Desenvolvimento e validação de equação para determinação do coeficiente de dispersão longitudinal em rios de médio porte Development and validation of an equation to estimate longitudinal dispersion coefficient in medium-sized rivers

No presente trabalho, desenvolveu-se equação para predição do coeficiente de dispersão longitudinal (D L) em rios de médio porte, com vazões entre 16,20 e 98 m³ s-1, a partir de ensaios experimentais utilizando traçadores fluorescentes. A equação foi deduzida utilizando-se análise dimensional e ajustada aos dados de campo pela técnica de regressão linear múltipla. Em seguida, realizou-se a validação da equação testando-a em outra base de dados, diferente daquela para a qual foi desenvolvida, com vazões entre 19,57 a 48,54 m³s-1. Adicionalmente, foram comparados os desempenhos de outras quatro equações empíricas de predição do D L, utilizando-se três métodos comparativos. A equação desenvolvida apresentou ajuste estatístico adequado e bom resultado, com melhor desempenho geral quando comparada a outras equações propostas na literatura.<br>In this paper, an equation has been developed to estimate the longitudinal dispersion coefficient (D L) in medium-sized rivers, with flow between 16.20 and 98 m³s-1, from experimental tests using fluorescent tracers. The equation was deduced by dimensional analysis and adjusted to the field data by the multiple linear regression technique. Thereafter, the validation of the equation was performed by testing it in another database, which is different from the one it had been developed for, with flow between 19.57 and 48.54 m³s-1. Additionally, the performance of four other empirical equations was compared for D L prediction using three comparative methods. The developed equation showed appropriate statistical adjustment and good result, with better overall performance when compared with other equations proposed in literature

The effect of multilingualism/multiculturalism on personality: no gain without pain for third culture kids?

The present study investigates the link between multilingualism/multiculturalism, acculturation and the personality profile (as measured by the Multicultural Personality Questionnaire) of 79 young London teenagers, half of whom were born abroad and had settled down in London during their childhood 'Third Culture Kids' (TCKs; Pollock & Van Reken, 2001). Statistical analyses revealed that TCKs scored higher on the dimension of Openmindedness and Cultural Empathy and scored lower on Emotional Stability. Language dominance (first language (L1), L1 and one or two other languages (multidominance), or any language which is not the L1 (LX) had a significant effect on the participants' personality profile, with the multidominant group scoring significantly higher on Openmindedness, marginally higher on Cultural Empathy and significantly lower on Emotional Stability than participants dominant in one language only. The number of languages known by participants was also significantly linked to their personality profile, with functional multilinguals scoring significantly higher than incipient bilinguals on Openmindedness, marginally higher on Cultural Empathy and significantly lower on Emotional Stability. These findings confirm that personality is shaped by social and biographical factors. Acculturation is stressful but the experience of having to fit in and being in contact with different languages and cultures strengthens Cultural Empathy and Openmindedness. Adapted from the source documen