2,169 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Threading/dethreading processes in pseudorotaxanes. A thermodynamic and kinetic study
No full textPseudorotaxanes are host-guest complexes made of a thread-like component penetrating a bead-like component. We have investigated, by a stopped-flow technique, the threading/dethreading kinetics of pseudorotaxanes formed between a tetracationic cyclophane, cyclobis(paraquat-p-phenylene), and thread-like compounds consisting of a naphthalene ring system with appended -(OCH 2CH2)nOH groups (n from 0 to 3) on the 1 and 5 positions. The association and rate constants have been measured in MeCN (from 276 to 293 K) and H2O (from 276 to 313 K). In MeCN solution, the association constant increases with increasing length of the appended chain (e.g., Kass = 1.0 × 103 M-1 for n = 0 and Kass = 4.0 × 104 M-1 for n = 3, at 293 K); in H2O, the association constants are larger than in MeCN, but almost independent of the chain length. Both the threading (kt) and dethreading (kd) rate constants are larger in MeCN than in H 2O and decrease with increasing chain length (e.g., kt > 108 and kt = 4 × 106 M-1 s-1 for n = 0 and n = 3, respectively, in H2O at 276 K). Thermodynamic and kinetic parameters have been obtained and the role played by the length of the chains appended to the naphthalene ring system is discussed.link_to_subscribed_fulltex
Fabrieksschema betreffende de "Bereiding van Magnesium uit Zeewater": Deel I
No full textDocument(en) uit de collectie Chemische Procestechnologie Deel II zie: Deeg, J.F., Chemical Process Design 1101DelftChemTechApplied Science
Beatty, J.F., and the Law of Manslaughter
Get PDFIn this article, the author argues that the recent Supreme Court of Canada decisions in R. v. Beatty and R. v. J.F. have clarified several of the issues that have plagued the increasingly complicated offence of manslaughter. In particular, the decisions address the redundancy among the many manslaughter provisions in the Criminal Code, the need to define a clear separation between actus reus and mens rea, and the need to establish distinct categories of objective fault for different types of manslaughter offences. The author examines the legal background of these decisions as well as the current state of the law. He concludes by identifying emerging issues relating to the offence of manslaughter, arguing that the law remains convoluted and in need of urgent reform despite the progress made in the Beatty and J.F. decisions
Autonomous Artificial Nanomotor Powered by Sunlight
Get PDFLight excitation powers the reversible shuttling movement of the ring component of a rotaxane between two stations located at a 1.3-nm distance on its dumbbell-shaped component. The photoinduced shuttling movement, which occurs in solution, is based on a "four-stroke" synchronized sequence of electronic and nuclear processes. At room temperature the deactivation time of the high-energy charge-transfer state obtained by light excitation is approximate to 10 mu s, and the time period required for the ring-displacement process is on the order of 100. mu s. The rotaxane behaves as an autonomous linear motor and operates with a quantum efficiency up to approximate to 12%. The investigated system is a unique example of an artificial linear nanomotor because it gathers together the following features: (i) it is powered by visible light (e.g., sunlight); (h) it exhibits autonomous behavior, like motor proteins; (iii) it does not generate waste products; (iv) its operation can rely only on intramolecular processes, allowing in principle operation at the single-molecule level; (v) it can be driven at a frequency of 1 kHz; (vi) it works in mild environmental conditions (i.e., fluid solution at ambient temperature); and (vii) it is stable for at least 10(3) cycles.Balzani, V.; Clemente-Leon, M.; Credi, A.; Ferrer Ribera, RB.; Venturi, M.; Flood, A.; Stoddart, J. (2006). Autonomous artificial nanomotor powered by sunlight. Proceedings of the National Academy of Sciences. 