms influences only the H(3') CIS of six-membered moieties, but to a very low extent (<0.15 ppM). Magnetic anisotropy of proximate ring currents practically determines the CIS of the α positions for all the complexed ligands examined (upfield shifts from -0.8 to -1.0 ppm), has a lower influence on external β positions (< 0.2 ppM), and is negligible for γ-protons. σ-donation deshields all the positions, its contribution increasing as protons separate from the coordinated nitrogen atom (up to 0.4 ppM). Π-back-bonding is a weaker effect (< 0.2 ppM upfield contribution) that operates mainly on the γ position of the pyridine and α and β positions of the pyrazine rings. 36 refs., 3 figs., 4 tabs

Crystal structure of bis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]bis(thiocyanato-κScopper(II

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Abdelhakim Laachir

2016-08-01

Full Text Available The mononuclear title complex, [Cu(SCN2(C12H8N4S2], was obtained by the reaction of 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole and potassium thiocyanate with copper(II chloride dihydrate. The copper cation lies on an inversion centre and displays an elongated octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by the S atoms of two thiocyanate anions. The thiadiazole and the pyridyl rings linked to the metal are approximately coplanar, with a maximum deviation from the mean plane of 0.190 (2 Å. The cohesion of the crystal structure is ensured by weak C—H...N hydrogen bonds and π–π interactions between parallel pyridyl rings of neighbouring molecules [centroid-to-centroid distance = 3.663 (2 Å], leading to a three-dimensional network.

Storage rings, internal targets and PEP

International Nuclear Information System (INIS)

Spencer, J.E.

1986-11-01

Storage rings with internal targets are described, using PEP as an example. The difference between electrons and heavier particles such as protons, antiprotons, and heavy ions is also discussed because it raises possibilities of bypass insertions for more exotic experiments. PEP is compared to other rings in various contexts to verify the assertion that it is an ideal ring for many fundamental and practical applications that can be carried on simultaneously

Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6cadmate(II dihydrate

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Najmeh Firoozi

2008-10-01

Full Text Available In the title compound, (C4H14N2[Cd(C7H3NO42]·2H2O, the CdII ion is coordinated by four O atoms [Cd—O = 2.2399 (17–2.2493 (17 Å] and two N atoms [Cd—N = 2.3113 (15 and 2.3917 (15 Å] from two tridentate pyridine-2,6-dicarboxylato ligands in a distorted octahedral geometry. The uncoordinated water molecules are involved in O—H...O and N—H...O hydrogen bonds, which contribute to the formation of a three-dimensional supramolecular structure, along with π–π stacking interactions [centroid–centroid distances of 3.5313 (13 and 3.6028 (11 Å between the pyridine rings of neighbouring dianions].

Tetrel, Chalcogen, and Charge-Assisted Hydrogen Bonds in 2-((2-Carboxy-1-(substituted-2-hydroxyethylthio Pyridin-1-ium Chlorides

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Firudin I. Guseinov

2017-10-01

Full Text Available Reaction of 2-chloro-2-(diethoxymethyl-3-substitutedoxirane or 1-chloro-1-(substituted -3,3-diethoxypropan-2-one with pyridine-2-thiol in EtOH at 25 °C yields 3-(diethoxymethyl-3-hydroxy-2-substituted-2,3-dihydrothiazolo[3,2-a]pyridin-4-ium chlorides, which subsequently, in MeCN at 85°C, transforms into ring-opening products, 2-((2-carboxy-1-(substituted -2-hydroxyethylthiopyridin-1-ium chlorides. The tetrel (C···O and chalcogen (S···O bonds are found in the structures of 5 and 6, respectively. Compound 6 is also present in halogen bonding with a short O···Cl distance (3.067 Å. Both molecules are stabilized in crystal by tetrel, chalcogen, and multiple charge-assisted hydrogen bonds.

2-[(2,4,4,6,6-Pentachloro-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinin-2-ylazanidyl]pyridinium

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Safaa A. Ahmed

2012-02-01

Full Text Available The title compound, C5H5Cl5N5P3, crystallizes as a zwitterion in which the pyridine N atom is protonated. An S(6 ring motif is formed via an intramolecular C—H...N hydrogen bond. The triazatriphosphinine ring adopts an envelope conformation, with one N atom displaced by 0.145 (1 Å from the other atoms. In the crystal, N—H...N and C—H...N hydrogen bonds link the molecules into centrosymmetric dimers containing one R22(7 ring motif and two R22(8 ring motifs.

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

Directory of Open Access Journals (Sweden)

Maxym O. Plutenko

2012-12-01

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

High intensity proton accelerator and its application (Proton Engineering Center)

International Nuclear Information System (INIS)

Tanaka, Shun-ichi

1995-01-01

A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, Spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

Proposal for construction of a proton--proton storage accelerator facility (Isabelle)

International Nuclear Information System (INIS)

1975-06-01

A proposal is made for the construction of proton storage rings at the Brookhaven Alternating Gradient Synchrotron (AGS) using superconducting magnets for which much of the technology has already been developed. This proton-proton colliding beam facility, ''ISABELLE,'' will provide large increases in both the center-of-mass energy and the luminosity, key machine parameters for high energy physics. The physics potential and the general description of the facility are discussed in detail, and the physical plant layout, a cost estimate and schedule, and future options are given.(U.S.)

Synthesis, crystal growth and characterization of bioactive material: 2- Amino-1H-benzimidazolium pyridine-3-carboxylate single crystal- a proton transfer molecular complex

Science.gov (United States)

Fathima, K. Saiadali; Kavitha, P.; Anitha, K.

2017-09-01

The 1:1 molecular adducts 2- Amino-1H-benzimidazolium pyridine-3-carboxylate (2ABPC) was synthesized and grown as single crystal where 2-aminobenzimidazole (ABI) acts as a donor and nicotinic acid (NA) acts as an acceptor. The presence of proton and carbon were predicted using 1H and 13C NMR spectral analysis. The molecular structure of the crystal was elucidated by subjecting the grown crystals to the single crystal x-ray diffraction analysis and was refined by full matrix least-squares method to R = 0.038 for 2469 reflections. The vibrational modes of functional group have been studied using FTIR and Raman spectroscopic analysis. The UV-Vis spectrum exhibited a visible band at 246 nm for 2ABPC due to the nicotinate anion of the molecule. Further, the antimicrobial activity of 2ABPC complex against B. subtilis, klebsiella pneumonia, Pseudomonas eruginos and E. coli pathogens was investigated. Minimum Inhibitory Concentration (MIC) for this crystal was obtained using UV spectrometer against MRSA pathogen. It was found that the benzimidazole with aminogroup at position 2 increases the general antimicrobial activities of 2ABPC crystal.

Second law analysis of the helium refrigerators for the HERA proton magnet ring

International Nuclear Information System (INIS)

Ziegler, B.O.

1986-01-01

Each of the three refrigerators for the HERA proton magnet ring must provide 6.775 kW of refrigeration at 4.3 0 K plus 20.5 g/s of helium at 2.5 bar and 4.5 0 K for leads cooling and 20 kW of refrigeration at 40-80 0 K for shield cooling. The capital cost of large refrigerators is small compared with operating costs. Therefore the refrigeration process was analysed on the basis of exergy. This means the irreversibility of each component is expressed as power input into the plant. The process realised consists of the turbine cycle, divided into two streams with 5 gas bearing turbines all together, and the Joule Thomson cycle. Special attention was paid to the cold end of the plant. The optimization resulted in a new configuration with two turboexpanders running in parallel on different temperature levels

Calorimetric investigations of hydrogen bonding in binary mixtures containing pyridine and its methyl-substituted derivatives. II. The dilute solutions of methanol and 2-methyl-2-propanol

International Nuclear Information System (INIS)

Marczak, Wojciech; Heintz, Andreas; Bucek, Monika

2004-01-01

Enthalpies of solution of methanol and 2-methyl-2-propanol (tert-butanol) in pyridine and its methyl derivatives were investigated in the range of mole fractions of alcohol x≤0.02 at temperature 298.15 K by a titration calorimeter. Dissolution of methanol is an exothermic process, with heat effects very close to those for water reported in part I of this study. The negative enthalpy of solution increases in the following order: pyridine < 3-methylpyridine < 4-methylpyridine < 2-methylpyridine < 2,6-dimethylpyridine < 2,4,6-trimethylpyridine. Positive enthalpies of solution of 2-methyl-2-propanol increase as follows: 2-methylpyridine < 2,4,6-trimethylpyridine < 4-methylpyridine < 2,6-dimethylpyridine < 3-methylpyridine < pyridine. The propensity of pyridine derivatives to hydrogen bonding is enhanced by the ortho effect. Methyl groups are probably too small to prevent the nitrogen atom in the pyridine ring from hydrogen bonding. However, spacious hydrocarbon group in 2-methyl-2-propanol molecule makes the bonding difficult for 2,6-dimethylpyridine and 2,4,6-trimethylpyridine, thus the number of O-H···N bonds is smaller than that in the solutions of methanol or water. The two latter seem to be very close to each other

MEIC Proton Beam Formation with a Low Energy Linac

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2015-09-01

The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

Influence of methoxy- and nitro-substitutions in the aromatic ring on proton donation ability in hydrogen bond and on the amino group parameters of free and H-bonded molecules of 2-aminopyrimidine

Science.gov (United States)

Borisenko, V. E.; Krekov, S. A.; Fomenko, M. Yu.; Koll, A.; Lipkovski, P.

2008-06-01

Amino- and imino- forms of pyrimidine are widely presented as part of antibiotics, corrective medications for heart failures and metabolic stimulators. Hydrogen bonding is one of the fundamental interactions between biologically active molecules. This type of interactions provides flexibility, speed and variety of the biochemical processes. Proton donation properties of aminopyrimidines significantly depend on the position, number and kind of the substituent in its aromatic ring. In present work we studied the influence of the methoxy- and nitro-substitutions in the phenyl radical of pyridine and pyrimidine cycles on the proton donation ability of the amino group in hydrogen bonds as well as on its geometrical, force, electro-optical and thermodynamical characteristics in free and H-bonded (1:1 and 1:2, with various proton acceptors) molecules of primary aromatic amines. Acetonitrile, dioxane, tetrahydrofourane, dimethylformamide, dimethylsulfoxide and hexamethylphosphoramide (whose proton accepting properties vary within a wide range) were used as proton acceptors in our research. In the region of the amino group stretching and deformation vibrations the IR spectra of free and H-bonded (1:1) molecules of 2-amino-4,6-dimethoxy- and 2-amino-5-nitropyrimidine were studied in complexes with proton acceptors in CCl 4 within the temperature range 288-328 K. The spectra of 1:2 complexes were studied in undiluted aprotic solvents. The following spectral characteristics of absorption bands in amino group stretching vibrations were determined: M(0) (zero spectral moment, integrated intensity B); M(1) (first spectral moment, band "centre of gravity"); effective half width, related to the second central moment (Δ ν1/2) eff = 2( M(2)) 1/2, frequencies of the deformation vibrations δ(HNH) of free and H-bonded molecules. It was shown that changes of the absorption band spectral characteristics of the amino group stretching and deformation vibrations in the analyzed

Energetic Proton Spectra Measured by the Van Allen Probes

Science.gov (United States)

Summers, Danny; Shi, Run; Engebretson, Mark J.; Oksavik, Kjellmar; Manweiler, Jerry W.; Mitchell, Donald G.

2017-10-01

We test the hypothesis that pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves can limit ring current proton fluxes. For two chosen magnetic storms, during 17-20 March 2013 and 17-20 March 2015, we measure proton energy spectra in the region 3 ≤ L ≤ 6 using the RBSPICE-B instrument on the Van Allen Probes. The most intense proton spectra are observed to occur during the recovery periods of the respective storms. Using proton precipitation data from the POES (NOAA and MetOp) spacecraft, we deduce that EMIC wave action was prevalent at the times and L-shell locations of the most intense proton spectra. We calculate limiting ring current proton energy spectra from recently developed theory. Comparisons between the observed proton energy spectra and the theoretical limiting spectra show reasonable agreement. We conclude that the measurements of the most intense proton spectra are consistent with self-limiting by EMIC wave scattering.

UV-VIS-spectroscopical investigations of the green solutions of nitrogen triiodide-1-pyridine in pyridine

International Nuclear Information System (INIS)

Kerbachi, R.; Minkwitz, R.; Engelhardt, U.

1984-01-01

Solid, crystalline nitrogen triiodide-1-pyridine has a polymeric structure similar to that of nitrogen triiodide-1-ammonia consisting of NI 4 tetrahedra linked to chains by common vertices. The solubility of both compounds in liquid ammonia is accomplished by a degradation of the chains involving protolysis equilibria with monoiodamine. UV-VIS-spectra of the green solutions of NI 3 pyridine in the aprotic solvent pyridine between -30 and -16 0 C and Raman-spectra of these solutions at -30 0 C or quenched with liquid nitrogen at -196 0 C show, that the chains are retained here at least to some extent. The solutions are instable even at low temperatures and decompose in a first order reaction yielding nitrogen and iodine. The halflife period at -16 0 C is 5 hours, at -30 0 C 20 hours. (author)

An analysis of the long-term stability of the particle dynamics in hadron storage rings

International Nuclear Information System (INIS)

Bruening, O.S.

1994-05-01

This thesis extends the stability analysis of the particle motion in a storage ring and estimates the diffusion rates well inside the dynamic aperture. The calculation of the drift and diffusion coefficients focuses on an application to the proton storage ring in HERA, where the proton beam lifetime drops considerably after the proton and electron beams are brought to collision. The analysis shows that the combined effect of slow and fast modulation frequencies leads to an increased emittance growth in the storage ring. HERA the slow frequency components are caused by ground motion in the HERA tunnel and the fast frequency components by ripples in the power supplies. The thesis provides upper limits for the modultion depths of a fast tune modulation which result in tolerable growth rates for the proton emittance. The analytically calculated drift coefficients agree numerical simulations for the particle dynamics. A comparison of the calculated drift coefficients with those measured in the HERA proton storage ring shows that the analyzed mechanism can lead to growth rates of the same order of magnitude as the ones measured during the luminosity operation in the HERA storage ring. Analytical estimates for the proton growth rates predict a high sensitivity to the particle diffusion on the frequency components of the fast fast tune modulation. This prediction was confirmed by a subsequent modulation experiment in the proton storage ring of HERA, where an external tune modulation with fast frequency components led to a drastic increase in the growth rates

Proton magnetic resonance study of the influence of chemical modification, mutation, quaternary state, and ligation state on dynamic stability of the heme pocket in hemoglobin as reflected in the exchange of the proximal histidyl ring labile proton

International Nuclear Information System (INIS)

Han, K.H.; La Mar, G.N.; Nagai, K.

1989-01-01

Proton nuclear magnetic resonance spectroscopy has been utilized to investigate the rates of exchange with deuterium of the proximal histidyl ring protons in a series of chemically modified and mutated forms of Hb A. Differences in rates of exchange are related to differences in the stability of the deformed or partially unfolded intermediates from which exchange with bulk solvent takes place. Each modified/mutated Hb exhibited kinetic subunit heterogeneity in the reduced ferrous state, with the alpha subunit exhibiting faster exchange than the beta subunit. Modification or mutation resulted in significant increases in the His F8 ring NH exchange rates primarily for the affected subunit and only if the modification/mutation occurs at the allosterically important alpha 1 beta 2 subunit interface. Moreover, this enhancement in exchange rate is observed primarily in that quaternary state of the modified/mutated Hb in which the modified/substituted residue makes the intersubunit contact. This confirms the importance of allosteric constraints in determining the dynamic properties of the heme pocket. Using modified or mutated Hbs that can switch between the alternate quaternary states within a given ligation state or ligate within a given quaternary state, we show that the major portion of the enhanced exchange rate in R-state oxy Hb relative to T-state deoxy Hb originates from the quaternary switch rather than from ligation. However, solely ligation effects are not negligible. The exchange rates of the His F8 ring labile protons increase dramatically upon oxidizing the iron to the ferric state, and both the subunit kinetic heterogeneity and the allosteric sensitivity to the quaternary state are essentially abolished

Pyridine-Based Conjugated Polymers: Photophysical Properties and Light- Emitting Diodes

National Research Council Canada - National Science Library

Epstein, A

1997-01-01

We study the photophysical properties of the pyridine-based polymers poly (p-pyridyl vinylene) (PPyV) and poly (p-pyridine) (PPy). The primary photoexcitations in the pyridine-based polymers are singlet excitons...

SO ₂ Phototriggered Crystalline Nanomechanical Transduction of Aromatic Rotors in Tosylates: Rationalization via Photocrystallography of [Ru(NH ₃ ) ₄ SO ₂ X]tosylate ₂ (X = pyridine, 3-Cl-pyridine, 4-Cl-pyridine)

Energy Technology Data Exchange (ETDEWEB)

Sylvester, Sven O.; Cole, Jacqueline M.; Waddell, Paul G.; Nowell, Harriott; Wilson, Claire

2014-07-24

Thermally-reversible solid-state linkage SO2 photoisomers of three complexes in the [Ru(NH3)4SO2X]tosylate2 family are captured in their metastable states using photocrystallography, where X = pyridine (1), 3-Cl-pyridine (2) and 4-Cl-pyridine (3). This photoisomerism only exists in the single-crystal form; accordingly, the nature of the crystalline environment surrounding the photo-active species controls its properties. In particular, the structural role of the tosylate anion needs to be understood against possible chemical influences due to varying the trans ligand, X. The photo-excited geometries, photoconversion levels and thermal stabilities of the photoisomers that form in 1-3 are therefore studied. 1 and 2 yield two photo-isomers at 100 K: the O-bound end-on n1-SO2 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry (MS1) configuration and the side-bound n2-SO2 (MS2), while 3 only exhibits the more thermally stable MS2 geometry. The decay kinetics of the MS2 geometry for 1-3 demonstrate that the greater the free volume of the GS SO2 ligand for a given counterion, the greater the MS2 thermal stability. Furthermore, a rationalization is sought for the SO2 phototriggered molecular rotation of the phenyl ring in the tosylate anion; this is selectively observed in 2, manifesting as nanomechanical molecular transduction. This molecular transduction was not observed in 1, despite the presence of the MS1 geometry due to the close intermolecular interactions between the MS1 SO2 and the neighbouring tosylate ion. The decay of this anionic molecular rotor in 2, however, follows a non-traditional decay pathway, as determined by time-resolved crystallographic analysis; this contrasts with the well-behaved first-order kinetic decay of its MS1 SO2 phototrigger.

Crystal structure and DFT study of (E-4-[({4-[(pyridin-2-ylmethylideneamino]phenyl}aminomethyl]phenol

Directory of Open Access Journals (Sweden)

Md. Serajul Haque Faizi

2018-03-01

Full Text Available In the title Schiff base compound, C19H17N3O, the configuration about the C=N bond is E. The molecule is non-planar, with the phenolic and pyridine rings being inclined to the central benzene ring by 56.59 (4 and 15.13 (14°, respectively. In the crystal, molecules are linked by pairs of O—H...N hydrogen bonds, forming inversion dimers. The dimers are connected to neighbouring dimers by N—H...O hydrogen bonds and C—H...π interactions, forming layers parallel to the bc plane. The layers are linked by offset π–π interactions [intercentroid distance = 3.779 (2 Å], forming a three-dimensional supramolecular structure. Quantum chemical calculations of the molecule are in good agreement with the solid-state structure.

Tetrakis(μ2-2,2-dimethylpropanoato-κ2O,O′bis[(pyridine-κNcopper(II]: a monoclinic polymorph

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Lailatun Nazirah Ozair

2010-05-01

Full Text Available The structure of the dinuclear title complex, [Cu2(C5H9O24(C5H5N2], represents a monoclinic polymorph of the previously reported triclinic form [Blewett et al. (2006. Acta Cryst. E62, m420–m422]. Each carboxylate group is bidentate bridging and the distorted octahedral geometry about each CuII atom is completed by a pyridine N atom and the other Cu atom [Cu...Cu = 2.6139 (7 Å]. In the crystal, molecules are connected into supramolecular chains via π–π interactions formed by the pyridine rings [centroid–centroid distance = 3.552 (3 Å] and these are connected into a two-dimensional array in the ac plane by C—H...π contacts. One of the tert-butyl groups is disordered over two orientations in a 0.734 (6:0.266 (6 ratio.

New developments on the e-p instability at the Los Alamos Proton Storage Ring

International Nuclear Information System (INIS)

Macek, R.J.; Browman, A.; Fitzgerald, D.H.; McCrady, R.; Plum, M.; Spickermann, T.

2001-01-01

New results are reported from an R and D program aimed greater understanding and control of the e-p instability observed at the Los Alamos Proton Storage Rings (PSR). Numerous characteristics of the electron cloud for both stable and unstable beams in PSR were measured with ANL electron analyzers and various collection plates. Strong suppression of the electron flux density by TiN coating of the vacuum chamber in a straight section was also observed, thereby confirming an essential role for secondary emission at the walls. Landau Damping by a variety of techniques including higher rf voltage, transverse coupling, multipole fields in the lattice, and the use of inductive inserts has been effective in controlling the e-p instability. By these methods, the instability threshold has been raised significantly to 9.7 micro Coulombs per stored pulse. (author)

Octa­akis(4-amino­pyridine)-1κ4 N 1,2κ4 N 1-aqua-2κO-μ-carbonato-1:2κ3 O,O′:O′′-dinickel(II) dichloride penta­hydrate

Science.gov (United States)

Fun, Hoong-Kun; Sinthiya, A; Jebas, Samuel Robinson; Ravindran Durai Nayagam, B.; Alfred Cecil Raj, S.

2008-01-01

In the title compound, [Ni2(CO3)(C5H6N2)8(H2O)]Cl2·5H2O, one of the the NiII ions is six-coordinated in a distorted octa­hedral geometry, with the equatorial plane defined by four pyridine N atoms from four amino­pyridine ligands, the axial positions being occupied by one water O and a carbonate O atom. The other NiII ion is also six-coordinated, by four other pyridine N atoms from four other amino­pyridine ligands and two carbonate O atoms to complete a distorted octa­hedral geometry. In the crystal structure, mol­ecules are linked into an infinite three-dimensional network by O—H⋯O, N—H⋯Cl, N—H⋯O, O—H⋯N, C—H⋯O, C—H⋯N and C/N—H⋯π inter­actions involving the pyridine rings. PMID:21580879

Status of experimental studies of electron cloud effects at the Los Alamos proton storage ring

International Nuclear Information System (INIS)

Macek, R.J.; Browman, A.A.; Borden, M.J.; Fitzgerald, D.H.; McCrady, R.C.; Spickermann, T.J.; Zaugg, T.J.

2004-01-01

Various electron cloud effects (ECE) including the two-stream (e-p) instability at the Los Alamos Proton Storage Ring (PSR) have been studied extensively for the past five years with the goal of understanding the phenomena, mitigating the instability and ultimately increasing beam intensity. The specialized diagnostics used in the studies are two types of electron detectors, the retarding field analyzer and the electron sweepmg detector - which have been employed to measure characteristics of the electron cloud as functions of time, location in the ring and various influential beam parameters - plus a short stripline beam position monitor used to measure high frequency motion of the beam centroid. Highlights of this research program are summarized along with more detail on recent results obtained since the ECLOUD'02 workshop. Recent work mcludes a number of parametric studies of the various factors that affect the electron cloud signals, studies of the sources of initial or 'seed' electrons, additional observations of electron cloud dissipation after the beam pulse is extracted, studies of the 'first pulse instability' issue, more data on electron suppression as a cure for the instability, and observations of the effect of a one-turn weak kick on intense beams in the presence of a significant electron cloud.

(E)-6-Amino-1,3-dimethyl-5-[(pyridin-2-yl-methyl-idene)amino]-pyrimidine-2,4(1H,3H)-dione.

Science.gov (United States)

Booysen, Irvin; Hlela, Thulani; Ismail, Muhammed; Gerber, Thomas; Hosten, Eric; Betz, Richard

2011-09-01

In the title compound, C(12)H(13)N(5)O(2), a Schiff-base-derived chelate ligand, the non-aromatic heterocycle and its substituents essentially occupy one common plane (r.m.s. of fitted non-H atoms = 0.0503 Å). The N=C bond is E-configured. Intra-cyclic angles in the pyridine moiety cover the range 117.6 (2)-124.1 (2)°. Intra- and inter-molecular N-H⋯N and N-H⋯O hydrogen bonds are observed in the crystal structure, as are intra- and inter-molecular C-H⋯O contacts which, in total, connect the mol-ecules into a three-dimensional network. The shortest ring-centroid-to-ring-centroid distance of 3.5831 (14) Å is between the two different types of six-membered rings.

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

Science.gov (United States)

Sagar, Belakavadi K; Harsha, Kachigere B; Yathirajan, Hemmige S; Rangappa, Kanchugarakoppal S; Rathore, Ravindranath S; Glidewell, Christopher

2017-03-01

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Ring current instabilities excited by the energetic oxygen ions

International Nuclear Information System (INIS)

Kakad, A. P.; Singh, S. V.; Lakhina, G. S.

2007-01-01

The ring current instabilities driven by the energetic oxygen ions are investigated during the magnetic storm. The electrons and protons are considered to have Maxwellian distributions, while energetic oxygen ions are having loss-cone distribution. Dispersion relation for the quasielectrostatic modes with frequencies ω>ω cp (proton cyclotron frequency) and propagating obliquely to the magnetic field is obtained. Dispersion relation is studied numerically for the storm time ring current parameters and it is found that these instabilities are most prominent during intense storms when the oxygen ions become the dominant constituents of the ring current plasma. For some typical storm-time ring current parameters, these modes can produce quasielectrostatic noise in the range of 17-220 Hz, thus providing a possible explanation of the electrostatic noise observed at the inner boundary of the ring current during magnetic storms. Further, these modes can attain saturation electric fields of the order of 100-500 μV/m, and therefore, are expected to scatter O + ions into the loss-cone giving rise to their precipitation into the atmosphere, thus contributing to the ring current decay

(Pyridine-2-aldoximato-κ2N,N′bis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III

Directory of Open Access Journals (Sweden)

Bimal Chandra Singh

2013-03-01

Full Text Available In the title complex, [Ir(C11H8N2(C6H5N2O], the octahedrally coordinated IrIII atom is bonded to two 2-(pyridin-2-ylphenyl ligands, through two phenyl C and two pydidine N atoms, and to one pyridine-2-aldoxime ligand through a pyridine N and an oxime N atom. The oxime O atom of the aldoxime unit forms intermolecular C—H...O hydrogen bonds, which result in a two-dimensional hydrogen-bonded polymeric network parallel to (100. C—H...π interactions are also observed.

Diaquabis(pyridine-2-carboxylato-κ2N,Omanganese(II dimethylformamide hemisolvate

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Irina A. Golenya

2011-11-01

Full Text Available There are two crystallographically independent complex molecules with very similar geometries in the unit cell of the title compound, [Mn(C6H4NO22(H2O2]·0.5C3H7NO. The central ion is situated in a distorted octahedral environment of two N- and four O-donor atoms from two pyridine-2-carboxylate ligands and two cis-disposed water molecules. The carboxylate ligands are coordinated in a chelate fashion with the formation of two five-membered rings. In the crystal, the complex molecules are connected by O—H...O hydrogen bonds between the coordinated water molecules and the uncoordinated carboxylate O atoms, thus forming hydrogen-bonded walls disposed perpendicularly to the bc plane.

An experiment to study CP violation in the B system using an internal target at the HERA proton ring

International Nuclear Information System (INIS)

Hofmann, W.

1993-03-01

A group of physicists centered around the ARGUS collaboration got interested in hadron accelerators as a prolific source of B hadrons. The group is presently studying the option of a major-B-physics experiment to be performed at the HERA proton storage ring in fixed target mode using an internal target. Basic goal of the experiment is the detection of CP violation in the 'gold plated' B 0 → J/Ψ K s decay mode, using a dedicated detector triggered on lepton pairs from J/Ψ decay. (orig./HSI)

Pyridine-induced Dimensionality Change in Hybrid Perovskite Nanocrystals

KAUST Repository

Ahmed, Ghada H.; Yin, Jun; Bose, Riya; Sinatra, Lutfan; Alarousu, Erkki; Yengel, Emre; AlYami, Noktan; Saidaminov, Makhsud I.; Zhang, Yuhai; Hedhili, Mohamed N.; Bakr, Osman; Bredas, Jean-Luc; Mohammed, Omar F.

2017-01-01

of pyridine during the synthesis of methylammonium lead bromide (MAPbBr) perovskite nanocrystals can transform three-dimensional (3D) cubes into two-dimensional (2D) nanostructures. Density functional theory (DFT) calculations show that pyridine preferentially

Propane-1,3-diaminium–2-carboxypyridine-6-carboxylate–pyridine-2,6-dicarboxylic acid–water (1/2/2/8

Directory of Open Access Journals (Sweden)

Hossein Aghabozorg

2008-01-01

Full Text Available The title proton-transfer compound, C3H12N22+·2C7H4NO4−·2C7H5NO4·8H2O or (pnH2(pydcH2.2(pydcH2·8H2O, was obtained by the reaction of pyridine-2,6-dicarboxylic acid (pydcH2 and propane-1,3-diamine (pn in aqueous solution. Both neutral and monoanionic forms of the diacid are observed in the crystal structure. The negative charge of two monoanions is balanced by the dicationic propane-1,3-diaminium species. In addition, considerable π–π stacking interactions between the aromatic rings of the (pydcH− and (pydcH2 fragments [with centroid–centroid distances of 3.5108 (11–3.5949 (11 Å] are observed. The most important feature of this crystal structure is the presence of a large number of O—H...O, O—H...N, N—H...O, N—H...N, C—H...O and C—H...N hydrogen bonds, with D...A ranging from 2.445 (2 to 3.485 (3 Å. These interactions as well as ion pairing and π–π stacking connect the various fragments into a supramolecular structure.

SPL-based Proton Driver for a nu-Factory at CERN

CERN Document Server

Benedetto, E; Garoby, R; Meddahi, M

2010-01-01

The conceptual design and feasibility studies for a nu-Factory Proton Driver based on the CERN Superconducting Proton Linac (SPL) have been com- pleted. In the proposed scenario, the 4 MW proton beam (H- beam) is acceler- ated with the upgraded High Power (HP)-SPL to 5 GeV, stored in an accumu- lator ring and Þnally transported to a compressor ring, where bunch rotation takes place, in order to achieve the speciÞc time structure. We here summa- rize the choices in terms of lattice, magnet technology and RF manipulations in the two rings. The possible critical issues, such as heating of the foil for the charge-exchange injection, space-charge problems in the compressor and beam stability in the accumulator ring, have been addressed and are shown not to be show-stoppers. The analysis focuses on the baseline scenario, consider- ing 6 bunches in the accumulator, and preliminary studies are discussed for the option of 3 or a single bunch per burst.

Zirconium and Titanium Propylene Polymerization Precatalysts Supported by a Fluxional C 2 -Symmetric Bis(anilide)pyridine Ligand

KAUST Repository

Tonks, Ian A.

2012-03-12

Titanium and zirconium complexes supported by a bis(anilide)pyridine ligand (NNN = pyridine-2,6-bis(N-mesitylanilide)) have been synthesized and crystallographically characterized. C 2-symmetric bis(dimethylamide) complexes were generated from aminolysis of M(NMe 2) 4 with the neutral, diprotonated NNN ligand or by salt metathesis of the dipotassium salt of NNN with M(NMe 2) 2Cl 2. In contrast to the case for previously reported pyridine bis(phenoxide) complexes, the ligand geometry of these complexes appears to be dictated by chelate ring strain rather than metal-ligand π bonding. The crystal structures of the five-coordinate dihalide complexes (NNN)MCl 2 (M = Ti, Zr) display a C 1-symmetric geometry with a stabilizing ipso interaction between the metal and the anilido ligand. Coordination of THF to (NNN)ZrCl 2 generates a six-coordinate C 2-symmetric complex. Facile antipode interconversion of the C 2 complexes, possibly via flat C 2v intermediates, has been investigated by variable-temperature 1H NMR spectroscopy for (NNN)MX 2(THF) n (M = Ti, Zr; X = NMe 2, Cl) and (NNN)Zr(CH 2Ph) 2. These complexes were tested as propylene polymerization precatalysts, with most complexes giving low to moderate activities (10 2-10 4 g/(mol h)) for the formation of stereoirregular polypropylene. © 2012 American Chemical Society.

Halo and space charge issues in the SNS Ring

International Nuclear Information System (INIS)

Fedotov, A.V.; Abell, D.T.; Beebe-Wang, J.; Lee, Y.Y.; Malitsky, N.; Wei, J.; Gluckstern, R.L.

2000-01-01

The latest designs for high-intensity proton rings require minimizing beam-induced radioactivation of the vacuum chamber. Although the tune depression in the ring is much smaller than in high-intensity linacs, space-charge contributions to halo formation and, hence, beam loss may be significant. This paper reviews our current understanding of halo formation issues for the Spallation Neutron Source (SNS) accumulator ring

Halo and space charge issues in the SNS Ring

Energy Technology Data Exchange (ETDEWEB)

Fedotov, A.V.; Abell, D.T.; Beebe-Wang, J.; Lee, Y.Y.; Malitsky, N.; Wei, J.; Gluckstern, R.L.

