Supercritical antisolvent particle precipitation and fractionation of rosemary (Rosmarinus officinalis L.) extracts

The simultaneous fractionation and precipitation of an ethanolic extract of rosemary (Rosmarinus officinalis L.) using supercritical carbon dioxide anti-solvent technique was studied, with the target of separate in two different fractions the key antioxidants of rosemary (i.e. rosmarinic acid, carnosic acid and carnosol). The effect of pressure and temperature on the fractionation process was investigated, together with the morphology and particle size distribution of the precipitates. Additionally, the chemical composition of the oleoresins were analyzed and reported. In the range of pressures (9-20 MPa) and temperatures (313-333 K) used in this work, the precipitates presented a 2-3 fold enrichment of rosmarinic acid, while carnosic acid and carnosol were concentrated (2-3 fold enrichment) in the oleoresin fractions. Furthermore, in general, oleoresins presented higher antioxidant activity than precipitates. Particles produced with a nozzle of diameter 101.6 μm were smaller and more spherical with increasing pressure (mean value 4-10 μm at 20 MPa) and decreasing temperatureThe authors gratefully acknowledge the financial support from Ministerio de Economía y Competitividad of Spain (Proyect AGL2016- 76736-C3-1-R). Somaris E. Quintana is grateful for the funding provided by Gobernación de Bolivar and Fundación Ceiba, Colombia, in the project “Bolívar Gana con Cienci

Electrical Responses of Pinus halepensis Mill. as an Indicator of Wildfire Risk in Mediterranean Forests by Complementing Live Fuel Moisture

[EN] Pinus halepensis forests, as Mediterranean-type ecosystems, are subject to high levels of wildfire risk in times of drought, with meteorological conditions of water stress and very high temperatures, mainly in summer. Considering the difficulty of knowing the phenological state of this species, the objective of this research was to evaluate the possibility of implementing the electrical responses (voltage and short-circuit current) as a variable in fire risk management models, compared to live fuel moisture. On the one hand, the obtained results demonstrate non-significant differences between the moisture content of the different fractions of the living branches (base and half of the branch and live fuel), even in times of drought with hydric stress and very high temperatures. Live fuel moisture of Pinus halepensis does not show significant seasonal variations under the influence of extreme fire risk factors. For this reason, it should be complemented with other variables for fire risk management models. On the other hand, the differences registered in the electrical signal show oscillations with significant variations, which are strongly correlated with the periods of extremely favourable meteorological conditions for wildfires. So, the voltages measured show ranges that correspond with great accuracy to the FWI. Voltage variation is dependent on the hydraulic dynamic plant behaviour and a result of the physiological response of pine trees to abiotic stress of drought. It is an easy-to-measure electrical parameter as well as a very reliable indicator with a high correlation with wildfire risk. Thus, electrical responses could add more knowledge about the phenological state of the trees in dependence on stress climatic conditions, allowing integration of these variables in the preventive wildfire modelling and managementZapata, R.; Oliver Villanueva, JV.; Lemus Zúñiga, LG.; Mateo Pla, MÁ.; Luzuriaga, JE. (2022). Electrical Responses of Pinus halepensis Mill. as an Indicator of Wildfire Risk in Mediterranean Forests by Complementing Live Fuel Moisture. Forests. 13(8):1-19. https://doi.org/10.3390/f1308118911913

Linear and nonlinear optical properties of carbon nanotube-coated single-mode optical fiber gratings

