Cortante-fricción de los hormigones reciclados

The aim of this research was to determine the behavior of recycled concrete in response to the phenomenon of shear transfer. To perform it, a conventional control concrete and a concrete with 50% recycled coarse aggregate were designed. An additional goal was to shed light on how this behavior is modified with a pozzolanic addition, silica fume. Therefore, two types of concrete were designed, a conventional and a recycled concrete, both made with 8% of silica fume. In conclusion, a reduction of shear friction capacity was observed in recycled concretes, considerably higher in the case of the specimen without reinforcement. The addition of silica fume improved the behavior of recycled concretes. The results obtained were compared with the formulations of the different authors. In all cases, these were found to be conservative. However, the safety margins offered by recycled concretes are lower than those obtained with conventional concretes.En esta investigación se estudió el comportamiento de los hormigones reciclados frente al fenómeno de transmisión de cortante. Para ello se diseñó un hormigón convencional de control y un hormigón con el 50% del árido grueso reciclado. Adicionalmente, para determinar cómo este comportamiento se ve modificado con la incorporación de una adición puzolánica (humo de sílice), se procedió al diseño de un hormigón convencional y su correspondiente reciclado con un 8% de humo de sílice. Los resultados indicaron una disminución de la capacidad frente a este fenómeno en los hormigones reciclados, más acusada en ausencia de armadura pasante. La adición de humo de sílice mejora el comportamiento de este material. Los resultados experimentales obtenidos se compararon con formulaciones teóricas de diversos autores, concluyéndose que éstas son, en todos los casos, conservadoras, aunque reducen el margen de seguridad en los hormigones reciclados

Pedigree analysis of the Spanish grapevine cultivar 'Hebén'

The use of Single Nucleotide Polymorphism (SNP) markers allows genetic identification and parentage analysis of grapevine cultivars. Ancient cultivars like 'Hebén' were widely cultivated in the Iberian Peninsula along its history and likely contributed to the origin of varieties which are still cultivated today. The goal of our study was to search for possible first-degree relationships between the female variety 'Hebén' and other Iberian and Mediterranean cultivars. For this purpose, we used a set of 261 SNP markers which allowed identifying 23 trios and 37 parent-offspring relationships supported by high overall likelihood ratios (LOD scores). The results shed light on the relationships among several cultivars from Spain and Portugal, and demonstrated that 'Hebén' is a major founder of current varieties in the Iberian Peninsula viticulture, and contributed to spread the chlorotype A in this region

Diagnóstico microscópico de piroplasmosis en caninos con presencia de garrapatas en la ciudad de Córdoba, Argentina

La piroplasmosis canina es una hemoparasitosis distribuida mundialmente y transmitida por garrapatas. Babesia vogeli es el piroplasma de mayor distribución debido a la naturaleza cosmopolita de su principal vector, la garrapata Rhipicephalus sanguineus. El uso de la microscopia a partir de frotis de sangre capilar es un método simple, accesible y de fácil implementación en la clínica diaria para el diagnóstico de piroplasmas y hemopatogenos asociados. Los objetivos de este trabajo son: a) determinar la presencia de piroplasmas en frotis sanguíneos de perros con garrapatas procedentes de la ciudad de Córdoba; b) identificar las garrapatas presentes en los casos positivos y c) establecer la presencia de coinfecciones con otros hemopatogenos transmitidos por garrapatas

The monoclinic phase of PZT ceramics: Raman and phenomenological theory studies

This work reports on the first Raman detection of the tetragonal to monoclinic phase transition in PZT ceramics near morphotropic phase boundary at low temperatures. The transition is characterized by changes in the frequency of lattice modes with the temperature. The results presented here confirm the previous one recently reported by Noheda et al. using high-resolution synchrotron X-ray powder diffraction technique and dielectric measurements. The stability of the new phase is discussed within the framework of phenomenological Landau-Devonshire Theory.Comment: 6 pages including 4 figures, Latex, submitted to Applied Physics Letter

Densificación de cerámicas de PZN-10PT a partir de polvos sintetizados por el método de reacción por combustión

