Simplified Waterproofing of Aerogels

A relatively simple silanization process has been developed for waterproofing or rewaterproofing aerogels, xerogels, and aerogel/tile composites, and other, similar low-density, highly microporous materials. Such materials are potentially attractive for a variety of applications especially for thermal-insulation panels that are required to be thin and lightweight. Unfortunately, such materials are also hydrophilic and tend to collapse after adsorbing water from the air. Hence, an effective means of waterproofing is necessary to enable practical exploitation of aerogels and the like. Older processes for waterproofing aerogels are time-consuming, labor-intensive, and expensive, relative to the present process. Each of the older processes includes a number of different chemical treatment steps, and some include the use of toxic halogenated surface-modifying compounds, pressures as high as hundreds of atmospheres, and/or temperatures as high as 1,000 C

Low-density resin impregnated ceramic article and method for making the same

A low-density resin impregnated ceramic article advantageously employed as a structural ceramic ablator comprising a matrix of ceramic fibers. The fibers of the ceramic matrix are coated with an organic resin film. The organic resin can be a thermoplastic resin or a cured thermosetting resin. In one embodiment, the resin is uniformly distributed within the ceramic article. In a second embodiment, the resin is distributed so as to provide a density gradient along at least one direction of the ceramic article. The resin impregnated ceramic article is prepared by providing a matrix of ceramic fibers; immersing the matrix of ceramic fibers in a solution of a solvent and an organic resin infiltrant; and removing the solvent to form a resin film on the ceramic fibers

Secondary polymer layered impregnated tile

A low density organic polymer impregnated preformed fibrous ceramic article includes a plurality of layers. A front layer includes ceramic fibers or carbon fibers or combinations of ceramic fibers and carbon fibers, and is impregnated with an effective amount of at least one organic polymer. A middle layer includes polymer impregnated ceramic fibers. A back layer includes ceramic fibers or carbon fibers or combinations of ceramic fibers and carbon fibers, and is impregnated with an effective amount of at least one low temperature pyrolyzing organic polymer capable of decomposing without depositing residues

Low Density Resin Impregnated Ceramic Article Having an Average Density of 0.15 to 0.40 G/CC

A low-density resin impregnated ceramic article advantageously employed as a structural ceramic ablator comprising a fired preform of ceramic fibers. The fibers of the ceramic preform are coated with an organic resin film. The organic resin can be a thermoplastic resin or a cured thermosetting resin. In one embodiment, the resin is uniformly distributed within the ceramic article. In a second embodiment, the resin is distributed so as to provide a density gradient along at least one direction of the ceramic article. The resin impregnated ceramic article is prepared by providing a fired preform of ceramic fibers; immersing the preform of ceramic fibers in a solution of a solvent and an organic resin infiltrant; and removing the solvent to form a resin film on the ceramic fibers

Working through whiteness, race and (anti) racism in physical education teacher education

Background: The persistent gaps between a largely white profession and ethnically diverse school populations have brought renewed calls to support teachers' critical engagement with race. Programmes examining the effects of racism have had limited impact on practice, with student teachers responding with either denial, guilt or fear; they also contribute to a deficit view of racialised students in relation to an accepted white ‘norm’, and position white teachers ‘outside’ of race. Recent calls argue for a shift in focus towards an examination of the workings of the dominant culture through a critical engagement with whiteness, positioning white teachers within the processes of racialisation. Teacher educators' roles are central, and yet, while we routinely expect student teachers to reflect critically on issues of social justice, we have been less willing to engage in such work ourselves. This is particularly the case within physical education teacher education (PETE), an overwhelmingly white, embodied space, and where race and racism as professional issues are largely invisible. Purpose: This paper examines the operation of whiteness within PETE through a critical reflection on the three co-authors' careers and experiences working for social justice. The research questions were twofold: How are race, (anti) racism and whiteness constructed through everyday experiences of families, schooling and teacher education? How can collective biography be used to excavate discourses of race, racism and whiteness as the first step towards challenging them? In beginning the process of reflecting on what it means for us ‘to do own work’ in relation to (anti) racism, we examine some of the tensions and challenges for teacher educators in PE attempting to work to dismantle whiteness. Methodology: As co-authors, we engaged in collective biography work – a process in which we reflected upon, wrote about and shared our embodied experiences and memories about race, racism and whiteness as educators working for social justice. Using a critical whiteness lens, these narratives were examined for what they reveal about the collective practices and discourses about whiteness and (anti)racism within PETE. Results: The narratives reveal the ways in which whiteness operates within PETE through processes of naturalisation, ex-denomination and universalisation. We have been educated, and now work within, teacher education contexts where professional discourse about race at best focuses on understanding the racialised ‘other’, and at worse is invisible. By drawing on a ‘racialised other’, deficit discourse in our pedagogy, and by ignoring race in own research on inequalities in PETE, we have failed to disrupt universalised discourses of ‘white-as-norm’, or addressed our own privileged racialised positioning. Reflecting critically on our biographies and careers has been the first step in recognising how whiteness works in order that we can begin to work to disrupt it. Conclusion: The study highlights some of the challenges of addressing (anti)racism within PETE and argues that a focus on whiteness might offer a productive starting point. White teacher educators must critically examine their own role within these processes if they are to expect student teachers to engage seriously in doing the same

