bluuebunny/crossref_metadata_2025 huggingface dataset:
Grain structure and texture of cast iron aluminides
Authors: Skrotzki W. , Kegler K. , Tamm R. , Oertel C.‐G.
Published: December 2004

The grain structure and texture of cast iron aluminides have been investigated in the scanning electron microscope by orientation contrast imaging and electron back‐scatter diffraction, respectively. Depending on the aluminum concentration the alloys exhibit a fine‐grained chill zone, medium grain size columnar zone and/or coarse‐grained equiaxed zone. The texture is random except in the columnar zone which is characterized by a <100> fibre texture in the direction of heat flow, i.e parallel to the elongated grains. The development of grain structure and texture is discussed with respect to cooling rate, thermal and constitutional undercooling, and order. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation of structural and physical properties of metastable Fe‐Cr phases
Authors: Gorbunov A. , Levin A. A. , Meyer D. C. , Bischoff L. , Eckert D. , Köhler B. , Mertig M. , Weißbach T. , Wieser E. , Pompe W.
Published: December 2004

This paper contributes to the studies of physical properties of metastable Fe‐Cr phases which have been discovered recently in the thin films deposited from the hyperthermal Fe and Cr particle beams. The electrical resistance and the magnetic remanence are correlated with the crystallographic parameters and phase composition of the samples. It is demonstrated that the focused ion‐beam induced phase transformation in the unusual metastable Fe‐Cr alloys can be used for the fabrication of ferromagnetic arrays. © 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Preparation of aluminosilicate crystalline coatings from sol‐gel derived alumina films deposited on silicon/silica substrates
Authors: Gutmann E. , Levin A. A. , Pommrich I. , Meyer D. C.
Published: December 2004

The dedicated formation of crystalline coatings of the trimorphous aluminosilicates with the composition of Al2SiO5 starting from a low‐cost sol‐gel deposition of alumina thin films is reported. The influence of substrate type and film thickness on the crystallisation behaviour and film morphology is studied by means of wide‐angle X‐ray scattering (WAXS) and X‐ray reflectometry (XR). When annealed at a temperature of 1150 °C under high‐vacuum conditions, formation of the aimed phases was achieved only for films deposited on naturally oxidised Si‐substrates covered with a thin silica layer (thickness is about 3 nm). In the case of films deposited on amorphous quartz glass and thermally oxidised Si‐substrates covered with a thick silica layer (thickness is about 500 nm) no crystallisation occurred at this temperature. After annealing at the higher temperature of 1300 °C under high‐vacuum conditions, in the films deposited on both kinds of Si‐substrates mullite (Al4SiO8) crystallises together with cristobalite (SiO2) whereas the film deposited on the quartz glass substrate remains amorphous from viewpoint of WAXS. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Human monocyte CD163 expression inversely correlates with soluble CD163 plasma levels
Authors: Davis Bruce H. , Zarev Petar V.
Published: December 2004

Background

CD163 is a monocyte/macrophage‐restricted receptor involved in the clearance of hemoglobin–haptoglobin complexes and regulation of inflammatory processes. CD163 is shed from the cell surface and exists as a soluble form in plasma (sCD163). Monocyte CD163 and sCD163 are potential diagnostic tools in variety of disease states.

Methods

We determined the relation between plasma sCD163 levels by enzyme‐linked immunosorbent assay, membrane expressions of CD163, CD64, and CD14 on blood monocytes by flow cytometry, and monocyte counts in 129 random blood samples.

Results

A strong inverse correlation was found between membrane CD163 expression and sCD163 levels (r = −0.65, P < 0.001). Monocyte CD163 expression and SCD163 levels did not correlate with the monocyte absolute count.

Conclusions

The inverse relation between monocyte surface CD163 expression and sCD163 levels in human blood suggests that plasma sCD163 is derived from circulating monocytes, in addition to an unknown component from tissue macrophages. The lack of correlation with the absolute monocyte number suggests that such a balance is driven by the functional state of monocytes, rather than simply by numerical changes in circulating cells. We propose that further clinical evaluations of CD163 as a diagnostic parameter should include simultaneous measurements of soluble and cell‐bound forms of this antigen. © 2004 Wiley‐Liss, Inc.
Fixation and cryopreservation of whole blood and isolated mononuclear cells: Influence of different procedures on lymphocyte subset analysis by flow cytometry
Authors: Pinto Ligia A. , Trivett Matthew T. , Wallace Dora , Higgins Jeanette , Baseler Michael , Terabe Masaki , Belyakov Igor M. , Berzofsky Jay A. , Hildesheim Allan
Published: December 2004

Background

Immunophenotyping of whole blood (WB) and isolated peripheral blood mononuclear cells (PBMCs) is a common tool used to evaluate immune system changes in clinical studies. The development of methods that would allow preservation of samples for flow cytometric analysis is important for the extension of this technology to field testing in settings where the equipment might be not readily accessible.

