Development of a heterogeneous laminating resin system

The factors which effect the impact resistance of laminating resin systems and yet retain equivalent performance with the conventional 450 K curing epoxy matrix systems in other areas were studied. Formulation work was conducted on two systems, an all-epoxy and an epoxy/bismaleimide, to gain fundamental information on the effect formulation changes have upon neat resin and composite properties. The all-epoxy work involved formulations with various amounts and combinations of eight different epoxy resins, four different hardeners, fifteen different toughening agents, a filler, and a catalyst. The epoxy/bismaleimide effort improved formulations with various amounts and combinations of nine different resins, four different hardeners, eight different toughening agents, four different catalysts, and a filler. When a formulation appeared to offer the proper combination of properties required for a laminating resin Celion 3K-70P fabric was prepregged. Initial screening tests on composites primarily involved Gardner type impact and measurement of short beam shear strengths under dry and hot/wet conditions

Increased sclerostin associated with stress fracture of the third metacarpal bone in the Thoroughbred Racehorse

Abstract Objectives: The exact aetiopathogenesis of microdamage induced long bone fractures remains unknown. These fractures are likely the result of inadequate bone remodeling in response to damage. This study aims to identifiesy an association of osteocyte apoptosis, the presence of osteocytic osteolysis and any alterations in sclerostin expression with fracture of the third metacarpal bone of (Mc-III) thoroughbred (TB) racehorses. Methods: 30 Mc-III bones were obtained; 10 from bones fractured during racing, 10 from the contralateral limb and 10 from control horses. Each Mc- III bone was divided into fracture site, condyle, condylar groove and sagittal ridge. Microcracks and diffuse microdamage were quantified. Apoptotic osteocytes were measured using TUNEL staining. Cathepsin K, matrix metalloproteinase -13 (MMP-13), HtrA1 and sclerostin expression was analysed. of apoptotic cells between contralateral limb and unraced control, however, there were significantly less apoptotic cells in fractured samples (p<0.02). Immunohistochemistry showed that in the deep zones of the fractured samples sclerostin expression was significantly higher (p<0.03) of the total number of osteocytes. No increase in cathepsin K, MMP-13 or HtrA1 was present

Echoes of ECOs: gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale

Gravitational waves from binary coalescences provide one of the cleanest signatures of the nature of compact objects. It has been recently argued that the post-merger ringdown waveform of exotic ultracompact objects is initially identical to that of a black-hole, and that putative corrections at the horizon scale will appear as secondary pulses after the main burst of radiation. Here we extend this analysis in three important directions: (i) we show that this result applies to a large class of exotic compact objects with a photon sphere for generic orbits in the test-particle limit; (ii) we investigate the late-time ringdown in more detail, showing that it is universally characterized by a modulated and distorted train of "echoes" of the modes of vibration associated with the photon sphere; (iii) we study for the first time equal-mass, head-on collisions of two ultracompact boson stars and compare their gravitational-wave signal to that produced by a pair of black-holes. If the initial objects are compact enough as to mimic a binary black-hole collision up to the merger, the final object exceeds the maximum mass for boson stars and collapses to a black-hole. This suggests that - in some configurations - the coalescence of compact boson stars might be almost indistinguishable from that of black-holes. On the other hand, generic configurations display peculiar signatures that can be searched for in gravitational-wave data as smoking guns of exotic compact objects.Comment: 13 pages, RevTex4. v2: typo in equation 7 corrected, references added, to appear in PR

Dementia ambient care: ethical issues arising from the use of a home-based multi-sensor support system

Background: With the worldwide increase in dementia prevalence acceptable cost-effective home-based solutions are needed to support people with dementia (PwD) living in the community and to delay institutionalisation. Ambient assistive technologies represent a way of enabling independence and facilitating “ageing in place”, by supporting the health, lifestyle, and safety of PwD in an unobtrusive manner. However, ethical issues associated with their use remain under-reported. Methods: Dem@Care is an FP7 project that uses ambient and wearable sensors to support physical activity, sleep, activities of daily living, social interaction, and mood in PwD. It uses a multiple case study design with purposive sampling of people with early stage dementia. An individualised sensor “toolbox” and intervention strategy is developed for participants based on a clinical assessment of their needs. Sensor data is aggregated over time to identify changes in patterns of behaviour that could signify improvement, stasis, or deterioration of function. Results: Our first two case studies raised important ethical issues associated with sensor use. Difficulties using the technologies resulted in heightened anxiety for the PwD and their carer. Sensor ‘privacy’ buttons were often forgotten resulting in image capture that might not have been intended and was potentially embarrassing to the PwD, and ambient video recording could not be deployed given the lack of an acceptable solution to obtaining third party consent. Conclusions: Although potentially beneficial to PwD, the ethical issues associated with the use of ambient assistive technologies require further discussion given the vulnerability of this population