2000-06-30

The latest designs for high-intensity proton rings require minimizing beam-induced radioactivation of the vacuum chamber. Although the tune depression in the ring is much smaller than in high-intensity linacs, space-charge contributions to halo formation and, hence, beam loss may be significant. This paper reviews our current understanding of halo formation issues for the Spallation Neutron Source (SNS) accumulator ring.

Which hydrogen atom of toluene protonates PAH molecules in (+)-mode APPI MS analysis?

Science.gov (United States)

Ahmed, Arif; Ghosh, Manik Kumer; Choi, Myung Chul; Choi, Cheol Ho; Kim, Sunghwan

2013-03-01

A previous study (Ahmed, A. et al., Anal. Chem. 84, 1146-1151( 2012) reported that toluene used as a solvent was the proton source for polyaromatic hydrocarbon compounds (PAHs) that were subjected to (+)-mode atmospheric-pressure photoionization. In the current study, the exact position of the hydrogen atom in the toluene molecule (either a methyl hydrogen or an aromatic ring hydrogen) involved in the formation of protonated PAH ions was investigated. Experimental analyses of benzene and anisole demonstrated that although the aromatic hydrogen atom of toluene did not contribute to the formation of protonated anthracene, it did contribute to the formation of protonated acridine. Thermochemical data and quantum mechanical calculations showed that the protonation of anthracene by an aromatic ring hydrogen atom of toluene is endothermic, while protonation by a methyl hydrogen atom is exothermic. However, protonation of acridine by either an aromatic ring hydrogen or a methyl hydrogen atom of toluene is exothermic. The different behavior of acridine and anthracene was attributed to differences in gas-phase basicity. It was concluded that both types of hydrogen in toluene can be used for protonation of PAH compounds, but a methyl hydrogen atom is preferred, especially for non-basic compounds.

Riboflavin Production during Growth of Micrococcus luteus on Pyridine †

OpenAIRE

Sims, Gerald K.; O'Loughlin, Edward J.

1992-01-01

Micrococcus luteus produced 29 μM riboflavin during growth on 6.5 mM pyridine but not during growth on other substrates. On the basis of the results of radiolabelling studies, riboflavin was not directly synthesized from pyridine. Pyridine may interfere with riboflavin biosynthesis or elicit a general stress response in M. luteus.

In silico validation and structure activity relationship study of a series of pyridine-3-carbohydrazide derivatives as potential anticonvulsants in generalized and partial seizures.

Science.gov (United States)

Sinha, Reema; Sara, Udai Vir Singh; Khosa, Ratan Lal; Stables, James; Jain, Jainendra

2013-06-01

A series of twelve compounds (Compounds RNH1-RNH12) of acid hydrazones of pyridine-3-carbohydrazide or nicotinic acid hydrazide was synthesized and evaluated for anticonvulsant activity by MES, scPTZ, minimal clonic seizure and corneal kindling seizure test. Neurotoxicity was also determined for these compounds by rotarod test. Results showed that halogen substitution at meta and para position of phenyl ring exhibited better protection than ortho substitution. Compounds RNH4 and RNH12, were found to be the active analogs displaying 6Hz ED50 of 75.4 and 14.77 mg/kg while the corresponding MES ED50 values were 113.4 and 29.3 mg/kg respectively. In addition, compound RNH12 also showed scPTZ ED50 of 54.2 mg/kg. In the series, compound RNH12 with trifluoromethoxy substituted phenyl ring was the most potent analog exhibiting protection in all four animal models of epilepsy. Molecular docking study has also shown significant binding interactions of these two compounds with 1OHV, 2A1H and 1PBQ receptors. Thus, N-[(meta or para halogen substituted) benzylidene] pyridine-3-carbohydrazides could be used as lead compounds in anticonvulsant drug design and discovery.

Bis(5-hydroxyisophthalato-κO1bis[4-(pyridine-3-carboxamido-κN3pyridinium]copper(II tetrahydrate

Directory of Open Access Journals (Sweden)

Robert L. LaDuca

2013-12-01

Full Text Available In the title compound, [Cu(C11H10N3O2(C8H4O52]·4H2O, the CuII ion, located on a crystallographic inversion center, is coordinated in a square-planar environment by two trans-O atoms belonging to two monodentate 5-hydroxyisophthalate (hip dianions and two trans nicotinamide pyridyl N-donor atoms from monodentate protonated pendant N-(pyridin-4-ylnicotinamide (4-pnaH ligands. The protonated 4-pyridylamine groups engage in N—H+...O− hydrogen-bond donation to unligated hip O atoms to construct supramolecular chain motifs parallel to [100]. Water molecules of crystallization, situated between the chains, engage in O—H...O hydrogen bonding to form supramolecular layers and the overall three-dimensional network structure.

Degradation of pyridine and quinoline in aqueous solution by gamma radiation

Science.gov (United States)

Chu, Libing; Yu, Shaoqing; Wang, Jianlong

2018-03-01

In present work, the degradation of two N-heteroaromatic pollutants, i.e., pyridine and quinoline was investigated by gamma irradiation in the presence of TiO2 nanoparticle. The experimental results showed that quinoline has a higher degradation rate than pyridine. The removal efficiency of the pollutants, TOC and TN reached 93.0%, 11.9% and 12.0% for quinoline, 71.0%, 10.6% and 4.4% for pyridine, respectively at 7.0 kGy and initial concentration of 50 mg/L. Ammonium was detected for both pyridine and quinoline within the absorbed doses, suggesting that the organic nitrogen was transformed into ammonium. The degradation rate constant of pyridine and quinoline was increased by 1.1-1.5 times with addition of TiO2. TiO2 nanoparticles were especially effective to enhance the mineralization. The removal efficiency of TOC and TN was increased by 15-12% for pyridine and 23-25% for quinoline, respectively in the presence of 2.0 g/L TiO2. Following gamma irradiation, 2-hydroxypyridine, 3-hydroxypyridine, oxalic acid and formic acid were identified for pyridine and the hydroxyl quinoline and formic acid were detected for quinoline. Accordingly, the degradation mechanism of pyridine and quinoline by gamma irradiation was tentatively proposed.

Electric dipole moment planning with a resurrected BNL Alternating Gradient Synchrotron electron analog ring

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Richard M. Talman

2015-07-01

Full Text Available There has been much recent interest in directly measuring the electric dipole moments (EDM of the proton and the electron, because of their possible importance in the present day observed matter/antimatter imbalance in the Universe. Such a measurement will require storing a polarized beam of “frozen spin” particles, 15 MeV electrons or 230 MeV protons, in an all-electric storage ring. Only one such relativistic electric accelerator has ever been built—the 10 MeV “electron analog” ring at Brookhaven National Laboratory in 1954; it can also be referred to as the “AGS analog” ring to make clear it was a prototype for the Alternating Gradient Synchrotron (AGS proton ring under construction at that time at BNL. (Its purpose was to investigate nonlinear resonances as well as passage through “transition” with the newly invented alternating gradient proton ring design. By chance this electron ring, long since dismantled and its engineering drawings disappeared, would have been appropriate both for measuring the electron EDM and to serve as an inexpensive prototype for the arguably more promising, but 10 times more expensive, proton EDM measurement. Today it is cheaper yet to “resurrect” the electron analog ring by simulating its performance computationally. This is one purpose for the present paper. Most existing accelerator simulation codes cannot be used for this purpose because they implicitly assume magnetic bending. The new ual/eteapot code, described in detail in an accompanying paper, has been developed for modeling storage ring performance, including spin evolution, in electric rings. Illustrating its use, comparing its predictions with the old observations, and describing new expectations concerning spin evolution and code performance, are other goals of the paper. To set up some of these calculations has required a kind of “archeological physics” to reconstitute the detailed electron analog lattice design from a

Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring

International Nuclear Information System (INIS)

Macek, Robert J.; Browman, Andrew A.; Ledford, John E.; TechSource, Santa Fe; Los Alamos; Borden, Michael J.; O'Hara, James F.; McCrady, Rodney C.; Rybarcyk, Lawrence J.; Spickermann, Thomas; Zaugg, Thomas J.; Pivi, Mauro T.F.

2008-01-01

Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the 'prompt' electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the 'swept' electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100 (micro)s. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole

Electron cloud generation and trapping in a quadrupole magnet at the Los Alamos proton storage ring

Directory of Open Access Journals (Sweden)

Robert J. Macek

2008-01-01

Full Text Available Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the “prompt” electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the “swept” electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100  μs. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole.

Am and Eu extraction from acidic media by synergistic mixtures of substituted bis-tetrazolyl pyridines with chlorinated cobalt dicarbollide

International Nuclear Information System (INIS)

Smirnov, I.V.; Chirkov, A.V.; Babain, V.A.; Pokrovskaya, E.Yu.; Artamonova, T.A.

2009-01-01

Americium (Am) and europium (Eu) extraction from HNO 3 and HClO 4 media by a synergistic mixture of 2.6-bis(1-aryl-1H-tetrazol-5-yl)pyridines (ATP) with chlorinated cobalt dicarbollide (CCD) was studied by using m-nitrobenzotrifluoride, phenyltrifluoromethyl sulfone, and 1,2-dichloroethane as diluents. We examined the effects of diluents, of the aqueous phase composition and the nature of substituents in the ATP aryl ring on Am/Eu extraction efficiency and selectivity. The Am/Eu separation factor was found to be close to 100 at the optimal ratio of ATPs: CCD ∝ 1:1. We also studied the extraction of 85 Sr, 137 Cs and 133 Ba; a PhATP-CCD mixture provided the separation of the Sr/Ba pair with a factor of 35. A high resistance of 2,6-bis-aryltetrazolyl pyridines to 6 M nitric and perchloric acids at 95 C was demonstrated. (orig.)

The discovery and the structural basis of an imidazo[4,5-b]pyridine-based p21-activated kinase 4 inhibitor.

Science.gov (United States)

Park, Jeung Kuk; Kim, Sunmin; Han, Yu Jin; Kim, Seong Hwan; Kang, Nam Sook; Lee, Hyuk; Park, SangYoun

2016-06-01

p21-Activated kinases (PAKs) which belong to the family of ste20 serine/threonine protein kinases regulate cytoskeletal reorganization, cell motility, cell proliferation, and oncogenic transformation which are all related to the cellular functions during cancer induction and metastasis. The fact that PAK mutations are detected in multiple tumor tissues makes PAKs a novel therapeutic drug target. In this study, an imidazo[4,5-b]pyridine-based PAK4 inhibitor, KY-04045 (6-Bromo-2-(3-isopropyl-1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-b]pyridine), was discovered using a virtual site-directed fragment-based drug design and was validated using an inhibition assay. Although PAK4 affinity to KY-04045 seems much weaker than that of the reported PAK4 inhibitors, the location of KY-04045 is clearly defined in the structure of PAK4 co-crystallized with KY-04045. The crystal structure illustrates that the pyrazole and imidazopyridine rings of KY-04045 are sufficient for mediating PAK4 hinge loop interaction. Hence, we believe that KY-04045 can be exploited as a basic building block in designing novel imidazo[4,5-b]pyridine-based PAK4 inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polarized proton beams

International Nuclear Information System (INIS)

Roser, T.

1995-01-01

The acceleration of polarized proton beams in circular accelerators is complicated by the presence of numerous depolarizing spin resonances. Careful and tedious minimization of polarization loss at each of these resonances allowed acceleration of polarized proton beams up to 22 GeV. It has been the hope that Siberian Snakes, which are local spin rotators inserted into ring accelerators, would eliminate these resonances and allow acceleration of polarized beams with the same ease and efficiency that is now routine for unpolarized beams. First tests at IUCF with a full Siberian Snake showed that the spin dynamics with a Snake can be understood in detail. The author now has results of the first tests of a partial Siberian Snake at the AGS, accelerating polarized protons to an energy of about 25 GeV. These successful tests of storage and acceleration of polarized proton beams open up new possibilities such as stored polarized beams for internal target experiments and high energy polarized proton colliders

Poly[di-μ2-aqua-μ5-(pyridine-2,6-dicarboxylato-μ3-(pyridine-2,6-dicarboxylato-cobalt(IIdisodium

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Alexander N. Boyko

2011-12-01

Full Text Available In the title compound, [CoNa2(C7H3NO42(H2O2]n, the CoII atom is coordinated by two pyridine N atoms and four carboxylate O atoms from two doubly deprotonated pyridine-2,6-dicarboxylate ligands in a distorted octahedral geometry. One Na+ cation is coordinated by three carboxylate O atoms and two water molecules and the other is coordinated by five carboxylate O atoms and two water molecules in an irregular geometry. The bis(pyridine-2,6-dicarboxylatocobalt complex units are connected by Na+ cations and bridging water molecules into a three-dimensional coordination network. O—H...O hydrogen bonds are formed between the water molecules and the carboxylate O atoms.

Thermodynamics of mixtures containing amines. IX. Application of the concentration-concentration structure factor to the study of binary mixtures containing pyridines

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.es [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos; Garcia de la Fuente, Isaias; Mozo, Ismael [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

2009-10-10

size effects are predominant over steric hindrances to the creation of the OH-N hydrogen bonds, which are expected to increase with the number of methyl groups in the aromatic amine. For a given 1-alkanol ({ne}methanol), S{sub CC}(0) varies in the sequence: pyridine > methyl pyridine {approx} 2,6-dimethylpyridine. For alkyl pyridines, stability seems to be independent of position and number of alkyl groups attached to the aromatic ring of the amine. Mixtures with isomeric 2-alkanols show lower heterocoordination, as the hydroxyl group is more sterically hindered than in 1-alkanols.

Review of the Fermilab main ring accelerator study program as directed to the pp program

International Nuclear Information System (INIS)

Griffin, J.E.; MacLachlan, J.A.; Bridges, J.F.

1981-01-01

Recently the colliding beam goals at Fermilab have been redirected toward 2 TeV c.m. pp physics to be done in the Tevatron. The booster-main ring complex will be the proton injector and the source of protons for anti-proton production. Consequently, the emphasis of recent studies in the main ring has been directed at those problems which arise from the beam manipulation necessary for the pp scenario. These studies are divided into three categories: 1) true storage studies directed toward revealing problems and techniques likely to apply to storage in the Tevatron, 2) beam manipulations necessary for the production of anti-protons, and 3) beam manipulations necessary for producing single proton bunches containing 10/sup 11/ protons each. 16 refs

Polarized proton collider at RHIC

International Nuclear Information System (INIS)

Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N.

2003-01-01

In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to √s=500 GeV

catena-Poly[[(triphenylphosphane-κPcopper(I]-di-μ-bromido-[(triphenylphosphane-κPcopper(I]-μ-1,3-bis(pyridin-4-ylpropane-κ2N:N′

Directory of Open Access Journals (Sweden)

Jinfang Zhang

2012-03-01

Full Text Available Through a diffusion reaction, cuprous bromide, triphenylphosphane and 1,3-bis(pyridin-4-ylpropane (bpp were self-assembled to form the one-dimensional title compound, [Cu2Br2(C13H14N2(C18H15P2]n. Each CuI atom is coordinated by two Br atoms, one P atom from a triphenylphosphane ligand and one N atom from a bpp molecule in a distorted tetrahedral geometry. Two μ2-Br bridges connect two [Cu(PPh3]+ units to form neutral [CuBr(PPh3]2 dimers, which are linked by the flexible bridging bpp ligands to form a one-dimensional chain structure parallel to the c axis. The dihedral angle between the pyridine rings of the bpp ligand is 34.59 (14°.

{N,N′-Bis[1-(pyridin-2-yl)ethyl­idene]­propane-1,3-diamine}­bromidocopper(II) tetra­fluoridoborate

OpenAIRE

Liu, Li-Jun

2011-01-01

In the title compound, [CuBr(C17H20N4)]BF4, the CuII ion is five-coordinated by the four N atoms of the tetradentate Schiff base ligand and by one bromide ion, thereby forming a square-pyramidal CuN4Br coordination geometry. The dihedral angle between the pyridine rings of the Schiff base is 54.39 (18)°. In the crystal, the components are linked by C—H...F interactions.

Vortex-ring-fractal Structure of Atom and Molecule

International Nuclear Information System (INIS)

Osmera, Pavel

2010-01-01

This chapter is an attempt to attain a new and profound model of the nature's structure using a vortex-ring-fractal theory (VRFT). Scientists have been trying to explain some phenomena in Nature that have not been explained so far. The aim of this paper is the vortex-ring-fractal modeling of elements in the Mendeleev's periodic table, which is not in contradiction to the known laws of nature. We would like to find some acceptable structure model of the hydrogen as a vortex-fractal-coil structure of the proton and a vortex-fractal-ring structure of the electron. It is known that planetary model of the hydrogen atom is not right, the classical quantum model is too abstract. Our imagination is that the hydrogen is a levitation system of the proton and the electron. Structures of helium, oxygen, and carbon atoms and a hydrogen molecule are presented too.

Complexation of thorium with pyridine monocarboxylates: A thermodynamic study by experiment and theory

International Nuclear Information System (INIS)

Rama Mohana Rao, D.; Rawat, Neetika; Manna, D.; Sawant, R.M.; Ghanty, T.K.; Tomar, B.S.

2013-01-01

Highlights: ► The thermodynamic parameters have been determined for the first time. ► The Th-picolinate complexation was exothermic in nature. ► The complexation of Th(IV) with the other two isomers was endothermic process. ► Isonicotinate forms stronger complexes than nicotinate with Th(IV). ► The theoretically calculated values are in line with the experimental results. -- Abstract: Complexation of thorium with pyridine monocarboxylates namely picolinic acid (pyridine-2-carboxylic acid), nicotinic acid (pyridine-3-carboxylic acid) and isonicotinic acid (pyridine-4-carboxylic acid) has been studied by potentiometry and calorimetry to determine the thermodynamic parameters (log K, ΔG, ΔH and ΔS) of complexation. All the studies were carried out at 1.0 M ionic strength adjusted by NaClO 4 and at a temperature of 298 K. The detailed analysis of potentiometric data by Hyperquad confirmed the formation of four complexes, ML i (i = 1–4) in case of picolinate but only one complex (ML) in case of nicotinate and isonicotinate. The stepwise formation constant for ML complex (log K ML ) of thorium-picolinate is higher than those of thorium-nicotinate and thorium-isonicotinate complexes. Further the changes in enthalpy during formation of thorium-picolinate complexes are negative whereas the same for the complexes of thorium with the other two isomers was positive. This difference in the complexation process is attributed to chelate formation in case of thorium-picolinate complexes in which the thorium ion is bound to the picolinate through both the nitrogen in the pyridyl ring and one of the carboxylate oxygen atoms. The complexation process of thorium-nicotinate and thorium-isonicotinate are found to be endothermic in nature and are entropy driven confirming the similar binding nature as in simple carboxylate complexes of thorium. The complexation energies, bond lengths and charges on each atom in the complexes of various possible geometries were calculated

Studies of Beam Dynamics in Cooler Rings

International Nuclear Information System (INIS)

Dietrich, J.; Stein, J.; Meshkov, I.; Sidorin, A.; Smirnov, A.

2006-01-01

This report describes the numerical simulation of the crystalline proton beam formation in COSY using BETACOOL code. The study includes the description of experimental results at NAP-M storage ring where the large reduction of the momentum spread was observed for first time. The present simulation shows that this behavior of proton beam can not be explained as ordered state of protons. The numerical simulation of crystalline proton beams was done for COSY parameters. The number of protons when the ordering state can be observed is limited by value 106 particles and momentum spread less then 10-6. Experimental results for the attempt to achieve of ordered state of proton beam for COSY is presented. This work is supported by RFBR grant no. 05-02-16320 and INTAS grant no. 03-54-5584

Propane-1,2-diammonium bis(pyridine-2,6-dicarboxylato-κ3O,N,O′nickelate(II tetrahydrate

Directory of Open Access Journals (Sweden)

Mohammad Ghadermazi

2008-07-01

Full Text Available The reaction of nickel(II nitrate hexahydrate, propane-1,2-diamine and pyridine-2,6-dicarboxylic acid in a 1:2:2 molar ratio in aqueous solution resulted in the formation of the title compound, (C3H12N2[Ni(C7H3NO42]·4H2O or (p-1,2-daH2[Ni(pydc2]·4H2O (where p-1,2-da is propane-1,2-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid. The geometry of the resulting NiN2O4 coordination can be described as distorted octahedral. Considerable C=O...π stacking interactions are observed between the carboxylate C=O groups and the pyridine rings of the (pydc2− fragments, with O...π distances of 3.1563 (12 and 3.2523 (12 Å and C=O...π angles of 95.14 (8 and 94.64 (8°. In the crystal structure, a wide range of non-covalent interactions, consisting of hydrogen bonding [O—H...O, N—H...O and C—H...O, with D...A distances ranging from 2.712 (2 to 3.484 (2 Å], ion pairing, π–π [centroid-to-centroid distance = 3.4825 (8 Å] and C=O...π stacking, connect the various components to form a supramolecular structure.

Thin layer activation (TLA) experiment of piston ring F.J product by using nuclear facility proton beam 12.5 MeV

International Nuclear Information System (INIS)

Sudarmono; Silakhuddin

2002-01-01

The experiment of thin layer activation of piston ring F.J product, was done. The purpose of this experiment are to measure material wearing level by using concentration method. The experiment was carried out by activated piston ring proton beam with energy 12,5 MeV and beam current 1 μA for 30 minutes then was continued by wearing process. The measurement of the wear result activity was carried out by pouring the total of volume of lubricant oil for radioactivity measurement. Measurement of the activity level used the gamma spectroscopy. The minimum wearing duration that can detects a wear was 5 hours. The activity count was 1.230 pulse per 30 seconds which is in accordance with a wear in order of 8 mg of Fe material on 1 liter oil lubricant, this result is same with the result of T. Delvigne namely is less than 10 mgr

Hybrid fluorescent nanoparticles fabricated from pyridine-functionalized polyfluorene-based conjugated polymer as reversible pH probes over a broad range of acidity-alkalinity

International Nuclear Information System (INIS)

Cui, Haijun; Chen, Ying; Li, Lianshan; Tang, Zhiyong; Wu, Yishi; Fu, Hongbing; Tian, Zhiyuan

2014-01-01

Conjugated polymer nanoparticles (CPNs) were developed based on a polyfluorene-based conjugated polymer with thiophene units carrying pyridyl moieties incorporated in the backbone of polymer chains (PFPyT). Hybrid CPNs fabricated from PFPyT and an amphiphilic polymer (NP1) displayed pH-sensitive fluorescence emission features in the range from pH 4.8 to 13, which makes them an attractive nanomaterial for wide range optical sensing of pH values. The fluorescence of hybrid CPNs based on chemically close polyfluorene derivatives without pyridyl moieties (NP3), in contrast, remains virtually unperturbed by pH values in the same range. The fluorescence emission features of NP1 underwent fully reversible changes upon alternating acidification/basification of aqueous dispersions of the CPNs and also displayed excellent repeatability. The observed pH sensing properties of NP1 are attributed to protonation/deprotonation of the nitrogen atoms of the pyridine moieties. This, in turn, leads to the redistribution of electron density of pyridine moieties and their participation in the π-conjugation within the polymer main chains. The optically transparent amphiphilic polymers also exerted significant influence on the pH sensing features of the CPNs, likely by acting as proton sponge and/or acid chaperone. (author)

Histidine in Continuum Electrostatics Protonation State Calculations

Science.gov (United States)

Couch, Vernon; Stuchebruckhov, Alexei

2014-01-01

A modification to the standard continuum electrostatics approach to calculate protein pKas which allows for the decoupling of histidine tautomers within a two state model is presented. Histidine with four intrinsically coupled protonation states cannot be easily incorporated into a two state formalism because the interaction between the two protonatable sites of the imidazole ring is not purely electrostatic. The presented treatment, based on a single approximation of the interrelation between histidine’s charge states, allows for a natural separation of the two protonatable sites associated with the imidazole ring as well as the inclusion of all protonation states within the calculation. PMID:22072521

Dithiafulvene-based organic sensitizers using pyridine as the acceptor for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Cheng, Jun; Cao, Yaxiong; Liang, Xiaozhong; Zheng, Jingxia; Zhang, Fang [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Wei, Shuxian; Lu, Xiaoqing [College of Science, China University of Petroleum, Qingdao, Shandong 266555 (China); Guo, Kunpeng, E-mail: guokunpeng@tyut.edu.cn [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Shihe, E-mail: chsyang@ust.hk [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

2017-05-01

Three dithiafulvene-based metal-free organic sensitizers all using pyridine as the acceptor but with different π-bridges of phenyl (DTF-Py1), thienyl (DTF-Py2) and phenyl-thienyl (DTF-Py3) have been designed, synthesized and used as photosensitizers for dye-sensitized solar cells (DSCs). Introducing thienyl unit into the π-bridge, as well as extension of the π-bridge can dramatically improve their light harvesting ability and suppress the electron recombination, thus uplifting the performance of DSCs. The overall power conversion efficiency of DSC based on DTF-Py3 shows the highest efficiency of 2.61% with a short-circuit photocurrent density of 7.99 mA cm{sup -2}, an open-circuit photovoltage of 630 mV, and a fill factor of 0.52, under standard global AM 1.5 solar light condition. More importantly, the long-term stability of the DTF-Py3 based DSCs under 500 h light-soaking has been demonstrated. - Highlights: • Dithiafulvene sensitizers using pyridine ring as the acceptor were synthesized for the first time. • The power conversion efficiency of 2.61% was obtained for DTF-Py3 sensitized cell. • DTF-Py3 loaded TiO{sub 2} film shows improved light harvesting ability and suppressed electron recombination.

Nonlinear interaction of energetic ring current protons with magnetospheric hydromagnetic waves

International Nuclear Information System (INIS)

Chan, A.A.; Chen, L.; White, R.B.

1989-01-01

In order to study nonlinear wave-particle interactions in the Earth's magnetosphere we have derived Hamiltonian equations for the gyrophase-averaged nonrelativistic motion of charged particles in a perturbed dipole magnetic field. We assume low frequency (less than the proton gyrofrequency) fully electromagnetic perturbations, and we retain finite Larmor radius effects. Analytic and numerical results for the stochastic threshold of energetic protons (approx-gt 100 keV) in compressional geomagnetic pulsations in the Pc 5 range of frequencies 150--600 seconds are presented. These protons undergo a drift-bounce resonance with the Pc 5 waves which breaks the second (longitudinal) and third (flux) adiabatic invariants, while the first invariant (the magnetic moment) and the proton energy are approximately conserved. The proton motion in the observed spectrum of waves is found to be strongly diffusive, due to the overlap of neighboring primary resonances. copyright American Geophysical Union 1989

Nonlinear interaction of energetic ring current protons with magnetospheric hydromagnetic waves

International Nuclear Information System (INIS)

Chan, A.A.; Chen, Liu; White, R.B.

1989-09-01

In order to study nonlinear wave-particle interactions in the earth's magnetosphere we have derived Hamiltonian equations for the gyrophase-averaged nonrealistic motion of charged particles in a perturbed dipole magnetic field. We assume low frequency (less than the proton gyrofrequency) fully electromagnetic perturbations, and we retain finite Larmor radius effects. Analytic and numerical results for the stochastic threshold of energetic protons (approx gt 100 keV) in compressional geomagnetic pulsations in the Pc 5 range of frequencies (150--600 seconds) are presented. These protons undergo a drift-bounce resonance with the Pc 5 waves which breaks the second (longitudinal) and third (flux) adiabatic invariants, while the first invariant (the magnetic moment) and the proton energy are approximately conserved. The proton motion in the observed spectrum of waves is found to be strongly diffusive, due to the overlap of neighboring primary resonances. 17 refs., 2 figs

Effect of alkali metal ions on the pyrrole and pyridine π-electron systems in pyrrole-2-carboxylate and pyridine-2-carboxylate molecules: FT-IR, FT-Raman, NMR and theoretical studies

Science.gov (United States)

Świderski, G.; Wojtulewski, S.; Kalinowska, M.; Świsłocka, R.; Lewandowski, W.

2011-05-01

The FT-IR, FT-Raman and 1H and 13C NMR spectra of pyrrole-2-carboxylic acid (PCA) and lithium, sodium, potassium, rubidium and caesium pyrrole-2-carboxylates were recorded, assigned and compared in the Li → Na → K → Rb → Cs salt series. The effect of alkali metal ions on the electronic system of ligands was discussed. The obtained results were compared with previously reported ones for pyridine-2-carboxylic acid and alkali metal pyridine-2-carboxylates. Calculations for pyrrole-2-carboxylic acid and Li, Na, K pyrrole-2-carboxylates in B3LYP/6-311++G ** level and Møller-Plesset method in MP2/6-311++G ** level were made. Bond lengths, angles and dipole moments as well as aromaticity indices (HOMA, EN, GEO, I 6) for the optimized structures of pyrrole-2-carboxylic acid (PCA) and lithium, sodium, potassium pyrrole-2-carboxylates were also calculated. The degree of perturbation of the aromatic system of ligand under the influence of metals in the Li → Cs series was investigated with the use of statistical methods (linear correlation), calculated aromaticity indices and Mulliken, NBO and ChelpG population analysis method. Additionally, the Bader theory (AIM) was applied to setting the characteristic of the bond critical points what confirmed the influence of alkali metals on the pyrrole ring.

Dihydrogen phosphate-water tape and layers vs dihydrogen phosphate layers tuned by hydrophobic isomeric pyridine-diamine functionalized molecules

Science.gov (United States)

Huang, Jing; Liu, Tong-Peng; Huo, Li-Hua; Deng, Zhao-Peng; Gao, Shan

2017-01-01

Assembly of six isomeric pyridine-diamine-based molecules, N,N‧-bis(pyridin-4-ylmethyl)ethane-1,2-diamine (M1), N,N‧-bis(pyridin-3-ylmethyl)ethane-1,2-diamine (M2), N,N‧-bis(pyridin-2-ylmethyl)ethane-1,2-diamine (M3), N,N‧-bis(pyridin-4-ylmethyl)propane-1,3-diamine (M4), N,N‧-bis(pyridin-3-ylmethyl)propane-1,2-diamine (M5), and N,N‧-bis(pyridin-2-ylmethyl)propane-1,3-diamine (M6), with phosphoric acid (H3PO4) in different ratio (1:2 and 1:4), leads to the formation of nine salts, H2M12+·2H2PO4-·4H2O (1), H2M22+·2H2PO4-·2H2O (2), H2M32+·2H2PO4-·2H2O (3), H4M14+·4H2PO4- (4), H4M24+·4H2PO4- (5), H4M34+·4H2PO4- (6), H2M42+·2H2PO4-·3H2O (7), 2H2M52+·4H2PO4-·2H3PO4 (8), and H2M62+·2H2PO4- (9), which have been characterized by elemental analysis, IR, TG, PL, powder and single-crystal X-ray diffraction. Structural analyses indicate that hydrogen-bonding patterns of H2PO4- anions, conformation of protonated cations can effectively influence the supramolecular architectures through diverse non-covalent interactions. Hydrous salts 1-3 and 7 present 2D and 3D host-guest supramolecular networks, in which the connection of H2PO4- anions and water molecules generates diverse tape and layer motifs. H2PO4- anions in anhydrous salts 4-6 interconnect with each other through hydrogen bonds to form two types of layers, which are joined by discrete H4M4+ cations into 3D inorganic-organic hybrid supramolecular networks. Salts 8-9 also present 2D and 3D host-guest supramolecular networks where the interconnection of H2PO4- anions and its combination with H3PO4 molecules leads to diverse layers. Luminescent analyses indicate that salts 1-9 exhibit violet and blue emission maximum in the range of 390-467 nm at room temperature.

Tris(2,2′-bipyridine-κ2N,N′cobalt(III bis[bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6cobaltate(III] perchlorate dimethylformamide hemisolvate 1.3-hydrate

Directory of Open Access Journals (Sweden)

Irina A. Golenya

2012-10-01

Full Text Available In the title compound, [Co(C10H8N23][Co(C7H3NO42]2(ClO4·0.5C3H7NO·1.3H2O, the CoIII atom in the complex cation is pseudooctahedrally coordinated by six N atoms of three chelating bipyridine ligands. The CoIII atom in the complex anion is coordinated by two pyridine N atoms and four carboxylate O atoms of two doubly deprotonated pyridine-2,6-dicarboxylate ligands in a distorted octahedral geometry. One dimethylformamide solvent molecule and two water molecules are half-occupied and one water molecule is 0.3-occupied. O—H...O hydrogen bonds link the water molecules, the perchlorate anions and the complex anions. π–π interactions between the pyridine rings of the complex anions are also observed [centroid–centroid distance = 3.804 (3 Å].

