Search

Your search keyword '"Machado, D. I."' showing total 100 results
Start Over Author "Machado, D. I."
100 results on '"Machado, D. I."'

1. Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020

Author

Morgado, B. E., Sicardy, B., Braga-Ribas, F., Desmars, J., Gomes-Júnior, A. R., Bérard, D., Leiva, R., Ortiz, J. L., Vieira-Martins, R., Benedetti-Rossi, G., Santos-Sanz, P., Camargo, J. I. B., Duffard, R., Rommel, F. L., Assafin, M., Boufleur, R. C., Colas, F., Kretlow, M., Beisker, W., Sfair, R., Snodgrass, C., Morales, N., Fernández-Valenzuela, E., Amaral, L. S., Amarante, A., Artola, R. A., Backes, M., Bath, K-L., Bouley, S., Buie, M. W., Cacella, P., Colazo, C. A., Colque, J. P., Dauvergne, J-L., Dominik, M., Emilio, M., Erickson, C., Evans, R., Fabrega-Polleri, J., Garcia-Lambas, D., Giacchini, B. L., Hanna, W., Herald, D., Hesler, G., Hinse, T. C., Jacques, C., Jehin, E., Jørgensen, U. G., Kerr, S., Kouprianov, V., Levine, S. E., Linder, T., Maley, P. D., Machado, D. I., Maquet, L., Maury, A., Melia, R., Meza, E., Mondon, B., Moura, T., Newman, J., Payet, T., Pereira, C. L., Pollock, J., Poltronieri, R. C., Quispe-Huaynasi, F., Reichart, D., de Santana, T., Schneiter, E. M., Sieyra, M. V., Skottfelt, J., Soulier, J. F., Starck, M., Thierry, P., Torres, P. J., Trabuco, L. L., Unda-Sanzana, E., Yamashita, T. A. R., Winter, O. C., Zapata, A., and Zuluaga, C. A.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Centaur (10199) Chariklo has the first rings system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow the determination of sizes and shapes with kilometre accuracy and obtain characteristics of the occulting object and its vicinity. Using stellar occultations observed between 2017 and 2020, we aim at constraining Chariklo's and its rings physical parameters. We also determine the rings' structure, and obtain precise astrometrical positions of Chariklo. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the data sets, from which ingress and egress times, and rings' width and opacity were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and rings' structure. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirmed the detection of W-shaped structures within C1R and an evident variation of radial width. The observed width ranges between 4.8 and 9.1 km with a mean value of 6.5 km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating ring particle's size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3-sigma), and its width variations may indicate an eccentricity higher than 0.005. We fit a tri-axial shape to Chariklo's detections over eleven occultations and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8, 135.2 and 99.1 km. Ultimately, we provided seven astrometric positions at a milliarcseconds accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris., Comment: 32 pages, 11 Figures in the main text, paper was accepted for publication in Section 10. Planets and planetary systems of Astronomy and Astrophysics on 12/07/2021

Published
2021
Full Text
View/download PDF

2. The first observed stellar occultations by the irregular satellite (Saturn IX) Phoebe and improved rotational period

Author

Gomes-Júnior, A. R., Assafin, M., Braga-Ribas, F., Benedetti-Rossi, G., Morgado, B., Camargo, J. I. B., Vieira-Martins, R., Desmars, J., Sicardy, B., Barry, T., Campbell-White, J., Fernández-Lajús, E., Giles, D., Hanna, W., Hayamizu, T., Hirose, T., De Horta, A., Horvat, R., Hosoi, K., Jehin, E., Kerr, S., Machado, D. I., Mammana, L. A., Maybour, D., Owada, M., Rahvar, S., and Snodgrass, C.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We report six stellar occultations by (Saturn IX) Phoebe, an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 06 event is the first stellar occultation by an irregular satellite ever observed. The occultation chords were compared to a 3D shape model of the satellite obtained from Cassini observations. The rotation period available in the literature led to a sub-observer point at the moment of the observed occultations where the chords could not fit the 3D model. A procedure was developed to identify the correct sub-observer longitude. It allowed us to obtain the rotation period with improved precision over currently known value from literature. We show that the difference between the observed and the predicted sub-observer longitude suggests two possible solutions for the rotation period. By comparing these values with recently observed rotational light curves and single-chord stellar occultations, we can identify the best solution for Phoebe's rotational period as $9.27365 \pm 0.00002$ h. From the stellar occultations, we also obtained 6 geocentric astrometric positions in the ICRS as realised by the Gaia-DR2 with uncertainties at the 1-mas level., Comment: 13 pages, 12 figures

Published
2019
Full Text
View/download PDF

3. The 2014-2015 Brazilian Mutual Phenomena campaign for the Jovian satellites and improved results for the 2009 events

Author

Morgado, B., Vieira-Martins, R., Assafin, M., Dias-Oliveira, A., Machado, D. I., Camargo, J. I. B., Malacarne, M., Sfair, R., Winter, O. C., Braga-Ribas, F., Benedetti-Rossi, G., Boldrin, L. A., Camargo, B. C. B., Gaspar, H. S., Gomes-Júnior, A. R., Miranda, J. O., de Santana, T., and Trabuco, L. L.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Progress in astrometry and orbital modelling of planetary moons in the last decade enabled better determinations of their orbits. These studies need accurate positions spread over extended periods. We present the results of the 2014-2015 Brazilian campaign for 40 mutual events from 47 observed light curves by the Galilean satellites plus one eclipse of Amalthea by Ganymede. We also reanalysed and updated results for 25 mutual events observed in the 2009 campaign. All telescopes were equipped with narrow-band filters centred at 889 nm with a width of 15 nm to eliminate the scattered light from Jupiter. The albedos' ratio was determined using images before and after each event. We simulated images of moons, umbra, and penumbra in the sky plane, and integrated their fluxes to compute albedos, simulate light curves and fit them to the observed ones using a chi-square fitting procedure. For that, we used the complete version of the Oren-Nayer reflectance model. The relative satellite positions mean uncertainty was 11.2 mas ($\sim$35 km) and 10.1 mas ($\sim$31 km) for the 2014-2015 and 2009 campaigns respectively. The simulated and observed \textsc{ascii} light curve files are freely available in electronic form at the \textit{Natural Satellites DataBase} (NSDB). The 40/25 mutual events from our 2014-2015/2009 campaigns represent a significant contribution of 17%/15% in comparison with the PHEMU campaigns lead by the IMCCE. Besides that, our result for the eclipse of Amalthea is only the 4$^{th}$ such measurement ever published after the three ones observed by the 2014-2015 international PHEMU campaign. Our results are suitable for new orbital/ephemeris determinations for the Galilean moons and Amalthea., Comment: 14 pages, 8 figures and 5 tables

