Large amplitude free vibration of a flexible panel coupled with a leaking cavity

This paper addresses the effect of leakage on the natural frequencies of a large amplitude vibrating panel backed by a cavity, which has not been considered in many other related studies. The structural-acoustic governing equations are employed to study this nonlinear problem. An elliptical integral method, which was recently developed for the nonlinear panel cavity problem, is introduced here to solve for the structural-acoustics responses. The present results agree reasonably well with those obtained from the classical harmonic balance method. Modal convergences of the nonlinear solutions are performed to verify the proposed method. The effects of vibration amplitude and leakage size are studied and discussed. It is found that (1) the edge leakages in a panel cavity system significantly affect the natural frequency properties, and (2) the edge leakages induce a low frequency acoustic resonance.     

Exploring Relationships Among Belief in Genetic Determinism,Genetics Knowledge,and Social Factors

Genetic determinism can be described as the attribution of the formation of traits to genes, where genes are ascribed more causal power than what scientific consensus suggests. Belief in genetic determinism is an educational problem because it contradicts scientific knowledge, and is a societal problem because it has the potential to foster intolerant attitudes such as racism and prejudice against sexual orientation. In this article, we begin by investigating the very nature of belief in genetic determinism. Then, we investigate whether knowledge of genetics and genomics is associated with beliefs in genetic determinism. Finally, we explore the extent to which social factors such as gender, education, and religiosity are associated with genetic determinism. Methodologically, we gathered and analyzed data on beliefs in genetic determinism, knowledge of genetics and genomics, and social variables using the “Public Understanding and Attitudes towards Genetics and Genomics” (PUGGS) instrument. Our analyses of PUGGS responses from a sample of Brazilian university freshmen undergraduates indicated that (1) belief in genetic determinism was best characterized as a construct built up by two dimensions or belief systems: beliefs concerning social traits and beliefs concerning biological traits; (2) levels of belief in genetic determination of social traits were low, which contradicts prior work; (3) associations between knowledge of genetics and genomics and levels of belief in genetic determinism were low; and (4) social factors such as age and religiosity had stronger associations with beliefs in genetic determinism than knowledge. Although our study design precludes causal inferences, our results raise questions about whether enhancing genetic literacy will decrease or prevent beliefs in genetic determinism.     

Examining Intermediate Omitted Levels in Hierarchical Designs via Latent Variable Modeling

This article outlines an interval estimation procedure that can be used in a 3-level setting to evaluate the proportion of outcome variance attributable to the second level of clustering. The method is useful for examining the necessity of including a possibly omitted intermediate level of nesting in analyses of data from a multilevel study, and represents an informative addendum to current statistical tests of second-level variance. The approach is developed within the framework of latent variable modeling and can be used as an aid in the process of choosing between 2-level and 3-level models in a hierarchical design. The discussed procedure is illustrated with an empirical example.     

‘Research as dialogue’ and cross-cultural consultations: confronting relations of power

In this paper, we discuss methodological issues that emerged as we worked through a small empirical research project, ‘Engaging Aboriginal students in education through community empowerment’. Recent national policy statements (see, for example, MCEETYA 2000, NBEET 1995) argue the importance of education/research that keeps the locus of control within the Aboriginal community as a means to further the goal of self-determination and improve educational outcomes. In keeping with these recommendations, our project aimed to challenge assimilationist frameworks and sought to ‘empower’ members of the local Aboriginal community through participation in the project.     

Young Children’s Curiosity About Physical Differences Associated with Race: Shared Reading to Encourage Conversation

Many have called for re-examination of the “colorblind” philosophy to which some early educators have, tacitly or explicitly, adhered (e.g. Boutte et al. 2011; Derman-Sparks and Edwards 2010; Husband 2012). It has been argued that, while colorblind approaches may appear to be politically neutral, they actually exacerbate racial oppression. In this article, we advocate for a direct and active approach to raising conversations about race with younger preschool children. Based on the developmental nature of young children’s concepts of self and of other, our focus is on initiating discussions about concrete and observable physical aspects of human diversity associated with race. Young children notice and are curious about differences in skin color, hair texture, and facial features. Because these differences are salient, are accessible, and are of interest to young children they can serve as an effective starting point. We suggest shared reading of high quality illustrated children’s books, incorporating the principles of dialogic reading, as a potent springboard for discussions about race with very young children. Our purpose is to equip children, very early in their schooling, with a color-filled appreciation for and comfort with physical diversity of appearance. On that foundation, children may better proceed on the course of developing anti-racist attitudes.     

Fostering scientific understanding and epistemic beliefs through judgments of promisingness

The evaluation of promisingness is central to knowledge building and knowledge creation but remains largely unexplored. As part of a design-based research program to support promisingness judgments, the present study implemented an intervention in a sixth grade science class, with the goal of exploring the potential of promisingness judgments to foster scientific understanding and epistemic beliefs. Aided by a Promising Ideas Tool and pedagogical supports designed for this intervention, students explored the concept of promisingness, judged the promisingness of their community ideas, and engaged in iterative cycles of idea refinement. Results indicated that students were capable of improving their understanding of promisingness and making promisingness judgments deemed sensible by domain experts. The conceptual understanding and epistemic beliefs displayed by students improved over the course of the intervention, and such improvement happened in tandem with students’ understanding of promisingness. The implications of this exploratory study and future research are discussed.     

Motion characteristics of novel floating foundation for offshore wind turbine

A novel floating foundation to support the NREL offshore 5 MW wind turbine was designed conceptually by combining the characteristics of barge and Spar. The main focus was structural design and hydrodynamic modelling. Based on this novel floating foundation, the hydrodynamic performance was investigated in the frequency domain and time domain by using the wave analysis software HydroD and DeepC from Det Norske Veritas. The frequency domain analysis was conducted to investigate the effects of the incident wave angle and water depth. The time-domain analysis was carried out to evaluate the response of the floating foundation under a selected operational condition. The hydrodynamic performances of this floating foundation with respect to time series and response spectra were also investigated in this study.