((1-x)Pb(Zn1=3Nb2=3)O3-xPbTiO3-PZN-xPT) single crystals with perovskite structure near to the morphotropic phase boundary (MPB), x_0; 09, exhibit unusual large dielectric and piezoelectric constants. Preparation of PZN-PT ceramics with composition near to((1-x) Pb (Zn1 = 3Nb2 = 3) O3-xPbTiO3-PZN-xPT) monocristales con estructura de perovskita cerca del límite de la fase morfotrópica (MPB), x_0; 09, exhiben grandes constantes dieléctricas y piezoeléctricas inusuales. La preparación de cerámica PZN-PT con

Room temperature nonlinear magnetoelectric effect in lead-free and Nb-doped AlFeO3 compositions

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFUNDAÇÃO ARAUCÁRIA DE APOIO AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO ESTADO DO PARANÁ - FAPPRCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORIt is still a challenging problem to obtain technologically useful materials displaying strong magnetoelectric coupling at room temperature. In the search for new effects and materials to achieve this kind of coupling, a nonlinear magnetoelectric effect was proposed in the magnetically disordered relaxor ferroelectric materials. In this context, the aluminum iron oxide (AlFeO3), a room temperature ferroelectric relaxor and magnetic spin glass compound, emerges as an attractive lead-free magnetoelectric material along with nonlinear magnetoelectric effects. In this work, static, dynamic, and temperature dependent ferroic and magnetoelectric properties in lead-free AlFeO3 and 2 at. Nb-doped AlFeO3 multiferroic magnetoelectric compositions are studied. Pyroelectric and magnetic measurements show changes in ferroelectric and magnetic states close to each other (∼200 K). The magnetoelectric coefficient behavior as a function of Hbias suggests a room temperature nonlinear magnetoelectric coupling in both single-phase and Nb-doped AlFeO3-based ceramic compositions.It is still a challenging problem to obtain technologically useful materials displaying strong magnetoelectric coupling at room temperature. In the search for new effects and materials to achieve this kind of coupling, a nonlinear magnetoelectric effect was proposed in the magnetically disordered relaxor ferroelectric materials. In this context, the aluminum iron oxide ( AlFeO3), a room temperature ferroelectric relaxor and magnetic spin glass compound, emerges as an attractive lead-free magnetoelectric material along with nonlinear magnetoelectric effects. In this work, static, dynamic, and temperature dependent ferroic and magnetoelectric properties in lead-free AlFeO3 and 2 at.% Nb-doped AlFeO3 multiferroic magnetoelectric compositions are studied. Pyroelectric and magnetic measurements show changes in ferroelectric and magnetic states close to each other ( similar to 200 K). The magnetoelectric coefficient behavior as a function of Hbias suggests a room temperature nonlinear magnetoelectric coupling in both single-phase and Nb-doped AlFeO3-based ceramic compositions.117617CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFUNDAÇÃO ARAUCÁRIA DE APOIO AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO ESTADO DO PARANÁ - FAPPRCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFUNDAÇÃO ARAUCÁRIA DE APOIO AO DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO DO ESTADO DO PARANÁ - FAPPRCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR305129/2010-42008/04025-022825, 22870082/2007Hill, N.A., (2000) J. Phys. Chem. B, 104, p. 6694Ueda, K., Tabata, H., Kawai, T., (1999) Appl. Phys. Lett., 75, p. 555Kumar, M.M., Suresh, M.B., Suryanarayana, S.V., Kumar, G.S., Bhimasankaram, T., (1998) J. Appl. Phys., 84, p. 6811Dzyaloshinskii, I.E., Pitaevskii, L.P., (1959) Sov. Phys. JETP - USSR, 9, p. 1282Fiebig, M., (2005) J. Phys. D: Appl. Phys., 38, p. R123Freitas, V.F., Cotica, L.F., Santos, I.A., Garcia, D., Eiras, J.A., (2011) J. Eur. Ceram. Soc., 31, p. 2965Cotica, L.F., Estrada, F.R., Freitas, V.F., Dias, G.S., Santos, I.A., Eiras, J.A., Garcia, D., (2012) J. Appl. Phys., 111Gotardo, R.A.M., Cotica, L.F., Santos, I.A., Olzon-Dyonisio, M., Souza, S.D., Garcia, D., Eiras, J.A., Coelho, A.A., (2013) Appl. Phys. A: Mater. Sci. Process., 111, p. 563Lee, J.H., Fang, L., Vlahos, E., Ke, X.L., Jung, Y.W., Kourkoutis, L.F., Kim, J.W., Schlom, D.G., (2010) Nature, 466, p. 954Lorenz, B., Wang, Y.Q., Sun, Y.Y., Chu, C.W., (2004) Phys. Rev. B, 70Abe, N., Taniguchi, K., Ohtani, S., Umetsu, H., Arima, T., (2009) Phys. Rev. B, 80Kundys, B., Simon, C., Martin, C., (2008) Phys. Rev. B, 77Palkar, V.R., Purandare, S.C., Gohil, S., John, J., Bhattacharya, S., (2007) Appl. Phys. Lett., 90Kumar, A., Rivera, I., Katiyar, R.S., Scott, J.F., (2008) Appl. Phys. Lett., 92Pirc, R., Blinc, R., (2010) Ferroelectrics, 400, p. 387Cross, L.E., (1987) Ferroelectrics, 76, p. 241Dho, J., Kim, W.S., Hur, N.H., (2002) Phys. Rev. Lett., 89Cotica, L.F., De Medeiros, S.N., Santos, I.A., Paesano, A., Kinast, E.J., Da Cunha, J.B.M., Venet, M., Eiras, J.A., (2006) Ferroelectrics, 338, p. 241Devaux, X., Rousset, A., Broto, J.M., Rakoto, H., Askenazy, S., (1990) J. Mater. Sci. Lett., 9, p. 371Cotica, L.F., Santos, I.A., Venet, M., Garcia, D., Eiras, J.A., Coelho, A.A., (2008) Solid State Commun., 147, p. 123Santos, G.M., Silva, D.M., Freitas, V.F., Dias, G.S., Coelho, A.A., Pal, M., Santos, I.A., Bhalla, A.S., (2014) Ferroelectrics, 460, p. 108Bouree, F., Baudour, J.L., Elbadraoui, E., Musso, J., Laurent, C., Rousset, A., (1996) Acta Crystallogr., Sect. B: Struct. Sci., 52, p. 217Saha, R., Shireen, A., Shirodkar, S.N., Waghmare, U.V., Sundaresan, A., Rao, C.N.R., (2012) Solid State Commun., 152, p. 1964Shen, Y., Gao, J., Wang, Y., Finkel, P., Li, J., Viehland, D., (2013) Appl. Phys. Lett., 102Pirc, R., Blinc, R., (2009) Phys. Rev. B, 79Cotica, L.F., Zanatta, S.C., De Medeiros, S.N., Dos Santos, I.A., Paesano, A., Da Cunha, J.B.M., (2004) Solid State Ionics, 171, p. 283Yang, Y., Íñiguez, J., Mao, A.-J., Bellaiche, L., (2014) Phys. Rev. Lett., 112The authors would like to thank the Brazilian agencies CNPq (proc. 305129/2010-4), FAPESP (proc. 2008/04025-0), Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Paraná (Prots. 22825 and 22870), and CAPES (PROCAD 082/2007) for financial support. L.F.C. also acknowledge UTSA under the INAMM/NSF program for hosting him

