Application of high-speed motion analysis to measure shock in cushioned drops

A high-speed motion analysis technique for measuring shocks in cushioned drops is developed and compared with the conventional accelerometer method. Actual drop-test results show significant differences between the measured peak decelerations using the two methods. The drop-test results are also compared with the published cushion-curve data and are again found to be in disagreement. The errors associated with each method are discussed and related back to the observed differences in measured acceleration.     

Preparation of Nano-ZrO2 powder via a microwave-assisted hydrothermal method

ZrO₂ nanocrystals were synthesised by a microwave-assisted hydrothermal method using zirconium oxychloride (ZrOCl₂·8H₂O), yttrium chloride (YCl₃·6H₂O), and liquor ammonia (NH₃·H₂O) as raw materials, triethanolamine (TEOA) as mineraliser, and polyethylene glycol (PEG) as dispersant. The obtained products were characterised with thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show that the concentration of ZrOCl₂·8H₂O had little effect on the material properties, whereas the PEG molecular weight, microwave hydrothermal time and temperature, and the concentration of TEOA greatly influenced the dispersibility of the nano-sized zirconia powders. XRD and FT-IR analyses indicated that the ZrO₂ nanocrystals synthesised by the microwave hydrothermal method had a tetragonal phase without any trace of monoclinic or cubic phases. The optimal parameters for preparing nano-zirconia powders with appreciable crystallinity and crystal forms included the use of PEG1000/PEG2000/PEG4000 dispersants, a microwave hydrothermal time of 30–50 min and a temperature of 200–240 °C, and a TEOA concentration of 0.3–0.5 M. Nano-ZrO₂ powder prepared via our optimised microwave hydrothermal method contained mostly tetrahedral, spherically shaped, highly homogeneous, and well-dispersed 20–30 nm particles.     

Image quality, the ideal observer, and human performance of radiologic decision tasks

The quality of medical images must be quantified with reference to specific diagnostic tasks. Image quality is limited by fundamental physics, engineering limitations, radiation safety concerns, and imaging time constraints (among other things). There is now a gold standard for assessing human visual decision performance: the ideal Bayesian observer. Unfortunately, there are no mathematical tools to use this gold standard for realistically complex tasks. As an alternative, one can use the optimum linear discriminator (Fisher-Hotelling) model as a silver standard while en route to clinical realism. The goal of scientists working in the area is to develop mathematical models of human observers that will help equipment designers to optimize design trade-offs for specific diagnostic tasks. The current strategy is to modify the Fisher-Hotelling model to include certain limitations of the human observer visual system. The model must be both robust enough and mathematically tractable enough to be used to predict performance for clinical classification and estimation tasks. Statistical models also must be developed that describe realistic signals (lesions and abnormalities) and the normal patient structure that is the background in which these signals must be detected or identified.     

Aedes albopictus: a potential problem in the United Kingdom

The United Kingdom is within the geographical area in which Aedes albopictus could survive. A large number of used car tyres are imported and a number of introduced cases of dengue fever occur annually. The health authorities should be aware of the possibility of dengue transmission.     

Intensity-intensity fluctuations of stochastic fields produced upon weak scattering

We derive expressions for the intensity-intensity correlations of a field produced on scattering of a random field governed by Gaussian statistics from a particle with a deterministic or a random refractive index distribution. Our results generalize the ones in [Opt. Lett. 35, 4000, 2010] to the case of an arbitrarily correlated incident field. We consider as specific examples the cases of a single plane wave and two partially correlated plane waves incident upon the scatterer.     

"Personality and risk for Alzheimer's disease in adults 72 years of age and older: A 6-year follow-up": Correction to Duberstein et al. (2010).

Reports an error in "Personality and risk for Alzheimer's disease in adults 72 years of age and older: A 6-year follow-up" by Paul R. Duberstein, Benjamin P. Chapman, Hilary A. Tindle, Kaycee M. Sink, Patricia Bamonti, John Robbins, Anthony F. Jerant and Peter Franks (Psychology and Aging, , , np). This article contains an error in the Discussion, under the Implications, Caveats, Future Directions heading. The third paragraph includes sentences that should have been removed, as they are a variation on similar text immediately following. The sentences that should have been removed are presented in the erratum. (The following abstract of the original article appeared in record 2010-22067-001.) We conducted secondary analyses to determine the relationship between longstanding personality traits and risk for Alzheimer's disease (AD) among 767 participants 72 years of age or older who were followed for more than 6 years. Personality was assessed with the NEO-FFI. We hypothesized that elevated Neuroticism, lower Openness, and lower Conscientiousness would be independently associated with risk of AD. Hypotheses were supported. The finding that AD risk is associated with elevated Neuroticism and lower Conscientiousness can be added to the accumulating literature documenting the pathogenic effects of these two traits. The link between lower Openness and AD risk is consistent with recent findings on cognitive activity and AD risk. Findings have implications for prevention research and for the conceptualization of the etiology of AD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Entrepreneur Makers: Digitally Crafted,Crowdfunded Pavilions