Synthesis of pyridines over zeolites in gas phase

Czech Academy of Sciences Publication Activity Database

Slobodník, M.; Hronec, M.; Cvengrošová, Z.; Voláková, Martina; Čejka, Jiří

2007-01-01

Roč. 72, 5-6 (2007), s. 618-628 ISSN 0010-0765 Grant - others:VEGA(XE) 1/2459/05 Institutional research plan: CEZ:AV0Z40400503 Source of funding: R - rámcový projekt EK Keywords : pyridine * pyridine bases * ZSM-5 * ethanol Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.879, year: 2007

Proton and hydrogen formation by cyclohexyl benzene during overcharge of Li-ion batteries

Science.gov (United States)

Lee, Hochun; Kim, Soojin; Jeon, Jongho; Cho, Jeong-Ju

This study provides experimental evidence for proton and hydrogen formation caused by the anodic electropolymerization of cyclohexyl benzene (CHB), which is a popular electrolyte additive for overcharge protection of lithium-ion batteries (LIBs). It is found that considerable H 2 evolution is observed in overcharged LiCoO 2/graphite cells, especially when CHB is included as an electrolyte additive. In order to confirm the proton generation during the CHB oxidation, Pt/Pt-rotating ring disc electrode (RRDE) measurements are performed in 1 M Li(C 2F 5SO 2) 2N ethylene carbonate/ethyl methyl carbonate (1/2, v/v) solutions with and without CHB. The cathodic ring current is intimately correlated to the anodic disc current, and the cathodic reaction at the ring is determined to be the reduction of the proton. The proton generation efficiency during the CHB oxidation is as high as 90%. Proton liberation is also observed during the anodic decomposition of the electrolyte solvents, although it occurs in a much less stoichiometric way compared with that during the CHB oxidation.

Studies Performed in Preparation for the Spallation Neutron Source Accumulator Ring Commissioning

CERN Document Server

Cousineau, Sarah M; Henderson, Stuart; Holmes, Jeffrey Alan; Plum, Michael

2005-01-01

The Spallation Neutron Source accumulator ring will compress 1.5?1014, 1 GeV protons from a 1 ms bunch train to a single 695 ns proton bunch for use in neutron spallation. Due to the high beam power, unprecedented control of beam loss will be required in order to control radiation and allow for hands-on maintenance in most areas of the ring. A number of detailed investigations have been performed to understand the primary sources of beam loss and to predict and mitigate problems associated with radiation hot spots in the ring. The ORBIT particle tracking code is used to perform realistic simulations of the beam accumulation in the ring, including detailed modeling of the injection system, transport through the measured magnet fields including higher order multipoles, and beam loss and collimation. In this paper we present the results of a number of studies performed in preparation for the 2006 commissioning of the accumulator ring.

A Study of Storage Ring Requirements for an Explosive Detection System Using NRA Method.

Energy Technology Data Exchange (ETDEWEB)

Wang, T. F. (Tai-Sen F.); Kwan, T. J. T. (Thomas J. T.)

2005-01-01

The technical feasibility of an explosives detection system based on the nuclear resonance absorption (NRA) of gamma rays in nitrogen-rich materials was demonstrated at Los Alamos National Laboratory (LANL) in 1993 by using an RFQ proton accelerator and a tomographic imaging prototype. The study is being continued recently to examine deployment of such an active interrogation system in realistic scenarios. The approach is to use an accelerator and electron-cooling-equipped storage rings(s) to provide the high quality and high current proton beam needed in a practical application. In this work, we investigate the requirements on the storage ring(s) with external gamma-ray-production target for a variant of the airport luggage inspection system considered in the earlier LANL experiments. Estimations are carried out based on the required inspection throughput, the gamma ray yield, the proton beam emittance growth due to scatters with the photon-production target, beam current limit in the storage ring, and the electron-cooling rate. Studies using scaling and reasonable parameter values indicate that it is possible to use no more than a few storage rings per inspection station in a practical NRA luggage inspection complex having more than ten inspection stations.

Some topics in beam dynamics of storage rings

International Nuclear Information System (INIS)

Mais, H.

1996-06-01

In the following report we want to review some beam dynamics problems in accelerator physics. Theoretical tools and methods are introduced and discussed, and it is shown how these concepts can be applied to the study of various problems in storage rings. The first part treats Hamiltonian systems (proton accelerators) whereas the second part is concerned with explicitly stochastic systems (e.g. electron storage rings). (orig.)

3-(Aminocarbonylpyridinium diaqua-bis(pyridine-2,6-dicarboxylatobismuthate(III monohydrate

Directory of Open Access Journals (Sweden)

Janet Soleimannejad

2012-07-01

Full Text Available The asymmetric unit of the ionic title compound, (C6H7N2O[Bi(C7H3NO42(H2O2]·H2O or (acpyH[Bi(pydc2(H2O2]·H2O, contains an [Bi(pydc2(H2O2]− anion (where pydcH2 is pyridine-2,6-dicarboxylic acid, a protonated 3-(aminocarbonylpyridine as counter-ion, (acpyH+, and one uncoordinated water molecule. The anion is an eight-coordinate complex with a square-antiprismatic geometry around the BiIII atom. In the crystal, extensive O—H...O and N—H...O hydrogen bonds, as well as ion pairing, C=O...π interactions [O...centroid distance = 3.583 (5 Å], π–π stacking [centroid–centroid distance = 3.864 (3 Å], and C—H...π and C—H...O interactions, play an important role in the formation and stabilization of the three-dimensional supramolecular structure.

Nuclear magnetic resonance and relaxation studies of the structure and segmental motions of 4-vinyl-pyridinic polymers in solution

International Nuclear Information System (INIS)

Ghesquiere, Denis

1978-01-01

The poly 4-vinylpyridine, its quaternized products from HBr and n-alkyl-bromides, and its N-oxide form have been investigated by nuclear magnetic resonance of proton at 100 and 250 MHz and carbon-13 at 25.15 MHz, The 1 H and 13 C relaxation data of poly-vinylpyridine and its ionized form have been correlated with conformational calculations. They have been interpreted in terms of an isotropic motion of the macromolecular segments introducing a correlation times distribution and of an oscillation motion of the pyridyl groups. The same treatment have been used for the 13 C relaxation data of the poly 4- vinyl-pyridines quaternized at various rates by n-alkyl-bromides. The 13 C relaxation times in the side-chains have been interpreted first by semi-empirical equations assuming an exponential gradient of the diffusion coefficients along them, and also by a Monte Carlo simulation of the motions. The results have shown that the quaternization induces a strong rigidity of the macromolecular backbone and that the dominant effect is the electrostatic interactions. On the other hand it seems that the motion of pyridyl rings is not affected. Moreover we have found a range of oscillation amplitudes in agreement with conformational energy calculations and the results obtained from a conformational study of the poly 4-vinylpyridine N-oxide by 1 H and 13 C NMR contact shifts induced by Ni II paramagnetic ions. (author) [fr

The PEP [positron-electron-proton] electron-positron ring: An update

International Nuclear Information System (INIS)

1975-03-01

The first stage of the positron-electron-protron (PEP) colliding-beam system, which has been under joint study by a Lawrence Berkeley Laboratory--Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e + e/sup /minus// ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus around the interaction regions was set provisionally at 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup /minus/2/s/sup /minus/1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described. 7 figs., 3 tabs

Rates and energetics of tyrosine ring flips in yeast iso-2-cytochrome c

International Nuclear Information System (INIS)

Nall, B.T.; Zuniga, E.H.

1990-01-01

Isotope-edited nuclear magnetic resonance spectroscopy is used to monitor ring flip motion of the five tyrosine side chains in the oxidized and reduced forms of yeast iso-2-cytochrome c. With specifically labeled protein purified from yeast grown on media containing [3,5- 13 C]tyrosine, isotope-edited one-dimensional proton spectra have been collected over a 5-55 degree C temperature range. The spectra allow selective observation of the 10 3,5 tyrosine ring proton resonances and, using a two-site exchange model, allow estimation of the temperature dependence of ring flip rates from motion-induced changes in proton line shapes. For the reduced protein, tyrosines II and IV are in fast exchange throughout the temperature range investigated, or lack resolvable differences in static chemical shifts for the 3,5 ring protons. Tyrosines I, III, and V are in sloe exchange at low temperatures and in fast exchange at high temperatures. Spectral simulations give flip rates for individual tyrosines in a range of one flip per second at low temperatures to thousands of flips per second at high temperatures. Eyring plots show that two of the tyrosines (I and III) have essentially the same activation parameters. Tentative sequence-specific assignments for the tyrosines in reduced iso-2 are suggested by comparison to horse cytochrome c. For oxidized iso-2, five resonances are observed at high temperatures, suggesting flip rates for all five tyrosines sufficient to average static chemical shift differences. At lower temperatures, there is evidence of intermediate and slow flipping for some of the rings

Sulfonated 1,3-bis(4-pyridylpropane

Directory of Open Access Journals (Sweden)

Ore Kuyinu

2011-06-01

Full Text Available In the title compound, 4-[3-(3-sulfonatopyridin-1-ium-4-ylpropyl]pyridin-1-ium-3-sulfonate, C13H14N2O6S2, the molecule is zwitterionic, with the sulfonic acid proton transfered to the basic pyridine N atom. Also, the structure adopts a butterfly-like conformation with the sulfonate groups on opposite sides of the `wings'. The dihedral angle between the two pyridinium rings is 83.56 (7°, and this results in the molecule having a chiral conformation and packing. There is strong intermolecular hydrogen bonding between the pyridinium H and sulfonate O atoms of adjoining molecules. In addition, there are weaker intermolecular C—H...O interactions.

Crystal structure and Hirshfeld surface analysis of hexakis(μ-benzoato-κ2O:O′bis(pyridine-3-carbonitrile-κN1trizinc(II

Directory of Open Access Journals (Sweden)

Tuncer Hökelek

2017-12-01

Full Text Available The asymmetric unit of the title complex, [Zn3(C7H5O26(C6H4N22], contains one half of the complex molecule, i.e. one and a half ZnII cations, three benzoate (Bnz and one pyridine-3-carbonitrile (Cpy molecule; the Bnz anions act as bidentate ligands through the carboxylate O atoms, while the Cpy ligand acts as a monodentate N(pyridine-bonding ligand. The complete centrosymmetric trinuclear complex thus comprises a linear array of three ZnII cations. The central ZnII cation shows an octahedral coordination and is bridged to each of the terminal ZnII cations by three Bnz anions. By additional coordination of the CPy ligand, the terminal ZnII cations adopt a trigonal–pyramidal coordination environment. In the crystal, the Bnz anions link to the Cpy N atoms via weak C—H...N hydrogen bonds, forming a two-dimensional network. C—H...π and π–π interactions [between the benzene and pyridine rings of adjacent molecules with an intercentroid distance of 3.850 (4 Å] help to consolidate a three-dimensional architecture. The Hirshfeld surface analysis confirms the role of H-atom contacts in establishing the packing.

The evolution of ring current ion energy density and energy content during geomagnetic storms based on Van Allen Probes measurements

International Nuclear Information System (INIS)

Zhao, H.; University of Colorado, Boulder, CO; Li, X.; University of Colorado, Boulder, CO; Baker, D. N.

2015-01-01

Enabled by the comprehensive measurements from the Magnetic Electron Ion Spectrometer (MagEIS), Helium Oxygen Proton Electron mass spectrometer (HOPE), and Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instruments onboard Van Allen Probes in the heart of the radiation belt, the relative contributions of ions with different energies and species to the ring current energy density and their dependence on the phases of geomagnetic storms are quantified. The results show that lower energy (<50 keV) protons enhance much more often and also decay much faster than higher-energy protons. During the storm main phase, ions with energies <50 keV contribute more significantly to the ring current than those with higher energies; while the higher-energy protons dominate during the recovery phase and quiet times. The enhancements of higher-energy proton fluxes as well as energy content generally occur later than those of lower energy protons, which could be due to the inward radial diffusion. For the 29 March 2013 storm we investigated in detail that the contribution from O + is ~25% of the ring current energy content during the main phase and the majority of that comes from <50 keV O + . This indicates that even during moderate geomagnetic storms the ionosphere is still an important contributor to the ring current ions. Using the Dessler-Parker-Sckopke relation, the contributions of ring current particles to the magnetic field depression during this geomagnetic storm are also calculated. In conclusion, the results show that the measured ring current ions contribute about half of the Dst depression.

Lithium salt of N,N-dimethylsalicylamide in pyridine and pyridine-water solutions. NMR study on the internal rotation about the C-N bond

Energy Technology Data Exchange (ETDEWEB)

Gryff-Keller, A; Szczecinski, P [Politechnika Warszawska (Poland)

1981-01-01

NMR spectra of the title compound in pyridine and pyridine-water mixtures have been measured at various temperatures. The dependence of internal rotation rate and of chemical shift difference between N-CH/sub 3/ signals on the solvent composition has been discussed with reference to structure of the solution investigated.

Electron beam depolarization in a damping ring

International Nuclear Information System (INIS)

Minty, M.

1993-04-01

Depolarization of a polarized electron beam injected into a damping ring is analyzed by extending calculations conventionally applied to proton synchrotrons. Synchrotron radiation in an electron ring gives rise to both polarizing and depolarizing effects. In a damping ring, the beam is stored for a time much less than the time for self polarization. Spin flip radiation may therefore be neglected. Synchrotron radiation without spin flips, however, must be considered as the resonance strength depends on the vertical betatron oscillation amplitude which changes as the electron beam is radiation damped. An expression for the beam polarization at extraction is derived which takes into account radiation damping. The results are applied to the electron ring at the Stanford Linear Collider and are compared with numerical matrix formalisms

Kinetic study of the substitution of pyridine by cyanide in the bis(pyridine)cobalt(III)hematoporphyrin-IX: distinguishing between Isub(d) and D mechanism

International Nuclear Information System (INIS)

Birush, M.; Pribanicj, M.

1977-01-01

''Mass-law (rate) retardation'' effect shows that the reaction between the cyanide ion and bis(pyridine)cobalt(III)hematoporphyrin-IX complex to give (CN) 2 cobalt(III)hematoporphyrin-IX occurs by a purely dissociative (D but not Isub(d)) mechanism in chloroform. Limiting rate constant at the excess of cyanide ion concentration at 25 deg C was found to be 2.5x10 -3 S -1 and the competition ratio of pyridine (ksub(-) 1 ) and the cyanide ion (k 2 ) for a five coordinate intermediate (pyridin) cobalt(III)hematoporphyrin-IX complex was obtained as ksub(-) 1 /k 2 =0.35. (author)

Proton induction linacs as high-intensity neutron sources

International Nuclear Information System (INIS)

Keefe, D.; Hoyer, E.

1981-01-01

Proton induction linacs are explored as high intensity neutron sources. The induction linac - concept, properties, experience with electrons, and possibilities - and its limitations for accelerating ions are reviewed. A number of proton induction linac designs are examined with the LIACEP program and general conclusions are given. Results suggest that a proton induction accelerator of the lowest voltage, consistent with good neutron flux, is preferred and could well be cost competitive with the usual rf linac/storage ring designs. (orig.)

Molecular and crystal structures of the products of crystallization of (N'-furfurylidene)isonicotinoylhydrazide from aqueous solutions of hydrochloric and acetic acids

International Nuclear Information System (INIS)

Chuev, I.I.; Nikonova, L.A.; Atovmyan, E.G.; Utenyshev, A.N.; Aldoshin, S.M.

2001-01-01

Crystals of (N ' -furfurylidene)isonicotinoylhydrazide (I), which have been isolated from a water-methanol solution of hydrochloric acid (Ia) and an aqueous solution (∼50%) of acetic acid (Ib), are studied by X-ray diffraction. In Ia, the nitrogen atom of the pyridine ring is protonated. In the crystal, the intermolecular C=O···HN(Py) hydrogen bonds link the I · H + cations into chains which are bound through centrosymmetric NH···W···Cl - ···W ' ···H ' N ' bridges. In molecule Ib, no protonation occurs; however, its pyridine N atom is blocked by the hydroxyl H atom of a solvate molecule of acetic acid. Crystals Ib have a layered structure. The crystallization water molecule is involved in the formation of three intermolecular hydrogen bonds, namely, those with the H atom of the amide group and the carbonyl O atoms of molecule I and an acetic acid molecule of the neighboring layer

Triazole-pyridine ligands: a novel approach to chromophoric iridium arrays

NARCIS (Netherlands)

Juríček, M.; Felici, M.; Contreras-Carballada, P.; Lauko, J.; Bou, S.R.; Kouwer, P.H.J.; Brouwer, A.M.; Rowan, A.E.

2011-01-01

We describe a novel modular approach to a series of luminescent iridium complexes bearing triazole-pyridine-derived ligands that were conveniently prepared by using "click" chemistry. One, two or three triazole-pyridine units were effectively built into the heteroaromatic macromolecule using

A new and general method for the preparation of novel II-heterocyclic derivatives of ruthenium [C5Me5Ru (η6-arene)]X (arene = benzene, thiophene, 3-methylthiophene, benzothiophene, pyridine, 2.6 and 3.5-lutidine, quinoline, acridine). X-ray crystal structure of [(C5Me5)2Ru2Cl2(pyridine)2] PF6

International Nuclear Information System (INIS)

Chaudret, B.; Jalon, F.; Perez-Manrique, M.; Lahoz, F.; Plou, F.J.

1990-01-01

Zinc reduction of (Cp*RuCl 2 ) n (Cp* = C 5 Me 5 ) in acetone or THF followed by addition of 1 equivalent of an arene or aromatic heterocycle leads to compounds of general formulation [Cp* Ru(arene)]X (X = Cl, BF 4 ). Coordination of benzene is rapid and competes successfully with any other arene. Thiophene and 3-methylthiophene give stable π adducts whereas benzothiophene is coordinated through the benzene not through the heterocyclic ring. 2.6 and 3.5-lutidine coordinate through the ring, thus demonstrating an electronic rather than steric stabilization. Again, quinoline and acridine coordinate through the benzene ring. Pyridine gives an unstable π adduct in THF. A paramagnetic mixed-valence species, byproduct of the reaction in THF, has been characterized by an X-ray crystal structure determination. Crystals are triclinic, space group P-1

N-O chemistry for antibiotics: discovery of N-alkyl-N-(pyridin-2-yl)hydroxylamine scaffolds as selective antibacterial agents using nitroso Diels-Alder and ene chemistry.

Science.gov (United States)

Wencewicz, Timothy A; Yang, Baiyuan; Rudloff, James R; Oliver, Allen G; Miller, Marvin J

2011-10-13

The discovery, syntheses, and structure-activity relationships (SAR) of a new family of heterocyclic antibacterial compounds based on N-alkyl-N-(pyridin-2-yl)hydroxylamine scaffolds are described. A structurally diverse library of ∼100 heterocyclic molecules generated from Lewis acid-mediated nucleophilic ring-opening reactions with nitroso Diels-Alder cycloadducts and nitroso ene reactions with substituted alkenes was evaluated in whole cell antibacterial assays. Compounds containing the N-alkyl-N-(pyridin-2-yl)hydroxylamine structure demonstrated selective and potent antibacterial activity against the Gram-positive bacterium Micrococcus luteus ATCC 10240 (MIC(90) = 2.0 μM or 0.41 μg/mL) and moderate activity against other Gram-positive strains including antibiotic resistant strains of Staphylococcus aureus (MRSA) and Enterococcus faecalis (VRE). A new synthetic route to the active core was developed using palladium-catalyzed Buchwald-Hartwig amination reactions of N-alkyl-O-(4-methoxybenzyl)hydroxylamines with 2-halo-pyridines that facilitated SAR studies and revealed the simplest active structural fragment. This work shows the value of using a combination of diversity-oriented synthesis (DOS) and parallel synthesis for identifying new antibacterial scaffolds.

The methylcobalt(III) complex of a tetrapodal pentadentate amine ligand, 2,6-bis(1′,3′-diamino-2′-methyl-prop-2′-yl)pyridine

DEFF Research Database (Denmark)

Grohmann, Andreas; Heinemann, Frank W; Kofod, Pauli

1999-01-01

The pentaamine methylcobalt(III) compound [Co(pyN4)(CH3)](NO3)2 (pyN4=2,6-bis(1′,3′-diamino-2′-methyl-prop-2′-yl)pyridine) has been synthesised from [Co(NH3)5(CH3)](NO3)2 and pyN4 by ligand exchange, and characterised by IR, 1H, 13C and 59Co NMR spectroscopy as well as elemental analysis. The str......The pentaamine methylcobalt(III) compound [Co(pyN4)(CH3)](NO3)2 (pyN4=2,6-bis(1′,3′-diamino-2′-methyl-prop-2′-yl)pyridine) has been synthesised from [Co(NH3)5(CH3)](NO3)2 and pyN4 by ligand exchange, and characterised by IR, 1H, 13C and 59Co NMR spectroscopy as well as elemental analysis...... nitrogen atom, while the four equivalent primary amino groups take the equatorial positions. The other axial position, trans to the pyridine ring, is occupied by the methyl group. The Co–Npy bond length of 2.018(2) Å is significantly elongated compared with other cobalt(III) complexes of the pyN4 ligand...

ISABELLE: a proposal for construction of a proton--proton storage accelerator facility

International Nuclear Information System (INIS)

1976-05-01

The construction of an Intersecting Storage Accelerator Facility (ISA or ISABELLE) at Brookhaven National Laboratory is proposed. ISABELLE will permit the exploration of proton-proton collisions at center-of-mass energies continuously variable from 60 to 400 GeV and with luminosities of 10 32 to 10 33 cm -2 sec -1 over the entire range. An overview of the physics potential of this machine is given, covering the production of charged and neutral intermediate vector bosons, the hadron production at high transverse momentum, searches for new, massive particles, and the energy dependence of the strong interactions. The facility consists of two interlaced rings of superconducting magnets in a common tunnel about 3 km in circumference. The proton beams will collide at eight intersection regions where particle detectors will be arranged for studying the collision processes. Protons of approximately 30 GeV from the AGS will be accumulated to obtain the design current of 10A prior to acceleration to final energy. The design and performance of existing full-size superconducting dipoles and quadrupoles is described. The conceptual design of the accelerator systems and the conventional structures and buildings is presented. A preliminary cost estimate and construction schedule are given. Possible future options such as proton-antiproton, proton-deuteron and electron-proton collisions are discussed

Synthesis and characterization of two novel pyridine-containing framework gallium ethylenediphosphonates

International Nuclear Information System (INIS)

Yuan Zhanhui; Clegg, William; Attfield, Martin P.

2006-01-01

Two novel gallium diphosphonates, (C 5 H 5 N)Ga 3 F(O 3 PC 2 H 4 PO 3 ) 2 (I) (triclinic, P-1, a=8.2880(12) A, b=11.7197(16) A, c=11.7601(17) A, α=71.589(3) o , β=70.577(3) o , γ=77.313(3) o , V=1013.7(2) A 3 , Z=2, R 1 =0.0352, wR 2 =0.0980) and (C 5 H 5 NH) 2 [Ga 4 F 2 (O 3 PC 2 H 4 PO 3 ) 3 ] (II) (triclinic, P-1, a=8.670(4) A, b=9.742(3) A, c=10.406(2) A, α=81.44(3) o , β=65.83(5) o , γ=67.16(3) o , V=739.0(4) A 3 , Z=2, R 1 =0.0600, wR 2 =0.1495) have been synthesised by solvothermal methods in the presence of pyridine and their structures determined using single-crystal X-ray diffraction data. Both compounds I and II are composed of various Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules that are directly bound to some of the Ga atoms in I, and are protonated as pyridinium cations in II. Compounds I has a charge-neutral framework, while compound II has an anionic framework. Both materials provide rare examples of organically structure-directed framework metal diphosphonate materials. - Graphical abstract: (C 5 H 5 N)Ga 3 F(O 3 PC 2 H 4 PO 3 ) 2 (I) and (C 5 H 5 NH) 2 [Ga 4 F 2 (O 3 PC 2 H 4 PO 3 ) 3 ] (II) are novel gallium diphosphonate materials composed of Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules or pyridinium cations and are examples of organically structure-directed framework metal diphosphonates

Pre-treatment of pyridine wastewater by new cathodic-anodic-electrolysis packing.

Science.gov (United States)

Jin, Yang; Yue, Qinyan; Yang, Kunlun; Wu, Suqing; Li, Shengjie; Gao, Baoyu; Gao, Yuan

2018-01-01

A novel cathodic-anodic-electrolysis packing (CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4'-diamino-2,2'-disulfonic acid (DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of pH, hydraulic retention time (HRT), the air-liquid ratio (A/L) and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon (TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921kg/m 3 , 1086kg/m 3 , 25% and 29.89m 2 /g, respectively; the removal of TOC and pyridine could reach 50% and 58% at the optimal experimental conditions (pH=3, HRT=8hr, A/L=2). Notably, the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. Copyright © 2017. Published by Elsevier B.V.

Resonance Raman detection of iron-ligand vibrations in cyano(pyridine)(octaethylporphinato)iron(III): Effects of pyridine basicity on the Fe-CN bond strength

International Nuclear Information System (INIS)

Uno, Tadayuki; Hatano, Keiichiro; Nishimura, Yoshifumi; Arata, Yoji

1988-01-01

The influence of axial ligand basicity on the bonding of iron(III) in cyano adducts of octaethylporphyrin has been studied by resonance Raman spectroscopy. In a six-coordinate ferric low-spin complex, cyano(pyridine)(octaethylporphinato)iron(III), Fe(OEP)(CN)(py), Raman lines at 449 and 191 cm -1 were assigned to the ν(Fe-CN) and ν(Fe-py) stretching modes, respectively. When pyridine was displaced with its derivatives, py-X, where X = 4-cyano, 3-acetyl, 3-methyl, 4-methyl, 3,4-dimethyl, and 4-dimethylamino, the ν(Fe-CN) stretching frequency was found to decrease in the complex with a high pyridine basicity. It was concluded that the stronger the trans pyridine basicity, the weaker the iron-carbon (cyanide) bond. A clear frequency shift was observed in the ν 4 model, though most of the porphyrin vibrations were insensitive to the ligand substitution. The frequency of the ν 4 mode, which is the C a -N(pyrrole) breathing vibration of the porphyrin skeleton, was found to increase with an increase in pyridine basicity. This is contrary to what was found in ferrous low-spin hemes as CO complexes. The ν 4 shift in the CN complexes was explained in terms of forward π donation; donation of electrons from the porphyrin π orbital to the d π vacancy of the low-spin iron(III) weakened the C a -N(pyrrole) bonds and hence decreased the ν 4 frequency. 32 references, 8 figures

Development of high intensity proton accelerator

International Nuclear Information System (INIS)

Mizumoto, M.; Kusano, J.; Hasegawa, K.; Ouchi, N.; Oguri, H.; Kinsho, M.; Touchi, Y.; Honda, Y.; Mukugi, K.; Ino, H.; Noda, F.; Akaoka, N.; Kaneko, H.; Chishiro, E.; Fechner, B.

1997-01-01

The high-intensity proton linear accelerator with an energy of 1.5 GeV and an average current of 5.33mA has been proposed for the Neutron Science Project (NSP) at JAERI. the NSP is aiming at exploring nuclear technologies for nuclear waste transmutation based on a proton induced spallation neutrons. The proposed accelerators facilities will be also used in the various basic research fields such as condensed matter physics in combination with a high intensity proton storage ring. The R and D work has been carried out for the components of the front-end of the proton accelerator. For the high energy portion above 100 MeV, superconducting (SC) accelerator linac has been designed and developed as a major option. (Author) 7 refs

The proton transfer reaction in malonaldehyde derivatives: Substituent effects and quasi-aromaticity of the proton bridge

International Nuclear Information System (INIS)

Palusiak, Marcin; Simon, Silvia; Sola, Miquel

2007-01-01

The proton transfer in malonaldehyde and in some of its derivatives have been considered in order to study the interrelation between the reaction barrier and the π-delocalization in the quasi-ring. A set of simple and mostly common substituents having different properties in resonance effect according to values of substituents constants were chosen in order to simulate the influence of substitution in position 2 or in position 1 (or 3) of malonaldehyde on the quasi-aromaticity and H-bonding. The following substituents have been taken into consideration: NO, NO 2 , CN, CHO, F, H, CH 3 , OCH 3 , OH, and NH 2 . Our results show that when the substituent is attached at position 2 of the quasi-ring, the resonance effect predominates over the field/inductive effect which leads to changes in H-bonding and quasi-aromaticity of the ring motif, while in the case of 1(3) substitution the field/inductive effect is significantly more effective influencing the HB strength, and thus, the proton transfer barrier. Somehow counterintuitively, for the 1(3) substituted systems, the most stable isomer is the one having the weakest HB and lower aromaticity. The reason for this surprising behaviour is discussed

Independent component analysis applied to long bunch beams in the Los Alamos Proton Storage Ring

Science.gov (United States)

Kolski, Jeffrey S.; Macek, Robert J.; McCrady, Rodney C.; Pang, Xiaoying

2012-11-01

Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis, ICA is more robust to noise, coupling, and nonlinearity. The conventional ICA application to turn-by-turn position data from multiple beam position monitors (BPMs) yields information about cross-BPM correlations. With this scheme, multi-BPM ICA has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch revealing correlations of particle motion within the beam bunch. We digitize beam signals of the long bunch at the Los Alamos Proton Storage Ring with a single device (BPM or fast current monitor) for an entire injection-extraction cycle. ICA of the digitized beam signals results in source signals, which we identify to describe varying betatron motion along the bunch, locations of transverse resonances along the bunch, measurement noise, characteristic frequencies of the digitizing oscilloscopes, and longitudinal beam structure.

Independent component analysis applied to long bunch beams in the Los Alamos Proton Storage Ring

Directory of Open Access Journals (Sweden)

Jeffrey S. Kolski

2012-11-01

Full Text Available Independent component analysis (ICA is a powerful blind source separation (BSS method. Compared to the typical BSS method, principal component analysis, ICA is more robust to noise, coupling, and nonlinearity. The conventional ICA application to turn-by-turn position data from multiple beam position monitors (BPMs yields information about cross-BPM correlations. With this scheme, multi-BPM ICA has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch revealing correlations of particle motion within the beam bunch. We digitize beam signals of the long bunch at the Los Alamos Proton Storage Ring with a single device (BPM or fast current monitor for an entire injection-extraction cycle. ICA of the digitized beam signals results in source signals, which we identify to describe varying betatron motion along the bunch, locations of transverse resonances along the bunch, measurement noise, characteristic frequencies of the digitizing oscilloscopes, and longitudinal beam structure.

Bis{2-[(pyridin-2-ylmethylideneamino]benzoato-κ3N,N′,O}chromium(III nitrate monohydrate

Directory of Open Access Journals (Sweden)

Elena A. Buvaylo

2014-04-01

Full Text Available The title complex salt hydrate, [Cr(C13H9N2O22]NO3·H2O, comprises discrete cations, nitrate anions and solvent water molecules. The CrIII atom is octahedrally coordinated by two anionic Schiff base ligands with the O atoms being cis. The two ligands differ significantly with dihedral angles between the pyridine and benzene rings of 4.8 (2 and 24.9 (2°. The nitrate anion and solvent water molecule were modelled as being disordered, with the major components having site-occupancy values of 0.856 (14 and 0.727 (16, respectively. The crystal is built of alternating layers of cations and of anions plus water molecules, stacked along the c axis.

A NEW RELATIVE PROTON POLARIMETER FOR RHIC

International Nuclear Information System (INIS)

HUANG, H.; ALEKSEEV, I.; BUNCE, G.; BRUNER, N.; DESHPANDE, A.; GOTO, Y.; FIELDS, D.; IMAI, K.

2001-01-01

An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region has been installed and commissioned in the Blue ring of RHIC during the first RHIC polarized proton commissioning in September, 2000. The polarimeter consists of ultra-thin carbon targets and four silicon detectors. All elements are in a 1.6 meter vacuum chamber. This paper summarizes the polarimeter design issues and recent commissioning results

Functional conjugated pyridines via main-group element tuning.

Science.gov (United States)

Stolar, Monika; Baumgartner, Thomas

2018-03-29

Pyridine-based materials have seen widespread attention for the development of n-type organic materials. In recent years, the incorporation of main-group elements has also explored significant advantages for the development and tunability of organic conjugated materials. The unique chemical and electronic structure of main-group elements has led to several enhancements in conventional organic materials. This Feature article highlights recent main-group based pyridine materials by discussing property enhancements and application in organic electronics.

Proton storage ring (PSR) diagnostics and control system

International Nuclear Information System (INIS)

Clout, P.

1983-01-01

When any new accelerator or storage ring is built that advances the state of the art, the diagnostic system becomes extremely important in tuning the facility to full specification. This paper will discuss the various diagnostic devices planned or under construction for the PSR and their connection into the control system

A Study of Storage Ring Requirements for an Explosive Detection System Using NRA Method

CERN Document Server

Wang, Tai-Sen

2005-01-01

The technical feasibility of an explosives detection system based on the nuclear resonance absorption (NRA) of gamma rays in nitrogen-rich materials was demonstrated at Los Alamos National Laboratory (LANL) in 1993 by using an RFQ proton accelerator and a tomographic imaging prototype.* The study is being continued recently to examine deployment of such an active interrogation system in realistic scenarios. The approach is to use a cyclotron and electron-cooling-equipped storage rings(s) to provide the high quality and high current proton beam needed in a practical application. In this work, we investigate the storage ring requirements for a variant of the airport luggage inspection system considered in the earlier LANL experiments. Estimations are carried out based on the required inspection throughput, the gamma ray yield, the proton beam emittance growth due to scattering with the photon-production target, beam current limit in the storage ring, and the electron cooling rate. Studies using scaling and reas...