Published
2019
Full Text
View/download PDF

4. The trans-Neptunian object (84922) 2003 VS2 through stellar occultations

Author

Benedetti-Rossi, Gustavo, Santos-Sanz, P., Ortiz, J. L., Assafin, M., Sicardy, B., Morales, N., Vieira-Martins, R., Duffard, R., Braga-Ribas, F., Rommel, F. L., Camargo, J. I. B., Desmars, J., Colas, A. F., Vachier, F., Alvarez-Candal, Fernández-Valenzuela, E., Almenares, L., Artola, R., Baum, T. -P., Behrend, R., Bérard, D., Bianco, F., Brosch, N., Ceretta, A., Colazo, C. A., Gomes-Junior, A. R., Ivanov, V. D., Jehin, E., Kaspi, S., Lecacheux, J., Maury, A., Melia, R., Moindrot, S., Morgado, B., Opitom, C., Peyrot, A., Pollock, J., Pratt, A., Roland, S., Spagnotto, J., Tancredi, G., Teng, J. -P., Cacella, P., Emilio, M., Feys, F., Gil-Hutton, R., Jacques, C., Machado, D. I., Malacarne, M., Manulis, I., Milone, A. C., Rojas, G., and Sfair, R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present results from three world-wide campaigns that resulted in the detections of two single-chord and one multi-chord stellar occultations by the Plutino object (84922) 2003~VS$_2$. From the single-chord occultations in 2013 and 2014 we obtained accurate astrometric positions for the object, while from the multi-chord occultation on November 7th, 2014, we obtained the parameters of the best-fitting ellipse to the limb of the body at the time of occultation. We also obtained short-term photometry data for the body in order to derive its rotational phase during the occultation. The rotational light curve present a peak-to-peak amplitude of 0.141 $\pm$ 0.009 mag. This allows us to reconstruct the three-dimensional shape of the body, with principal semi-axes $a = 313.8 \pm 7.1$ km, $b = 265.5^{+8.8}_{-9.8}$ km, and $c = 247.3^{+26.6}_{-43.6}$ km, which is not consistent with a Jacobi triaxial equilibrium figure. The derived spherical volume equivalent diameter of $548.3 ^{+29.5}_{-44.6}$ km is about 5\% larger than the radiometric diameter of 2003~VS$_2$ derived from Herschel data of $523 \pm 35$ km, but still compatible with it within error bars. From those results we can also derive the geometric albedo ($0.123 ^{+0.015}_{-0.014}$) and, under the assumption that the object is a Maclaurin spheroid, the density $\rho = 1400^{+1000}_{-300}$ for the plutino. The disappearances and reappearances of the star during the occultations do not show any compelling evidence for a global atmosphere considering a pressure upper limit of about 1 microbar for a pure nitrogen atmosphere, nor secondary features (e.g. rings or satellite) around the main body., Comment: 22 pages, 14 figures, 1 appendix

Published
2019
Full Text
View/download PDF

5. First stellar occultation by the Galilean moon Europa and upcoming events between 2019 and 2021

Author

Morgado, B., Benedetti-Rossi, G., Gomes-Júnior, A. R., Assafin, M., Lainey, V., Vieira-Martins, R., Camargo, J. I. B., Braga-Ribas, F., Boufleur, R. C., Fabrega, J., Machado, D. I., Maury, A., Trabuco, L. L., de Barros, J. R., Cacella, P., Crispim, A., Jaques, C., Navas, G. Y., Pimentel, E., Rommel, F. L., de Santana, T., Schoenell, W., Sfair, R., and Winter, O. C.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Context. Bright stellar positions are now known with an uncertainty below 1 mas thanks to Gaia DR2. Between 2019-2020, the Galactic plane will be the background of Jupiter. The dense stellar background will lead to an increase in the number of occultations, while the Gaia DR2 catalogue will reduce the prediction uncertainties for the shadow path. Aims. We observed a stellar occultation by the Galilean moon Europa (J2) and propose a campaign for observing stellar occultations for all Galilean moons. Methods. During a predicted period of time, we measured the light flux of the occulted star and the object to determine the time when the flux dropped with respect to one or more reference stars, and the time that it rose again for each observational station. The chords obtained from these observations allowed us to determine apparent sizes, oblatness, and positions with kilometre accuracy. Results. We present results obtained from the first stellar occultation by the Galilean moon Europa observed on 2017 March 31. The apparent fitted ellipse presents an equivalent radius of 1561.2 $\pm$ 3.6 km and oblatenesses 0.0010 $\pm$ 0.0028. A very precise Europa position was determined with an uncertainty of 0.8 mas. We also present prospects for a campaign to observe the future events that will occur between 2019 and 2021 for all Galilean moons. Conclusions. Stellar occultation is a suitable technique for obtaining physical parameters and highly accurate positions of bright satellites close to their primary. A number of successful events can render the 3D shapes of the Galilean moons with high accuracy. We encourage the observational community (amateurs included) to observe the future predicted events., Comment: 10 pages, 16 figures, 4 tables, A&A Letter doi:10.1051/0004-6361/201935500

Published
2019
Full Text
View/download PDF

6. APPROX -- Mutual approximations between the Galilean moons. The 2016-2018 observational campaign

Author

Morgado, B., Vieira-Martins, R., Assafin, M., Machado, D. I., Camargo, J. I. B., Sfair, R., Malacarne, M., Braga-Ribas, F., Robert, V., Bassallo, T., Benedetti-Rossi, G., Boldrin, L. A., Borderes-Motta, G., Camargo, B. C. B., Crispim, A., Dias-Oliveira, A., Gomes-Júnior, A. R., Lainey, V., Miranda, J. O., Moura, T. S., Ribeiro, F. K., de Santana, T., Santos-Filho, S., Trabuco, L. L., Winter, O. C., and Yamashita, T. A. R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The technique of mutual approximations accurately gives the central instant at the maximum apparent approximation of two moving natural satellites in the sky plane. This can be used in ephemeris fitting to infer the relative positions between satellites with high precision. Only the mutual phenomena -- occultations and eclipses -- may achieve better results. However, mutual phenomena only occur every six years in the case of Jupiter. Mutual approximations do not have this restriction and can be observed at any time along the year as long as the satellites are visible. In this work, we present 104 central instants determined from the observations of 66 mutual approximations between the Galilean moons carried out at different sites in Brazil and France during the period 2016--2018. For 28 events we have at least two independent observations. All telescopes were equipped with a narrow-band filter centred at 889 nm with a width of 15 nm to eliminate the scattered light from Jupiter. The telescope apertures ranged between 25--120 cm. For comparison, the precision of the positions obtained with classical CCD astrometry is about 100 mas, for mutual phenomena it can achieve 10 mas or less and the average internal precision obtained with mutual approximations was 11.3 mas. This new kind of simple, yet accurate observations can significantly improve the orbits and ephemeris of Galilean satellites and thus be very useful for the planning of future space missions aiming at the Jovian system., Comment: 12 pages, 7 figures

Published
2018
Full Text
View/download PDF

7. A ring system detected around the Centaur (10199) Chariklo

Author

Braga-Ribas, F., Sicardy, B., Ortiz, J. L., Snodgrass, C., Roques, F., Vieira-Martins, R., Camargo, J. I. B., Assafin, M., Duffard, R., Jehin, E., Pollock, J., Leiva, R., Emilio, M., Machado, D. I., Colazo, C., Lellouch, E., Skottfelt, J., Gillon, M., Ligier, N., Maquet, L., Benedetti-Rossi, G., Gomes Jr, A. Ramos, Kervella, P., Monteiro, H., Sfair, R., Moutamid, M. El, Tancredi, G., Spagnotto, J., Maury, A., Morales, N., Gil-Hutton, R., Roland, S., Ceretta, A., Gu, S. -h., Wang, X. -b., Harpsøe, K., Rabus, M., Manfroid, J., Opitom, C., Vanzi, L., Mehret, L., Lorenzini, L., Schneiter, E. M., Melia, R., Lecacheux, J., Colas, F., Vachier, F., Widemann, T., Almenares, L., Sandness, R. G., Char, F., Perez, V., Lemos, P., Martinez, N., Jørgensen, U. G., Dominik, M., Roig, F., Reichart, D. E., LaCluyze, A. P., Haislip, J. B., Ivarsen, K. M., Moore, J. P., Frank, N. R., and Lambas, D. G.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Until now, rings have been detected in the Solar System exclusively around the four giant planets. Here we report the discovery of the first minor-body ring system around the Centaur object (10199) Chariklo, a body with equivalent radius 124$\pm$9 km. A multi-chord stellar occultation revealed the presence of two dense rings around Chariklo, with widths of about 7 km and 3 km, optical depths 0.4 and 0.06, and orbital radii 391 and 405 km, respectively. The present orientation of the ring is consistent with an edge-on geometry in 2008, thus providing a simple explanation for the dimming of Chariklo's system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partially composed of water ice. These rings may be the remnants of a debris disk, which were possibly confined by embedded kilometre-sized satellites.