Methods

Three‐color flow cytometric analysis was used to determine percentages of T cells and their subsets (CD3+, CD4+, CD8+), B cells (CD19+), and natural killer cells (CD16+/56+) in WB and PBMCs using variations of a standard stain/fix WB staining procedure (Optilyse) that included staining following fixation and freezing of fixed samples before or after staining.

Results

Comparable lymphocyte subset percentages in WB or PBMCs were observed regardless of Optliyse method used (all Ps ≥ 0.8). However, differences in fluorescence intensity for several markers were observed across procedures. Compared with the standard stain/fix procedures, fix/stain decreased the mean fluorescence intensities for CD4, CD8, CD19 and CD16/56 in WB and PBMCs (P ≤ 0.03 for these markers P = 0.105 for CD8 in PBMCs). Further decreases in mean fluorescence intensity were seen with the fix/stain/freeze procedure. The stain/fix/freeze yielded intensities largely comparable to those seen with standard stain/fix procedure (P ≥ 0.13), suggesting that, when the markers of interest are known at the time of field collection, implementation of this procedure might be desirable. Fix/freeze/stain resulted in diminution of intensity in general, but they tended to be more modest than those seen for fix/stain/freeze and therefore might be applicable to field studies in instances when the specific markers of interest cannot be defined upfront.

Conclusions

Freezing of fixed WB and PBMCs before or after cell surface staining is a reliable method for preserving specimens in field sites for later determination of lymphocyte subset percentages, which are commonly assessed in immunodeficient and cancer patients. Published 2004 Wiley‐Liss, Inc.
Fire testing of upholstered furniture and bedding
Authors: Paul K. T.
Published: December 2004

Considerable concern has been expressed about the increasing number and changing pattern of fires and the fact that modern upholstered furniture is relatively easy to ignite and, once ignited, burns rapidly to produce large quantities of smoke and toxic gas. This led to a number of major research programmes and to the evolution of a number of test procedures in the UK. The first major test procedure was published in 1976 by the BPF in conjunction with RAPRA, BRMA and FIRA. An important aspect of this approach was the linking of ignition and rate of initial burning data with the application of the product and the environmental hazard. It was evolved within a short period of time to proved furniture designers and specifies with a means of avoiding products of high risk. The DOE/PSA are using a comprehensive series of Fire Retardant Specifications to control and specify their upholstered furniture and bedding. Specifications have been developed which enable individual components and sub‐assemblies as well as the final product to be characterized in terms of ignitability and burning characteristics, i.e. temperatures, smoke, and carbon monoxide production. BS DD58 and BS 5852 Part1, ignitability tests for upholstered seating are essentially a combination of BPR and DOE/PSA test procedures. Cigarettes, gas flames and wooden cribs are used for the ignition sources and are positioned on a composite seat/back test rig.
Fire test behaviour of various crystal types of melamine phosphate in intumescent formulations
Authors: Kay M. , Price A. F.
Published: December 2004

Melamine orthophosphate crystals vary in shape and formula according to their method of production. The types vary widely in their behaviour when incorporated into an epoxy resin intumescent coating for trials in a small scale fire test. Heat treatment of melamine phosphate crystals at 210 °C, a process designed to reduce their solubility, profoundly affects the performance of any crystal type in a fire test. In such cases crystal shape alone appears to determine performance, whereas the shape, formula, and state of agglomeration affect performance in coatings produced with untreated melamine phosphate. Small plates of side 20 μm heat treated at 210 °C, are the preferred type for optimum performance and weathering characteristics.
Statistics of fires in dwellings involving textiles in the United Kingdom
Authors: Mahon B. H. , Hills M. L.
Published: December 2004

There is widespread concern at present about the fire risk form the use of modern materials in upholstery and other domestic articles. One of the main characteristics of fires in dwellings which start with the ignition of textiles or furniture is that they have a high casualty rate compared with other kinds of domestic fires. Most of the casualties form such fires occur in fires which start in upholstery or bedding, often accidentally ignited by smokers' materials. Asphyxiations by smoke is the commonest cause of death in ‘textile’ and ‘upholstery’ fires. This paper presents relevant statistical information on fires in dwellings attended by local authority fire brigades which result from the ignition of upholstery, bedding, other textiles or furniture and the casualties which these fires cause.
Flame‐retardant paints
Authors: O'Neill L. A.
Published: December 2004

Flame‐retardant paints have been developed which can considerably upgrade the performance of combustible substrates in surface spread of flame test, but there is uncertainty as to their benefit in a real fire situation. This is partly owing to the lack of agreement on laboratory test methods and even of their value. Flame‐retardant paints commercially available in the United Kingdom are of two types, the intumescent type and the antimony oxide type, and their mechanism of action is discussed.
The performance of various testing columns in small‐scale horizontal burning studies
Authors: Wharton R. K.
Published: December 2004

