22 research outputs found

    Sub-diffractional cavity modes of terahertz hyperbolic phonon polaritons in tin oxide.

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    Hyperbolic phonon polaritons have recently attracted considerable attention in nanophotonics mostly due to their intrinsic strong electromagnetic field confinement, ultraslow polariton group velocities, and long lifetimes. Here we introduce tin oxide (SnO2) nanobelts as a photonic platform for the transport of surface and volume phonon polaritons in the mid- to far-infrared frequency range. This report brings a comprehensive description of the polaritonic properties of SnO2 as a nanometer-sized dielectric and also as an engineered material in the form of a waveguide. By combining accelerator-based IR-THz sources (synchrotron and free-electron laser) with s-SNOM, we employed nanoscale far-infrared hyper-spectral-imaging to uncover a Fabry-Perot cavity mechanism in SnO2 nanobelts via direct detection of phonon-polariton standing waves. Our experimental findings are accurately supported by notable convergence between theory and numerical simulations. Thus, the SnO2 is confirmed as a natural hyperbolic material with unique photonic properties essential for future applications involving subdiffractional light traffic and detection in the far-infrared range

    Prediction of Oil Yield from Oil Palm Mesocarp Using Thermally Assisted Mechanical Dewatering (TAMD)

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    International audienceThermally assisted mechanical dewatering (TAMD) is a new technology for the separation of solid/liquid. When applied to “nature-wet” biomass, the TAMD process significantly enhances the separation yield. In the present study, TAMD was used to extract the crude palm oil (CPO) from mesocarp. The CPO yield of 70.77 wt% was achieved at optimum parameters of 73.0 °C, 6.7 bar and 60 min of extraction time. This CPO yield was comparable with previous works on the enzymatic extraction and hot compressed water extraction (HCWE) with CPO yield of 71.0 and 70.50 wt% respectively. Apart from that, this value was higher for about 13.80% compared to commercial CPO extracted using screw press which obtained the oil yield of 61.0 wt%. Based on the literatures, the highest CPO yield was obtained from supercritical CO2 extraction at 77.0 wt% whereas the lowest CPO yield was extracted using subcritical R134a which gave 66.0 wt% of oil yield. Nevertheless, the operational conditions of supercritical CO2 were 300 bar and 80 °C which were higher than that of TAMD. In conclusion, TAMD extraction has a potential to be an alternative method to extract CPO by producing higher oil yield

    Reliability and Validity of the AOSpine Thoracolumbar Injury Classification System: A Systematic Review

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    Study Design: Systematic review. Objectives: The AOSpine thoracolumbar injury classification system (ATLICS) is a relatively simple yet comprehensive classification of spine injuries introduced in 2013. This systematic review summarizes the evidence on measurement properties of this new classification, particularly the reliability and validity of the main morphologic injury types with and without inclusion of the subtypes. Methods: A literature search was performed using PubMed and Embase in September 2016. A revised version of the COSMIN checklist was used for evaluation of the quality of studies. Two independent reviewers performed all steps of the review. Results: Nine articles were included in the final review, all of which evaluated the reliability of the ATLICS and had a fair methodological quality. The reliability of the modifiers was unknown. Overall, the quality of evidence for reliability of the morphologic and neurologic classification sections was low. However, there was moderate evidence for poor interobserver reliability of the morphologic classification when all subtypes were included, and moderate evidence for good intraobserver reliability with exclusion of subtypes. The reliability of the morphologic classification was independent of the observer’s experience and cultural background. Conclusions: ATLICS represents the most current system for evaluation of thoracolumbar injuries. Based on this review, further studies with robust methodological quality are needed to evaluate the measurement properties of ATLICS. Shortcomings of the reliability studies are discussed
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