Published
2014
Full Text
View/download PDF

9. Refined physical parameters for Chariklo’s body and rings from stellar occultations observed between 2013 and 2020

Author

Morgado, B. E., primary, Sicardy, B., additional, Braga-Ribas, F., additional, Desmars, J., additional, Gomes-Júnior, A. R., additional, Bérard, D., additional, Leiva, R., additional, Ortiz, J. L., additional, Vieira-Martins, R., additional, Benedetti-Rossi, G., additional, Santos-Sanz, P., additional, Camargo, J. I. B., additional, Duffard, R., additional, Rommel, F. L., additional, Assafin, M., additional, Boufleur, R. C., additional, Colas, F., additional, Kretlow, M., additional, Beisker, W., additional, Sfair, R., additional, Snodgrass, C., additional, Morales, N., additional, Fernández-Valenzuela, E., additional, Amaral, L. S., additional, Amarante, A., additional, Artola, R. A., additional, Backes, M., additional, Bath, K.-L., additional, Bouley, S., additional, Buie, M. W., additional, Cacella, P., additional, Colazo, C. A., additional, Colque, J. P., additional, Dauvergne, J.-L., additional, Dominik, M., additional, Emilio, M., additional, Erickson, C., additional, Evans, R., additional, Fabrega-Polleri, J., additional, Garcia-Lambas, D., additional, Giacchini, B. L., additional, Hanna, W., additional, Herald, D., additional, Hesler, G., additional, Hinse, T. C., additional, Jacques, C., additional, Jehin, E., additional, Jørgensen, U. G., additional, Kerr, S., additional, Kouprianov, V., additional, Levine, S. E., additional, Linder, T., additional, Maley, P. D., additional, Machado, D. I., additional, Maquet, L., additional, Maury, A., additional, Melia, R., additional, Meza, E., additional, Mondon, B., additional, Moura, T., additional, Newman, J., additional, Payet, T., additional, Pereira, C. L., additional, Pollock, J., additional, Poltronieri, R. C., additional, Quispe-Huaynasi, F., additional, Reichart, D., additional, de Santana, T., additional, Schneiter, E. M., additional, Sieyra, M. V., additional, Skottfelt, J., additional, Soulier, J. F., additional, Starck, M., additional, Thierry, P., additional, Torres, P. J., additional, Trabuco, L. L., additional, Unda-Sanzana, E., additional, Yamashita, T. A. R., additional, Winter, O. C., additional, Zapata, A., additional, and Zuluaga, C. A., additional

Published
2021
Full Text
View/download PDF

12. The first observed stellar occultations by the irregular satellite Phoebe (Saturn IX) and improved rotational period

Author

Gomes-Júnior, A R, primary, Assafin, M, additional, Braga-Ribas, F, additional, Benedetti-Rossi, G, additional, Morgado, B E, additional, Camargo, J I B, additional, Vieira-Martins, R, additional, Desmars, J, additional, Sicardy, B, additional, Barry, T, additional, Campbell-White, J, additional, Fernández-Lajús, E, additional, Giles, D, additional, Hanna, W, additional, Hayamizu, T, additional, Hirose, T, additional, De Horta, A, additional, Horvat, R, additional, Hosoi, K, additional, Jehin, E, additional, Kerr, S, additional, Machado, D I, additional, Mammana, L A, additional, Maybour, D, additional, Owada, M, additional, Rahvar, S, additional, and Snodgrass, C, additional

Published
2019
Full Text
View/download PDF

13. The Trans-Neptunian Object (84922) 2003 VS2 through Stellar Occultations

Author

Benedetti-Rossi, Gustavo, primary, Santos-Sanz, P., additional, Ortiz, J. L., additional, Assafin, M., additional, Sicardy, B., additional, Morales, N., additional, Vieira-Martins, R., additional, Duffard, R., additional, Braga-Ribas, F., additional, Rommel, F. L., additional, Camargo, J. I. B., additional, Desmars, J., additional, Colas, A. F., additional, Vachier, F., additional, Alvarez-Candal, A., additional, Fernández-Valenzuela, E., additional, Almenares, L., additional, Artola, R., additional, Baum, T.-P., additional, Behrend, R., additional, Bérard, D., additional, Bianco, F. B., additional, Brosch, N., additional, Ceretta, A., additional, Colazo, C. A., additional, Gomes-Junior, A. R., additional, Ivanov, V. D., additional, Jehin, E., additional, Kaspi, S., additional, Lecacheux, J., additional, Maury, A., additional, Melia, R., additional, Moindrot, S., additional, Morgado, B., additional, Opitom, C., additional, Peyrot, A., additional, Pollock, J., additional, Pratt, A., additional, Roland, S., additional, Spagnotto, J., additional, Tancredi, G., additional, Teng, J.-P., additional, Cacella, P., additional, Emilio, M., additional, Feys, F., additional, Gil-Hutton, R., additional, Jacques, C., additional, Machado, D. I., additional, Malacarne, M., additional, Manulis, I., additional, Milone, A. C., additional, Rojas, G., additional, and Sfair, R., additional

Published
2019
Full Text
View/download PDF

14. First stellar occultation by the Galilean moon Europa and upcoming events between 2019 and 2021

Author

Morgado, B., primary, Benedetti-Rossi, G., additional, Gomes-Júnior, A. R., additional, Assafin, M., additional, Lainey, V., additional, Vieira-Martins, R., additional, Camargo, J. I. B., additional, Braga-Ribas, F., additional, Boufleur, R. C., additional, Fabrega, J., additional, Machado, D. I., additional, Maury, A., additional, Trabuco, L. L., additional, de Barros, J. R., additional, Cacella, P., additional, Crispim, A., additional, Jaques, C., additional, Navas, G. Y., additional, Pimentel, E., additional, Rommel, F. L., additional, de Santana, T., additional, Schoenell, W., additional, Sfair, R., additional, and Winter, O. C., additional

