On the interpretation of lateral manganin gauge stress measurements in polymers

Encapsulated wire-element stress gauges enable changes in lateral stress during shock loading to be directly monitored. However, there is substantial debate with regards to interpretation of observed changes in stress behind the shock front; a phenomenon attributed both to changes in material strength and shock- dispersion within the gauge-encapsulation. Here, a pair of novel techniques which both modify or remove the embedding medium where such stress gauges are placed within target materials have been used to try and inform this debate. The behavior of three polymeric materials of differing complexity was considered, namely polystyrene, the commercially important resin transfer moulding RTM 6 resin and a commercially available fat lard. Comparison to the response of embedded gauges has suggested a possible slight decrease in the absolute magnitude of stress. However, changing the encapsulation has no detectable effect on the gradient behind the shock in such polymeric systems

Modelling and characterization of cell collapse in aluminium foams during dynamic loading

Plate-impact experiments have been conducted to investigate the elastic–plastic behaviour of shock wave propagation and pore collapse mechanisms of closed-cell aluminium foams. FE modelling using a meso-scale approach has been carried out with the FE software ABAQUS/Explicit. A micro-computed tomography-based foam geometry has been developed and microstructural changes with time have been investigated to explore the effects of wave propagation. Special attention has been given to the pore collapse mechanism. The effect of velocity variations on deformation has been elucidated with three different impact conditions using the plate-impact method. Free surface velocity (ufs) was measured on the rear of the sample to understand the evolution of the compaction. At low impact velocities, the free-surface velocity increased gradually, whereas an abrupt rise of free-surface velocity was found at an impact velocity of 845 m/s with a copper flyer-plate which correlates with the appearance of shock. A good correlation was found between experimental results and FE predictions

Systemic Risk-Shifting in Financial Networks

Banks face different but potentially correlated risks from outside the financial system. Financial connections can share these risks, but also create the means by which shocks can propagate. We examine this tradeoff in the context of a new stylised fact

A Systematic Review of the Effects of Urban Living on Suicidality and Self-Harm in the UK and Ireland

We conducted a systematic review to answer the following: (a) Is there any evidence to support increased prevalence of suicidality and self-harm (i.e. self-harm or suicidality) in urban versus rural environments? (b) What aspects of the urban environment pose risk for suicidality and self-harm? Thirty-five studies met our criteria. Our findings reflect a mixed picture, but with a tendency for urban living to be associated with an increased risk of suicidality and self-harm over rural living, particularly for those living in deprived areas. Further research should focus on the clustering and additive effects of risk and protective factors for suicidality and self-harm in urban environments

Is the content of patient’s written emotional disclosure associated with improved health outcomes for asthma patients?

Written emotional disclosure (WED) is a self-directed, writing intervention. Treatment effects post-WED vary between studies, prompting research into which variables promote the largest improvements. Thus far, research has focused on the frequency of certain linguistic properties of the writing, and subjective stress-related ratings. This study tests the feasibility of using an objective coding framework for stress typology to categorise WED extracts and explores whether any characteristics of the stress described were associated with intervention outcomes. WED extracts from a randomised controlled trial of patients with asthma were coded using an objective stress typology framework. The contents of the WED extracts were reviewed to ascertain whether the experience met the DSM-5 definition for trauma, involved abuse, and was experienced directly or vicariously. Also analysed were the degree of upheaval and upset associated with the event described, together with the time of the event, and number of events written about. Correlational analyses indicated that improvements in asthma-related outcomes were associated with writing about experiences that occurred in childhood, constituted abuse, or caused greater upheaval (all ps <. 05). We found some evidence that the treatment effects of WED may be dependent on what types of stressful experiences participants write about. The use of our objective stress coding scheme was only partially successful as it could not be applied consistently to all WED extracts. Findings require replication using a prospective experimental design

In-Situ Quasistatic Compression and Microstructural Characterization of Aluminium Foams of Different Cell Topology

Quasistatic compression and micro structural characterization of closed cell aluminium foams of different pore size and cell distributions has been carried out. Metallic foams have good potential for lightweight structures for impact and blast mitigation and therefore it is important to find out the optimized foam structure (i.e. cell size, shape, relative density, and distribution) to maximize energy absorption. In this paper, we present results for two different aluminium metal foams of density 0.5 g/cc and 0.7 g/cc respectively that have been tested in quasi-static compression. The influence of cell geometry and cell topology on quasistatic compression behavior has been investigated using computed tomography (micro-CT) analysis. The compression behavior and micro structural characterization will be presented

In-Situ Quasistatic Compression and Microstructural Characterization of Aluminium Foams of Different Cell Topology

Quasistatic compression and micro structural characterization of closed cell aluminium foams of different pore size and cell distributions has been carried out. Metallic foams have good potential for lightweight structures for impact and blast mitigation and therefore it is important to find out the optimized foam structure (i.e. cell size, shape, relative density, and distribution) to maximize energy absorption. In this paper, we present results for two different aluminium metal foams of density 0.5 g/cc and 0.7 g/cc respectively that have been tested in quasi-static compression. The influence of cell geometry and cell topology on quasistatic compression behavior has been investigated using computed tomography (micro-CT) analysis. The compression behavior and micro structural characterization will be presented

The Enthusiast’s Eye: The Value of Unsanctioned Knowledge in Design Historical Scholarship

If design history research relies solely on institutionalized documentation and academic scholarship – that is, sanctioned knowledge – not only will its purview be limited to a very narrow segment of design culture, it will also lose out on a vast array of sources to valuable knowledge about our material environment produced by amateurs, collectors, and enthusiasts – what we in this article define as “unsanctioned knowledge.” Because of its dissociation with professional institutions and academic protocols and their – albeit admittedly utopian, but nonetheless upheld – ideals of objectivity, this type of knowledge is typically considered fundamentally subjective in nature and therefore of little or no relevance and value to academic scholarship. In this article, we argue that, to the contrary, design historical scholarship has much to gain from engaging more seriously with the unsanctioned knowledge represented by the enthusiast's eye