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Detection Technology
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
Since flame color can be masked by even small amounts of some common contaminants, these flame tests can be used to confirm the presence of a material, but lack of a positive result cannot be used to rule out a material.
Fire-Retardant Nanocomposite Coatings Based on Nanoclay and POSS
Published in Mangala Joshi, Nanotechnology in Textiles, 2020
P. Santhana Gopala Krishnan, P. Manju, S. K. Nayak
For analyzing the fire retardancy of materials, either the flame behavior or the char residue of the sample can be taken as the choice. Accordingly, the different analyzing techniques can be classified as shown in Fig. 20.6. The flame behavior of materials is studied using tests such as cone calorimetry, underwriters laboratories 94 (UL 94), limiting oxygen index (LOI), thermogravimetric analysis (TGA), vertical flame test (VFT), and furnace test [13–15].
Functionality and Thermophysiological Comfort of Firefighter Protective Clothing
Published in Guowen Song, Faming Wang, Firefighters’ Clothing and Equipment, 2018
The extremely hazardous environments in which firefighters work preclude the use of human subjects in developing and testing protective clothing. Instead, researchers employ laboratory methods such as flame test manikins (Kim, Kim, Lee, & Coca 2017; Li, Shen, & Guo 2016) and flame and radiant test devices (Tessier 2018). Modeling of human physiological responses to different protective systems has become highly sophisticated, including “virtual” computational thermal manikins, physiological models, and thermal comfort analysis (Cheng, Niu, & Gao 2012; Foda, Almesri, Awbi, & Sirén 2011). These models permit safe, rapid evaluation of environments, materials, and protective systems and their structures before prototyping begins.
Flame retardant cotton fabric modified with silica nanosols containing huntite–hydromagnesite grafted with GPTMS and VTES
Published in The Journal of The Textile Institute, 2021
Nurhan Onar Camlibel, Huseyin Topcu
The flammability of untreated and coated fabric samples was evaluated and compared by vertical flame test. Figure 3 exhibits the images of the vertical flame test results on fabrics. The results of vertical flame retardancy test are given in Table 2. It was not observed self-extinguish of flame for cotton fabric samples except VHP1 and GHP2. The untreated cotton fabric was great combustible, can be ignited immediately and burned vigorously with absolutely no char. For the silanes and modified HH deposited cotton fabrics, the flame was weak, flame spreads slowly and significant char was formed, allowing the burned samples to keep their structural integrity, except for samples used APS as oxidative agent in the part of Figure 3d,e. AF and AG time of the fabric coated with modified HH and silanes was prolonged and the flame spreads slowly for especially VHP1 (AF + AG = 12 + 9 = 21 s) and GHP2 (7 + 33 = 40 s) with compare to untreated fabric, which can be attributed to their flame retardant properties (Kaur & Sharma, 2007; Leistner et al., 2015). Hence it indicates that the best flame retardant samples were VHP1 and GHP2 samples. In the study, the good flame retardant properties for cotton fabric were successes with relatively low concentrations of HH (ca. 4 wt%). To increase of the HH amount could further improve the flame retardancy properties of the fabrics.
Study on the Improvement of Methane Explosion Inhibition Effect by Ultrafine Water Mist Containing Methanotroph-inorganic Salt
Published in Combustion Science and Technology, 2022
Ke Yang, Chunxiao Yue, Zhixiang Xing, Hong Ji, Yongmei Hao, Jie Wu, Juncheng Jiang
It can be seen from Figure 9 that under the action of different volume and degradation time, the flame color of methane explosion has changed. The flame in Figure 9a,b,d is bright yellow, the flame changes from bright yellow to light yellow, and then to orange in Figure 9g,c. The flame in Figure 9e,f,h,i finally turned dark yellow. 9.5% pure methane exploded, the flame was light blue, and after first spray, the flame was yellow. The main reason is that the flame color has changed due to the ultrafine water mist and the burning of salt, which proves that the ultrafine water mist has a certain inhibitory effect on the explosion and flame propagation (Yu et al. 2016a). In order to cultivate methanotroph, sodium salt was added into the solution, and the flame was bright yellow under the water mist containing sodium salt. Because of the flame test, after the burning of the sodium atom, the electrons in the atom absorb energy and transition from the lower energy orbit to the higher energy orbit. However, the electrons in the orbit with higher energy are unstable, and quickly jump back to the orbit with lower energy, at which time the surplus energy is released in the form of yellow light. A similar flame reaction occurs in potassium atoms, but the purple light is weak and difficult to observe (Nikolay, Valeri, Sergei 2018). Under the action of first spray, the flame near the ignition end gradually becomes lighter, and in the burned area, the flame color becomes lighter and lighter. The main reason is that the CH4 gas is diluted and the explosion is suppressed under the action of the water vapor that is degraded and evaporated by the ultrafine water mist.
Behavior of fly ash geopolymer as fire resistant coating for timber
Published in Journal of Sustainable Cement-Based Materials, 2019
Faiz Uddin Ahmed Shaikh, Sharany Haque, Jay Sanjayan
Fire temperature of 1100 °C is chosen based on standard hydrocarbon fire curve shown in Figure 6, where the 1100 °C temperature quickly reached in less than 20 minutes. Although cellulosic fire is more appropriate in the case of timber buildings, however, the performance of geopolymer coated timber subjected to 1100 °C is a conservative estimate. Nevertheless the butane flame test is a reasonable analogue to a flame test and has been used by others [14].