Desalination using electrodialysis as a function of voltage and salt concentration

Electrodialysis is a process that competes with reverse osmosis for desalination and the removal of specific inorganic contaminants. Desalination experiments were carried out on aqueous solutions containing 5 and 10 g/L NaCl to determine the optimum operating conditions of an electrodialysis (ED) system. Further desalination of aqueous solutions containing 1, 5, 10, 20, 25 and 35 g/L NaCl at an optimum applied voltage of 12 V was conducted to determine the influence of initial salt concentration on the desalination process. The possibility of removing fluoride and nitrate from a groundwater containing about 4.3 g/L NaCl, as well as 2.8 and 31.3 mg/L of fluoride and nitrate respectively, as a function of applied voltage was also investigated. A laboratory electrodialysis stack containing seven cation-exchange membranes and six anion-exchange membranes of 56 cm2 effective area was used. From these studies it is demonstrated that electrodialysis is an effective method for the removal of fluoride and nitrate from brackish groundwater and that real groundwater showed a slower desalination behaviour. Fouling of the membranes was observed

Constructing meaning about the delinquency of young girls in public-housing neighbourhoods

UID/SOC/04647/2013 SFRH/BPD/116119/2016Rooted in the theoretical approaches of social ecology and in childhood studies, the Ph.D. research project on which this paper is based aimed to achieve a better understanding of children’s socialization processes in multi-problematic spaces, particularly concerning their involvement in violence and delinquency. A case study based on ethnographic research and child-centred methods was carried out in six public-housing neighbourhoods in Portugal, which were chosen because they had relatively high levels of social deprivation, violence and crime. The specificity of the social group under study—children aged from 6 to 12 years old—and their living conditions, led us to extend the data collected by trying to learn, from the girls, the reasoning and the meanings they assign to their own actions in daily social practices. The intention was to study the features of girls’ socialization in the field through their own accounts of their lives and to examine their perspectives on offending behaviours. The genderized process of social learning in delinquency identified in the girls’ conversation is an important variable, as familial and social experiences tend to facilitate their entry into delinquency. The transmission of delinquent values takes place essentially within the female family circle or via female peers, rather than from the influence of male individuals.authorsversionpublishe

The Relationship Between Parenting and Delinquency: A Meta-analysis

This meta-analysis of 161 published and unpublished manuscripts was conducted to determine whether the association between parenting and delinquency exists and what the magnitude of this linkage is. The strongest links were found for parental monitoring, psychological control, and negative aspects of support such as rejection and hostility, accounting for up to 11% of the variance in delinquency. Several effect sizes were moderated by parent and child gender, child age, informant on parenting, and delinquency type, indicating that some parenting behaviors are more important for particular contexts or subsamples. Although both dimensions of warmth and support seem to be important, surprisingly very few studies focused on parenting styles. Furthermore, fewer than 20% of the studies focused on parenting behavior of fathers, despite the fact that the effect of poor support by fathers was larger than poor maternal support, particularly for sons. Implications for theory and parenting are discussed

The “Invisible” Hispanic? The Representation of Hispanics in Criminal Justice Research: What Do We Know and Where Should We Go?

The size of the Hispanic population in the United States has grown to the point that they now comprise the largest minority group. While much research has been conducted to explore the effects of race and ethnicity on various aspects of the criminal justice system, most of these studies focus on African Americans. The purpose of this study is to assess the representation of Hispanics in criminal justice literature and to summarize the findings. The results suggest that while many studies contained Hispanic subjects, few articles focused specifically on His-panics and fewer articles focused on Hispanic women. When analyzed separately, Hispanics were found to be statistically different from other groups. Much of the Hispanic-focused research centered on drug use, gang involvement, and violence. Given the size and growth of this important group, criminologists must consciously recognize and proactively seek to include the views and experiences of Hispanics in their research