CO-PrOx over nano-Au/TiO2: Monolithic catalyst performance and empirical kinetic model fitting

In this work, the performance of ceramic monoliths washcoated with Au/TiO2 is studied on CO preferential oxidation (CO-PrOx) reaction in H2-rich environments under a wide range of operating conditions of practical interest. The parameter estimation of a nonlinear kinetic empirical model representing this system is made via genetic algorithms by fitting the model predictions against our laboratory observations. Parameter uncertainty leading to inaccurate predictions is often present when kinetic models with nonlinear rate equations are considered. Here, after the fitting was concluded, a statistical study was conducted to determine the accuracy of the parameter estimation. Activation energies of ca. 30 kJ/mol and 55 kJ/mol were adjusted for CO and H2 oxidations, respectively. The catalyst showed appropriate activity and selectivity values on the CO oxidation on a H2-rich environment. After ca. 45 h on stream the catalyst showed no deactivation. Results show that the model is suitable for reproducing the behavior of the CO-PrOx reactions and it can be used in the design of reactors for hydrogen purification.Peer ReviewedPostprint (author's final draft

Quinoidization of regioregular oligo(THIENO[3,4-b]THIOPHENE)s

Caracterización de oligotiofenosUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Evaluation of new multiaxial damage parameters on low carbon steel

Most mechanical components are subjected to the complex fatigue loading conditions, where both amplitude and direction of loading cycles change over the time. The estimation of damage caused by these complex loading scenarios are often done by simplified uniaxial fatigue theories, which ultimately leads to higher factor of safety during the final design considerations. Critical plane-based fatigue theories have been considered more accurate for computing the fatigue damage for multiaxial loading conditions in comparison to energy-based and equivalent stress-based theories. Two recently developed fatigue theories have been evaluated in this work for the available test data. Test data includes significant amount of biaxial load paths

