bluuebunny/crossref_metadata_2025 huggingface dataset:
Conversion of fuels containing nitrogen to oxides of nitrogen in hydrogen and methane flames
Authors: Woolley W. D. , Fardell P. J. , Atkinson A. B. , Verrall A. P.
Published: May 2005

Nitrogen‐containing compounds such as hydrogen cyanide, acetonitrile, acrylonitrile, pyridine, benzonitrile, ammonia and methylamine, which are typical of the products likely to be encountered during the decomposition of nitrogen‐containing polymers in fires, have been introduced into hydrogen and methane flames burning in oxygen‐argon atmospheres. There is a complete conversion of fuel nitrogen in all cases to oxides of nitrogen and molecular nitrogen. The relative conversion to oxides of nitrogen (as NOx/N2) increases as the injection rate of nitrogen‐containing fuels is decreased. The relative yields of oxides of nitrogen tend to be similar with methane and hydrogen premixed flames and markedly greater than observed with hydrogen diffusion flame. In all cases the yield of oxides of nitrogen‐containing products such as hydrogen cyanide can also present a toxic risk during the burning of nitrogen‐containing polymers, particularly when high temperature are involved. The combustion of these products in flame zones cannot be assumed to alleviate the additional toxic risk because of their conversion to oxides of nitrogen.
Ignition and flash‐fire studies of cellulosic materials
Authors: Hilado Carlos J. , Murphy Regina M.
Published: May 2005

Various celloulosic materials were evaluated for ignitability and flash‐fire propensity, using screening test methods developed at the University of San Francisco. Time to ignition, using radiation from a high‐temperature radiant source without a pilot flame, appeared to be primarily a function of heat flux and material density, rather than of type of wood or celloulosic board. At heat flux levels from 5.8 to 10.5 W cm−2, time to ignition was shortest for cellulose fiberboard with a density of 0.2225 g ml−1, followed by western red cedar at 0.314 g ml−1, eastern white pine at 0.348 g ml−1, southern yellow pine at 0.422 g ml−1, Douglas fir at 0.565 g ml −1, and longest for hardboard at 0.878 g ml−1. For the cotton and rayon woven‐pile upholstery fabrics, time to ignition appeared to increase with increasing fabric weight.

For Cellulose insulation treated with boron‐containing additives, flash‐fire magnitude decreased with increasing additive content. Flash‐fire magnitude decreased more that could be accounted for by decreasing weight loss alone, indication reduction in the combustibility of the volatiles produced. Reduction in flash‐fire propensity of cotton bating by treatment with boron‐containing additives was also observed.
A procedure for assessing the change in flame spread characteristics of paints when subjected to washing
Authors: Pettitt M. , Routley A. F.
Published: May 2005

A Collaborative Programme of work was carried out by two laboratories to asscess a procedure for identifying paint systems which possess poor ‘in service’ lives by virtue of being repeatedly washed. The small scale surface spread of flame apparatus as described in BS 476 part 7 was used to measure any change in the surface spread of flame characteristic of eight coating system, applied to two substrates, as a result of washing the coated surfaces. The results indicate that both laboratories ranked the paints in the same order and the reproducibility of the proposed washing procedure was good. The most consistent results were obtained when the coating systems were applied to standard hardboard. It is suggested that flame retardant coating system having poor resistance to washing would be identified if a limit of changes of average spread of flame were set at 75 mm. This investigation was carried out in support of the activities of BSI committee PVC/12, Fire Retardant Paints.
Combustion characteristics of UPVC pipe grade materials
Authors: Brown S. K. , Martin K. G.
Published: May 2005

Samples of current Australian production of unplasticized polyvinyl chloride pipe and fitting materials have been examined in relation to combustion characteristics. Small scale laboratory assessment of piloted radiant ignition flame propagation and smoke generation have been investigated. Where necessary, improvements to methods of test or analysis of data have been developed and factors that influence results have been investigated. Piloted radiant ignititon and smoke production under flaming conditions are shfown to be the important combustion characteristics of UPVC materials for improvement.
The importance of cyanide and organic nitriles in fire fatalities
Authors: Anderson R. A. , Thomson I. , Harland W. A.
Published: May 2005

A 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 1−1 blood. 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 demonstrated.
Second moment reliability analysis of fire exposed wood joist floor assemblies
Authors: Woeste F. E. , Schaffer E. L.
Published: May 2005

A reliability analysis using second moment approximations is conducted on a fire exposed unprotected wood joist floor. A methodology is illustrated by which the probability of structural failure of a wooden floor assembly can be evaluated. This probability along with the probabilities of failure of other system components can be used in a system analysis which appears to be a vital approach to a more realistic analysis of building fire safety. The use of reliability analysis to compare the relative fire safety of different floor components is demonstrated. A procedure for introducing new components into the marked based on the concept of an equal safety index as calculated for a component with a proven in‐service record is discussed.
Protective clothing: Evaluation of zirpro wool and other fabrics
Authors: Benisek L. , Edmondson G. K. , Phillips W. A.
Published: May 2005