A comparison of two methods for estimating odds ratios: Results from the National Health Survey

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Are benefits and harms in mammography screening given equal attention in scientific articles? A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The CONSORT statement specifies the need for a balanced presentation of both benefits and harms of medical interventions in trial reports. However, invitations to screening and newspaper articles often emphasize benefits and downplay or omit harms, and it is known that scientific articles can be influenced by conflicts of interest. We wanted to determine if a similar imbalance occurs in scientific articles on mammography screening and if it is related to author affiliation.</p> <p>Methods</p> <p>We searched PubMed in April 2005 for articles on mammography screening that mentioned a benefit or a harm and that were published in 2004 in English. Data extraction was performed by three independent investigators, two unblinded and one blinded for article contents, and author names and affiliation, as appropriate. The extracted data were compared and discrepancies resolved by two investigators in a combined analysis. We defined three groups of authors: (1) authors in specialties unrelated to mammography screening, (2) authors in screening-affiliated specialties (radiology or breast cancer surgery) who were not working with screening, or authors funded by cancer charities, and (3) authors (at least one) working directly with mammography screening programmes. We used a data extraction sheet with 17 items described as important benefits and harms in the 2002 WHO/IARC-report on breast cancer screening.</p> <p>Results</p> <p>We identified 854 articles, and 143 were eligible for the study. Most were original research. Benefits were mentioned more often than harms (96% vs 62%, P < 0.001). Fifty-five (38%) articles mentioned only benefits, whereas seven (5%) mentioned only harms (P < 0.001). Overdiagnosis was mentioned in 35 articles (24%), but was more often downplayed or rejected in articles that had authors working with screening, (6/15; 40%) compared with authors affiliated by specialty or funding (1/6; 17%), or authors unrelated with screening (1/14; 7%) (P = 0.03). Benefits in terms of reduced breast cancer mortality were mentioned in 109 (76%) articles, and was more often provided as a relative risk reduction than an absolute risk reduction, where quantified (45 articles (31%) versus 6 articles (3%) (P < 0.001)).</p> <p>Conclusion</p> <p>Scientific articles tend to emphasize the major benefits of mammography screening over its major harms. This imbalance is related to the authors' affiliation.</p

Risk factors for overweight and obesity, and changes in body mass index of Chinese adults in Shanghai

