8,644 research outputs found
Caracterização do óleo de pinhão-manso (Jatropha curcas L.).
O pinhão manso (Jatropha curcas L.), pertencente a familia Euphorbiaceae, e uma planta nativa da America tropical, naturalizada em partes tropicais e subtropicais da Africa e Asia. Sua distribuição geografica e bastante vasta devido a sua rusticidade, resistencia a longas estiagens, bem como a pragas e doencas, sendo adaptavel a condicoes edafoclimaticas muito variaveis. O fruto de J.curcas contem oleo viscoso que pode ser usado na industria de cosmeticos, como substituto do querosene, e na fabricacao de sabao e combustivel para motores diesel. Este trabalho tem como objetivo caracterizar o oleo de pinhao manso segundo sua composicao quimica e parâmetros fisico-quimicos, tendo em vista sua utilizacao para a producao de biocombustivel..
Gravitational Waves from Wobbling Pulsars
The prospects for detection of gravitational waves from precessing pulsars
have been considered by constructing fully relativistic rotating neutron star
models and evaluating the expected wave amplitude from a galactic source.
For a "typical" neutron matter equation of state and observed rotation rates,
it is shown that moderate wobble angles may render an observable signal from a
nearby source once the present generation of interferometric antennas becomes
operative.Comment: PlainTex, 7 pp. , no figures, IAG/USP Rep. 6
Avaliação fenológica do pinhão manso (Jatropha curcas L.) no MunicÃpio de Teresina-PI.
O pinhão manso (Jatropha curcas L.), também conhecido como pinhão do paraguai, pinhão-de-cerca ou pinhão bravo é uma planta arbórea de pequeno porte, da famÃlia das Euphorbiaceae, originária do México e América Central e que apresenta potencial como uma fonte de óleo não comestÃvel. O conhecimento da fenologia de uma planta possibilita prever a época de reprodução, deciduidade, ciclos de crescimento vegetativo e sua relação com os fatores climáticos, auxiliando operações agrÃcolas como poda, colheita, etc. O presente trabalho foi desenvolvido no Campo Experimental da Embrapa Meio Norte, municÃpio de Teresina-PI. Sortearam-se 21 plantas de pinhão-manso (Jatropha curcas L.) para o acompanhamento mensal da fenologia no perÃodo de janeiro a dezembro de 2007. A intensidade dos eventos fenológicos foi estimada para cada planta, seguindo-se os métodos de Fournier (Fournier, 1976) e o Ãndice de atividade. A queda foliar ocorreu ao longo do ano, com picos no perÃodo seco e chuvoso. Os picos de emissão de flores em Jatropha curcas foi observada nos meses de julho, outubro e novembro. De acordo com o percentual de Fournier os picos de ocorrência de frutos verdes e maduros foram observados nos meses de março a setembro e março a outubro, respectivamente
Language education at the University of Aveiro before and after Bologna: practices and discourses
Higher education plays a fundamental role in the construction of a European
citizenship that demands the development of plurilingual competences.
Although the Bologna Process highlights that development (relating it to
mobility, employability and lifelong learning), language education does not seem
to be a priority in the agenda of higher education institutions (Tudor 2006).In the
context of curricular restructuring required by the Bologna Process, this article
presents a case study of the University of Aveiro (UA), Portugal, which set out to
describe institutional practices and discourses concerning the use and function
of languages in undergraduate and postgraduate education in two academic
years (2002–2003 and 2007–2008, before and after the restructuring). In order to
identify practices, we analysed the programmes of all language courses.This allowed
us to identify the languages and language courses offered, as well as the
degree programmes into which they are integrated. In order to access institutional
discourses, we interviewed seven actors responsible for training and management
at the UA (Rectors, Vice-Rectors, the Head of the Department of Languages
and Cultures, The Erasmus Programme Coordinator, and the President of the
Students’
Union). The results show that the Bologna Process has had a limiting
effect on language education: fewer language courses are offered and fewer
degree
programmes include them. This converges with the institutional actors’
discourses, since they do not recognize the institution’s responsibility to develop
students’ plurilingual competences and tend to value only the instrumental role
of English
As lÃnguas na investigação cientÃfica: práticas e discursos na Universidade de Aveiro
Considerando que Instituições de Ensino Superior são espaços onde o conhecimento cientÃfico é produzido e disseminado, apresenta-se um estudo de caso da Universidade de Aveiro, Portugal, que pretende descrever práticas e discursos institucionais relativamente à utilização das lÃnguas na investigação cientÃfica. Para descrição das práticas, foram recolhidos e analisados Relatórios Anuais das Unidades de Investigação da Universidade de Aveiro. Para acesso aos discursos institucionais, foram entrevistados oito atores institucionais, responsáveis pela investigação cientÃfica e pelo governo e coordenação da instituição. Os resultados apontam para uma convergência entre as práticas investigativas e os discursos institucionais relativamente ao papel e estatuto que as diferentes lÃnguas adquirem na investigação cientÃfica: a lÃngua inglesa surge, tanto nas práticas como nos discursos, como primordial para o processo de internacionalização da ciência; por outro lado, as outras lÃnguas são percecionadas enquanto barreiras a essa internacionalização e ao sucesso cientÃfico-profissional do investigador.Considering Higher Education Institutions as settings where scientific knowledge is
produced and disseminated, a case study with the University of Aveiro, Portugal,
will be presented which aimed at describing institutional practices and discourses
concerning the use of languages in scientific research. In order to identify practices within scientific research, documentary analysis of the Annual Reports of the Research
Units of the University of Aveiro was carried out. In order to access institutional
discourses, eight actors responsible for scientific research and management at the
University of Aveiro were interviewed. The results underline that there is a convergence
between research practices and the institutional discourses concerning the role and
status that different languages have in scientific research: English is, both in practices
and discourses, a primordial asset in science internationalisation process; on the
other hand, other languages are perceived as barriers to that internationalisation
and to researchers’ scientific acknowledgement.Considérant les institutions d’enseignement supérieur comme des espaces où les
connaissances scientifiques sont produites et diffusées, on présentera une étude
de cas au sein de l’Université de Aveiro, Portugal, qui vise à décrire les discours et
les pratiques institutionnels concernant l’utilisation des langues dans la recherche
scientifique. Pour une description des pratiques nous avons recueilli et analysé des
rapports annuels des unités de recherche de l’Université d’Aveiro. Pour accéder aux
discours institutionnels nous avons interrogé huit acteurs institutionnels, responsables
de la recherche scientifique et du gouvernement et de l’institution de coordination.