Measurement of pion, kaon and proton production in proton-proton collisions at $\\sqrt{s}$ = 7 TeV

CERN Document Server

Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erhardt, Filip; Eschweiler, Dominic; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Eum, Jongsik; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hippolyte, Boris; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kadyshevskiy, Vladimir; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Kamal; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kouzinopoulos, Charalampos; Kovalenko, Oleksandr; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Graham Richard; Lee, Seongjoo; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leoncino, Marco; Levai, Peter; Li, Shuang; Li, Xiaomei; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Loizides, Constantinos; Lokesh, Kumar; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martin, Nicole Alice; Martin Blanco, Javier; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Masui, Hiroshi; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Minervini, Lazzaro Manlio; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Nattrass, Christine; Nayak, Kishora; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Paola; Paic, Guy; Pajares Vales, Carlos; Pal, Susanta Kumar; Pan, Jinjin; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Seeder, Karin Soraya; Seger, Janet Elizabeth; Sekiguchi, Yuko; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Symons, Timothy; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tanaka, Naoto; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasnopolskiy, Stanislav; Yin, Zhongbao; Yokohama, Hiroki; Yoo, In-Kwon; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

2015-05-27

The measurement of primary $\\pi^{\\pm}$, K$^{\\pm}$, p and $\\overline{p}$ production at mid-rapidity ($|y| <$ 0.5) in proton-proton collisions at $\\sqrt{s} = 7$ TeV performed with ALICE (A Large Ion Collider Experiment) at the Large Hadron Collider (LHC) is reported. Particle identification is performed using the specific ionization energy loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/$c$ for pions, from 0.2 up to 6 GeV/$c$ for kaons and from 0.3 up to 6 GeV/$c$ for protons. The measured spectra and particle ratios are compared with QCD-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

Crystal structure of bis-(3-bromo-pyridine-κN)bis-(O-ethyl di-thio-carbonato-κ(2) S,S')nickel(II).

Science.gov (United States)

Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

2015-01-01

In the title mol-ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni(2+) cation is located on a centre of inversion and has a distorted octa-hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C-S bond lengths of the thio-carboxyl-ate group are indicative of a delocalized bond and the O-Csp (2) bond is considerably shorter than the O-Csp (3) bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol-ecules is stabilized by C-H⋯S and C-H⋯π inter-actions. In addition, π-π inter-actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol-ecules are arranged in rows along [100], forming layers parallel to (010) and (001).

Poly[(6-carboxypicolinato-κ3O2,N,O6(μ3-pyridine-2,6-dicarboxylato-κ5O2,N,O6:O2′:O6′dysprosium(III

Directory of Open Access Journals (Sweden)

Xu Li

2009-11-01

Full Text Available In the title complex, [Dy(C7H3NO4(C7H4NO4]n, one of the ligands is fully deprotonated while the second has lost only one H atom. Each DyIII ion is coordinated by six O atoms and two N atoms from two pyridine-2,6-dicarboxylate and two 6-carboxypicolinate ligands, displaying a bicapped trigonal-prismatic geometry. The average Dy—O bond distance is 2.40 Å, some 0.1Å longer than the corresponding Ho—O distance in the isotypic holmium complex. Adjacent DyIII ions are linked by the pyridine-2,6-dicarboxylate ligands, forming a layer in (100. These layers are further connected by π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.827 (3 Å] and C—H...O hydrogen-bonding interactions, assembling a three-dimensional supramolecular network. Within each layer, there are other π–π stacking interactions between neighboring pyridyl rings [centroid–centroid distance = 3.501 (2 Å] and O—H...O and C—H...O hydrogen-bonding interactions, which further stabilize the structure.

Investigating the Effect of Pyridine Vapor Treatment on Perovskite Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Ong, Alison [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-08-20

Perovskite photovoltaics have recently come to prominence as a viable alternative to crystalline silicon based solar cells. In an effort to create consistent and high-quality films, we studied the effect of various annealing conditions as well as the effect of pyridine vapor treatment on mixed halide methylammonium lead perovskite films. Of six conditions tested, we found that annealing at 100°C for 90 minutes followed by 120°C for 15 minutes resulted in the purest perovskite. Perovskite films made using that condition were treated with pyridine for various amounts of time, and the effects on perovskite microstructure were studied using x-ray diffraction, UV-Vis spectroscopy, and time-resolved photoluminescence lifetime analysis (TRPL). A previous study found that pyridine vapor caused perovskite films to have higher photoluminescence intensity and become more homogenous. In this study we found that the effects of pyridine are more complex: while films appeared to become more homogenous, a decrease in bulk photoluminescence lifetime was observed. In addition, the perovskite bandgap appeared to decrease with increased pyridine treatment time. Finally, X-ray diffraction showed that pyridine vapor treatment increased the perovskite (110) peak intensity but also often gave rise to new unidentified peaks, suggesting the formation of a foreign species. It was observed that the intensity of this unknown species had an inverse correlation with the increase in perovskite peak intensity, and also seemed to be correlated with the decrease in TRPL lifetime.

Proton affinity of diastereoisomers of modified prolines using the kinetic method and density functional theory calculations: role of the cis/trans substituent on the endo/exo ring conformation.

Science.gov (United States)

Mezzache, S; Pepe, C; Karoyan, P; Fournier, F; Tabet, J-C

2005-01-01

The proton affinity (PA) of cis/trans-3-prolinoleucines and cis/trans-3-prolinoglutamic acids have been studied by the kinetic method and density functional theory (DFT) calculations. Several conformations of the neutral and the protonated modified prolines, in particular the endo and exo ring conformations, were analyzed with respect to their contribution to the PA values. When the substituent is an alkyl, both the diastereoisomers have the same PA value. However, the PA values for the diastereoisomers are different when the substituted chain contains functional groups (e.g. a carboxyl group). This variation in PA values could be attributed to the existence of intramolecular hydrogen bonds. Copyright (c) 2005 John Wiley & Sons, Ltd.

pyridine-carboxamide complexes

Indian Academy of Sciences (India)

(2a and 2b) in appreciable yields (L = L1 = N-(furan-2-ylmethyl)-2-pyridine carboxamide and L = L2 = ... able developments in a variety of catalytic transforma- .... Yield: 70–74%. (0.492 g); C22H20CdN6O8S2: Anal. Found: C, 39.13; H,. 2.91; N, 12.37; Cd, 16.64% Calc.: C, 39.26; H, 3.00; N,. Scheme 1. Reaction scheme.

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)

Rhodium(III)-Catalyzed ortho-Alkylation of Phenoxy Substrates with Diazo Compounds via C-H Activation: A Case of Decarboxylative Pyrimidine/Pyridine Migratory Cyclization Rather than Removal of Pyrimidine/Pyridine Directing Group.

Science.gov (United States)

Ravi, Manjula; Allu, Srinivasarao; Swamy, K C Kumara

2017-03-03

An efficient Rh(III)-catalyzed ortho-alkylation of phenoxy substrates with diazo compounds has been achieved for the first time using pyrimidine or pyridine as the directing group. Furthermore, bis-alkylation has also been achieved using para-substituted phenoxypyrimidine and 3 mol equiv of the diazo ester. The ortho-alkylated derivatives of phenoxy products possessing the ester functionality undergo decarboxylative pyrimidine/pyridine migratory cyclization (rather than deprotection of pyrimidine/pyridine group) using 20% NaOEt in EtOH affording a novel class of 3-(pyrimidin-2(1H)-ylidene)benzofuran-2(3H)-ones and 6-methyl-3-(pyridin-2(1H)-ylidene)benzofuran-2(3H)-one. The ortho-alkylated phenoxypyridine possessing ester functionality also undergoes decarboxylative pyridine migratory cyclization using MeOTf/NaOMe in toluene providing 6-methyl-3-(1-methylpyridin-2(1H)-ylidene)benzofuran-2(3H)-one.

ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS

International Nuclear Information System (INIS)

Wei, J.; Macek, R.J.

2002-01-01

One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures

NMR investigation of coal extracts

Energy Technology Data Exchange (ETDEWEB)

Lang, I; Sebor, G [Ceskoslovenska Akademie Ved, Prague. Hornicky Ustav; Sebor, G Jr; Hajek, M; Mostecky, J [Vysoka Skola Chemicko-Technologicka, Prague (Czechoslovakia)

1978-07-01

Proton NMR spectroscopy was used for the evaluation of 10% coal extract solutions in deuterated pyridine. Four types of Czechoslovak coal were analyzed. Agreement was found between the aromaticity of coal extracts calculated from /sup 1/H NMR data using Brown's method and Ladner's and Williams' method and the characterization of an average molecule of the coal extract by the number of non-bridge carbon atoms of aromatic rings, by the overall number of aromatic ring carbon atoms and the number of aromatic rings, determined by the Williams and Ferris methods. The methods for calculating carbon distribution from /sup 1/H NMR data, however, contain some constants theoretically estimated or experimentally found using the method which still remain to be verified.

Poly[tetraaqua-μ3-pyridine-3,5-dicarboxylato-strontium(II

Directory of Open Access Journals (Sweden)

Shirin Daneshvar

2008-02-01

Full Text Available The reaction of strontium(II nitrate with the proton-transfer compound (pdaH2(py-3,5-dc·H2O (where pda = propane-1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid leads to the formation of the title polymeric compound, [Sr(C7H3NO4(H2O4]n. The propane-1,3-diaminium cation is not incorporated in this crystal structure. The SrII atom lies on an inversion centre and is eight-coordinated by four O atoms from three py-3,5-dc ligands and four O atoms from four coordinated water molecules. The coordination polyhedron of the SrII atom is a distorted dodecahedron. These binuclear units are connected via the carboxylate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant interactions consisting of hydrogen bonds (X—H...O, with X = O and C and π–π stacking interactions [3.4604 (19 Å] connect the various components to form a supramolecular structure.

ULF waves associated with enhanced subauroral proton precipitation

Science.gov (United States)

Immel, Thomas J.; Mende, S. B.; Frey, H. U.; Patel, J.; Bonnell, J. W.; Engebretson, M. J.; Fuselier, S. A.

Several types of sub-auroral proton precipitation events have been identified using the Spectrographic Imager (SI) onboard the NASA-IMAGE satellite, including dayside subauroral proton flashes and detached proton arcs in the dusk sector. These have been observed at various levels of geomagnetic activity and solar wind conditions and the mechanism driving the precipitation has often been assumed to be scattering of protons into the loss cone by enhancement of ion-cyclotron waves in the interaction of the thermal plasmaspheric populations and more energetic ring current particles. Indeed, recent investigation of the detached arcs using the MPA instruments aboard the LANL geosynchronous satellites has shown there are nearly always heightened densities of cold plasma on high-altitude field lines which map down directly to the sub-auroral precipitation. If the ion-cyclotron instability is a causative mechanism, the enhancement of wave activity at ion-cyclotron frequencies should be measurable. It is here reported that magnetic pulsations in the Pc1 range occur in the vicinity of each of 4 detached arcs observed in 2000-2002, though with widely varying signatures. Additionally, longer period pulsations in the Pc5 ranges are also observed in the vicinity of the arcs, leading to the conclusion that a bounce-resonance of ring-current protons with the azimuthal Pc5 wave structure may also contribute to the detached precipitation.

On propagating direction of ring current proton ULF waves observed by ATS 6 at 6.6 R/sub e/

International Nuclear Information System (INIS)

Su, S.; Konradi, A.; Fritz, T.A.

1977-01-01

From June 11 to September 16, 1974, the NOAA low-energy proton detector on board the ATS 6 satellite observed 71 cases of ultralow-frequency oscillations of proton flux intensities. The oscillation periods varied from 40 s to 6 min, and the events were observed most frequently during moderate geomagnetic conditions. The flux oscillations occurred at various local times, yet almost two thirds of the events were detected in the near-dusk region of the magentosphere. For a majority of the events in this set a substantial phase shift in flux oscillation was detected between different energy channels and/or between two oppositely oriented detector telescopes. The phase shift is mainly due to the finite gyroradius effect of the protons gyrating in the geomagnetic field. By examining this finite gyroradius effect on the perturbed particle distribution function associated with the wave in a nonuniform magnetic field we are able to determine the propagation direction of the wave from particle observations made by a single spacecraft. Although the type of wave and its excitation mechanism can only be conjectured at the present time, it is concluded that the wave propagates in the westward direction with a phase velocity of about 13 km/s. Furthermore, it also has a very small phase velocity approx.0.15 km/s propagating toward the earth. If the wave had been traveling 1 hour or so before it was observed near the dusk magnetosphere, it might have originated in the dark magnetosphere in associating with some changes in geophysical conditions. The statistical correlation between the times of the observed wave events and the onsets of the auroral magnetic bays indicates that although they seldom occurred simultaneously, 80% of the waves were observed within 1 hour of the bay onset. Therefore it is concluded that the condition of the magnetosphere after a substorm is favorable for the occurrence of the ring current proton ultralow-frequency waves

Requirements of data acquisition and analysis for condensed matter studies at the weapons neutron research/proton storage ring facility

International Nuclear Information System (INIS)

Johnson, M.W.; Goldstone, J.A.; Taylor, A.D.

1982-11-01

With the completion of the proton storage ring (PSR) in 1985, the subsquent increase in neutron flux, and the continuing improvement in neutron scattering instruments, a significant improvement in data acquisition and data analysis capabilities will be required. A brief account of the neutron source is given together with the associated neutron scattering instruments. Based on current technology and operating instruments, a projection for 1985 to 1990 of the neutron scattering instruments and their main parameters are given. From the expected data rates and the projected instruments, the size of data storage is estimated and the user requirements are developed. General requirements are outlined with specific requirements in user hardware and software stated. A project time scale to complete the data acquisition and analysis system by 1985 is given

Progress on a prototype main ring rf cavity

International Nuclear Information System (INIS)

Swain, G.; Kandarian, R.; Thiessen, H.A.; Poirier, R.; Smythe, W.R.

1989-01-01

A prototype rf cavity and rf drive system for a hadron facility main ring has been designed and will be tested in the Proton Storage Ring (PSR) at Los Alamos as a part of a collaborative effort between LANL and TRIUMF. The cavity uses an orthogonally biased ferrite tuner. The design provides for accelerating gap voltages up to 200 kV for the 49.3 to 50.8 MHz range. Progress on the cavity construction and testing is described. 13 refs., 5 figs

Gold(III) complexes with 2-substituted pyridines as experimental anticancer agents: solution behavior, reactions with model proteins, antiproliferative properties.

Science.gov (United States)

Maiore, Laura; Cinellu, Maria Agostina; Nobili, Stefania; Landini, Ida; Mini, Enrico; Gabbiani, Chiara; Messori, Luigi

2012-03-01

Gold(III) compounds form a family of promising cytotoxic and potentially anticancer agents that are currently undergoing intense preclinical investigations. Four recently synthesized and characterized gold(III) derivatives of 2-substituted pyridines are evaluated here for their biological and pharmacological behavior. These include two cationic adducts with 2-pyridinyl-oxazolines, [Au(pyox(R))Cl(2)][PF(6)], [pyox(R)=(S)-4-benzyl-2-(pyridin-2-yl)-4,5-dihydrooxazole, I; (S)-4-iso-propyl-2-(pyridin-2-yl)-4,5-dihydrooxazole, II] and two neutral complexes [Au(N,N'OH)Cl(2)], III, and [Au(N,N',O)Cl], IV, containing the deprotonated ligand N-(1-hydroxy-3-iso-propyl-2-yl)pyridine-2-carboxamide, N,N'H,OH, resulting from ring opening of bound pyox(R) ligand of complex II by hydroxide ions. The solution behavior of these compounds was analyzed. These behave as classical prodrugs: activation of the metal center typically takes place through release of the labile chloride ligands while the rest of the molecule is not altered; alternatively, activation may occur through gold(III) reduction. All compounds react eagerly with the model protein cyt c leading to extensive protein metalation. ESI MS experiments revealed details of gold-cyt c interactions and allowed us to establish the nature of protein bound metal containing fragments. The different behavior displayed by I and II compared to III and IV is highlighted. Remarkable cytotoxic properties, against the reference human ovarian carcinoma cell lines A2780/S and A2780/R were disclosed for all tested compounds with IC(50) values ranging from 1.43 to 6.18 μM in the sensitive cell line and from 1.59 to 10.86 μM in the resistant one. The common ability of these compounds to overcome cisplatin resistance is highlighted. The obtained results are thoroughly discussed in the frame of current knowledge on cytotoxic gold compounds. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of magnetic non-linearities on a stored proton beam and their implications for superconducting storage rings

International Nuclear Information System (INIS)

Cornacchia, M.; Evans, L.

1985-06-01

A nonlinear lens may be used to study the effect of high-order multipolar field imperfections on a stored proton beam. Such a nonlinear lens is particulary suitable to simulate field imperfections of the types encountered in coil dominated superconducting magnets. We have studied experimentally at the SPS the effect of high order (5th and 8th) single isolated resonances driven by the nonlinear lens. The width of these resonances is of the order one expects to be caused by field errors in superconducting magnets of the SSC type. The experiment shows that, in absence of tune modulation, these resonances are harmless. Slow crossings of the resonance, on the other hand, have destructive effects on the beam, much more so than fast crossings caused by synchrotron oscillations. In the design of future storage rings, sources of low-frequency tune modulation should be avoided as a way to reduce the harmful effects of high order multipolar field imperfection

A two-dimensional CdII coordination polymer: poly[diaqua[μ3-5,6-bis(pyridin-2-ylpyrazine-2,3-dicarboxylato-κ5O2:O3:O3,N4,N5]cadmium

Directory of Open Access Journals (Sweden)

Monserrat Alfonso

2016-09-01

Full Text Available The reaction of 5,6-bis(pyridin-2-ylpyrazine-2,3-dicarboxylic acid with cadmium dichloride leads to the formation of the title two-dimensional coordination polymer, [Cd(C16H8N4O4(H2O2]n. The metal atom is sevenfold coordinated by one pyrazine and one pyridine N atom, two water O atoms, and by two carboxylate O atoms, one of which bridges two CdII atoms to form a Cd2O2 unit situated about a centre of inversion. Hence, the ligand coordinates to the cadmium atom in an N,N′,O-tridentate and an O-monodentate manner. Within the polymer network, there are a number of O—H...O hydrogen bonds present, involving the water molecules and the carboxylate O atoms. There are also C—H...N and C—H...O hydrogen bonds present. In the crystal, the polymer networks lie parallel to the bc plane. They are aligned back-to-back along the a axis with the non-coordinating pyridine rings directed into the space between the networks.

Radiation conditions in the ring hall of the IHEP proton synchrotron

International Nuclear Information System (INIS)

Borodin, V.E.; Ermolenko, L.S.; Obryashchikova, L.P.

1975-01-01

The paper presents the results on studying the radiation conditions caused by induced radioactivity of the accelerator units in the ring hall. The data on the induced radioactivity level just on the ring vacuum chamber are reported. Radiation conditions in the most characteristic areas of the hall are considered. The changes in time of the dose rate at the internal target and at the entrance to the hall are shown

Dual ring multilayer ionization chamber and theory-based correction technique for scanning proton therapy.

Science.gov (United States)

Takayanagi, Taisuke; Nihongi, Hideaki; Nishiuchi, Hideaki; Tadokoro, Masahiro; Ito, Yuki; Nakashima, Chihiro; Fujitaka, Shinichiro; Umezawa, Masumi; Matsuda, Koji; Sakae, Takeji; Terunuma, Toshiyuki

2016-07-01

To develop a multilayer ionization chamber (MLIC) and a correction technique that suppresses differences between the MLIC and water phantom measurements in order to achieve fast and accurate depth dose measurements in pencil beam scanning proton therapy. The authors distinguish between a calibration procedure and an additional correction: 1-the calibration for variations in the air gap thickness and the electrometer gains is addressed without involving measurements in water; 2-the correction is addressed to suppress the difference between depth dose profiles in water and in the MLIC materials due to the nuclear interaction cross sections by a semiempirical model tuned by using measurements in water. In the correction technique, raw MLIC data are obtained for each energy layer and integrated after multiplying them by the correction factor because the correction factor depends on incident energy. The MLIC described here has been designed especially for pencil beam scanning proton therapy. This MLIC is called a dual ring multilayer ionization chamber (DRMLIC). The shape of the electrodes allows the DRMLIC to measure both the percentage depth dose (PDD) and integrated depth dose (IDD) because ionization electrons are collected from inner and outer air gaps independently. IDDs for which the beam energies were 71.6, 120.6, 159, 180.6, and 221.4 MeV were measured and compared with water phantom results. Furthermore, the measured PDDs along the central axis of the proton field with a nominal field size of 10 × 10 cm(2) were compared. The spread out Bragg peak was 20 cm for fields with a range of 30.6 and 3 cm for fields with a range of 6.9 cm. The IDDs measured with the DRMLIC using the correction technique were consistent with those that of the water phantom; except for the beam energy of 71.6 MeV, all of the points satisfied the 1% dose/1 mm distance to agreement criterion of the gamma index. The 71.6 MeV depth dose profile showed slight differences in the shallow

Accumulator ring lattice for the national spallation neutron source

International Nuclear Information System (INIS)

Gardner, C.J.; Lee, Y.Y.; Luccio, A.U.

1997-01-01

The Accumulator Ring for the proposed National Spallation Neutron Source (NSNS) is to accept a 1.03 millisecond beam pulse from a 1 GeV Proton Linac at a repetition rate of 60 Hz. For each beam pulse, 10 14 protons are to be accumulated via charge-exchange injection. A 295 nanosecond gap in the beam, maintained by an rf system, will allow for extraction to an external target for the production of neutrons by spallation. This paper describes the four-fold symmetric lattice that has been chosen for the ring. The lattice contains four long dispersion-free straight sections to accomodate injection, extraction, rf cavities, and beam scraping respectively. The four-fold symmetry allows for easy adjustment of the tunes and flexibility in the placement of correction elements, and ensures that potentially dangerous betatron structure resonances are avoided

Correlations between high momentum particles in proton-proton collisions at high energies

International Nuclear Information System (INIS)

Bobbink, G.J.

1981-01-01

This thesis describes an experiment performed at the CERN Intersecting Storage Rings. The experiment studies the reaction p+p→h 1 +h 2 +X at two centre-of-mass energies, √s=44.7 GeV and √s=62.3 GeV. Two of the outgoing particles (h 1 and h 2 ) are detected in opposite c.m.s. hemispheres at small polar angles with respect to the direction of two incident protons. The remaining particles produced (X) are not detected. The hadrons hsub(i) are identified mesons (π + , π - , K + , K - ) or baryons (p, Λ) with relatively large longitudinal psub(L) and small transverse momentum psub(T). The aim of the experiment is twofold. The first aim is to study whether the momentum distributions of the fast particles hsub(i) are correlated and thereby to constrain the possible interaction mechanisms responsible for the production of high psub(L), low psub(T) particles. The second aim is to establish to what extent the production of pions and kaons in inclusive proton-proton collisions (e.g. p+p→π+X, X=all other particles) resembles the production of pions and kaons in diffractive proton-proton collisions (e.g. p+p→p+π+X, in which the final-state proton has a momentum close to its maximum possible value). (Auth.)

Amide proton temperature coefficients as hydrogen bond indicators in proteins

International Nuclear Information System (INIS)

Cierpicki, Tomasz; Otlewski, Jacek

2001-01-01

Correlations between amide proton temperature coefficients (Δσ HN /ΔT) and hydrogen bonds were investigated for a data set of 793 amides derived from 14 proteins. For amide protons showing temperature gradients more positive than -4.6 ppb/K there is a hydrogen bond predictivity value exceeding 85%. It increases to over 93% for amides within the range between -4 and -1 ppb/K. Detailed analysis shows an inverse proportionality between amide proton temperature coefficients and hydrogen bond lengths. Furthermore, for hydrogen bonds of similar bond lengths, values of temperature gradients in α-helices are on average 1 ppb/K more negative than in β-sheets. In consequence, a number of amide protons in α-helices involved in hydrogen bonds shorter than 2 A show Δσ HN /ΔT 10 helices and 98% in β-turns have temperature coefficients more positive than -4.6ppb/K. Ring current effect also significantly influences temperature coefficients of amide protons. In seven out of eight cases non-hydrogen bonded amides strongly deshielded by neighboring aromatic rings show temperature coefficients more positive than -2 ppb/K. In general, amide proton temperature gradients do not change with pH unless they correspond to conformational changes. Three examples of pH dependent equilibrium showing hydrogen bond formation at higher pH were found. In conclusion, amide proton temperature coefficients offer an attractive and simple way to confirm existence of hydrogen bonds in NMR determined structures

Hexaaquanickel(II tetraaquabis(μ-pyridine-2,6-dicarboxylatobis(pyridine-2,6-dicarboxylatotrinickelate(II octahydrate

Directory of Open Access Journals (Sweden)

Javad Safaei-Ghomi

2010-08-01

Full Text Available The title compound, [Ni(H2O6][Ni3(C7H3NO44(H2O4]·8H2O, was obtained by the reaction of nickel(II nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2 and 1,10-phenanothroline (phen in an aqueous solution. The latter ligand is not involved in formation of the title complex. There are three different NiII atoms in the asymmetric unit, two of which are located on inversion centers, and thus the [Ni(H2O6]2+ cation and the trinuclear {[Ni(pydc2]2-μ-Ni(H2O4}2− anion are centrosymmetric. All NiII atoms exhibit an octahedral coordination geometry. Various interactions, including numerous O—H...O and C—H...O hydrogen bonds and C—O...π stacking of the pyridine and carboxylate groups [3.570 (1, 3.758 (1 and 3.609 (1 Å], are observed in the crystal structure.

Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV.

Science.gov (United States)

Adam, J; Adamová, D; Aggarwal, M M; Rinella, G Aglieri; Agnello, M; Agrawal, N; Ahammed, Z; Ahmed, I; Ahn, S U; Aimo, I; Aiola, S; Ajaz, M; Akindinov, A; Alam, S N; Aleksandrov, D; Alessandro, B; Alexandre, D; Molina, R Alfaro; Alici, A; Alkin, A; Alme, J; Alt, T; Altinpinar, S; Altsybeev, I; Prado, C Alves Garcia; Andrei, C; Andronic, A; Anguelov, V; Anielski, J; Antičić, T; Antinori, F; Antonioli, P; Aphecetche, L; Appelshäuser, H; Arcelli, S; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Arslandok, M; Augustinus, A; Averbeck, R; Azmi, M D; Bach, M; Badalà, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bala, R; Baldisseri, A; Ball, M; Pedrosa, F Baltasar Dos Santos; Baral, R C; Barbano, A M; Barbera, R; Barile, F; Barnaföldi, G G; Barnby, L S; Barret, V; Bartalini, P; Bartke, J; Bartsch, E; Basile, M; Bastid, N; Basu, S; Bathen, B; Batigne, G; Camejo, A Batista; Batyunya, B; Batzing, P C; Bearden, I G; Beck, H; Bedda, C; Behera, N K; Belikov, I; Bellini, F; Martinez, H Bello; Bellwied, R; 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Grinyov, B; Grion, N; Grosse-Oetringhaus, J F; Grossiord, J-Y; Grosso, R; Guber, F; Guernane, R; Guerzoni, B; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Haake, R; Haaland, Ø; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Hanratty, L D; Hansen, A; Harris, J W; Hartmann, H; Harton, A; Hatzifotiadou, D; Hayashi, S; Heckel, S T; Heide, M; Helstrup, H; Herghelegiu, A; Corral, G Herrera; Hess, B A; Hetland, K F; Hilden, T E; Hillemanns, H; Hippolyte, B; Hristov, P; Huang, M; Humanic, T J; Hussain, N; Hussain, T; Hutter, D; Hwang, D S; Ilkaev, R; Ilkiv, I; Inaba, M; Ionita, C; Ippolitov, M; Irfan, M; Ivanov, M; Ivanov, V; Izucheev, V; Jacobs, P M; Jahnke, C; Jang, H J; Janik, M A; Jayarathna, P H S Y; Jena, C; Jena, S; Bustamante, R T Jimenez; Jones, P G; Jung, H; Jusko, A; Kalinak, P; Kalweit, A; Kamin, J; Kang, J H; Kaplin, V; Kar, S; Uysal, A Karasu; Karavichev, O; Karavicheva, T; Karpechev, E; Kebschull, U; Keidel, R; Keijdener, D L D; Keil, M; Khan, K H; Khan, M M; Khan, P; Khan, S A; Khanzadeev, A; Kharlov, Y; Kileng, B; Kim, B; Kim, D W; Kim, D J; Kim, H; Kim, J S; Kim, M; Kim, M; Kim, S; Kim, T; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Kiss, G; Klay, J L; Klein, C; Klein, J; Klein-Bösing, C; Kluge, A; Knichel, M L; Knospe, A G; Kobayashi, T; Kobdaj, C; Kofarago, M; Köhler, M K; Kollegger, T; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Kondratyuk, E; Konevskikh, A; Kouzinopoulos, C; Kovalenko, O; Kovalenko, V; Kowalski, M; Kox, S; Meethaleveedu, G Koyithatta; Kral, J; Králik, I; Kravčáková, A; Krelina, M; Kretz, M; Krivda, M; Krizek, F; Kryshen, E; Krzewicki, M; Kubera, A M; Kučera, V; Kucheriaev, Y; Kugathasan, T; Kuhn, C; Kuijer, P G; Kulakov, I; Kumar, J; Kumar, L; Kurashvili, P; Kurepin, A; Kurepin, A B; Kuryakin, A; Kushpil, S; Kweon, M J; Kwon, Y; Pointe, S L La; Rocca, P La; Fernandes, C Lagana; Lakomov, I; Langoy, R; Lara, C; Lardeux, A; Lattuca, A; Laudi, E; Lea, R; Leardini, L; Lee, G R; Lee, S; Legrand, I; Lehnert, J; Lemmon, R C; Lenti, V; Leogrande, E; Monzón, I León; Leoncino, M; Lévai, P; Li, S; Li, X; Lien, J; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Ljunggren, H M; Lodato, D F; Loenne, P I; Loggins, V R; Loginov, V; Loizides, C; Lopez, X; Torres, E López; Lowe, A; Lu, X-G; Luettig, P; Lunardon, M; Luparello, G; Maevskaya, A; Mager, M; Mahajan, S; Mahmood, S M; Maire, A; Majka, R D; Malaev, M; Cervantes, I Maldonado; Malinina, L; Mal'Kevich, D; Malzacher, P; Mamonov, A; Manceau, L; Manko, V; Manso, F; Manzari, V; Marchisone, M; Mareš, J; Margagliotti, G V; Margotti, A; Margutti, J; Marín, A; Markert, C; Marquard, M; Martin, N A; Blanco, J Martin; Martinengo, P; Martínez, M I; Martínez García, G; Pedreira, M Martinez; Martynov, Y; Mas, A; Masciocchi, S; Masera, M; Masoni, A; Massacrier, L; Mastroserio, A; Masui, H; Matyja, A; Mayer, C; Mazer, J; Mazzoni, M A; Mcdonald, D; Meddi, F; Menchaca-Rocha, A; Meninno, E; Pérez, J Mercado; Meres, M; Miake, Y; Mieskolainen, M M; Mikhaylov, K; Milano, L; Milosevic, J; Minervini, L M; Mischke, A; Mishra, A N; Miśkowiec, D; Mitra, J; Mitu, C M; Mohammadi, N; Mohanty, B; Molnar, L; Zetina, L Montaño; Montes, E; Morando, M; Godoy, D A Moreira De; Moretto, S; Morreale, A; Morsch, A; Muccifora, V; Mudnic, E; Mühlheim, D; Muhuri, S; Mukherjee, M; Müller, H; Mulligan, J D; Munhoz, M G; Murray, S; Musa, L; Musinsky, J; Nandi, B K; Nania, R; Nappi, E; Naru, M U; Nattrass, C; Nayak, K; Nayak, T K; Nazarenko, S; Nedosekin, A; Nellen, L; Ng, F; Nicassio, M; Niculescu, M; Niedziela, J; Nielsen, B S; Nikolaev, S; Nikulin, S; Nikulin, V; Noferini, F; Nomokonov, P; Nooren, G; Norman, J; Nyanin, A; Nystrand, J; Oeschler, H; Oh, S; Oh, S K; Ohlson, A; Okatan, A; Okubo, T; Olah, L; Oleniacz, J; Silva, A C Oliveira Da; Oliver, M H; Onderwaater, J; Oppedisano, C; Velasquez, A Ortiz; Oskarsson, A; Otwinowski, J; Oyama, K; Ozdemir, M; Pachmayer, Y; Pagano, P; Paić, G; Pajares, C; Pal, S K; Pan, J; Pandey, A K; Pant, D; Papikyan, V; Pappalardo, G S; Pareek, P; Park, W J; Parmar, S; 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Riggi, F; Ristea, C; Rivetti, A; Rocco, E; Cahuantzi, M Rodríguez; Manso, A Rodriguez; Røed, K; Rogochaya, E; Rohr, D; Röhrich, D; Romita, R; Ronchetti, F; Ronflette, L; Rosnet, P; Rossi, A; Roukoutakis, F; Roy, A; Roy, C; Roy, P; Montero, A J Rubio; Rui, R; Russo, R; Ryabinkin, E; Ryabov, Y; Rybicki, A; Sadovsky, S; Šafařík, K; Sahlmuller, B; Sahoo, P; Sahoo, R; Sahoo, S; Sahu, P K; Saini, J; Sakai, S; Saleh, M A; Salgado, C A; Salzwedel, J; Sambyal, S; Samsonov, V; Castro, X Sanchez; Šándor, L; Sandoval, A; Sano, M; Santagati, G; Sarkar, D; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schmidt, C; Schmidt, H R; Schuchmann, S; Schukraft, J; Schulc, M; Schuster, T; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, R; Seeder, K S; Seger, J E; Sekiguchi, Y; Selyuzhenkov, I; Senosi, K; Seo, J; Serradilla, E; Sevcenco, A; Shabanov, A; Shabetai, A; Shadura, O; Shahoyan, R; Shangaraev, A; Sharma, A; Sharma, N; Shigaki, K; Shtejer, K; Sibiriak, Y; Siddhanta, S; Sielewicz, K M; Siemiarczuk, T; Silvermyr, D; Silvestre, C; Simatovic, G; Simonetti, G; Singaraju, R; Singh, R; Singha, S; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Slupecki, M; Smirnov, N; Snellings, R J M; Snellman, T W; Søgaard, C; Soltz, R; Song, J; Song, M; Song, Z; Soramel, F; Sorensen, S; Spacek, M; Spiriti, E; Sputowska, I; Stassinaki, M Spyropoulou; Srivastava, B K; Stachel, J; Stan, I; Stefanek, G; Steinpreis, M; Stenlund, E; Steyn, G; Stiller, J H; Stocco, D; Strmen, P; Suaide, A A P; Sugitate, T; Suire, C; Suleymanov, M; Sultanov, R; Šumbera, M; Symons, T J M; Szabo, A; Toledo, A Szanto de; Szarka, I; Szczepankiewicz, A; Szymanski, M; Takahashi, J; Tanaka, N; Tangaro, M A; Takaki, J D Tapia; Peloni, A Tarantola; Tariq, M; Tarzila, M G; Tauro, A; Muñoz, G Tejeda; Telesca, A; Terasaki, K; Terrevoli, C; Teyssier, B; Thäder, J; Thomas, D; Tieulent, R; Timmins, A R; Toia, A; Trogolo, S; Trubnikov, V; Trzaska, W H; Tsuji, T; Tumkin, A; Turrisi, R; Tveter, T S; Ullaland, K; Uras, A; Usai, G L; Utrobicic, A; Vajzer, M; Vala, M; Palomo, L Valencia; Vallero, S; Maarel, J Van Der; Hoorne, J W Van; Leeuwen, M van; Vanat, T; Vyvre, P Vande; Varga, D; Vargas, A; Vargyas, M; Varma, R; Vasileiou, M; Vasiliev, A; Vauthier, A; Vechernin, V; Veen, A M; Veldhoen, M; Velure, A; Venaruzzo, M; Vercellin, E; Limón, S Vergara; Vernet, R; Verweij, M; Vickovic, L; Viesti, G; Viinikainen, J; Vilakazi, Z; Baillie, O Villalobos; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Vislavicius, V; Viyogi, Y P; Vodopyanov, A; Völkl, M A; Voloshin, K; Voloshin, S A; Volpe, G; Haller, B von; Vorobyev, I; Vranic, D; Vrláková, J; Vulpescu, B; Vyushin, A; Wagner, B; Wagner, J; Wang, H; Wang, M; Wang, Y; Watanabe, D; Weber, M; Weber, S G; Wessels, J P; Westerhoff, U; Wiechula, J; Wikne, J; Wilde, M; Wilk, G; Wilkinson, J; Williams, M C S; Windelband, B; Winn, M; Yaldo, C G; Yamaguchi, Y; Yang, H; Yang, P; Yano, S; Yasnopolskiy, S; Yin, Z; Yokoyama, H; Yoo, I-K; Yurchenko, V; Yushmanov, I; Zaborowska, A; Zaccolo, V; Zaman, A; Zampolli, C; Zanoli, H J C; Zaporozhets, S; Zarochentsev, A; Závada, P; Zaviyalov, N; Zbroszczyk, H; Zgura, I S; Zhalov, M; Zhang, H; Zhang, X; Zhang, Y; Zhao, C; Zhigareva, N; Zhou, D; Zhou, Y; Zhou, Z; Zhu, H; Zhu, J; Zhu, X; Zichichi, A; Zimmermann, A; Zimmermann, M B; Zinovjev, G; Zyzak, M