As part of a generation of architects graduating after the 2008 global financial crisis, Arthur Mamou-Mani and Toby Burgess developed an ethos of digital self-sufficiency. This is one that they have passed on to their students in Diploma Studio 10 at the University of Westminster, teaching them to self-build using digital fabrication techniques, but also to fund their work through crowdfunding, while promoting it on social media.     

Quantum dot transport in soil, plants, and insects

Environmental risk assessment of nanomaterials requires information not only on their toxicity to non-target organisms, but also on their potential exposure pathways. Here we report on the transport and fate of quantum dots (QDs) in the total environment: from soils, through their uptake into plants, to their passage through insects following ingestion. Our QDs are nanoparticles with an average particle size of 6.5 nm. Breakthrough curves obtained with CdTe/mercaptopropionic acid QDs applied to columns of top soil from a New Zealand organic apple orchard, a Hastings silt loam, showed there to be preferential flow through the soil's macropores. Yet the effluent recovery of QDs was just 60%, even after several pore volumes, indicating that about 40% of the influent QDs were filtered and retained by the soil column via some unknown exchange/adsorption/sequestration mechanism. Glycine-, mercaptosuccinic acid-, cysteine-, and amine-conjugated CdSe/ZnS QDs were visibly transported to a limited extent in the vasculature of ryegrass (Lolium perenne), onion (Allium cepa) and chrysanthemum (Chrysanthemum sp.) plants when cut stems were placed in aqueous QD solutions. However, they were not seen to be taken up at all by rooted whole plants of ryegrass, onion, or Arabidopsis thaliana placed in these solutions. Leafroller (Lepidoptera: Tortricidae) larvae fed with these QDs for two or four days, showed fluorescence along the entire gut, in their frass (larval feces), and, at a lower intensity, in their haemolymph. Fluorescent QDs were also observed and elevated cadmium levels detected inside the bodies of adult moths that had been fed QDs as larvae. These results suggest that exposure scenarios for QDs in the total environment could be quite complex and variable in each environmental domain.     

Fasciculography: robust prior-free real-time normalized volumetric neural tract parcellation

Fiber tracking in diffusion tensor magnetic resonance images (DTIs) reveals 3-D structural connectivity of the brain conveniently and thus is a viable tool for investigating neural differences. Unfortunately, local noise, image artifacts and numerical tracking errors during integration-based techniques are cumulative. Prematurely terminated fibers and under-sampled fiber bundles result in incomplete reconstruction of white matter fiber tracts and hence incorrect anatomical measurements. Quantitative cross-subject tract analysis, which is critical for abnormality detection, is complicated by inefficient and inaccurate tract reconstruction and normalization from fiber bundles. Because of the above problems, we propose a parcellation method that aims for lower sensitivity to initialization and local orientation error by directly segmenting full white matter tracts (Fasciculography), rather than reconstructing individual curves, from diffusion tensor fields. A fast, robust volumetric, and intrinsically normalized solution is achieved by noise-filtering using a generic parametrized tract model to prevent premature tract termination. At the same time, orientation information reduces the search space, significantly speeding up the tract parcellation process with less human intervention. Detailed comparisons against streamline tracking, shortest-path tracking, and nonrigid registration using synthetic and real DTIs confirmed the superior properties of Fasciculography. Since a normalized tract can be delineated interactively in a just few seconds using the proposed method, accurate high volume tract comparisons become feasible.     

Oxygen sorption and transport in amorphous poly(ethylene furanoate)

Oxygen transport in amorphous poly(ethylene furanoate) (PEF) was studied at various temperatures using complementary permeation and pressure-decay sorption techniques. A significant reduction in oxygen permeability of ∼11× was observed at 35 °C for PEF compared to poly(ethylene terephthalate) (PET), and is attributed primarily to reduction in chain segment mobility for PEF resulting from a hindrance of furan ring flipping. A custom-built high accuracy sorption system allowed determination of temperature-dependent so-called dual-mode parameters that have not been reported for oxygen in any polyester. Energetic parameters, i.e. the enthalpy of sorption and activation energies of diffusion and permeation, were measured for oxygen in PEF and discussed in the context of PET and related polyesters. The current work presents the first detailed study of penetrant transport in PEF, which demonstrates the impressive performance enhancements of PEF compared to PET.