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.36.002104. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] Single-wall carbon nanotube deposition on the cladding of optical fibers has been carried out to fabricate an all-fiber nonlinear device. Two different nanotube deposition techniques were studied. The first consisted of repeatedly immersing the optical fiber into a nanotube supension, increasing the thickness of the coating in each step. The second deposition involved wrapping a thin film of nanotubes around the optical fiber. For both cases, interaction of transmitted light through the fiber core with the external coating was assisted by the cladding mode resonances of a tilted fiber Bragg grating. Ultrafast nonlinear effects of the nanotube-coated fiber were measured by means of a pump-probe pulses experiment. © 2011 Optical Society of America.This work was financially supported by the European Commission under the FP7 EURO-FOS Network of Excellence (ICT-2007-2-224402), the Ministerio de Educación y Ciencia SINADEC project (TEC2008-06333), and the Natural Sciences and Engineering Research Council of Canada (NSERC). The work of G. E. Villanueva was supported by the Ministerio de Educación y Ciencia Formación de Profesorado Universitario programs. The work of P. Pérez-Millán was supported by the Juan de la Cierva program, JCI-2009-05805.Villanueva Ibáñez, GE.; Jakubinek, M.; Simard, B.; Oton Nieto, CJ.; Matres Abril, J.; Shao, L.; Pérez Millán, P.... (2011). Linear and nonlinear optical properties of carbon nanotube-coated single-mode optical fiber gratings. Optics Letters. 36(11):2104-2106. https://doi.org/10.1364/OL.36.002104S210421063611Sakakibara, Y., Rozhin, A. G., Kataura, H., Achiba, Y., & Tokumoto, M. (2005). Carbon Nanotube-Poly(vinylalcohol) Nanocomposite Film Devices: Applications for Femtosecond Fiber Laser Mode Lockers and Optical Amplifier Noise Suppressors. Japanese Journal of Applied Physics, 44(4A), 1621-1625. doi:10.1143/jjap.44.1621Chow, K. K., Yamashita, S., & Song, Y. W. (2009). A widely tunable wavelength converter based on nonlinear polarization rotation in a carbon-nanotube-deposited D-shaped fiber. Optics Express, 17(9), 7664. doi:10.1364/oe.17.007664Set, S. Y., Yaguchi, H., Tanaka, Y., & Jablonski, M. (2004). Ultrafast Fiber Pulsed Lasers Incorporating Carbon Nanotubes. IEEE Journal of Selected Topics in Quantum Electronics, 10(1), 137-146. doi:10.1109/jstqe.2003.822912Chow, K. K., Tsuji, M., & Yamashita, S. (2010). Single-walled carbon-nanotube-deposited tapered fiber for four-wave mixing based wavelength conversion. Applied Physics Letters, 96(6), 061104. doi:10.1063/1.3304789Chow, K. K., & Yamashita, S. (2009). Four-wave mixing in a single-walled carbon-nanotube-deposited D-shaped fiber and its application in tunable wavelength conversion. Optics Express, 17(18), 15608. doi:10.1364/oe.17.015608Choi, S. Y., Rotermund, F., Jung, H., Oh, K., & Yeom, D.-I. (2009). Femtosecond mode-locked fiber laser employing a hollow optical fiber filled with carbon nanotube dispersion as saturable absorber. Optics Express, 17(24), 21788. doi:10.1364/oe.17.021788Chan, C.-F., Chen, C., Jafari, A., Laronche, A., Thomson, D. J., & Albert, J. (2007). Optical fiber refractometer using narrowband cladding-mode resonance shifts. Applied Optics, 46(7), 1142. doi:10.1364/ao.46.001142Kingston, C. T., Jakubek, Z. J., Dénommée, S., & Simard, B. (2004). Efficient laser synthesis of single-walled carbon nanotubes through laser heating of the condensing vaporization plume. Carbon, 42(8-9), 1657-1664. doi:10.1016/j.carbon.2004.02.020Jakubinek, M. B., Johnson, M. B., White, M. A., Guan, J., & Simard, B. (2010). Novel Method to Produce Single-Walled Carbon Nanotube Films and Their Thermal and Electrical Properties. Journal of Nanoscience and Nanotechnology, 10(12), 8151-8157. doi:10.1166/jnn.2010.3014Vallaitis, T., Koos, C., Bonk, R., Freude, W., Laemmlin, M., Meuer, C., … Leuthold, J. (2008). Slow and fast dynamics of gain and phase in a quantum dot semiconductor optical amplifier. Optics Express, 16(1), 170. doi:10.1364/oe.16.00017

Position Dependent Optical Back-Action in Cantilever Resonators

Position Dependent Optical Back-Action in Cantilever Resonator

Seasonal variations of electrical signals of Pinus halepensis Mill. in Mediterranean forests in dependence on climatic conditions

