Relationship between the DTA peak and phase diagram : symbiosis between a thermodynamic database and a DTA curve

The shape of a differential thermal analysis (DTA) curve depends on the sample and the reference, the heating or cooling rates used in theexperiment as also the thermal resistance to heat ¯ow from the heat source to the cell containing the sample (or the reference), Ra (Rr).Having access to a database that contains the values of the sample heat capacity, Cp, and those of the enthalpy of transformation, H, andcalculating the parameters that depend on the apparatus, the cells and the reference, as well as the heating rate used, it is possible todetermine the T (Ta ÿ Tr) values through the equationTa ÿ Tr RadHdt RrCrdTrdt ÿ RaCadTadtwhere Ca is the heat capacity of the cell sample system and Cb the heat capacity of the cell reference system. The comparison betweenthe calculated and experimental values for T enables an assessment to be made as to whether the modelled parameters are in agreementwith the experimental information. This procedure enables a deeper perception of the thermal analysis in general and of the apparatus usedin particular

Introdução

Um dos principais objetivos do Observatório da Emigração é divulgar os estudos que se vão realizando sobre o tema da emigração portuguesa. É certo que a medição regular dos fluxos, através dos dados estatísticos oficiais, capta já muitas das realidades da emigração. Por isso, o Observatório reúne e divulga os dados estatísticos disponíveis. Porém, as estatísticas oficiais estão longe de estabelecer um retrato rigoroso e aprofundado da emigração. Por um lado, as diferenças de metodologia e de conceitos que estão na base da produção estatística levam a frequentes incoerências entre os dados, quando se trata de perceber as caraterísticas de fluxos concretos. Por outro, os objetivos dos organismos estatísticos oficiais são limitados, não podendo recolher informação que permita responder a todas as inquietações e perguntas que se podem levantar acerca da emigração. Finalmente, a análise de questões mais específicas e finas tende a exigir, não só tratamentos particulares da informação existente, como processos de recolha complementares e dirigidos. O papel dos investigadores é, assim, fundamental quando se trata de conhecer a realidade dos movimentos migratórios, em particular da emigração portuguesa, considerando três dimensões fundamentais: os fluxos em si mesmos, a integração nos países de destino e as práticas transnacionais associadas à relação com Portugal. Para responder a esta necessidade, o Observatório da Emigração tem divulgado regularmente os contributos da investigação. As entrevistas a investigadores e a consulta e divulgação de bibliografia adequada estão entre os principais recursos que tem utilizado. Até à data, muitos foram já os pontos de vista e resultados divulgados, tanto oriundos de investigadores portugueses como estrangeiros, respeitantes quer a estudos efetuados em Portugal, quer aos diversos países de destino. A série de publicações que agora se inicia, acerca do estado da emigração portuguesa, procura satisfazer este objetivo de uma outra forma: divulgando de modo aprofundado os resultados de estudos sobre a emigração portuguesa que tenham coincidido no tempo ou no espaço ou, ainda, incidido sobre conjunturas semelhantes. A reunião dos resultados de estudos independentes numa mesma publicação permite aproximar os seus contributos e complementar abordagens, tornando mais fortes as suas conclusões comuns e destacando as suas diferenças.info:eu-repo/semantics/publishedVersio

Can stigma become a resource? The mobilisation of aesthetic–corporal capital by female immigrant entrepreneurs from Brazil

The proportion and visibility of Brazilian women and particularly the specific images of Brazil and Brazilians in the Portuguese imaginary have contributed to the construction of new versions of stigma and stereotypes surrounding them. Mainstream images of Brazilian women have incorporated prejudices about the sensuality of Creole women who are reminiscent of the Portuguese colonial imaginary. Starting from this stigmatised image, we show how Brazilian women entrepreneurs in the ‘beauty’ business filière reinterpret and mobilise this perceived negative image, transforming it into an added value associated with an ‘aesthetic’ Brazilian body culture. This idea of ‘body’ aesthetics becomes a business resource transformed into aesthetic– corporal capital, a key component of the Brazilian beauty business filière. Empirically, this research is based on qualitative elements, in particular 25 interviews with Brazilian women entrepreneurs of the beauty filière working in Portugal, collected for the project BELTS-W (Brazilian Entrepreneurial Links and Transnational Strategies – Women).This article is an output of the Foundation for Science and Technology (FCT) sponsored project PIHM/GC/0111/2008 and Brazilian Entrepreneurial Links and Transnational Strategies-Women (BELTS-W)

Animal Performance in Pastures of \u3ci\u3ePanicum maximum\u3c/i\u3e cv. IPR 86 Fertilized with Nitrogen

The experiment was carried out at the Experimental Station of the IAPAR in Paranavaí– PR, Brazil, from October 1998 to May 1999 to evaluate the response of crossbred steers grazing pastures of Panicum maximum cv. IPR 86 fertilized with four doses of N (0; 150; 300 and 450 kg.ha-1.year). The grass was grazed according to a rotational grazing system with grazing cycles (GCs) of 40 days (grazing period of 5 days and rest period of 35 days). It was used a randomized complete block design, with split-plots, and two replications per treatment, being the N-doses studied in the main plots and the GCs in the sub-plots. The availability of green leaf-blades increased with the increase of N-doses, resulting in 4.09; 8.18; 11.18; and 13.92 steers.ha-1.day-1 and daily LWG of 2.73; 5.25; 7.40; and 9.24 kg.ha-1 when the pastures were fertilized with 0; 150; 300 and 450 kg N.ha-1, respectively. The efficiency of N-utilization was 3.35; 3.11; and 2.89 kg LWG kg.N-1 when the pastures were fertilized with 150; 300; and 450 kg N.ha-1, respectively

New emigration and Portuguese society: Transnationalism and return

This chapter addresses the theme of transnationalism and return in recent Portuguese emigration, namely the flows that occurred after the turn of the century. It starts with a brief theoretical overview on those topics, which constitute two relatively neglected characteristics of Portuguese emigration. Next, based on a survey carried out in 2014–2015 to more than 6000 recent emigrants, it reveals some of the links that they maintain with their home country, as well as their plans for the future, which include settlement in the destination country, return and re-emigration. Lastly, it examines data on returning emigrants – especially those that returned between 2001 and 2011 – extracted from the 2011 Census. The evidence reveals a significant number of returns, including individuals at both working and retirement ages and at all skill levels, thus exposing the unexpected complexity of movements. The results are based on the research project “Back to the future: new emigration and links with Portuguese society” (REMIGR), which aimed to ascertain the extent and characteristics of the new emigration wave. The project included an overview of emigration and return to and from all regions of the world, as well as case studies in UK, France, Luxembourg, Angola, Mozambique and Brazil.info:eu-repo/semantics/publishedVersio

Prediction of Dry Matter Intake Based on Ruminal Degradation from Milking Cows Grazing Coast-Cross Grass

Dry matter intake (DMI) of coast-cross grazing by crossbred Holstein-Zebu and Zebu lactating cows was calculated using in vitro dry matter digestibility from extrusa (four esophageal fistulated cows) and fecal output estimate with mordent chromium. Pasture was rotationally grazed with three days grazing period and 27 days resting period, adopting a stocking rate of 1.6 and 3.2 cows/ha, during the dry and rainy season respectively. Voluntary DMI was estimated from degradation characteristics using different equations. Predicted coast-cross DMI varied with models. The prediction of tropical forages dry matter intake from equations based in ruminal degradation parameters needs further investigation before being employed in practice