bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hot‐surface ignition temperatures of dust layers
Authors: Miron Yael , Lazzara Charles P. 
Published: May 2005

AbstractMinimum dust layer ignition temperatures on a hot surface were determined for several dusts, using a test procedure recommended by the National Academy of Sciences. The dusts included coal, three oil shales, lycopodium spores, corn starch, grain and brass powder. For a few of the dusts the effects of particle size and layer thickness on the minimum ignition temperatures were examined. Test results were repeatable and reliable for the fuels, the lycopodium and the brass powder. The minimum hot‐surface ignition temperatures of 12.7‐mm thick layers of these dusts ranged from 160°C for brass to 290°C for 20‐gal ton−1oil shale. Flaming combustion was observed only with the brass powder. The minimum ignition temperatures decreased with thicker layers and with smaller particle sizes. Some difficulties were encountered with the corn starch and grain dusts. During heating, the starch charred and expanded; the grain dust swelled and distorted. The test was found acceptable for the purpose of determining the minimum layer ignition temperature of a variety of dusts. To prevent fire hazards due to smoldering or flaming dust layers the temperatures of surfaces on which combustible dusts accumulate should be lower than the minimum hot‐surface ignition temperatures of the dusts.
Theoretical estimation of critical fire load close to an unprotected steel member
Authors: Keski‐Rahkonen O. 
Published: May 2005

AbstractA theoretical model is set up to estimate critical fire loads close to unprotected steel members in large rooms. The members are assumed to have a critical temperature calculated from external loads. A constant fraction of the energy of the fire load is assumed to be absorbed by steel during burning. Rapid overall and zone burning with constant velocity are shown to yield the same critical fire load. Therefore it is concluded that these loads also give conservative estimates for the critical load in a real fire, the development of which lies between these two extremes. A general form of calculation is given. For rough estimates, 5% mass of the fire load as compared to the steel mass could be allowed.
Oxygen index and minimum limiting rates of polymer combustion
Authors: Zhubanov T. B. , Gibov K. M. 
Published: May 2005

AbstractThe influence of the initial temperature and thermal loss upon the oxygen index and burning rates of polymethylmethacrylate (PMMA), polystyrene (PS) and polyoxymethylene (POM) has been studied. It has been shown that the temperature profiles in the proximity of the burning surface are identical under the critical conditions for each of the polymers. Direct measurements of flame–polymer heat flows have shown that with an increase in initial temperature from 25° up to 200°C the heat flow decreases approximately by a factor of 2. An analogous situation is also observed with change in the thermal loss value in the condensed phase. These data are confirmed by linear pyrolysis experiments. In all experiments under critical conditions the oxygen concentration indicates the constant mass decomposition rate for each polymer. With a decrease in the outlet velocity of the combustibles below this value, which is specific to each polymer, extinction occurs.
On the thermal ignition of combustible materials
Authors: Mikkola Esko , Wichman Indrek S. 
Published: May 2005

AbstractFormulas are derived for the time to achieve the ignition temperature as a function of the incident heat flux and the various thermophysical material parameters for thermally thick, thermally thin and thermally intermediate solid combustibles. Predictions are compared with recent experimental data for various natural wood species and wood products, and to previous data for wood and thermoplastics. The correlations are excellent when (1) the physical parameters used as the axes of the plots are chosen consistent with those of the theoretical formulas and (2) the experiments and the materials do not violate any of the restrictions imposed by the theory. From these plots it is easy to estimate the minimum heat flux for ignition, which is of great importance both in practice and for making theoretical predictions.
An examination of piloted ignition characteristics of cellulosic materials using the ISO ignitability test
Authors: Toal B. R. , Silcock G. W. H. , Shields T. J. 
Published: May 2005

AbstractThe ISO Ignitability Test apparatus is used to determine the times to ignition for cellulosic materials under an incident radiative flux within the range 1‐‐5 kW/m2. A linear relationship is determined between time to ignition and incident flux, and a means of using these results to classify building materials is proposed, based upon an empirical flux‐time product.
Long‐term reproducibility of small‐scale tests used for measuring the flammability of conveyor belting
Authors: Mintz K. J. 
Published: May 2005

