Three-dimensional limit analysis of rigid blocks assemblages. Part II : load-path following solution procedure and validation

A novel solution procedure for the non-associated limit analysis of rigid blocks assemblages is proposed. This proposal produces better solutions than previously proposed procedures and it is also able to provide an insight into the structural behaviour prior to failure. The limit analysis model proposed in Part I of this paper and the solution procedure are validated through illustrative examples in three-dimensional masonry piers and walls. The use of limit analysis for three-dimensional problems incorporating non-associated flow rules and a coupled yield surface is novel in the literature

Plastic torsion on frictional joints and three-dimensional limit analysis of masonry structures

The plastic torsion of arbitrarily shaped, frictional joints is established together with its interactions with bending moments and shear forces. In order to solve limit analysis problems, a piecewise linear approximation of the yield function for rectangular joints is proposed. The proposal is incorporated into a model for limit analysis of masonry structures regarded as rigid block assemblages interacting through no tension, frictional joints. An example validates the proposal.Consejo Nacional de Ciencia y Tecnología of Mexico. Fundação para a Ciência e e Tecnologia (FCT) - Project SAPIENS 33935-99

A bivariate return period based on copulas for hydrologic dam design: accounting for reservoir routing in risk estimation

A multivariate analysis on flood variables is needed to design some hydraulic structures like dams, as the complexity of the routing process in a reservoir requires a representation of the full hydrograph. In this work, a bivariate copula model was used to obtain the bivariate joint distribution of flood peak and volume, in order to know the probability of occurrence of a given inflow hydrograph. However, the risk of dam overtopping is given by the maximum water elevation reached during the routing process, which depends on the hydrograph variables, the reservoir volume and the spillway crest length. Consequently, an additional bivariate return period, the so-called routed return period, was defined in terms of risk of dam overtopping based on this maximum water elevation obtained after routing the inflow hydrographs. The theoretical return periods, which give the probability of occurrence of a hydrograph prior to accounting for the reservoir routing, were compared with the routed return period, as in both cases hydrographs with the same probability will draw a curve in the peak-volume space. The procedure was applied to the case study of the Santillana reservoir in Spain. Different reservoir volumes and spillway lengths were considered to investigate the influence of the dam and reservoir characteristics on the results. The methodology improves the estimation of the Design Flood Hydrograph and can be applied to assess the risk of dam overtoppin

Dry joint stone masonry walls subjected to in-plane combined loading

The paper presents the results of experimental research on the structural behavior of dry joint masonry. The most relevant experimental results concern the strength response of stone dry joint masonry walls subjected to in-plane combined compressive and shear loading. Significant features of the structural behavior shown by the walls are discussed and conclusions on their ultimate capacity and observed failure mechanisms are addressed. Complementarily, the application of an existing numerical model, stemming from plasticity and based on a micromodeling strategy, is also presented and discussed with regard to its capacity to simulate the obtained experimental results. The model was calibrated with data collected from complementary tests carried out on specimens and prisms made of the same type of stone. Finally, the usage of a simplified method of analysis based on a continuum of diagonal struts is also addressed

Effect of radar rainfall time resolution on the predictive capability of a distributed hydrologic model

The performance of distributed hydrological models depends on the resolution, both spatial and temporal, of the rainfall surface data introduced. The estimation of quantitative precipitation from meteorological radar or satellite can improve hydrological model results, thanks to an indirect estimation at higher spatial and temporal resolution. In this work, composed radar data from a network of three C-band radars, with 6-minutal temporal and 2 × 2 km2 spatial resolution, provided by the Catalan Meteorological Service, is used to feed the RIBS distributed hydrological model. A Window Probability Matching Method (gage-adjustment method) is applied to four cases of heavy rainfall to improve the observed rainfall sub-estimation in both convective and stratiform Z/R relations used over Catalonia. Once the rainfall field has been adequately obtained, an advection correction, based on cross-correlation between two consecutive images, was introduced to get several time resolutions from 1 min to 30 min. Each different resolution is treated as an independent event, resulting in a probable range of input rainfall data. This ensemble of rainfall data is used, together with other sources of uncertainty, such as the initial basin state or the accuracy of discharge measurements, to calibrate the RIBS model using probabilistic methodology. A sensitivity analysis of time resolutions was implemented by comparing the various results with real values from stream-flow measurement stations

