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5.4 Fire-retardant treated timber A fire-retardant treatment is defined as a chemical/physical method used to stop or slow the spread of fire, either through physically stopping the fire from igniting the wood with subsequent spreading of the flame front or by altering the chemical reactions of combustion. They noted four potential avenues to achieving a reliable FR&P: (1) combine an existing preservative with known FR chemicals, (2) chemical modification of an existing FR chemical with known preservative chemicals, (3) fixing a known preservative that also has FR qualities, or (4) inorganic modification (i.e. ceramification) to form wood-inorganic composites. Keywords: bushfire; fire; fire-retardants; flammability; wildland-urban interface EN bushfire fire fire-retardants flammability wildland-urban interface 679 698 20 08/09/22 20220801 NES 220801 1 Introduction One area where timber continues to be challenged is fire. Standard test method for evaluating the effects of fire-retardant treatments and elevated temperatures on strength properties of fire-retardant treated lumber. 3 Effects of heat on timber Understanding the effects of heating on timber properties in wood-based construction as well as the effects on each cell wall polymer can help in selecting the best methods for chemical protection. [Extracted from the article]

Laser-driven light sources in the extreme ultraviolet range (EUV) enable nanoscopic imaging with unique label-free elemental contrast. However, to fully exploit the unique properties of these new sources, novel detection schemes need to be developed. Here, we show in a proof-of-concept experiment that superconducting nanowire single-photon detectors (SNSPD) can be utilized to enable photon counting of a laser-driven EUV source based on high harmonic generation (HHG). These detectors are dark-count free and accommodate very high count rates—a perfect match for high repetition rate HHG sources. In addition to the advantages of SNSPDs for classical imaging applications with laser-driven EUV sources, the ability to count single photons paves the way for very promising applications in quantum optics and quantum imaging with high energetic radiation like, e.g., quantum ghost imaging with nanoscale resolution. [ABSTRACT FROM AUTHOR]

This paper describes selected observations, measurements, and analysis from a series of large-scale experiments on cross-laminated timber (CLT) slabs that were exposed to fire from below, using four different heating scenarios, with a sustained mechanical loading of 6.3 kN m per metre width of slab. The deflection response and in-depth timber temperatures are used to compare the experimental response against a relatively simple structural fire model to assess the load bearing capacity of CLT elements in fire, including during the decay phase of natural fires. It is demonstrated that the ventilation conditions in experiments with a fixed fuel load are important in achieving burnout of the contents before structural collapse occurs. A mechanics-based structural fire model is shown to provide reasonably accurate predictions of structural failure (or lack thereof) for the experiments presented herein. The results confirm the importance of the ventilation conditions on the fire dynamics, burning duration, and the achievement of functional fire safety objectives (i.e. maintaining stability and compartmentation), in compartments with exposed CLT. [ABSTRACT FROM AUTHOR]

We present a laboratory beamline dedicated to nanoscale subsurface imaging using extreme ultraviolet coherence tomography (XCT). In this setup, broad-bandwidth extreme ultraviolet (XUV) radiation is generated by a laser-driven high-harmonic source. The beamline is able to handle a spectral range of 30–130 eV and a beam divergence of 10 mrad (full width at half maximum). The XUV radiation is focused on the sample under investigation, and the broadband reflectivity is measured using an XUV spectrometer. For the given spectral window, the XCT beamline is particularly suited to investigate silicon-based nanostructured samples. Cross-sectional imaging of layered nanometer-scale samples can be routinely performed using the laboratory-scale XCT beamline. A depth resolution of 16 nm has been achieved using the spectral range of 36–98 eV which represents a 33% increase in resolution due to the broader spectral range compared to previous work. [ABSTRACT FROM AUTHOR]

We present a modular extreme ultraviolet (XUV) spectrometer system optimized for a broad spectral range of 12–41 nm (30–99 eV) with a high spectral resolution of λ/Δλ ≳ 784 ± 89. The spectrometer system has several operation modes for (1) XUV beam inspection, (2) angular spectral analysis, and (3) imaging spectroscopy. These options allow for a versatile use in high harmonic spectroscopy and XUV beam analysis. The high performance of the spectrometer is demonstrated using a novel cross-sectional imaging method called XUV coherence tomography. [ABSTRACT FROM AUTHOR]