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This study provides an analysis on the fire safety of passengers and the fire protection of coaches and buses. A brief review of major bus fire incidents, an overview of current regulations in Europe, and their limitations are presented. The study finds that the current small-scale fire test methods described in UN ECE Reg No. 118 need to be replaced by test methods that can assess the reaction to fire of materials when exposed to ignition sources of varying sizes. To address these shortcomings, the study proposed an expert recommendation to update the material fire safety requirements and testing for buses. Additional measures are proposed, derived from objectives and strategies applied in other transport sectors, and can be tested through existing European and international standards, which are widely used by several industries. These measures aim to extend the time with tenable conditions for a safe evacuation in case of fire, reduce the degree of damage to buses, reduce the risk for fast and excessive thermal exposure on modern energy carriers needed for a more sustainable transport sector. [ABSTRACT FROM AUTHOR]

Scheimpflug lidar is a compact alternative to traditional lidar setups. With Scheimpflug lidar it is possible to make continuous range-resolved measurements. In this study we investigate the feasibility of a Scheimpflug lidar instrument for remote sensing in pool flames, which are characterized by strong particle scattering, large temperature gradients, and substantial fluctuations in particle distribution due to turbulence. An extinction coefficient can be extracted using the information about the transmitted laser power and the spatial extent of the flame. The transmitted laser power is manifested by the intensity of the 'echo' from a hard-target termination of the beam located behind the flame, while the information of the spatial extent of the flame along the laser beam is provided by the range-resolved scattering signal. Measurements were performed in heptane and diesel flames, respectively. [ABSTRACT FROM AUTHOR]

The reasons behind the occurrence of a second/end peak heat release rate (PHRR) during wood combustion under radiative heating were determined. Effects of the type of rear material, wood thickness, char progression, and its microstructure, as well as moisture content/transport in spruce wood, were studied. Rear materials used were insulating Kaowool, conducting steel, and the same wood but physically separated from test specimen by aluminium foil. The intensity of the second/end PHRR with Kaowool was almost 50% more than that of the sample with steel. Thus, the second/end peak is governed by the boundary condition defined by the rear material, which determines the heat losses at the rear side of the specimen and consequently the temperature of the specimen. Higher specimen temperature enhances the pyrolysis rate, thereby causing the second/end PHRR. The appearance times and values of the second/end PHRR for 30, 20, and 10 mm wood were 1740 s/78 kWm−2, 685 s/134 kWm−2, and 450 s/160 kWm−2, respectively. Char progressed to the rear of the samples even with a thin (8 mm) conductive steel substrate. Cracks in char grew almost three times wider during the second/end PHRR compared to the sample with no second/end peak. Char cracking had no significance on the time of occurrence of the second/end PHRR but affected the overall heat release. High moisture content reduced the charring rate and delayed the time of occurrence of the second/end PHRR as more water was needed to undergo a phase change, requiring a higher amount of energy. [ABSTRACT FROM AUTHOR]

The mutual inhibition effect of transport of sulfate and chloride in concrete specimens was determined in a macroscopic experiment. A higher concentration of sulfate has a better inhibition effect on chloride transport and the opposite is also true. In this paper, molecular dynamics (MD) simulation was performed to explore the effect of concentration (0, 0.5, 1.0 mol/l) on the transport of mixed solutions (sodium chloride (NaCl) and sodium sulfate (Na2SO4)) in the main hydration products of aluminium-doped cement-based materials (i.e. calcium–aluminium–silicate–hydrate (C–A–S–H) gel). Sulfate was found to promote the aggregation of other ions to form ion clusters, which can reduce the effective width of the channel entrance and create a 'necking' effect, thus reducing the overall transport rate of the solution. With the increase of sodium chloride concentration, sulfate ions in the mixed solution can adsorb more Na+ and Cl− ions, and then form larger ion clusters to block the nanopores. Moreover, with increasing sodium sulfate concentration, a higher amount of sulfate ions existing in the solution makes it possible to form more ion clusters. The results can provide a reasonable nanoscale explanation for macroscopic experiment. [ABSTRACT FROM AUTHOR]

