Lumped parameter model for resonant frequency estimation of a thermoacoustic engine with gas-liquid coupling oscillation

Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude of a thermoacoustic engine. If a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators, the frequency matching between the thermoacoustic engine and the refrigerator plays an important role. Based on an acoustic-electric analogy, a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid coupling oscillation. Furthermore, a simplified lumped parameter model is also developed to reduce the computation complexity. The resonant frequency dependence on the mean pressure, the gas space volume, and the water column length is computed and analyzed. The impact of different working gases on the resonant frequency is also discussed. The effectiveness of the models is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation system. An increase in the mean working pressure can lead to a rise in the resonant frequency, and a lower resonant frequency can be achieved by elongating the liquid column. In comparison with nitrogen and argon, carbon dioxide can realize a lower frequency due to a smaller specific heat ratio.     

Geometry of screw compressor rotors and their tools

This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools. It describes the details of lobe shape specification, and focuses on a new lobe profile, which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed. A well proven mathematical model was used to determine the optimum profile, compressor housing size, and compressor ports to achieve the superior compressors.     

Disgust,Need for Affect,and Responses to Microbiome Research

Contributing to the literature on affective processing and attitude formation, this study investigates the effects of a discrete emotion (disgust) and an emotional disposition (need for affect [NFA]) on support for regulation in the context of microbiome research. Data from a web-based experiment (N = 1,005) showed that experienced disgust mediated the effect of disgust-eliciting information on support for regulation. This mediated relationship was moderated by NFA. More specifically, NFA moderated the path between experienced disgust and regulatory attitudes but not that between message exposure and experienced disgust. The two dimensions of NFA played different moderating roles: Emotional approach amplified the relationship between disgust and the attitudinal outcome, whereas emotional avoidance attenuated it. The study furthers understanding about how NFA influences emotional processing and contributes to research on disgust as a relatively understudied discrete emotion.     

The Colorado Learning Attitudes about Science Survey (CLASS) for use in Biology

This paper describes a newly adapted instrument for measuring novice-to-expert-like perceptions about biology: the Colorado Learning Attitudes about Science Survey for Biology (CLASS-Bio). Consisting of 31 Likert-scale statements, CLASS-Bio probes a range of perceptions that vary between experts and novices, including enjoyment of the discipline, propensity to make connections to the real world, recognition of conceptual connections underlying knowledge, and problem-solving strategies. CLASS-Bio has been tested for response validity with both undergraduate students and experts (biology PhDs), allowing student responses to be directly compared with a consensus expert response. Use of CLASS-Bio to date suggests that introductory biology courses have the same challenges as introductory physics and chemistry courses: namely, students shift toward more novice-like perceptions following instruction. However, students in upper-division biology courses do not show the same novice-like shifts. CLASS-Bio can also be paired with other assessments to: 1) examine how student perceptions impact learning and conceptual understanding of biology, and 2) assess and evaluate how pedagogical techniques help students develop both expertise in problem solving and an expert-like appreciation of the nature of biology.     

Enhancing the Executive Functions of 3‐Year‐Olds in the Dimensional Change Card Sort Task

Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3‐year‐olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that prior experience with the postswitch dimension can enhance 3‐year‐olds' performance in the DCCS. In Experiment 1A, a matching game was used to preexpose 3‐year‐olds (n = 36) to color. This facilitated switching from sorting by shape to color. In 3 , 3‐year‐olds (n = 18) were preexposed to shape. This did not facilitate switching from sorting by color to shape. The model was used to explain this asymmetry.     

Pre-service teacher training in health and well-being in England: the state of the nation

This paper presents findings from a survey of pre-service teacher training institutions in England with regard to the provision of health and well-being education. It examines factors affecting the inclusion of health and well-being, and explores educational implications in light of the changing landscape of pre-service teacher education in England. Provision of health and well-being education is noticeably variable across institutions, and many course leaders are unclear about the coverage in their partner schools. Course leaders regard health and well-being as an important part of the curriculum, but the focus is usually on generic health-related themes such as child protection and behaviour management, which address Government priorities, rather than on specific topics such as education about diet, drugs, alcohol, smoking, sex and relationships and physical activity. The paper argues that these aspects should be addressed for pre-service teachers to have an increased sense of self-efficacy and become capable health promoters.     

Parental perspectives and challenges in inclusive education in Singapore

Relatively little work has focused on inclusive education in Singapore. This study examines the experiences and perceptions of parents whose children with disabilities are attending mainstream secondary schools in Singapore. Data was drawn from interviews with 13 parents of children with mild disabilities. Our findings reveal that parental perspective on inclusive education in Singapore is not only about classroom support but also reflects a deeper concern about whether their children with disabilities will emerge from school as contributing individuals in society. While parents strive to effectively include their children with disabilities in mainstream classrooms, there were dichotomies in their (1) understanding of disabilities, (2) expectations of school support, and (3) expectations for their child with disabilities. Given that academic and social prowess is a critical prerequisite to have a shot at entering the meritocratic Singapore society, the tension parents experience is to gauge a reasonable amount of pressure to exert on their children, the school and themselves as they assert their children's educational entitlements within an imperfect but evolving state of inclusion.     

Challenges in embedding numeracy throughout the curriculum in three Queensland secondary schools

The Australian Curriculum identified seven General Capabilities, including numeracy, to be embedded in all learning areas. However, it has been left to individual schools to manage this. Whilst there is a growing body of literature about pedagogies that embed numeracy in various learning areas, there are few studies from the management perspective. A social constructivist perspective and a multiple case study approach were used to explore the actions of school managers and mathematics teachers in three Queensland secondary schools, in order to investigate how they meet the Australian Curriculum requirement to embed numeracy throughout the curriculum. The study found a lack of coordinated cross-curricular approaches to numeracy in any of the schools studied. It illustrates the difficulties that arise when teachers do not share the Australian Curriculum cross-curricular vision of numeracy. Schools and curriculum authorities have not acknowledged the challenges for teachers in implementing cross-curricular numeracy, which include: limited understanding of numeracy; a lack of commitment; and inadequate skills. Successful embedding of numeracy in all learning areas requires: the commitment and support of school leaders, a review of school curriculum documents and pedagogical practices, professional development of teachers, and adequate funding to support these activities.     

The impact of a natural disaster: under- and postgraduate nursing education following the Canterbury,New Zealand,earthquake experiences

While natural disasters have been reported internationally in relation to the injury burden, role of rescuers and responders, there is little known about the impact on education in adult professional populations. A 7.1 magnitude earthquake affected the Canterbury region of New Zealand on 4 September 2010 followed by more than 13,000 aftershocks in the three years to September 2013. As part of a larger study, a mixed method survey was used to explore factors impacting nurses engaged in education through polytechnic and university courses. This paper presents factors that were self-identified by students as supporting their ability to continue with education. Participants were recruited from three nursing settings: undergraduate nursing students, Registered Nurses (RNs) engaged in post-registration education and RNs engaged in postgraduate courses. A total of 290 participants took part in the study. A number of factors identified by participants could be addressed in pre-disaster course planning and curriculum design; through education and support of both students and staff; and the active promotion of personal, professional and institutional resilience.