Google Scholar Metrics evolution: an analysis according to languages

The final publication is available at Springer via http://dx.doi.org/10.1007/s11192-013-1164-8In November 2012 the Google Scholar Metrics (GSM) journal rankings were updated, making it possible to compare bibliometric indicators in the ten languages indexed—and their stability—with the April 2012 version. The h-index and h-5 median of 1,000 journals were analysed, comparing their averages, maximum and minimum values and the correlation coefficient within rankings. The bibliometric figures grew significantly. In just seven and a half months the h-index of the journals increased by 15 % and the median h-index by 17 %. This growth was observed for all the bibliometric indicators analysed and for practically every journal. However, we found significant differences in growth rates depending on the language in which the journal is published. Moreover, the journal rankings seem to be stable between April and November, reinforcing the credibility of the data held by Google Scholar and the reliability of the GSM journal rankings, despite the uncontrolled growth of Google Scholar. Based on the findings of this study we suggest, firstly, that Google should upgrade its rankings at least semi-annually and, secondly, that the results should be displayed in each ranking proportionally to the number of journals indexed by language.Orduña Malea, E.; Delgado López-Cózar, E. (2014). Google Scholar Metrics evolution: an analysis according to languages. Scientometrics. 98(3):2353-2367. doi:10.1007/s11192-013-1164-8S23532367983Aguillo, & Isidro, F. (2012). Is Google Scholar useful for bibliometrics? A webometric analysis. Scientometrics, 91(2), 343–351.Brewington, B. E., & Cybenko, G. (2000). How dynamic is the Web? Computer Networks, 33(1–6), 257–276.Chen, X. (2010). Google Scholar’s dramatic coverage improvement five years after debut. Serials Review, 36(4), 221–226.Cho, Y. & Garcia-Molina, H. (2000). The evolution of the web and implications for an incremental crawler. Proceedings of the 26th International Conference on very large data bases, 200–209.Costas, R., & Bordons, M. (2007). The h-index: advantages, limitations and its relation with other bibliometric indicators at the micro level. Journal of Informetrics, 1(3), 193–203.de Winter, J. C. F., Zadpoor, A. A., & Dodou, D. (2013). The expansion of Google Scholar versus Web of Science: a longitudinal study. Scientometrics. doi: 10.1007/s11192-013-1089-2 .Delgado López-Cózar, E., & Cabezas-Clavijo, A. (2012). Google Scholar Metrics: an unreliable tool for assessing scientific journals. El profesional de la información, 21(4), 419–427.Delgado López-Cózar, E., & Cabezas-Clavijo, A. (2013). Ranking journals: could Google Scholar metrics be an alternative to journal citation reports and Scimago journal ranks. Learned publishing, 26(2), 101–114.Fetterly, D., Manasse, M., Najork, M. & Wiener, J. (2003). A large scale study of the evolution of web pages. Proceedings of the Twelfth International Conference on World Wide Web, 669–678.Harzing, A.-W. (2013). A preliminary test of Google Scholar as a source for citation data: a longitudinal study of Nobel prize winners. Scientometrics, 94(3), 1057–1075.Jacsó, P. (2012). Google Scholar Metrics for Publications—The software and content feature of a new open access bibliometric service. Online Information Review, 36(4), 604–619.Koehler, W. (2002). Web page change and persistence-4-year longitudinal web study. Journal of the American Society for Information Science and Technology, 53(2), 162–171.Koehler, W (2004). A longitudinal study of Web pages continued a consideration of document persistence. Information Research, 9(2). http://informationr.net/ir/9-2/paper174.html . Accessed 1 Sep 2013.Kousha, K., & Thelwall, M. (2007). Google Scholar Citations and Google Web/URL citations: a multidiscipline exploratory analysis. Journal of the American Society for Information Science and Technology, 58(7), 1055–1065.Leydesdorff, L. (2012). World shares of publications of the USA, EU-27, and China compared and predicted using the new Web of Science interface versus Scopus. El profesional de la información, 21(1), 43–49.Neuhaus, C., Neuhaus, E., Asher, A., & Wrede, C. (2006). The depth and breadth of Google Scholar: An empirical study. Libraries and the Academy, 6(2), 127–141.Orduña-Malea, E., Serrano-Cobos, J., & Lloret-Romero, N. (2009). Las universidades públicas españolas en Google Scholar: presencia y evolución de su publicación académica web. El profesional de la información, 18(5), 493–500.Orduña-Malea, E., Serrano-Cobos, J., Ontalba-Ruipérez, J.-A., & Lloret-Romero, N. (2010). Presencia y visibilidad web de las universidades públicas españolas. Revista española de documentación científica, 33(2), 246–278.Ortega, J. L., Aguillo, I. F., & Prieto, J. A. (2006). Longitudinal study of contents and elements in the scientific Web environment. Journal of Information Science, 32(4), 344–351.Payne, N., & Thelwall, M. (2007). A longitudinal study of academic webs: growth and stabilization. Scientometrics, 71(3), 523–539

