Effect of load introduction on graphite epoxy compression specimens

Compression testing of modern composite materials is affected by the manner in which the compressive load is introduced. Two such effects are investigated: (1) the constrained edge effect which prevents transverse expansion and is common to all compression testing in which the specimen is gripped in the fixture; and (2) nonuniform gripping which induces bending into the specimen. An analytical model capable of quantifying these foregoing effects was developed which is based upon the principle of minimum complementary energy. For pure compression, the stresses are approximated by Fourier series. For pure bending, the stresses are approximated by Legendre polynomials

Sculplexity: Sculptures of Complexity using 3D printing

We show how to convert models of complex systems such as 2D cellular automata into a 3D printed object. Our method takes into account the limitations inherent to 3D printing processes and materials. Our approach automates the greater part of this task, bypassing the use of CAD software and the need for manual design. As a proof of concept, a physical object representing a modified forest fire model was successfully printed. Automated conversion methods similar to the ones developed here can be used to create objects for research, for demonstration and teaching, for outreach, or simply for aesthetic pleasure. As our outputs can be touched, they may be particularly useful for those with visual disabilities.Comment: Free access to article on European Physics Letter

Magnetic properties of antiferromagnetically coupled CoFeB/Ru/CoFeB

This work reports on the thermal stability of two amorphous CoFeB layers coupled antiferromagnetically via a thin Ru interlayer. The saturation field of the artificial ferrimagnet which is determined by the coupling, J, is almost independent on the annealing temperature up to more than 300 degree C. An annealing at more than 325 degree C significantly increases the coercivity, Hc, indicating the onset of crystallization.Comment: 4 pages, 3 figure

Strong Magnetization Measured in the Cool Cores of Galaxy Clusters

Tangential discontinuities, seen as X-ray edges known as cold fronts (CFs), are ubiquitous in cool-core galaxy clusters. We analyze all 17 deprojected CF thermal profiles found in the literature, including three new CFs we tentatively identify (in clusters A2204 and 2A0335). We discover small but significant thermal pressure drops below all nonmerger CFs, and argue that they arise from strong magnetic fields below and parallel to the discontinuity, carrying 10%-20% of the pressure. Such magnetization can stabilize the CFs, and explain the CF-radio minihalo connection.Comment: PRL accepted, additional control tests adde

Girls in the UK have similar reasons to boys for intending to study mathematics post-16 thanks to the support and encouragement they receive

This paper focuses on the aspirations of 13- and 15-year-olds to continue with mathematics after the age of 16 and the association with perceptions of their mathematics education during the academic year 2008/9. A quantitative analysis was undertaken on the views of 12,176 UK students, obtained through surveys, with qualitative case studies on two of these students lending support to the quantitative findings. This paper also places a focus on a sub-set of 1,476 London students. The analysis indicates that girls and boys with high mathematics aspirations had similar responses towards their mathematics teachers and lessons, and had comparable extrinsic mathematics motivation. However, girls, regardless of mathematics aspirations, were less likely than boys to be encouraged by their families and others within their social circles to study mathematics post-16. Many of the London findings are similar to those we found across the UK, although girls within London schools with high mathematics aspirations perceived their mathematics education to be more equitable. Low aspiring girls across the UK and in London still reported less support and encouragement, and described their mathematics education less favourably than did boys

“I Fall Asleep in Class … But Physics Is Fascinating”: The Use of Large-Scale Longitudinal Data to Explore the Educational Experiences of Aspiring Girls in Mathematics and Physics

This article explores how students' aspirations to study mathematics or physics in post-16 education are associated with their perceptions of their education, their motivations, and the support they feel they received. The analysis is based on the responses of around 10,000 students in England in Year 8 (age 12–13) and then in Year 10 (age 14–15). The students were first surveyed during 2008–2009 and then followed up in 2010–2011. t-tests revealed a decline in their perceptions of their mathematics and physics education. Factor analyses indicated subject-specific constructs that were associated with gender aspiration groups (i.e., high-aspiring girls, high-aspiring boys, low-aspiring girls, low-aspiring boys). High-aspiring girls were more likely than low-aspiring boys to be positive about mathematics/physics education, motivation in these subjects, and support received. However, high-aspiring girls were less likely than high-aspiring boys to be encouraged by their teachers and families to continue with these subjects post-16 and had lower self-concepts, intrinsic valuations, and perceptions of lessons. Low-aspiring girls reported the least favorable views of their mathematics/physics education of all four gender aspiration groups. Findings were generally similar for mathematics and physics, although students overall responded more favorably to mathematics than to physics. The quantitative findings are illustrated with extracts from longitudinal interviews (ages 15, 16, and 17) of two high-aspiring girls

The Millennium Development Goals Agenda: Constraints of Culture, Economy, and Empowerment in Influencing the Social Mobility of Pakistani Girls on Mathematics and Science Related Higher Education Courses in Universities in Pakistan

The third of the eight Millennium Development Goals is to promote gender equality and empower women. This article discusses the factors that are associated with 31 female higher education students’ choices and aspirations to pursue education and careers in mathematics and science-related fields. The analysis is based on semistructured interviews. Patriarchal values in society impacted females’ own perceptions of their abilities and aspirations. Although extrinsic social gain motivation underpinned females’ choices, they had little awareness of the economic benefits of mathematics and science qualifications. Teaching styles were associated with females leaving the mathematics and science pipeline. / Le troisième des huit Objectifs de développement du millénium est de promouvoir l’égalité des sexes et de donner aux femmes le pouvoir de s’assumer. Cet article traite des facteurs liés aux choix et aux aspirations de 31 étudiantes universitaires ayant élu d’entreprendre une carrière en mathématiques ou dans un autre domaine scientifique. Notre analyse se fonde sur des entrevues semi-structurées. Les valeurs patriarcales de la société ont influencé la perception que les femmes elles-mêmes ont de leurs habiletés et aspirations. Bien que les motivations extrinsèques de gain social sous-tendent les choix des femmes, elles sont peu conscientes des avantages économiques liés aux compétences et aux diplômes de mathématiques ou de sciences. Il ressort que certains styles d’enseignement sont associés à l’abandon des mathématiques et des sciences de la part des femmes

Should we embed careers education in STEM lessons?

Published by Informa UK Limited, trading as Taylor & Francis Group.Schools have a particular responsibility to introduce young people to the range of possible options for them after they leave education as few families can provide this. However, in the United Kingdom, careers education is currently not strong in most schools for a number of reasons but principally due to its low status and shifts in government policy and funding. As a result, too many young people make subject choices for post-16 study that they subsequently regret. In particular, fewer young people in the United Kingdom choose post-16 STEM subjects than might do. Yet, STEM (science, technology, engineering and mathematics) graduates are especially valued by employers. We draw on the findings of two research projects, ASPIRES and UPMAP, and argue that one way forward may be to embed careers education in STEM lessons. This can be done in ways that are respectful of and helpful to students. We recommend that an England- or UK-based project to investigate the consequences of embedding careers education in STEM lessons be undertaken