Published
2019
Full Text
View/download PDF

15. APPROX – mutual approximations between the Galilean moons: the 2016–2018 observational campaign

Author

Morgado, B, primary, Vieira-Martins, R, additional, Assafin, M, additional, Machado, D I, additional, Camargo, J I B, additional, Sfair, R, additional, Malacarne, M, additional, Braga-Ribas, F, additional, Robert, V, additional, Bassallo, T, additional, Benedetti-Rossi, G, additional, Boldrin, L A, additional, Borderes-Motta, G, additional, Camargo, B C B, additional, Crispim, A, additional, Dias-Oliveira, A, additional, Gomes-Júnior, A R, additional, Lainey, V, additional, Miranda, J O, additional, Moura, T S, additional, Ribeiro, F K, additional, Santana, T de, additional, Santos-Filho, S, additional, Trabuco, L L, additional, Winter, O C, additional, and Yamashita, T A R, additional

Published
2018
Full Text
View/download PDF

16. The PHEMU15 catalogue and astrometric results of the Jupiter's Galilean satellite mutual occultation and eclipse observations made in 2014–2015

Author

Saquet, E, primary, Emelyanov, N, additional, Robert, V, additional, Arlot, J-E, additional, Anbazhagan, P, additional, Baillié, K, additional, Bardecker, J, additional, Berezhnoy, A A, additional, Bretton, M, additional, Campos, F, additional, Capannoli, L, additional, Carry, B, additional, Castet, M, additional, Charbonnier, Y, additional, Chernikov, M M, additional, Christou, A, additional, Colas, F, additional, Coliac, J-F, additional, Dangl, G, additional, Dechambre, O, additional, Delcroix, M, additional, Dias-Oliveira, A, additional, Drillaud, C, additional, Duchemin, Y, additional, Dunford, R, additional, Dupouy, P, additional, Ellington, C, additional, Fabre, P, additional, Filippov, V A, additional, Finnegan, J, additional, Foglia, S, additional, Font, D, additional, Gaillard, B, additional, Galli, G, additional, Garlitz, J, additional, Gasmi, A, additional, Gaspar, H S, additional, Gault, D, additional, Gazeas, K, additional, George, T, additional, Gorda, S Y, additional, Gorshanov, D L, additional, Gualdoni, C, additional, Guhl, K, additional, Halir, K, additional, Hanna, W, additional, Henry, X, additional, Herald, D, additional, Houdin, G, additional, Ito, Y, additional, Izmailov, I S, additional, Jacobsen, J, additional, Jones, A, additional, Kamoun, S, additional, Kardasis, E, additional, Karimov, A M, additional, Khovritchev, M Y, additional, Kulikova, A M, additional, Laborde, J, additional, Lainey, V, additional, Lavayssiere, M, additional, Le Guen, P, additional, Leroy, A, additional, Loader, B, additional, Lopez, O C, additional, Lyashenko, A Y, additional, Lyssenko, P G, additional, Machado, D I, additional, Maigurova, N, additional, Manek, J, additional, Marchini, A, additional, Midavaine, T, additional, Montier, J, additional, Morgado, B E, additional, Naumov, K N, additional, Nedelcu, A, additional, Newman, J, additional, Ohlert, J M, additional, Oksanen, A, additional, Pavlov, H, additional, Petrescu, E, additional, Pomazan, A, additional, Popescu, M, additional, Pratt, A, additional, Raskhozhev, V N, additional, Resch, J-M, additional, Robilliard, D, additional, Roschina, E, additional, Rothenberg, E, additional, Rottenborn, M, additional, Rusov, S A, additional, Saby, F, additional, Saya, L F, additional, Selvakumar, G, additional, Signoret, F, additional, Slesarenko, V Y, additional, Sokov, E N, additional, Soldateschi, J, additional, Sonka, A, additional, Soulie, G, additional, Talbot, J, additional, Tejfel, V G, additional, Thuillot, W, additional, Timerson, B, additional, Toma, R, additional, Torsellini, S, additional, Trabuco, L L, additional, Traverse, P, additional, Tsamis, V, additional, Unwin, M, additional, Abbeel, F Van Den, additional, Vandenbruaene, H, additional, Vasundhara, R, additional, Velikodsky, Y I, additional, Vienne, A, additional, Vilar, J, additional, Vugnon, J-M, additional, Wuensche, N, additional, and Zeleny, P, additional

Published
2017
Full Text
View/download PDF

17. APPROX – mutual approximations between the Galilean moons: the 2016–2018 observational campaign.

Author

Morgado, B, Vieira-Martins, R, Assafin, M, Machado, D I, Camargo, J I B, Sfair, R, Malacarne, M, Braga-Ribas, F, Robert, V, Bassallo, T, Benedetti-Rossi, G, Boldrin, L A, Borderes-Motta, G, Camargo, B C B, Crispim, A, Dias-Oliveira, A, Gomes-Júnior, A R, Lainey, V, Miranda, J O, and Moura, T S

Subjects
GALILEAN satellites, ASTRONOMICAL observations, TELESCOPES, DATA analysis, GANYMEDE (Satellite)
Abstract

The technique of mutual approximations accurately gives the central instant of the maximum apparent approximation of two moving natural satellites in the plane of the sky. This can be used in ephemeris fitting to infer the relative positions of satellites with high precision. Only mutual phenomena – occultations and eclipses – can achieve better results. However, mutual phenomena only occur every six years in the case of Jupiter. Mutual approximations do not have this restriction and can be observed at any time in the year as long as the satellites are visible. In this work, we present 104 central instants determined from the observations of 66 mutual approximations between the Galilean moons carried out at different sites in Brazil and France during the period 2016–2018. For 28 events, we have at least two independent observations. All telescopes were equipped with a narrow-band filter centred at 889 nm with a width of 15 nm to eliminate the scattered light from Jupiter. The telescope apertures ranged between 25 and 120 cm. For comparison, the precision of the positions obtained with classical CCD astrometry is about 100 mas, for mutual phenomena it can be 10 mas or less, and the average internal precision obtained with mutual approximations is 11.3 mas. This new type of simple, yet accurate, observations can significantly improve the orbits and ephemeris of Galilean satellites and thus it can be very useful for the planning of future space missions to the Jovian system. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

18. Compilation of analytical methods to characterize and determine chitosan, and main applications of the polymer in food active packaging

Author

Lago Crespo, Miguel Ángel, Rodríguez Bernaldo de Quirós, Ana Isabel, Sendón García, Raquel, Sanches Silva, A.T., Costa, H.S., Sánchez Machado, D. I., López Cervantes, Jaime, Soto Valdez, H., Aurrekoetxea, G.P., Angulo, Inmaculada, Paseiro Losada, Perfecto Miguel, and Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía

Subjects
Revisión, Chitosan, Characterization, Chitin, Review, Quitina, Caracterización, Quitosano, Materiales para el envasado alimentario, Food Packaging Materials, Segurança Alimentar, Applications, Analytical Techniques, Técnicas analíticas
Abstract

Antimicrobial films for food packaging applications have received increasing attention from the industry in recent years. Due to their exceptional properties, such as non-toxicity, biodegradability, antimicrobial characteristics, and biocompatibility, chitosan has proven useful for the development of active materials. This review aims to provide anoverview of the main techniques used for the characterization of chitin and chitosan, including Fourier transforminfrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, UV spectrophotometry, viscosimetry, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), titrations, scanning electron microscopy (SEM) and size exclusion chromatography (SEC) among others. In addition, the main applications of the polymer in food packaging are also reported En los últimos años los films antimicrobianos han recibido una gran atención por parte de la industria para su aplicación en el envasado alimentario. Debido a sus excepcionales propiedades, no-tóxico, biodegradable, características antimicrobianas y biocompatible, el quitosano ha demostrado ser útil para el desarrollo de materiales activos. Este artículo de revisión tiene por objeto proporcionar una visión general de las principales técnicas usadas para la caracterización de quitina y quitosano incluidas la espectroscopia infrarroja (FTIR), la espectroscopia RMN de 1H y 13C, la espectrofotometría UV, viscosimetría, análisis elemental, difracción de rayos-X (XRD), análisis termogravimétrico (TGA), titulaciones, microscopía electrónica de barrido (SEM) y cromatografía de exclusión por tamaños (SEC)entre otras. Además, se describen las principales aplicaciones del polímero en el envasado de los alimentos This work was funded under the Project no. 95935 from FONCICYT C002-2008-1/ALA 127 249 SI