103(5):1178-1183. doi:10.1073/pnas.0509011103S117811831035Balzani, V., Credi, A., Raymo, F. M., & Stoddart, J. F. (2000). Artificial Molecular Machines. Angewandte Chemie, 39(19), 3348-3391. doi:10.1002/1521-3773(20001002)39:193.0.co;2-xMolecular Machines Special Issue. (2001). Accounts of Chemical Research, 34(6), 409-409. doi:10.1021/ar0100881Joachim, C., & Gimzewski, J. K. (s. f.). Single Molecular Rotor at the Nanoscale. Structure and Bonding, 1-18. doi:10.1007/3-540-44421-1_1Balzani, V., Credi, A., Ferrer, B., Silvi, S., & Venturi, M. (s. f.). Artificial Molecular Motors and Machines: Design Principles and Prototype Systems. Topics in Current Chemistry, 1-27. doi:10.1007/128_008Oster, G., & Wang, H. (2003). Rotary protein motors. Trends in Cell Biology, 13(3), 114-121. doi:10.1016/s0962-8924(03)00004-7Lehn, J.-M. (2002). Toward complex matter: Supramolecular chemistry and self-organization. Proceedings of the National Academy of Sciences, 99(8), 4763-4768. doi:10.1073/pnas.072065599Steinberg-Yfrach, G., Rigaud, J.-L., Durantini, E. N., Moore, A. L., Gust, D., & Moore, T. A. (1998). Light-driven production of ATP catalysed by F0F1-ATP synthase in an artificial photosynthetic membrane. Nature, 392(6675), 479-482. doi:10.1038/33116Kelly, T. R., De Silva, H., & Silva, R. A. (1999). Unidirectional rotary motion in a molecular system. Nature, 401(6749), 150-152. doi:10.1038/43639Koumura, N., Zijlstra, R. W. J., van Delden, R. A., Harada, N., & Feringa, B. L. (1999). Light-driven monodirectional molecular rotor. Nature, 401(6749), 152-155. doi:10.1038/43646Brouwer, A. M. (2001). Photoinduction of Fast, Reversible Translational Motion in a Hydrogen-Bonded Molecular Shuttle. Science, 291(5511), 2124-2128. doi:10.1126/science.1057886Badjic, J. D. (2004). A Molecular Elevator. Science, 303(5665), 1845-1849. doi:10.1126/science.1094791Hernandez, J. V. (2004). A Reversible Synthetic Rotary Molecular Motor. Science, 306(5701), 1532-1537. doi:10.1126/science.1103949Mobian, P., Kern, J.-M., & Sauvage, J.-P. (2004). Light-Driven Machine Prototypes Based on Dissociative Excited States: Photoinduced Decoordination and Thermal Recoordination of a Ring in a Ruthenium(II)-Containing[2]Catenane. Angewandte Chemie International Edition, 43(18), 2392-2395. doi:10.1002/anie.200352522Sherman, W. B., & Seeman, N. C. (2004). A Precisely Controlled DNA Biped Walking Device. Nano Letters, 4(7), 1203-1207. doi:10.1021/nl049527qAstumian, R. D. (2005). Chemical peristalsis. Proceedings of the National Academy of Sciences, 102(6), 1843-1847. doi:10.1073/pnas.0409341102Zheng, X., Mulcahy, M. E., Horinek, D., Galeotti, F., Magnera, T. F., & Michl, J. (2004). Dipolar and Nonpolar Altitudinal Molecular Rotors Mounted on an Au(111) Surface. Journal of the American Chemical Society, 126(14), 4540-4542. doi:10.1021/ja039482fKatz, E., Lioubashevsky, O., & Willner, I. (2004). Electromechanics of a Redox-Active Rotaxane in a Monolayer Assembly on an Electrode. Journal of the American Chemical Society, 126(47), 15520-15532. doi:10.1021/ja045465uVan Delden, R. A., ter Wiel, M. K. J., Pollard, M. M., Vicario, J., Koumura, N., & Feringa, B. L. (2005). Unidirectional molecular motor on a gold surface. Nature, 437(7063), 1337-1340. doi:10.1038/nature04127Liu, Y., Flood, A. H., Bonvallet, P. A., Vignon, S. A., Northrop, B. H., Tseng, H.