7,807 research outputs found

    Full-field pulsed magneto-photoelasticity – Experimental Implementation

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    This paper contains a description of the experimental procedure employed when using a pulsed-magneto-polariscope (PMP) and some initial full-field through-thickness measurements of the stress distribution present in samples containing 3D stresses. The instrument uses the theory of magneto-photoelasticity (MPE), which is an experimental stress analysis technique that involves the application of a magnetic field to a birefringent model within a polariscope. MPE was developed for through-thickness stress measurement where the integrated through-thickness birefringent measurement disguises the actual stress distribution. MPE is mainly used in toughened glass where the through-thickness distribution can reduce its overall strength and so its determination is important. To date MPE has been a single-point 2D through-thickness measurement and the analysis time is prohibitive for the investigation of an area which may contain high localised stresses. The pulsed-magneto-polariscope (PMP) has been designed to enable the application of full-field 3D MPE [ ]. Using a proof-of concept PMP several experimental measurements were made, these were promising and demonstrate the potential of the new instrument. Further development of this technique presents several exciting possibilities including a tool for the measurement of the distribution of principal stress difference seen in a general 3D model

    Structural precursor to the metal-insulator transition in V_2O_3

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    The temperature dependence of the local structure of V_2O_3 in the vicinity of the metal to insulator transition (MIT) has been investigated using hard X-ray absorption spectroscopy. It is shown that the vanadium pair distance along the hexagonal c-axis changes abruptly at the MIT as expected. However, a continuous increase of the tilt of these pairs sets in already at higher temperatures and reaches its maximum value at the onset of the electronic and magnetic transition. These findings confirm recent theoretical results which claim that electron-lattice coupling is important for the MIT in V_2O_3. Our results suggest that interactions in the basal plane play a decisive role for the MIT and orbital degrees of freedom drive the MIT via changes in hybridization.Comment: 6 pages, 5 figures, 2 table

    The Utilization of the Solar Energy Through Photochemical Reactions

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    Author Institution: Department of Chemistry, The Ohio State University, Columbus 1

    Pregnancy has a minimal impact on the acute transcriptional signature to vaccination.

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    Vaccination in pregnancy is an effective tool to protect both the mother and infant; vaccines against influenza, pertussis and tetanus are currently recommended. A number of vaccines with a specific indication for use in pregnancy are in development, with the specific aim of providing passive humoral immunity to the newborn child against pathogens responsible for morbidity and mortality in young infants. However, the current understanding about the immune response to vaccination in pregnancy is incomplete. We analysed the effect of pregnancy on early transcriptional responses to vaccination. This type of systems vaccinology approach identifies genes and pathways that are altered in response to vaccination and can be used to understand both the acute inflammation in response to the vaccine and to predict immunogenicity. Pregnant women and mice were immunised with Boostrix-IPV, a multivalent vaccine, which contains three pertussis antigens. Blood was collected from women before and after vaccination and RNA extracted for analysis by microarray. While there were baseline differences between pregnant and non-pregnant women, vaccination induced characteristic patterns of gene expression, with upregulation in interferon response and innate immunity gene modules, independent of pregnancy. We saw similar patterns of responses in both women and mice, supporting the use of mice for preclinical screening of novel maternal vaccines. Using a systems vaccinology approach in pregnancy demonstrated that pregnancy does not affect the initial response to vaccination and that studies in non-pregnant women can provide information about vaccine immunogenicity and potentially safety

    A Review of Bulk Powder Caking

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    The handling and storage of bulk powders is common in many industries such as detergent, pharmaceutical, bulk chemical and food. A lot of materials are susceptible to changes with time that may lead to bulk powder caking, resulting in an unmanageable powder and process downtime, which impacts upon profitability. In this review the current state of the art related to powder caking is explored. The relevant interparticle interactions are discussed with respect to elastic and plastic deformations and the development of liquid and solid bridges due to capillary condensation, sintering and solvent evaporation. The environmental, i.e. temperature and humidity, and the mechanical conditions can heavily influence the transformation of a bulk powder and a number of studies are available that attempt to relate these conditions to caking. A significant amount of work related to the caking behaviour of amorphous powders is available in the literature. Amorphous materials are susceptible to caking due to environmental conditions influencing the glass transition temperature. Once the temperature of amorphous powders exceeds the glass transition, viscous flow occurs and cake strength increases. Crystalline solids may undergo transformations leading to caking. It can take a considerable time and cyclic environmental conditions for caking to occur. However, little research focuses on cyclic conditions and there is limited predictive capability. Finally the options available for attempting to reduce caking propensity are briefly covered and a section that discusses the available caking test methods is given

    ‘Our voice started off as a whisper and now it is a great big roar’ : The Salford Dementia Associate Panel as a model of involvement in research activities

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    This paper presents the work of the ‘Salford Dementia Associate Panel’, based at the Salford Institute for Dementia, Salford University (UK). We discuss the roles of the Dementia Associates, in particular around the areas of engagement and research. The panel is made up of people living with dementia, and current and former care partners. It highlights the development of this group over a four-year period and demonstrates over time how the role of a Dementia Associate member has evolved. The panel is involved in research, education and public engagement activities conducted by staff and students within the Institute. The motivations for becoming involved are clearly articulated and demonstrate how the personal backgrounds of individuals have driven the collective involvement and desire to bring about change. The benefits and challenges associated with working as part of a panel are discussed. We conclude by bringing together our experiences as a set of suggestions for others who may wish to create a similar forum to promote the involvement of people living with dementia and former and current care partners
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