Summary: While there have been various attempts in establishing a model that can predict the flammability characteristics of polymers based on their molecular structure, artificial intelligence (AI) presents a promising alternative in tackling this pressing issue. Therefore, a novel approach of adopting AI methods, extreme learning machines (ELMs) and group method of data handling (GMDH) in estimating heat release capacity, total heat release and char yield from thermophysical properties of polymers were addressed. GMDH showed a clear indication of overfitting whereby the models generated excellent training results but could not provide similar performance during testing. The superior generalisation performance of ELM during testing makes it the standout method. ELM produced HRC predictions having R and RRMSE of 0.86 and 0.405 for training, 0.94 and 0.356 for testing. For THR estimates from ELM, the R and RRMSE scores were 0.9 and 0.195 for training, 0.93 and 0.131 for testing. While char yield ELM model generated 0.88 and 0.795 for training, 0.93 and 0.383 for testing. The potential of ELM was demonstrated as it estimated the flammability parameters of 105 polymers having little or no empirical test results. [ABSTRACT FROM AUTHOR]

In the modern age of nanotechnology, the discovery of graphene has opened up the way to study and develop of several novel 2D materials. The unique physical and chemical properties of 2D materials have enhanced their research, making them superior to the commercial bulk materials used in various applications. Efforts have been made in the current study to present an overview of the intrinsic properties of these materials. Furthermore, synthesis and applications are also reviewed and discussed. Finally, the future outlook of 2D materials is discussed to enhance the research and performance of these materials, which can result in broader applications benefitting the electrical and electronics industries and society. Intensive research into 2D materials is expected to lead to the discovery of new materials with enhanced properties that will benefit the industry and society at large. [ABSTRACT FROM AUTHOR]

Guanyl-urea phosphate (GUP) was introduced into furfurylated wood in order to improve fire retardancy. Modified wood was produced via vacuum-pressure impregnation of the GUP–furfuryl alcohol (FA) aqueous solution, which was then polymerized at elevated temperature. The water leaching resistance of the treated wood was tested according to European standard EN 84, while the leached water was analyzed using ultra-performance liquid chromatography (UPLC) and inductively coupled plasma–sector field mass spectrometry (ICP-SFMS). This new type of furfurylated wood was further characterized in the laboratory by evaluating its morphology and elemental composition using optical microscopy and electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDX). The chemical functionality was detected using infrared spectroscopy (FTIR), and the fire resistance was tested using cone calorimetry. The dimensional stability was evaluated in wet–dry soaking cycle tests, along with the mechanical properties, such as the Brinell hardness and bending strength. The fire retardancy of the modified furfurylated wood indicated that the flammability of wood can be depressed to some extent by introducing GUP. This was reflected in an observed reduction in heat release rate (HRR2) from 454.8 to 264.9 kW/m2, without a reduction in the material properties. In addition, this leaching-resistant furfurylated wood exhibited higher fire retardancy compared to conventional furfurylated wood. A potential method for producing fire-retardant treated furfurylated wood stable to water exposure has been suggested. [ABSTRACT FROM AUTHOR]

The global coronavirus disease 2019 (COVID‐19) pandemic has rapidly increased the demand for facemasks as a measure to reduce the rapid spread of the pathogen. Throughout the pandemic, some countries such as Italy had a monthly demand of ca. 90 million facemasks. Domestic mask manufacturers are capable of manufacturing 8 million masks each week, although the demand was 40 million per week during March 2020. This dramatic increase has contributed to a spike in the generation of facemask waste. Facemasks are often manufactured with synthetic materials that are non‐biodegradable, and their increased usage and improper disposal are raising environmental concerns. Consequently, there is a strong interest for developing biodegradable facemasks made with for example, renewable nanofibres. A range of natural polymer‐based nanofibres has been studied for their potential to be used in air filter applications. This review article examines potential natural polymer‐based nanofibres along with their filtration and antimicrobial capabilities for developing biodegradable facemask that will promote a cleaner production. [ABSTRACT FROM AUTHOR]