This is an Accepted Manuscript of an article published by Taylor & Francis in Plant Signaling & Behavior on 2021, available online: http://www.tandfonline.com/10.1080/15592324.2021.1948744[EN] The temporal evolution of the electrical signal generated by Pinus halepensis was measured in a sample of 15 trees. Weekly experiments were carried out during a long-term campaign lasting over a year, while trials with a high frequency of measurements were also performed during several days. In the latter case, day-night oscillations of the electrical magnitudes were observed. Additionally, punctual meteorological events such as rainfall and electrical storms affect the electrical signal as well. The measured electrical intensity grows exponentially with the voltage. In fact, no electrical intensity that exceeds the threshold of 0.01 ¿A is gathered when voltage values are lower than 0.6 V. In general, higher electrical signals were gathered during the rainy seasons with moderate temperatures; while very low signals, including few measures of zero intensity, were obtained during the most stressful periods over the year, mainly by mid-summer. There is a strong correlation between the rainfall and the electrical signal. The rain-intensity correlation, together with sustained intensity values during the reproductive period in spring, suggests that this electrical magnitude could be an indicator of the physiological state of the tree and thus used for in situ and minimally invasive forest monitoring.Zapata, R.; Oliver Villanueva, JV.; Lemus Zúñiga, LG.; Fuente, D.; Mateo Pla, MÁ.; Luzuriaga, JE.; Moreno, J. (2021). Seasonal variations of electrical signals of Pinus halepensis Mill. in Mediterranean forests in dependence on climatic conditions. Plant Signaling & Behavior. 16(10):1-13. https://doi.org/10.1080/15592324.2021.1948744113161

Dynamic control of the operation regimes of a mode-locked fiber laser based on intracavity polarizing fibers: experimental and theoretical validation

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.001971. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] An intracavity polarizing fiber is proposed to control the emission regime of a passively mode-locked fiber laser. Stable operation in self-starting high and low dispersion soliton mode-locking and 100 GHz multiwavelength regimes is demonstrated through numerical simulations and experimental validation. Mode-locking stability is ensured by a saturable absorber in the ring cavity. The effective selection of operation regime is dynamically carried out by controlling the intracavity polarization state.This work was financially supported by the EuropeanCommission under the FP7 EURO-FOS NoE (ICT-2007-2-224402). The work of G. E. Villanueva was supported by the MEC-FPU programs. The work of P. Pérez-Millán was supported by the Juan de la Cierva program, JCI-2009-05805.Villanueva Ibáñez, GE.; Pérez Millán, P. (2012). Dynamic control of the operation regimes of a mode-locked fiber laser based on intracavity polarizing fibers: experimental and theoretical validation. Optics Letters. 37(11):1971-1973. https://doi.org/10.1364/OL.37.001971S197119733711Fermann, M. E., & Hartl, I. (2009). Ultrafast Fiber Laser Technology. IEEE Journal of Selected Topics in Quantum Electronics, 15(1), 191-206. doi:10.1109/jstqe.2008.2010246Ippen, E. P. (1994). Principles of passive mode locking. Applied Physics B Laser and Optics, 58(3), 159-170. doi:10.1007/bf01081309Haus, H. (1975). Theory of mode locking with a slow saturable absorber. IEEE Journal of Quantum Electronics, 11(9), 736-746. doi:10.1109/jqe.1975.1068922Kurtner, F. X., der Au, J. A., & Keller, U. (1998). Mode-locking with slow and fast saturable absorbers-what’s the difference? IEEE Journal of Selected Topics in Quantum Electronics, 4(2), 159-168. doi:10.1109/2944.686719Zhang, Z., Zhan, L., Xu, K., Wu, J., Xia, Y., & Lin, J. (2008). Multiwavelength fiber laser with fine adjustment, based on nonlinear polarization rotation and birefringence fiber filter. Optics Letters, 33(4), 324. doi:10.1364/ol.33.000324Li, S., Chen, X., Kuksenkov, D. V., Koh, J., Li, M.-J., Zenteno, L. A., & Nolan, D. A. (2006). Wavelength tunable stretched-pulse mode-locked all-fiber erbium ring laser with single polarization fiber. Optics Express, 14(13), 6098. doi:10.1364/oe.14.006098Liang, P. S., Zhang, Z. X., Kuang, Q. Q., & Sang, M. H. (2009). All-fiber birefringent filter with fine tunability and changeable spacing. Laser Physics, 19(11), 2124-2128. doi:10.1134/s1054660x09210063Marcuse, D. (1990). Simplified analysis of a polarizing optical fiber. IEEE Journal of Quantum Electronics, 26(3), 550-557. doi:10.1109/3.52132Menyuk, C. R. (1989). Pulse propagation in an elliptically birefringent Kerr medium. IEEE Journal of Quantum Electronics, 25(12), 2674-2682. doi:10.1109/3.40656Smith, N. J., Blow, K. J., & Andonovic, I. (1992). Sideband generation through perturbations to the average soliton model. Journal of Lightwave Technology, 10(10), 1329-1333. doi:10.1109/50.166771Ruehl, A., Wandt, D., Morgner, U., & Kracht, D. (2008). On wave-breaking free fiber lasers mode-locked with two saturable absorber mechanisms. Optics Express, 16(11), 8181. doi:10.1364/oe.16.00818