The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

E-P instability in the NSNS accumulator ring

Energy Technology Data Exchange (ETDEWEB)

Ruggiero, A.G.; Blaskiewicz, M.

1997-08-01

It has been speculated that the intensity limitation observed in the Los Alamos Proton Storage Ring (PSR) is caused by a coherent instability induced by the presence of pockets of electrons generated by scattering with the molecules of the vacuum residual gas. A theoretical explanation of the e-p instability of course does exist, and is similar to the one developed for the ion-induced instability in electron storage rings. Considering the large beam power (3 MW) involved in the NSNS Accumulator Ring, and the consequences caused by even a small amount of beam loss, we need to carefully assess the effects of electrons that may be generated in the vacuum chamber.

Synthesis of a novel class of some biquinoline pyridine hybrids via

Indian Academy of Sciences (India)

A small library of novel class of biquinoline containing pyridine moiety were synthesized by a one-pot cyclocondensation of 2-chloro-3-formyl quinoline, active methylene compounds and 3-(pyridine-3- ylamino)cyclohex-2-enone in the presence of catalytic amount of sodium hydroxide. The protocol offers rapid synthesis of ...

State of development of CERN proton storage rings

CERN Document Server

Huber, H

1973-01-01

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

Determination of pyridine in soil and water samples of a polluted area

International Nuclear Information System (INIS)

Peters, R.J.B.; Renesse van Duivenbode, J.A.D. van

1994-01-01

A method for the analyses of pyridine in environmental samples is described. For soil samples a distillation procedure followed by an extraction, an acidic extraction or a Soxhlet extraction can be used. For water samples a distillation procedure followed by extraction can be employed. Deuterated pyridine is used as an internal standard and the extracts are analyzed by GC-MS. The recoveries of the methods are higher than 80%; the detection limits for pyridine are 0.01 mg/kg for soil samples and 0.2 μg/l for water samples. (orig.)

SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

Science.gov (United States)

Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

2011-02-01

As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

The merging of the Intersecting Storage Rings for a 60 GeV collider with the 400 GeV proton synchrotron

International Nuclear Information System (INIS)

1978-01-01

Following the recommendation of the Workshop on Future ISR Physics, 1976, a study has been made of using the existing ISR (Intersecting Storage Rings) equipment at CERN to build a single 60 GeV storage ring (Merged ISR) for beam collision with the 400 GeV Super Proton Synchrotron (SPS). At a minimum cost of 103 MSF, a single-intersection physics facility with a 3.55 0 crossing angle, a luminosity of 1.2 10 30 cm -2 s -1 and a centre-of-mass energy of 255 GeV could be built. For a further 7 MSF, the luminosity could be easily raised to 3.8 10 30 cm -2 s -1 . Alternatively, the MISR can be built to give a single, zero-angle crossing with a luminosity of 1.1 10 32 cm -2 s -1 . The last solution is not recommended, however, as the free space around the intersection is extremely limited and the facility becomes very specialized in the type of physics experiments which could be performed. In all cases, the project could be completed in three years and two months with a 9 1/2-month shutdown for the SPS and 18 months between the closing down of the ISR and the start-up of MISR. (Auth.)

Molecular Dynamics and Neutron Scattering Studies of Mixed Solutions of Caffeine and Pyridine in Water.

Science.gov (United States)

Tavagnacco, Letizia; Mason, Philip E; Neilson, George W; Saboungi, Marie-Louise; Cesàro, Attilio; Brady, John W

2018-05-31

Insight into the molecular interactions of homotactic and heterotactic association of caffeine and pyridine in aqueous solution is given on the basis of both experimental and simulation studies. Caffeine is about 5 times more soluble in a 3 m aqueous pyridine solution than it is in pure water (an increase from ∼0.1 m to 0.5 m). At this elevated concentration the system becomes suitable for neutron scattering study. Caffeine-pyridine interactions were studied by neutron scattering and molecular dynamics simulations, allowing a detailed characterization of the spatial and orientational structure of the solution. It was found that while pyridine-caffeine interactions are not as strong as caffeine-caffeine interactions, the pyridine-caffeine interactions still significantly disrupted caffeine-caffeine stacking. The alteration of the caffeine-caffeine stacking, occasioned by the presence of pyridine molecules in solution and the consequent formation of heterotactic interactions, leads to the experimentally detected increase in caffeine solubility.

ELECTRON CLOUD EFFECTS IN HIGH INTENSITY PROTON ACCELERATORS.

Energy Technology Data Exchange (ETDEWEB)

WEI,J.; MACEK,R.J.

2002-04-14

One of the primary concerns in the design and operation of high-intensity proton synchrotrons and accumulators is the electron cloud and associated beam loss and instabilities. Electron-cloud effects are observed at high-intensity proton machines like the Los Alamos National Laboratory's PSR and CERN's SPS, and investigated experimentally and theoretically. In the design of next-generation high-intensity proton accelerators like the Spallation Neutron Source ring, emphasis is made in minimizing electron production and in enhancing Landau damping. This paper reviews the present understanding of the electron-cloud effects and presents mitigation measures.

Crystal structure of a new monoclinic polymorph of N-(4-methyl-phen-yl)-3-nitro-pyridin-2-amine.

Science.gov (United States)

Aznan, Aina Mardia Akhmad; Abdullah, Zanariah; Lee, Vannajan Sanghiran; Tiekink, Edward R T

2014-08-01

The title compound, C12H11N3O2, is a second monoclinic polymorph (P21, with Z' = 4) of the previously reported monoclinic (P21/c, with Z' = 2) form [Akhmad Aznan et al. (2010 ▶). Acta Cryst. E66, o2400]. Four independent mol-ecules comprise the asymmetric unit, which have the common features of a syn disposition of the pyridine N atom and the toluene ring, and an intra-molecular amine-nitro N-H⋯O hydrogen bond. The differences between mol-ecules relate to the dihedral angles between the rings which range from 2.92 (19) to 26.24 (19)°. The geometry-optimized structure [B3LYP level of theory and 6-311 g+(d,p) basis set] has the same features except that the entire mol-ecule is planar. In the crystal, the three-dimensional architecture is consolidated by a combination of C-H⋯O, C-H⋯π, nitro-N-O⋯π and π-π inter-actions [inter-centroid distances = 3.649 (2)-3.916 (2) Å].

Quantum Mechanics/Molecular Mechanics Simulations Identify the Ring-Opening Mechanism of Creatininase.

Science.gov (United States)

Jitonnom, Jitrayut; Mujika, Jon I; van der Kamp, Marc W; Mulholland, Adrian J

2017-12-05

Creatininase catalyzes the conversion of creatinine (a biosensor for kidney function) to creatine via a two-step mechanism: water addition followed by ring opening. Water addition is common to other known cyclic amidohydrolases, but the precise mechanism for ring opening is still under debate. The proton donor in this step is either His178 or a water molecule bound to one of the metal ions, and the roles of His178 and Glu122 are unclear. Here, the two possible reaction pathways have been fully examined by means of combined quantum mechanics/molecular mechanics simulations at the SCC-DFTB/CHARMM22 level of theory. The results indicate that His178 is the main catalytic residue for the whole reaction and explain its role as proton shuttle during the ring-opening step. In the first step, His178 provides electrostatic stabilization to the gem-diolate tetrahedral intermediate. In the second step, His178 abstracts the hydroxyl proton of the intermediate and delivers it to the cyclic amide nitrogen, leading to ring opening. The latter is the rate-limiting step with a free energy barrier of 18.5 kcal/mol, in agreement with the experiment. We find that Glu122 must be protonated during the enzyme reaction, so that it can form a stable hydrogen bond with its neighboring water molecule. Simulations of the E122Q mutant showed that this replacement disrupts the H-bond network formed by three conserved residues (Glu34, Ser78, and Glu122) and water, increasing the energy barrier. Our computational studies provide a comprehensive explanation for previous structural and kinetic observations, including why the H178A mutation causes a complete loss of activity but the E122Q mutation does not.

(Z)-N,N-Dimethyl-2-[phen­yl(pyridin-2-yl)methyl­idene]hydrazinecarbothio­amide

Science.gov (United States)

Jayakumar, K.; Sithambaresan, M.; Prathapachandra Kurup, M. R.

2011-01-01

The title compound, C15H16N4S, exists in the Z conformation with the thionyl S atom lying cis to the azomethine N atom. The shortening of the N—N distance [1.3697 (17) Å] is due to extensive delocalization with the pyridine ring. The hydrazine–carbothio­amide unit is almost planar, with a maximum deviation of 0.013 (2) Å for the amide N atom. The stability of this conformation is favoured by the formation of an intra­molecular N—H⋯N hydrogen bond. The packing of the mol­ecules involves no classical inter­molecular hydrogen-bonding inter­actions; however, a C—H⋯π inter­action occurs. PMID:22199715

Complexation of imidazopyridine-based cations with a 24-crown-8 ether host: [2]pseudorotaxane and partially threaded structures.

Science.gov (United States)

Moreno-Olivares, Surisadai I; Cervantes, Ruy; Tiburcio, Jorge

2013-11-01

A new series of linear molecules derived from 1,2-bis(imidazopyridin-2-yl)ethane can fully or partially penetrate the cavity of the dibenzo-24-crown-8 macrocycle to produce a new family of host-guest complexes. Protonation or alkylation of the nitrogen atoms on the pyridine rings led to an increase in the guest total positive charge up to 4+ and simultaneously generated two new recognition sites (pyridinium motifs) that are in competition with the 1,2-bis(benzimidazole)ethane motif for the crown ether. The relative position of the pyridine ring and the chemical nature of the N-substituent determined the preferred motif and the host-guest complex geometry: (i) for linear guests with relatively bulky groups (i.e., a benzyl substituent), the 1,2-bis(benzimidazole)ethane motif is favored, leading to a fully threaded complex with a [2]pseudorotaxane geometry; (ii) for small substituents, such as -H and -CH3 groups, regardless of the guest shape, the pyridinium motifs are preferred, leading to external partially threaded complexes in a 2:1 host to guest stoichiometry.

Removal of pyridine from liquid and gas phase by copper forms of natural and synthetic zeolites

International Nuclear Information System (INIS)

Rehakova, Maria; Fortunova, Lubica; Bastl, Zdenek; Nagyova, Stanislava; Dolinska, Silvia; Jorik, Vladimir; Jona, Eugen

2011-01-01

Zeoadsorbents on the basis of copper forms of synthetic zeolite ZSM5 and natural zeolite of the clinoptilolite type (CT) have been studied taking into account their environmental application in removing harmful pyridine (py) from liquid and gas phase. Sorption of pyridine by copper forms of zeolites (Cu-ZSM5 and Cu-CT) has been studied by CHN, X-ray photoelectron spectroscopy, X-ray powder diffractometry, FTIR spectroscopy, thermal analysis (TG, DTA and DTG) and analysis of the surface areas and the pore volumes by low-temperature adsorption of nitrogen. The results of thermal analyses of Cu-ZSM5, Cu-(py) x ZSM5, Cu-CT and Cu-(py) x CT zeolitic products with different composition (x depends on the experimental conditions of sorption of pyridine) clearly confirmed their different thermal properties as well as the sorption of pyridine. In the zeolitic pyridine containing samples the main part of the pyridine release process occurs at considerably higher temperatures than is the boiling point of pyridine, which proves strong bond and irreversibility of py-zeolite interaction. FTIR spectra of Cu-(py) x zeolite samples showed well resolved bands of pyridine. The results of thermal analysis and FTIR spectroscopy are in a good agreement with the results of other used methods.

Hydrogen trapping ability of the pyridine-lithium⁺ (1:1) complex.

Science.gov (United States)

Chattaraj, Saparya; Srinivasu, K; Mondal, Sukanta; Ghosh, Swapan K

2015-03-26

Theoretical studies have been carried out at different levels of theory to verify the hydrogen adsorption characteristics of pyridine-lithium ion (1:1) complexes. The nature of interactions associated with the bonding between pyridine and lithium as well as that between lithium and adsorbed molecular hydrogen is studied through the calculation of electron density and electron-density-based reactivity descriptors. The pyridine-lithium ion complex has been hydrogenated systematically around the lithium site, and each lithium site is found to adsorb a maximum of four hydrogen molecules with an interaction energy of ∼-4.0 kcal/mol per molecule of H2. The fate of the hydrogen adsorbed in a pyridine-lithium ion complex (corresponding to the maximum adsorption) is studied in the course of a 2 ps time evolution through ab initio molecular dynamics simulation at different temperatures. The results reveal that the complex can hold a maximum of four hydrogen molecules at a temperature of 77 K, whereas it can hold only two molecules of hydrogen at 298 K.

The PEP electron-positron ring

International Nuclear Information System (INIS)

Rees, J.R.

1988-01-01

The first stage of the positron-electron-proton (PEP) colliding-beam system which has been under joint study by a Lawrence Berkeley Laboratory-Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e + e/sup minus/ ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus at the intersection regions will be 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup minus 2/s/sup minus 1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross-section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described

Pyridine-substituted thiazolylphenol derivatives: Synthesis, modeling studies, aromatase inhibition, and antiproliferative activity evaluation.

Science.gov (United States)

Ertas, Merve; Sahin, Zafer; Berk, Barkin; Yurttas, Leyla; Biltekin, Sevde N; Demirayak, Seref

2018-04-01

Drugs used in breast cancer treatments target the suppression of estrogen biosynthesis. During this suppression, the main goal is to inhibit the aromatase enzyme that is responsible for the cyclization and structuring of estrogens either with steroid or non-steroidal-type inhibitors. Non-steroidal derivatives generally have a planar aromatic structure attached to the triazole ring system in their structures, which inhibits hydroxylation reactions during aromatization by coordinating the heme group. Bioisosteric replacement of the triazole ring system and development of aromatic/cyclic structures of the side chain can increase the selectivity for aromatase enzyme inhibition. In this study, pyridine-substituted thiazolylphenol derivatives, which are non-steroidal triazole bioisosteres, were synthesized using the Hantzsch method, and physical analysis and structural determination studies were performed. The IC 50 values of the compounds were determined by a fluorescence-based aromatase inhibition assay. Then, their antiproliferative activities on the MCF7 and HEK 293 cell lines were evaluated with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, the crystal structure of human placental aromatase was subjected to a series of docking experiments to identify the possible interactions between the most active structure and the active site. Lastly, an in silico technique was performed to analyze and predict the drug-likeness, molecular and ADME properties of the synthesized molecules. © 2018 Deutsche Pharmazeutische Gesellschaft.

9-Furfurylidene-2,3-dimethyl-6,7,8,9-tetrahydro-4H-thieno[2′,3′:4,5]pyrimidino[1,2-a]pyridin-4-one

Directory of Open Access Journals (Sweden)

Khusnutdin M. Shakhidoyatov

2010-03-01

Full Text Available The title compound, C17H16N2O2S, was obtained by condensation of 2,3-dimethylthieno[2′,3′:4,5]pyrimidino[1,2-a]pyridin-4-one with furfural in the presence of sodium hydroxide. One of the methylene groups of the tetrahydropyrido ring is disordered over two positions in a 0.87 (1:0.13 (1 ratio. The thieno[2,3-d]pyrimidin-4-one unit and the furan ring are both planar (r.m.s. deviation = 0.535 Å, and coplanar with each other, forming a dihedral angle of 5.4 (1°. Four weak intermolecular hydrogen bonds (C—H...O and C—H...N are observed in the structure, which join molecules into a network parallel to (101.

Polarization Studies for the eRHIC Electron Storage Ring

Energy Technology Data Exchange (ETDEWEB)

Gianfelice-Wendt, Eliana [Fermilab; Tepikian, S. [Brookhaven

2018-04-01

A hadron/lepton collider with polarized beams has been under consideration by the scientific community since some years, in the U.S. and Europe. Among the various proposals, those by JLAB and BNL with polarized electron and proton beams are currently under closer study in the U.S. Experimenters call for the simultaneous storage of electron bunches with both spin helicity. In the BNL based Ring-Ring design, electrons are stored at top energy in a ring to be accommodated in the existing RHIC tunnel. The transversely polarized electron beam is injected into the storage ring at variable energies, between 5 and 18 GeV. Polarization is brought into the longitudinal direction at the IP by a couple of spin rotators. In this paper results of first studies of the attainable beam polarization level and lifetime in the storage ring at 18 GeV are presented.

Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

Science.gov (United States)

Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

2015-01-02

A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fermilab Antiproton source, Recycler ring and Main Injector

Energy Technology Data Exchange (ETDEWEB)

Nagaitsev, Sergei [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2013-03-22

The antiproton source for a proton-antiproton collider at Fermilab was proposed in 1976 [1]. The proposal argued that the requisite luminosity (~10²⁹ cm^-2sec^-1) could be achieved with a facility that would produce and cool approximately 10¹¹ antiprotons per day. Funding for the Tevatron I project (to construct the Antiproton source) was initiated in 1981 and the Tevatron ring itself was completed, as a fixed target accelerator, in the summer of 1983 and the Antiproton Source was completed in 1985. At the end of its operations in 2011, the Fermilab antiproton production complex consisted of a sophisticated target system, three 8-GeV storage rings (namely the Debuncher, Accumulator and Recycler), 25 independent multi-GHz stochastic cooling systems, the world’s only relativistic electron cooling system and a team of technical experts equal to none. Sustained accumulation of antiprotons was possible at the rate of greater than 2.5×10¹¹ per hour. Record-size stacks of antiprotons in excess of 3×10¹² were accumulated in the Accumulator ring and 6×10¹² in the Recycler. In some special cases, the antiprotons were stored in rings for more than 50 days. Note, that over the years, some 10¹⁶ antiprotons were produced and accumulated at Fermilab, which is about 17 nanograms and more than 90% of the world’s total man-made quantity of nuclear antimatter. The accelerator complex at Fermilab supported a broad physics program including the Tevatron Collider Run II [2], neutrino experiments using 8 GeV and 120 GeV proton beams, as well as a test beam facility and other fixed target experiments using 120 GeV primary proton beams. The following sections provide a brief description of Fermilab accelerators as they operated at the end of the Collider Run II (2011).

Dual ring multilayer ionization chamber and theory-based correction technique for scanning proton therapy

International Nuclear Information System (INIS)

Takayanagi, Taisuke; Nishiuchi, Hideaki; Fujitaka, Shinichiro; Umezawa, Masumi; Nihongi, Hideaki; Tadokoro, Masahiro; Ito, Yuki; Nakashima, Chihiro; Matsuda, Koji; Sakae, Takeji; Terunuma, Toshiyuki

2016-01-01

Purpose: To develop a multilayer ionization chamber (MLIC) and a correction technique that suppresses differences between the MLIC and water phantom measurements in order to achieve fast and accurate depth dose measurements in pencil beam scanning proton therapy. Methods: The authors distinguish between a calibration procedure and an additional correction: 1—the calibration for variations in the air gap thickness and the electrometer gains is addressed without involving measurements in water; 2—the correction is addressed to suppress the difference between depth dose profiles in water and in the MLIC materials due to the nuclear interaction cross sections by a semiempirical model tuned by using measurements in water. In the correction technique, raw MLIC data are obtained for each energy layer and integrated after multiplying them by the correction factor because the correction factor depends on incident energy. The MLIC described here has been designed especially for pencil beam scanning proton therapy. This MLIC is called a dual ring multilayer ionization chamber (DRMLIC). The shape of the electrodes allows the DRMLIC to measure both the percentage depth dose (PDD) and integrated depth dose (IDD) because ionization electrons are collected from inner and outer air gaps independently. Results: IDDs for which the beam energies were 71.6, 120.6, 159, 180.6, and 221.4 MeV were measured and compared with water phantom results. Furthermore, the measured PDDs along the central axis of the proton field with a nominal field size of 10 × 10 cm 2 were compared. The spread out Bragg peak was 20 cm for fields with a range of 30.6 and 3 cm for fields with a range of 6.9 cm. The IDDs measured with the DRMLIC using the correction technique were consistent with those that of the water phantom; except for the beam energy of 71.6 MeV, all of the points satisfied the 1% dose/1 mm distance to agreement criterion of the gamma index. The 71.6 MeV depth dose profile showed slight

High luminosity polarized proton collisions at RHIC

International Nuclear Information System (INIS)

Roser, T.

2001-01-01

The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10 32 cm -2 s -1 . Such high luminosity and high energy polarized proton collisions will open up the possibility of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. After successful operation of RHIC with gold beams polarized protons from the AGS have been successfully injected into RHIC and accelerated using a full Siberian snakes built from four superconducting helical dipoles. A new high energy proton polarimeter was also successfully commissioned. Operation with two snakes per RHIC ring is planned for next year

Adsorbed States of phosphonate derivatives of N-heterocyclic aromatic compounds, imidazole, thiazole, and pyridine on colloidal silver: comparison with a silver electrode.

Science.gov (United States)

Podstawka, Edyta; Olszewski, Tomasz K; Boduszek, Bogdan; Proniewicz, Leonard M

2009-09-03

Here, we report a systematic surface-enhanced Raman spectroscopy (SERS) study of the structures of phosphonate derivatives of the N-heterocyclic aromatic compounds imidazole (ImMeP ([hydroxy(1H-imidazol-5-yl)methyl]phosphonic acid) and (ImMe)(2)P (bis[hydroxy-(1H-imidazol-4-yl)-methyl]phosphinic acid)), thiazole (BAThMeP (butylaminothiazol-2-yl-methyl)phosphonic acid) and BzAThMeP (benzylaminothiazol-2-yl-methyl)phosphonic acid)), and pyridine ((PyMe)(2)P (bis[(hydroxypyridin-3-yl-methyl)]phosphinic acid)) adsorbed on nanometer-sized colloidal particles. We compared these structures to those on a roughened silver electrode surface to determine the relationship between the adsorption strength and the geometry. For example, we showed that all of these biomolecules interact with the colloidal surface through aromatic rings. However, for BzAThMeP, a preferential interaction between the benzene ring and the colloidal silver surface is observed more so than that between the thiazole ring and this substrate. The PC(OH)C fragment does not take part in the adsorption process, and the phosphonate moiety of ImMeP and (ImMe)(2)P, being removed from the surface, only assists in this process.

Investigating the Effect of Pyridine Vapor Treatment on Perovskite Solar Cells - Oral Presentation

Energy Technology Data Exchange (ETDEWEB)

Ong, Alison J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-08-25

Perovskite photovoltaics have recently come to prominence as a viable alternative to crystalline silicon based solar cells. In an effort to create consistent and high-quality films, we studied the effect of various annealing conditions as well as the effect of pyridine vapor treatment on mixed halide methylammonium lead perovskite films. Of six conditions tested, we found that annealing at 100 degree Celsius for 90 minutes followed by 120 degree Celsius for 15 minutes resulted in the purest perovskite. Perovskite films made using that condition were treated with pyridine for various amounts of time, and the effects on perovskite microstructure were studied using x-ray diffraction, UV-Vis spectroscopy, and time-resolved photoluminescence lifetime analysis (TRPL). A previous study found that pyridine vapor caused perovskite films to have higher photoluminescence intensity and become more homogenous. In this study we found that the effects of pyridine are more complex: while films appeared to become more homogenous, a decrease in bulkphotoluminescence lifetime was observed. In addition, the perovskite bandgap appeared to decrease with increased pyridine treatment time. Finally, X-ray diffraction showed that pyridine vapor treatment increased the perovskite (110) peak intensity but also often gave rise to new unidentified peaks, suggesting the formation of a foreign species. It was observed that the intensity of this unknown species had an inverse correlation with the increase in perovskite peak intensity, and also seemed to be correlated with the decrease in TRPL lifetime.

Crystal structure of chlorido(2-{[2-(phenylcarbamothioylhydrazin-1-ylidene](pyridin-2-ylmethyl}pyridin-1-iumgold(I chloride sesquihydrate

Directory of Open Access Journals (Sweden)

Claudia C. Gatto

2015-09-01

Full Text Available The title complex, [AuCl(C18H16N5S]Cl·1.5H2O, may be considered as a gold(I compound with the corresponding metal site coordinated by a thiosemicarbazone ligand through the S atom. The ligand adopts an E conformation and the gold(I atom displays the expected linear geometry with a Cl atom also bonded to the metal ion [Cl—Au—S = 174.23 (5°]. One of the pyridyl rings is protonated, giving the gold complex an overall positive charge. Two solvent water molecules, one of which is located on a twofold rotation axis, and a non-coordinating chloride ion complete the structural assembly. The molecular structure is stabilized by intramolecular and intermolecular N—H...Cl, N—H...N, O—H...Cl and O—H...O hydrogen bonding.

Role of pendant proton relays and proton-coupled electron transfer on the hydrogen evolution reaction by nickel hangman porphyrins

Science.gov (United States)

Bediako, D. Kwabena; Solis, Brian H.; Dogutan, Dilek K.; Roubelakis, Manolis M.; Maher, Andrew G.; Lee, Chang Hoon; Chambers, Matthew B.; Hammes-Schiffer, Sharon; Nocera, Daniel G.

2014-01-01

The hangman motif provides mechanistic insights into the role of pendant proton relays in governing proton-coupled electron transfer (PCET) involved in the hydrogen evolution reaction (HER). We now show improved HER activity of Ni compared with Co hangman porphyrins. Cyclic voltammogram data and simulations, together with computational studies using density functional theory, implicate a shift in electrokinetic zone between Co and Ni hangman porphyrins due to a change in the PCET mechanism. Unlike the Co hangman porphyrin, the Ni hangman porphyrin does not require reduction to the formally metal(0) species before protonation by weak acids in acetonitrile. We conclude that protonation likely occurs at the Ni(I) state followed by reduction, in a stepwise proton transfer–electron transfer pathway. Spectroelectrochemical and computational studies reveal that upon reduction of the Ni(II) compound, the first electron is transferred to a metal-based orbital, whereas the second electron is transferred to a molecular orbital on the porphyrin ring. PMID:25298534

Manifestations of geometric phases in a proton electric-dipole-moment experiment in an all-electric storage ring

Science.gov (United States)

Silenko, Alexander J.

2017-12-01

We consider a proton electric-dipole-moment experiment in an all-electric storage ring when the spin is frozen and local longitudinal and vertical electric fields alternate. In this experiment, the geometric (Berry) phases are very important. Due to the these phases, the spin rotates about the radial axis. The corresponding systematic error is rather important while it can be canceled with clockwise and counterclockwise beams. The geometric phases also lead to the spin rotation about the radial axis. This effect can be canceled with clockwise and counterclockwise beams as well. The sign of the azimuthal component of the angular velocity of the spin precession depends on the starting point where the spin orientation is perfect. The radial component of this quantity keeps its value and sign for each starting point. When the longitudinal and vertical electric fields are joined in the same sections without any alternation, the systematic error due to the geometric phases does not appear but another systematic effect of the spin rotation about the azimuthal axis takes place. It has opposite signs for clockwise and counterclockwise beams.

Some aspects of radiation protection near high-energy proton accelerators

CERN Document Server

Tuyn, Jan Willem Nicolaas

1977-01-01

The CERN site near Geneva borders Satigny and Meyrin in Switzerland and Saint-Genis-Pouilly and Prevention in France. The 600 MeV proton synchrocyclotron (SC) has been in operation since 1957, the 28 GeV proton synchrotron (PS) since 1960, and the Intersecting Storage Rings (ISR) since 1971. A fourth large accelerator, the 400 GeV super proton synchrotron (SPS), will soon be in service. The internal and external radiation protection problems caused by these machines, together with the solutions, are reviewed in the light of experience. (5 refs).