AbstractThree small‐scale flammability tests were evaluated for potential use in quality control. The small‐scale flame test produced excessive scatter of data, the hot‐plate ignition test gave reasonably reproducible data, but the critical oxygen index yielded superior results and is recommended for quality control testing.
Combustibility of building materials
Authors: Richardson Leslie R. , Brooks Mary E. 
Published: May 2005

AbstractUntil the 1960s ASTM E136 and CAN/ULC‐S114 test methods were adequate for determination of non‐combustibility in materials being used to construct most buildings. However, since then there has been a very large increase in the use of products that are considered safe for construction of buildings required to be noncombustible but which are classified as combustible by these simple pass/fail tests. Therefore, Forintek Canada Corp. have developed an approach to define the combustibility of these new materials, based upon their release of heat when tested using the ASTM E1354 cone calorimeter.
Surface parameters from small‐scale experiments used for measuring HCl transport and decay in fire atmospheres
Authors: Galloway F. M. , Hirschler M. M. , Smith G. F. 
Published: May 2005

AbstractThe decay of HCl was investigated in two small‐scale scenarios: pure HCl injection into a 31 chamber and combustion of plasticized PVC in a 2001 chamber. The effects investigated included (1) humidity, (2) temperature, (3) concentration of HCl and (4) wall material. Surface materials studied were PMMA, ceiling tile (front and back), Marinite, painted PMMA, unpainted gypsum board and cement. In view of the very rapid HCl decay in most of those surfaces, the effects were often examined with small ‘chips’ of materials in a PMMA chamber, with fresh walls for each experiment. Experiments were also carried out to investigate the effect of surface ageing, with painted gypsum board, painted PMMA and unpainted gypsum board walls. HCl decay is very fast in cement or unpainted gypsum board surface (almost impossible to saturate with HCl) and almost as fast on ceiling tile and Marinite. Saturation of HCl can be reached on painted gypsum board and painted PMMA surfaces, albeit at different rates. An earlier empirical model from mathematical fitting had been followed by a new HCl generation, transport and decay model, with a sound physical basis. This allowed calculations of parameters for all the surfaces used. Much work has already been done in devising and writing a zone model for use together with fire hazard models (particularly the NIST model, FAST) to calculate correct HCL concentrations in various fire scenarios. This work, which concludes the investigation of these two static fire scenarios for the surfaces analysed, represents one more step in the pursuit of that goal.
Effect of orientation on burning rate of solid combustible
Authors: Ohtani H. , Ohta K. , Uehara Y. 
Published: May 2005

AbstractThe effect of orientation on the combustion phenomena of a PMMA plate was studied experimentally. A PMMA plate was held by a sample holder made of insulation boards with only one face exposed to the air. Observation of burning inclined plates revealed that flame shape varied with inclination angle. The burning behavior of the upper surface of an inclined plate appeared to differ from that of the lower surface. However, the surface regression rate was found to depend on the inclination angle from the vertical plane. This rate for the upper surface was identical to that of the lower one if the absolute value of the inclination angle was identical, and was found to depend on empirical relationships involving natural convective heat transfer around a heated plate.
Note: Effect of some zinc chelates on the flammability and thermal behaviour of polypropylene
Authors: Gad A. M. , Khattab M. A. , Kandil S. H. , Dawoud A. F. , Soliman A. A. , El‐Sharkawy M. H. 
Published: May 2005

AbstractSome zinc chelates were prepared according to conventional methods, and were mixed with polypropylene in the presence and absence of a halogenated compound (Cereclor 70). The effect of these chelates on the flammability and thermal behaviour of polypropylene was studied by measuring the limiting oxygen index values and by the use of thermal analysis. This results showed that these chelates are ineffective in reducing the flammability of polypropylene but their effectiveness is enhanced to varying extents by the addition of Cereclor.
The effects of geometry and ignition mode on ignition times obtained using a cone calorimeter and ISO ignitability apparatus
Authors: Shields T. J. , Silcock G. W. , Murray J. J. 
Published: May 2005