Protective clothing against head and flames should be evaluated not only for flame retardance but also for protection against various heat exposure from convection (flames), conduction (molten metal splashes) and radiation sources, depending on the end use, to ensure a realistic assessment of the potential protection offered and required. Evaluations of various flame‐retardant fabrics to different heat exposures showed that the fibre and the flame retardant finish should preferably form a well developed char on exposure to heat, without softening and melting. The flame retardant should act in the solid phase and the fibre should be of low thermal conductivity. For protection against convective heat (flames), a woven Zirpro wool fabric of high density over a bulky knitted Zirpro wool underwear fabric offered a significantly better protection than a single layer of a woven or knitted fabric or a double layer of a woven fabric of the same total weight. The optional multi‐layer fabric approach could also decrease overall garment weight and improve wearers' comfort without adverse effect on the protection offered. Of the FR fabrics evaluated, Zirpro wool fabric assemblies showed the longest time to reach pain (first degree burn) and blister (second degree burn) thresholds, as well as the longest pain alarm time–the time available to the wearer to withdraw from the flame heat source before serious injuries occur. Zirpro wool fabric assemblies had one of the lowest residual heat transfers after al limited flame exposure to the pain threshold while some other fibres, e.g. aramid and novoloid, transferred significant residual heat, possibly causing second degree burns. For protection against conduction, such as from molten aluminium splashes, the fabric should have a smooth surface, high density and thickness, besides the other previously mentioned, basic requirements. Zirpro wool fabrics offered a significantly better protection in this case than aramid, FR cotton, glass fibre, asbestos, and other FR fibres. Aluminized fabrics are essential for adequate protection against radiant heat and the aluminization technique affects heat transfer significantly. A low density base fabric made from a fibre of low thermal conductivity, such as Zirpro wool, reduces heat transfer in this case.
The continuing problem of serious burns involving the ignition of clothing, particularly nightwear
Authors: Warne C. A.
Published: May 2005

Despite a decrease in the UK, in the number of fatal accidents resulting from the ignition of clothing, there are still some 115 fatalities and many serious accidents each year. The research described in this paper identified groups of such accidents which involved nightwear garments and which might also be amenable to further prevention action. Detailed analysis of 64 cases suggested that further specific preventive action could have some impact on burns to the elderly involving nightdresses and burns to all age groups which involved pyjamas or dressing‐gowns.
Fire performance of glass reinforced polyesters
Authors: Parvin K.
Published: May 2005

Glass reinforced polyesters (GRP), or the resins used, have to pass a wide variety of tests which vary considerably from country to country and from industry to industry. Some of these tests are carried out on a scale outside the capabilities of most laboratories and the results leave much to be desired in the matter of reproducibility. All these factors lead to problems for the formulator of fire‐retardant unsaturated polyester resins.
Legislation in the United Kingdom relating to plastics, polymers and textiles
Authors: Christian S. D.
Published: May 2005

This paper deals with legislation enacted in the United Kingdom for the control of the hazard form fire in buildings of public resort such as hotels, boarding houses, factories, offices and shops as well as domestic dwellings. It gives background to why the various Acts were deemed necessary, why subsequent Regulations under the Acts were introduced, an impression on the effect their enforcement has had and an introduction into what is envisaged for the future. The legislation is not the product of any one Government department nor is it enforced by any single agency. Much of it is enforced by local authority fire brigade fire prevention departments and other sections by local authority Building Control Officers. It is the view of the author that more controls are required by way of Regulations and that certain of the Regulations at present in force are in need of revision. Included in the paper are tables of the latest statistics available (1976) together with other data, previously unpublished, which in the author's opinion justify his claim that more controls are needed. In the final part of the paper the author recommends most strongly that the gap in the present British Standard fire tests produced by the lack of an effective means of evaluating the smoke‐producing qualities and the toxicity of the produced by the lack of an effective means of evaluating the smoke‐producing qualities and the toxicity of the products of combustion of different materials should be urgently studied with an amended priority.
An application of the self‐ignition method of polymers: Anti‐smoke additive induced glowing effect in the combustion of poly(vinylchloride)
Authors: Descamps J. M. , Delfosse L. , Lucquin M.
Published: May 2005

The effect of anti‐smoke additives in poly(vinylchloride) (PVC) has been studied using self‐ignition methods. The self‐ignition reaction was followed thermally, visually and by gas—liquid chromatography of the gaseous phase around the sample. Particular emphasis was palced on the determination of the CO, CO2 and aromatic species. It is shown that ferrocence, among similar additives, considerably modifies the self‐ignition behaviour of PVC by inducing glowing phenomena of various kinds. In some cases this incandescence can lead to self‐ignition. From the analysis of carbon oxids and aromatic species as a function of time and temperature, it is possible to deduce that the anti‐smoke reaction is associated, at least partially, with reactions which lead to incandescence. These reactions transform the carbon into carbon oxides instead of producing, in the gaseous phase, molecules which on further condensation lead to aromatic species at the origin of the soot. In short, the anit‐smoke reaction appears to proceed mainly through a competing mechanism.
Skin damage due to heat transfer by conduction
Authors: Stoll A. M. , Chianta M. A. , Piergallini J. R.
Published: May 2005