3D printing or additive manufacturing (AM) is considered as a flexible manufacturing method with the potential for substantial innovations in fabricating geometrically complicated structured polymers, metals, and ceramics parts. Among them, polymeric composites show versatility for applications in various fields, such as constructions, microelectronics and biomedical. However, the poor resistance of these materials against fire must be considered due to their direct relation to human life conservation and safety. In this article, the recent advances in the fire behavior of 3D-printed polymeric composites are reviewed. The article describes the recently developed methods for improving the flame retardancy of 3D-printed polymeric composites. Consequently, the improvements in the fire behavior of 3D-printed polymeric materials through the change in formulation of the composites are discussed. The article is novel in the sense that it is one of the first studies to provide an overview regarding the flammability characteristics of 3D-printed polymeric materials, which will further incite research interests to render AM-based materials fire-resistant. [ABSTRACT FROM AUTHOR]

Summary: The effect of thermochromic coatings of vanadium dioxide (VO2) on the fire performance of windows was experimentally tested. Prototypes were subjected to radiant heat and the radiation transmitted through the specimens was measured as a function of time. The results indicate that windows coated with VO2 can reduce radiative heat transfer from fires and thereby also reduce or prevent fire spread. The results clearly show that VO2 coatings on BK7 substrates hinder approximately 30% of the transmission of radiation from fire sources when compared with the performance of uncoated windows. It is expected that VO2 will not be solely implemented for the purpose of increasing fire performance of windows, but it will rather provide a secondary positive effect if such windows are realized for energy‐saving purposes. [ABSTRACT FROM AUTHOR]

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We highly appreciate the comments by Vytenis Babrauskas on our recently published article entitled, "The curious case of the second/end peak in the heat release rate of wood: A cone calorimeter investigation" by Sanned et al. However, these processes are quite universal when wood burns, and the focus of our article was how the back-face material affects the timing and intensity of the end peak of the heat release in a cone calorimeter. [Extracted from the article]

The pyrolysis of solid polymeric materials is a complex process that involves both chemical and physical phenomena such as phase transitions, chemical reactions, heat transfer, and mass transport of gaseous components. For modeling purposes, it is important to characterize and to quantify the properties driving those phenomena, especially in the case of flame-retarded materials. In this study, protocols have been developed to characterize the thermal conductivity and the heat capacity of an ethylene-vinyl acetate copolymer (EVA) flame retarded with aluminum tri-hydroxide (ATH). These properties were measured for the various species identified across the decomposition of the material. Namely, the thermal conductivity was found to decrease as a function of temperature before decomposition whereas the ceramic residue obtained after the decomposition at the steady state exhibits a thermal conductivity as low as 0.2 W/m/K. The heat capacity of the material was also investigated using both isothermal modulated Differential Scanning Calorimetry (DSC) and the standard method (ASTM E1269). It was shown that the final residue exhibits a similar behavior to alumina, which is consistent with the decomposition pathway of EVA/ATH. Besides, the two experimental approaches give similar results over the whole range of temperatures. Moreover, the optical properties before decomposition and the heat capacity of the decomposition gases were also analyzed. Those properties were then used as input data for a pyrolysis model in order to predict gasification experiments. Mass losses of gasification experiments were well predicted, thus validating the characterization of the thermo-physical properties of the material. [ABSTRACT FROM AUTHOR]

