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2. Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation

Author

Santos-Sanz, P., Ortiz, J. L., Sicardy, B., Popescu, M., Benedetti-Rossi, G., Morales, N., Vara-Lubiano, M., Camargo, J. I. B., Pereira, C. L., Rommel, F. L., Assafin, M., Desmars, J., Braga-Ribas, F., Duffard, R., Oliveira, J. Marques, Vieira-Martins, R., Fernández-Valenzuela, E., Morgado, B. E., Acar, M., Anghel, S., Atalay, E., Ateş, A., Bakış, H., Bakış, V., Eker, Z., Erece, O., Kaspi, S., Kayhan, C., Kilic, S. E., Kilic, Y., Manulis, I., Nedelcu, D. A., Niaei, M. S., Nir, G., Ofek, E., Ozisik, T., Petrescu, E., Satir, O., Solmaz, A., Sonka, A., Tekes, M., Unsalan, O., Yesilyaprak, C., Anghel, R., Berteşteanu, D., Curelaru, L., Danescu, C., Dumitrescu, V., Gherase, R., Hudin, L., Stoian, A-M., Tercu, J. O., Truta, R., Turcu, V., Vantdevara, C., Belskaya, I., Dementiev, T. O., Gazeas, K., Karampotsiou, S., Kashuba, V., Kiss, Cs., Koshkin, N., Kozhukhov, O. M., Krugly, Y., Lecacheux, J., Pal, A., Püsküllü, Ç., Szakats, R., Zhukov, V., Bamberger, D., Mondon, B., Perelló, C., Pratt, A., Schnabel, C., Selva, A., Teng, J. P., Tigani, K., Tsamis, V., Weber, C., Wells, G., Kalkan, S., Kudak, V., Marciniak, A., Ogloza, W., Ozdemir, T., Pakstiene, E., Perig, V., and Zejmo, M.

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

Within our international program to obtain accurate physical properties of trans-Neptunian objects (TNOs) we predicted a stellar occultation by the TNO (38628) Huya of the star Gaia DR2 4352760586390566400 (mG = 11.5 mag.) for March 18, 2019. After an extensive observational campaign, we updated the prediction and it turned out to be favorable to central Europe. Therefore, we mobilized half a hundred professional and amateur astronomers, and the occultation was finally detected from 21 telescopes located at 18 sites. This makes the Huya event one of the best ever observed stellar occultation by a TNO in terms of the number of chords. We determine accurate size, shape, and geometric albedo, and we also provide constraints on the density and other internal properties of this TNO. The 21 positive detections of the occultation by Huya allowed us to obtain well-separated chords which permitted us to fit an ellipse for the limb of the body at the moment of the occultation (i.e., the instantaneous limb) with kilometric accuracy. The projected semi-major and minor axes of the best ellipse fit obtained using the occultation data are (a', b') = (217.6 $\pm$ 3.5 km, 194.1 $\pm$ 6.1 km) with a position angle of the minor axis P' = 55.2 $\pm$ 9.1 degrees. From this fit, the projected area-equivalent diameter is 411.0 $\pm$ 7.3 km. This diameter is compatible with the equivalent diameter for Huya obtained from radiometric techniques (D = 406 $\pm$ 16 km). From this instantaneous limb, we obtained the geometric albedo for Huya (p$\rm_V$ = 0.079 $\pm$ 0.004) and we explored possible 3D shapes and constraints to the mass density for this TNO. We did not detect the satellite of Huya through this occultation, but the presence of rings or debris around Huya is constrained using the occultation data. We also derived an upper limit for a putative Pluto-like global atmosphere of about p$_{\rm surf}$ = 10 nbar., Comment: Accepted for publication in Astronomy & Astrophysics (30-April-2022). 19 pages, 7 figures

Published
2022
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3. The multichord stellar occultation on 2019 October 22 by the trans-Neptunian object (84922) 2003 VS$_2$