This study provides basic data with respect to pain and burns produced on short‐term contact of bare skin with heated substances. The data may also be used to determine the thermal properties and thicknesses of fabrics or coatings required to prevent injury in such contacts. The maximum temperature any material might attain without causing injury on contact with bare skin was determined from measurements of pain threshold during contact with heated materials representing a wide spectrum of thermal properties form good conductors to good insulators. Pain threshold times were converted to blister times and the latter extrapolated to predict those temperatures at which blistering would result form ‘instantaneous’ (0.3 s) contact. The predicted temperatures were verified experimentally in contacts with four different materials. From these data, charts and equations were derived by which the maximum permissible temperature for safe contact could be determined for any material solely form a knowledge of its thermal conductivity, density and specific heat. Additionally, equations for transient heat flow in two‐layer systems yield the thickness of coatings, fabrics or other thermal barriers of known properties which would be required to protect the skin form pain or burn on contact with materials at excessive temperatures.
Biological end‐points for the assessment of the toxicity of the products of combustion of materials
Authors: Farrar D. G. , Galster W. A.
Published: May 2005

The toxicological end‐points used in a method for the assessment of the toxicity of combustion products are described. The evaluation considers three areas of toxicological interaction: incapacitation, death, and post‐exposure involvement. The model of incapacitation described is the leg‐flexion avoidance response of the rat. Additional end‐points to assist in the determination of the causality of the observed toxicity are included. The effects of the combustion products of Douglas fir, a phenolic foam, a urea formaldehyde foam and a flexible polyurethane foam on these endpoint are described. The wide range of types of potential toxicities resulting form exposure of animals to the combustion products of materials is discussed. Additionally discussed are the relative merits of the leg‐flexion avoidance response as a model of incapacitation. Conclusions as to the important components of a first‐tier toxicological evaluation of combustion products are drawn.
Flammability testing in Europe
Authors: Walker A. G.
Published: May 2005

This paper outlines the current situation of fire testing in Europe under the headings of combustibility, ignitability, flame spread, heat release, smoke tests and toxicity.
Intumescent coatings and their uses
Authors: Rhys J. A.
Published: May 2005

Thin coats of flame‐retardant paints are unable to protect flammable substrates as there is not sufficient flame retardant in the thin coat to protect the substrate. Intumescent coatings foam and bubble when subjected to high temperatures and create multicellular cushions which prevent (a) heat from penetrating into the substrate and (b) flames from spreading along the surface. This paper concentrates on paints and varnishes, but also considers protective coatings for structural steel, smoke proof and wall piercings.
An evaluation of heat release criteria in reaction‐to‐fire tests
Authors: Vandevelde P.
Published: May 2005

A theoretical approach is developed for evaluating quantitatively the heat evolved during a reaction‐to‐fire test. This involves determining the transfer function from two head balance equations, one concerning the walls and the other the air in the test box. A comparison between this theoretical approach and the empirical ‘area under the curve’ method has been made for 34 tests on electrical cables. It is shown that the empirical method is unacceptable.
Anomalous behaviour in certain versions of the critical oxygen index test
Authors: Wharton R. K.
Published: May 2005

Measured Critical Oxygen Index values at 40°C for Opal polymethylmethacrylate (Perspex) sheet have been found to be remarkably dependent on the gas velocity within the column of the Hot Flammability Test Apparatus. Investigation of the atmosphere present in the column has indicated that the effect is almost solely attributable to varying quantities of ambient air entering the column as the flow rate is altered. A modification to the apparatus is proposed that successfully prevents this entrainment of air at normal testing flow rates.
A computational study of physical and chemical inhibition in a perfectly stirred reactor
Authors: Brown Nancy J. , Schefer Robert W.
Published: May 2005

This paper reports a set of modeling studies that were undertaken to acquire a more detailed knowledge of combustion inhibition mechanisms. Mixtures of H2/O2/Ar reacting in the idealized perfectly stirred reactor were investigated. Three H2/O2 kinetic mechanisms were considered, differing from one another by the number of HO2 reactions included. Two physical inhibitors, Ar and N2, and one chemical inhibitor, HBr, were investigated. Additional parameters considered were pressure, equivalence ratio, inhibitor concentration and rate coefficient variation. The most effective inhibitor was HBr which acted chemically and caused substantial reduction in radical concentrations in the mixtures considered. The molecules Ar and N2 acted as physical diluents with N2, the more effective of the two due to its larger heat capacity.
Hydraulic fluids: An approach to high pressure spray flammability testing based on measurement of heat output
Authors: Roberts A. F. , Brookes F. R.
Published: May 2005