AbstractThree timber‐based materials were investigated by subjecting them to a constant uniform heat flux in the range 20–70 kW m−2 using a Cone Calorimeter and the ISO Ignitability Apparatus. The specimens were examined in the vertical and horizontal orientations in the Cone Calorimeter using gas flame pilot, spark pilot and spontaneous methods of ignition. They were also studied using the ISO Ignitability Apparatus in the normal and inverted horizontal orientations using gas flame pilot and spontaneous methods of ignition. The results obtained are compared by specimen, orientation and mode of ignition.
Flame‐retardant treatment of some tropical timbers
Authors: Eboatu A. N. , Garba B. , Akpabio I. O. 
Published: May 2005

AbstractThe Superphosphate Fertilizer, to be referred to simply as fertilizer, was used to impregnate some tropical timbers. It was observed that this treatment drastically altered the thermal characteristics of these materials. The results are interpreted as arising from the fact that on heating, fertilizer evolves molecules that interfere with the chemistry of pyrolysis/combustion of wood cellulose.
Smoke development and engineering aspects of smoke‐extraction systems for atria in Hong Kong
Authors: Chow W. K. 
Published: May 2005

AbstractThe smoke‐filling process in an atrium is studied in this paper using the plume equation of Thomas et al. A time constant is proposed to describe the smoke‐filling time of the atrium space. This parameter is recommended to be used as a guideline for local projects in determining whether a smoke‐extraction system has to be installed. Finally, the engineering aspects to be noted in designing smoke‐extraction systems for an atrium space are introduced.
Comparison of the smoke toxicity of four vinyl wire and cable compounds using different test methods
Authors: Hirschler Marcelo M. , Grand Arthur F. 
Published: May 2005

AbstractFour vinyl wire and cable materials were tested using five smoke toxic potency test methods: the NBS cup furnace test (in its flaming and non‐flaming modes), the NIST radiant test, the NIBS IT50test (also using the radiant apparatus) and the UPITT test. One of the materials is a standard poly(vinyl chloride) (PVC) flexible wire and cable material, used commercially for wire insulation. The three other materials tested represent a new family of vinyl thermoplastic elastomer alloys, which are advanced materials with good fire performance, particularly in terms of heat release and smoke obscuration. It was found that the smokes from all four materials are similar in terms of their toxic potencies, and that they are all within the ‘common’ range of toxic potency found. In particular, the toxic potencies of the smoke from the new vinyl thermoplastic elastomer alloys are not significantly different from those of other traditional vinyl wire and cable compounds. The results of the tests were also interpreted in terms of the toxicities and concentrations of the individual gases emitted. The fractional effective dose of the toxicants analysed was sufficient to account for the toxicity of the smoke for the NBS cup furnace and the NISt radiant test. It was not able to account for the toxicity found in the UPITT test. The adequacy of the test protocols themselves was also investigated. It was found that the UPITT and the NIBS IT50method are inadequate for measurement of smoke toxicity. It was also found that the NIST radiant test protocol is the one most likely to lead to the smallest amount of future testing.
One‐ and two‐sided burning of thermally thin materials
Authors: Ohlemiller T. , Shields J. 
Published: May 2005

AbstractThe rate of heat release from a thermally thin material burning on both sides will be more than twice the value seen when only one side is burning. Two simplified models demonstrate that this is a consequence of the Arrhenius temperature dependence of the gasification rate of the solid. Experiments carried out on three composite materials over a range of incident heat fluxes confirm this effect. It is inferred that a further consequence of this heat release enhancement is an increased tendency for concurrent flame spread in the two‐sided burning case. Materials whose application could lead to two‐sided burning should thus be assessed in this mode to obtain a true picture of their flammability potential.
Note: Fire test data available for your purpose
Authors: Opstad Kristen , Lønvik Lars Einar 
Published: May 2005