Author

Vara-Lubiano, M., Benedetti-Rossi, G., Santos-Sanz, P., Ortiz, J. L., Sicardy, B., Popescu, M., Morales, N., Rommel, F. L., Morgado, B., Pereira, C. L., Álvarez-Candal, A., Fernández-Valenzuela, E., Souami, D., Ilic, D., Vince, O., Bachev, R., Semkov, E., Nedelcu, D. A., Şonka, A., Hudin, L., Boaca, M., Inceu, V., Curelaru, L., Gherase, R., Turcu, V., Moldovan, D., Mircea, L., Predatu, M., Teodorescu, M., Stoian, L., Juravle, A., Braga-Ribas, F., Desmars, J., Duffard, R., Lecacheux, J., Camargo, J. I. B., Assafin, M., Vieira-Martins, R., Pribulla, T., Husárik, M., Sivanič, P., Pal, A., Szakats, R., Kiss, C., Alonso-Santiago, J., Frasca, A., Szabó, G. M., Derekas, A., Szigeti, L., Drozdz, M., Ogloza, W., Skvaruc, J., Ciabattari, F., Delincak, P., Di Marcantonio, P., Iafrate, G., Coretti, I., Baldini, V., Baruffetti, P., Klös, O., Dumitrescu, V., Mikuž, H., and Mohar, A.

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

We predicted, observed, and analyzed the multichord stellar occultation of the Second Gaia Data Release (Gaia DR2) source 3449076721168026624 (m$_v$ = 14.1 mag) by the plutino object 2003 VS$_2$ (hereafter, VS$_2$) on 2019 October 22. We also carried out photometric observations to derive the rotational light curve amplitude and rotational phase of VS$_2$ during the stellar occultation. Combining the results and assuming a triaxial shape, we derived the 3D shape of VS$_2$. Out of the 39 observatories involved in the observational campaign, 12 sites reported a positive detection; this makes it one of the best observed stellar occultations by a TNO so far. We obtained a rotational light curve amplitude of ${\Delta}$m = 0.264 $\pm$ 0.017 mag, a mean area-equivalent diameter of D$_{A_{eq}}$ = 545 $\pm$ 13 km, and a geometric albedo of 0.134 $\pm$ 0.010. The best triaxial shape obtained for VS$_2$ has semiaxes a = 339 $\pm$ 5 km, b = 235 $\pm$ 6 km, and c = 226 $\pm$ 8 km. The derived aspect angle is ${\theta}$ = 59${\deg} \pm$ 2${\deg}$ or its supplementary ${\theta}$ = 121${\deg} \pm$ 2${\deg}$, depending on the north-pole position. The spherical-volume equivalent diameter is D$_{V_{eq}}$ = 524 $\pm$ 7 km. If we consider large albedo patches on its surface, the semi-major axis of the ellipsoid could be ~10 km smaller. These results are compatible with the previous ones determined from the single-chord 2013 and four-chord 2014 stellar occultations and with the effective diameter and albedo derived from Herschel and Spitzer data. They provide evidence that VS$_2$'s 3D shape is not compatible with a homogeneous triaxial body in hydrostatic equilibrium, but it might be a differentiated body and/or might be sustaining some stress. No secondary features related to rings or material orbiting around VS$_2$ were detected.

Published
2022
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4. Photometry of asteroids (5141), (43032), (85953), (259221), and (363599) observed at Pic du Midi Observatory

Author

Dumitru, B. A., Birlan, M., Sonka, A., Colas, F., and Nedelcu, D. A.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

These are the first results of an observational program devoted to the complete physical data of asteroids that could produce or feed meteoroid streams. Our results are based on the optical observation at Pic du Midi observatory in April 6-7, 2016 and January 17-18, 2018. We will present the light curve of asteroid (259221) 2003 BA21, associated with Daytime Sextantids (221 DSX) and November theta Aurigids (390 THA); the light curves and colors of asteroid (363599) 2004 FG11, associated with Daytime zeta Perseids (172 ZPE) as well as g-r and g-i; and the corresponding reflectances for the (85953) 1999 FK21, associated with Daytime eta Sagittariids (100 XSA). We will also present the colors for two additional objects, namely, (5141) Tachibana and (43032) 1999 VR26., Comment: 7 pages 6 figures

Published
2018
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5. Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)