The use of Critical Oxygen Index testing columns in the horizontal configuration is investigated. Gas analysis results from within columns of simple design indicate that they are unsuitable for burning studies because of entrainment of the external atmosphere and recirculation of combustion products. A new design of column and holder is proposed that eliminates these effects and provides a possible means of studying small‐scale horizontal combustion in different oxygen/nitrogen mixtures.
Zirpro wool textiles
Authors: Benisek L.
Published: December 2004

The overall flammability hazard of Zirpro wool protective clothing, carpets and upholstery with regard to national and international standards is summarized. Protective clothing against heat and flames has to be evaluated not only for flame‐retardance by a vertical flame test but also for heat transfer from convective (flames), radiant and conductive (molten metal) heat exposure to ensure a realistic assessment of the potential protective offered and required. Textile furnishings (carpets, upholstery, curtains) have to be evaluated for flame‐retardance, heat release, smoke emission and toxicity of combustion products to assess the overall flammability hazard. Evaluation and consideration of only on e flammability parameter, e.g. toxicity of combustion products, can lead to misleading conclusions about the flammability hazard of a material.
Small‐scale experiments of flame spread in pre‐flashover compartment fires
Authors: Takeda Hisahiro
Published: December 2004

Some early stages of compartment fires were explored experimentally using small‐scale model fires. In particuylar, the flame spread on the compartment floor was investigated with various ventilation openings. The average flame‐spread rate was higher than that for the free‐burning condition (without a compartment),namely, 3.2 times at the maximum, and seems to depend only on the ventilation opening height and not on its width. Therefore it appears that the driving wind of the inflow air from the ventilation opening to the flame increase‐spread rate. These data were compared with the flame angle data by Quintiere. The gas temperature within the compartment and the ceiling surface temperature was also measured to assess the radiation effect on flame spread. However, the radiation heat flux was unexpectedly small.
The use of DTA to study spontanceous ignition of cellulose
Authors: Horrocks A. R. , Davies D. , Greenhalgh M.
Published: December 2004

The use of differential thermal analysis has enabled spontaneous ignition behaviour of cotton cellulose to be investigate. The temperature. Ti, at which the onset of spontaneous ignition occurs is recorded as a function of the oxygen concentration of the flowing oxygen‐nitrogen atmosphere to which the cellulose sample is exposed in the DTA furnace, when heated at a defined heating rate. The dependence of Ti, on heating rate has enabled the activation energy, Ep, of the rate‐determining flammable pyrolysis product reaction to the determined using both a previously derived simple kinetic model and the technique of Ozawa. Ep, increases from a lower limiting value of 112 kJ mol−1 at zero oxygen concentration to an asymptote value of 169 kJ mol−1 at oxygen volume concentrations above 30%. This effect is described in terms of oxygen catalysis of competing pyrolysis routes. At a given heating rate, increased oxygen concentration reduces Ti. A plot of 1/Ti versus In [O2] gives two liner regions which intersect at an oxygen concentration of about 20%, suggesting that two combustion mechanisms exist, one above and the other below this value. Below this concentration, which is similar to the conventional limiting oxygen for cellulose, significant char remains, suggesting that ignition of gaseous products only occurs. If the difference in slopes is sttributed to the variations in Ep with oxygen concentration, then a value for the activation energy of gaseous product oxidation, Eox = 215 kJ mol−1 is derived.
Smoke and toxicity
Authors: Smith D. A.
Published: December 2004

Smoke and toxic gases (STG) are the main cause of fire deaths. They combine to make escape difficult and to retard rescue work and fire‐fighting. The paper reviews advances in the characterization of the STG hazard, and discusses improved materials of construction to meet the new, more stringent safety criteria used by responsible architects and design engineers. Because of the wide choice of safer materials now available at reasonable cost in a number of product areas such as furniture foams and cable insulation, the time is approaching when such materials can be introduced without harming the economics of these industries. Indeed, a convincing demonstration of intrinsic safety could without harming the economics of these industries. Indeed, a convincing demonstration of intrinsic safety could encourage the introduction of improved plastics and other organic materials into a wide range of market applications.
Effect of flame retardants on polyolefines
Authors: Rychlý J. , Rychlá L.
Published: December 2004

Phosphorus and Bromine flame retardants decrease the time of self‐ignition delay and increase the mass rate of burning of polypropylene even though the limiting oxygen index (LOI) at ambient temperature is higher. The proposed model which combines ignition, steady burning and extinction shows that the phenomenon can be explained only by an increased rate of polymer volatilization caused by flame retardant.
The corrosiveness of fluoride‐containing fire gases on selected steels
Authors: Sandmann H. , Widmer G.
Published: December 2004