AbstractThe EUREFIC (European Reaction to Fire Classification) has produced many fire test data made available through a Data Converting System (DCS). DCS is a simple PC‐based program which transfers data logger files into a standard fire test data format, given by FDMS (Fire Data Management System). DCS is also capable of transferring standard data files into data formats of common spreadsheets. The EUREFIC programme has made two models for assessing large‐scale performance of test materials. These models are integrated into a PC program called CT (Cone Tools).
The study and application of LL flame retardant
Authors: Wenqing Qin , Feng Li 
Published: May 2005

AbstractInorganic flame retardants containing water are less likely to produce toxic gases and smoke during combustion. The raw materials used to synthesize inorganic flame retardants are inexpensive and readily available. Therefore it is appropriate to research and synthesize these kinds of flame retardants and use them to produce building materials that have improved flame retardance and a low price and that constitute no environmental hazards. This paper introduces one kind of liquid,‘LL flame retardant’, which is the product of the reaction of phosphoric acid and aluminium hydroxide under specified reaction conditions. This flame retardant can be used for fire‐retardant coating and can also treat the combustible materials, such as fabrics, paper and wood. This paper describes the preparations, properties and the mechanism of flame‐retardant action of this additive.
Rate of heat release and ignitability indices for surface linings
Authors: Kokkala Matti A. , Thomas Philip H. , Karlsson Björn 
Published: May 2005

AbstractDimensional analysis is applied to one form of fire growth in a compartment to derive two indices for the classification of linings, an ignitability index and a rate of heat release index, that can be combined into a fire growth parameter, which here is made proportional to the time to flashover in the internationally standardized Room/Corner Test. The ignitability index is the inverse of the time to ignition. The rate of heat release index is obtained by integrating the rate of heat release in time, weighted in such a way that the values of rate of heat release immediately after ignition are of higher importance than those at later times. Both indices are determined from test results of the Cone Calorimeter.
Urinary phenylethylamine excretion in phobic and obsessive patients
Authors: Theofilopoulos N. , Flaskos J. , George A. J. 
Published: May 2005

AbstractUrinary excretion of phenylethylamine (PEA) was determined in 19 agoraphobic, 15 obsessive compulsive and 10 neurotic depressive outpatients, and 17 healthy volunteers. Variations in urinary PEA concentrations did not appear to correlate with any of the diagnostic groups.
Intermittent micromotion and polyethylene particles inhibit bone ingrowth into titanium chambers in rabbits
Authors: Goodman Stuart B. , Aspenberg Per , Song Yong , Regula Donald , Lidgren Lars 
Published: May 2005

AbstractWe performed a histomorphological and morphometric analysis of the effects of short daily periods of micromotion and phagocytosable particles of high density polyethylene (PE) on bone ingrowth into a 1 × 1 × 5 mm canal within a titanium chamber in rabbits. The micromotion chamber (MC) was implanted in the tibia of nine mature New Zealand white rabbits. After osseointegration and first harvest of tissue, 40 micromotions (amplitude = 0.5 mm) were applied daily at a rate of 1 Hz for a 3‐week period. The tissue within the chamber was then harvested. For the second treatment, PE particles (108/mL) were placed within the canal. The tissue in the chamber was harvested 3 weeks later. The next treatment was a 3‐week rest period, in which neither micromotion nor particles were utilized; a harvest followed. The final treatment combined PE particles and micromotion, followed by a harvest 3 weeks later. Sections from control harvests contained extensive trabecular bone arranged longitudinally throughout the canal in a fibrovascular stroma. Micromotion produced longitudinally oriented fibrous tissue within the chamber. PE particles were associated with macrophages, surrounding and engulfing the birefringent particles. The combination of particles and micromotion produced a fibrous stroma laden with macrophages. PE particles and micromotion, alone or together, produced a similar effect in inhibiting bone ingrowth, compared to nonmoved chambers without particles. In this short‐term experiment, no additive or potentiating effect of these two stimuli could be demonstrated. © 1995 John Wiley & Sons, Inc.
The separation of flour into fractions of different protein contents by means of air classification
Authors: Jones C. R. , Halton P. , Stevens D. J. 
Published: May 2005

