Warning system based on theoretical-experimental study of dispersion of soluble pollutants in rivers

Information about capacity of transport and dispersion of soluble pollutants in natural streams are important in the management of water resources, especially in planning preventive measures to minimize the problems caused by accidental or intentional waste, in public health and economic activities that depend on the use of water. Considering this importance, this study aimed to develop a warning system for rivers, based on experimental techniques using tracers and analytical equations of one-dimensional transport of soluble pollutants conservative, to subsidizing the decision-making in the management of water resources. The system was development in JAVA programming language and MySQL database can predict the travel time of pollutants clouds from a point of eviction and graphically displays the temporal distribution of concentrations of passage clouds, in a particular location, downstream from the point of its launch.Informações sobre a capacidade de transporte e dispersão de poluentes solúveis em cursos de água naturais são importantes no gerenciamento dos recursos hídricos, principalmente no planejamento preventivo de medidas que visem a minimizar problemas à saúde pública e às atividades econômicas que dependem do uso da água, ocasionados por despejos acidentais ou intencionais. Considerando tal importância, este trabalho teve como objetivo desenvolver um sistema de alerta para rios, com base em resultados experimentais, utilizando técnicas de traçadores e equações analíticas de transporte unidimensional de poluentes solúveis conservativos, visando a subsidiar a tomada de decisão no gerenciamento dos recursos hídricos. O sistema desenvolvido em linguagem de programação JAVA e banco de dados MySQL permite prever o tempo de percurso da nuvem de poluentes a partir de um ponto de despejo de um poluente e apresenta, graficamente, a distribuição temporal de concentrações da passagem da nuvem, em um determinado local, à jusante do ponto do seu lançamento

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