Combustion gases were produced from several cable‐insulation materials in separate experiments conducted in a model fire chamber. These gases were then allowed to interact with stressed metal specimens, consisting for the most part of various stainless and hardened steels as well as of carbon steel and stainless steel sheet. Thereafter the samples as exposed were stored in a humid atmosphere. As expected, PVC combustion gases caused the cracking of spring steel and also extensive pitting corrosion of stainless steel. These results confirmed that test conditions conformed to real‐life fires as observed in practice. The combustion gases deriving from fluorinated polymers were much less corrosive on stainless steel and provoked only slight pitting in isolated cases. The rate of corrosion damage on carbon steel was lower by more than an order of magnitude than in the case of PVC. However, stress corrosion of sensitized 18/8 stainless steel and spring steel was found to occur. Tests on the thermal degradation of the dluorinated polymer ‘Teflon’ FEP and ‘Tefzel’ confirmed their high stability. If one compares the behaviour of these fluoroplastics with that of PVC it can generally be concluded that, although the use of fluorinated insulation materials on cables might not altogether eliminate corrosion problems in the event of fire, it does constitute a realistic contribution to fire protection and to the reeducation of fire‐related damage.
Polyesters: A review of the literature on products of combustion and toxicity
Authors: Braun Emil , Levin Barbara C.
Published: December 2004

The available literature was reviewed to determine the nature and extent of information available on the thermal decomposition products and the toxicity of the combustion products of polyester materials used in consumer applications such as textiles and building construction. This literature review is limited to those publications printed in English through June 1984. The thermal decomposition products of polyesters are a function of temperature and oxygen content of the atmosphere. In general, as the temperature increases, the quantity of heavier hydrocarbons decreases and the production of CO and CO2 increases. The presence of flame retardant additives, such as bromine and chlorine‐containing compounds, produce halogenated combustion products. The use of phosphorus and bromine together in the same flame retardant finish increases the concentration of low molecular weight compounds. Thirteen different test protocols have been used to evaluate the toxicity of various types of polyester. Non‐flame retarded polyesters give measured LC50 values ranging from 30.5 Mgl−1 to 95.7 mgl−1, while flame retarded polyesters, have LC50 values ranging from 24.0 mgl−1 to 38.0 mgl−1. Several exceptions, however, are noted. Toxicologists consider these differences to be not significant. In general, the results from large‐scale tests are ambiguous because of the presence of other materials in addition to the polyesters.
A suggested logic for trading between fire‐safety measures
Authors: Harmathy T. Z.
Published: December 2004

A simple logic is presented for expressing the equivalence of fire safety measures. It is based on the principle that any combination of safety measures is acceptable as long as it does not lead to losses (property and human losses) above the level accepted by society.
A review of the literature on the gaseous products and toxicity generated from the pyrolysis and combustion of rigid polyurethane foams
Authors: Paabo Maya , Levin Barbara C.
Published: December 2004

The literature on rigid polyurethane foam has been reviewed with an emphasis on the gaseous products generated under various thermal decomposition conditions and the toxicity of those products. This review is limited to publications in English through 1984. Carbon monoxide (CO) and hydrogen cyanide (HCN) were the predominant toxicants found among more than a hundred other gaseous products. The generation of CO and HCN was found to increase with increasing combustion products from various rigid polyurethane foams. Lethality, incapacitation, physiological and biochemical parameters were employ as biological end points. In general, the combustion products generated from rigid polyurethane foam in the flaming mode appear from to be more toxic than those produced in the non‐flaming mode. The LC50 values for 30‐min exposures ranged from 10 to 17 mg l−1 in the flaming mode and were greater then 34 mg l−1 in the non‐flaming mode. With the exception of one case, in which a reactive type phosphorus containing fire retardant was used, the addition of fire retardants to rigid polyurethane foams does not appear to generate unusual toxic combustion products.
The formation of hydrogen cyanide during methacrylonitrile pyrolysis
Authors: Metcalfe E. , Harman A. R. , Fardell P. J.
Published: December 2004

This short note describes studies of the pyrolysis of methacrylonitrile over a wide range of temperatures under flowing nitrogen at atmospheric pressure. Hydrogen cyanide was not found to be a primary product, but several organic nitriles are formed which decompose at higher temperature (> 1100 K) to produce hydrogen cyanide almost quantitatively.
Nylons: A review of the literature on products of combustion and toxicity
Authors: Braun Emil , Levin Barbara C.
Published: December 2004