Cryptic homoelogy analysis in species and hybrids of genus Zea

Cryptic intergenomic pairing of genus Zea was induced by the use of a diluted colchicine solution in order to elucidate the phylogenetic relations and differentiation of the homoeologous genomes. Results indicate that in species and hybrids with 2n = 20, there was chromosome pairing between the homoeologous A and B genomes with a maximum of 5IV, with the exception of Zea diploperennis and their interspecific hybrids where cryptic homoeologous chromosome pairing was not induced. In almost all 2n = 30 hybrids, observed cryptic pairing increased to a maximum of 10III although Z. mays x Z. mays with 2n = 30 did not show significant differences between treated and untreated materials. Pairing was also observed in species and hybrids with 2n = 40, in which a maximum of 10IV was observed, with the exception of Z. mays with 2n = 40 where treated and untreated cells did not differ significantly.This research was supported by the Universidad Nacional de la Plata, Universidad Nacional de Lomas de Zamora and CONICET.Molina, M.; Lopez, C.; Staltari, S.; Chorzempa, S.; Moreno Ferrero, V. (2013). Cryptic homoelogy analysis in species and hybrids of genus Zea. Biologia Plantarum. 57(3):449-456. doi:10.1007/s10535-012-0299-4S449456573Bass, H.W., Riera-Lizarazu, O., Ananiev, E.V.B., Bordolini, S.J., Rines, H.W., Phillips, R.L., Sedat, J.W., Agard, D.A., Cande, Z.W.: Evidence for the coincident initiation of homologous pairing and synapsis during the telomereclustering (bouquet) stage of meiotic prophase. — J. Cell Sci. 113: 1033–1042, 2000.Bozza, C.G., Pawlowsky, W.P.: The cytogenetics of homologous chromosome pairing in meiosis in plants. — Cytogenet. Genet. Res. 120: 313–319, 2008.Chikashige, Y., Haraguchi, T., Hiraoka, Y.: Nuclear envelope attachment is not necessary for telomere function in fission yeast. — Nucleus 1: 481–486, 2010.Dobley, J., Iltis, H.H.: Taxonomy of Zea (Gramineae). I. A subgeneric classification with key to taxa. — Amer. J. Bot. 67: 982–993, 1980.Dover, G.A., Riley, R.: The effect of spindle inhibitors applied before meiosis on meiotic chromosome pairing. — J. Cell. Sci. 12: 143–161, 1973.Driscoll, C.J., Darvey, N.L.: Chromosome pairing: effect of colchicine on an isochromosome. — Science 169: 290–291, 1970.Driscoll, C.J., Darvey, N.L., Barber, H.N.: Effect of colchicine on meiosis of hexaploid wheat. — Nature 216: 687–688, 1967.Feldman, M., Avivi, L.: Genetic control of bivalent pairing in common wheat. The mode of Ph1 action. — In: Brandham, P.E. (ed.) Kew Chromosome Conference III. Pp. 269–279. Royal Botanic Garden, London 1988.Feldman, F., Liu, B., Segal, G., Abbo, S., Levy. A.: Rapid elimination of low copy DNA sequences in polyploidy wheat: a possible mechanism for differentiation of homeologous chromosomes. — Genetics 147: 1381–1387, 1997.Fukunaga, K., Hill, J., Vigoroux, Y., Matsuoka, Y., Sanchez G., J., Liu, K., Bucker, E., Doebley, J.: Genetic diversity and population structure of teosinte. — Genetics 169: 2241–2254, 2005.Furini, A., Jewell, C.: Somatic embryogenesis and plant regeneration of maize/Tripsacum hybrids. — Maydica 40: 205–210, 1995.García, M.D., Molina, M. del C.: Embryo rescue and induction of somatic embryogenesis as a method to overcome seed inviability in Zea mays ssp. mays (2n = 40) × Zea mays ssp. parviglumis crosses. — Biol. Plant. 44: 497–501, 2001.García, M.D., Molina, M. del C., Caso, 0.H.: [Maize (Zea mays ssp. mays) plant regeneration from tissue culture and its applications in maize breeding.] — Rev. Fac. Agron. UNLP 68: 15–25, 1992. [In Spanish]Goluboskaya, I.N., Harper, L.C., Pawlowski, W.P., Schicnes, D.; Cande, W.Z.: The pam1 gene is required for meiotic bouquet formation and efficient homologous synapsis in maize (Zea mays L.). — Genetics 162: 1979–1993, 2002.González, G., Poggio, L.: Karyotype of Zea luxurians and Z. mays subsp. mays using FISH/DAPI, and analysis of meiotic behavior of hybrids. — Genome 54: 26–32, 2011.Harper, L., Golubovskaya, I., Cande, W.Z.: A bouquet of chromosomes. — J. Cell. Sci. 117: 4025–4032, 2004.Iltis, H.H., Benz B.F: Zea nicaraguensis (Poaceae), a new teosinte from Pacific coastal Nicaragua. — Novon 10: 382–390, 2000.Iltis, H.H.; Dobley J.: Taxonomy of Zea (Gramineae). II Subspecific categories in the Zea mays comple× and a generic synopsis. — Amer. J. Bot. 67: 994–1004, 1980.Jackson, R.C.: Polyploidy and diploidy: new perspectives on chromosome pairing and its evolutionary implications. — Amer. J. Bot. 69: 1512–1523, 1982.Jackson, R.C., Murray, B.G.: Colchicine-induced quadrivalent formation in Helianthus: evidence of ancient polyploidy. — Theor. appl. Genet. 