One of the main hazards associated with the use of hydraulic fluids is the accidental release of hydraulic fluid near to a source of ignition. Several tests simulating this hazard have been developed but, in the opinion of the authors, none fulfils all the scriterla required of a flammability test. A new form of test has been developed. A test chamber is ventilated by a smooth flow of air; the hydraulic fluid under test is sprayed into the test chamber and ignited. The temperature rise in the gases leaving the stack and the radiation from the flame are measured at a specified time and from these measurements the heat output of the flame is estimated. Different fluids are then compared on the basis of their heat output values and data are presented in the paper for a variety of fluids.
The influence of sample dimension on the critical oxygen index of thin polypropylene films
Authors: McIlhagger R. , Hill B. J.
Published: May 2005

This investigation examines the influence of sample dimensions on the Critical Oxygen Index, as determined on a Stanton Redcoft Hot Flammability Test Apparatus instrument. The materials used were polypropylene films in a range of thicknesses from 40 μm up to 300 μm and polymethylmethacrylate of 1600 μm thickness. Both the Critical Oxygen Index and the rate of spared of burn in the samples were determined. It is concluded that, for polypropylene, the sample dimensions were important in determining the Critical Oxygen Index and the rate of spread of burn and, further, that the ratio of the volume of material burned in unit time to the volume flow of oxygen in the same time remains constant, the value of the constant being 2.5 × 10 −4. For polymethlmethacrylate, in confirmation of the work of Fenimore and Jones, the sample dimensions were unimportant when investigating the Critical Oxygen Index, although the rate of burn by volume showed a significant increase with sample width. The volume ratio showed a corresponding increase.
An investigation of the variation of oxygen index of materials with changes in pressure
Authors: Routley A. F. , Ludlam N. P.
Published: May 2005

An apparatus has been designed and a procedure adopted for studing the oxygen index of materials over a range of pressures. It has been found that the oxygen index falls with increase in pressure so that materials become more flammable, the effect being more marked with the less flammable materials. An empirical method has been devised for predicting the oxygen index at varying pressures.
Modeling of NBS mattress tests with the harvard mark V fire simulation
Authors: Rockett John A.
Published: May 2005

NBS burned eleven mattresses made up with bedding in two different rooms, typical of a residential bedroom and a nursing home patient room, respectively. Seven of the mattresses flamed and burned vigorously, the other four were of a construction or so heavily flame‐inhibited that they only smoldered. The burning behavior of the seven that flamed was modeled with the Harvard Mark V fire simulation. The experimental burn behavior for tests conducted in one room was well reproduced using only total weight of combustible, surface area and heat of combustion. Smoke production values were found to have little effect on the predicted behavior except for the smoke production itself. Fires in a second room, whose ventilation was intentionally restricted by the configuration of the adjoining space, could not be as well reproduced by the present, single‐room fire model. During this study several changes were made to the simulation. The most significant change was the inclusion of mixing of the hot exiting fire gases with the cold incoming air. As a part of this, the inter‐layer radiation exchange was reformulated to include the effect of smoke contamination of the lower layer. The reformulation of the radiation model has a marked effect on the predicted upper layer gas temperatures, generally improving the quality of the simulation.
Effect of fire‐retardant additives on the time‐resolved processes of polymer combustion
Authors: Kishore K. , Mohandas K.
Published: May 2005

The effect of various inorganic and organic additives on various time‐resolved processes (e.g. degradation, ignition, burning rate and quenching) in the combustion of polystyrene has been examined. They are found to impart favourable as well as unfavourable effects on various combustion steps, the important implication being the selection of fire‐retardant additives for the specific hazards encountered in end use.
The thermo‐oxidative degradation of PTFE in the NIST cup furnace toxicity test
Authors: Metcalfe E. , Harman A. R. , Patel M. K.
Published: May 2005

Long‐lived end‐chain peroxy radicals have been detected during the thermo‐oxidative degradation of PTFE. These radicals are associated with the fine particulate, which is the established cause of the ultra‐high toxic potency of PTFE produced under the conditions employed. The particulate has been further characterized by a vareity of thermo‐analytical methods. Fluid‐flow modelling analysis has been used to simulate the recirculatory behaviour, characteristic of the NIST cup furnace toxicity test, which may effect the continuous regeneration of the toxicity.
Note: Correlation of flash points
Authors: Satyanarayana K. , Kakati M. C.
Published: May 2005

A general correlation has been obtained for prediction of closed‐cup flash points of organic compounds from their normal boiling points and specific gravity. Predicted flash points are within an average deviation of 8.301 of the reported values.
Fire performance of gusset connections in glue‐laminated timber
Authors: Buchanan Andrew H. , King Andrew B.
Published: May 2005

This paper describes a comprehensive experimental investigation of the fire performance of nailed gusset connections between large glue‐laminated timber members. Both plywood and steel gusset plates were investigated with a range of loaded and unloaded test methods. The principal conclusions are that unprotected gussets have poor fire performance, but that a layer of solid wood or gypsum plasterboard will provide at least one hour of fire protection to typical joints.
Piloted ignition of wood: A review
Authors: Janssens Marc
Published: May 2005