Trihydroborates and dihydroboranes bearing a pentacoordinated phosphorus atom: double ring expansion to balance the coordination states

Energy Technology Data Exchange (ETDEWEB)

Kano, Naokazu; O' Brien, Nathan J. [Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan); Uematsu, Ryohei; Ramozzi, Romain; Morokuma, Keiji [Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyou-ku, Kyoto, 606-8103 (Japan)

2017-05-15

The first trihydroborate bearing a pentacoordinated phosphorus atom was synthesized as a new P-B bonded compound. Hydride abstraction of the trihydroborate gave an intermediary dihydroborane, which showed hydroboration reactivity and was trapped with pyridine whilst maintaining the P-B bond. The dihydroborane underwent a rearrangement, which involved a double ring expansion to compensate for the unbalanced coordination states of the phosphorus and boron atoms, to give a new fused bicyclic phosphine-boronate. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Trihydroborates and dihydroboranes bearing a pentacoordinated phosphorus atom: double ring expansion to balance the coordination states

International Nuclear Information System (INIS)

Kano, Naokazu; O'Brien, Nathan J.; Uematsu, Ryohei; Ramozzi, Romain; Morokuma, Keiji

2017-01-01

The first trihydroborate bearing a pentacoordinated phosphorus atom was synthesized as a new P-B bonded compound. Hydride abstraction of the trihydroborate gave an intermediary dihydroborane, which showed hydroboration reactivity and was trapped with pyridine whilst maintaining the P-B bond. The dihydroborane underwent a rearrangement, which involved a double ring expansion to compensate for the unbalanced coordination states of the phosphorus and boron atoms, to give a new fused bicyclic phosphine-boronate. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Research on degradation of vacuum O-rings under gamma radiation

CERN Document Server

Ino, H; Saitô, Y; Kubo, T; Kinsho, M

2003-01-01

The high-intensity proton accelerator being constructed by JAERI and KEK will generates greater beam power than conventional accelerators. The radiation emission due to beam losses will therefore increase. Since vacuum O-rings installed in the accelerator will be degraded badly by the radiation, there is need to find an O-ring that has more resistant to radiation. To find an O-ring that has better radiation resistant than that of the fluororubber used for conventional accelerators in general, some O-rings which are expected to have enough resistant to the radiation were irradiated, and estimated a degradation by measurement of outgassing rate, hardness, permeation time of helium gas, and an outward observation. Most of the O-rings were irradiated in an oxygen free atmosphere and in the air. The irradiations were carried out at room temperature in Co-60 gamma irradiation facility until a dose of 1 MGy was reached. The radiation resistance of PURE-RUBBER O-ring showed somewhat better than that of the fluororubb...

Bunch coalescing in the Fermilab Main Ring

International Nuclear Information System (INIS)

Wildman, D.; Martin, P.; Meisner, K.; Miller, H.W.

1987-01-01

A new RF system has been installed in the Fermilab Main Ring to coalesce up to 13 individual bunches of protons or antiprotons into a single high-intensity bunch. The coalescing process consists of adiabatically reducing the h=1113 Main Ring RF voltage from 1 MV to less than 1 kV, capturing the debunched beam in a linearized h=53 and h=106 bucket, rotating for a quarter of a synchrotron oscillation period, and then recapturing the beam in a single h=1113 bucket. The new system is described and the results of recent coalescing experiments are compared with computer-generated particle tracking simulations

Constraining the proton structure at ATLAS

CERN Document Server

Tricoli, Alessandro; Viehhauser, Georg

Particle physics is at a pivotal moment: the origin of mass and new physics scenarios beyond the Standard Model or particle physics could be unveiled in the coming year. In 2007 the most powerful particl e accelerator, the Large Hadron Coolider (LHC), will start colliding proton beams reaching the ihghest energy and luminosity ever in collider particle physics. The ATLAS detector is one of two general pu rpose detectors placed along the collider ring to fully exploit the LHC potential. The theoretical uncertainties on most of the LHC physics progream are dominated by the proton structure uncertaintiy. This thesis demonstrates that $W^{\\pm}$ boson productionis an ideal process to constr ain the proton strcuture uncertainty. The rapidity distributions of electrons and positrons originating respectively from the $W^-$ and $W^+$ decays have been analysed. The results show that the current uncertainty on the gluon content of the proton can be reduced by a very significant amount if the total systematic uncertaint...

3-Amino-thieno[2,3-b]pyridines as microtubule-destabilising agents: Molecular modelling and biological evaluation in the sea urchin embryo and human cancer cells.

Science.gov (United States)

Eurtivong, Chatchakorn; Semenov, Victor; Semenova, Marina; Konyushkin, Leonid; Atamanenko, Olga; Reynisson, Jóhannes; Kiselyov, Alex

2017-01-15

A series of 3-amino-thieno[2,3-b]pyridines was prepared and tested in a phenotypic sea urchin embryo assay to identify potent and specific molecules that affect tubulin dynamics. The most active compounds featured a tricyclic core ring system with a fused cycloheptyl or cyclohexyl substituent and unsubstituted or alkyl-substituted phenyl moiety tethered via a carboxamide. Low nano-molar potency was observed in the sea urchin embryos for the most active compounds (1-5) suggestive of a microtubule-destabilising effect. The molecular modelling studies indicated that the tubulin colchicine site is inhibited, which often leads to microtubule-destabilisation in line with the sea urchin embryo results. Finally, the identified hits displayed a robust growth inhibition (GI 50 of 50-250nM) of multidrug-resistant melanoma MDA-MB-435 and breast MDA-MB-468 human cancer cell lines. This work demonstrates that for the thieno[2,3-b]pyridines the most effective mechanism of action is microtubule-destabilisation initiated by binding to the colchicine pocket. Copyright © 2016 Elsevier Ltd. All rights reserved.

Present status of device controls and hardware interfaces for the RCNP ring cyclotron

International Nuclear Information System (INIS)

Yamazaki, T.; Tamura, K.; Hosono, K.

1994-01-01

Since the first proton beam from the injector AVF cyclotron was injected to the ring cyclotron in 1991, the computer control system has been used for the beam acceleration of the ring cyclotron. Some device control modules have been updated, and computer configuration has been changed in 1992. Total control system performs basic facilities almost satisfactory under actual cyclotron operation. (author)

Protonated serotonin: Geometry, electronic structures and photophysical properties

Science.gov (United States)

Omidyan, Reza; Amanollahi, Zohreh; Azimi, Gholamhassan

2017-07-01

The geometry and electronic structures of protonated serotonin have been investigated by the aim of MP2 and CC2 methods. The relative stabilities, transition energies and geometry of sixteen different protonated isomers of serotonin have been presented. It has been predicted that protonation does not exhibit essential alteration on the S1 ← S0 electronic transition energy of serotonin. Instead, more complicated photophysical nature in respect to its neutral analogue is suggested for protonated system owing to radiative and non-radiative deactivation pathways. In addition to hydrogen detachment (HD), hydrogen/proton transfer (H/PT) processes from ammonium to indole ring along the NH+⋯ π hydrogen bond have been predicted as the most important photophysical consequences of SERH+ at S1 excited state. The PT processes is suggested to be responsible for fluorescence of SERH+ while the HD driving coordinate is proposed for elucidation of its nonradiative deactivation mechanism.

Crucial role of molecular planarity on the second order nonlinear optical property of pyridine based chalcone single crystals

Science.gov (United States)

Menezes, Anthoni Praveen; Jayarama, A.; Ng, Seik Weng

2015-05-01

An efficient nonlinear optical material 2E-3-(4-bromophenyl)-1-(pyridin-3-yl) prop-2-en-1-one (BPP) was synthesized and single crystals were grown using slow evaporation solution growth technique at room temperature. Grown crystal had prismatic morphology and its structure was confirmed by various spectroscopic studies, elemental analysis, and single crystal X-ray diffraction (XRD) technique. The single crystal XRD of the crystal showed that BPP crystallizes in monoclinic system with noncentrosymmetric space group P21 and the cell parameters are a = 5.6428(7) Å, b = 3.8637(6) Å, c = 26.411(2) Å, β = 97.568(11) deg and v = 575.82(12) Å3. The UV-Visible spectrum reveals that the crystal is optically transparent and has high optical energy band gap of 3.1 eV. The powder second harmonic generation efficiency (SHG) of BPP is 6.8 times that of KDP. From thermal analysis it is found that the crystal melts at 139 °C and decomposes at 264 °C. High optical transparency down to blue region, higher powder SHG efficiency and better thermal stability than that of urea makes this chalcone derivative a promising candidate for SHG applications. Furthermore, effect of molecular planarity on SHG efficiency and role of pyridine ring adjacent to carbonyl group in forming noncentrosymmetric crystal systems of chalcone family is also discussed.

Tris(2,2′-bipyridine-κ2 N,N′)cobalt(III) bis­[bis­(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)cobaltate(III)] perchlorate dimethyl­formamide hemisolvate 1.3-hydrate

Science.gov (United States)

Golenya, Irina A.; Boyko, Alexander N.; Kotova, Natalia V.; Haukka, Matti; Iskenderov, Turganbay S.

2012-01-01

In the title compound, [Co(C10H8N2)3][Co(C7H3NO4)2]2(ClO4)·0.5C3H7NO·1.3H2O, the CoIII atom in the complex cation is pseudoocta­hedrally coordinated by six N atoms of three chelating bipyridine ligands. The CoIII atom in the complex anion is coordinated by two pyridine N atoms and four carboxyl­ate O atoms of two doubly deprotonated pyridine-2,6-dicarboxyl­ate ligands in a distorted octa­hedral geometry. One dimethyl­formamide solvent mol­ecule and two water mol­ecules are half-occupied and one water mol­ecule is 0.3-occupied. O—H⋯O hydrogen bonds link the water mol­ecules, the perchlorate anions and the complex anions. π–π inter­actions between the pyridine rings of the complex anions are also observed [centroid–centroid distance = 3.804 (3) Å]. PMID:23125573

A proton beam delivery system for conformal therapy and intensity modulated therapy

International Nuclear Information System (INIS)

Yu Qingchang

2001-01-01

A scattering proton beam delivery system for conformal therapy and intensity modulated therapy is described. The beam is laterally spread out by a dual-ring double scattering system and collimated by a program-controlled multileaf collimator and patient specific fixed collimators. The proton range is adjusted and modulated by a program controlled binary filter and ridge filters

Production spectra of π+-, K+-, p+- at large angles in proton-proton collisions in the CERN intersecting storage rings

International Nuclear Information System (INIS)

Alper, B.; Boeggild, H.; Booth, P.; Bulos, F.; Carroll, L.J.; Damgaard, G.; Von Dardel, G.; Duff, B.; Hansen, K.H.; Heymann, F.; Jackson, J.N.; Jarlskog, G.; Joensson, L.; Klovning, A.; Leistam, L.; Lillethun, E.; Lohse, E.; Lynch, G.; Manning, G.; Potter, K.; Prentice, M.; Sharp, P.; Sharrock, S.; Oelgaard-Nielsen, S.; Quarrie, D.; Weiss, J.M.

1975-01-01

Results are given on the inclusive production of charged pions, kaons, and nucleons, in proton-proton collisions at c.m. energies from √s=23 to 63 GeV at large angles and for the transverse momentum range 0.1 < psub(T) < 4.8 GeV/c. The dependence of the production spectra on the collision energy √s, the transverse momentum psub(T), and the longitudinal rapidity is discussed. (Auth.)

Quantification of Representative Ciguatoxins in the Pacific Using Quantitative Nuclear Magnetic Resonance Spectroscopy

Directory of Open Access Journals (Sweden)

Tsuyoshi Kato

2017-10-01

Full Text Available The absolute quantification of five toxins involved in ciguatera fish poisoning (CFP in the Pacific was carried out by quantitative 1H-NMR. The targeted toxins were ciguatoxin-1B (CTX1B, 52-epi-54-deoxyciguatoxin-1B (epideoxyCTX1B, ciguatoxin-3C (CTX3C, 51-hydroxyciguatoxin-3C (51OHCTX3C, and ciguatoxin-4A (CTX4A. We first calibrated the residual protons of pyridine-d5 using certified reference material, 1,4-BTMSB-d4, prepared the toxin solutions with the calibrated pyridin-d5, measured the 1H-NMR spectra, and quantified the toxin using the calibrated residual protons as the internal standard. The absolute quantification was carried out by comparing the signal intensities between the selected protons of the target toxin and the residual protons of the calibrated pyridine-d5. The proton signals residing on the ciguatoxins (CTXs to be used for quantification were carefully selected for those that were well separated from adjacent signals including impurities and that exhibited an effective intensity. To quantify CTX1B and its congeners, the olefin protons in the side chain were judged appropriate for use. The quantification was achievable with nano-molar solutions. The probable errors for uncertainty, calculated on respective toxins, ranged between 3% and 16%. The contamination of the precious toxins with nonvolatile internal standards was thus avoided. After the evaporation of pyridine-d5, the calibrated CTXs were ready for use as the reference standard in the quantitative analysis of ciguatoxins by LC/MS.

Bunch coalescing and bunch rotation in the Fermilab Main Ring: Operational experience and comparison with simulations

International Nuclear Information System (INIS)

Martin, P.S.; Wildman, D.W.

1988-01-01

The Fermilab Tevatron I proton-antiproton collider project requires that the Fermilab Main Ring produce intense bunches of protons and antiprotons for injection into the Tevatron. The process of coalescing a small number of harmonic number h=1113 bunches into a single bunch by bunch-rotating in a lower harmonic rf system is described.The Main Ring is also required to extract onto the antiproton production target bunches with as narrow a time spread as possible. This operation is also discussed. The operation of the bunch coalescing and bunch rotation are compared with simulations using the computer program ESME. 2 refs., 8 figs

Preparation of novel pyrrolo [2,3-b]pyridine derivatives via a new concise synthetic approach

Energy Technology Data Exchange (ETDEWEB)

Guo, Na; Jia, Haiyong; You, Xing; Jiang, Du; Lu, Kui; Yu, Peng [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, Tianjin University of Science and Technology, Tianjin (China)

2015-04-15

The pyrrolo[2,3-b]pyridine core structure, a bioisostere of quinolones, is found in several molecules that possess important biological activity. We describe here a new, concise, three-step synthesis of pyrrolo[2,3-b]pyridines starting from L-alanine. A series of 4,7-dihydro-4-oxo-1H-pyrrolo[2,3-b]pyridine-5-carboxylic acid derivatives, which have not been previously reported, were synthesized using this approach.

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

Science.gov (United States)

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

2014-06-14

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

Phosphorus, sulfur and pyridine

OpenAIRE

Schönberger, Stefanie

2013-01-01

The synthesis of distinct neutral or anionic P,S compounds in solution provides a great challenge for chemists. Due to the similarity in the energies of the P–P, P–S and S–S bonds nearly solely a mixture of compounds with different composition and charge is obtained. Our interest focuses on the system consisting of phosphorus, sulfur and pyridine, with the aim of a greater selectivity of P,S compounds in solution. The combination of these three components offers the opportunity...

An outline of research facilities of high intensity proton accelerator

International Nuclear Information System (INIS)

Tanaka, Shun-ichi

1995-01-01

A plan called PROTON ENGINEERING CENTER has been proposed in JAERI. The center is a complex composed of research facilities and a beam shape and storage ring based on a proton linac with an energy of 1.5 GeV and an average current of 10 mA. The research facilities planned are OMEGA·Nuclear Energy Development Facility, Neutron Facility for Material Irradiation, Nuclear Data Experiment Facility, Neutron Factory, Meson Factory, spallation Radioisotope Beam Facility, and Medium Energy Experiment Facility, where high intensity proton beam and secondary particle beams such as neutrons, π-mesons, muons, and unstable isotopes originated from the protons are available for promoting the innovative research of nuclear energy and basic science and technology. (author)

N-{4-[4-(4-Fluorophenyl-1-(2-methoxyethyl-2-methylsulfanyl-1H-imidazol-5-yl]-2-pyridyl}-2-methyl-3-phenylpropionamide

Directory of Open Access Journals (Sweden)

Stefan Laufer

2009-12-01

Full Text Available In the crystal structure of the title compound, C28H29FN4O2S, the imidazole ring makes dihedral angles of 11.85 (7, 73.33 (7 and 22.83 (8° with the 4-fluorophenyl, pyridine and phenyl rings, respectively. The 4-fluorophenyl ring makes dihedral angles of 77.91 (7 and 26.93 (8° with the pyridine and phenyl rings, respectively. The phenyl and pyridine rings are nearly perpendicular, making a dihedral angle of 86.47 (9°. The crystal packing shows an intermolecular N—H...O hydrogen-bonding interaction between the N—H and carbonyl groups of the amide functions.

Regulation of Ca2+ release from mitochondria by the oxidation-reduction state of pyridine nucleotides

Science.gov (United States)

Lehninger, Albert L.; Vercesi, Anibal; Bababunmi, Enitan A.

1978-01-01

Mitochondria from normal rat liver and heart, and also Ehrlich tumor cells, respiring on succinate as energy source in the presence of rotenone (to prevent net electron flow to oxygen from the endogenous pyridine nucleotides), rapidly take up Ca2+ and retain it so long as the pyridine nucleotides are kept in the reduced state. When acetoacetate is added to bring the pyridine nucleotides into a more oxidized state, Ca2+ is released to the medium. A subsequent addition of a reductant of the pyridine nucleotides such as β-hydroxybutyrate, glutamate, or isocitrate causes reuptake of the released Ca2+. Successive cycles of Ca2+ release and uptake can be induced by shifting the redox state of the pyridine nucleotides to more oxidized and more reduced states, respectively. Similar observations were made when succinate oxidation was replaced as energy source by ascorbate oxidation or by the hydrolysis of ATP. These and other observations form the basis of a hypothesis for feedback regulation of Ca2+-dependent substrate- or energy-mobilizing enzymatic reactions by the uptake or release of mitochondrial Ca2+, mediated by the cytosolic phosphate potential and the ATP-dependent reduction of mitochondrial pyridine nucleotides by reversal of electron transport. Images PMID:25436

Search for long-lived heavy charged particles using a ring imaging Cherenkov technique at LHCb

NARCIS (Netherlands)

Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A., Jr.; Amato, S.; Amerio, S.; Amhis, Y.; Everse, LA; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J.E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M-O.; Van Beuzekom, Martin; Bien, A.; Bifani, S.; Bird, T.D.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. H. Campora; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph; Chefdeville, M.; Chen, S.; Cheung, S-F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; CruzTorres, M.; Cunliffe, S.; Currie, C.R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; de Miranda, J. M.; Paula, L.E.; da-Silva, W.S.; De Simone, P.; Dean, C-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; ElRifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T. M.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, Mark; Fontanelli, F.; Forty, R.; De Aguiar Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Torreira, A. Gallas; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Tico, J. Garra; Garrido, L.; Gascon, D.; Carvalho-Gaspar, M.; Gauld, Rhorry; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T. J.; Ghez, Ph; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.Q.; Gotti, C.; Gandara, M. Grabalosa; Diaz, R. Graciani; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, H.M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D. E.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M. H.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.M.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G. D.; Lai, A.; Lambert, D.M.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T. E.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, S.C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martinelli-Boneschi, F.; Santos, D. Martinez; Martinez-Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; McSkelly, B.; Meadows, B. T.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mueller, J.; Mueller, Karl; Mueller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, E.A.; Owen, R.P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L.L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, D.A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Olloqui, E. Picatoste; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, M. E.; Price, J.D.; Prisciandaro, J.; Pritchard, C.A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, Y.W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M.; dos Reis, A. C.; Ricciardi, S.; Richards, Jennifer S; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, L.E.T.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, van Hapere; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, R. H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; de Souza, D.K.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson-Moore, P.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M. N.; Todd, Jim; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, N.T.M.T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, M.J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, John; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M.P.; Williams, M.; Wilson, James F; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.J.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

2015-01-01

A search is performed for heavy long-lived charged particles using 3.0 fb(-1) of proton-proton collisions collected at √s = 7 and 8 TeV with the LHCb detector. The search is mainly based on the response of the ring imaging Cherenkov detectors to distinguish the heavy, slow-moving particles from

The beam slow extraction from a magnetic ring of Moscow meson facility

International Nuclear Information System (INIS)

Gusev, O.A.; Malitsky, N.D.; Severgin, Yu.P.; Titov, V.A.; Shukeilo, I.A.; Aseev, V.N.; Grachev, M.I.; Lobashev, V.M.; Ostroumov, P.N.; Ponomaryov, O.V.

1990-01-01

The beam slow extraction from the circular accelerators or stretcher rings is generally realized by the resonant excitation of betratron oscillations. A precise betatron frequency control is proved to be quite necessary for high-efficient slow ejection. The Coulomb field turns out to have a significant influence upon the slow extraction from the high-current medium energy proton storage rings. It prevents resonant excitation at a reasonable rate and reduces the ejection efficiency. The proton storage ring of Moscow meson facility is an example of a stretcher with a noticeable beam space charge. The detailed investigation of the resonant ejection, having been performed for our stretcher, resulted in the conclusion that extracted beam average current should be limited by the value of 50 mA, which is only 10% of the linac design current. The search for the alternative version to the resonant ejection made us to analyze in details and to develop an old-fashioned method, based on the radial betatron oscillation excitation while the beam is being gradually shifted onto the thin target. (author) 5 refs., 4 figs

Crystal structures of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper and chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper

Energy Technology Data Exchange (ETDEWEB)

Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paholnitcaia, A. Yu. [State University of Moldova (Moldova, Republic of); Petrenko, P. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [State University of Moldova (Moldova, Republic of); Poirier, D. [Centre Hospitalier Universitaire de Quebec (Canada); Gulea, A. P. [State University of Moldova (Moldova, Republic of)

2015-01-15

Two crystal modifications of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper (I and II) and two modifications of chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper (III and IV) have been synthesized and studied by X-ray diffraction. In structures I and II, the copper atoms coordinate a monodeprotonated molecule of the organic ligand, nitrate ions, and a water molecule. In crystals of I, the complexes are monomeric, whereas complexes II are linked via nitrate ions to form polymeric chains. In both structures the coordination polyhedron of the copper atom can be described as a distorted tetragonal bipyramid—(4 + 1 + 1) in I and (4 + 2) in II. These coordination polyherdra have different compositions. In structures III and IV, the metal atoms coordinate a monodeprotonated (2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazole molecule and chloride ions. In III the complex-forming ion has square-planar coordination geometry, whereas structure IV consists of centrosymmetric dimers with two bridging chlorine atoms. It was found that nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper possesses antitumor activity.

Molecular architecture of the N-type ATPase rotor ring from Burkholderia pseudomallei.

Science.gov (United States)

Schulz, Sarah; Wilkes, Martin; Mills, Deryck J; Kühlbrandt, Werner; Meier, Thomas

2017-04-01

The genome of the highly infectious bacterium Burkholderia pseudomallei harbors an atp operon that encodes an N-type rotary ATPase, in addition to an operon for a regular F-type rotary ATPase. The molecular architecture of N-type ATPases is unknown and their biochemical properties and cellular functions are largely unexplored. We studied the B. pseudomallei N 1 N o -type ATPase and investigated the structure and ion specificity of its membrane-embedded c-ring rotor by single-particle electron cryo-microscopy. Of several amphiphilic compounds tested for solubilizing the complex, the choice of the low-density, low-CMC detergent LDAO was optimal in terms of map quality and resolution. The cryoEM map of the c-ring at 6.1 Å resolution reveals a heptadecameric oligomer with a molecular mass of ~141 kDa. Biochemical measurements indicate that the c 17 ring is H + specific, demonstrating that the ATPase is proton-coupled. The c 17 ring stoichiometry results in a very high ion-to-ATP ratio of 5.7. We propose that this N-ATPase is a highly efficient proton pump that helps these melioidosis-causing bacteria to survive in the hostile, acidic environment of phagosomes. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Large protonation-gated photochromism of an OPE-embedded difurylperfluorocyclopentene

KAUST Repository

Wolf, Jannic Sebastian

2015-01-01

A recently reported protolytic gating effect on the ring closing reaction of an oligo(phenylene ethynylene) (OPE) embedded difurylperfluorocyclopentene (S) with a dimethylaminophenyl chain link in each of the side arms, was quantitatively analyzed in detail. The reaction system (So, SoH+, SoH2 2+, Sc, ScH+, ScH2 2+) comprising three protolytic forms in both open and closed configuration, is characterized by four protolytic equilibrium constants and six photochemical quantum yields of ring closing and ring opening. The absorption spectra, conductivity, and effective photochemical quantum yields were measured in acetonitrile as functions of solvent acidity varied by addition of trifluoroacetic acid and triethylamine and characterized by an effective pHnon-aq. Based on the derivation of a rigorous method for assessing the individual quantum yields of ring closure and ring opening of the six species, it was shown that it is specifically the second protonation step that is responsible for a more than 10-fold increase in the quantum yield of ring closure.

Antiproton acceleration in the Fermilab Main Ring and Tevatron

International Nuclear Information System (INIS)

Martin, P.; Dinkel, J.; Ducar, R.

1987-01-01

The operation of the Fermilab Main Ring and Tevatron rf systems for colliding beams physics is discussed. The changes in the rf feedback system required for acceleration of antiprotons, and the methods for achieving proper transfer of both protons and antiprotons are described. Data on acceleration and transfer efficiencies are presented

N,N′-(Ethane-1,2-diyldi-o-phenylenebis(pyridine-2-carboxamide

Directory of Open Access Journals (Sweden)

Shuranjan Sarkar

2011-11-01

Full Text Available The title molecule, C26H22N4O2, is centrosymmetric and adopts an anti conformation. Two intramolecular hydrogen bonds, viz. amide–pyridine N—H...N and phenyl–amide C—H...O, stabilize the trans conformation of the (pyridine-2-carboxamidophenyl group about the amide plane. In the crystal, the presence of weak intermolecular C—H...O hydrogen bonds results in the formation of a three-dimensional network.

Pyridine-induced Dimensionality Change in Hybrid Perovskite Nanocrystals

KAUST Repository

Ahmed, Ghada H.

2017-05-02

Engineering the surface energy through careful manipulation of the surface chemistry is a convenient approach to control quantum confinement and structure dimensionality during nanocrystal growth. Here, we demonstrate that the introduction of pyridine during the synthesis of methylammonium lead bromide (MAPbBr) perovskite nanocrystals can transform three-dimensional (3D) cubes into two-dimensional (2D) nanostructures. Density functional theory (DFT) calculations show that pyridine preferentially binds to Pb atoms terminating the surface, driving the selective 2D growth of the nanostructures. These 2D nanostructures exhibit strong quantum confinement effects, high photoluminescence quantum yields in the visible spectral range, and efficient charge transfer to molecular acceptors. These qualities indicate the suitability of the synthesized 2D nanostructures for a wide range of optoelectronic applications.

NHC Versus Pyridine: How “Teeth” Change the Redox Behavior of Iron(II) Complexes

KAUST Repository

Weiss, Daniel T.; Anneser, Markus R.; Haslinger, Stefan; Pö thig, Alexander; Cokoja, Mirza; Basset, Jean-Marie; Kü hn, Fritz E.

2015-01-01

A series of octahedral iron(II) complexes with tetradentate NHC/pyridine hybrid ligands containing up to three pyridyl units was designed to study the influence of NHC and pyridine donors on the electronic structure of the metal center. Structural

Spin dynamics at level crossing in molecular AF rings probed by NMR

International Nuclear Information System (INIS)

Lascialfari, A.; Borsa, F.; Julien, M.-H.; Micotti, E.; Furukawa, Y.; Jang, Z.H.; Cornia, A.; Gatteschi, D.; Horvatic, M.; Van Slageren, J.

2004-01-01

The low-temperature spin dynamics in molecular rings with a finite number (N≤10) of magnetic ions was studied by means of 1 H NMR. When an external magnetic field (B) induces a crossing between energy levels, peaks are observed in the spin-lattice relaxation rate of protons, 1/T 1 (B), at constant temperature. We discuss similarities and differences in the data from three different rings: Fe10, Fe6:Li and Cr8

On the formation of niacin (vitamin B3) and pyridine carboxylic acids in interstellar model ices

Energy Technology Data Exchange (ETDEWEB)

McMurtry, Brandon M.; Turner, Andrew M.; Saito, Sean E.J.; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States); Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States)

2016-06-15

The formation of pyridine carboxylic acids in interstellar ice grains was simulated by electron exposures of binary pyridine (C{sub 5}H{sub 5}N)-carbon dioxide (CO{sub 2}) ice mixtures at 10 K under contamination-free ultrahigh vacuum conditions. Chemical processing of the pristine ice and subsequent warm-up phase was monitored on line and in situ via Fourier transform infrared spectroscopy to probe for the formation of new radiation induced species. In the infrared spectra of the irradiated ice, bands assigned to nicotinic acid (niacin; vitamin B3; m-C{sub 5}H{sub 4}NCOOH) along with 2,3-, 2,5-, 3,4-, and 3,5-pyridine dicarboxylic acid (C{sub 5}H{sub 3}N(COOH){sub 2}) were unambiguously identified along with the hydroxycarbonyl (HOCO) radical. Our study suggests that the reactive pathway responsible for pyridine carboxylic acids formation involves a HOCO intermediate, which forms through the reaction of suprathermal hydrogen ejected from pyridine with carbon dioxide. The newly formed pyridinyl radical may then undergo radical–radical recombination with a hydroxycarbonyl radical to form a pyridine carboxylic acid.

Polarizing a stored proton beam by spin flip?

International Nuclear Information System (INIS)

Oellers, D.; Barion, L.; Barsov, S.; Bechstedt, U.; Benati, P.; Bertelli, S.; Chiladze, D.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P.F.; Dietrich, J.; Dolfus, N.; Dymov, S.; Engels, R.; Erven, W.; Garishvili, A.; Gebel, R.; Goslawski, P.

2009-01-01

We discuss polarizing a proton beam in a storage ring, either by selective removal or by spin flip of the stored ions. Prompted by recent, conflicting calculations, we have carried out a measurement of the spin-flip cross section in low-energy electron-proton scattering. The experiment uses the cooling electron beam at COSY as an electron target. The measured cross sections are too small for making spin flip a viable tool in polarizing a stored beam. This invalidates a recent proposal to use co-moving polarized positrons to polarize a stored antiproton beam.

Elucidation of the substitution pattern of 9,10-anthraquinones through the chemical shifts of peri-hydroxyl protons

DEFF Research Database (Denmark)

Schripsema, Jan; Danigno, Denise

1996-01-01

In 9,10-anthraquinones the chemical shift of a peri-hydroxyl proton is affected by the substituents in the other benzenoid ring. These effects are additive. They are useful for the determination of substitution patterns and have been used to revise the structures of six previously reported...... anthraquinones containing methoxyl, hydroxyl, methylenedioxy and beta-methyl substituents. Because the chemical shifts of the other protons are hardly affected by substitutions in the other ring, the characteristic chemical shifts for a wide variety of substitution patterns could be derived....

Cherenkov rings from aerogel detected by four large-area hybrid photodiodes

International Nuclear Information System (INIS)

Bellunato, T.; Braem, A.; Buzykaev, A.R.; Calvi, M.; Chesi, E.; Danilyuk, A.F.; Easo, S.; Jolly, S.; Joram, C.; Kravchenko, E.A.; Liko, D.; Matteuzzi, C.; Musy, M.; Negri, P.; Neufeld, N.; Onuchin, A.P.; Seguinot, J.; Wotton, S.

2003-01-01

We report on the results obtained using thick samples of silica aerogel as radiators for a Ring Imaging Cherenkov counter. Four large-diameter hybrid photodiodes with 2048 channels have been used as photon detectors. Pions and protons with momenta ranging from 6 to 10 GeV/c were separated and identified. The number of photoelectrons and the radius of the Cherenkov rings together with the Cherenkov angle resolution were measured. A comparison with a simulation program based on GEANT4 is discussed

Polymer Soft-Landing Isolation of Acetylene on Polystyrene and Poly(vinylpyridine): A Novel Approach to Probing Hydrogen Bonding in Polymers.

Science.gov (United States)

Li, Yike; Samet, Cindy

2015-09-17

Hydrogen-bonded complexes of acetylene (Ac) with the polymers polystyrene (PS), poly(4-vinylpyridine) (P4VP), and poly(2-vinylpyridine) (P2VP) have been characterized for the first time at 16 K in a "polymer soft-landing isolation" experiment which is being pioneered in our research laboratory. In particular, changes in vibrational modes of Ac provide ample evidence for hydrogen-bonded complexes between Ac and the phenyl groups of PS or the pyridyl groups of P4VP and P2VP. With PS, the proton on the top Ac molecule of the classic T-shaped Ac dimer interacts with the π cloud of the benzene (Bz) ring to form a C-H---π interaction, while the π cloud of the lower Ac forms a second C-H---π interaction with a proton on the Bz ring. An analogous (ring)1-(Ac)2 double interaction occurs between an Ac dimer and the pyridine (Pyr) rings on both P2VP and P4VP, yielding a C-H---N and C-H---π interaction. With P4VP and P2VP a second bridged (ring)2-(Ac)2 product is formed, with the Ac dimer forming nearly collinear C-H---N hydrogen bonds to adjacent Pyr rings. On P2VP this bridged product is the only one after extensive annealing. These complexes in which Ac acts as both proton donor and acceptor have not previously been observed in conventional matrix isolation experiments. This study is the second from our laboratory employing this method, which represents a slight modification of the traditional matrix isolation technique.

trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

Science.gov (United States)

Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

2009-01-01

In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

Intermolecular interactions between σ- and π-holes of bromopentafluorobenzene and pyridine: computational and experimental investigations.

