摘要:

AbstractThe synergistic action of antimony (Sb) with bromine (Br) was studied for polypropylene‐2,3‐dibromopropylpentabromophenyl ether–Sb2O3systems at various Sb/Br molar ratios. Oxygen index, weight loss rate and heating value were used to evaluate the retardant effect. Bromine and antimony emission and their material balances were measured by gravimetric and X‐ray fluorometric analysis of heated samples at each reaction time. Retarded HBr formation in the gaseous phase through SbBr3, SbOBr and Sb4O5Br2was proved by X‐ray diffraction analysis of heated residues and model products. SbBr3and HBr formation were greatest at Sb/Br ratios of 1/3 and 1/4, respectively, while the highest oxygen index and the lowest weight loss rate and heating value were obtained at 1/4. Consequently, HBr will most probably produce the retardant effect rather than SbBr3. Effective synergistic action at the Sb/Br ratio of 1/4 is explained by presuming the formation of an acidic HBr.SbBr3complex in the molten phase for the particular reaction pattern of bromine in 2,3‐dibromopropylpentabromoph

ISSN:0308-0501    

DOI:10.1002/fam.810030202

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe role of the product of the thermal properties of thermal conductivity and thermal capacity per unit volume in fire growth is explored in relation to a simple model of a room fire. The calculated differences between flashover times for two different lining materials are plausible; the main conclusion is to show that the flashover time depends onKρCin a weaker relationship than simple proportionality

ISSN:0308-0501    

DOI:10.1002/fam.810030203

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe influence of the various factors that determine temperatures in fire‐exposed concrete slabs is examined, in particular that of material properties. Both experimental and theoretical studies have been carried out. From these a set of thermal properties has been derived that is representative of the properties of siliceous concrete and suitable for use in fire resistance calculation

ISSN:0308-0501    

DOI:10.1002/fam.810030204

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractAdult male Wistar rats were exposed for 2–5 weeks, 6 h nightly, 5 nights a week, to oxidative thermal degradation products of low density polyethylene derived by heating (325°C) under an airstream in a tube oven. Chemical analysis of the degradation products in the gaseous fraction revealed a wide variety of potentially toxic molecules which included carbon monoxide (<20 ppm), formaldehyde (1.4 ppm), acrolein (0.5 ppm) and various other aldehydes (total concentration 18 ppm expressed as formaldehyde). The mean oxygen concentration was 20%. The total particulate fraction amounted to 8 mg m−3. The latter particles might have caused the detected discoloration of the rat fur. Similarly this contamination might have been the cause of a very significant increase in the duration and frequency of preening of the rats. The neurochemical effects associated with the exposure included an increase in the cerebral RNA concentration as well as initial increase in the glycosylation of cerebral proteinin vitro.NADPH‐diaphorase activity was below the control range throughout the exposure while the superoxide dismutase activity displayed an increasing trend five weeks after the beginning of the experiment. The latter effects were taken as a response to potentially harmful molecules in the brain whereas the effects on the RNA and glycosylation might have resulted from a more peripheral nervous irri

ISSN:0308-0501    

DOI:10.1002/fam.810030205

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractWith increasing use of electric trains carrying very high passenger loads it is important to assess the risks involved in using combustible materials. An approach using decision tree methods to analyse the resulting fire growth and passenger action combinations has been developed. Clear statement of objectives, mainly preservation of life and property, is essential. Systems analysis models can then be used to define the nature of quantitative information needed to assess probabilities of the lines of action shown by the decision tree. The current situation is not fully defined since there isdifficulty in using test report and behavioural information in the on‐off mode needed for Boolean logic which is required by decision tree methods. Some preliminary probabilities are given for state transitions, such as ignition to flame spread, based on reported data. A basis for a possible approach to human behaviour variables and the effect of combustion products is give

ISSN:0308-0501    

DOI:10.1002/fam.810030206

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractA study of fire deaths in the Glasgow area has been in operation for 2½ years. Detailed pathological and toxicological examinations have been carried out on 127 fatalities, arising primarily in domestic fires. Cyanide and thiocyanate, the principal metabolite of cyanide in blood, were measured in blood samples from 100 fatalities and from groups of non‐fatal fire casualties, firemen and normal and post‐mortem controls. Cyanide concentrations in the blood of fatal and non‐fatal casualties were elevated to statistically significant levels compared to controls and 6% of fatalities had cyanide levels above 100 μmol 1−1blood. No evidence was obtained for the operation of additive or synergistic effects in fire deaths between cyanide, carbon monoxide and ethyl alcohol. Thiocyanate was of value as an index of metabolized cyanide in non‐fatal subject groups but not in fatalities. Organic volatiles in blood from fire victims were analysed with a gas chromatograph mass spectrometer computer system and for the first time the presence of toxic nitriles other than cyanide has been d

ISSN:0308-0501    

DOI:10.1002/fam.810030207

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThe numbers and severities of burn casualties are described by reference to national data and a more detailed analysis of causes of burns in Birmingham. The important dimensions of any burn are area and depth, both are relevant to severity of injury and mortality. Personal factors, such as age, disability, unconsciousness, drugs and alcohol, can influence depth and area of burning. There is a relation between exposure time and thermal flux to cause burning, this is described for hot metal and radiant heat. The data can be used to predict likelihood of sustaining burns in specified situation. Such prediction is less easy with poor heat conductors; the reasons for this are discussed. The relevance of this information for advising on safety in a variety of situations is outlined.

ISSN:0308-0501    

DOI:10.1002/fam.810030208

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractIn this paper an apparatus is presented by means of which it is possible to measure the ignition time with a very high accuracy, namely 0.01 s. This apparatus has been developed not only for determining the ignition time of fabrics and end products such as curtains, garments, beds, upholstered chairs and toys, but also as an igniting source for use in studying the flame propagation. By using the apparatus it is possible to separate the burning phase from the ignition phase.

ISSN:0308-0501    

DOI:10.1002/fam.810030209

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

摘要:

AbstractThis report describes work currently being carried out at the Fire Research Station, Borehamwood to Study the role of the fire atmosphere in causing incapacitation, injury and death of building occupants in fires. The work includes a detailed study of polymer degradation mechanisms (particularly synthetic) and product formation under carefully controlled laboratory conditions and fires, together with pathological and bioassay(in vivo)work being carried out elsewhere under contract. Analytical studies are reported using gas chromatography and mass spectrometry to identify the complex products formed during the controlled pyrolysis and thermal oxidative decomposition of butadiene‐styrene latex rubber foam, polyacrylonitrile and polypropylene under low (30–400°C), medium (400–650°C) and high (700–900°C) temperature conditions. Studies are reported of the products formed during smouldering and flaming fires in an experimental 0.4 m3fire chamber in an attempt to reproduce conditions relevant to the early stages of fires. In this way, chromatographic fingerprinting of the smouldering products from BS latex rubber foam, and the flaming products of wood wool and polypropylene are given and where possible the major components identified. The relevance of this analytical work in predicting the types of products likely to be encountered during various stages of burning is discussed. General information on the pathological studies and bioassay work being carried out at the Department of Forensic Medicine, University of Glasgow and at the Huntingdon Research Centre respectively are given in order to integrate the overall research programmes and methods of approach being adopted to give an insight into the very difficult area of toxicity

ISSN:0308-0501    

DOI:10.1002/fam.810030210

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810030213

出版商:Heyden&Son Ltd.    

年代:1979

数据来源: WILEY