SUMMARY This work presents measurements meant to study the influence of the spark energy on the time to ignition of a given material in the cone calorimeter. For this purpose, square slabs of particle board were tested under two radiation intensities until ignition occurred using two spark energies for each intensity level. Results show that increasing the spark energy leads to a reduction in the ignition time regardless of the radiation intensity. However, the influence of the spark energy on the time to ignition is, in absolute numbers, larger for the low radiation intensity case than for the high radiation intensity case. Nonetheless, the proportional difference is nearly 10% for both levels of heat radiation. Results from this work confirm that there is an influence of the spark energy on the time to ignition of a given material suggesting that a narrower and more specific definition of the ignition circuits allowed in the cone calorimeter would be highly beneficial for ensuring repeatable results among laboratories. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY Two surface materials for reducing absorptivity of heat radiation from fires have been investigated. The first is VO2, which is a thermochromic material. When the temperature of a VO2 surface increases over a certain temperature, it switches, ideally, from infrared (IR)-absorbing to IR-reflecting. VO2 window coatings are still on a research level, yet to be commercialized. In this study, VO2 powder available on the market was investigated. The thermochromic effect could be identified but was not large enough to significantly improve the fire properties of treated surfaces. Some thoughts concerning how to improve the performance of VO2 are discussed. The second investigated material is indium tin oxide (ITO), which is a so called low-e coating, which means that it has low emissivity and absorptivity in the IR part of the spectrum. ITO is spectrally selective in the sense that it transmits visible light while reflecting a large fraction of the IR radiation, which is a rare property for surfaces in general but a typical property of thin electrically conducting non-metallic films. It is shown that the application of ITO to poly(methyl methacrylate) (PMMA) significantly improves its fire properties. ITO coating is a mature technology already in widespread use today in the electronics industry. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY This work concerns the assessment of fire performance of interior materials in buses. The widely used test method ISO 3795/FMVSS 302 has received much criticism mainly based on the fact that the test is a small-scale method not suited for bus fires induced by for example fire in the engine compartment or fire in a tyre. Furthermore, test specimens are oriented horizontally, whereas much fire spread in a real bus fire occurs on vertically oriented products. Seventeen products were investigated: 11 textiles, four solids and two insulations. Three test methods were compared: ISO 3795, ISO 6941 and ISO 5658-2. Given the existing criteria for interior materials, it was found that ISO 6941 and ISO 5658-2 place harder requirements on the materials. When the three methods were compared, it was found that ISO 3795/FMVSS 302 and ISO 6941 are insufficient for simulating bus fires typically occurring today. Such fires are often initiated by a fire in the engine compartment or in a tyre and can hardly be simulated by small-scale methods as ISO 3795/FMVSS 302 or ISO 6941 even if the ISO 6941 method to some extent gives results similar to the established large-scale ISO 5658-2 method. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The influence of additives on the interaction between radiation from fires and single water droplets has been investigated in detail. A literature study was performed on available information of radiation spectra from different types of fires. Based on this, four reference spectra were proposed that cover most of the different types of radiation that can be expected from fires. These reference spectra were used to compare the effect of different water additives and droplets sizes. Using Mie-theory it was found that increased atomization, down to a diameter limit of 1–10μm, gives a better volumetric absorption efficiency. Decreasing the diameter further does not lead to improved volumetric absorption since the Rayleigh (small droplet) limit is reached, where the volumetric absorption is independent of diameter. Different additives were investigated with respect to increased absorption in the droplets. It was found, however, that it is not trivial to find non-flammable and non-toxic additives that give a significant improvement in absorption. Carbonated water was a potential candidate but the increased absorption was limited to a very weak band centered at 2300cm−1. Since this coincides with the strong CO2 emission band an effect could be seen when carbonated water interacted with radiation from clean flames. The maximum increase in volumetric absorption for carbonated water was 4%, occurring for a droplet diameter of 10μm. Other additives gave better effects but they were either combustible (carbon nanopowder) and/or toxic to some degree. [Copyright &y& Elsevier]

Wavelet multiresolution analysis has been applied to digital images of ethanol sprays injected into air at atmospheric pressure and at room temperature. The imaging was performed with laser-sheet imaging using the 308 nm light from a XeCl excimer laser. Image capturing was performed with a CCD camera. The importance of different scales in the turbulent structure of the sprays was easily recognized using wavelet multiresolution analysis. It was observed that the intermediate and small scale levels contained information of such important phenomena as the spray break-up. This was not easily recognized in the original images, due to averaging over all scales. [ABSTRACT FROM AUTHOR]