The literature on polyamides was reviewed to determine the nature and extent of information available on these materials which are commonly used in consumer and industrial applications. This review was limited to aliphatic polyamides normally called nylon and excludes aromatic polyamides such as Nomex and bicomponent polymers consisting of nylon and other polymers. The review was further limited to those publications in English through June 1984. Typical pyrolysis products from a broad range of nylons do not appear to differ greatly. Many of the decomposition products detected in vacuum pyrolysis experiments appear as products of thermal degradation in inert and air atmospheres. In air, a general reduction in the quantities of heavier hydrocarbons is noted along with an increase in the production of CO, CO2, H2O, NH3, HCN and NOx. The toxicity of the thermal degradation products from various types of nylon has been evaluated by nine different protocols. Reported LC50 values range from 10.8 m l−1 to 61.9 mg l−1. Dyes apparently do not affect the materials' combustion products toxicity but an increase in the amount of backcoating on a nylon fabric increases toxicity. Time to death measurements show that volatile products from nylons are less toxic than those from rayons or cotton, while the blending of wool with nylon greatly increases the toxicity of the thermal decomposition products. In general, however, the overall toxicity of the thermal degradation products from nylon do not appear to be greatly different than those from many other polymeric materials. Large‐scale test results are ambiguous, and it is difficult to interpret the results in terms of a single component in a multicomponent system.
Toxicity of the pyrolysis and combustion products of poly(vinyl chlorides): A literature assessment
Authors: Huggett Clayton , Levin Barbara C.
Published: December 2004

Poly(vinyl chlorides) (PVC) constitute a major class of synthetic plastics, Many surveys of the voluminous literature have been performed. This report reviews the literature published in English from 1969 through 1984 and endeavors to be more interpretive than comprehensive. PVC compounds, in general, are among the more fire resistant common organic polymers, natural or synthetic. The major products of thermal decomposition include hydrogen chloride, benzene and unsaturated hydrocarbons. In the presence of oxygen, carbon monoxide, carbon dioxide and water are included among the common combustion products. The main toxic products from PVC fires are hydrogen chloride (a sensory and pulmonary irritant) and carbon monoxide (an asphyxiant). The LC50 value calculated for a series of natural and synthetic materials thermally decomposed according to the NBS toxicity test method ranged from 0.045 to 57 mg l−1 in the flaming mode and from 0.045 to > 40 mg l−1 in the non‐flaming mode. The LC50 results for a PVC resin decomposed under the same conditions were 17 mg l−1 in the flaming mode and 20 mg l−1 in the non‐flaming mode. These results indicate that PVC decomposition products are not extremely toxic when compared with those from other common building materials. When the combustion toxicity (based on their HCI content) of PVC materials in compared with pure HCI experiments, it appears that much of the post‐exposure toxicity can be explained by the HCI that is generated.
Fire‐resistant coatings for roof/ceiling deck timbers
Authors: Richardson L. R. , Cornelissen A. A.
Published: December 2004

Laboratory tests demonstrated that the intumescence resulting from application of some proprietary flame‐retardant paint and coating systems to timber planks could reduce char formation in the planks by as much as 70% during the first 30 min of exposure to ASTM E–19 fire conditions. Applications of these coating systems to the exposed surfaces of planks used in construction of heavy timber building assemblies should increase the fire resistance of these components by at least 30 min. This would represent a significant increase in the fire resistance of heavy timber roof systems and could extend the use of this type of construction system to many of the non‐residential buildings for which building code authorities presently require fire resistance ratings greater than 1 h.
Fire‐Resistant joints in gypsum wallboard
Authors: Richardson L. R. , Venasse R. G.
Published: December 2004

In situations where joint failure in the protective gypsum membrane is critical to the fire resistance of the system, wallboard manufacturers recommend application of two layers of wallboard with joints in the face layer staggered with joints in the backerboard. Unfortunately, the additional weight load that a second layer of wallboard imposes on the building assembly renders the technique impractical in some situations. Two examples are wallboard ceilings attached directly to wood joist or wood truss floor systems or suspended by hanger wire to steel furring channels below these floor systems. Small‐scale laboratory tests demonstrated that the installation of steel ‘Tee’ strips in the finished joint between adjacent gypsum wallboard panels significantly increased the resistance of the joint to passage of fire and hot gases. Use of these strips in the construction of gypsum wallboard protected building systems should provide a significant increase in the fire resistance of the entire assembly without greatly increasing the weight load imposed upon the assembly.
Classification of reaction‐to‐fire of decorative high‐pressure laminates (HPL)
Authors: Probsthain K.
Published: December 2004

Decorative high‐pressure laminates (HPL) are used in many applications where their reaction‐to‐fire is of particular interest. They form finishes of walls and ceilings in buildings, ships and vehicles. Due to the different specifications and regulations in these fields, different grades of this largely standardized material have been tested worldwide with similar results. As a consequence, German and French building regulations state decorative high‐pressure laminates to be generally admissible on a minimum level without individual testing. This survey indicates their generic suitability in other fields, e.g. to have ‘low flame‐spread characteristics’ according to the International Convention for the Safety of Life at Sea.
Toxicity of the combustion and decomposition products of polyurethanes
Authors: Prager F. H. , Kimmerle G. , Maertins T. , Mann M. , Pauluhn J.
Published: December 2004