64: 219–222, 1983.Jenczewski, E., Alix, K.: From diploids to allopolyploids: the emergence of efficient pairing control genes in plants. — Crit. Rev. Plant Sci. 23: 21–25, 2004.Jenkins, G., Chatterjee, R.: Chromosome structure and pairing preferences in tetraploid rye (Secale cereale). — Genome 37: 784–793, 1994.Molina, M. del C.: Estudios citogenéticos evolutivos del Género Zea. [Cytogenetic Study of Zea Genus Evolution] — PhD Thesis, Polytechnic University of Valencia, Valencia 2011. [In Spanish].Molina, M. del C., Chorzempa, S.E., García, M.D.: Meiotic pairing in the hybrid (Zea mays × Zea diploperennis) × Zea luxurians. — Maize Genet. Coop. Newslett. 79: 5–7, 2005.Molina, M. del C., García, M.D.: Influence of ploidy levels on phenotypic and cytogenetic traits in maize and Zea perennis hybrids. — Cytologia 64: 101–109, 1999.Molina, M. del C., García, M.D.: Meiotic pairing in the interspecific hybrid Zea mays, Z. perennis and Zea diploperennis. — Maize Genet. Coop. Newslett. 74: 42–43, 2000.Molina, M. del C., García, M.D.: Ploidy levels affect phenotype and cytogenetic traits in Zea mays ssp. mays (2n = 20 or 40) and Zea mays ssp. parviglumis hybrids — Cytologia 66: 189–196, 2001.Molina, M. del C., García, M.D., López C.G., Moreno Ferrero, V.: Meiotic pairing in the hybrid (Zea diploperennis × Zea perennis) × Zea mays and its reciprocal. — Hereditas 141: 135–141, 2004.Molina, M. del C., Naranjo, C.A.: Cytogenetic studies in the genus Zea. I. Evidence for five as the basic chromosomes number. — Theor. appl. Genet. 73: 542–550, 1987.Naranjo, C.A., Molina, M. del C., Poggio, L.: [Evidence of a basic number x = 5 in the genus Zea and its importance in studies of the origin of maize] — Acad. Nac. Cs. Ex. Fis. Nat. 5: 75–84, 1989. [In Spanish].Naranjo, C.A., Poggio, L., Molina, M. del C., Bernatene, E.: Increase in multivalent frequency in F1 hybrids of Zea diploperennis × Z. perennis by colchicine treatment. — Hereditas 120: 241–244, 1994.Poggio, L., Molina, M. del C., Naranjo, C.A.: Cytogenetic studies in the genus Zea. 2- colchicine-induced multivalents. — Theor. appl. Genet. 79: 461–464, 1990.Ruiz, C., Sanchez, J.J., Aguilar, S.M.: Potential geographical distribution of teosinte in Mexico: a GISH approach. — Maydica 46: 105–110, 2001.Santos, J.L., Lacadena, J.R., Cermeno, M.C., Orellana, J.: Nucleolar organizer activity in wheat-barley chromosome addition lines. — Heredity 53: 425–429, 1984.Santos, J.L., Orellana, J.: Pairing competition between identical and homologous chromosome in rye and grasshoppers. — Genetics 104: 677–684, 1983.Schnable, J.C., Freeling, M.: Genes identified by visible mutant phenotypes show increased bias toward one of two subgenomes of maize. — PLoS ONE 6–3: e17855. Doi:101371/journal.pone.0017855, 2011.Schnable, J.C., Springer, N.M., Freeling, M.: Differentiation of maize subgenome by genome dominance and both ancient and ongoing gene loss. — PNAS 108: 4069–4074, 2011.Sokal, R.R., Rohlf, Y.: Biometría. — W.H. Freeman and Company, San Francisco 1978.Swanson-Wagner R., Eichten S., Kumari S., Tiffin P., Stein J., Ware D., Springer N.: Pervasive gene content variation and copy number variation in maize and its undomesticated progenitor. — Genome Res., in press, 2012.Swigonová, Z., Lai, J., Ma, J., Ramakrisma, W., Llaca, V., Bennetzen, J., Messing, J.: Close split of sorghum and maize genome progenitors. — Genome Res. 14: 1916–1923, 2004.Wendel, J.: Genome evolution in polyploidy, — Plant mol. Biol. 42: 225–229, 2000.Zickler, D., Kleckner, N.: The leptotene-zygotene transition of meiosis. — Annu. Rev. Genet. 32: 619–697, 1998