The physical phenomenon of piloted ignition of a material is described. A number of mathematical models of this phenomenon are presented in order of decreasing complexity. The most sophisticated models include gas‐phase phenomena. Simple models neglect all chemical effects and are purely thermal. The most commonly used criteria for piloted ignition are discussed. Correlations used in piloted ignition studies from the past 40–50 years are summarized. Many investigators have been successful in correlating piloted ignition data of wood using a simplified thermal model in combination with a critical surface temperature criterion. Emphasis of this review is therefore on this approach. The paper concludes with a detailed analysis of various factors affecting piloted ignition of wood. Some of the factors are related to the experimental conditions, others are associated with the characteristics of the material.
Effect of condensed‐phase and gas‐phase flame retardants on the ignition behaviour of cotton fabric
Authors: Khattab M. A. , Kandil S. H. , Gad A. M. , El‐Latif M. , Morsi S. E.
Published: May 2005

The purpose of this study is to evaluate the effect of some well‐known flame retardants on the ignition behaviour of cotton fabric. Two types of flame retardants acting in different phases (e.g. condensed phase and gas phase) were used. At low add‐on of the retardant acting in the condensed phase the ignition behaviour of the cotton is different from that treated with retardant acting in the gas phase. The condensed‐phase retardant caused cotton to burn more rapidly than untreated fabrics. This was attributed to the fact that small add‐on of the retardant makes the fuel for the flame available at a lower temperature. However, in the presence of sufficient amounts of retardant, the decomposition of cellulose becomes more directed towards the dehydration mechanism and thus the concentration of the flammable gases is insufficient to reach the flammability limits required. When gas‐phase flame retardants were used, a linear dependency of ignition time on the concentration of additive was found. This is explained in terms of the dilution effect of this retardant on the fuel produced from the decomposing fabric.
Analysis and interpretation of the plumbing materials file of the NYS combustion toxicity data bank
Authors: Wallace Deborah
Published: May 2005

New York State's Building and Fire Prevention Code includes a requirement that combustible materials used in electrical, plumbing and finishing systems be tested by the University of Pittsburgh protocol and that particular data from that testing be reported on standard forms to the Office of Fire Prevention and Control. The plumbing file in this data bank contains data on 41 products, excluding minor usages. In this paper, these data plus the data on Douglas fir are reported and analyzed. LC50 was found to have significant correlations with indices of thermal instability, of rate of mass loss, and of corrosive irritants. The most parsimonious model developed with stepwise regression correlated LC50 with three factors: %wt loss per degree of temperature rise, temperature at the beginning of rapid weight loss‐temperature at which 1% of the sample weight was lost, and temperature at the end of rapid weight loss‐temperature at which 1% of the sample weight was lost. LC50 was weakly correlated with maximum CO concentration and in the ‘wrong’ direction (high CO concentrations were associated with low toxicity). Log LC50 was significantly correlated with Log COmax, but also in the ‘wrong’ direction. LC50 was correlated with minimum oxygen concentration with a small R‐squared and also in the ‘wrong’ direction. The question of the relevance of these test results to smoke exposures in real fires is discussed.
Smoke results from a set of over 100 carpets in the NBS smoke chamber: Statistical analysis and investigation of affecting factors
Authors: Hirschler Marcelo M.
Published: May 2005

A large set of carpets was tested vertically in the NBS smoke chamber (ASTM E662), in two ways: along the length and along the width of their grain pattern. The set comprised 104 carpets. The results were analyzed in order to investigate the potential effect of carpet grain direction on the results obtained. It was shown that there is no statistically significant difference between the orientation of the carpet (width or length). Moreover, the degree of agreement was the same whatever the result of the test. Several other variables were found to have an effect. The most important of these is the sample weight, but others are carpet construction, yarn type and backing material. It was found that the testing mode (flaming or non‐flaming) did not appear to affect the results of this set of samples in a statistically significant way.
Hybrid fibres in fire protection
Authors: Heidari Shahram , Kallonen Raija
Published: May 2005

A series of cellulose–polysilicic acid hybrid fibres with 15–35% silica contents were spun and their flammabilities were assessed by the LOI oxygen index test. Also, the rate of heat release and toxicities of fumes evolved during the combustion process for hybrid fibre with 33% SiO2 loading was obtained using the cone calorimeter and FT‐IR techniques. The low flammability and toxicity indices indicate that this hybrid fibre can be used as a flame‐retardant fibre.
The effects of specimen edge conditions on heat release rate
Authors: Babrauskas Vytenis , Twilley William H. , Parker William J.
Published: May 2005

