Turbulence structure of open channel flows over permeable and impermeable beds : A comparative study

Peer reviewedPublisher PD

Bed-load effects on hydrodynamics of rough-bed open-channel flows

Peer reviewedPublisher PD

Efficient computational noise in GLSL

We present GLSL implementations of Perlin noise and Perlin simplex noise that run fast enough for practical consideration on current generation GPU hardware. The key benefits are that the functions are purely computational, i.e. they use neither textures nor lookup tables, and that they are implemented in GLSL version 1.20, which means they are compatible with all current GLSL-capable platforms, including OpenGL ES 2.0 and WebGL 1.0. Their performance is on par with previously presented GPU implementations of noise, they are very convenient to use, and they scale well with increasing parallelism in present and upcoming GPU architectures

Nitroarylurea-terminated supramolecular polymers that exhibit facile thermal repair and aqueous swelling-induced sealing of defects

Bi- and tri-armed polyethylene glycol units endcapped with nitroaryl urea units have been synthesised. These endcapped polymers are able to self-assemble via complementary supramolecular interactions, specifically urea-urea and nitro-urea hydrogen bonding, to afford materials with dramatically increased mechanical and thermal properties when compared to those of the uncapped polyethylene glycol precursors. Thin films of the capped polymeric systems are able to self-repair following defect creation. Control over the mechanical and thermal characteristics (in terms of bulk viscosity) of the self-assembled networks was achieved by varying the proportion of tri-armed to bi-armed self-assembly units included in the polymer. These systems demonstrate water absorption and swelling capabilities that are also controllable by varying the ratio of the two types of unit. These physical properties have been optimised to realise a secondary pathway to puncture-repair as a result of swelling on water contact

Does the book have a future?

Advances in technology have produced a range of devices on which a book can be read, from an e‐book reader to a tablet or phone. E‐books have the advantages that a reader can take a sizeable selection when traveling, read backlit text, and enlarge the type size to suit. The book exists in both printed and digital form, as p‐book and e‐book. Digital technology has also revolutionized the production of printed books. Digital printing, as opposed to traditional offset printing, enables genuine print on demand as well as short runs. This facility has less relevance to the world of mass‐market paperbacks, where large print runs mean that the benefits of offset printing still apply, but it is of great interest to most publishers and those who want to self‐publish. In fact, more books are published than ever before, and there has been a boom in self‐publishing

What do older people do when sitting and why? Implications for decreasing sedentary behaviour

Background and Objectives: Sitting less can reduce older adults’ risk of ill health and disability. Effective sedentary behavior interventions require greater understanding of what older adults do when sitting (and not sitting), and why. This study compares the types, context, and role of sitting activities in the daily lives of older men and women who sit more or less than average. Research Design and Methods: Semistructured interviews with 44 older men and women of different ages, socioeconomic status, and objectively measured sedentary behavior were analyzed using social practice theory to explore the multifactorial, inter-relational influences on their sedentary behavior. Thematic frameworks facilitated between-group comparisons. Results: Older adults described many different leisure time, household, transport, and occupational sitting and non-sitting activities. Leisure-time sitting in the home (e.g., watching TV) was most common, but many non-sitting activities, including “pottering” doing household chores, also took place at home. Other people and access to leisure facilities were associated with lower sedentary behavior. The distinction between being busy/not busy was more important to most participants than sitting/not sitting, and informed their judgments about high-value “purposeful” (social, cognitively active, restorative) sitting and low-value “passive” sitting. Declining physical function contributed to temporal sitting patterns that did not vary much from day-to-day. Discussion and Implications: Sitting is associated with cognitive, social, and/or restorative benefits, embedded within older adults’ daily routines, and therefore difficult to change. Useful strategies include supporting older adults to engage with other people and local facilities outside the home, and break up periods of passive sitting at home

Self-control exertion and glucose supplementation prior to endurance performance

Objectives: Completion of a task requiring self-control may negatively impact on subsequent self-regulatory efforts. This study explored a) whether this effect occurs during a well-practiced endurance task, b) the potential for glucose supplementation to moderate this effect, and c) whether this effect differed over time. Method: Fourteen trained cyclists completed four simulated 16 km time trials on an electromagnetically braked cycle ergometer. Prior to each time trial, participants completed a congruent Stroop task or an incongruent Stroop task that required self-control. They also received either a glucose-based drink or placebo. Participants’ performance time and heart rate were recorded throughout the time trials. Results: Multilevel growth curve analysis revealed a significant three-way interaction between self-control, glucose, and time (b = -0.91; p = 0.02). When participants did not exert self-control (congruent Stroop) or consume glucose (placebo drink) they were slowest during the early stages of the time trial but quickest over the full distance. No differences were found in heart rate across the four conditions. Conclusions: Findings suggest that pacing may explain why self-control exertion interferes with endurance performance. Moreover, the debate revolving around depletion of self-control must consider that any observed effects may be dependent on the timing of performance inspection