2,496 research outputs found

    A 4-D dataset for validation of crystal growth in a complex three-phase material, ice cream

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    Four dimensional (4D, or 3D plus time) X-ray tomographic imaging of phase changes in materials is quickly becoming an accepted tool for quantifying the development of microstructures to both inform and validate models. However, most of the systems studied have been relatively simple binary compositions with only two phases. In this study we present a quantitative dataset of the phase evolution in a complex three-phase material, ice cream. The microstructure of ice cream is an important parameter in terms of sensorial perception, and therefore quantification and modelling of the evolution of the microstructure with time and temperature is key to understanding its fabrication and storage. The microstructure consists of three phases, air cells, ice crystals, and unfrozen matrix. We perform in situ synchrotron X-ray imaging of ice cream samples using in-line phase contrast tomography, housed within a purpose built cold-stage (-40 to +20oC) with finely controlled variation in specimen temperature. The size and distribution of ice crystals and air cells during programmed temperature cycling are determined using 3D quantification. The microstructural evolution of three-phase materials has many other important applications ranging from biological to structural and functional material, hence this dataset can act as a validation case for numerical investigations on faceted and non-faceted crystal growth in a range of materials

    Feasibility of a randomized controlled trial of paediatric interdisciplinary pain management using home-based telehealth

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    Purpose: Chronic pain is common in adolescents. Evidence-based guidelines recommend interdisciplinary treatment, but access is limited by geography. The development of hybrid programs utilizing both face-to-face and videoconference treatment may help overcome this. We developed a 7-week hybrid pediatric interdisciplinary pain program (Hybrid-PIPP) and wished to compare it to individual face-to-face sessions (Standard Care). Our objective was to test the feasibility of a protocol that used a matched pair un-blinded randomized controlled design to investigate the efficacy and cost-effectiveness of the Hybrid-PIPP compared to Standard Care. Patients and Methods: Parent–adolescent dyads were recruited from tertiary pediatric clinics and matched by disability before randomization to minimize allocation bias. The adolescents (aged 11– 17) had experienced primary pain for > 3 months. Hybrid-PIPP involved 11 hrs of group therapy and 4 individual videoconference sessions. Standard care was provided by the same clinical team, using the same treatment model and similar intensity as the Hybrid-PIPP. The intention was to recruit participants for 3 Hybrid-PIPP groups with a comparison stream. Recruitment was ceased after 2 groups due to the high participant disability requiring more intensive intervention. Results: Eighteen dyads were screened and 13 randomized (7 Hybrid-PIPP, 6 Standard Care, 2 unsuitable, 3 unallocated when the study was stopped). The study met a priori feasibility criteria for staff availability; recruitment rate; treatment completion; and data collection. Global satisfaction ratings were similar in both streams (SC median 7, range 5– 9 and Hybrid-PIPP median 8.5, range 5– 10). Challenges were identified in both streams. A future modified Hybrid-PIPP was considered acceptable if the intensity is increased to manage the high level of disability. Standard care was considered inefficient. No adverse events were reported. Conclusion: The study determined that the protocol met a priori feasibility criteria, but to be practicable in a real world, health environment requires significant modifications

    Electromagnetic interferences from plasmas generated in meteoroids impacts

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    It is shown that the plasma, generated during an impact of a meteoroid with an artificial satellite, can produce electromagnetic radiation below the microwave frequency range. This interference is shown to exceed local noise sources and might disturb regular satellite operations.Comment: 6 pages, no figures. This version macthes the published versio

    Nonet Symmetry and Two-Body Decays of Charmed Mesons

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    The decay of charmed mesons into pseudoscalar (P) and vector (V) mesons is studied in the context of nonet symmetry. We have found that it is badly broken in the PP channels and in the P sector of the PV channels as expected from the non-ideal mixing of the \eta and the \eta'. In the VV channels, it is also found that nonet symmetry does not describe the data well. We have found that this discrepancy cannot be attributed entirely to SU(3) breaking at the usual level of 20--30%. At least one, or both, of nonet and SU(3) symmetry must be very badly broken. The possibility of resolving the problem in the future is also discussed.Comment: 9 pages, UTAPHY-HEP-

    Toxicity Evaluation of the Liver and in vitro Metabolism in Wistar Rat on Exposure to N-Nitrosamine Precursors

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    The aim of this study is to evaluate liver toxicity on exposure to n-nitrosamine precursors as well as the effect of ultraviolet light on n-nitrosamines and its precursors. Toxicological evaluation of the liver following single dose treatment of wistar rat with 8.2125 mg NaNO2/adult rat and in rats given a combined dose of 50 mgDMA-HCl and 8.2125 mg NaNO2/adult rat showed a steady elevation of the liver function enzymes. Histopathological analysis of the liver showed hepatic necrosis in the chemical induced rats. Following UV exposure after in vitro incubation of rat liver microsomal plus soluble fraction with NaNO2 and NaNO2 plus DMA-HCl, nitrite concentration in the NaNO2 incubation medium was 19.5 and 2.2 μg/mL before and after UV exposure respectively while the nitrite concentration in the NaNO2 plus DMA-HCl incubation medium was 23.5 and 2.5 μg/mL, respectively. Nitrite loss was significant (p<0.05) between before and after UV exposure in all groups. UV exposure, thus degraded the nitrosamine precursors, nitrite and DMA-HCl, thereby inhibiting possible nitrosation. The high values of the activities of serum transaminases (AST and ALT), alkaline phosphatases (ALP) and gammaglutamyltransferses (γ-GT), relative to control values are indicative of severe intrahepatic cell damag
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