When bench‐scale specimens are tested for heat release rate, it is generally of interest that the behavior of the specimen simulate, as much as is possible, that of a real‐scale product performing in a real fire. A number of issues have been raised recently by workers trying to understand the optimal conditions of specimen preparation and mounting. In the present study a large number of materials were explored in the Cone Calorimeter to determine the effect of edge conditions and edge frames. It was found that by the use of an insulated edge frame, heat release rate values can be obtained which are slightly closer to expected true values. The testing procedure, however, is significantly more complicated. This makes the insulated edge frame useful for collecting specialized data for fire modeling, but not for conducting routine reaction‐to‐fire tests. For routine testing use, it is recommended: (1) that no edge frame needs to be used unless the test specimen presents special difficulties, such as due to intumescence; (2) that in those cases where the use of the steel edge frame is found necessary, the results should be reported on the basis of an effective exposure area of 0.0081 m2. When reported on such a basis, the heat release rate results do not show a systematic bias, compared to results with no edge frame.
Flame height behavior from multi‐fire sources
Authors: Sugawa Osami , Takahashi Wataru
Published: May 2005

The flame height behavior of merged or inclined flames from two rectangular fire sources in a parallel configuration and from three and four circular pools of 120 mm diameter in a symmetrical configuration were studied experimentally. A rectangular gas diffusion burner, 20 mm × 400 mm or 20 mm × 800 mm was used as line fire sources. Propane gas gave 9.5–57 kW per meter for each burner. Hexane was utilized for the flame merging test using circular pool fires. The height of the flame tip when merged or inclined due to interaction of the flames and|or convective flow was estimated from picture analysis of 300 successive frames of video‐recorded data. The flame extension behavior was expressed in dimensionless form as L/Lm = (fs)2/5 for square pool fires and L/Lm = (f1)2/3 for rectangular fires. The correction factors of fs and f1 are fs = (nD2 + S2) / n(D2 + S2) and f1 = (2DW + S2) / 2(DW + S2), respectively. When a rectangular or a circular fire source approaches the wall, the same correlation on flame extension behavior was obtained and simulated successfully considering an imaginary fire source inside a wall.
Combustion behaviour of fabric and polyurethane flexible foam mock‐up combinations under Cone Calorimetry test conditions
Authors: Vanspeybroeck R. , Van Hees P. , Vandevelde P.
Published: May 2005

The relative contributions of fabric and foam on important fire hazard parameters as measured in the cone calorimeter were determined for various mock‐up combinations. Three commercial types of high‐resilience PU flexible slabstock foams, representing a wide range of combustion performance, were combined with three different fabrics: polyester, polypropylene and combustion‐modified cotton. Total heat release of the combinations correspond well with the value calculated from the individual components and is determined by the density and effective heat of combustion of the components, and the foam/fabric weight ratio. The foams show a smaller variation in effective heat of combustion than the fabrics. Covering of PU flexible foams with a fabric results in general in a delay of ignition and peak rate of heat release. Performance of the mock‐ups is mainly determined by the fabric but is also influenced by the quality of the foam.
Physical properties of a sprinkler water spray
Authors: Chow W. K. , Shek L. C.
Published: May 2005

This paper reports an experimental study on the physical properties of a sprinkler water spray. The mass flux density, shape of spray pattern, size distribution and velocity of water droplets discharged from two types of 15 mm orifice sprinkler heads were measured. Three operating flow conditions of the sprinkler system, including one specified for the Ordinary Hazard class under the LPC rules for sprinkler design, were set. The sprinkler head was installed above finished floor levels of either 2 m or 2.2 m. The median droplet size was found to be related to the water pressure and the orifice diameter of the sprinkler head as proposed by Dundas. The droplet size distribution function can be fitted by a Rosin–Rammler function.
Pulp capping with synthetic hydroxyapatite in human premolars
Authors: Frank R. M. , Wiedemann P. , Hemmerle J. , Freymann M.
Published: May 2005

Classically, calcium hydroxide is used as a pulp capping agent in humans to form a dentinal bridge over vital dental pulp tissue. The aim of the present study was to determine whether synthetic hydroxyapatite could be used as a substitute. For this purpose, pulp capping with microsized hydroxyapatite (mean size = 38 nm ± 15 nm) was done under lacal anesthesia in 12 normal premolars, to be extracted for orthodontic purposes form 12 different young patients, having given their informed consent. Clinically, the healing was uneventful in all patients, having given their informed consent. Clinically, the healing was uneventful in all patients. Half of the teeth were extracted at 3 months and the other half at 6 months. The pulps were studied under light microscopy and under scanning and transmission electron microscopy using nondecalcified sections. In all cases, a continuous, well‐calcified bridge was observed and no inflammatory cells were present in the residual pulp. In some cases denticles containing some synthetic hydroxyapatite crystals were found in the radicular pulp. The calcified bridge was made up by osteodentine and near the pulp tubular dentine with a layer of predentine and odontoblasts were noted. Odontoblastic processes were lacated in deninal tubules and the intertubular dentine showed interwoven calcified collagen fibrils and hydroxyapatite crystals with a mean length of 0.1 μm along their c axis.
Fibroblast shape conformation to surface micromorphology
Authors: Meyle J. , von Recum A. F. , Gibbesch B. , Hüttemann W. , Schlagenhauf U. , Schulte W.
Published: May 2005