Published
2011

19. Compilation of analytical methods to characterize and determine chitosan, and main applications of the polymer in food active packaging

Author

Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía, Lago Crespo, Miguel Ángel, Rodríguez Bernaldo de Quirós, Ana Isabel, Sendón García, Raquel, Sanches Silva, A.T., Costa, H.S., Sánchez Machado, D. I., López Cervantes, Jaime, Soto Valdez, H., Aurrekoetxea, G.P., Angulo, Inmaculada, Paseiro Losada, Perfecto Miguel, Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía, Lago Crespo, Miguel Ángel, Rodríguez Bernaldo de Quirós, Ana Isabel, Sendón García, Raquel, Sanches Silva, A.T., Costa, H.S., Sánchez Machado, D. I., López Cervantes, Jaime, Soto Valdez, H., Aurrekoetxea, G.P., Angulo, Inmaculada, and Paseiro Losada, Perfecto Miguel

Abstract

Antimicrobial films for food packaging applications have received increasing attention from the industry in recent years. Due to their exceptional properties, such as non-toxicity, biodegradability, antimicrobial characteristics, and biocompatibility, chitosan has proven useful for the development of active materials. This review aims to provide anoverview of the main techniques used for the characterization of chitin and chitosan, including Fourier transforminfrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, UV spectrophotometry, viscosimetry, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), titrations, scanning electron microscopy (SEM) and size exclusion chromatography (SEC) among others. In addition, the main applications of the polymer in food packaging are also reported, En los últimos años los films antimicrobianos han recibido una gran atención por parte de la industria para su aplicación en el envasado alimentario. Debido a sus excepcionales propiedades, no-tóxico, biodegradable, características antimicrobianas y biocompatible, el quitosano ha demostrado ser útil para el desarrollo de materiales activos. Este artículo de revisión tiene por objeto proporcionar una visión general de las principales técnicas usadas para la caracterización de quitina y quitosano incluidas la espectroscopia infrarroja (FTIR), la espectroscopia RMN de 1H y 13C, la espectrofotometría UV, viscosimetría, análisis elemental, difracción de rayos-X (XRD), análisis termogravimétrico (TGA), titulaciones, microscopía electrónica de barrido (SEM) y cromatografía de exclusión por tamaños (SEC)entre otras. Además, se describen las principales aplicaciones del polímero en el envasado de los alimentos

Published
2011

20. Evaluación físico-química de aceite pigmentado obtenido de la cabeza de camarón

Author

Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía, Núñez Gastélum, J. A., Sánchez Machado, D. I., López Cervantes, J., Paseiro Losada, Perfecto Miguel, Sendón García, Raquel, Sanches Silva, A.T., Costa, H.S., Aurrekoetxea, G.P., Angulo, Inmaculada, Soto Valdez, H., Universidade de Santiago de Compostela. Departamento de Química Analítica, Nutrición e Bromatoloxía, Núñez Gastélum, J. A., Sánchez Machado, D. I., López Cervantes, J., Paseiro Losada, Perfecto Miguel, Sendón García, Raquel, Sanches Silva, A.T., Costa, H.S., Aurrekoetxea, G.P., Angulo, Inmaculada, and Soto Valdez, H.

Abstract

En este trabajo se presenta el análisis proximal, caracterización físico-química, perfil de ácidos grasos y contenido de astaxantina en aceite pigmentado aislado por fermentación láctica de los residuos de camarón. Los lípidos son los componentes mayoritarios (95%). El índice de saponificación es 178.62 mg KOH/g, el de yodo 139.8 cg yodo/g, y los peróxidos no fueron detectados. La densidad y la viscosidad fueron de 0.92 mg/ml y 64 centipoises, respectivamente. Los ácidos grasos en mayor cantidad fueron el linoleico (C18:2n6), oleico (C18:1n9) y palmítico (C16:0). El ácido eicosapentaenoico (C20:5n3, EPA) y el docosahexaenoico (C22:6n3, DHA) suman el 9% del total. El contenido promedio de astaxantina fue de 2.72 mg/g base seca. El aceite pigmentado es una fuente dietética de nutrientes con alto valor como la astaxantina, In this work the proximal analysis, physicochemical characterization, fatty acid profile and astaxanthin content of pigmented oil obtained by fermentation shrimp heads are presented. Lipids are the major components in the oil (95%). The saponification number is 178.62 mg KOH/g, iodine value 139.8 cg iodine/g, and the peroxide value was not detected. Density and viscosity were 0.92 mg/ml and 64 centipoises, respectively. The highest contents of fatty acids were linoleic (C18:2n6), oleic (C18:1n9) and palmitic (C16:0). Eicosapentaenoic acid (C20:5n3, EPA) and docosahexaenoic acid (C22:6n3, DHA) account for 9% of the total. The content of astaxanthin was 2.72 mg/g dry weight. The pigmented oil is a dietary source of nutrients with high value such as astaxanthin

Published
2011

21. A ring system detected around the Centaur (10199) Chariklo

Author

Braga-Ribas, F., primary, Sicardy, B., additional, Ortiz, J. L., additional, Snodgrass, C., additional, Roques, F., additional, Vieira-Martins, R., additional, Camargo, J. I. B., additional, Assafin, M., additional, Duffard, R., additional, Jehin, E., additional, Pollock, J., additional, Leiva, R., additional, Emilio, M., additional, Machado, D. I., additional, Colazo, C., additional, Lellouch, E., additional, Skottfelt, J., additional, Gillon, M., additional, Ligier, N., additional, Maquet, L., additional, Benedetti-Rossi, G., additional, Gomes, A. Ramos, additional, Kervella, P., additional, Monteiro, H., additional, Sfair, R., additional, Moutamid, M. El, additional, Tancredi, G., additional, Spagnotto, J., additional, Maury, A., additional, Morales, N., additional, Gil-Hutton, R., additional, Roland, S., additional, Ceretta, A., additional, Gu, S.-h., additional, Wang, X.-b., additional, Harpsøe, K., additional, Rabus, M., additional, Manfroid, J., additional, Opitom, C., additional, Vanzi, L., additional, Mehret, L., additional, Lorenzini, L., additional, Schneiter, E. M., additional, Melia, R., additional, Lecacheux, J., additional, Colas, F., additional, Vachier, F., additional, Widemann, T., additional, Almenares, L., additional, Sandness, R. G., additional, Char, F., additional, Perez, V., additional, Lemos, P., additional, Martinez, N., additional, Jørgensen, U. G., additional, Dominik, M., additional, Roig, F., additional, Reichart, D. E., additional, LaCluyze, A. P., additional, Haislip, J. B., additional, Ivarsen, K. M., additional, Moore, J. P., additional, Frank, N. R., additional, and Lambas, D. G., additional