Author

Popescu, M., Licandro, J., Morate, D., de Leon, J., Nedelcu, D. A., Rebolo, R., McMahon, R. G., Gonzalez-Solares, E., and Irwin, M.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE) provide information about the surface composition of about 100,000 minor planets. The resulting visible colors and albedos enabled us to group them in several major classes, which are a simplified view of the diversity shown by the few existing spectra. We performed a serendipitous search in VISTA-VHS observations using a pipeline developed to retrieve and process the data that corresponds to solar system objects (SSo). The colors and the magnitudes of the minor planets observed by the VISTA survey are compiled into three catalogs that are available online: the detections catalog (MOVIS-D), the magnitudes catalog (MOVIS-M), and the colors catalog (MOVIS-C). They were built using the third data release of the survey (VISTA VHS-DR3). A total of 39,947 objects were detected, including 52 NEAs, 325 Mars Crossers, 515 Hungaria asteroids, 38,428 main-belt asteroids, 146 Cybele asteroids, 147 Hilda asteroids, 270 Trojans, 13 comets, 12 Kuiper Belt objects and Neptune with its four satellites. The colors found for asteroids with known spectral properties reveal well-defined patterns corresponding to different mineralogies. The distributions of MOVIS-C data in color-color plots shows clusters identified with different taxonomic types. All the diagrams that use (Y-J) color separate the spectral classes more effectively than the (J-H) and (H-Ks) plots used until now: even for large color errors (<0.1), the plots (Y-J) vs (Y-Ks) and (Y-J) vs (J-Ks) provide the separation between S-complex and C-complex. The end members A, D, R, and V-types occupy well-defined regions., Comment: 19 pages, 16 figures

Published
2016
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6. Spectral properties of the largest asteroids associated with Taurid Complex

Author

Popescu, M., Birlan, M., Nedelcu, D. A., Vaubaillon, J., and Cristescu, C. P.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We obtained spectra of six of the largest asteroids (2201, 4183, 4486, 5143, 6063, and 269690) associated with Taurid complex. The observations were made with the IRTF telescope equipped with the spectro-imager SpeX. Their taxonomic classification is made using Bus-DeMeo taxonomy. The asteroid spectra are compared with the meteorite spectra from the Relab database. Mineralogical models were applied to determine their surface composition. All the spectral analysis is made in the context of the already published physical data. Five of the objects studied in this paper present spectral characteristics similar to the S taxonomic complex. The spectra of ordinary chondrites (spanning H, L, and LL subtypes) are the best matches for these asteroid spectra. {\bf The asteroid} (269690) 1996 RG3 presents a flat featureless spectrum which could be associated to a primitive C-type object. The increased reflectance above 2.1 microns constrains its geometrical albedo to a value around 0.03. While there is an important dynamical grouping among the Taurid Complex asteroids, the spectral data of the largest objects do not support a common cometary origin. Furthermore, there are significant variations between the spectra acquired until now., Comment: Accepted for publication in A&A

Published
2014
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9. CONFERENCE "MODERN TECHNIQUES IN OBSERVATIONAL ASTRONOMY".

Author

BIRLAN, M., NEDELCU, D. A., BADESCU, O., and TURCU, V.

Subjects
*CONFERENCES & conventions, *ASTRONOMY, *SPACE environment, *SPACE debris
Abstract

The article focuses on the "Modern Techniques in Observational Astronomy" conference, from July 1 to 5, 2024, at the Sustainable Development Center, in Romania. It states that the conference aimed to synthesize astronomical observational assets in Romania and officially open the Berthelot astronomical observational facility. It mentions that the event included discussions on various astronomical topics such as space weather, space debris, and satellite risks.