Science.gov (United States)

Yang, Fang-Ling; Yang, Xing; Wu, Rui-Zhi; Yan, Chao-Xian; Yang, Fan; Ye, Weichun; Zhang, Liang-Wei; Zhou, Pan-Pan

2018-04-25

The characters of σ- and π-holes of bromopentafluorobenzene (C6F5Br) enable it to interact with an electron-rich atom or group like pyridine which possesses an electron lone-pair N atom and a π ring. Theoretical studies of intermolecular interactions between C6F5Br and C5H5N have been carried out at the M06-2X/aug-cc-pVDZ level without and with the counterpoise method, together with single point calculations at M06-2X/TZVP, wB97-XD/aug-cc-pVDZ and CCSD(T)/aug-cc-pVDZ levels. The σ- and π-holes of C6F5Br exhibiting positive electrostatic potentials make these sites favorably interact with the N atom and the π ring of C5H5N with negative electrostatic potentials, leading to five different dimers connected by a σ-holen bond, a σ-holeπ bond or a π-holeπ bond. Their geometrical structures, characteristics, nature and spectroscopy behaviors were systematically investigated. EDA analyses reveal that the driving forces in these dimers are different. NCI, QTAIM and NBO analyses confirm the existence of intermolecular interactions formed via σ- and π-holes of C6F5Br and the N atom and the π ring of C5H5N. The experimental IR and Raman spectra gave us important information about the formation of molecular complexes between C6F5Br and C5H5N. We expect that the results could provide valuable insights into the investigation of intermolecular interactions involving σ- and π-holes.

Reuse Recycler: High Intensity Proton Stacking at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Adamson, P. [Fermilab

2016-07-17

After a successful career as an antiproton storage and cooling ring, Recycler has been converted to a high intensity proton stacker for the Main Injector. We discuss the commissioning and operation of the Recycler in this new role, and the progress towards the 700 kW design goal.

Proton flux under radiation belts: near-equatorial zone

International Nuclear Information System (INIS)

Grigoryan, O.R.; Panasyuk, M.I.; Petrov, A.N.; Kudela, K.

2005-01-01

In this work the features of low-energy proton flux increases in near-equatorial region (McIlvein parameter L th the proton flux (with energy from tens keV up to several MeV) increases are registering regularly. However modern proton flux models (for example AP8 model) works at L>1.15 only and does not take into account near-equatorial protons. These fluxes are not too big, but the investigation of this phenomenon is important in scope of atmosphere-ionosphere connections and mechanisms of particles transport in magnetosphere. In according to double charge-exchange model the proton flux in near-equatorial region does not depend on geomagnetic local time (MLT) and longitude. However the Azur satellite data and Kosmos-484, MIR station and Active satellite data revealed the proton flux dependence on longitude. The other feature of near-equatorial proton flux is the dependence on geomagnetic local time revealed in the Sampex satellite experiment and other experiments listed above. In this work the dependences on MLT and longitude are investigated using the Active satellite (30-500 keV) and Sampex satellite (>800 keV). This data confirms that main sources of near-equatorial protons are radiation belts and ring current. The other result is that near-equatorial protons are quasi-trapped. The empirical proton flux dependences on L, B at near-equatorial longitudes are presented. (author)

Link between EMIC waves in a plasmaspheric plume and a detached sub-auroral proton arc with observations of Cluster and IMAGE satellites

Science.gov (United States)

Yuan, Zhigang; Deng, Xiaohua; Lin, Xi; Pang, Ye; Zhou, Meng; Décréau, P. M. E.; Trotignon, J. G.; Lucek, E.; Frey, H. U.; Wang, Jingfang

2010-04-01

In this paper, we report observations from a Cluster satellite showing that ULF wave occurred in the outer boundary of a plasmaspheric plume on September 4, 2005. The band of observed ULF waves is between the He+ ion gyrofrequency and O+ ion gyrofrequency at the equatorial plane, implying that those ULF waves can be identified as EMIC waves generated by ring current ions in the equatorial plane and strongly affected by rich cold He+ ions in plasmaspheric plumes. During the interval of observed EMIC waves, the footprint of Cluster SC3 lies in a subauroral proton arc observed by the IMAGE FUV instrument, demonstrating that the subauroral proton arc was caused by energetic ring current protons scattered into the loss cone under the Ring Current (RC)-EMIC interaction in the plasmaspheric plume. Therefore, the paper provides a direct proof that EMIC waves can be generated in the plasmaspheric plume and scatter RC ions to cause subauroral proton arcs.

Electron Cloud Mitigation in the Spallation Neutron Source Ring

International Nuclear Information System (INIS)

Wei, J.; Blaskiewicz, Michael; Brodowski, J.; Cameron, P.; Davino, Daniele; Fedotov, A.; He, P.; Hseuh, H.; Lee, Y.Y.; Ludewig, H.; Meng, W.; Raparia, D.; Tuozzolo, J.; Zhang, S.Y.; Catalan-Lasheras, N.; Macek, R.J.; Furman, Miguel A.; Aleksandrov, A.; Cousineau, S.; Danilov, V.; Henderson, S.

2008-01-01

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H - injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation

Electron-cloud mitigation in the spallation neutron source ring

International Nuclear Information System (INIS)

Wei, J.; Blaskiewicz, M.; Brodowski, J.; Cameron, P.; Davino, D.; Fedotov, A.; He, P.; Hseuh, H.; Lee, Y.Y.; Meng, W.; Raparia, D.; Tuozzolo, J.; Zhang, S.Y.; Danilov, V.; Henderson, S.; Furman, M.; Pivi, M.; Macek, R.

2003-01-01

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H- injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation

Spin dynamics at level crossing in molecular AF rings probed by NMR

Energy Technology Data Exchange (ETDEWEB)

Lascialfari, A. E-mail: lascialfari@fisicavolta.unipv.it; Borsa, F.; Julien, M.-H.; Micotti, E.; Furukawa, Y.; Jang, Z.H.; Cornia, A.; Gatteschi, D.; Horvatic, M.; Van Slageren, J

2004-05-01

The low-temperature spin dynamics in molecular rings with a finite number (N{<=}10) of magnetic ions was studied by means of {sup 1}H NMR. When an external magnetic field (B) induces a crossing between energy levels, peaks are observed in the spin-lattice relaxation rate of protons, 1/T{sub 1}(B), at constant temperature. We discuss similarities and differences in the data from three different rings: Fe10, Fe6:Li and Cr8.

Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)](-) anionic complex.

Science.gov (United States)

Graham, Jacob D; Buytendyk, Allyson M; Zhang, Xinxing; Kim, Seong K; Bowen, Kit H

2015-11-14

The [Co(Pyridine)(CO2)](-) anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)](-) in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)]- anionic complex

Science.gov (United States)

Graham, Jacob D.; Buytendyk, Allyson M.; Zhang, Xinxing; Kim, Seong K.; Bowen, Kit H.

2015-11-01

The [Co(Pyridine)(CO2)]- anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)]- in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

Removal of pyridine and quinoline by bio-zeolite composed of mixed degrading bacteria and modified zeolite

International Nuclear Information System (INIS)

Bai Yaohui; Sun Qinghua; Xing Rui; Wen Donghui; Tang Xiaoyan

2010-01-01

In the process of the biodegradation of pyridine and quinoline, ammonium is often generated because of the transformation of N from pyridine and quinoline. Zeolite has been proven to be an effective sorbent for the removal of the ammonium. The natural zeolite can be modified to be the macroporous carrier in the biological wastewater treatment process. In this study, a specific bio-zeolite composed of mixed bacteria (a pyridine-degrading bacterium and a quinoline-degrading bacterium) and modified zeolite was used for biodegradation and adsorption in two types of wastewater: sterile synthetic and coking wastewater. The experimental results indicated that pyridine and quinoline could be degraded simultaneously by the mixed bacteria. Furthermore, NH 4 + -N transformed from pyridine and quinoline could be removed by the modified zeolite. In addition, the bacterial community structures of the coking wastewater and the bio-zeolite were monitored by the amplicon length heterogeneity polymerase-chain reaction (LH-PCR) technique. Both LH-PCR results and scanning electron microscope (SEM) observations indicated that the microorganisms, including BW001 and BW003, could be easily attached on the surface of the modified zeolite and that the bio-zeolite could be used in the treatment of wastewater containing pyridine and/or quinoline.

Dynamics of RF captured cooled proton beams

International Nuclear Information System (INIS)

Kells, W.; Mills, F.

1983-01-01

In the course of electron cooling experiments at the Electron Cooling Ring (ECR) at Fermilab, several peculiar features of the longitudinal phase space of cold protons (200 MeV) captured in RF buckets were observed. Here we present the experimental facts, present a simple theory, and summarize computer simulation results which support the theory and facts

Location of protons in N-H···N hydrogen-bonded systems: a theoretical study on intramolecular pyridine-dihydropyridine and pyridine-pyridinium pairs.

Science.gov (United States)

Mori, Yukie; Takano, Keiko

2012-08-21

Two-dimensional potential energy surfaces (PESs) were calculated for the degenerate intramolecular proton transfer (PT) in two N-H···N hydrogen-bonded systems, (Z)-2-(2-pyridylmethylidene)-1,2-dihydropyridine (1) and monoprotonated di(2-pyridyl) ether (2), at the MP2/cc-pVDZ level of theory. The calculated PES had two minima in both cases. The energy barrier in 1 was higher than the zero-point energy (ZPE) level, while that in 2 was close to the ZPE. Vibrational wavefunctions were obtained by solving time-independent Schrödinger equations with the calculated PESs. The maximum points of the probability density were shifted from the energy minima towards the region where the covalent N-H bond was elongated and the N···N distance shortened. The effects of a polar solvent on the PES were investigated with the continuum or cluster models in such a way that the solute-solvent electrostatic interactions could be taken into account under non-equilibrated conditions. A solvated contact ion-pair was modelled by a cluster consisting of one cation 2, one chloride ion and 26 molecules of acetonitrile. The calculation with this model suggested that the bridging proton is localised in the deeper well due to the significant asymmetry of the PES and the high potential barrier.

Beam-beam force and storage ring parameters

International Nuclear Information System (INIS)

Herrera, J.C.

1979-01-01

The fundamental aspects of the beam--beam force as it occurs in Intersecting Storage Rings are reported. The way in which the effect of the beam--particle electromagnetic force (weak--strong interaction) is different in the case of unbunched proton beams which cross each other at an angle (as in the ISR and in ISABELLE) is shown, as compared to the case of electron--positron beams where bunches collide head-on

DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS

International Nuclear Information System (INIS)

HE, P.; HSEUH, H.C.; MAPES, M.; TODD, R.; WEISS, D.

2001-01-01

The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with ∼100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DC-magnetron sputtering were conducted in a test chamber of relevant geometry to SNS ring vacuum chambers. Auger Electron Spectroscopy (AES) and Rutherford Back Scattering (RBS) were used to analyze the coatings for thickness, stoichiometry and impurity. Excellent results were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented

The 400 GeV proton synchrotron

International Nuclear Information System (INIS)

1976-05-01

A general account is given of the 400-GeV proton synchrotron, known as Super Proton Synchrotron (SPS), of the European Organization for Nuclear Research (CERN) at Geneva. A brief chapter on the history of the project covers the steps leading to the earlier plan for a 300-GeV accelerator at a new CERN laboratory elsewhere in Europe, abandoned in 1971 in favour of the present machine, and the progress of construction of the latter. The general features of the SPS design are outlined, illustrated by an aerial view of the CERN site, a plan of the SPS, and interior views of the SPS ring tunnel and main control room. (WSN)

Positron Options for the Linac-Ring LHeC

CERN Document Server

Zimmermann, F; Papaphilippou, Y; Schulte, D; Sievers, P; Rinolfi, L; Variola, A; Zomer, F; Braun, H H; Yakimenko, V; Bulyak, E V; Klein, M

2012-01-01

The full physics program of a future Large Hadron electron Collider (LHeC) [1] requires both pe+ and pe− collisions. For a pulsed 140-GeV or an ERL-based 60-GeV Linac-Ring LHeC this implies a challenging rate of, respectively, about 1.8 × 1015 or 4.4 × 1016 e+/s at the collision point, which is about 300 or 7000 times the rate previously obtained, at the SLAC Linear Collider (SLC). We consider providing this e+ rate through a combination of measures: (1) Reducing the required production rate from the e+ target through colliding e+ (and the LHC protons) several times before deceleration, by reusing the e+ over several acceleration/deceleration cycles, and by cooling them, e.g., with a compact tri-ring scheme or a conventional damping ring in the SPS tunnel. (2) Using an advanced target, e.g., W-granules, rotating wheel, slicedrod converter, or liquid metal jet, for converting gamma rays to e+. (3) Selecting the most powerful of several proposed gamma sources, namely Compton ERL, Compton storage ring, coher...

RHIC polarized proton-proton operation at 100 GeV in Run 15

International Nuclear Information System (INIS)

Schoefer, V.; Aschenauer, E. C.; Atoian, G.; Blaskiewicz, M.; Brown, K. A.; Bruno, D.; Connolly, R.; D Ottavio, T.; Drees, K. A.; Dutheil, Y.; Fischer, W.; Gardner, C.; Gu, X.; Hayes, T.; Huang, H.; Laster, J.; Liu, C.; Luo, Y.; Makdisi, Y.; Marr, G.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R.; Marusic, A.; Minty, M.; Montag, C.; Morris, J.; Narayan, G.; Nemesure, S.; Pile, P.; Poblaguev, A.; Ranjbar, V.; Robert-Demolaize, G.; Roser, T.; Schmidke, W. B.; Severino, F.; Shrey, T.; Smith, K.; Steski, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; White, S.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S. Y.

2015-01-01

The first part of RHIC Run 15 consisted of ten weeks of polarized proton on proton collisions at a beam energy of 100 GeV at two interaction points. In this paper we discuss several of the upgrades to the collider complex that allowed for improved performance. The largest effort consisted in commissioning of the electron lenses, one in each ring, which are designed to compensate one of the two beam-beam interactions experienced by the proton bunches. The e-lenses raise the per bunch intensity at which luminosity becomes beam-beam limited. A new lattice was designed to create the phase advances necessary for a beam-beam compensation with the e-lens, which also has an improved off-momentum dynamic aperture relative to previous runs. In order to take advantage of the new, higher intensity limit without suffering intensity driven emittance deterioration, other features were commissioned including a continuous transverse bunch-by-bunch damper in RHIC and a double harmonic RF cature scheme in the Booster. Other high intensity protections include improvements to the abort system and the installation of masks to intercept beam lost due to abort kicker pre-fires.

Coulomb collisions of ring current particles: Indirect source of heat for the ionosphere

Science.gov (United States)

Cole, K. D.

1975-01-01

The additional energy requirements of the topside ionosphere during a magnetic storm are less than one quarter of the ring current energy. This energy is supplied largely by Coulomb collisions of ring current protons of energy less than about 20 keV with background thermal electrons which conduct the heat to the ionosphere. Past criticisms are discussed of this mechanism for the supply of energy to the SAR-arc and neighboring regions of the ionosphere.

First high-power model of the annular-ring coupled structure for use in the Japan Proton Accelerator Research Complex linac

Directory of Open Access Journals (Sweden)

Hiroyuki Ao

2012-01-01

Full Text Available A prototype cavity for the annular-ring coupled structure (ACS for use in the Japan Proton Accelerator Research Complex (J-PARC linac has been developed to confirm the feasibility of achieving the required performance. This prototype cavity is a buncher module, which includes ten accelerating cells in total. The ACS cavity is formed by the silver brazing of ACS half-cell pieces stacked in a vacuum furnace. The accelerating cell of the ACS is surrounded by a coupling cell. We, therefore, tuned the frequencies of the accelerating and coupling cells by an ultraprecision lathe before brazing, taking into account the frequency shift due to brazing. The prototype buncher module was successfully conditioned up to 600 kW, which corresponds to an accelerating field that is higher than the designed field of 4.1  MV/m by 30%. We describe the frequency-tuning results for the prototype buncher module and its high-power conditioning.

Computational, electrochemical, and spectroscopic studies of two mononuclear cobaloximes: the influence of an axial pyridine and solvent on the redox behaviour and evidence for pyridine coordination to cobalt(I) and cobalt(II) metal centres†

Science.gov (United States)

Lawrence, Mark A. W.; Celestine, Michael J.; Artis, Edward T.; Joseph, Lorne S.; Esquivel, Deisy L.; Ledbetter, Abram J.; Cropek, Donald M.; Jarrett, William L.; Bayse, Craig A.; Brewer, Matthew I.; Holder, Alvin A.

2018-01-01

[Co(dmgBF2)2(H2O)2] 1 (where dmgBF2 = difluoroboryldimethylglyoximato) was used to synthesize [Co(dmgBF2)2(H2O)(py)]·0.5(CH3)2CO 2 (where py = pyridine) in acetone. The formulation of complex 2 was confirmed by elemental analysis, high resolution MS, and various spectroscopic techniques. The complex [Co(dmgBF2)2(solv)(py)] (where solv = solvent) was readily formed in situ upon the addition of pyridine to complex 1. A spectrophotometric titration involving complex 1 and pyridine proved the formation of such a species, with formation constants, log K = 5.5, 5.1, 5.0, 4.4, and 3.1 in 2-butanone, dichloromethane, acetone, 1,2-difluorobenzene/acetone (4 : 1, v/v), and acetonitrile, respectively, at 20 °C. In strongly coordinating solvents, such as acetonitrile, the lower magnitude of K along with cyclic voltammetry, NMR, and UV-visible spectroscopic measurements indicated extensive dissociation of the axial pyridine. In strongly coordinating solvents, [Co(dmgBF2)2(solv)(py)] can only be distinguished from [Co(dmgBF2)2(solv)2] upon addition of an excess of pyridine, however, in weakly coordinating solvents the distinctions were apparent without the need for excess pyridine. The coordination of pyridine to the cobalt(II) centre diminished the peak current at the Epc value of the CoI/0 redox couple, which was indicative of the relative position of the reaction equilibrium. Herein we report the first experimental and theoretical 59Co NMR spectroscopic data for the formation of Co(I) species of reduced cobaloximes in the presence and absence of py (and its derivatives) in CD3CN. From spectroelectrochemical studies, it was found that pyridine coordination to a cobalt(I) metal centre is more favourable than coordination to a cobalt(II) metal centre as evident by the larger formation constant, log K = 4.6 versus 3.1, respectively, in acetonitrile at 20 °C. The electrosynthesis of hydrogen by complexes 1 and 2 in various solvents demonstrated the dramatic effects of the axial

Colliding or co-rotating ion beams in storage rings for EDM search

International Nuclear Information System (INIS)

Koop, I A

2015-01-01

A new approach to search for and measure the electric dipole moment (EDM) of the proton, deuteron and some other light nuclei is presented. The idea of the method is to store two ion beams, circulating with different velocities, in a storage ring with crossed electric and magnetic guiding fields. One beam is polarized and its EDM is measured using the so-called ‘frozen spin’ method. The second beam, which is unpolarized, is used as a co-magnetometer, sensitive to the radial component of the ring’s magnetic field. The particle’s magnetic dipole moment (MDM) couples to the radial magnetic field and mimics the EDM signal. Measuring the relative vertical orbit separation of the two beams, caused by the presence of the radial magnetic field, one can control the unwanted MDM spin precession. Examples of the parameters for EDM storage rings for protons and other species of ions are presented. The use of crossed electric and magnetic fields helps to reduce the size of the ring by a factor of 10–20. We show that the bending radius of such an EDM storage ring could be about 2–3 m. Finally, a new method of increasing the spin coherence time, the so-called ‘spin wheel’, is proposed and its applicability to the EDM search is discussed. (paper)

Simulation of spin dynamics to measure electric dipole moments in storage rings

Energy Technology Data Exchange (ETDEWEB)

Rosenthal, Marcel; Lehrach, Andreas [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik; Collaboration: JEDI-Collaboration

2013-07-01

CP violation in the baryon sector, which is predicted by the Standard Model of Particle Physics, is too small to explain the matter and antimatter asymmetry in our universe. Permanent Electric Dipole Moments (EDMs) violate both P and T symmetries and are therefore, through the CPT theorem, also CP violating. No direct EDM measurements for protons, deuterons and light nuclei have been performed up to now. The JEDI collaboration at Forschungszentrum Juelich (FZJ) and the BNL-EDM collaboration at Brookhaven National Laboratory (BNL) pursue the goal to measure the EDMs of these particles in dedicated storage rings. Therefore different approaches are studied to reach an ultimate sensitivity of 10{sup -29} e.cm. A first direct measurement of the proton and deuteron EDM at a sensitivity level of 10{sup -24} e.cm will be performed in the existing conventional storage ring at FZJ, the Cooler Synchrotron COSY. Particle tracking simulations to explore the motion-correlated spin dynamics are a crucial part of feasibility studies of the planned storage ring EDM experiments. In a first step, a benchmarking of simulation codes with measurements at the Cooler Synchrotron COSY is performed.

Potentiometric and ab initio studies of acid-base interactions of substituted 4-halo(Cl, Br)pyridine N-oxide systems

International Nuclear Information System (INIS)

Gurzynski, Lukasz; Puszko, Aniela; Makowski, Mariusz; Makowska, Joanna; Chmurzynski, Lech

2006-01-01

By using the potentiometric method, acidity constants have been determined in systems of tri- and tetra-substituted pyridine N-oxides. The potentiometric measurements in systems of four 4-chloropyridine N-oxide derivatives containing the chlorine atom at position 4 to the NO 2 group and four bromine counterparts were carried out in polar non-aqueous solvents, viz. amphiprotic methanol (MeOH) and aprotic protophilic dimethyl sulfoxide (DMSO). It was found that in all the systems studied the pK a values were readily determinable (as indicated by small standard deviations) in MeOH, whereas in DMSO large standard deviations were obtained making the pK a values either hardly determinable or indeterminable from potentiometric measurements. Furthermore, it was demonstrated that the acidity constants of protonated N-oxides studied in MeOH changed according to the sequence of their acidity constants in water. It was also found that in the polar solvents studied, i.e. in the amphiprotic methanol and the highly basic aprotic dimethyl sulfoxide, the cationic homo-conjugation equlibrium constants could not be determined using potentiometric method. Also, by using ab initio methods at the RHF and MP2 levels and the PCM model, utilizing the Gaussian 6-31++G** basis set, energies and Gibbs free energies of the protonation reactions of the N-oxides have been determined. The energy parameters have been compared with acidity constants of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these approaches

Dihydro-β-agarofuran sesquiterpene pyridine alkaloids from the seeds of Euonymus hamiltonianus

Directory of Open Access Journals (Sweden)

Mudasir A. Tantry

2016-09-01

Full Text Available Plants of the Celastraceae family produce various dihydro-β-agarofuran sesquiterpene pyridine alkaloids. Two dihydro-β-agarofuran sesquitepene pyridine alkaloids (1,2 apart from four known compounds euojaponin C (3, wilforine (4, austronine (5 and O9-benzoyl-O9-deacetylevonine (6, were isolated from the ripe seeds of Euonymus hamiltonianus. Their chemical structures were elucidated mainly by analysis of NMR and MS spectral data. All compounds were evaluated for insecticidal activity.

Production and characterization of protonated molecular clusters containing a given number of water molecules with the DIAM set-up

International Nuclear Information System (INIS)

Bruny, G.

2010-01-01

nano-scale characterization of irradiation in bio-molecular systems requires observation of novel features which are now achievable with the recent technical progress. This work is a central part in the development of DIAM which is a new experimental set-up devoted to irradiation of bio-molecular clusters at the Institut de Physique Nucleaire de Lyon. The development of the cluster source and of a double focusing mass spectrometer leads to the production of intense beams of mass selected protonated molecular clusters. Combined with this mass selected cluster beams an innovative detection technique is demonstrated in collision induced dissociation experiments. The results contribute to the knowledge of the stability and the structure of the small protonated water clusters and mixed clusters of water and pyridine. (author)

Studies and calculations of transverse emittance growth in proton storage rings

International Nuclear Information System (INIS)

Mane, S.R.; Jackson, G.

1989-01-01

When high energy storage rings are used to collide beams of particles and antiparticles for high energy physics experiments, it is important to obtain as high an integrated luminosity as possible. Reduction of integrated luminosity can arise from several factors, in particular from growth of the transverse beam sizes (transverse emittances). We have studied the problem of transverse emittance growth in high energy storage rings caused by random dipole noise kicks to the beam. A theoretical formula for the emittance growth rate is derived, and agreement is obtained with experimental measurements where noise of known amplitude and power spectrum was deliberately injected into the Fermilab Tevatron, to kick the beam randomly. In the experiment, phase noise was introduced into the Tevatron rf system, and the measured dependence of horizontal emittance growth on phase noise amplitude is compared against the theoretically derived response. (orig.)

Status of the MEIC ion collider ring design

International Nuclear Information System (INIS)

Morozov, Vasiliy; Derbenev, Yaroslav; Harwood, Leigh; Hutton, Andrew; Lin, Fanglei; Pilat, Fulvia; Zhang, Yuhong; Cai, Yunhai; Nosochkov, Y. M.; Sullivan, Michael; Wang, M.-H.; Wienands, Uli; Gerity, James; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

2015-09-01

We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

Status of the MEIC ion collider ring design

International Nuclear Information System (INIS)

Morozov, V. S.; Derbenev, Ya. S.; Harwood, L.; Hutton, A.; Lin, F.; Pilat, F.; Zhang, Y.; Cai, Y.; Nosochkov, Y. M.; Sullivan, M.; Wang, M-H; Wienands, U.; Gerity, J.; Mann, T.; McIntyre, P.; Pogue, N. J.; Satttarov, A.

2015-01-01

We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated superconducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

Pyridine Vapors Detection by an Optical Fibre Sensor

Directory of Open Access Journals (Sweden)

Alberto Fernandez-Gutiérrez

2008-02-01

Full Text Available An optical fibre sensor has been implemented towards pyridine vapors detection;to achieve this, a novel vapochromic material has been used, which, in solid state, suffers achange in colour from blue to pink-white in presence of pyridine vapours. This complex isadded to a solution of PVC (Poly Vinyl Chloride, TBP (Tributylphosphate andtetrahydrofuran (THF, forming a plasticized matrix; by dip coating technique, the sensingmaterial is fixed onto a cleaved ended optical fibre. The fabrication process was optimizedin terms of number of dips and dipping speed, evaluating the final devices by dynamicrange. Employing a reflection set up, the absorbance spectra and changes in the reflectedoptical power of the sensors were registered to determine their response. A linear relationbetween optical power versus vapor concentration was obtained, with a detection limit of 1ppm (v/v.

Design of a High Luminosity 100 TeV Proton Antiproton Collider

Energy Technology Data Exchange (ETDEWEB)

Oliveros Tuativa, Sandra Jimena [Univ. of Mississippi, Oxford, MS (United States)

2017-04-01

Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10$^{\\,34}$ cm$^{-2}$ s$^{-1}$ luminosity 100 TeV proton-antiproton collider is explored with 7$\\times$ the energy of the LHC. The dipoles are 4.5\\,T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in $p\\bar{p}$ than $pp$ collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $\\beta^{*}$ for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

Design of a High Luminosity 100 TeV Proton-Antiproton Collider

Science.gov (United States)

Oliveros Tautiva, Sandra Jimena

Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10 34 cm-2 s-1 luminosity 100 TeV proton-antiproton collider is explored with 7x the energy of the LHC. The dipoles are 4.5 T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in pp than pp collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller beta* for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

Recent results from the CELSIUS/WASA collaboration on meson production in proton-hydrogen collisions

International Nuclear Information System (INIS)

Bilger, R.; Bondar, A.; Brodowski, W.; Calen, H.; Clement, H.; Dyring, J.; Ekstroem, C.; Fransson, K.; Gustafsson, L.; Haeggstroem, S.; Hoeistad, B.; Johanson, J.; Johansson, A.; Johansson, T.; Kilian, K.; Kullander, S.; Kupsc, A.; Kuzmin, A.; Marciniewski, P.; Morosov, B.; Moertsell, A.; Oelert, W.; Povtorejko, A.; Ruber, R.J.M.Y.; Schuberth, U.; Sefzick, T.; Sidorov, V.; Shwartz, B.; Sopov, V.; Stepaniak, J.; Sukhanov, A.; Sukhanov, A.; Tchernychev, V.; Turowiecki, A.; Wagner, G.; Wilhelmi, Z.; Zabierowski, J.; Zernov, A.; Zlomanczuk, J.

1999-01-01

Different π and η meson production channels in proton-proton and proton-deuteron collisions have been studied at the CELSIUS storage ring using an internal cluster-jet target setup [1]. During the last years more emphasis has been put on ππ and all but one of the possible channels in proton-proton collisions have been studied. Recently also the quasi-free p+n→d+η reaction cross section has been measured at threshold using 1295 MeV protons and target deuterium. Excess energies from threshold to 10 MeV in the center of mass of the final dη system were covered. Approaching the threshold the cross section is enhanced compared to phase-space expectations. This behaviour is typical for a strong final-state interaction

Crystal structure of bis­(3-bromo­pyridine-κN)bis­(O-ethyl di­thio­carbonato-κ2 S,S′)nickel(II)

Science.gov (United States)

Kant, Rajni; Kour, Gurvinder; Anthal, Sumati; Neerupama; Sachar, Renu

2015-01-01

In the title mol­ecular complex, [Ni(C3H5OS2)2(C5H4BrN)2], the Ni2+ cation is located on a centre of inversion and has a distorted octa­hedral N2S4 environment defined by two chelating xanthate ligands and two monodentate pyridine ligands. The C—S bond lengths of the thio­carboxyl­ate group are indicative of a delocalized bond and the O—Csp 2 bond is considerably shorter than the O—Csp 3 bond, consistent with a significant contribution of one resonance form of the xanthate anion that features a formal C=O+ unit and a negative charge on each of the S atoms. The packing of the mol­ecules is stabilized by C—H⋯S and C—H⋯π inter­actions. In addition, π–π inter­actions between the pyridine rings [centroid-to-centroid distance = 3.797 (3) Å] are also present. In the crystal structure, mol­ecules are arranged in rows along [100], forming layers parallel to (010) and (001). PMID:25705471

Feedback to suppress beam instabilities in future proton rings

International Nuclear Information System (INIS)

Lambertson, G.R.

1985-05-01

Criteria for the design of feedback systems to suppress coherent beam instabilities are presented. These address starting amplitudes, diffusion from noise during damping or long storage, and choice of kicker. As a model for future accelerators, specifications of the proposed 20 TeV SSC are used to calculate parameters of systems to control expected instabilities. A scenario and hardware to stabilize the transverse mode-coupling instability is examined. The scale of the systems is large but not out of scale with the large ring. 9 refs., 4 tabs

Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel 1-(1H-benzimidazol-6-yl)pyridin-2(1H)-one derivatives and design to avoid CYP3A4 time-dependent inhibition.

Science.gov (United States)

Igawa, Hideyuki; Takahashi, Masashi; Shirasaki, Mikio; Kakegawa, Keiko; Kina, Asato; Ikoma, Minoru; Aida, Jumpei; Yasuma, Tsuneo; Okuda, Shoki; Kawata, Yayoi; Noguchi, Toshihiro; Yamamoto, Syunsuke; Fujioka, Yasushi; Kundu, Mrinalkanti; Khamrai, Uttam; Nakayama, Masaharu; Nagisa, Yasutaka; Kasai, Shizuo; Maekawa, Tsuyoshi

2016-06-01

Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents, and numerous drug discovery programs are dedicated to finding small-molecule MCH receptor 1 (MCHR1) antagonists. We recently reported novel pyridine-2(1H)-ones as aliphatic amine-free MCHR1 antagonists that structurally featured an imidazo[1,2-a]pyridine-based bicyclic motif. To investigate imidazopyridine variants with lower basicity and less potential to inhibit cytochrome P450 3A4 (CYP3A4), we designed pyridine-2(1H)-ones bearing various less basic bicyclic motifs. Among these, a lead compound 6a bearing a 1H-benzimidazole motif showed comparable binding affinity to MCHR1 to the corresponding imidazopyridine derivative 1. Optimization of 6a afforded a series of potent thiophene derivatives (6q-u); however, most of these were found to cause time-dependent inhibition (TDI) of CYP3A4. As bioactivation of thiophenes to form sulfoxide or epoxide species was considered to be a major cause of CYP3A4 TDI, we introduced electron withdrawing groups on the thiophene and found that a CF3 group on the ring or a Cl adjacent to the sulfur atom helped prevent CYP3A4 TDI. Consequently, 4-[(5-chlorothiophen-2-yl)methoxy]-1-(2-cyclopropyl-1-methyl-1H-benzimidazol-6-yl)pyridin-2(1H)-one (6s) was identified as a potent MCHR1 antagonist without the risk of CYP3A4 TDI, which exhibited a promising safety profile including low CYP3A4 inhibition and exerted significant antiobesity effects in diet-induced obese F344 rats. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new multicomponent reaction for the synthesis of pyridines via cycloaddition of azadienes and ketenimines

NARCIS (Netherlands)

Coffinier, D.; El Kaim, L.; Grimaud, L.; Ruijter, E.; Orru, R.V.A.