Predicting return to work from health related welfare following low intensity cognitive behaviour therapy

The aim of this study was to identify predictors of return to work in the short and long term following condition management cognitive-behavioural therapy (CM-CBT). All participants (N = 3794) were disability welfare claimants, unemployed due to the presence of a physical or mental health condition. CM-CBT consisted of a seven session group cognitive-behavioural psychoeducational programme, with participants followed-up at 3 and 12-30 months. The primary employment outcome measure was a categorical measure of either returned to work, made progress towards work or remained on welfare. Results index an incremental progress and return to work rate, increasing from 34.41 % at short-term follow-up to 53.07 % at long-term follow-up. Clinically, 17.40 % were classed as recovered following CM-CBT. Reliable psychological change during CM-CBT predicted successful return to work and remaining on welfare was associated with psychological regression over time. The results are discussed in terms of identified methodological weaknesses and the potential of CBT in enabling return to work for the health related unemployed

Dementia ambient care: multi-sensor support to enable independent home-based living for people with dementia

The quality of life of the person with dementia is often impacted by the loss of autonomy and independence that can arise during dementia progression. Ambient assistive technologies represent a way of enabling independence and facilitating “ageing in place”, by supporting the health, lifestyle, and safety of the person with dementia in an unobtrusive manner. Dem@Care is a European FP7 funded project, which is using ambient and wearable sensors to maintain independent home-based living for as long as possible. We have identified five frequently problematic areas for the person with dementia that can be supported by technology: Sleep, Activities of Daily Living, Physical Activity, Social Interaction, and Mood. In Dem@Care, a clinical assessment is carried out with the person with dementia and their family to identify their unique needs in each of the 5 areas. An individualised sensor “toolbox” is tailored and discussed with the individual and their family, and an acceptable and useful system is configured and deployed. Over time, information gathered by sensors is used to provide feedback to identify changes in patterns of behaviour that may indicate deterioration, improvement, stasis, or the risk of future deterioration, and to increase awareness of behaviours that are detrimental to health and well-being. We report relevant guiding principles from the literature, and findings from the first Dem@Care pilot evaluation, regarding user-centred design, individualization, ethics, and the acceptability and usability of current Dem@Care sensors. We present results from the monitoring of sleep, physical activity, and daily-living activities and following promising initial results, we are expanding data collection to incorporate additional sensors and new participants with the expectation that we can demonstrate the ability of the Dem@Care system to enable persons with dementia to remain independent and living in their own homes for longer

Nonexotic Neutral Gauge Bosons

We study theoretical and experimental constraints on electroweak theories including a new color-singlet and electrically-neutral gauge boson. We first note that the electric charges of the observed fermions imply that any such Z' boson may be described by a gauge theory in which the Abelian gauge groups are the usual hypercharge along with another U(1) component in a kinetic-diagonal basis. Assuming that the observed quarks and leptons have generation-independent U(1) charges, and that no new fermions couple to the standard model gauge bosons, we find that their U(1) charges form a two-parameter family consistent with anomaly cancellation and viable fermion masses, provided there are at least three right-handed neutrinos. We then derive bounds on the Z' mass and couplings imposed by direct production and Z-pole measurements. For generic charge assignments and a gauge coupling of electromagnetic strength, the strongest lower bound on the Z' mass comes from Z-pole measurements, and is of order 1 TeV. If the new U(1) charges are proportional to B-L, however, there is no tree-level mixing between the Z and Z', and the best bounds come from the absence of direct production at LEPII and the Tevatron. If the U(1) gauge coupling is one or two orders of magnitude below the electromagnetic one, these bounds are satisfied for most values of the Z' mass.Comment: 26 pages, 2 figures. A comparison with the LEP bounds on sneutrino resonances is include

Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm–15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO2 non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring.This work was partly supported through the EU FP7 project SOI-HITS (No. 288481). MTC thanks the Oppenheimer Trust and the EPSRC IAA for their generous financial support.This is the author accepted manuscript. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/apl/106/19/10.1063/1.4921170