Published
2024

11. Physical properties of the trans-Neptunian object (38628) Huya from a multi-chord stellar occultation

Author

Santos-Sanz, P., primary, Ortiz, J. L., additional, Sicardy, B., additional, Popescu, M., additional, Benedetti-Rossi, G., additional, Morales, N., additional, Vara-Lubiano, M., additional, Camargo, J. I. B., additional, Pereira, C. L., additional, Rommel, F. L., additional, Assafin, M., additional, Desmars, J., additional, Braga-Ribas, F., additional, Duffard, R., additional, Marques Oliveira, J., additional, Vieira-Martins, R., additional, Fernández-Valenzuela, E., additional, Morgado, B. E., additional, Acar, M., additional, Anghel, S., additional, Atalay, E., additional, Ateş, A., additional, Bakiş, H., additional, Bakis, V., additional, Eker, Z., additional, Erece, O., additional, Kaspi, S., additional, Kayhan, C., additional, Kilic, S. E., additional, Kilic, Y., additional, Manulis, I., additional, Nedelcu, D. A., additional, Niaei, M. S., additional, Nir, G., additional, Ofek, E., additional, Ozisik, T., additional, Petrescu, E., additional, Satir, O., additional, Solmaz, A., additional, Sonka, A., additional, Tekes, M., additional, Unsalan, O., additional, Yesilyaprak, C., additional, Anghel, R., additional, Berteşteanu, D., additional, Curelaru, L., additional, Danescu, C., additional, Dumitrescu, V., additional, Gherase, R., additional, Hudin, L., additional, Stoian, A-M., additional, Tercu, J. O., additional, Truta, R., additional, Turcu, V., additional, Vantdevara, C., additional, Belskaya, I., additional, Dementiev, T. O., additional, Gazeas, K., additional, Karampotsiou, S., additional, Kashuba, V., additional, Kiss, Cs., additional, Koshkin, N., additional, Kozhukhov, O. M., additional, Krugly, Y., additional, Lecacheux, J., additional, Pal, A., additional, Püsküllü, Ç., additional, Szakats, R., additional, Zhukov, V., additional, Bamberger, D., additional, Mondon, B., additional, Perelló, C., additional, Pratt, A., additional, Schnabel, C., additional, Selva, A., additional, Teng, J. P., additional, Tigani, K., additional, Tsamis, V., additional, Weber, C., additional, Wells, G., additional, Kalkan, S., additional, Kudak, V., additional, Marciniak, A., additional, Ogloza, W., additional, Özdemir, T., additional, Pakštiene, E., additional, Perig, V., additional, and Żejmo, M., additional

Published
2022
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12. The multichord stellar occultation on 2019 October 22 by the trans-Neptunian object (84922) 2003 VS2

Author

Vara-Lubiano, M., primary, Benedetti-Rossi, G., additional, Santos-Sanz, P., additional, Ortiz, J. L., additional, Sicardy, B., additional, Popescu, M., additional, Morales, N., additional, Rommel, F. L., additional, Morgado, B., additional, Pereira, C. L., additional, Álvarez-Candal, A., additional, Fernández-Valenzuela, E., additional, Souami, D., additional, Ilic, D., additional, Vince, O., additional, Bachev, R., additional, Semkov, E., additional, Nedelcu, D. A., additional, Şonka, A., additional, Hudin, L., additional, Boaca, M., additional, Inceu, V., additional, Curelaru, L., additional, Gherase, R., additional, Turcu, V., additional, Moldovan, D., additional, Mircea, L., additional, Predatu, M., additional, Teodorescu, M., additional, Stoian, L., additional, Juravle, A., additional, Braga-Ribas, F., additional, Desmars, J., additional, Duffard, R., additional, Lecacheux, J., additional, Camargo, J. I. B., additional, Assafin, M., additional, Vieira-Martins, R., additional, Pribulla, T., additional, Husárik, M., additional, Sivanič, P., additional, Pal, A., additional, Szakats, R., additional, Kiss, C., additional, Alonso-Santiago, J., additional, Frasca, A., additional, Szabó, G. M., additional, Derekas, A., additional, Szigeti, L., additional, Drozdz, M., additional, Ogloza, W., additional, Skvarč, J., additional, Ciabattari, F., additional, Delincak, P., additional, Di Marcantonio, P., additional, Iafrate, G., additional, Coretti, I., additional, Baldini, V., additional, Baruffetti, P., additional, Klös, O., additional, Dumitrescu, V., additional, Mikuž, H., additional, and Mohar, A., additional

