Portuguese Ministers, 1851-1999: Social Background and Paths to Power

Disponível em: http://193.136.113.6/Opac/Pages/Search/Results.aspx?SearchText=UID=bb8aa8d5-c6b6-466a-81bb-fe8a67693cee&DataBase=10449_UNLFCSHThis paper provides an empirical analysis of the impact of regime changes in the composition and patterns of recruitment of the Portuguese ministerial elite throughout the last 150 years. The ‘out-of-type’, violent nature of most regime transformations accounts for the purges in and the extensive replacements of the political personnel, namely of the uppermost officeholders. In the case of Cabinet members, such discontinuities did not imply, however, radical changes in their social profile. Although there were some significant variations, a series of salient characteristics have persisted over time. The typical Portuguese minister is a male in his midforties, of middle-class origin and predominantly urban-born, highly educated and with a state servant background. The two main occupational contingents have been university professors - except for the First Republic (1910-26) - and the military, the latter having only recently been eclipsed with the consolidation of contemporary democracy. As regards career pathways, the most striking feature is the secular trend for the declining role of parliamentary experience, which the democratic regime did not clearly reverse. In this period, a technocratic background rather than political experience has been indeed the privileged credential for a significant proportion of minister

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Dynamics Of Graphene Nanodrums

Recently, it was proposed that graphene sheets deposited on silicon oxide can act as impermeable atomic membranes to standard gases, such as helium, argon, and nitrogen. It is assumed that graphene membrane is clamped over the surface due only to van der Waals forces. The leakage mechanism can be experimentally addressed only indirectly. In this work we have carried out molecular dynamics simulations to study this problem. We have considered nano-containers composed of a chamber of silicon oxide filled with gas and sealed by single and multi-layer graphene membranes. The obtained results are in good qualitative agreement with the experimental data. We observed that the graphene membranes remain attached to the substrate for pressure values up to two times the largest value experimentally investigated. We did not observe any gas leakage through the membrane/substrate interface until the critical limit is reached and then a sudden membrane detachment occurs. © 2011 Materials Research Society.1284173178Novoselov, K.S., Geim, A.K., Morozov, S.V., Jiang, D., Zhang, Y., Dubonos, S.V., Grigorieva, I.V., Firsov, A.A., (2004) Science, 306, p. 666Frank, I.W., Tanenbaum, D.M., Van Der Zande, A.M., McEuen, P.L., (2007) J. Vac. Sci. Technol. B, 25, p. 2558Faccio, R., Denis, P.A., Pardo, H., Goyenola, C., Mombrú, A.W., (2009) J. Phys.: Condens. Matt., 21, p. 285304Geim, A.K., Novoselov, K.S., (2007) Nature Materials, 6, p. 183Cadelano, E., Palla, P.L., Giordano, S., Colombo, L., (2009) Phys. Rev. Lett., 102, p. 235502Lee, C., Wei, X., Kysar, J.W., Hone, J., (2008) Science, 321, p. 385Bunch, J.S., Verbridge, S.S., Alden, J.S., Van Der Zande, A.M., Parpia, J.M., Craighead, H.G., McEuen, P.L., (2008) Nano Lett., 8, pp. 2458-2462MacKerell, A.D., Bashford, D., Bellot, M., Dunbrack, R.L., Evanseck, J., Field, M.J., Fischer, S., Karplus, M., (1998) J. Phys. Chem. B, 102, p. 3586Phillips, J.C., Braun, R., Wang, W., Gumbart, J., Tajkhorshid, E., Villa, E., Chipot, C., Schulten, K., (2005) J. Comput. Chem., 26, p. 1781. , http://www.ks.uiuc.edu/Research/namd/, NAMDStone, J.E., Phillips, J.C., Freddolino, P.L., Hardy, D.J., Trabuco, L.G., Schulten, K., (2007) J. Comput. Chem., 28, p. 2618Brunetto, G., Legoas, S.B., Coluci, V.R., Lucena, L.S., Galvao, D.S., to be publishe

Characterization and thermal behavior of polymer-modified asphalt

A styrene-butadiene-styrene modified asphalt cement was characterized by infrared, differential scanning calorimetry, thermogravimetric analysis and empirical tests such as ring and ball softening point, penetration and elastic recovery. After aging in the rolling thin-film oven, the polymer-modified asphalt presented structural changes relating to oxidation of the material. The infrared spectra showed an increase in hydroxyl groups and the formation of carbonyl compounds and sulphoxides. The percentage of crystallized fraction calculated from differential scanning calorimetry was 0.41%. Thermogravimetric analyses in inert and oxidative atmospheres revealed distinct events during thermal decomposition; the initial activation energies were similar, but changed as the process evolved

Dependência espacial da resistência do solo à penetração e do teor de água do solo sob cultivo contínuo de cana-de-açúcar Spatial variability of soil penetration resistance and soil moisture at different periods of sampling under sugarcane crop

O cultivo intensivo dos solos e a utilização de máquinas e equipamentos pesados promovem a compactação do solo. A resistência do solo à penetração é uma medida que detecta esta compactação, contudo ela é fortemente influenciada pelo teor de água no solo. O objetivo deste trabalho foi avaliar o efeito do teor de água no solo na variabilidade espacial da resistência do solo à penetração em um Latossolo Vermelho distrófico. Uma área de 1ha cultivada há 40 anos com cana-de-açúcar foi amostrada nos pontos de cruzamento de uma malha, com intervalos regulares de 10m, perfazendo um total de 100 pontos. As amostras de solo foram coletadas nas profundidades de 0,00-0,15m, 0,15-0,30m e 0,30-0,45m, 24 e 72 horas após uma chuva de 38mm. Resultados de resistência do solo à penetração indicaram um estado alto de compactação nas duas épocas de amostragem. O teor de água no solo afetou consideravelmente a variabilidade espacial da resistência do solo à penetração e quanto maior o teor de água menor foi a dependência espacial. A malha de amostragem deve ser mais adensada em relação à utilizada neste estudo quando o teor de água no solo for superior ao observado 72 horas após a chuva, a fim de se avaliar a variabilidade espacial para a resistência do solo à penetração.<br>The intensive cultivation of soil and the use of machines and equipment promote soil compaction. Soil penetration resistance is a measure that detects this compaction, nevertheless soil moisture influences hardly on soil penetration resistance. The objective of this work was to evaluate the effect of soil moisture on the spatial variability of soil penetration resistance of an Oxisol. An area cultivated for 40 years with sugarcane was sampled in the crossing points of a regular grid, with 10 m intervals, comprising 100 points. Soil samples were collected at 0.00-0.15m, 0.15-0.30m and 0.30-0.45m depths, 24 and 72 hours after a 38mm precipitation. Soil penetration resistance values indicated that compaction was high at the two sampling periods. Soil moisture influenced the spatial variability of soil penetration resistance and a smaller spatial dependence was related to higher soil moistures. The grid used for the evaluation of soil penetration resistance variability must be closer than the one used for this study when the soil moisture is higher than the moisture observed 72 hours after the precipitation