<p>Abstract</p> <p>Background</p> <p>Over the past two decades, the prevalence of overweight or obesity has increased in China. The aims of this study were to firstly assess the baseline prevelences and the risk factors for overweight and obesity, and secondly to detect the changes of body mass index (BMI) over a follow-up period in Chinese adults in Shanghai.</p> <p>Methods</p> <p>The data set of a population-based longitudinal study was analyzed. Anthropometric and biochemical data were collected for 5364 subjects (aged 25–95 years) during a period of 1998–2001. Among those individuals, 3032 subjects were interviewed and reexamined at the second survey from 2003 to 2004. Then the standardized prevalences for overweight and obesity were calculated using baseline data; the possible contributing factors of overweight and obesity were detected using binary logistic regression analysis; and the changes of BMI were evaluated after an average of 3.6-year follow-up period.</p> <p>Results</p> <p>(1) According to the WHO standard and the Chinese standard, the sex- and age-standardized prevalences were 27.5% and 32.4% for overweight, and 3.7% and 9.1% for obesity, respectively. (2) The risks of overweight and obesity differed among different age groups. Family history of obesity increased the risk of overweight and obesity by about 1.2-fold for both genders. Current male smokers had a lower risk of overweight and obesity (OR = 0.76, <it>p </it>< 0.05) than nonsmokers. In contrast, current male drinkers had a higher risk of overweight and obesity (OR = 1.42, <it>p </it>< 0.05) than nondrinkers. Compared with low-educated women, medium- and high- educated women were at lower risk of overweight and obesity, and the corresponding ORs (95% CIs) were 0.64 (0.52–0.79) and 0.50(0.36–0.68), respectively. (3) The annual changes of BMI means ranged from an increase of 0.1 kg/m²to a decrease of 0.2 kg/m²(by genders and age groups). Meanwhile, the BMI increase was statistically significant in the 35–44 years age group, and the BMI decrease was significant above 65 years for both genders.</p> <p>Conclusion</p> <p>This study showed high prevalence of overweight and obesity in Shanghai metropolis populations. The risk factors of overweight and obesity were multifactorial and gender specific. After 3.6 years, BMI means changed slightly, BMI increased mainly in middle-aged individuals and decreased in old individuals.</p

A new Late Agenian (MN2a, Early Miocene) fossil assemblage from Wallenried (Molasse Basin, Canton Fribourg, Switzerland)

Excavations of two fossiliferous layers in the Wallenried sand- and marl pit produced a very diversified vertebrate fauna. New material allows the reassessment of the taxonomic position of the ruminant taxa Andegameryx andegaviensis and endemic Friburgomeryx wallenriedensis. An emended diagnosis for the second species is provided and additional material of large and small mammals, as well as ectothermic vertebrates, is described. The recorded Lagomorpha show interesting morphological deviations from other Central European material, and probably represent a unique transitional assemblage with a co-occurrence of Titanomys, Lagopsis and Prolagus. Rodentia and Eulipotyphla belong to typical and well-known species of the Agenian of the Swiss Molasse Basin. Abundant small mammal teeth have allowed us to pinpoint the biostratigraphic age of Wallenried to late MN2a. The biostratigraphic age conforms to data derived from the charophyte assemblages and confirms the oldest occurrence of venomous snake fangs. The palaeoenvironmental context is quite complex. Sedimentary structures and fauna (fishes, frogs, salamanders, ostracods) are characteristic for a humid, lacustrine environment within a flood plain system

The militarisation of English schools: Troops to Teaching and the implications for Initial Teacher Education and race equality

This article considers the implications of the Troops to Teaching (TtT) programme, to be introduced in England in autumn 2013, for Initial Teacher Education (ITE) and race equality. TtT will fast-track ex-armed service members to teach in schools, without necessarily the requirement of a university degree. Employing theories of white supremacy, and Althusser’s (1971) concept of Ideological and Repressive State Apparatus, I argue that this initiative both stems from, and contributes to, a system of social privilege and oppression in education. Despite appearing to be aimed at all young people, the planned TtT initiative is actually aimed at poor and racially subordinated youth. This is likely to further entrench polarisation in a system which already provides two tier educational provision: TtT will be a programme for the inner-city disadvantaged, whilst wealthier, whiter schools will mostly continue to get highly qualified teachers. Moreover, TtT contributes to a wider devaluing of current ITE; ITE itself is rendered virtually irrelevant, as it seems TtT teachers will not be subject specialists, rather will be expected to provide military-style discipline, the skills for which they will be expected to bring with them. More sinister, I argue that TtT is part of the wider militarisation of education. This military-industrial-education complex seeks to contain and police young people who are marginalised along lines of race and class, and contributes to a wider move to increase ideological support for foreign wars - both aims ultimately in the service of neoliberal objectives which will feed social inequalities