2011-01-01

The ketenimines resulting from a Nef isocyanide/Perkow sequence react with 1-azadienes to form pyridines or pyrimidines depending on their substitution pattern. The reaction is most efficient with ester-substituted ketenimines which leads to pyridines after elimination of the phosphate group. © 2011

Diverse Reactions of Thiophenes, Selenophenes, and Tellurophenes with Strongly Oxidizing I(III) PhI(L)2 Reagents.

Science.gov (United States)

Egalahewa, Sathsara; Albayer, Mohammad; Aprile, Antonino; Dutton, Jason L

2017-02-06

We report the outcomes of the reactions of aromatic group 16 thiophene, selenophene, and tellurophene rings with the I(III) oxidants PhI(OAc)(OTf) and [PhI(Pyr) 2 ][OTf] 2 (Pyr = pyridine). In all reactions, oxidative processes take place, with generation of PhI as the reduction product. However, with the exception of tellurophene with PhI(OAc)(OTf), +4 oxidation state complexes are not observed, but rather a variety of other processes occur. In general, where a C-H unit is available on the 5-membered ring, an electrophilic aromatic substitution reaction of either -IPh or pyridine onto the ring occurs. When all positions are blocked, reactions with PhI(OAc)(OTf) give acetic and triflic anhydride as the identifiable oxidative byproducts, while [PhI(Pyr) 2 ][OTf] 2 gives pyridine electrophilic aromatic substitution onto the peripheral rings. Qualitative mechanistic studies indicate that the presence of the oxidizable heteroatom is required for pyridine to act as an electrophile in a substantial manner.

Elementary design of a 30 TeV on 30 TeV proton antiproton collider

International Nuclear Information System (INIS)

Kondo, Takahiko

1984-01-01

A crude conceptual design was made for a 30TeV on 30TeV antiproton-proton collider. The choice of energy and antiproton-proton (instead of PP) are somewhat arbitrary. The basic parameters of the main ring are listed in a table; the bending radius, ring radius and circumference are 11.1km, 14.4km, and 90.6km, respectively; 7680 dipole magnets with maximum field of 9 Tesla; 1280 quadrupole magnets with maximum gradient of 200Tesla/m. The development of high-field, low-heat loss dipoles and quadrupoles are essential, together with the consideration for their mass production method. On the other hand, the possibility of obtaining antiproton-proton luminosity exceeding 10 32 /cm 2 sec is suggested without any fundamental limitation. With such high luminosity, however, it should be pointed out that particle detectors must face their limitation due to extremely high rate, high multiplicity interaction, requiring large steps of detector research and development efforts. (Aoki, K.)

A Ring Imaging Cerenkov detector for the CERN OMEGA spectrometer

International Nuclear Information System (INIS)

Apsimon, R.J.; Cowell, J.; Flower, P.S.

1984-12-01

A large acceptance Ring Imaging Cerenkov detector has been constructed for use at the CERN Omega Spectrometer. The design of the detector is discussed, with attention paid to its principal components, and preliminary results are given which show that the detector is capable of identifying pions and protons at 100 GeV/c. (author)

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

Directory of Open Access Journals (Sweden)

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.

Anisotropic amplification of proton transport in proton exchange membrane fuel cells

Science.gov (United States)

Thimmappa, Ravikumar; Fawaz, Mohammed; Devendrachari, Mruthyunjayachari Chattanahalli; Gautam, Manu; Kottaichamy, Alagar Raja; Shafi, Shahid Pottachola; Thotiyl, Musthafa Ottakam

2017-07-01

Though graphene oxide (GO) membrane shuttles protons under humid conditions, it suffer severe disintegration and anhydrous conditions lead to abysmal ionic conductivity. The trade-off between mechanical integrity and ionic conductivity challenge the amplification of GO's ionic transport under anhydrous conditions. We show anisotropic amplification of GO's ionic transport with a selective amplification of in plane contribution under anhydrous conditions by doping it with a plant extract, phytic acid (PA). The hygroscopic nature of PA stabilized interlayer water molecules and peculiar geometry of sbnd OH functionalities around saturated hydrocarbon ring anisotropically enhanced ionic transport amplifying the fuel cell performance metrics.

New pinene-derived pyridines as bidentate chiral ligands

Czech Academy of Sciences Publication Activity Database

Malkov, A. V.; Stewart-Liddon, A.; Teplý, Filip; Kobr, L.; Muir, K. W.; Haigh, D.; Kočovský, P.

2008-01-01

Roč. 64, č. 18 (2008), s. 4011-4025 ISSN 0040-4020 Institutional research plan: CEZ:AV0Z40550506 Keywords : chiral ligands * transition metal catalysis * asymmetric catalysis * pyridine ligands * oxazoline ligands Subject RIV: CC - Organic Chemistry Impact factor: 2.897, year: 2008

Crystal Structure and Properties of Imidazo-Pyridine Ionic Liquids.

Science.gov (United States)

Farren-Dai, Marco; Cameron, Stanley; Johnson, Michel B; Ghandi, Khashayar

2018-07-05

Computational studies were performed on novel protic ionic liquids imidazolium-[1,2-a]-pyridine trifluoroacetate [ImPr][TFA] synthesized by the reaction of imidazo-[1,2a]-pyridine (ImPr) with trifluoroacetic acid (TFA), and on fused salt imidazolium-[1,2-a]-pyridine maleamic carbonate [ImPr][Mal] synthesized by reaction of ImPr with maleamic acid (Mal). Synthesis was performed as one-pot reactions, which applies green chemistry tenets. Both these compounds begin to decompose at 180°C. Our computational studies suggest another thermal reaction channel, in which [ImPr][Mal] can also thermally polymerizes to polyacrylamide which then cyclizes. This is thermal product remains stable up to 700 degrees, consistent with our thermogravimetric studies. [ImPr][TFA] exhibited good conductivity and ideal ionic behavior, as evaluated by a Walden plot. X-ray crystallography of [ImPr][TFA] revealed a tightly packed system for the crystals as a result of strong ionic interaction, pi-stacking, and fluorine-CH interactions. Both synthesized compounds exhibited some CO 2 absorptivity, with [ImPr][Mal] outperforming [ImPr][TFA] in this regard. The quantum chemistry based computational methods can shed light on many properties of these ionic liquids, but they are challenged in fully describing their ionic nature. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Passive filter of the IFVE accelerator ring electromagnet

International Nuclear Information System (INIS)

Kaz'min, B.V.; Mojzhes, L.L.; Polyakov, Eh.V.; Radin, O.N.; Fedorov, Yu.A.

1977-01-01

Two circuits of two-link passive filters for suppressing the current pulsation in the ring electromagnet of a synchrotron are presented, as well as calculated and experimental (for one of the circuits) characteristics of these filters. It is shown that the coefficient of suppression of 600 hertz pulsations in the flat portion of a magnetic field pulse is 570 at an intensity corresponding to a slow proton ejection

Thermometric titration of acids in pyridine.

Science.gov (United States)

Vidal, R; Mukherjee, L M

1974-04-01

Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

Electron-muon coincidences in proton-proton collisions at the CERN Intersecting Storage Rings

CERN Document Server

Clark, A G; Darriulat, Pierre; Eggert, K; Hungerbühler, V; Jenni, Peter; Lapuyade, C; Modis, T; Pérez, P; Renshall, H; Richter, Burton; Smadja, G; Strauss, J; Strolin, P; Tarnopolsky, G J; Teiger, J; Tur, C; Vialle, J P; Zaccone, Henri; Zallo, A; Zylberstejn, A

1978-01-01

In an experiment carried out at the CERN Intersecting Storage Rings with a highly selective electron spectrometer system and a magnetized iron filter to detect muons, the authors have observed 32+or-16 dilepton events of the type p+p to mu /sup +or-/+e/sup -or+/+... The integrated luminosity of the experiment was (2.0+or-0.1)*10/sup 37/ cm /sup -2/, and the over-all detection efficiency 0.14+or-0.07. Interpreting this signal as due to charmed meson-pair production, the authors estimate a model-dependent acceptance of 6.5*10/sup -5/ per event, and a cross-section sigma (p+p to D+D+...)=(18+or-9) mu b, with a scale uncertainty of 50% due to the detection efficiency. (9 refs).

Diaqua­bis­(pyridine-2-carboxyl­ato-κ2 N,O)manganese(II) dimethyl­formamide hemisolvate

Science.gov (United States)

Golenya, Irina A.; Boyko, Alexander N.; Kalibabchuk, Valentina A.; Haukka, Matti; Tomyn, Stefania V.

2011-01-01

There are two crystallographically independent complex mol­ecules with very similar geometries in the unit cell of the title compound, [Mn(C6H4NO2)2(H2O)2]·0.5C3H7NO. The central ion is situated in a distorted octa­hedral environment of two N- and four O-donor atoms from two pyridine-2-carboxyl­ate ligands and two cis-disposed water mol­ecules. The carboxyl­ate ligands are coordinated in a chelate fashion with the formation of two five-membered rings. In the crystal, the complex mol­ecules are connected by O—H⋯O hydrogen bonds between the coordinated water mol­ecules and the uncoordinated carboxyl­ate O atoms, thus forming hydrogen-bonded walls disposed perpendicularly to the bc plane. PMID:22219799

Reactions of Cp2MCl2 (M=Ti or Zr with Imine-Oxime Ligands. Formation of Metallacycles

Directory of Open Access Journals (Sweden)

C. Tripathi

2005-07-01

Full Text Available The reactions of bis(cyclopentadienyltitanium(IV/zirconium(IV dichloridewith a series of imine-oxime ligands (LH2, derived by condensing benzil-α-monoxime and2-phenylenediamine, 4-phenylenediamine, 4-methyl-2-phenylenediamine, 2,6-diamino-pyridine, have been studied in anhydrous tetrahydrofuran in the presence of base andmetallocycles of the [Cp2M(L] (M=Ti or Zr type have been isolated. Tentative structureshave been proposed for the products based on elemental analysis, electrical conductance andspectral (electronic, IR and 1H-NMR data. Proton NMR spectra indicate that on the NMRtime scale there is rapid rotation of the cyclopentadienyl ring around the metal-ring axis at25oC. Studies were conducted to assess the growth inhibiting potential of the complexessynthesized and the ligands against various bacterial strains.

Crystal structure of a looped-chain CoII coordination polymer: catena-poly[[bis(nitrato-κOcobalt(II]bis[μ-bis(pyridin-3-ylmethylsulfane-κ2N:N′

Directory of Open Access Journals (Sweden)

Suk-Hee Moon

2017-11-01

Full Text Available The asymmetric unit of the title compound, [Co(NO32(C12H12N2S2]n, contains a bis(pyridin-3-ylmethylsulfane (L ligand, an NO3− anion and half a CoII cation, which lies on an inversion centre. The CoII cation is six-coordinated, being bound to four pyridine N atoms from four symmetry-related L ligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the CoII centre adopts a distorted octahedral geometry. Two symmetry-related L ligands are connected by two symmetry-related CoII cations, forming a 20-membered cyclic dimer, in which the CoII atoms are separated by 10.2922 (7 Å. The cyclic dimers are connected to each other by sharing CoII atoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Intermolecular C—H...π (H...ring centroid = 2.89 Å interactions between one pair of corresponding L ligands and C—H...O hydrogen bonds between the L ligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by intermolecular π–π stacking interactions [centroid-to-centroid distance = 3.8859 (14 Å] and C—H...π hydrogen bonds (H...ring centroid = 2.65 Å, leading to the formation of layers parallel to (101. These layers are further connected through C—H...O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supramolecular architecture.

Los Alamos Proton Storage Ring (PSR) injection deflector system

International Nuclear Information System (INIS)

Jason, A.j.; Higgins, E.F.; Koelle, A.R.

1983-01-01

We describe a pulsed magnetic deflector system planned for the injection system of the PSR. Two sets of magnets, appropriately placed in the optical systems of both the ring and the injection transport line, provide control of the rate at which particles are injected into a given portion of transverse phase space and limit the interaction of stored beam with the injection stripping foil. High-current modulators that produce relatively complex waveforms are required for this purpose. Solid-state drivers using direct feedback to produce the necessary waveforms are discussed as replacements for the more conventional high-voltage tube technology

Electron ring design for HERA, including spin-matching

International Nuclear Information System (INIS)

Skuja, A.; Hand, L.; Steffen, K.; Barber, D.

1984-01-01

A. Skuja has been working in collaboration with Professor Lou Hand in obtaining an optics for the electron ring at HERA that satisfies the usual constraints of an electron storage ring, but in addition allows longitudinal polarization in the interaction region without depolarizing the electron beam completely. This collaboration effort grew out of their work on a possible electron ring at Fermilab. When this project was degraded in priority at Fermilab, they turned their attention to the HERA project at DESY. The HERA project will have an electron ring of about 30 GeV e - (or e + ) incident on 800 GeV protons. Recently it has been decided that the collisions should be head on (0 0 crossing), although all previous designs had a crossing angle of the 2 beams of 20 mrad. Professors Hand and Skuja implemented a complete program in the last year and a half that could fit the usual Turis parameters as well as the so called 12 spin-matching conditions of Chao and Yukoya for all possible machine elements including solenoids. The program has the possibility of fully coupling vertical and horizontal motion using the usual eigenvalue method

Synthesis and crystal structures of 2-methyl-4-aryl-5-oxo-5H-indeno [1,2-b] pyridine carboxylate derivatives

DEFF Research Database (Denmark)

Pandian, Ramesh; Naushad, Edayadulla; Vijayakumar, Vinodhkumar

2014-01-01

pyridine derivatives through oxidation. Consequently, the interest in this aromatization reaction, investigation of a wide range of 1, 4-DHPs continues to attract the attention of researchers. Herein, we report the preparation of pyridine derivatives and the crystal structures determined by X......-ray crystallographic methods.Results: The crystal structures and conformational studies of two organic compounds, namely ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (I) and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (II) are reported. The terminal ethyl......) dimer running along 011 direction.Conclusion: The crystal structures ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate have been investigated in detail. The terminal ethyl group of compound I...

Concerning the generation of geomagnetic giant pulsations by drift-bounce resonance ring current instabilities

Directory of Open Access Journals (Sweden)

K.-H. Glassmeier

1999-03-01

Full Text Available Giant pulsations are nearly monochromatic ULF-pulsations of the Earth's magnetic field with periods of about 100 s and amplitudes of up to 40 nT. For one such event ground-magnetic observations as well as simultaneous GEOS-2 magnetic and electric field data and proton flux measurements made in the geostationary orbit have been analysed. The observations of the electromagnetic field indicate the excitation of an odd-mode type fundamental field line oscillation. A clear correlation between variations of the proton flux in the energy range 30-90 keV with the giant pulsation event observed at the ground is found. Furthermore, the proton phase space density exhibits a bump-on-the-tail signature at about 60 keV. Assuming a drift-bounce resonance instability as a possible generation mechanism, the azimuthal wave number of the pulsation wave field may be determined using a generalized resonance condition. The value determined in this way,  m = - 21 ± 4, is in accord with the value m = - 27 ± 6 determined from ground-magnetic measurements. A more detailed examination of the observed ring current plasma distribution function f shows that odd-mode type eigenoscillations are expected for the case ∂f / ∂W > 0, much as observed. This result is different from previous theoretical studies as we not only consider local gradients of the distribution function in real space, but also in velocity space. It is therefore concluded that the observed giant pulsation is the result of a drift-bounce resonance instability of the ring current plasma coupling to an odd-mode fundamental standing wave. The generation of the bump-on-the-tail distribution causing ∂f / ∂W > 0 can be explained due to velocity dispersion of protons injected into the ring current. Both this velocity dispersion and the necessary substorm activity causing the injection of protons into the nightside magnetosphere are observed.Key words. Magnetospheric physics (energetic particles , trapped

Surface enhanced raman scattering at Ag-Pyridine interface by use of long range surface plasmon

International Nuclear Information System (INIS)

Baik, Moon Gu; Ko, Eu; Kwan, Do Kyeong; Lee, Ja Hyung; Chang, Joon Sung

1990-01-01

Surface-enhanced Raman scattering (SERS) experiment of pyridine (C 5 H 5 N) has been performed at silverpyridine interface by use of long range surface plasmon (LRSP) which is generated in the Sarid-type attenuated total reflection (ATR) structure consisting of prism, dielectic, metal and dielectic media. Generation of LRSP has been confirmed by observing the propagation of the LRSP. Raman signal of pyridine adsorbed on the silver surface in the above layered structure has been observed and compared with the bulk Raman signal and SERS signal from the chemically adsorbed pyridine. SERS experiment by use of LRSP has not yet reported to the best of our knowledge. (Author)

The first acceleration test of polarized protons in KEK PS

International Nuclear Information System (INIS)

Hiramatsu, Shigenori; Sato, Hikaru; Toyama, Takeshi

1984-03-01

The outline of the polarized proton acceleration project at KEK and the results of the first acceleration test are described. Depolarization in the 500 MeV booster synchrotron was investigated as the first step of this program. The beam polarization was measured in the 20 MeV beam transport line from the linac to the booster and in the main ring at the injection energy. About 40 % of the linac beam polarization was kept in the main ring. This acceleration test encouraged us to proceed with this program. (author)

Copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines: synthesis of imidazopyridine derivatives.

Science.gov (United States)

Yu, Jipan; Jin, Yunhe; Zhang, Hao; Yang, Xiaobo; Fu, Hua

2013-12-02

A novel, efficient, and practical method for the synthesis of imidazopyridine derivatives has been developed through the copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines with N-(alkylidene)-4H-1,2,4-triazol-4-amines. The procedure occurs by cleavage of the N-N bond in the N-(alkylidene)-4H-1,2,4-triazol-4-amines and activation of an aryl C-H bond in the substituted pyridines. This is the first example of the preparation of imidazopyridine derivatives by using pyridines as the substrates by transition-metal-catalyzed C-H functionalization. This method should provide a novel and efficient strategy for the synthesis of other nitrogen heterocycles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Directory of Open Access Journals (Sweden)

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.

η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV

Science.gov (United States)

Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.

2010-11-01

The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.

The cross-section for J/psi production in proton-proton collisions at centre-of-mass energies between 23 and 63 GeV/c

International Nuclear Information System (INIS)

Cobb, J.H.; Iwata, S.; Palmer, R.B.; Rahm, D.C.; Stumer, I.; Fabjan, C.W.; Mannelli, I.; Nakamura, K.; Nappi, A.; Struczinski, W.; Willis, W.J.; Goldberg, M.; Horwitz, N.; Moneti, G.C.; Kourkoumelis, C.; Lankford, A.J.; Rehak, P.

1977-01-01

The cross-section for J/psi production in proton-proton collisions has been measured as a function of centre-of-mass energy at the CERN Intersecting Storage Rings by observing its decay into electron-positron pairs. This cross-section is found to rise by a factor of about six over the full centre-of mass energy range from √s=23 to √s=63 GeV. Electrons resulting from this decay were identified by the use of liquid argon calorimeters and lithium foil transition radiators. Measurements of the energies of the electrons were obtained from the liquid argon calorimeters. (Auth.)

Self-assembly behavior of poly(fluorenyl styrene)-block-poly(2-vinyl pyridine) and their blends with single wall carbon nanotubes (SWCNT)

Science.gov (United States)

Mezzenga, Raffaele; Li, Chaoxu; Hsu, Jung-Ching; Chen, Wen-Chang; Sugiyama, Kenji; Hirao, Akira

2010-03-01

We describe a supramolecular strategy to disperse carbon nanotubes in block copolymer matrices. To achieve the desired functions and morphologies, comb-type architectures in which one and two fluorene units attached on the styrene ring of polystyrene-block-poly(2-vinyl pyridine) were studied. Depending on the pendant fluorene units, the block ratio, the casting solvent and thermal annealing history, multiple morphologies were found. The phase diagram, compared to PS-b-P2VP, was interpreted in terms of the conformational asymmetry arising from grafting of fluorene units of variable lengths. Hydrogen bonds between COOH-SWCNT and P2VP favor miscibility of SWCNT within P2VP domains and the blending of these two components is reflected both on the final morphologies and on the electron conductivity of the blends.

Potentiometric and ab initio studies of acid-base interactions of substituted 4-halo(Cl, Br)pyridine N-oxide systems

Energy Technology Data Exchange (ETDEWEB)

Gurzynski, Lukasz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Makowski, Mariusz [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Makowska, Joanna [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Chmurzynski, Lech [Department of General Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)]. E-mail: lech@chem.univ.gda.pl

2006-12-15

By using the potentiometric method, acidity constants have been determined in systems of tri- and tetra-substituted pyridine N-oxides. The potentiometric measurements in systems of four 4-chloropyridine N-oxide derivatives containing the chlorine atom at position 4 to the NO{sub 2} group and four bromine counterparts were carried out in polar non-aqueous solvents, viz. amphiprotic methanol (MeOH) and aprotic protophilic dimethyl sulfoxide (DMSO). It was found that in all the systems studied the pK {sub a} values were readily determinable (as indicated by small standard deviations) in MeOH, whereas in DMSO large standard deviations were obtained making the pK {sub a} values either hardly determinable or indeterminable from potentiometric measurements. Furthermore, it was demonstrated that the acidity constants of protonated N-oxides studied in MeOH changed according to the sequence of their acidity constants in water. It was also found that in the polar solvents studied, i.e. in the amphiprotic methanol and the highly basic aprotic dimethyl sulfoxide, the cationic homo-conjugation equlibrium constants could not be determined using potentiometric method. Also, by using ab initio methods at the RHF and MP2 levels and the PCM model, utilizing the Gaussian 6-31++G** basis set, energies and Gibbs free energies of the protonation reactions of the N-oxides have been determined. The energy parameters have been compared with acidity constants of the protonated N-oxides determined by potentiometric titration in methanol to establish a correlation between these approaches.

Ray Tracing through the Edge Focusing of Rectangular Benders and an Improved Model for the Los Alamos Proton Storage Ring

Energy Technology Data Exchange (ETDEWEB)

Kolski, Jeffrey S. [Los Alamos National Laboratory; Barlow, David B. [Los Alamos National Laboratory; Macek, Robert J. [Los Alamos National Laboratory; McCrady, Rodney C. [Los Alamos National Laboratory

2011-01-01

Particle ray tracing through simulated 3D magnetic fields was executed to investigate the effective quadrupole strength of the edge focusing of the rectangular bending magnets in the Los Alamos Proton Storage Ring (PSR). The particle rays receive a kick in the edge field of the rectangular dipole. A focal length may be calculated from the particle tracking and related to the fringe field integral (FINT) model parameter. This tech note introduces the baseline lattice model of the PSR and motivates the need for an improvement in the baseline model's vertical tune prediction, which differs from measurement by .05. An improved model of the PSR is created by modifying the fringe field integral parameter to those suggested by the ray tracing investigation. This improved model is then verified against measurement at the nominal PSR operating set point and at set points far away from the nominal operating conditions. Lastly, Linear Optics from Closed Orbits (LOCO) is employed in an orbit response matrix method for model improvement to verify the quadrupole strengths of the improved model.

NMR Study of Solvation Effect on Geometry of Proton-Bound Homodimers of Increasing Size

KAUST Repository

Gurinov, Andrei A.

2017-10-24

Hydrogen bond geometries in the proton-bound homodimers of quinoline and acridine derivatives in an aprotic polar solution have been experimentally studied using 1H NMR at 120 K. The reported results show that increase of the dielec-tric permittivity of the medium results in contraction of the N…N distance. The degree of contraction depends on the homodimer\\'s size and its substituent-specific solvation features. Neither of these effects can be reproduced using conven-tional implicit solvent models employed in computational studies. In general, the N…N distance in the homodimers of pyridine, quinoline, and acridine derivatives decreases in the sequence gas phase > solid state > polar solvent.

NMR Study of Solvation Effect on Geometry of Proton-Bound Homodimers of Increasing Size

KAUST Repository

Gurinov, Andrei A.; Denisov, Gleb S.; Borissova, Alexandra O.; Goloveshkin, Alexander S.; Greindl, Julian; Limbach, Hans-Heinrich; Shenderovich, Ilya G.

2017-01-01

Hydrogen bond geometries in the proton-bound homodimers of quinoline and acridine derivatives in an aprotic polar solution have been experimentally studied using 1H NMR at 120 K. The reported results show that increase of the dielec-tric permittivity of the medium results in contraction of the N…N distance. The degree of contraction depends on the homodimer's size and its substituent-specific solvation features. Neither of these effects can be reproduced using conven-tional implicit solvent models employed in computational studies. In general, the N…N distance in the homodimers of pyridine, quinoline, and acridine derivatives decreases in the sequence gas phase > solid state > polar solvent.

Analytical solutions for the invariant spin field for model storage rings

International Nuclear Information System (INIS)

Mane, S.R.

2002-01-01

We present nonperturbative analytical expressions for the invariant spin field for several storage ring models. In particular, we solve the important models of a ring with one Snake and a single resonance driving term, and a ring with two Snakes and a single resonance driving term. We also treat several other models, all of which contain Siberian Snakes. Our solutions contain some novel features, e.g. in some cases the polarization does not point along the direction of the closed-orbit spin quantization axis. We also include vertical resonance driving terms, and consider the contributions of sextupoles and higher order multipoles to the resonance driving terms, and argue that these can play a significant role in some circumstances. We offer some brief remarks on the so-called Snake resonances. We relate our results to observations of higher-order depolarizing spin resonances for polarized proton beams in a real ring, and offer some suggestions as to how our ideas might be verified

Superconducting conversion of the Intersecting storage Rings

International Nuclear Information System (INIS)

1977-01-01

A study is presented of design, performances and cost estimates for superconducting proton storage rings in the existing ISR tunnel at CERN. By using a proven technology for the superconducting magnets an energy of 120 GeV is attainable, which corresponds to a bending field of 5.12 T. Using injection from the PS and stacking at 25 GeV, followed by phase displacement acceleration, luminosities of up to 4.10 33 cm -2 s -1 at 120 GeV are obtained. (Auth.)

Superconducting magnets for high energy storage rings

International Nuclear Information System (INIS)

Sampson, W.B.

1977-01-01

Superconducting dipole and quadrupole magnets were developed for the proton-proton intersecting storage accelerator ISABELLE. Full size prototypes of both kinds of magnets were constructed and successfully tested. The coils are fabricated from a single layer of wide braided superconductor and employ a low temperature iron core. This method of construction leads to two significant performance advantages; little or no training, and the ability of the coil to absorb its total magnetic stored energy without damage. A high pressure (15 atm) helium gas system is used for cooling. Measurements of the random field errors are compared with the expected field distribution. Three magnets (two dipoles and one quadrupole) were assembled into a segment of the accelerator ring structure (half cell). The performance of this magnet array, which is coupled in series both electrically and cryogenically, is also summarized

Final environmental impact statement. Proton--Proton Storage Accelerator Facility (ISABELLE), Brookhaven National Laboratory, Upton, New York

International Nuclear Information System (INIS)

1978-08-01

An Environmental Impact Statement for a proposed research facility (ISABELLE) to be built at Brookhaven National Laboratory (BNL) is presented. It was prepared by the Department of Energy (DOE) following guidelines issued for such analyses. In keeping with DOE policy, this statement presents a concise and issues-oriented analysis of the significant environmental effects associated with the proposed action. ISABELLE is a proposed physics research facility where beams of protons collide providing opportunities to study high energy interactions. The facility would provide two interlaced storage ring proton accelerators, each with an energy up to 400 GeV intersecting in six experimental areas. The rings are contained in a tunnel with a circumference of 3.8 km (2.3 mi). The facility will occupy 250 ha (625 acres) in the NW corner of the existing BNL site. A draft Environmental Impact Statement for this proposed facility was issued for public review and comment by DOE on February 21, 1978. The principal areas of concern expressed were in the areas of radiological impacts and preservation of cultural values. After consideration of these comments, appropriate actions were taken and the text of the statement has been amended to reflect the comments. The text was annotated to indicate the origin of the comment. The Appendices contain a glossary of terms and listings of metric prefixes and conversions and symbols and abbreviations

Properties of the electron cloud in a high-energy positron and electron storage ring

International Nuclear Information System (INIS)

Harkay, K.C.; Rosenberg, R.A.

2003-01-01

Low-energy, background electrons are ubiquitous in high-energy particle accelerators. Under certain conditions, interactions between this electron cloud and the high-energy beam can give rise to numerous effects that can seriously degrade the accelerator performance. These effects range from vacuum degradation to collective beam instabilities and emittance blowup. Although electron-cloud effects were first observed two decades ago in a few proton storage rings, they have in recent years been widely observed and intensely studied in positron and proton rings. Electron-cloud diagnostics developed at the Advanced Photon Source enabled for the first time detailed, direct characterization of the electron-cloud properties in a positron and electron storage ring. From in situ measurements of the electron flux and energy distribution at the vacuum chamber wall, electron-cloud production mechanisms and details of the beam-cloud interaction can be inferred. A significant longitudinal variation of the electron cloud is also observed, due primarily to geometrical details of the vacuum chamber. Such experimental data can be used to provide realistic limits on key input parameters in modeling efforts, leading ultimately to greater confidence in predicting electron-cloud effects in future accelerators.

Kinetics of pyridine degradation along with toluene and methylene chloride with Bacillus sp. in packed bed reactor

Energy Technology Data Exchange (ETDEWEB)

Uma, B.; Sandhya, S. [National Environmental Engineering Research Institute, CSIR-Complex, Madras (India)

1998-04-01

Bacillus coagulans strain isolated from contaminated soil was immobilised on activated carbon for degradation of pyridine, toluene and methylene chloride containing synthetic wastewaters. Pyridine was supplied as the only source of nitrogen in the wastewaters. Continuous runs in a packed bed laboratory reactor showed that immobilized B. coagulans can degrade pyridine along with other organics rapidly and the effluent ammonia is also controlled in presence of ``organic carbon``. About 644 mg/l of influent TOC was efficiently degraded (82.85%) at 64.05 mg/l/hr loading. (orig.) With 2 figs., 4 tabs., 15 refs.

One-pot, three-component synthesis of highly substituted pyridines ...

Indian Academy of Sciences (India)

Administrator

trile in the presence of nanocrystalline magnesium oxide provides the highly substituted pyridine derivatives in moderate to ..... NAP–MgO (0⋅1 g), ethanol (5 mL) at reflux temperature b ... difference in the electronic and steric properties of.

Main Ring bunch spreaders: Past, 1987/1988 fixed target run, and proposed future

International Nuclear Information System (INIS)

Jackson, G.P.

1989-01-01

During the last 1987--1988 fixed target running period beam intensity was limited many times by coherent instabilities in both the Main Ring and in the Tevatron. The intensity thresholds for instabilities are generally inversely proportional to the proton bunch length. Since fixed target operations are insensitive to the longitudinal phase space emittance of the beam, bunch spreaders are employed to increase this emittance, and hence the bunch length. As a result, more beam intensity can be delivered to the fixed target experiments. This paper starts with a short history behind the old Main Ring bunch spreader. After discussing the physics of stimulated emittance growth, the design and performance of the 1987--1988 fixed target run Main Ring bunch spreader is discussed. Finally, designs of improved Main Ring and Tevatron bunch spreaders for the next fixed target run are proposed. 23 figs

The donut and dynamic polarization effects in proton channeling through carbon nanotubes

DEFF Research Database (Denmark)

Borka, D.; Mowbray, Duncan; Miskovic, Z.L.

2010-01-01

We investigate the angular and spatial distributions of protons with an energy of 0.223 MeV after channeling them through an (11, 9) single-wall carbon nanotube of 0.2 mu m length. The proton incident angle is varied between 0 and 10 mrad, being close to the critical angle for channeling. We show...... that, as the proton incident angle increases and approaches the critical angle for channeling, a ring-like structure is developed in the angular distribution-the donut effect. We demonstrate that it is the rainbow effect. If the proton incident angle is between zero and half of the critical angle...... for channeling, the image force affects considerably the number and positions of the maxima of the angular and spatial distributions. However, if the proton incident angle is close to the critical angle for channeling, its influence on the angular and spatial distributions is considerably decreased. We...

Beam profile measurement with flying wires at the Fermilab Recycler Ring

Energy Technology Data Exchange (ETDEWEB)

Carcagno, R.; Pishchalnikov, Yu.; Krider, J.; Hu, M.; Lorman, E.; Marchionni, A.; Pordes, S.; Wilson, P.; Zagel, J.; /Fermilab

2005-05-01

Flying wires were installed at the Fermilab Recycler Ring for transverse beam profile measurement for both proton and antiproton beams. The following note describes the system configuration, calibration and resolution of the flying wire system, interactions between the wires and the beam, as well as analysis of the transverse beam profile in the presence of a stochastic cooling system.

Beam profile measurement with flying wires at the Fermilab Recycler Ring