Visible-IR Colors and Lightcurve Analysis of Two Bright TNOs: 1999 TC36 and 1998 SN165

We report on observations of two bright Trans-Neptunian Objects (TNOs) - 1999 TC36 and 1998 SN165}- during two observational campaigns, as part of the Meudon Multicolor Survey of Outer Solar System Objects. V-J color was measured for 1999 TC36 (V-J=2.34+/-0.18), which combined with previous measured colors in the visible, indicate a red reflectivity spectrum at all wavelengths. Photometric V-band lightcurves were taken for both objects over a time span of around 8 hours. We have determined a possible rotational period of P=10.1+/-0.8 h for 1998 SN165, making it the seventh TNO with an estimated period. From its lightcurve variation of Dm=0.151(+0.022/-0.030), we have inferred an asymmetry ratio of a/b >=1.148(+0.024/-0.031). For 1999 TC36, we did not detect any rotational period or periodic signal variation within the uncertainties, but the analysis of its lightcurve hints to a slight systematic magnitude decrease.Comment: Accepted for publication in New Astronomy (13 pages, inc. 4 figures

Transition to turbulence in slowly divergent pipe flow

The results of a combined experimental and numerical study of the flow in slowly diverging pipes are presented. Interestingly, an axisymmetric conical recirculation cell has been observed. The conditions for its existence and the length of the cell are simulated for a range of diverging angles and expansion ratios. There is a critical velocity for the appearance of this state. When the flow rate increases further, a subcritical transition for localized turbulence arises. The transition and relaminarization experiments described here quantify the extent of turbulence. The findings suggest that the transition scenario in slowly diverging pipes is a combination of stages similar to those observed in sudden expansions and in straight circular pipe flow.Comment: 8 pages, 5 figure

The Color Distribution in the Edgeworth-Kuiper Belt

We have started since 1997 the Meudon Multicolor Survey of Outer Solar System Objects with the aim of collecting a large and homogeneous set of color data for Trans-Neptunian and Centaurs objects [...] We have a combined sample of 52 B-R color measurements for 8 Centaurs, 22 Classicals, 13 Plutinos, 8 Scattered objects and 1 object with unidentified dynamical class. This dataset is the largest single and homogeneous published dataset to date [...]. A strong (color) correlation with mean excitation velocity points toward a space weathering/impact origin for the color diversity. However, thorough modeling of the collisional/dynamical environment in the Edgeworth-Kuiper belt needs to be done in order to confirm this scenario. We found also that the Classical TNOs consist in the superposition of two distinct populations: the dynamically Cold Classical TNOs (red colors, low i, small sizes) and the dynamically Hot Classical TNOs (diverse colors, moderate and high i, larger sizes). [...] Our specific observation strategy [...] permitted us to highlight a few objects suspected to have true compositional and/or texture variation on their surfaces. These are 1998 HK151, 1999 DF9, 1999 OY3, 2000 GP183, 2000 OK67, and 2001 KA77 and should be prime targets for further observations [...]. Our survey has also highlighted 1998 SN165 whose colors and dynamical properties puts it in a new dynamical class distinct from the Classicals, its previously assigned dynamical class.Comment: Accepted for publication in Astronomical Journal (38 pages, inc. 11 figures

Visible spectroscopy of the new ESO Large Program on trans-Neptunian objects and Centaurs: final results

A second large programme (LP) for the physical studies of TNOs and Centaurs, started at ESO Cerro Paranal on October 2006 to obtain high-quality data, has recently been concluded. In this paper we present the spectra of these pristine bodies obtained in the visible range during the last two semesters of the LP. We investigate the spectral behaviour of the TNOs and Centaurs observed, and we analyse the spectral slopes distribution of the full data set coming from this LP and from the literature. We computed the spectral slope for each observed object, and searched for possible weak absorption features. A statistical analysis was performed on a total sample of 73 TNOs and Centaurs to look for possible correlations between dynamical classes, orbital parameters, and spectral gradient. We obtained new spectra for 28 bodies, 15 of which were observed for the first time. All the new presented spectra are featureless, including 2003 AZ84, for which a faint and broad absorption band possibly attributed to hydrated silicates on its surface has been reported. The data confirm a wide variety of spectral behaviours, with neutral--grey to very red gradients. An analysis of the spectral slopes available from this LP and in the literature for a total sample of 73 Centaurs and TNOs shows that there is a lack of very red objects in the classical population. We present the results of the statistical analysis of the spectral slope distribution versus orbital parameters. In particular, we confirm a strong anticorrelation between spectral slope and orbital inclination for the classical population. A strong correlation is also found between the spectral slope and orbital eccentricity for resonant TNOs, with objects having higher spectral slope values with increasing eccentricity.Comment: 11 pages, 9 figure

Coordinated thermal and optical observations of Trans-Neptunian object (20000) Varuna from Sierra Nevada

We report on coordinated thermal and optical measurements of trans-Neptunian object (20000) Varuna obtained in January-February 2002, respectively from the IRAM 30-m and IAA 1.5 m telescopes. The optical data show a lightcurve with a period of 3.176+/-0.010 hr, a mean V magnitude of 20.37+/-0.08 and a 0.42+/-0.01 magnitude amplitude. They also tentatively indicate that the lightcurve is asymmetric and double-peaked. The thermal observations indicate a 1.12+/-0.41 mJy flux, averaged over the object's rotation. Combining the two datasets, we infer that Varuna has a mean 1060(+180/-220) km diameter and a mean 0.038(+0.022/-0.010) V geometric albedo, in general agreement with an earlier determination using the same technique.Comment: Accepted for publication in Astronomy & Astrophysics (7 pages, including 3 figures