Bˉ→Xsγ\bar{B}\to X_s \gamma in the Two Higgs Doublet Model up to Next-to-Next-to-Leading Order in QCD

We compute three-loop matching corrections to the Wilson coefficients $C_7$ and $C_8$ in the Two Higgs Doublet Model by applying expansions for small, intermediate and large charged Higgs boson masses. The results are used to evaluate the branching ratio of $\bar{B}\to X_s \gamma$ to next-to-next-to leading order accuracy, and to determine an updated lower limit on the charged Higgs boson mass. We find \mhplus \ge 380 GeV at 95% confidence level when the recently completed BABAR data analysis is taken into account. Our results for the charged Higgs contribution to the branching ratio exhibit considerably weaker sensitivity to the matching scale $\mu_0$, as compared to previous calculations.Comment: 20 pages, 15 figures; v2: minor modifications, matches published version in JHE

Energy and decay width of the pi-K atom

The energy and decay width of the pi-K atom are evaluated in the framework of the quasipotential-constraint theory approach. The main electromagnetic and isospin symmetry breaking corrections to the lowest-order formulas for the energy shift from the Coulomb binding energy and for the decay width are calculated. They are estimated to be of the order of a few per cent. We display formulas to extract the strong interaction S-wave pi-K scattering lengths from future experimental data concerning the pi-K atom.Comment: 37 pages, 5 figures, uses Axodra