Dinuclear pyridine-4-thiolate-bridged rhodium and iridium complexes as ditopic building blocks in molecular architecture

A series of dinuclear pyridine-4-thiolate (4-Spy)-bridged rhodium and iridium compounds [M(μ-4-Spy)(diolef)]2 [diolef = 1,5-cyclooctadiene (cod), M = Rh (1), Ir (2); diolef = 2,5-norbornadiene (nbd), M = Rh (3)] were prepared by the reaction of Li(4-Spy) with the appropriate compound [M(μ-Cl)(diolef)]2 (M = Rh, Ir). The dinuclear compound [Rh(μ-4-Spy)(CO)(PPh3)]2 (4) was obtained by the reaction of [Rh(acac)(CO)(PPh3)] (acac = acetylacetonate) with 4-pySH. Compounds 1-4 were assessed as metalloligands in self-assembly reactions with the cis-blocked acceptors [M(cod)(NCCH3)2](BF 4) [M = Rh (a), Ir (b)] and [M(H2O)2(dppp)] (OTf)2 [M = Pd (c), Pt (d); dppp = 1,3-bis(diphenylphosphino)propane] . The homometallic hexanuclear metallomacrocycles [{M2(μ-4-Spy) 2(cod)2}2{M(cod)}2](BF 4)2 (M = Rh [(1a)2], Ir [(2b)2]) and the heterometallic hexanuclear metallomacrocycles [{Rh2(μ-4-Spy) 2(cod)2}2{Ir(cod)}2](BF 4)2 [(1b)2], [{Rh2(μ-4-Spy) 2(cod)2}2{M′(dppp)}2](OTf) 4 (M′ = Pd [(1c)2], Pt [(1d)2]), and [{Ir2(μ-4-Spy)2(cod)2}2{M′ (dppp)}2](OTf)4 (M′ = Pd [(2c)2], Pt [(2d)2]) were obtained. NMR spectroscopy in combination with electrospray ionization mass spectrometry was used to elucidate the nature of the metalloligands and their respective supramolecular assemblies. Most of the synthesized species were found to be nonrigid in solution, and their fluxional behavior was studied by variable-temperature 1H NMR spectroscopy. An X-ray diffraction study of the assemblies (1a)2 and (1d)2 revealed the formation of rectangular (9.6 Å × 6.6 Å) hexanuclear metallomacrocycles with alternating dinuclear (Rh2) and mononuclear (Rh or Pt) corners. The hexanuclear core is supported by four pyridine-4-thiolate linkers, which are bonded through the thiolate moieties to the dinuclear rhodium units, exhibiting a bent-anti arrangement, and through the peripheral pyridinic nitrogen atoms to the mononuclear corners.Financial support for this work was provided by the Ministerio de Economía y Competitividad (MINECO/FEDER) of Spain (Projects CTQ2010-15221 and CTQ2012-31335), Diputación General de Aragón (Group E07), and Fondo Social Europeo.Peer Reviewe

Nature s Top 100 Re-Revisited

"This is the peer reviewed version of the following article: Martín-Martín, A., Ayllon, J. M., López-Cózar, E. D., & Orduna-Malea, E. (2015). Nature's top 100 Re-revisited. JASIST, 66(12), 2714., which has been published in final form at http://doi.org/10.1002/asi.23570. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."To mark the 50th anniversary of the Science Citation Index, Nature published a list of the 100 most-cited papers of all time. It also included an alternative ranking from data provided by Google Scholar, which, as this letter illustrates, contains certain inconsistencies. This does not, however, diminish the usefulness of Google Scholar, not only in identifying the most-cited articles of all time, but also in reflecting the impact of other document types (especially books), thus redefining the concept of academic impact. Keywords:Martín-Martín, A.; Ayllón, JM.; Delgado López-Cózar, E.; Orduña Malea, E. (2015). Nature s Top 100 Re-Revisited. Journal of the American Society for Information Science and Technology. 66(12):2714-2714. doi:10.1002/asi.23570271427146612Bornmann , L. Nature's top 100 revisited. Journal of the Association for Information Science and Technology http://www.lutz-bornmann.de/icons/top_100.pdfGarfield , E. 2005 The agony and the ecstasy-the history and meaning of the Journal Impact Factor http://www.garfield.library.upenn.edu/papers/jifchicago2005.pdfMartin-Martin , A. Orduna-Malea , E. Ayllon , J.M. Delgado Lopez-Cozar , E. 2014 Does Google Scholar contain all highly cited documents (1950-2013)? http://arxiv.org/abs/1410.8464Van Noorden, R., Maher, B., & Nuzzo, R. (2014). The top 100 papers. Nature, 514(7524), 550-553. doi:10.1038/514550