65 research outputs found
Computation of the expansion parameters of femto-waveguides using a two dimensional micro-Raman map and guided modes
No full textThe expansion parameters of a numerical elastic model that simulates femtosecond laser-material interactions are computed. To achieve this, two dimensional micro-Raman mapping, an elastic-optic finite element model,and the experimental intensity profile of the guided modes were used. To complement this data, the Raman deformation potential constants of the lithium niobate A1(TO4) phonon were obtained and compared with those reported in previous works.Fil: Tejerina, Matías Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); ArgentinaFil: Torchia, Gustavo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Investigaciones Opticas (i); Argentin
A low-cost mechatronic system for sol-gel spraypyrolysis technique
No full textThis work presents a design of a low-cost spray pyrolysis automatized system which allows to manufacture high quality thin films. In particular, the thermal component of this instrument is modelled in different operation conditions, analyzed, and controlled. Also, different configurations for the whole instrument are analyzed.Fil: Oviedo, Martin. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Alvira, Fernando Carlos. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Apaolaza, Agustin. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Martiarena, Juan Francisco. Universidad Nacional de La Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Tejerina, Matías Rubén. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Tecnología de Recursos Minerales y Cerámica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Tecnología de Recursos Minerales y Cerámica; Argentin
Hydrostatic-pressure dependence of Raman-active optical phonons in Nd:Mg:LiNbO3
No full textIn this work, we report the frequency variation of Raman phonon modes of a doped Nd:Mg:LiNbO3 crystal under high hydrostatic pressure up to 6.5 GPa. Whereas most of the phonon modes are not affected by doping, showing the same pressure dependence of their frequency as for undoped LiNbO3, there are three exceptions: The A1(TO)2, the A1(TO)3 and the E(TO)4 phonons. These modes exhibit a considerably different pressure coefficient, which is mainly attributed to the influence of Mg ions occupying Nb-sites in the lithium niobate matrix.Fil: Tejerina, Matías Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); ArgentinaFil: Pereira Da Silva, K.. Universidade Estadual Do Ceara; Brasil. Institut de Ciència de Materials de Barcelona; EspañaFil: Goñi, A. R.. Institut de Ciència de Materials de Barcelona; España. Institució Catalana de Recerca i Estudis Avancats; EspañaFil: Torchia, Gustavo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones Opticas (i); Argentin
Efeitos do solventes na deposição de filmes finos de ZnO por pulverização pirolítica sol-gel
No full textIn this work we analyze the characteristics of the ZnO film made by sol-gel pyrolytic nebulization, in terms of the variation of solvent composition. For this purpose, we present and discuss a characterization using macroscopic images of the films, X-ray diffraction (XRD) and UV-VIS-NIR transmittance spectroscopy. Among the relevant results, increase in the water/ethanol ratio was found to be related to an increase in film thickness. Furthermore, the thickness, coverage area and transparency of the film were also found to be dependent on the solvent composition of the starting solution. This study contributes to the understanding of the relationship between a major growth parameter such as the composition of the starting solution, and the desired characteristics of ZnO films that are relevant for technological applications.En este trabajo, se analizaron las características de películas de ZnO fabricadas con nebulización pirolítica sol-gel, en términos de la variación de la composición del solvente. Para este propósito, se muestra y discute una caracterización usando imágenes macroscópicas de las películas, difracción de rayos X (XRD) y espectroscopía de transmitancia UV-VIS-NIR. Entre los resultados relevantes se obtuvo que el aumento de la relación agua/etanol está relacionado con un aumento en el espesor de los films. Además, se encontró que el espesor, el área de cobertura y la transparencia de las películas también dependían de la composición del solvente de la solución de partida. Este estudio ayuda a comprender la relación entre un parámetro de crecimiento importante, como lo es la composición de la solución de partida y las características deseadas de las películas de ZnO que son importantes para las aplicaciones tecnológicas.Neste trabalho foram analisadas as características do filme de ZnO fabricadas por nebulização pirolítica sol-gel, em termos da variação da composição do solvente. Para tanto, é mostrada e discutida uma caracterização utilizando imagens macroscópicas dos filmes, difração de raios X (XRD) e espectroscopia de transmitância UV-VIS-NIR. Dentre os resultados relevantes, obteve-se que o aumento da relação água/etanol está relacionado ao aumento da espessura dos filmes. Além disso, verificou-se que a espessura, a área de cobertura e a transparência do filme também dependiam da composição do solvente da solução inicial. Este estudo ajuda a compreender a relação entre um importante parâmetro de crescimento, como a composição da solução inicial, e as características desejadas dos filmes de ZnO que são importantes para aplicações tecnológicas