Fibroblasts in culture and in vitro have been shown to interact with certain surface morphological phenomena. It was the aim of the present study to determine cellular morphological interactions with surface grooves of subcellular dimensions. The silicon oxide layer of a wafer was photoetched, which resulted in a regular micromorphology with linear rectangular shaped microbars and microgrooves 1, 1.5, and 2 μm in diameter and distance from each other. Human fibroblasts were seeded on the sterile specimen and incubated for 48 h. Fluorescence microscopy of the plates revealed that all the cells were aligned parallel to the etched grooves on the test specimen, whereas on the controls the cells were randomly orientated. It could be demonstrated by scanning electron microscopy that single cels were flattened over the surface and conformed to the silicon microgrooves. This indicates that fibroblasts are orienting during adhesion and conform to the surface microtexture to gain a maximum contact area on the presented surface.
The effect of the addition of methylene blue on the fatigue strength of simplex P bone–cement
Authors: Davies Jeffrey P. , Harris William H.
Published: May 2005

To aid in cement removal during revision arthroplasty, it has been proposed to add methylene blue to bone cement to provide contrast between the cement and bone. However, it is essential that the fatigue strength of the cement not be reduced by the addition of the methylene blue. The effect of adding 1 mL of an aqueous 1% solution of methylene blue to one pack of Simplex P prepared in the standard fashion (uncentrifuged) was studied. We also measured the fatigue properties of centrifuged Simplex P with three different methylene blue preparations. We studied adding 1 mL of an aqueous 1% solution of methylene blue, 0.5 g of methylene blue powder, and 0.1 mL of a 10% solution of methylene blue per pack of Simplex P bone cement. Adding 1 mL of a 1% methylene blue solution to 40 g of Simplex P without centrifuging the cement after mixing produced a cement with a mean fatigue life comparable to the uncentrifuged Simplex P without the methylene blue. However, the fatigue data scatter was higher for the uncentrifuged methylene blue preparation. The optimum methylene blue impregnated cement preparation was produced by adding 1 mL of a 1% methylene blue solution to 40 g of Simplex P powder, mixing with chilled monomer, and centrifuging for 60 s. Sterile 1 mL vials of 1% methylene blue solution are available in the operating room. Thus the experienced surgeon can use a cement containing color to facilitate distinguishing cement from bone in cases needing revisions without weakening the cement.
Polypropylene IUCD retrieval fibers: Surface morphology, material properties, microbial attachment, and migration
Authors: Coughlin Robert W. , Vietn Robert F. , Dibenedetto Anthony T.
Published: May 2005

Highly drawn and oriented polypropylene fibers used for the retrieval thread of the Cu‐7 intrauterine contraceptive device (IUCD) are compared as to surface morphology and crystallinity with polypropylene fibers prepared under different conditions. A series of experiments also demonstrates the colonization of the surface of polyolefin fibers by pathogenic bacteria that are often found in the human vagina. Moreover, it is demonstrated that the retrieval threads appear to encourage pathogenic bacteria to migrate across the surface of agar. The results also indicate that control of drawing and annealing can avoid the surface fibrillation and tendency to fail by separation into a bundle of multifilaments that are observed with the IUCD retrieval threads.
A silver‐sulfadiazine‐impregnated synthetic wound dressing composed of poly‐l‐leucine spongy matrix: An evaluation of clinical cases
Authors: Kuroyanagi Yoshimitsu , Kim Eikichi , Kenmochi Makoto , Ui Kenji , Kageyama Hiromi , Nakamura Motonobu , Takeda Akira , Shioya Nobuyuki
Published: May 2005

The management of severe burns requires the suppression of bacterial growth, particularly when eschar and damaged tissue are present. For such cases, silver sulfadiazine (AgSD) cream has been traditionally applied. This antibacterial cream, however, cannot be used in conjunction with a temporary wound dressing that is needed to promote healing. The authors developed a synthetic wound dressing with drug deliver capability for clinical use by impregnating a poly‐‐ spongy matrix with AgSD, which is released in a controlled, sustained fashion. In general, the dressing adhered firmly to the wound in the case of superficial second‐degree burns, and during the healing process it separated spontaneously from the re‐epithelialized surface. In the management of deep second‐degree burns where eschar and damaged tissue were present, the dressing had to be changed at intervals of 3 to 5 days until it adhered firmly to the wound. Once the dressing had firmly attached to the wound, it was left in place until it separated spontaneously from the re‐epithelialized surface. Dressing changes were fewer than with other treatments and the pain was effectively reduced. Cleansed wounds were effectively protected from bacterial contamination. Of 52 cases treated with this wound dressing, 93% (14/15) of superficial second‐degree burns, 75% (3/4) of deep second‐degree burns, 85% (6/7) of superficial and deep second‐degree burns, and 75% (12/16) of split‐thickness skin donor sites were evaluated as achieving good or excellent results.
Self‐reported signs and symptoms in breast implant patients with novel antibodies to silicone surface associated antigens [anti‐SSAA(x)]
Authors: Kossovsky Nir , Gornbein Jeffrey A. , Zeidler Michelle , Stassi John , Chun Grace , Papasian Nora , Nguyen Rachel , Ly Kahn , Rajguru Samir
Published: May 2005