Métodos de plano crítico para el análisis de fatiga multiaxial en el acero inoxidable 316

El presente trabajo estudia la capacidad de predicción de los modelos de plano crítico para casos de fatiga multiaxial. El material que se estudia es un acero inoxidable 316. Los caminos de carga aplicados son uniaxiales y biaxiales en la superficie de la probeta. El siguiente estudio realiza una comparativa de las predicciones de vida a fatiga y ángulo de grieta de los modelo Wang-Brown, Fatemi-Socie, Liu I y Liu II. Se observó que la mejor predicción de vida fue devuelta por el modelo de Liu II y para el ángulo de grieta por Liu I.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Los autores agradecen la financiación aportada para la realización de este trabajo al Ministerio de Economía y Competitividad (referencia MAT2016-76951-C2-2-P)

Determinación experimental de la carga de apertura de grieta en fatiga bajo cargas aleatorias

El concepto de carga de apertura o cierre de grieta es ampliamente utilizado en fatiga para justificar el comportamiento del crecimiento de grietas con distintas relaciones de carga y el efecto de interacción de las cargas. Hasta la fecha son numerosas las técnicas experimentales propuestas para medir la apertura de grieta y entre ellas los métodos de flexibilidad son ampliamente utilizados por su simplicidad. En este trabajo se propone una modificación del método propuesto por la ASTM y se presentan los resultados obtenidos en ensayos de crecimiento de grietas por fatiga bajo cargas aleatorias. Así mismo, los valores experimentales de cargas de apertura son comparados con los calculados analíticamente por un modelo de simulación tipo “strip-yield” implementado en el software NASGRO. En general, se ha encontrado una concordancia razonablemente buena entre los valores experimentales y los obtenidos por simulación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Los autores agradecen la financiación aportada para la realización de este trabajo al Ministerio de Economía y Competitividad (referencia MAT2016-76951-C2-2-P)

The electronic structure of zircon-type orthovanadates: Effects of high-pressure and cation substitution

The electronic structure of four ternary-metal oxides containing isolated vanadate ions is studied. Zircon-type YVO4, YbVO4, LuVO4, and NdVO4 are investigated by high-pressure optical-absorption measurements up to 20 GPa. First-principles calculations based on density-functional theory were also performed to analyze the electronic band structure as a function of pressure. The electronic structure near the Fermi level originates largely from molecular orbitals of the vanadate ion, but cation substitution influence these electronic states. The studied ortovanadates, with the exception of NdVO4, undergo a zircon-scheelite structural phase transition that causes a collapse of the band-gap energy. The pressure coefficient dEg/dP show positive values for the zircon phase and negative values for the scheelite phase. NdVO4 undergoes a zircon-monazite-scheelite structural sequence with two associated band-gap collapses.Comment: 35 pages, 11 figures, 2 Tables, 52 reference

Humanitarian organizations' information practices : procedures and privacy concerns for serving the undocumented

Many humanitarian organizations in the United States work with the information of undocumented migrants to help them secure services that might otherwise be unattainable to them. Information and communication technologies can help their work, but can also significantly exacerbate the risks that undocumented individuals are facing, and expose them to security breakages, leaks, hacks, inadvertent disclosure, and courts requests. This study aims to provide a preliminary understanding of the information practices and systems that US humanitarian organizations employ to protect the privacy of the undocumented individuals they serve. To do so, we conducted interviews and an analysis of organizations' working documents within humanitarian organizations on the US West Coast, including advocacy groups and organizations with ties to higher education. Our outcomes show gaps between current legal standards, technology best practices, and the day‐to‐day functioning of the organizations. We contend the necessity of support to humanitarian organizations in further developing standards and training for digital privacy

GIADA performance during Rosetta mission scientific operations at comet 67P

The Grain Impact Analyser and Dust Accumulator (GIADA) instrument onboard Rosetta studied the dust environment of comet 67P/Churyumov–Gerasimenko from 3.7 au inbound, through perihelion, to 3.8 au outbound, measuring the dust flow and the dynamic properties of individual particles. GIADA is composed of three subsystems: 1) Grain Detection System (GDS); 2) Impact Sensor (IS); and 3) Micro-Balances System (MBS). Monitoring the subsystems’ performance during operations is an important element for the correct calibration of scientific measurements. In this paper, we analyse the GIADA inflight calibration data obtained by internal calibration devices for the three subsystems during the period from 1 August 2014 to 31 October 2015. The calibration data testify a nominal behaviour of the instrument during these fifteen months of mission; the only exception is a minor loss of sensitivity for one of the two GDS receivers, attributed to dust contamination