Fire retardant action of mineral fillers

Endothermically decomposing mineral fillers, such as aluminium or magnesium hydroxide, magnesium carbonate, or mixed magnesium/calcium carbonates and hydroxides, such as naturally occurring mixtures of huntite and hydromagnesite are in heavy demand as sustainable, environmentally benign fire retardants. They are more difficult to deploy than the halogenated flame retardants they are replacing, as their modes of action are more complex, and are not equally effective in different polymers. In addition to their presence (at levels up to 70%), reducing the flammable content of the material, they have three quantifiable fire retardant effects: heat absorption through endothermic decomposition; increased heat capacity of the polymer residue; increased heat capacity of the gas phase through the presence of water or carbon dioxide. These three contributions have been quantified for eight of the most common fire retardant mineral fillers, and the effects on standard fire tests such as the LOI, UL 94 and cone calorimeter discussed. By quantifying these estimable contributions, more subtle effects, which they might otherwise mask, may be identified

Can achievement differentials be explained by social class alone?

This article assesses the importance of social class in explaining differentials in the educational achievements of minority ethnic pupils in England and Wales. It is found to be a key factor for all groups. The analysis finds significant differences between ethnic groups even when pupils from the same social class background are compared. When disparities within ethnic groups are examined, however, it is found that the effect of moving one place down the social class structure is similar for all ethnicities. This leads to the conclusion that social class operates in a similar way for all ethnic groups without a specifically `ethnic effect' that mitigates its impact in certain groups

A craniotomia extremo-lateral: dicas e truques

This article intends to describe in a didactical and practical manner the suboccipital far-lateral craniotomy. This is then basically a descriptive text, divided according to the main stages involved in this procedure, and that describes with details how the authors currently perform this craniotomy.O presente artigo visa descrever de forma didática e prática a realização da craniotomia suboccipital extremo-lateral. Trata-se, portanto, de um texto fundamentalmente descritivo, dividido conforme as principais etapas da realização dessa craniotomia, e que descreve com detalhes a técnica com que o presente grupo de autores evolutivamente veio a realizá-la.Universidade Federal de São Paulo (UNIFESP) Departamento de Neurocirurgia VascularHospital Real e Benemérita Sociedade Portuguesa de Beneficência Instituto de Ciências Neurológicas Laboratório de MicrocirurgiaDepartamento de Neurocirurgia VascularHospital Brigadeiro Departamento de Neurocirurgia VascularUniversity of Florida Department of NeurosurgeryUniversidade Estadual de Campinas Faculdade de Ciências Médicas Departamento de NeurologiaUNIFESP, Depto. de Neurocirurgia VascularSciEL

Ideologies of Exemplary Masculinity in French and British Adventure Novels 1870-1900

No abstrac

Parenting behavior and the risk of becoming a victim and a bully/victim : a meta-analysis study

Objective: Being bullied has adverse effects on children's health. Children's family experiences and parenting behavior before entering school help shape their capacity to adapt and cope at school and have an impact on children's peer relationship, hence it is important to identify how parenting styles and parent–child relationship are related to victimization in order to develop intervention programs to prevent or mitigate victimization in childhood and adolescence. Methods: We conducted a systematic review of the published literature on parenting behavior and peer victimization using MEDLINE, PsychINFO, Eric and EMBASE from 1970 through the end of December 2012. We included prospective cohort studies and cross-sectional studies that investigated the association between parenting behavior and peer victimization. Results: Both victims and those who both bully and are victims (bully/victims) were more likely to be exposed to negative parenting behavior including abuse and neglect and maladaptive parenting. The effects were generally small to moderate for victims (Hedge's g range: 0.10–0.31) but moderate for bully/victims (0.13–0.68). Positive parenting behavior including good communication of parents with the child, warm and affectionate relationship, parental involvement and support, and parental supervision were protective against peer victimization. The protective effects were generally small to moderate for both victims (Hedge's g: range: −0.12 to −0.22) and bully/victims (−0.17 to −0.42). Conclusions: Negative parenting behavior is related to a moderate increase of risk for becoming a bully/victim and small to moderate effects on victim status at school. Intervention programs against bullying should extend their focus beyond schools to include families and start before children enter school

What factors are associated with adolescents\u27 school break time physical activity and sedentary time?

Purpose Adolescents\u27 physical activity levels during school break time are low and understanding correlates of physical activity and sedentary time in this context is important. This study investigated cross-sectional and longitudinal associations between a range of individual, behavioural, social and policy/organisational correlates and objectively measured school break time physical activity and sedentary time.Methods In 2006, 146 adolescents (50% males; mean age = 14.1&plusmn;0.6 years) completed a questionnaire and wore an accelerometer for &ge;3 school days. Time spent engaged in sedentary, light (LPA) and moderate-to-vigorous physical activity (MVPA) during school break times (recess and lunchtime) were calculated using existing cut-points. Measures were repeated in 2008 among 111 adolescents. Multilevel models examined cross-sectional and longitudinal associations.Results Bringing in equipment was cross-sectionally associated with 3.2% more MVPA during break times. Females engaged in 5.1% more sedentary time than males, whilst older adolescents engaged in less MVPA than younger adolescents. Few longitudinal associations were observed. Adolescents who brought sports equipment to school engaged in 7.2% less LPA during break times two years later compared to those who did not bring equipment to school.Conclusion These data suggest that providing equipment and reducing restrictions on bringing in sports equipment to school may promote physical activity during school recess. Strategies targeting females\u27 and older adolescents\u27, in particular, are warranted.<br /

Methane oxidation over zeolite catalysts prepared from geothermal fluids

Colloidal silica extracted from geothermal fluid was used as a reagent to produce zeolite Y with high purity. The characteristics of this sample were compared to a sample prepared with a conventional silica sol, namely Ludox. The two samples were treated with ammonium chloride and calcined to partially convert the samples into an H-form. The Na-FAU and H-FAU zeolites were then loaded with Pd and tested as catalysts in the combustion of methane. X-ray diffraction confirmed the characteristic FAU-type framework in all samples. Experiments showed that after addition of Pd, these zeolites were active catalysts in the complete combustion of methane, where the most active catalysts were those prepared from Na-FAU. These findings support the use of low Si/Al FAU-type frameworks in model studies of engine exhaust emissions abatement. The study further shows that the silica sol extracted from geothermal fluids can be successfully utilised for zeolites synthesis

Social support, stress, health, and academic success in Ghanaian adolescents: A path analysis

The aim of this study is to gain a better understanding of the role psychosocial factors play in promoting the health and academic success of adolescents. A total of 770 adolescent boys and girls in Senior High Schools were randomly selected to complete a self-report questionnaire. School reported latest terminal examination grades were used as the measure of academic success. Structural equation modelling indicated a relatively good fit to the posteriori model with four of the hypothesised paths fully supported and two partially supported. Perceived social support was negatively related to stress and predictive of health and wellbeing but not academic success. Stress was predictive of health but not academic success. Finally, health and wellbeing was able to predict academic success. These findings have policy implications regarding efforts aimed at promoting the health and wellbeing as well as the academic success of adolescents in Ghana. © 2014 The Foundation for Professionals in Services for Adolescents