Published
2022
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13. Energy signature of ton TNT-class impacts: analysis of the 22 December 2018 fireball over Western Pyrenees

Author

Anghel, S, Drolshagen, E, Ott, T, Birlan, M, Colas, F, Nedelcu, D, Koschny, D, Zanda, B, Bouley, S, Jeanne, S, Malgoyre, A, Blanpain, C, Gattacceca, J, Jorda, L, Lecubin, J, Rault, J, Vaubaillon, J, Vernazza, P, Hueso, R, Peña-Asensio, E, Ribas, S, Rimola, A, Sánchez-Lavega, A, Tapia, M, Trigo-Rodriguez, J, Cauhape, P, Davadan, C, Dupouy, P, Herpin, M, Rousseu, D, Tregon, B, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU]Sciences of the Universe [physics]
Abstract

International audience; Abstract The increase in detector sensitivity and availability in the past three decades has allowed us to derive knowledge of the meteoroid flux and impact energy into the Earth’s atmosphere. We present the multi-instrument detected 22 December 2018 fireball over Western Pyrenees, and compare several techniques aiming to obtain a reliable method to be used when measuring impacts of similar scale. From trajectory data alone, we found a bulk density of 3.5 g/cm3 to be the most likely value for the Pyrenean meteoroid. This allowed to further constrain the dynamic mass, which translated into a kinetic energy of 1 ton TNT (4.184 · 109 J). For the second energy derivation, via the fireball’s corrected optical radiation, we obtained a more accurate empirical relation measuring well studied bolides . The result approximates to 1.1 ton TNT, which is notably close to the nominal dynamic result, and agrees with the lower margin of the seismic-based energy estimation, yet way lower than the infrasound estimate. Based on the relation derived in this study, we consider the nominal estimate from both the dynamic and photometric methods to be the most accurate value of deposited energy (1 ton TNT). We show that the combination of these two methods can be used to infer the meteoroid density. Among the methods presented in this paper, we found that the optical energy is the most reliable predictor of impact energy near the ton TNT-scale.

Published
2021
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15. Luminous efficiency of meteors derived from ablation model after assessment of its range of validity

Author

Drolshagen, E., primary, Ott, T., additional, Koschny, D., additional, Drolshagen, G., additional, Vaubaillon, J., additional, Colas, F., additional, Zanda, B., additional, Bouley, S., additional, Jeanne, S., additional, Malgoyre, A., additional, Birlan, M., additional, Vernazza, P., additional, Gardiol, D., additional, Nedelcu, D. A., additional, Rowe, J., additional, Forcier, M., additional, Trigo-Rodriguez, J. M., additional, Peña-Asensio, E., additional, Lamy, H., additional, Ferrière, L., additional, Barghini, D., additional, Carbognani, A., additional, Di Martino, M., additional, Rasetti, S., additional, Valsecchi, G. B., additional, Volpicelli, C. A., additional, Di Carlo, M., additional, Knapic, C., additional, Pratesi, G., additional, Riva, W., additional, Stirpe, G. M., additional, Zorba, S., additional, Hernandez, O., additional, Grandchamps, A., additional, Jehin, E., additional, Jobin, M., additional, King, A., additional, Sanchez-Lavega, A., additional, Toni, A., additional, Rimola, A., additional, and Poppe, B., additional

Published
2021
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16. Luminous efficiency based on FRIPON meteors and limitations of ablation models

Author

Drolshagen, E., primary, Ott, T., additional, Koschny, D., additional, Drolshagen, G., additional, Vaubaillon, J., additional, Colas, F., additional, Zanda, B., additional, Bouley, S., additional, Jeanne, S., additional, Malgoyre, A., additional, Birlan, M., additional, Vernazza, P., additional, Gardiol, D., additional, Nedelcu, D. A., additional, Rowe, J., additional, Forcier, M., additional, Trigo-Rodriguez, J. M., additional, Peña-Asensio, E., additional, Lamy, H., additional, Ferrière, L., additional, Barghini, D., additional, Carbognani, A., additional, Di Martino, M., additional, Rasetti, S., additional, Valsecchi, G. B., additional, Volpicelli, C. A., additional, Di Carlo, M., additional, Knapic, C., additional, Pratesi, G., additional, Riva, W., additional, Stirpe, G. M., additional, Zorba, S., additional, Hernandez, O., additional, Grandchamps, A., additional, Jehin, E., additional, Jobin, M., additional, King, A., additional, Sanchez-Lavega, A., additional, Toni, A., additional, Rimola, A., additional, and Poppe, B., additional