Published
2014
Full Text
View/download PDF

22. Ultra-high pressure LC for astaxanthin determination in shrimp by-products and active food packaging

Author

Sanches-Silva, A., primary, Ribeiro, T., additional, Albuquerque, T. G., additional, Paseiro, P., additional, Sendón, R., additional, de Quirós, A. Bernaldo, additional, López-Cervantes, J., additional, Sánchez-Machado, D. I., additional, Soto Valdez, H., additional, Angulo, I., additional, Aurrekoetxea, G. P., additional, and Costa, H. S., additional

Published
2012
Full Text
View/download PDF

32. Ultra-high pressure LC for astaxanthin determination in shrimp by-products and active food packaging.

Author

Sanches‐Silva, A., Ribeiro, T., Albuquerque, T. G., Paseiro, P., Sendón, R., Quirós, A. Bernaldo, López‐Cervantes, J., Sánchez‐Machado, D. I., Soto Valdez, H., Angulo, I., Aurrekoetxea, G. P., and Costa, H. S.

Abstract

ABSTRACT Nowadays, there is increasing interest in natural antioxidants from food by-products. Astaxanthin is a potent antioxidant and one of the major carotenoids in crustaceans and salmonids. An ultra-high pressure liquid chromatographic method was developed and validated for the determination of astaxanthin in shrimp by-products, and its migration from new packaging materials to food simulants was also studied. The method uses an UPLC® BEH guard-column (2.1 × 5 mm, 1.7 µm particle size) and an UPLC® BEH analytical column (2.1 × 50 mm, 1.7 µm particle size). Chromatographic separation was achieved using a programmed gradient mobile phase consisting of (A) acetonitrile-methanol (containing 0.05 m ammonium acetate)-dichloromethane (75:20:5, v/v/v) and (B) ultrapure water. This method was evaluated with respect to validation parameters such as linearity, precision, limit of detection, limit of quantification and recovery. Low-density polyethylene films were prepared with different amounts of the lipid fraction of fermented shrimp waste by extrusion, and migration was evaluated into food simulants (isooctane and ethanol 95%, v/v). Migration was not detected under the tested conditions. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

33. Evaluación físico-química de aceite pigmentado obtenido de la cabeza de camarón.

Author

Núñez-Gastélum, J. A., Sánchez-Machado, D. I., López-Cervantes, J., Paseiro-Losada, P., Sendón, R., Sanches-Silva, A. T., Costa, H. S., Aurrekoetxea, G. P., Angulo, I., and Soto-Valdez, H.

Subjects
*FATS & oils analysis, *SHRIMPS, *FATTY acid content of food, *ASTAXANTHIN, *SAPONIFICATION
Abstract

In this work the proximal analysis, physicochemical characterization, fatty acid profile and astaxanthin content of pigmented oil obtained by fermentation shrimp heads are presented. Lipids are the major components in the oil (95%). The saponification number is 178.62 mg KOH/g, iodine value 139.8 cg iodine/g, and the peroxide value was not detected. Density and viscosity were 0.92 mg/ml and 64 centipoises, respectively. The highest contents of fatty acids were linoleic (C18:2n6), oleic (C18:1n9) and palmitic (C16:0). Eicosapentaenoic acid (C20:5n3, EPA) and docosahexaenoic acid (C22:6n3, DHA) account for 9% of the total. The content of astaxanthin was 2.72 mg/g dry weight. The pigmented oil is a dietary source of nutrients with high value such as astaxanthin. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

34. IMPROVING TEXTURAL CHARACTERISTICS OF TORTILLAS BY ADDING GUMS DURING EXTRUSION TO OBTAIN NIXTAMALIZED CORN FLOUR.

Author

PLATT-LUCERO, L. C., RAMIREZ-WONG, B., TORRES-CHÁVEZ, P. I., LÓPEZ-CERVANTES, J., SÁNCHEZ-MACHADO, D. I., REYES-MORENO, C., MILÁN-CARRILLO, J., and MORALES-ROSAS, I.

Subjects
CORN, FLOUR, XANTHAN gum, VISCOELASTICITY, SENSORY evaluation
Abstract

Whole white corn was ground, and lime, water and xanthan gum (XG, 0.5% w/w), carboxymethylcellulose (CMC, 0.5% w/w), guar gum (GG, 0.5% w/w) or a gums mix (XG, 0.25% w/w; CMC, 0.15% w/w; GG, 0.10% w/w) were added. Blends were extruded, dried and ground to obtain nixtamalized corn flour (ENCF), and they were used to make tortillas. The particle size distribution, particle size index, water absorption capacity (WAC) and water absorption index (WAI) were determined in flour; moisture content and viscoelastic characteristics (G′, G′′, tan δ) were determined in corn masa; tortillas were made, and texture (cutting force and rollability) and sensory evaluation were carried out. ENCF with XG and gums mix had the highest WAC, and tortillas were softer (33%) than tortillas from ENCF without gums. Corn masa viscoelasticity (tan δ) correlated negatively with tortilla firmness (r = − 0.84). Corn tortillas made with XG and gums mix had acceptable organoleptic characteristics. PRACTICAL APPLICATION The extrusion process allows the using of the whole corn to make tortillas and reduce processing costs and the contaminant effluents (cooking liquor). The addition of a mix of gums during extrusion makes the corn masa retain more water and modify its rheological properties, improving masa handling characteristics and tortilla textural quality. The evaluation of masa viscoelasticity with the dynamic method makes it possible to differentiate corn masas and to select the best treatments. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

35. HPLC method validation for measurement of sulforaphane level in broccoli by-products.

Author

Campas-Baypoli, O. N., Sánchez-Machado, D. I., Bueno-Solano, C., Ramírez-Wong, B., and López-Cervantes, J.

Abstract

A simple and specific analytical method was developed and tested for the determination of sulforaphane in broccoli by-products. The method includes the optimization of the conversion of glucoraphanin to sulforaphane, followed by purification of extracts using solid-phase extraction and high-performance liquid chromatography (HPLC) analysis. The response surface methodology was used to find optimum conditions for the preparation and purification procedure. Chromatographic conditions for reversed-phase HPLC with UV photodiode array detection were as follows: column, Exil ODS C18, 25 × 0.46 cm, 5 μm; column temperature, 36°C; mobile phase, a 30 : 70 (v/v) mixture of acetonitrile:water; flow rate, 0.6 mL/min. The detection wavelength was UV 202 nm. Under these conditions, excellent linearity was obtained ( r2 = 1), and the overall recovery was 97.5 and 98.1% for fresh florets and lyophilized florets, respectively. The precision results showed that the relative standard deviation of the repeatability for florets fresh and lyophilized was 3.0 and 4.0%, respectively. Sulforaphane contents were determined in the edible portion of fresh broccoli, and broccoli crop remains. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2010
Full Text
View/download PDF

36. Determination of the uronic acid composition of seaweed dietary fibre by HPLC.

Author

Sánchez-Machado, D. I., López-Cervantes, J., López-Hernández, J., Paseiro-Losada, P., and Simal-Lozano, J.