Insect Antifeedant Components of Senecio fistulosus var. fistulosus—Hualtata
No full text© The Author(s).From a bioactive methanolic extract of Senecio fistulosus, the antifeedant effects of the alkaloidal and non-alkaloidal fractions were tested against the insects Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi, with the non-alkaloidal fraction being antifeedant. The phytochemical study of the non-alkaloidal fraction of S. fistulosus, resulted in the isolation of four compounds, two 9-oxo-furanoeremophilanes (1, 2), an eremophilanolide, 1β,10β-epoxy-6-acetoxy-8α-hydroxy-eremofil-7(11)-en-8β,12-olide (3) and a maaliol derivative (4). The alkaloidal fraction yielded two known pyrrolizidine alkaloids (5, 6). Compounds 1, 3 and 4 are new natural products. Furanoeremophilane 2 was a strong antifeedant against S. littoralis and maaliane 4 inhibited the settling of M. persicaeThis work has been supported by grants CTQ2015-64049-C3-1-R, (MINECO/FEDER), UMAG 027103-026703 (Dirección de Investigación, Chile) and a JAEPRE-DOC-CSIC predoctoral fellowship to L.R.V.Peer reviewe
Matías Ramón Martínez y la Revista de Extremadura
No full text[ES]: En este trabajo se resumen los artículos publicados por M. R. Martínez en la Revista de Extremadura entre 1899 y 1904. Se estudia el comportamiento del autor en la revista, así como los temas tratados, las zonas investigadas o la regularidad de sus contribuciones. Entre sus colaboraciones destacan la presentación de documentos inéditos, las noticias sobre hallazgos arqueológicos, breves historias locales y críticas a libros históricos.[EN]: This paper summarizes articles published by M. R. Martinez in Revista de Extremadura between 1899 and 1904. We study the behavior of the author in the magazine, as well as topics, investigated areas or the regularity of his contributions. This collaborations include the presentation of unpublished documents news about archaeological finds, brief local stories and criticism of historical books.Peer reviewe
μ-Raman spectroscopy characterization of LiNbO3 femtosecond laser written waveguides
No full textThe following article appeared in Journal of Applied Physics 112.12 (2012): 123108 and may be found at http://scitation.aip.org/content/aip/journal/jap/112/12/10.1063/1.4769869In this paper, we present an iterative method which merges experimental μ-Raman measurements and numerical simulations to describe femtosecond written waveguides in LiNbO3 crystals. This method is based on the deformation potential theory, and uses the finite element method to analyze elastic deformations after femtosecond laser micro-explosions in x-cut Mg:LiNbO3 crystals. The resultant strain and refractive index field after laser interaction were estimated and yielded similar values to those obtained in other works. The LiNbO3 Raman deformation potential constants were also estimated in this work.This work was partially supported by Agencia Nacional de Promoción Científica y Tecnológica (Argentina) under project PICT-2010-2575 and CONICET (Argentina) under project PIP 0394
Nickel-doped zinc oxide thin films made by spray pyrolysis: experimental characterization and theoretical analyses
No full textAbstract A study of ZnO-based ceramic films prepared by the spray-pyrolysis technique is presented. Pure and Ni-doped thin film samples were deposited as a coating on a glass substrate and experimentally characterized using scanning electron and atomic force microscopies, X-ray diffraction, and UV-vis-NIR spectroscopy. The morphologic, crystallographic, and optical properties were analyzed. Structural and electronic properties were compared to predictions obtained from computational calculations based on the density functional theory plus U approach (DFT+U). All these simulations provided additional data that could be used as a reference for material modeling and a better understanding of the experimental results. It was found that spray pyrolysis can be used to produce thin film ceramic samples (~300 nm) with low amounts (<5%) of Ni impurities substitutionally located at the cationic sites of the ZnO wurtzite host structure. The results of this investigation showed that an experimental and theoretical study aided in a better characterization of the thin films, and helped to outline a more robust model of the samples
Orchestina valquiria Izquierdo 2017, new species