Metodología WebML aplicada a un sistema de gestión de calidad en centros de investigación

Este trabajo presenta los resultados obtenidos, producto de la aplicación de la línea de investigación sobre sistemas de gestión de calidad (SGC) en la Universidad Nacional de Salta, sobre al estudio de la familia de Normas ISO aplicadas a Instituciones Educativas, en particular al Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), dependiente de la Facultad de Ciencias Exactas. Todos los actores participantes del centro de investigación, tales como alumnos, docentes, personal de apoyo administrativo, investigadores, etc. persiguen como objetivo lograr la calidad en la educación, acorde a los requisitos legales y académicos establecidos por la institución. Para lograr este objetivo es necesario adoptar un modelo internacional de gestión de la calidad, en este caso se eligió a la familia de Normas ISO 9.001, el cual es un modelo que plantea un conjunto de criterios y elementos estandarizados cuya aplicación, evaluación y seguimiento busca facilitar el éxito de la gestión de calidad, aplicada a la institución. Las entidades educativas, y en particular los centros de investigación, no son ajenas a esta tendencia, tanto es así que el Instituto Argentino de Normalización (IRAM), a través del Comité General de Aseguramiento de la Calidad, diseñó en marzo de 2001 “La Guía de Interpretación de la Norma ISO 9001 para la Educación” con el objetivo de proveer lineamientos de cómo comprender e implementar la norma ISO 9.001 en el ámbito de la educación. Esta investigación se plantea estudiar las directrices que guían a los centros de investigación que presten servicio de capacitación y formación en todos los niveles, en cuanto a la implementación de un sistema de gestión de calidad (SGC) eficaz que cumpla los requisitos de la norma ISO 9001:2008). Como una segunda instancia se plantea el análisis, diseño e implementación de un prototipo funcional de un sistema de gestión de calidad (SGC) para el Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), utilizando como metodología Web Modeling Lenguage (WebML), aplicando la herramienta CASE WebRatio. Se pretende que esta investigación sirva de referencia para cualquier implementación de calidad, dentro del ámbito educativo, y en especial en los centros de investigación.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Metodología WebML aplicada a un sistema de gestión de calidad en centros de investigación