Abstract

A high-performance liquid chromatographic (HPLC) method is described for determination of the ratio of β- d-mannuronic acid to α- l-guluronic acid (M/G ratio) in dietary fibre of edible seaweeds. Total dietary fibre (TDF) content was determined gravimetrically. The TDF fraction was hydrolysed with 12 m and 1 m H2SO4, then neutralized with AG 4 × 4 resin. The uronic acids were separated in a Tracer Extrasil SAX 5 µm column (25 cm × 4 mm) at 35°C, with 2 m m KH2PO4 containing 5% methanol as mobile phase at a flow rate of 1.5 mL/min. The detection wavelength was UV 210 nm. The chromatographic identifications of β- d-mannuronic acid and α- l-guluronic acid were confirmed by liquid chromatography-mass spectrometry (LC-MS). The method precision was 1.4% for β- d-mannuronic acid and 3.5% for α- l-guluronic acid. The method was used to determine M/G ratio in canned seaweeds ( Saccorhiza polyschides and Himanthalia elongata) and in dried seaweeds ( H. elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp. and Porphyra sp.). Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2004
Full Text
View/download PDF

37. CHARACTERIZATION OF CHITOSAN MEANT FOR ANTIMICROBIAL FOOD PACKAGING

Author

Sendón, R., Rodríguez-Bernaldo Quirós, A., Bueno-Solano, C., Pereira, D., Sanches-Silva, A., Costa, H. S., Sánchez-Machado, D. I., Soto Valdez, H., Angulo, I., Aurrekoetxea, G. P., Jaime López-Cervantes, and Paseiro, P.

Subjects
Segurança Alimentar, macromolecular substances
Abstract

Chitosan (CAS nº 9012-76-4) is a natural polysaccharide obtained by the partial deacetylation of chitin. It is a linear polymer of β (1-4) 2-acetamido-2-deoxy-D-glucose and 2-amino-2-deoxy-D-glucose in different proportions. Chitin is the most abundant polysaccharide after cellulose and the main source is the shells of crustaceans. It has been demonstrated that some important properties are directly related to the antimicrobial activity of chitosan. Some of these properties are the molecular weight (Mw), the degree of polymerisation (DP) and the degree of deacetylation (DD). In this work several analytical techniques (FTIR (Fourier-transform Infrared Spectroscopy), NMR (Nuclear Magnetic Resonance Spectroscopy) and SEM (Scanning Electron Microscopy)) were attempted to characterize two different samples obtained from shrimp waste. It can be concluded that sample 1 should be more suitable to be added as an active agent to a film. This work was funded under Project ‘Preparation of active packaging with antioxidant and antimicrobial activity based on astaxanthin and chitosan’ (PAPAAABAC, in Spanish PEACAABAQ) no. 95935 from FONCICYT C002-2008-1/ALA – 127 249

41. A ring system detected around the Centaur (10199) Chariklo

Author

Lellouch, E., Dominik, M., Maquet, L., Char, F., Wang, X.-b., Reichart, D. E., Mehret, L., Martinez, N., Schneiter, E. M., Morales, N., Moore, J. P., Perez, V., Ligier, N., LaCluyze, A. P., Duffard, R., Ramos Gomes, A., Gil-Hutton, R., Roig, F., Colas, F., Snodgrass, C., Almenares, L., Vieira-Martins, R., Lecacheux, J., Spagnotto, J., Roques, F., Gillon, M., Manfroid, J., Sandness, R. G., Assafin, M., Vanzi, L., Lemos, P., Opitom, C., Skottfelt, J., Widemann, T., El Moutamid, M., Emilio, M., Harpsøe, K., Lambas, D. G., Haislip, J. B., Sfair, R., Jørgensen, U. G., Rabus, M., Monteiro, H., Braga-Ribas, F., Frank, N. R., Ceretta, A., Lorenzini, L., Camargo, J. I. B., Maury, A., Colazo, C., Ortiz, J. L., Vachier, F., Jehin, E., Benedetti-Rossi, G., Machado, D. I., Roland, S., Sicardy, B., Melia, R., Gu, S.-h., Pollock, J., Tancredi, G., Leiva, R., Kervella, P., and Ivarsen, K. M.

Subjects
Astrophysics::Earth and Planetary Astrophysics, 7. Clean energy
Abstract

Until now, rings have been detected in the Solar System exclusively around the four giant planets. Here we report the discovery of the rst minor-body ring system around the Centaur object (10199) Chariklo, a body with equivalent radius 124±9 km. A multi-chord stellar occultation revealed the presence of two dense rings around Chariklo, with widths of about 7 km and 3 km, optical depths 0.4 and 0.06, and orbital radii 391 and 405 km, respectively. The present orientation of the ring is consistent with an edge-on geometry in 2008, thus providing a simple explanation for the dimming of Chariklo's system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partially composed of water ice. These rings may be the remnants of a debris disk, which were possibly con ned by embedded kilometre-sized satellites.

42. Determination of α-tocopherol in shrimp waste to evaluate its potential to produce active packaging

Author

Sanches-Silva, A., Costa, H. S., Bueno-Solano, C., Sendón, R., Sánchez-Machado, D. I., Soto Valdez, H., Colín-Chávez, C., INMACULADA ANGULO, Aurrekoetxea, G. P., Paseiro, P., and López-Cervantes, J.

Subjects
Segurança Alimentar
Abstract

The possibility of using the lipid fraction from fermented shrimp waste as a source of natural α-tocopherol to produce packaging with antioxidant properties was evaluated. A fast reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method coupled with a diode array detector was developed to determine α-tocopherol in the lipid fraction of shrimp waste. The α-tocopherol level found using acetonitrile as extraction solvent was 50.5 mg/100 g sample. This work was funded under Project ‘Preparation of active packaging with antioxidant and antimicrobial activity based on astaxanthin and chitosan’ (PAPAAABAC, in Spanish PEACAABAQ) no. 95935 from FONCICYT C002-2008-1/ALA – 127 249.

45. Quantification of organic acids in fermented shrimp waste by HPLC

Author

Sánchez-Machado, D. I., Jaime López-Cervantes, and Martínez-Cruz, O.

Subjects
lcsh:Food processing and manufacture, lcsh:TP368-456, lactic acid fermentation, lcsh:Biotechnology, lcsh:TP248.13-248.65, fungi, organic acids, food and beverages, HPLC, shrimp waste
Abstract

This work describes a simple, rapid, and reliable HPLC method for the determination of organic acids in fermented shrimp waste. Lactic, acetic and citric acids were quantified by HPLC with UV detection, on a 250×4.6 mm Extrasil ODS 5-μm column, mobile phase was ultrapure water adjusted with metaphosphoric acid to pH=2.1, flow rate 0.6 mL/min, column temperature 30 °C, and detection wavelength 210 nm. Under these conditions, the recovery (97.5 %) and the method repeatability (RSD=6.2 %) for lactic acid were of satisfying quality. Organic acids can preserve the quality and nutritive value of fermented shrimp waste.