No full textOrchestina valquiria Izquierdo, new species Figures 118, 131D–F, 134D, 137E, 140A, C, 142B, map 26 TYPE: Male holotype from Brazil: Amazonas: Presidente Figueiredo: Usina Hidrelétrica de Balbina, -1.81666°, -59.41666°, July 14, 2006, R. Saturnino, deposited in MPEG 010664, PBI_ OON 40480. ETYMOLOGY: A noun in apposition; because, while analyzing this species, the first author was listening to Die Walküre (“The Valkyrie”), an opera by Richard Wagner, we decided to give its name to this species. DIAGNOSIS: Males can be distinguished by the presence of a short embolus flanked by a short apophysis and a highly coiled sperm duct (figs. 131D–F, 140A, C). Females can be distinguished by the absence of anterior apodemes on the anterior receptaculum and by the lateral projections, emerging near median half of the anterior receptaculum (figs. 134D, 137E, 142B). MALE (PBI_ OON 40480): Total length 1.40. Habitus as in figure 118A–C. CEPHALOTHO- RAX: Carapace orange. Labium rectangular. LEGS: Yellow. GENITALIA: Palp proximal segments yellow, cymbium yellow; embolus short; sperm duct strongly coiled, with many loops (figs.131D–F, 140A, C). FEMALE (PBI_ OON 40491): Total length 1.55. Habitus as in figure 118D–F. CEPHALOTHO- RAX: Carapace pale orange. Sternum as long as wide, yellow. Chelicerae, endites, labium yellow. GENITALIA: External pockets absent, internal pockets well developed; anterior receptaculum without anterior apodemes, nearly triangular, with widened lateral projections at base; posterior receptaculum present, posterior apodeme formed by entire plate (figs. 134D, 137E, 142B). DISTRIBUTION: states of Amazonas, Pará, Amapá, Piuaí, and Tocantins, Brazil (map 26). OTHER MATERIAL EXAMINED: BRAZIL: Amapá: Laranjal do Jari: Cachoeira de Santo Antônio, (-0.841944°, -52.515833°), Feb. 22, 2003, J.A.P. Barreiros, 13, 1♀ (MPEG 010400, PBI_ OON 40470). Pará: Melgaço: Flona Caxiuanã, -1.85527°, -51.43250°, Nov. 22, 2005, N. Abrahim, 1♀ (MPEG 18949, PBI_ OON 42166); same data, -1.79222°, -51.43305°, Nov. 18, 2005, J.A.P. Barreiros, 1♀ (MPEG 19020, PBI_ OON 42169); same data, 1♀ (MPEG 18824, PBI_ OON 42178); same data, Nov. 23, 2005, J.H.C. Cordeiro, 1♀ (MPEG 18943, PBI_ OON 42170). Piaui: Castelo do Piauí: ECB Rochas Ornamentais LTDA, Fazenda Bonito, -5.23055°, -41.70027°, Mar. 28, 2005, M.P. Albuquerque, 2♀ (MPEG 015659, PBI_ OON 40491). Tocantins: Palmas: Serra do Lajeado, (-10.045551°, -48.254163°), Apr. 17, 2005, to Apr. 25, 2005, I. Knysak and R. Martins, 2♀ (IBSP 124514, PBI_ OON 30370).Published as part of Izquierdo, Matías Andrés & Ramírez, Martín J., 2017, Taxonomic Revision Of The Jumping Goblin Spiders Of The Genus Orchestina Simon, 1882, In The Americas (Araneae: Oonopidae), pp. 1 in Bulletin of the American Museum of Natural History 2017 (410) on page 1, DOI: 10.1206/0003-0090-410.1.1, http://zenodo.org/record/540561
in Europe
No full text© The Author(s) 2023. Published by Oxford University Press on behalf of Entomological Society of America.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Philaenus spumarius L., the main vector of Xylella fastidiosa (Wells) in Europe, is a univoltine species that overwinters in the egg stage, and its nymphs emerge in late winter or spring. Predicting the time of egg hatching is essential for determining the precise times for deploying control strategies against insect pests. Here, we monitored P. spumarius eggs from oviposition to egg hatching together with the daily temperatures and relative humidities at four field locations that were located at different altitudes in central Spain. The collected data were used to build a growing degree day (GDD) model to forecast egg hatching in the Iberian Peninsula. Furthermore, the model was validated with field observations that were conducted in Spain. The model was then used as a decision-support tool to calculate the optimum timing for applying control actions against P. spumarius. Our results suggest that controlling nymphs at two different dates would target the highest percentages of nymphal populations present in the field. Our model represents a first step for predicting the emergence of nymphs and adopting timely control actions against P. spumarius. These actions could limit disease spread in areas where X. fastidiosa is present.The work was funded by the Ministerio de Ciencia e Innovación under grant AGL2017-89604-R and fellowship PRE2018-083307 (C. L., M. M., A.M., and A. F.) and Grants RTI2018-095441-B-C22 (SuMaEco) and PID2021-123723OB-C22 (CYCLE) funded by MCIN/AEI/10.13039/501100011033 and by ‘ERDF A way of making Europe’ (A. G. R. and M. A. M.) and Grant MDM-2017-0711 (María de Maeztu Excellence Unit) funded by MCIN/AEI/10.13039/501100011033 (A. G. R. and M. A. M.).With funding from the Spanish government through the ‘María de Maeztu Unit of Excelence’ accreditation (MDM-2017-0711).Peer reviewe
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