-R., … Stoddart, J. F. (2005). Linear Artificial Molecular Muscles. Journal of the American Chemical Society, 127(27), 9745-9759. doi:10.1021/ja051088pNguyen, T. D., Tseng, H.-R., Celestre, P. C., Flood, A. H., Liu, Y., Stoddart, J. F., & Zink, J. I. (2005). A reversible molecular valve. Proceedings of the National Academy of Sciences, 102(29), 10029-10034. doi:10.1073/pnas.0504109102Berná, J., Leigh, D. A., Lubomska, M., Mendoza, S. M., Pérez, E. M., Rudolf, P., … Zerbetto, F. (2005). Macroscopic transport by synthetic molecular machines. Nature Materials, 4(9), 704-710. doi:10.1038/nmat1455Tian, Y., & Mao, C. (2004). Molecular Gears: A Pair of DNA Circles Continuously Rolls against Each Other. Journal of the American Chemical Society, 126(37), 11410-11411. doi:10.1021/ja046507hAshton, P. R., Ballardini, R., Balzani, V., Credi, A., Dress, K. R., Ishow, E., … Wenger, S. (2000). Chemistry - A European Journal, 6(19), 3558-3574. doi:10.1002/1521-3765(20001002)6:193.0.co;2-
Unravelling the Shuttling Mechanism in a Photoswitchable Multicomponent Bistable Rotaxane
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Bouwen aan de delta: Gerealiseerde waterbouwkundige werken, Inzendingen prof. dr. ir. J.F. Agemaprijs 2015
No full textDe afgelopen jaren (2010 - 2015) zijn er in Nederland vele in het oog springende waterbouwkundige projecten gerealiseerd. Aansprekende voorbeelden betreffen onder meer Maasvlakte 2, de Zandmotor, de ontpoldering van de Noordwaard en de omlegging van de Zuid-Willemsvaart. Ook in de lokale watersystemen zijn diverse interessante projecten gebouwd. Veel van deze projecten hebben zich aangemeld voor de prof. dr. ir. J.F. Agemaprijs, dé prijs voor het beste en meest innovatieve waterbouwkundige project dat daadwerkelijk gebouwd is. Dit boek toont foto’s en projectinformatie, en bevat achtergrondinformatie over de Agemaprijs en essays van experts. De verschillende projecten geven een fraai beeld van de veelzijdigheid en innovativiteit van de Nederlandse (water)bouwers. Het boek geeft inzicht in de huidige en toekomstige manier waarop deltagebieden kunnen worden ingericht.Delft University of Technolog
On the equilibrium configuration of the BC-type ruijsenaars-Schneider system
No full textVan Diejen, J.F. (reprint author). Instituto de Matemática y Física, Universidad de Talca, Casilla 747, Talca, Chile.It is shown that the ground-state equilibrium configurations of the trigonometric BC-type Ruijsenaars-Schneider systems are given by the zeros of Askey-Wilson polynomial
Australian author Dale Collins with wife Aileen and another man onboard the Ellerman and Bucknall steamer City of Delhi, New South Wales, 7 December 1929 [picture].
No full textTitle devised from accompanying information where available.; Part of the: Fairfax archive of glass plate negatives.; Fairfax number: 5866.; Full name: Cuthbert Quinlan Dale Collins; Also available online at: http://nla.gov.au/nla.pic-vn6256859; Acquired from Fairfax Media, 2012
La Fete. Marche de Brayoure.
No full textsectionalpianoTo Joseph P. Shawads on back cover for J.F. Shaw stockJohns Hopkins University, Levy Sheet Music Collection, Box
180, Item 034par Edgar H. Sherwood.as performed by the Author at the Opening of Shaw's New Music Rooms, Rochester, N.Y.C.F. Muntz & Co. Lith. Rochester N.Y
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