Alterações neuropsiquiátricas da doença de Parkinson

A Doença de Parkinson atinge hoje aproximadamente 1% da população mundial com mais de 65 anos. São cada vez mais bem conhecidas as manifestações neuropsiquiátricas que se associam à doença e/ou ao tratamento. Pretendemos nesta revisão abordar sumariamente a epidemiologia, fisiopatologia e diagnóstico da Doença de Parkinson, destacando as alterações neuropsiquiátricas: depressão, ansiedade, psicose, demência, perturbações do sono, síndroma de desregulação da dopamina

Processos de mudança no campo da sustentabilidade empresarial e as contribuições dos detentores de capital : um estudo de caso em uma empresa do setor têxtil

Factors with a negative impact on the environment, such as the excessive use of natural resources or global warming, are the basis for adopting more sustainable and environmentally friendly measures. A process of change that does not allow anyone to be left out, neither people nor companies, and that has gained relevance as the latter have come to realize that adopting the path of sustainability could translate into added value. The textile sector,from which reports of efforts in this direction come to us, is an example of this, so, within the scope of an analysis and reflection around the main concepts of sustainability, we will seek to understand the role and contributions of the holders of capital for sustainability. This study explores the role of capital holders in promoting sustainability in business through an exploratory case study conducted at Sourcetextile, a company operating in the textile sector. The results found indicate that Sourcetextile presents a sustainable behavior, based on the three pillars of sustainability, and that this is due to the social and environmental concerns of entrepreneurs, which creates a kind of permanent tension between economic and environmental objectives. and social, without which the company would only be concerned with economic objectives.Resumo: Fatores com impacto negativo no meio ambiente, como o uso excessivo de recursos naturais ou o aquecimento global, estão na base da adoção de medidas mais sustentáveis e amigas ambiente. Um processo de mudança que não permite deixar ninguém de fora, nem pessoas nem empresas, e que foi ganhando relevância à medida que estas últimas foram percebendo que adotar o caminho da sustentabilidade se poderia traduzir em valor acrescentado. O setor têxtil, de onde nos chegam relatos de esforços nesse sentido, é disso exemplo, pelo que, no âmbito de uma análise e reflexão em torno dos principais conceitos da sustentabilidade, vamos procurar perceber o papel e contributos dos detentores do capital para a sustentabilidade empresarial com recurso a um estudo de caso exploratório na Sour cetextile, empresa que opera no setor têxtil. Os resultados encontrados indicam que a Sourcetextile apresenta uma conduta sustentável, com base nos três pilares da sustentabilidade, e que isto se deve às preocupações sociais e ambientais dos empresários, que vai criando como que uma espécie de tensão permanente entre os objetivos económicos e os ambientais e sociais, sem a qual a empresa apenas se preocuparia com os objetivos económicos.info:eu-repo/semantics/publishedVersio

Neptune Trojans and Plutinos: colors, sizes, dynamics, and their possible collisions

Neptune Trojans and Plutinos are two subpopulations of trans-Neptunian objects located in the 1:1 and the 3:2 mean motion resonances with Neptune, respectively, and therefore protected from close encounters with the planet. However, the orbits of these two kinds of objects may cross very often, allowing a higher collisional rate between them than with other kinds of trans-Neptunian objects, and a consequent size distribution modification of the two subpopulations. Observational colors and absolute magnitudes of Neptune Trojans and Plutinos show that i) there are no intrinsically bright (large) Plutinos at small inclinations, ii) there is an apparent excess of blue and intrinsically faint (small) Plutinos, and iii) Neptune Trojans possess the same blue colors as Plutinos within the same (estimated) size range do. For the present subpopulations we analyzed the most favorable conditions for close encounters/collisions and address any link there could be between those encounters and the sizes and/or colors of Plutinos and Neptune Trojans. We also performed a simultaneous numerical simulation of the outer Solar System over 1 Gyr for all these bodies in order to estimate their collisional rate. We conclude that orbital overlap between Neptune Trojans and Plutinos is favored for Plutinos with large libration amplitudes, high eccentricities, and small inclinations. Additionally, with the assumption that the collisions can be disruptive creating smaller objects not necessarily with similar colors, the present high concentration of small Plutinos with small inclinations can thus be a consequence of a collisional interaction with Neptune Trojans and such hypothesis should be further analyzed.Comment: 15 pages, 9 figures, 6 tables, accepted for publication in A&

A novel methodology to assess the relaxation rate of the intervertebral disc by increments on intradiscal pressure

Publicado em "Applied mechanics and materials, vol. 664 (2014) pp 379-383"The Intervertebral Disc (IVD) is subjected to several types of loading during daily routine events. However, the overloading on this structure induces higher Intradiscal Pressure (IDP), which could cause severe damage on its structure. This study describes a new approach to that allows monitorize and pressurize nuclear region of the IVD, with a cartilaginous endplate access, by the insertion of an external fluid, while a Motion Segment (MS-assembly composed by vertebra-disc-vertebra) is compressed at a physiological load. This methodology includes the use of a pneumatic structure that applies a certain pressure on the hydrostatic system, forcing a fluid to enter into the MS through a screw, with a drilled hollow along its entire length. Preliminary results indicated that this methodology presents high potential to efficiently pressurize the IVD, providing a useful tool to better understand the response of this structure under pressure.EC -European Commission(NMP-2009-SMALL-3-CP-FP 246351