The acute toxicity by inhalation of polyurethane combustion and decomposition products was investigated by means of animal experiments. The results demonstrated that previous regulative and normative approaches which are based on the chemical nature of the materials tested and the analytically determined concentration data for major fire gas components are inconsistent with the research findings set out in TR 9122 of ISO TC92 SC3. The animal experiments, which complied with the test and assessment criteria put forward by the experts of ISO TC92 SC3 ‘Toxic Hazards in Fire’, provided convincing evidence that the overall toxic potency of the decomposition products released by polyurethane foam and PU coatings under comparable fire conditions was the same as for wood or wool. It was found that the acute toxic hazard potential of combustion gases is determined by the concentration of toxic components in the fire effluents (which in turn depends on the quantity of material burned in unit time) and by local conditions. This means that all parameters capable of affecting the combustion process are critical.
Effects of metallic coating on the combustion toxicity of engineering plastics
Authors: Larsen James B. , Nelson Gordon L. , Williams Brian K. , Spencer Eric G. , Spencer Lisa M.
Published: December 2004

Experiments were conducted on 34 plastic materials having a variety of metallic coatings to determine the toxicity of their thermal decomposition products. Mice were exposed for 30 min in a dome exposure chamber to the products obtained by ramp‐heating the samples from 200°C to 800°C. An LC50 value was obtained for each material. Postmortem examinations were conducted on all dead mice, and on survivors after 14 days, to determine the gross pathological effects of exposure; particular attention was devoted to pulmonary pathology. The exposure protocol chosen has been extensively criticized, but it is very useful to study the effects of stress on mice, which was the most important part of this work. Experiments were made involving unrestrained mice in groups of four, restrained mice in groups of four and unrestrained single mice. The LC50 values for single unrestrained mice were greater, by factors of 2–3, than those for four restrained mice, with the differences being shown to be statistically significant. This suggests that stress on the test animals will tend to reduce the LC50 values in bench‐scale smoke toxicity tests. The LC50 values for all of the materials tested were equal to or higher than the value of 8 mg1−1 representative of the contribution of carbon monoxide to post‐flashover fires. Moreover, no ‘supertoxicants’ were found in the smoke of any of the materials tested. Finally, the coatings did not adversely affect the smoke toxicity of the substrate materials by a factor higher than 2–3 in any of the cases investigated. Uncoated polyethylene was the most toxic substrate material tested (LC50 = 16 mgl−1) and uncoated NORYL® resin was the least toxic (LC50 = 91mgl−1). Metallic coatings involving Cu, Ni, graphite, and Zn typically had no statistically significant effect on the smoke toxicity of the substrate materials, although Ni coatings increased the smoke toxicity of ABS I and of white polycarbonate structural foam, by factors of 2–3. Overall smoke toxicities were well correlated with production of carbon monoxide (r=0.84) and carbon dioxide (r=0.82); oxygen levels and chamber temperature did not vary beyond acceptable limits. The materials tested generating the more toxic smokes (including polyethlene, polystyrene, and several polycarbonates) produced severe lung damage at low concentrations. The LC50 of these materials was also typically greater than predicted on the basis of CO production. Other materials (including several coating on NORYL® resin and Lexan® polycarbonate) produced pulmonary damage at higher concentrations amd had LC50 values more closely correlated with CO production. None of the polyurethane materials tested produced severe lung damage at the concentrations employed.
Fire‐hazard assessment of extended‐chain polyethylene and aramid composites by cone calorimetry
Authors: Brown J. R. , Fawell P. D. , Mathys Z.
Published: December 2004

A cone calorimeter is used to determine the fire performance of polymer composite materials containing combustible reinforcing fibres in addition to combustible matrix resins. Extended‐chain polyethylene and aramid fibre‐reinforced composites containing epoxy, vinylester and phenolic matrix resins are examined at various cone irradiances. Values for time to ignition, rate of heat release, effective heat of combustion, smoke density and evolved carbon monoxide and carbon dioxide are reported for the reinforcements, matrix resins and composites. The reinforcements have a significant effect on the fire‐hazard properties of the composite materials. For the epoxy and vinylester composites, times to ignition reflect those of the component of higher ignitability. This was not the case for the aramid‐reinforced phenolic composite, in which the resin surface layer hinders combustion of the fabric reinforcement. Resin and reinforcement contributions to the composite rate of heat release behaviour as a function of time are generally discernible.
Evaluation of residual fire endurance of concrete slabs after fire exposure
Authors: Hsiung Kuang‐Hua , Chang Weilin P.
Published: December 2004

One of the important factors that must be considered in evaluating the integrity of structures for further use after exposure to fire is whether the fire endurance of specific structural elements or a structural assembly has been reduced to a value less than that required by the building code. While a building may appear to remain structurally sound after a fire, its structural members' fire endurance may have been impaired to the extent that occupancy cannot be permitted. Re‐usability of concrete structures after fire is of economic concern to the owner, especially when there is no visible damage to the structural members. The objective of this research is to conduct a small‐scale pilot study and use statistical analysis to investigate the possible cause‐and‐effect relationships of three factors on the residual fire endurance: exposure severity, recovery conditioning method, and recovery conditioning time lapse. This research provides information for predicting fire endurance loss of concrete slabs after exposure to fire and, as a consequence, for making decisions on the re‐usability of the structure. The research results indicate that once the concrete slabs (102 mm thick, no reinforcement and no load) are exposed to a standard fire for more than 30 min their fire endurance will decrease by at least 20%.
Describing product fire performance—manufacturers' versus modelers' needs
Authors: Babrauskas Vytenis
Published: December 2004

