Exchange reactions of poly(arylene ether ketone) dithioketals with aliphatic diols: formation and deprotection of poly(arylene ether ketal)s

The dithioketal derivatives of industrially important, semi-crystalline poly(arylene ether ketone)s undergo facile exchange with aliphatic diols in the presence of N-bromo-succinimide to give a range of novel poly(arylene ether ketal)s. These are amorphous and readily soluble in a wide range of organic solvents. Although generally stable under ambient conditions, they undergo rapid and quantitative hydrolysis in the presence of acids to regenerate the original polyketones. The poly(ether ketal)s reported here are not accessible from ketal-type monomers, nor can they be obtained by direct reaction of poly(ether ketone)s with aliphatic diols. The starting polyketones are essentially unchanged after sequential dithioketalization, dithioketal-ketal exchange, ketal hydrolysis, and re-dithioketalization. Poly(arylene ether ketal)s provide a new approach to the processing of poly(arylene ether ketone)s into carbon fiber composite materials

The Asymmetric Rotor. IX. The Heavy Water Bands at 2787 cm^–1 and 5373 cm^–1

The combination band (110) of the two stretching fundamentals of D2O is reported and analyzed to yield nu0=5373.2 cm^–1 and the excited state moments of inertia 1.910, 3.931, and 5.929×10^–40 g cm^2. The same method of analysis applied to the unsymmetrical fundamental band (100) envelope gives nu0=2787.5 cm^–1 and the excited state moments 1.881, 3.876, and 5.843×10^–40 g cm^2

Management of multi-method engineering design research: a case study

There is a need for a research management methodology that will utilise research methods on an individual basis and when combined in a multi-method approach. An agreed methodology would enable rapid progress in achieving agreement on the main issues within engineering design research. Researchers at the University of Glasgow have developed a conceptual management methodology, testing it on three engineering design research projects. This paper describes the methodology and presents results indicating its ability to enable rigorous triangulation of research results obtained via different methods and across different research projects forming the basis of an effective management tool

An absorption tube for the investigation of gases in the photographic infrared

An absorption cell of novel design is described, which combines the advantages of long path and relatively small volume

The stochastic dynamics of nanoscale mechanical oscillators immersed in a viscous fluid

The stochastic response of nanoscale oscillators of arbitrary geometry immersed in a viscous fluid is studied. Using the fluctuation-dissipation theorem it is shown that deterministic calculations of the governing fluid and solid equations can be used in a straightforward manner to directly calculate the stochastic response that would be measured in experiment. We use this approach to investigate the fluid coupled motion of single and multiple cantilevers with experimentally motivated geometries.Comment: 5 pages, 5 figure

Mapping a landscape of learning design: Identifying key trends in current practice at the Open University

The object of this paper is to present some early analysis of interview and focus group data about how existing teacher educators at The Open University (UK) approach, understand, and deploy learning design and the additional support and tools they would find helpful. This represents a component of a broader institutional project that seeks to develop a learning design tool for the support and promotion of learning design and to better define the current landscape of learning design across the university by charting existing experience and methodology. This study is interested in design as both an individual and collective process; thereby reflecting the need to move forward the definition of the learning design challenges faced by both individuals and organisations. Such work holds interest for all developers and users of learning design tools, whatever the design interface used. Twelve semi-structured interviews and four focus groups/workshops were conducted with University staff. The views expressed in the interviews reveal 'learning design' as a term with multiple, complex and sometimes competing roles and meanings. This paper will examine evidence for these conceptions and operations through a discussion of some issues emerging from the interviews

Cloudworks: social networking for learning design

Why do some social networking services work and others fail? Can we apply the best of Web 2.0 principles to an educational context? More specifically can we use this as a means of shifting teaching practice to a culture of sharing learning ideas and designs? Can we harness the potential of technologies to create more engaging learning experiences for students? These are the key questions this paper addresses. We describe how we are using the concept of 'object-orientated social networking' to underpin the creation of a social networking tool, Cloudworks, for sharing learning ideas and designs

Traveling waves in rotating Rayleigh-Bénard convection: Analysis of modes and mean flow

Numerical simulations of the Boussinesq equations with rotation for realistic no-slip boundary conditions and a finite annular domain are presented. These simulations reproduce traveling waves observed experimentally. Traveling waves are studied near threshhold by using the complex Ginzburg-Landau equation (CGLE): a mode analysis enables the CGLE coefficients to be determined. The CGLE coefficients are compared with previous experimental and theoretical results. Mean flows are also computed and found to be more significant as the Prandtl number decreases (from sigma=6.4 to sigma=1). In addition, the mean flow around the outer radius of the annulus appears to be correlated with the mean flow around the inner radius

Extensive chaos in Rayleigh-Bénard convection

Using large-scale numerical calculations we explore spatiotemporal chaos in Rayleigh-Bénard convection for experimentally relevant conditions. We calculate the spectrum of Lyapunov exponents and the Lyapunov dimension describing the chaotic dynamics of the convective fluid layer at constant thermal driving over a range of finite system sizes. Our results reveal that the dynamics of fluid convection is truly chaotic for experimental conditions as illustrated by a positive leading-order Lyapunov exponent. We also find the chaos to be extensive over the range of finite-sized systems investigated as indicated by a linear scaling between the Lyapunov dimension of the chaotic attractor and the system size