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We use RRKM theory to calculate rate constants and product branching fractions for NH+NO, comparing results for an ab initio surface and two recent empirical surfaces. In addition we compare trajectory and RRKM branching fractions based on the empirical surfaces, including an assessment of zero-point energy effects on branching. Our calculations show that the ab initio and empirical surfaces give
The two lowest potential energy surfaces for C(3P)+NO(2Π) have been investigated. The stationary points were first located using CASSCF gradient calculations and the geometries reoptimized using complete active space second-order perturbation theory. Zero-point corrections have been included in the energetics. In addition to the three linear conformations CNO, NCO and CON, a previously unreported
Self-consistent field ab initio calculations using a previously published, optimized basis set [J. Chem. Phys. 94 (1991) 6677] and second-order Møller-Plesset (MP2) perturbation theory are used in a study of the ArHCl intermolecular potential. The ab initio results are compared to the recently published H6(4, 3, 0) potential-energy surface [J. Phys. Chem. 96 (1992) 4237]. Good agreement is obtaine
Combustion of methane with air in the presence of hydrogen chloride was studied in a turbulent jet-stirred burner. The reaction was monitored by in situ mass spectometry and the ratio of Cl2 2HCl intensities was measured as a function of equivalence ratio (Φ). For values of Φ = 1.25 - 0.5 (fuel rich to fuel lean flames) the ratio of Cl2 2HCl intensities was close to zero. For values of Φ < 0.5 the
An integrated flat-flame/ microprobe sampling quadrupole mass spectrometer system, complemented by optical spectrometry based on optical fibers, is presented. The short microprobe sampling line (total 25 cm) is directly connected to an open ion source closely flanked by two nude cryopumps (900 l/s) yielding a background pressure of 10-9 Torr and a sampling pressure of about 10-5 Torr. Due to this
For the past 30 to 40 years, regulation of the environment has been governed by Environmental Protection Agencies worldwide. During this time we have learned that regulations have significant costs, not just benefits, and that analysis of the cost and benefit of proposed rules is an indispensable component of responsible regulation. Despite present-day recognition of the importance of cost benefit
This study has examined the distribution patterns between gas phase and particle phase of some chemical compounds produced in fires. It has also addressed the question of the distribution of individual particle-associated species between the different size-ranges of particles. The chemical compounds studied and discussed in this paper are polycyclic aromatic hydrocarbons (PAHs), and isocyanates. T
Fires in convalescent homes and elderly care facilities represent a statistically significant threat to their residents, who tend to be less mobile and therefore less able to escape harm. This threat is expected to increase as demographics shift and more people move into this type of facility. A study has been conducted in Sweden to investigate the means by which fire protection and response can b
A number of large-scale fire experiments with detailed quantitative analysis of polycyclic aromatic hydrocarbon (PAH) including PAH congener distribution have been conducted by SP. This data is reviewed here and is further assessed with regard to toxicity applying a Toxic Equivalency Factor (TEF) model for estimation of cancer potential. The PAH yield data from the large-scale fire experiments is
SP Fire Technology is planning the ETANKFIRE research project on ethanol tank firefighting jointly with the Swedish Petroleum Institute. The aim of the ETANKFIRE project is to develop and validate a methodology for fire protection and suppression of ethanol storage tank fires, and to determine the burning behavior of ethanol fuels. Experience from small-scale fires shows that radiation is lower fr
The impact of fires on humans and the environment has been the subject of investigation for decades. We have a variety of more or less well developed models to study the impact of fires on humans and even have several international standards categorising standardised approaches to quantifying the toxic potency of fire gas exposure. However, there is currently no standardised approach available to
The characterisation of fire effluents from large-scale fire tests is important for assessing the risks associated with specific scenarios regarding buildings and transport, and also for validation of effluent data from small-scale tests. This chapter describes some of the most important standard large-scale test scenarios and modifications of these tests including gas analysis. It will further de
Fire-LCA was invented in response to the need for a more holistic LCA of products containing flame retardants. This chapter describes how to conduct a Fire-LCA, illustrated using three product-based case studies: TV sets, furniture and cables. In the TV-set study a US TV was compared with a European TV, the furniture study compared a European sofa with a UK sofa, while two cables with similar fire
Traditional life-cycle assessments (LCAs) of consumer products such as computers, furniture, etc. do not consider the environmental impact of fires involving such products. In so doing, LCA practitioners ignore any benefit from increased resistance to fire through the use of additives as a potential counter-weight to environmental costs of including said chemical. Conventional LCA models include a
For the past 30 to 40 years, well before the concept of sustainable development became politically correct, regulation of the environment has been covered by Environmental Protection Agencies worldwide. Perhaps one of the most important things that we have learned is that regulations have significant costs, not just benefits, and that analysis of the cost and benefit of proposed rules is an indisp
The mass of dioxins, PAH (polycyclic aromatic hydrocarbons) and VOC (volatile organic compounds) emitted from fires to the atmosphere in Sweden per year has been estimated. The estimate is based on the number of fires in buildings, vehicles, waste and forest fires in Sweden in 1999. It is estimated that the total emission of dioxins from fires is in the range 0.5-1.4 g TEQ. The total emissions of
The fire performance of two electric cables (building wires) designed for indoor use has been tested, both as new products and after accelerated thermooxidative ageing. The cables were aged for a maximum time of 16.5 weeks at 80°C. The cables are commercially available, and were constructed using a PVC material in one case and a non-halogenated polyolefin-based material, called Casico, in the othe
For most categories of consumer electrical appliances, UL and IEC standards are typically the only widely used safety standards. A number of these standards are examined to determine if they incorporate technical provisions so that complying products would thereby meet expected fire safety objectives. Specifically, the provisions are examined governing plastic parts in electrical appliances. It is
The environmental impact of products has been increasingly discussed in recent years. In response to questions of the environmental appropriateness of, for example, technologies used to attain a high level of fire safety, a model has been developed to quantify the emissions from fires and include this into a holistic treatment of the environmental impact of a product from the cradle to the grave.