47. Refined physical parameters for Chariklo’s body and rings from stellar occultations observed between 2013 and 2020

Author

Morgado, B. E., Sicardy, B., Braga-Ribas, F., Desmars, J., Gomes-Júnior, A. R., Bérard, D., Leiva, R., Ortiz, J. L., Vieira-Martins, R., Benedetti-Rossi, G., Santos-Sanz, P., Camargo, J. I. B., Duffard, R., Rommel, F. L., Assafin, M., Boufleur, R. C., Colas, F., Kretlow, M., Beisker, W., Sfair, R., Snodgrass, C., Morales, N., Fernández-Valenzuela, E., Amaral, L. S., Amarante, A., Artola, R. A., Backes, M., Bath, K.-L., Bouley, S., Buie, M. W., Cacella, P., Colazo, C. A., Colque, J. P., Dauvergne, J.-L., Dominik, M., Emilio, M., Erickson, C., Evans, R., Fabrega-Polleri, J., Garcia-Lambas, D., Giacchini, B. L., Hanna, W., Herald, D., Hesler, G., Hinse, T. C., Jacques, C., Jehin, E., Jørgensen, U. G., Kerr, S., Kouprianov, V., Levine, S. E., Linder, T., Maley, P. D., Machado, D. I., Maquet, L., Maury, A., Melia, R., Meza, E., Mondon, B., Moura, T., Newman, J., Payet, T., Pereira, C. L., Pollock, J., Poltronieri, R. C., Quispe-Huaynasi, F., Reichart, D., de Santana, T., Schneiter, E. M., Sieyra, M. V., Skottfelt, J., Soulier, J. F., Starck, M., Thierry, P., Torres, P. J., Trabuco, L. L., Unda-Sanzana, E., Yamashita, T. A. R., Winter, O. C., Zapata, A., Zuluaga, C. A., Morgado, B. E., Sicardy, B., Braga-Ribas, F., Desmars, J., Gomes-Júnior, A. R., Bérard, D., Leiva, R., Ortiz, J. L., Vieira-Martins, R., Benedetti-Rossi, G., Santos-Sanz, P., Camargo, J. I. B., Duffard, R., Rommel, F. L., Assafin, M., Boufleur, R. C., Colas, F., Kretlow, M., Beisker, W., Sfair, R., Snodgrass, C., Morales, N., Fernández-Valenzuela, E., Amaral, L. S., Amarante, A., Artola, R. A., Backes, M., Bath, K.-L., Bouley, S., Buie, M. W., Cacella, P., Colazo, C. A., Colque, J. P., Dauvergne, J.-L., Dominik, M., Emilio, M., Erickson, C., Evans, R., Fabrega-Polleri, J., Garcia-Lambas, D., Giacchini, B. L., Hanna, W., Herald, D., Hesler, G., Hinse, T. C., Jacques, C., Jehin, E., Jørgensen, U. G., Kerr, S., Kouprianov, V., Levine, S. E., Linder, T., Maley, P. D., Machado, D. I., Maquet, L., Maury, A., Melia, R., Meza, E., Mondon, B., Moura, T., Newman, J., Payet, T., Pereira, C. L., Pollock, J., Poltronieri, R. C., Quispe-Huaynasi, F., Reichart, D., de Santana, T., Schneiter, E. M., Sieyra, M. V., Skottfelt, J., Soulier, J. F., Starck, M., Thierry, P., Torres, P. J., Trabuco, L. L., Unda-Sanzana, E., Yamashita, T. A. R., Winter, O. C., Zapata, A., and Zuluaga, C. A.

48. CHARACTERIZATION OF CHITOSAN MEANT FOR ANTIMICROBIAL FOOD PACKAGING.

Author

SENDÓN, R., DE QUIRÓS1, A. RODRÍGUEZ-BERNALDO, BUENO-SOLANO, C., PEREIRA, D., SANCHES-SILVA, A., COSTA, H. S., SÁNCHEZ-MACHADO, D. I., VALDEZ, H. SOTO, ANGULO, I., AURREKOETXEA, G. P., LÓPEZ-CERVANTES, J., and PASEIRO, P.

Subjects
*FOOD packaging, *ANTI-infective agents, *CHITOSAN, *POLYSACCHARIDES, *DEACETYLATION, *CHITIN, *MOLECULAR weights
Abstract

Chitosan (CAS n. 9012-76-4) is a natural polysaccharide obtained by the partial deacetylation of chitin. It is a linear polymer of b (1-4) 2-acetamido-2-deoxy-D-glucose and 2-amino-2-deoxy-D-glucose in different proportions. Chitin is the most abundant polysaccharide after cellulose and the main source is the shells of crustaceans. It has been demonstrated that some important properties are directly related to the antimicrobial activity of chitosan. Some of these properties are the molecular weight (Mw), the degree of polymerisation (DP) and the degree of deacetylation (DD). In this work several analytical techniques (FTIR (Fourier-transform Infrared Spectroscopy), NMR (Nuclear Magnetic Resonance Spectroscopy) and SEM (Scanning Electron Microscopy)) were attempted to characterize two different samples obtained from shrimp waste. It can be concluded that sample 1 should be more suitable to be added as an active agent to a film. [ABSTRACT FROM AUTHOR]

Published
2011

49. DETERMINATION OF α-TOCOPHEROL IN SHRIMP WASTE TO EVALUATE ITS POTENTIAL TO PRODUCE ACTIVE PACKAGING.

Author

SANCHES-SILVA, A., COSTA, H. S., BUENO-SOLANO, C., SENDÓN, R., SANCHEZ-MACHADO, D. I., VALDEZ, H. SOTO, COLÍN-CHÁVEZ4, C., ANGULO, AURREKOETXEA, G. P., PASEIRO, P., and LÓPEZ-CERVANTES, J.

Subjects
*VITAMIN E, *SHRIMPS, *FOOD packaging, *LIPIDS, *ANTIOXIDANTS, *LIQUID chromatography, *ACETONITRILE
Abstract

The possibility of using the lipid fraction from fermented shrimp waste as a source of natural a-tocopherol to produce packaging with antioxidant properties was evaluated. A fast reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method coupled with a diode array detector was developed to determine α-tocopherol in the lipid fraction of shrimp waste. The α-tocopherol level found using acetonitrile as extraction solvent was 50.5 mg/100 g sample, indicating. [ABSTRACT FROM AUTHOR]

Published
2011

50. Production method for electrospun chitosan-based membranes.

Author

Sánchez-Machado DI, López-Cervantes J, Hernández-Ruiz KL, Yépiz-Muñóz JE, Rodríguez-Anaya LZ, and González-Galaviz JR

Abstract

Electrospinning can be used to prepare membranes with characteristics for biomedical application. In this work, the electrospinning conditions for the fabrication of membranes based on polymers extracted from natural sources such as chitosan and collagen were optimized (injection flow, injection volume, distance from the collector to the neddle, needle size and voltage). Specifically, four formulations were prepared with pure chitosan and mixtures of collagen (purified or hydrolyzed) and agarose. The optimal electrospinning conditions were an injection flow rate of 0.1 ml/h, a 16 G needle, an injection volume of 5 ml, a distance of 8 cm between the needle and the collector, and a voltage of 20 kV. Agarose addition resulted in greater elongation at break and maximum stress, and greater elasticity was observed in the mixture with hydrolyzed collagen. Fiber formation was observed in the structure prepared from chitosan and hydrolyzed collagen. The water holding capacity was greatest in the pure chitosan membranes and the addition of other polymers reduced this property by their interaction. The contributions of this research are as follows:•The electrospinning conditions were the same for the fabrication of membranes from pure chitosan and chitosan mixed with natural polymers.•The mechanical and biological properties of the membranes were improved by the addition of hydrolyzed collagen and agarose.•The addition of hydrolyzed collagen promoted the formation of fibers and porous membranes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2025 The Authors. Published by Elsevier B.V.)

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results