Traditional fire test methods have not required interpretation—pass/fail or a single number was recorded. New methods, such as the Cone Calorimeter or the furniture calorimeter, produce a large array of scientifically based data for each product tested. Thus, the issue of data selection and presentation becomes quite important in being able to adequately utilize such results. The new test methods were first developed and popularized by persons associated with fire‐modeling activities. Not surprisingly, the initial developments of data analysis and presentation techniques were such as to be suitable for fire scientists. The tasks of fire scientists, however, are generally different from those of the producers, specifiers of useres of various products. These latter classes of users are normally not interested in test diagnostics, portability of data, analysis of environmental effects, etc. Instead, they are intersted primarily in questions such as: Is product A better than product B and, if so, by how much? These are entirely proper questions and their answers are essential to correct specification and use of products. In this paper details of variables useful to both classes of individuals are compared and contrasted. Recommendations are made as to certain variables which are essential for the product maker/specifier/user and which could form the basis of standard product specification formats.
Fire performance studies on glass‐reinforced plastic laminates
Authors: Scudamore M. J.
Published: December 2004

Polyester, epoxy and phenolic glass‐reinforced laminates were compared in terms of their fire properties in the cone calorimeter. The presence of a gel coat on the polyester and epoxy products had some effect, mainly in the FR grades. The FR polyester with a brominated flame retardant showed a marked decrease in rate of heat release and in rate of smoke production. Aluminium hydroxide (commonly called alumina trihydrate of ATH) caused a significant delay in ignition time for the epoxy product and some reduction in rate of heat release but rate of smoke release was still relatively high. Phenolic laminates showed a long ignition time and relatively low rate of heat release (RHR). The peak RHR was further reduced by the presence of aluminium hydroxide and by changing the type of glass reinforcement. The influence of thickness was explored for a series of phenolic laminates in both cone calorimeter and the International Maritime Organization (IMO) surface flammability test. Ignition delay time was significantly affected and the cone calorimeter results showed that the shape of the RHR curve was also changed as the thickness increased. However, the heat release measurements in the IMO test were not sensitive enough to pick up the differences in this property. The type of substrate under the laminate significantly altered the burning rate but this may have been because they were not glued or mechanically fixed.
Use of zone models on simulating compartmental fires with forced ventilation
Authors: Chow W. K.
Published: December 2004

Performance of three fire zone models BR12, CCFM.VENTS and CFAST in simulating forced ventilation fires with low heat release and high ventilation rates were studied experimentally. A fire chamber of length 4.0 m, width 3.0 m height 2.8 m with adjustable ventilation rates was used. Burning tests were carried out with wood cribs and methanol to study the preflashover stage of a compartmental fire and the effect of ventilation. The mass loss rate of fuel, temperature distribution of the compartment and the air intake rate were measured. The heat release rates of the fuel were calculated from the measured mass loss rate. The smoke temperature was used as the validation parameter. A scoring system is proposed to compare the results predicted by the three models. An empirical expression for calculating the smoke temperature is assessed. Lastly, the Computational Fluid Dynamics technique is also used for comparing the simulated fire environment.
Fire performance of external wall claddings under a performance‐based building code
Authors: Wade Colleen
Published: December 2004

New Zealand Building Code Performance requirements relating to fire performance of external walls are considered and methods of evaluating the potential for vertical fire spread are discussed. Classifying external wall claddings on the basis of performance in the ‘combustibility’ test has proved overly restrictive where some external cladding materials are concerned. Performance criteria based on heat relase or ‘degree of combustibility’ are proposed and they seem to provide a better classification scheme for external wall cladding materials. Heat release test data for ten different external wall cladding materials are presented.
Mechanistic study of the combustion behaviour of polymeric materials in bench‐scale tests. I. Comparison between cone calorimeter and traditional tests
Authors: Costa L. , Caminio G. , Bertelli G. , Borsini G.
Published: December 2004

The behaviour of three typical thermoplastic polymers—polypropylene (PP), polyamide 6 (PA‐6), ABS and PP mixed with inert talc or fire retardant magnesium hydroxide or melamine—was assessed in the Cone Calorimeter and in traditional widely used tests. It is seen that the evaluation of the relative fire hazard of the materials, based on simple parameters, can be very different depending on the test used, particularly in the presence of additives. From this point of view, the Cone Calorimeter introduces an additional evaluation which might be as arbitrary as that obtained with any other test. For example, melamine, which is currently used as a fire retardant in several polymers, may be considered as a fire‐hazardous additive in PP burned in the Cone Calorimeter if only the maximum of rate of heat release is considered. The data discussed here indicate that the use of the Cone Calorimeter for simple evaluation of materials requires further investigation. It is hown that the Cone Calorimeter is a very promising tool for mechanistic studies on combustion and fire retardance, when its potential in terms of quantitative description of the whole combustion is fully used.
The generation of CO in bench‐scale fire tests and the prediction for real‐scale fires
Authors: Babrauskas Vytenis
Published: December 2004

