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

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

No abstrac

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

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

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 craniotomy729699705O 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-lasem informaçã

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

Fiber association and network formation in PLA/lignocellulosic fiber composites.

PLA composites were prepared in an internal mixer with a lignocellulosic fiber having relatively large aspect ratio. Fiber content changed between 0 and 60 vol% and the homogenized material was compression molded to 1 mm thick plates. The composites showed anomalous behavior above certain fiber content. Their modulus and especially their strength decreased drastically and modeling also proved the loss of reinforcement at large fiber contents. Micromechanical testing showed that the mechanism of deformation and failure changes at a critical fiber content. Microscopic analysis indi-cated the formation of a network purely from geometrical reasons. The inherent strength of the network is very small because of the weak forces acting among the fibers. This weak inherent strength makes the structure of the composites very sensitive to pro-cessing conditions, and decreases strength, reproducibility as well as reliability