In research animals, the immune adjuvant activity of silicone in eliciting antibodies to associated protein antigens is now well established. In humans, the immune adjuvant activity of silicone remains controversial. Clusters of data from various research groups are beginning to define the boundary conditions for future large epidemiological studies. In that spirit, this manuscript reports pilot clinical data from a serological study conducted 3 years ago and reported previously in this journal. Sera from a self‐selected symptomatic population of patients with breast implants were assayed for elevated concentrations of antibodies showing binding avidity to silicone surface associated antigens [anti‐SSAA(x)]. In that study of 249 patients, two distinct statistically significant subgroups were identified on the basis of the serological assay alone: patients without any elevated anti‐SSAA(x) (negative) and patients with elevated anti‐SSAA(x) (positive) (p < 0.001). In this study, a clinical survey returned by 226 of those patients was correlated with the previously acquired serological findings. The 11 most common clinical complaints reported by the 199 anti‐SSAA(x) negative patients and by the 27 anti‐SSAA(x) positive were compared and their frequencies analyzed. The 199 anti‐SSAA(x) negative patients, as a group, showed a lower frequency of a variety of signs and symptoms compared to the 27 anti‐SSAA(x) positive patients. Statistically significant differences were seen in three of the symptoms: fever, foot pain, and sleep disturbance (p < 0.05). In addition, the syndrome of fever in the absence of local chest pain was a significantly associated with anti‐SSAA(x) positivity (p < 0.001). © 1995 John Wiley & Sons, Inc.
Effects of precoating surface treatments on fatigue of Ti‐6Al‐4V
Authors: Eberhardt Alan W. , Kim Byeong S. , Rigney E. Douglas , Kutner Gerald L. , Harte Charles R.
Published: May 2005

Grit blasting is a common procedure of roughening surfaces to promote physical attachment of porous coatings, but it has been shown to reduce fatigue strength. Shot peening is known to increase fatigue strength by inducing compressive surface stresses; however, it is not known how subsequent grit blasting affects these benefits. This study examines the endurance limits, Se, of ELI grade Ti‐6A1‐4V specimens under rotating cyclic bending, including polished (control); belted and beaded; belted, beaded, and grit blasted; and belted, beaded, shot peened, and grit blasted. Belting and beading resulted in a slight increase in Se; grit blasting caused a 15% reduction in Se from polished. Fifty percent of this reduction was recovered when shot peening preceded grit blasting, suggesting that residual compressive surface stresses, induced by peening, were not eliminated by the blast process. Roughness averages and RMS values did not correlate with Se trends. SEM results showed classical fatigue fractures, consistent with surface crack initiation. © 1995 John Wiley & Sons, Inc.
Biological materials fixed with an epoxy compound: Comparison of the effects with or without ionically bound heparin
Authors: Sung Hsing‐Wen , Shih Jeng‐Shiuan
Published: May 2005

Biological materials have been used as prosthetic devices such as heart valves, vascular grafts, and pericardial patches. These biological materials have to be fixed with crosslinking reagents and sterilized subsequently before they can be implanted in humans. Recently, a new crosslinking reagent, epoxy compound, has been used to fix bioprostheses. In this fixation technique, heparin may be ionically bound on the tissue surface. It has been shown that the amount of heparin bound to the tissue surface is proportional to the quantity of protamine impregnated in the biological tissues. However, it is not known if the impregnation of protamine will affect the crosslinking density of the biological tissues. This study was designed to compare the crosslinking densities of the epoxy compound fixed biological tissues with or without heparinization. Fresh porcine aortic valves procured from a slaughter house were first impregnated in various concentrations of protamine sulfate (0, 0.5, 1.0, or 1.5%) for about 30 min. The porcine aortic valves were then crosslinked in a 4% epoxy compound solution (Denacol® EX‐313). The porcine samples were taken out at various elapsed fixation periods: 18, 25, 48, 72, 96, and 120 h. Finally, the crosslinked porcine aortic valves were heparinized in a 0.5% sodium heparin solution for about 1 h. The crosslinking densities of the porcine leaflet and the aortic wall of each sample were determined by measuring their shrinkage temperatures. It was revealed that the impregnation of various concentrations of protamine did not seem to significantly alter the shrinkage temperatures of the porcine leaflet and the aortic wall throughout the entire fixation process (p > 0.05). This indicated that the impregnation of protamine did not significantly change the crosslinking density of the biological tissues. However, it was found that protamine tended to discolor the tissue and to stiffen the porcine leaflet and the aortic wall. Although the impregnation of protamine did not seem to significantly alter the crosslinking density of the epoxy compound fixed biological tissues, the increase of the stiffness of the heparinized tissues may cause concerns in some clinical applications. © 1995 John Wiley & Sons, Inc.