Carbon monoxide (CO) is the single most important factor associated with deaths in fires; thus, predictions of CO developed in fires is an essential aspect of fire quantification. It is considered crucial to have correct CO prediction methods for post‐flashover fire stages, since, in the United States at least, the majority of fire deaths are associated with fires which have gone to flashover. In this paper it is shown that the yiels of CO observed in real‐scale fires are generally not related to either the chemical nature of the material being burned nor to the yield observed for the same material in bench‐scale testing. Instead, the generation of CO in real‐scale fires is determined largely according to the oxygen available for combustion, with thermal conditions of the fire plume also playing a significant role. This behavior is in sharp contrast to many other material fire properties, including yields of gases such as CO2 and HCI, which can be predicated for real‐scale fires from bench‐scale results. Finally, results from various studies completed thus far indicate how effective prediction of real‐scale CO yields may be accomplished. While bench‐scale measurements are not necessary to predict real‐scale CO, bench‐scale toxic potency measurements can be in error if the CO component in them does not reflect on the real‐scale CO yield. Thus, a method is developed whereby the bench‐scale toxic potency measurements can be computationally corected to better approximate the toxic potencies measured in real‐scale, post‐flashover room fires. These techniques will, undobtedly, be further refined as additional experimental results become available.
Metallurgical analysis of post‐crash fire evidence
Authors: Morin Charles R. , Bouldin Peter C.
Published: December 2004

This paper is based upon an actual post‐crash investigation of a high‐performance single‐eingine aircraft that crashed in mountainous terrain resulting in a post‐crah fire. A detailed metallurgical study of the fuel system separations was undertaken to identify which fittings or fuel lines had suffered mechanical damage during the initial impact sequence and which had been damaged by the post‐crash fire or in subsequent handling of the wreckage. This paper discusses some of the basic metallurgical theories used in failure analyses of aluminum alloy components involved in post‐crash fire studies. Its primary purpose is to discriminate between thermal effects of fire and mechanical overload, specifically for fuel system components. Metallurigical characterisitics cause certain specific signatures of ‘witness marks’ in mechanically induced speartions and different features in post‐crash fire separations. Discussed are frequently observed metallurgical sigantures that may be used to evaluate post‐crash, post‐fire damage. Based on the metallurgical evidence and the principles described in this paper, it was obvious that the root cause of damage to these fuel system components was either thermal exposure during the post‐crash fire or breakage after the fire during handling of the wreckage. Therefore, it was concluded that the fuel system components described herein had not been compromised during the inital impact, but rather had released fuel only after the post‐crash fire. These principles can be utilized in similar investigations but it is important to recognize the chaotic nature of seveeere crashes and the wide range of possible damage features that may result. Each investigation must, of necessaity, be based upon both basic principles and an overall assessment of the quality of the evidence as well as the need to resolve what may appear to be conflicting or questionable features of the available evidence.
The role of flame flux in opposed‐flow flame spread
Authors: Babrauskas Vytenis , Wetterlund Ingrid
Published: December 2004

The flame spread process is driven by the net heat flux to the specimen surface, including the flux from the flame itself. This flame flux is important since it comprises a major part of the driving force causing flame fluxes were obtained. The values which are reported do not appear consistent and show more deviation among materials than would be anticipated. The most common fire test used for obtaining engineering data on flame spread (ASTM E 1321) also is not formulated in terms of flame flux as a driving force. This motivated an experimental programme, whereby six materials have been studied using the flame spread geometry of the ASTM E 1321 test, but with additional instrumentation for recording heat fluxes. The flame fluxes obtained experimentally in this study show much less variation among materials than the comparable data from the literature survey.
Finite element simulation of three‐dimensional free‐surface flow problems with dynamic contact lines
Authors: Walkley M. A. , Gaskell P. H. , Jimack P. K. , Kelmanson M. A. , Summers J. L.
Published: December 2004

An arbitrary Lagrangian–Eulerian (ALE) finite element method is described for the solution of three‐dimensional free‐surface flow problems. The focus of this work is on extending the algorithm to include a dynamic contact line model allowing the fluid free surface, in the steady case, to form a prespecified static contact angle with a solid boundary and, in the transient case, to move along the solid boundary. This widens the applicability of the algorithm to important industrial applications such as forced spreading of fluids and gravity‐driven flow on inclined surfaces. Copyright © 2004 John Wiley & Sons, Ltd.