RESUMEN
A bibliometric analysis, using the Scopus database as a source, was carried out in order to study the scientific documents published up to 2021 regarding the use of electrodialysis, membrane distillation, and forward osmosis for the removal of heavy metals from wastewater. A total of 362 documents that fulfilled the search criteria were found, and the results from the corresponding analysis revealed that the number of documents greatly increased after the year 2010, although the first document was published in 1956. The exponential evolution of the scientific production related to these innovative membrane technologies confirmed an increasing interest from the scientific community. The most prolific country was Denmark, which contributed 19.3% of the published documents, followed by the two main current scientific superpowers: China and the USA (with 17.4% and 7.5% contributions, respectively). Environmental Science was the most common subject (55.0% of contributions), followed by Chemical Engineering (37.3% of contributions) and Chemistry (36.5% of contribution). The prevalence of electrodialysis over the other two technologies was clear in terms of relative frequency of the keywords. An analysis of the main hot topics identified the main advantages and drawbacks of each technology, and revealed that examples of their successful implementation beyond the lab scale are still scarce. Therefore, complete techno-economic evaluation of the treatment of wastewater polluted with heavy metals via these innovative membrane technologies must be encouraged.
RESUMEN
Resumen Se entiende el temperamento como el conjunto de diferencias individuales en reactividad y autorregulación, manteniéndose relativamente estable a través del tiempo, y siendo influenciado por la herencia, la maduración biológica y el contacto con el ambiente. En el presente estudio se buscó establecer si se dan diferencias en las dimensiones de temperamento de extraversión, afecto negativo y autorregulación según nivel socioeconómico, en niños chilenos asistentes a sala cuna. Se evaluaron 103 niños de ambos sexos, a los 12 y a los 30 meses de edad, con los cuestionarios IBQ-R-VSF y ECBQ-VSF, los cuales respondieron los padres. Los resultados mostraron que entre los 12 y 30 meses la extraversión se mantuvo constante, mientras que las dimensiones de afecto negativo y autorregulación disminuyeron de manera significativa. A los 12 meses los niños de NSE alto mostraron una mayor autorregulación, mientras que a los 30 meses los niños de NSE bajo evidenciaron un mayor afecto negativo. Se discuten los resultados en base a la evidencia encontrada sobre las diferentes realidades en los distintos niveles socioeconómicos.
Abstract Temperament is understood as the set of individual differences in reactivity and self-regulation, considered as stable through time, and influenced by the heritability, the biological maturation, and the interaction with the environment. The aim of this study was to determine if the dimensions of temperament (extraversion, negative affect, and self-regulation) show differences according to socioeconomic status in Chilean children attending to nurseries. For this study, 103 children from both genders were evaluated at 12 and 30 months old, using the IBQ-R-VSF and ECBQ-VSF questionnaires, which were answered by their parent. Results showed that between 12 and 30 months, extraversion remained constant, while the dimensions of negative affect and self-regulation decreased significantly. Children from high socioeconomic status showed higher self-regulation at age of 12 months, while the ones from low socioeconomic status decreased their negative affect at 30 months old. Results are discussed based on evidence about realities from different socioeconomic statuses.