The H2 + $$ - \frac{1}{2}$$ O2 ⇌ H2O reaction on platinum at 700 and 1300 K has been studied. A stagnation flow geometry was used with a gas mixture of H2 and O2 at pressures between 0.10 and 10 Torr. Comparing SHG results with simulations using different reaction parameters, it was concluded that $$E_{{\text{H}}_{\text{2}} {\text{O}}}^{\text{f}} \approx 0.7{\text{eV,}}\;E_{{\text{OH}}}^{\text{f}} \approx 0.7{\text{eV}}$$ , and $$E_{{\text{OH}}}^{\text{d}} \approx 2.6{\text{eV}}$$ . LIF measurements showed an ambiguity in the choice of main water-producing channel. Both hydrogen addition with low sticking coefficients and hydroxyl disproportionation with high sticking coefficients are plausible. [ABSTRACT FROM AUTHOR]

Filled hybrid composites are widely used in various structural applications where machining is critical. Hence, it is essential to understand the performance of the fibre composites' machining behaviour. As such, a new hybrid structural composite was fabricated with redmud as filler and sisal fibre as reinforcement in polyester matrix. The composite was then tested for its drilling performance. A comprehensive drilling experiment was conducted using Taguchi L27 orthogonal array. The effect of the drill tool point angle, the cutting speed, the feed rate on thrust force, delamination, and burr formation were analysed for producing quality holes. The significance of each parameter was analysed, and the experimental outcomes revealed some important findings in the context of the drilling behaviour of sisal fibre/polyester composites with redmud as a filler. Spindle speed contributed 39% in affecting the thrust force, while the feed rate had the maximum influence of ca. 38% in affecting delamination. [ABSTRACT FROM AUTHOR]

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 3 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites. [ABSTRACT FROM AUTHOR]

The enhanced carbon footprint of the construction sector has created the need for CO2 emission control and mitigation. CO2 emissions in the construction sector are influenced by a variety of factors, including raw material preparation, cement production, and, most notably, the construction process. Thus, using biobased constituents in cement could reduce CO2 emissions. However, biobased constituents can degrade and have a negative impact on cement performance. Recently, carbonised biomass known as biochar has been found to be an effective partial replacement for cement. Various studies have reported improved mechanical strength and thermal properties with the inclusion of biochar in concrete. To comprehend the properties of biochar-added cementitious materials, the properties of biochar and their effect on concrete need to be examined. This review provides a critical examination of the mechanical and thermal properties of biochar and biochar-added cementitious materials. The study also covers biochar's life cycle assessment and economic benefits. Overall, the purpose of this review article is to provide a means for researchers in the relevant field to gain a deeper understanding of the innate properties of biochar imparted into biochar-added cementitious materials for property enhancement and reduction of CO2 emissions. [ABSTRACT FROM AUTHOR]

Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites' fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications. [ABSTRACT FROM AUTHOR]

Natural fibre-based composites are replacing traditional materials in a wide range of structural applications that are used in different environments. Natural fibres suffer from thermal shocks, which affects the use of these composites in cold environment. Considering these, a goal was set in the present research to investigate the impact of cryogenic conditions on natural fibre composites. Composites were developed using polyester as matrix and jute-fibre and waste Teak saw-dust as reinforcement and filler, respectively. The effects of six parameters, viz., density of saw-dust, weight ratio of saw-dust, grade of woven-jute, number of jute layers, duration of cryogenic treatment of composite and duration of alkaline treatment of fibres on the mechanical properties of the composite was evaluated with an objective to maximise hardness, tensile, impact and flexural strengths. Taguchi method was used to design the experiments and response-surface methodology was used to model, predict and plot interactive surface plots. Results indicated that the duration of cryogenic treatment had a significant effect on mechanical properties, which was better only up to 60 min. The models were found to be statistically significant. The study concluded that saw-dust of density 300 kg/m3 used as a filler with a weight ratio of 13 wt.% and a reinforcement of a single layer of woven-jute-fibre mat of grade 250 gsm subjected to alkaline treatment for 4 h in a composite that has undergone 45 min of cryogenic treatment presented an improvement of 64% in impact strength, ca. 21% in flexural strength, ca. 158% in tensile strength and ca. 28% in hardness. [ABSTRACT FROM AUTHOR]