AbstractFractions of markedly different protein contents may be obtained by air‐classifying flour (in the sub‐sieve range) at cut sizes of about 17 and 35 μ respectively. Of these fractions, the fine, 1 (of high protein content), contains fragments of interstitial endosperm protein and small starch granules; the intermediate, 2 (low protein), mainly large starch granules; the coarse, 3, fragments of endosperm cells. The yields and protein contents of the fractions vary with different wheats; the yields of 1 and 2 may be greatly increased through suitably grinding the flour after milling.In general, 1 may be used for raising the protein content of flours deficient in protein to a level suitable for bread‐making. The amount of 1 required depends on its protein contents and on whether it came from a hard or soft wheat, the hard wheat fraction having better bread‐making qualities. The resulting variation in the proportion of 1 required in the blend causes variation in the proportion of other particulate materials introduced with 1, in which they have become concentrated during the air classification. These include diastatically active agents and finely divided discolouring matter; the level of the former reached in the blend greatly affects its bread‐making value. Pre‐grinding of the flour may be helpful in this respect.When chlorinated, 2 is potentially useful for making light‐structured cakes, but hard English wheats have mainly given less satisfactory results than soft. Under certain conditions, 3, with or without 2, may be better for biscuit‐making than the parent flour.
Problems in large‐scale culture of H. pertussis
Authors: Billaudelle H. , Hedén C.‐G. , Malmgren B. 
Published: May 2005

AbstractA study of factors affecting the reproducibility and yields in cultivations of H. pertussis (the whooping cough organism). The search for suitable media led to the development of a new kind of blood medium suitable for pre‐cultures. Sterility of the blood additive could be ensured by filtration, and contamination on starting the freeze‐dried cells was avoided by the use of a special kind of ampoule.In the course of studies of different cultivation techniques a 6,000 ml ‘pulsaerator’ was found to be ideal for the preparation of ordinary small batches. Inoculation density, aeration and other factors affecting the yield were studied and a culture cycle suitable for preparing 500 l. batches was developed.
Distribution of bacterial cells within fibrous air sterilization filters
Authors: Aiba Shuichi , Kodama Tohru , Sakamoto Hideo 
Published: May 2005

AbstractProbability theory has been applied to the analysis of bacterial distribution within a fibrous air sterilization filter. For a long filter layer, to which the so‐called ‘log‐penetration’ law is no longer applicable, the probability theory is considered to be effective in interpreting the distribution data.The effects of the diameter, volume fraction and moisture content of the glass‐fibre on the longitudinal distribution of bacterial cells, were studied. The distribution was estimated beyond the experimental data points. This estimation will be of use for predicting the ‘life’ of an air sterilization filter.
The effect of agitation on the rate of acid formation byLactobacillus delbrueckii
Authors: Kempe Lloyd L. , West Ronald E. 
Published: May 2005

AbstractThe effect of agitation on the rate of acid formation by the microaerophilic organismLactobacillus delbrueckiiwas studied. Fermentations were conducted at constant temperature and pH, and with the continuous addition of a nutrilite source. The range of agitator speeds was from 85 to 720 rev/min.The acid formation rate was found to increase with increasing agitator speeds and decrease with decreasing speeds if corn‐steep liquor was the nutrilite source. No effect of agitation was observed with yeast extract as the nutrilite source.The data from corn‐steep liquor media were found to be consistent with a mass transfer mechanism, but did not warrant a conclusion as to the specific nature of the effect of agitation. It was concluded, however, that the effect of agitation on the acid formation rate was at most very small.