Este trabajo presenta los resultados obtenidos, producto de la aplicación de la línea de investigación sobre sistemas de gestión de calidad (SGC) en la Universidad Nacional de Salta, sobre al estudio de la familia de Normas ISO aplicadas a Instituciones Educativas, en particular al Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), dependiente de la Facultad de Ciencias Exactas. Todos los actores participantes del centro de investigación, tales como alumnos, docentes, personal de apoyo administrativo, investigadores, etc. persiguen como objetivo lograr la calidad en la educación, acorde a los requisitos legales y académicos establecidos por la institución. Para lograr este objetivo es necesario adoptar un modelo internacional de gestión de la calidad, en este caso se eligió a la familia de Normas ISO 9.001, el cual es un modelo que plantea un conjunto de criterios y elementos estandarizados cuya aplicación, evaluación y seguimiento busca facilitar el éxito de la gestión de calidad, aplicada a la institución. Las entidades educativas, y en particular los centros de investigación, no son ajenas a esta tendencia, tanto es así que el Instituto Argentino de Normalización (IRAM), a través del Comité General de Aseguramiento de la Calidad, diseñó en marzo de 2001 “La Guía de Interpretación de la Norma ISO 9001 para la Educación” con el objetivo de proveer lineamientos de cómo comprender e implementar la norma ISO 9.001 en el ámbito de la educación. Esta investigación se plantea estudiar las directrices que guían a los centros de investigación que presten servicio de capacitación y formación en todos los niveles, en cuanto a la implementación de un sistema de gestión de calidad (SGC) eficaz que cumpla los requisitos de la norma ISO 9001:2008). Como una segunda instancia se plantea el análisis, diseño e implementación de un prototipo funcional de un sistema de gestión de calidad (SGC) para el Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), utilizando como metodología Web Modeling Lenguage (WebML), aplicando la herramienta CASE WebRatio. Se pretende que esta investigación sirva de referencia para cualquier implementación de calidad, dentro del ámbito educativo, y en especial en los centros de investigación.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Metodología WebML aplicada a un sistema de gestión de calidad en centros de investigación

Este trabajo presenta los resultados obtenidos, producto de la aplicación de la línea de investigación sobre sistemas de gestión de calidad (SGC) en la Universidad Nacional de Salta, sobre al estudio de la familia de Normas ISO aplicadas a Instituciones Educativas, en particular al Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), dependiente de la Facultad de Ciencias Exactas. Todos los actores participantes del centro de investigación, tales como alumnos, docentes, personal de apoyo administrativo, investigadores, etc. persiguen como objetivo lograr la calidad en la educación, acorde a los requisitos legales y académicos establecidos por la institución. Para lograr este objetivo es necesario adoptar un modelo internacional de gestión de la calidad, en este caso se eligió a la familia de Normas ISO 9.001, el cual es un modelo que plantea un conjunto de criterios y elementos estandarizados cuya aplicación, evaluación y seguimiento busca facilitar el éxito de la gestión de calidad, aplicada a la institución. Las entidades educativas, y en particular los centros de investigación, no son ajenas a esta tendencia, tanto es así que el Instituto Argentino de Normalización (IRAM), a través del Comité General de Aseguramiento de la Calidad, diseñó en marzo de 2001 “La Guía de Interpretación de la Norma ISO 9001 para la Educación” con el objetivo de proveer lineamientos de cómo comprender e implementar la norma ISO 9.001 en el ámbito de la educación. Esta investigación se plantea estudiar las directrices que guían a los centros de investigación que presten servicio de capacitación y formación en todos los niveles, en cuanto a la implementación de un sistema de gestión de calidad (SGC) eficaz que cumpla los requisitos de la norma ISO 9001:2008). Como una segunda instancia se plantea el análisis, diseño e implementación de un prototipo funcional de un sistema de gestión de calidad (SGC) para el Centro de Investigación y Desarrollo en Informática Aplicada (C.I.D.I.A.), utilizando como metodología Web Modeling Lenguage (WebML), aplicando la herramienta CASE WebRatio. Se pretende que esta investigación sirva de referencia para cualquier implementación de calidad, dentro del ámbito educativo, y en especial en los centros de investigación.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Frequency fluctuations in silicon nanoresonators

Frequency stability is key to performance of nanoresonators. This stability is thought to reach a limit with the resonator's ability to resolve thermally-induced vibrations. Although measurements and predictions of resonator stability usually disregard fluctuations in the mechanical frequency response, these fluctuations have recently attracted considerable theoretical interest. However, their existence is very difficult to demonstrate experimentally. Here, through a literature review, we show that all studies of frequency stability report values several orders of magnitude larger than the limit imposed by thermomechanical noise. We studied a monocrystalline silicon nanoresonator at room temperature, and found a similar discrepancy. We propose a new method to show this was due to the presence of frequency fluctuations, of unexpected level. The fluctuations were not due to the instrumentation system, or to any other of the known sources investigated. These results challenge our current understanding of frequency fluctuations and call for a change in practices