Published
2021
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32. Observational asset for Near-Earth Objects, artificial satellites, and space debris: an assessment of concept

Author

Birlan, M., Plesca, V., Gandescu, C. Hedwig, Nedelcu, D. A., Balan, M., Banica, C., Pandele, C., Sonka, A., Georgescu, T., Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Astronomical Observatory 'Admiral Vasile Urseanu', Bucharest Municipal Museum, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
instrumentation, observations, Near-Earth Object, Physics::Space Physics, space debris, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Near-Earth Objects, artificial satellites and space debris are objects of the Earth-Space-Environment(SEE). New data are required continuously for these objects for improving their ephemerides. In the case of Near Earth Objects optimal periods of observations are sparse over the century and in the order of 10-30 days. It is mandatory to exploit these situations in terms of observations for refine the orbit and for derive their physical properties. For the artificial satellites optical observations should be addressed in order to corroborate telemetry and other observational techniques. An increasing importance is addressed to space debris, which are tremendously increased into the last decade. Their orbital evolution is very sensitive to gravitational harmonics of the Earth, tidal effects of the Moon, Sun and major planets, and to non-gravitational forces. Observational survey is required during their evolution on the orbit but also during their falls through the atmosphere. The article presents the premises of a modern asset which should answer to the problematic of observations of Near-Earth Objects, artificial satellites, and space debris in a paradigm of a mobile system which can be rapidly deployed.

Published
2018

33. Asteroid parent bodies of meteor showers: An update

Author

Dumitru, B. A., Birlan, M., Nedelcu, D. A., Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Subjects
asteroids, minor planets, meteors, meteoroids, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], meteorites
Abstract

International audience; In the previous study, we associated 223 asteroids to 28 meteor showers by using three D-Criteria metrics, our own empirical method of threshold selection and D-parameter uncertainty. The databases used in the simulation were the MPCORB (for asteroids) and IAU Meteor Data Center (for meteor showers) from February 2017. In the present work, we will present an update of our previous study on the new databases (the MPCORB and meteor shower databases form February 2018). In the new simulation, we found 72 additional asteroids that can be associated to 20 meteor showers. By using physical parameters, we found the fast-rotator asteroid 2007RS146

Published
2018

46. Characteristics of biodegradable polymers when subjected to ceramic coatings

Author

Mazurchevici Simona-Nicoleta, Marguta Alina, and Nedelcu Dumitru

Subjects
ceramic coating, biodegradable plastic, ceramic micro particles, structure, thermal behavior, tribology, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

This manuscript highlights the behavior of a biodegradable polymer (Arboblend V2 Nature) coated with three distinct ceramic powders, Cr2O3–chromium oxide thermal spray powder, ZrO2 18TiO2 10Y2O3–zirconia–titania–yttria composite powder and Cr2O3-xSiO2-yTiO2–chromia–silica composite powder. The coated was realized on injected samples by using the Atmospheric Plasma Spray (APS) technique. The current investigation will explain the results related to the surface quality, micro-structure, morphology, mechanical, thermal and tribological properties. Thus, from a structural point of view the most uniform deposition was obtained in the case of composite powder based on zirconia. The thermal behavior of the samples coated with ceramic micro layers achieved stability up to temperatures slightly above 200 °C, pyrolysis taking place around 340 °C. The micro indentation, DMA, and scratch analysis responses were significantly influenced by the crystalline structure of the samples and the presence of the Cr2O3 compound. Based on the increased characteristics of the coated samples the authors of the present paper consider that from parts made of biodegradable polymers and coated with ceramic micro-particles are appropriate for some applications that required harsh operating conditions.

Published
2024
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