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Polymer dispersed liquid crystal (PDLC) films have potential applications in many aspects due to unique electrically switching properties, and thus the films with excellent comprehensive properties are highly demanded at present. In this study, aromatic polyurethane acrylate (PUA) was used as polymer-matrix, and effect of diluents [lauryl methacrylate (LMA) and isobornyl acrylate (IBOA)] content on the electrical-optical properties of PDLC films was investigated. The results indicate that increase of PUA/LMA or decrease of LMA/IBOA weight ratio increases threshold and saturation voltages (Vth and Vsat), decreases on- and off-state transmittances (Ton and Toff) and increases contrast ratio. Under optimised PUA/LMA weight ratio of 31/19 or PUA/LMA/IBOA weight ratio of 31/15/4, the Vth and Vsat of the films first increase and then decrease with increasing Ag nanowires (NWs) content, and better overall properties are achieved at 0.05 or 0.075 wt.% Ag NWs, respectively. In order to explore essential reasons for the influence of diluents and Ag NWs on the properties of PDLC films, the relationships between film properties (Vth or Vsat, Ton, Toff, and response time) and liquid crystal (LC) droplets size were analysed emphatically, and the changes of system viscosity and anchoring force between polymer-matrix and LC droplets were also discussed. [ABSTRACT FROM AUTHOR]

Gas blowing at the bottom of tundish is an efficient metallurgy technique in clean steelmaking and has been widely concerned. In this paper, spherical alumina particles were selected to model inclusions, 1:3 scale model was utilized, the removal efficiency of inclusions with the gas bottom blowing in the tundish was studied by physical and mathematical modeling. The mathematical model is validated by comparing the predicted and measured residence time distributions and dye flow patterns of tracer. The results show that while the removal efficiency of large size particles has no obvious changes, the gas bottom-blowing has great contribution to the removal of small particles. [ABSTRACT FROM AUTHOR]

Introduction: Positive oral contrast is no longer deemed necessary for abdominopelvic computed tomography (CT) scans. Studies have shown water to be an equally effective oral contrast agent. However, to our knowledge no study has compared effectiveness between gastrografin and water in the same patient, which will provide a more objective evaluation of the two oral contrast agents. We aim to make a head-to-head comparison of water as neutral oral contrast (OC) against gastrografin as positive OC for abdominopelvic CT scans in the same patient., Methods: A retrospective review of 206 abdominopelvic CT scans of 103 patients was performed. The scans were reviewed in consensus by two blinded radiologists. The ability to visualise each abdominopelvic organ, contrastassociated artefacts and small bowel wall delineation, was qualitatively scored on a 5-point scale. Each patient had two sets of scores, one with water and another with gastrografin as OC. Paired scores from the two OCs were evaluated by Wilcoxon signed rank test to determine any significant difference in performance between the two OCs for visualisation of abdominopelvic anatomy on CT., Results: There was significantly better delineation of duodenal wall (p<0.001) and overall visualisation of the duodenum (p=0.011) using water as OC compared to gastrografin. No statistically significant differences were demonstrated between water and gastrografin for visualisation of the rest of the abdominopelvic organs, walldelineation of the rest small bowel and contrast-associated artefacts., Conclusions: Water can be used in place of gastrografin as oral contrast in abdominopelvic CT without compromising visualization of abdominopelvic organs.