Les résultats montrent une convergence entre les pratiques d’enquête et les discours
institutionnels concernant le rôle et le statut qu’ acquièrent différentes langues dans
la recherche scientifique: la langue anglaise se positionne, Ã la fois dans la pratique et
dans le discours comme un élément central dans le processus d’internationalisation
de la science; en revanche, les autres langues sont perçues comme des obstacles
à cette internationalisation et au succès scientifique et professionnel du chercheur
As lÃnguas na internacionalização da Universidade de Aveiro
Partindo da análise de documentos que revelam a missão, objectivos e vectores estratégicos da Universidade de Aveiro, apresentamos um estudo com o qual se pretende compreender o papel que
as lÃnguas desempenham nas estratégias de internacionalização definidas pela instituição
Two Kerr black holes with axisymmetric spins: An improved Newtonian model for the head-on collision and gravitational radiation
We present a semi-analytical approach to the interaction of two (originally)
Kerr black holes through a head-on collision process. An expression for the
rate of emission of gravitational radiation is derived from an exact solution
to the Einstein's field equations. The total amount of gravitational radiation
emitted in the process is calculated and compared to current numerical
investigations. We find that the spin-spin interaction increases the emission
of gravitational wave energy up to 0.2% of the total rest mass. We discuss also
the possibility of spin-exchange between the holes.Comment: 8 pages, RevTeX, 2 figures, psbox macro include
Life course path analysis of total and central adiposity throughout adolescence on adult blood pressure and insulin resistance
Background and aim: We aimed to study whether the effect of adolescent adiposity on adult blood pressure and insulin resistance was mediated by adult adiposity.
Methods and results: Data from the EPITeen cohort at 13, 17 and 21 years was used (n = 2211). Sex- and age-specific body mass index z-scores (BMIz) and waist-to-hip ratio (WHR) were used as indicators of total and central adiposity, respectively. Systolic blood pressure (SBP), glucose and insulin were assessed at 21 years and the homeostasis model assessment (HOMA-IR) was used as a marker of insulin resistance. Path analysis was applied to evaluate direct and indirect effects of adiposity (13, 17 and 21y) on adult SBP and HOMA-IR, separately for total and central adiposity and for each outcome. Results are presented as standardized regression coefficients [β (95%CI)]. The total effect of BMIz at 13 years on SBP at 21 years was 0.211 (0.178; 0.244), totally mediated by adult BMIz. Total effect of BMIz 13y on HOMA-IR was 0.248 (0.196; 0.299). Although this effect was mostly mediated by BMIz 21y, an additional direct effect from BMIz 17y was found [β = −0.240 (−0.315; −0.164)]. Central adiposity was also positively associated with SBP and HOMA-IR at 21 years, and the effect of adolescent WHR was totally mediated by adult WHR for both outcomes.
Conclusions: The effect of adolescent adiposity on adult SBP and HOMA-IR was mostly mediated by adult adiposity. However, for HOMA-IR an additional direct effect from total adiposity at 17 years was found.This study was supported by national funding from the Portuguese Foundation for Science and Technology (FCT) within the Epidemiology Research Unit e Institute of Public Health, University of Porto (UID/DTP/047507/2013). Individual grants to JA (SFRH/BD/78153/2011) and to SS (SFRH/BD/81123/2011) by the Portuguese Foundation for Science and Technology e FCT are gratefully acknowledged
Watersheds are Schramm-Loewner Evolution curves
We show that in the continuum limit watersheds dividing drainage basins are
Schramm-Loewner Evolution (SLE) curves, being described by one single parameter
. Several numerical evaluations are applied to ascertain this. All
calculations are consistent with SLE, with ,
being the only known physical example of an SLE with . This lies
outside the well-known duality conjecture, bringing up new questions regarding
the existence and reversibility of dual models. Furthermore it constitutes a
strong indication for conformal invariance in random landscapes and suggests
that watersheds likely correspond to a logarithmic Conformal Field Theory (CFT)
with central charge .Comment: 5 pages and 4 figure
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