Carpet Pile Research Articles

An investigation on the effects of heat-setting process on the properties of polypropylene bulked continuous filament yarns

Heat-set bulked continuous filament (BCF) polypropylene yarns constitute one of the most important pile yarns used in the production of machine-woven carpets. As carpets made from non-heat-set BCF polypropylene yarns lack resiliency and loss of appearance, heat setting of BCF yarns has proved to be very useful in overcoming these deficiencies. This work aimed to investigate the effects of dry steam heat setting on the structure, properties and structural–property relationship of industrially produced heat-set BCF polypropylene yarns. It was ascertained that while tenacity, initial modulus, bending rigidity, crimp contraction and shrinkage decrease as a result of heat setting process, there is an increase in the yarn linear density. Because of these mechanical changes, the resiliency of BCF polypropylene yarns is positively affected by heat-setting process, and as a result, a better wear and look for the carpet pile yarns. Changes in mechanical properties result from microstructural changes, namely, recrystallization induced by heat-setting process. Recrystallization leads to a higher overall crystallinity, with a higher number of smaller crystallites giving improved orientation. Lower initial modulus leads to a lower flexural rigidity or stiffness, thus giving rise to a better resiliency of heat-set BCF polypropylene yarns. This is related to the formation of smaller size crystallites in spite of the higher degree of crystallinity.

Flame retardancy behaviors and structural properties of polypropylene/nano‐SiO2composite textile filaments

AbstractThe number of efforts about modifying the properties of polymeric fibers by organic or inorganic particles has increased recently because of high‐tech applications of textiles. In addition to these attempts, the discovery of nanotechnology also leads to the development of nanoparticles for various end uses such as nanocomposite fibers. In this article, we aimed to produce slow burning or flame retardant polypropylene filaments for carpet pile yarns by incorporating SiO2nanoparticles into polymer. Therefore, we present the preparation of filaments incorporating 0.3, 1, and 3% SiO2nanoparticles and investigate the effects of nanoparticles on the flame retardancy and structural behavior of filaments. Polypropylene and nanoparticles were compounded by melt‐compounding using twin‐screw extruder before spinning. Filaments with trilobal cross sections were spun using pilot melt spinning equipment. The structural properties of nanocomposite fibers were analyzed using X‐ray difractometry, differential scanning calorymetry, scanning electron microscopy, and tensile tests. The flammability behaviors of filaments were evaluated using the oxygen index method. The effect of nanoparticles on structural properties and flame retardancy behaviors of filaments were summarized and discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Preliminary Outcomes of the SmartWheel Users’ Group Database: A Proposed Framework for Clinicians to Objectively Evaluate Manual Wheelchair Propulsion

Cowan RE, Boninger ML, Sawatzky BJ, Mazoyer BD, Cooper RA. Preliminary outcomes of the SmartWheel Users’ Group database: a proposed framework for clinicians to objectively evaluate manual wheelchair propulsion. Objectives To describe a standard clinical protocol for the objective assessment of manual wheelchair propulsion; to establish preliminary values for temporal and kinetic parameters derived from the protocol; and to develop graphical references and a proposed application process for use by clinicians. Design Case series. Setting Six research institutions that collect kinetic wheelchair propulsion data and contribute that data to an international data pool. Participants Subjects with spinal cord injury (N=128). Interventions Subjects propelled a wheelchair from a stationary position to a self-selected velocity across a hard tile surface, a low pile carpet, and up an Americans with Disabilities Act−compliant ramp. Unilateral kinetic data were obtained from subjects using a force and moment sensing pushrim. Main Outcome Measures Differences in self-selected velocity, peak resultant force, push frequency, and stroke length across all surfaces, relationship between (1) weight-normalized peak resultant force and self-selected velocity and (2) push frequency and self-selected velocity. Results Graphical references were generated for potential clinical use based on the relation between body weight−normalized peak resultant force, push frequency, and velocity. Self-selected velocity decreased (ramp < carpet < tile), peak resultant forces increased (ramp > carpet > tile), and push frequency and stroke length remained unchanged when compared across the different surfaces. Weight-normalized peak resultant force was a significant predictor of velocity on tile and ramp. Push frequency was a significant predictor of velocity on tile, carpet, and ramp. Conclusions We present preliminary data generated from a clinically practical manual wheelchair propulsion evaluation protocol and we describe a proposed method for clinicians to objectively evaluate manual wheelchair propulsion.

The Antimicrobial Effect of Benzalkonium Chloride on Some Pathogenic Microbes Observed on Fibers of Acrylic Carpet

In the presented research, the main aim is to investigate the antibacterial effectiveness of BAC solutions on acrylic fibers used in machinery carpet. An acrylic pile carpet laid in a public place for 30 days and the existence of some microbes were investigated on it. The antimicrobial effect of different BAC solutions for identified microbes was studied in vitro. The acrylic fibers were treated with the same different solutions of BAC as before and the antibacterial effectiveness was assessed by the zone of inhibition method in different times. Two pieces of carpet untreated and treated with BAC solution sewed together and laid for one week in the public place and the amounts of bacterial growth determined by colony count method and the results compared. Finally some mechanical properties of treated acrylic fibers measured after 30 days and compared with untreated one. The results showed the presence of some pathogenic microbes on the laid carpet such as Escherichia coli and Staphylococcus aureus. The inhalation time for treated acrylic fibers improved. The amount of colony growth on treated carpet reduced considerably and besides the mechanical tests results showed no significant deterioration effect of studied properties in comparing with untreated yarn.

The vertical distribution of house dust mite allergen in carpet and the effect of dry vacuum cleaning

Background Carpets are large reservoirs of the dust mite allergen Der p 1. The effect of vacuum cleaning on the distribution of Der p 1 in carpets is poorly understood. Methods Samples were cut from 7 used household carpets, all over 5 years of age. From each carpet, 10 samples were left untreated, 10 vacuumed with an upright vacuum cleaner, and 10 vacuumed with a canister vacuum cleaner. Each section was then cut into 3 horizontal layers: the top 2 mm, the remainder of the carpet pile, and the carpet base. The mass of Der p 1 as a proportion of carpet volume was then determined. Results The concentrations of Der p 1 in each depth layer varied considerably between the 7 untreated carpets. In the top layer, Der p 1 concentrations were (median; 25th–75th percentiles): 41.9; 28.3–92.6 pg/mm 3. For the middle layer they were similar (38.1; 22.4–108.5 pg/mm 3), and for the carpet base, higher (212.4; 98.8–456.2 pg/mm 3). In most cases, cleaning using either type of vacuum cleaner resulted in no significant reduction in allergen concentration throughout all depth layers. A subset of carpets showed an apparent increase in Der p 1 concentration in one or more layers following vacuum cleaning. In all tests Der p 1 was collected in the vacuum cleaners’ filter bags. Conclusions The depth-distribution of Der p 1 differs widely amongst used carpets. Vacuum cleaning changes the distribution of Der p 1 within such carpets but does not necessarily result in a reduction in the overall content.

Application of Gaseous Ozone for Inactivation of Bacillus subtilis Spores

The effectiveness of gaseous ozone (O3) as a disinfectant was tested on Bacillus subtilis spores, which share the same physiological characteristics as Bacillus anthracis spores that cause the anthrax disease. Spores dried on surfaces of different carrier material were exposed to O3 gas in the range of 500–5000 ppm and at relative humidity (RH) of 70–95%. Gaseous O3 was found to be very effective against the B. subtilis spores, and at O3 concentrations as low as 3 mg/L (1500 ppm), ∼3-log inactivation was obtained within 4 hr of exposure. The inactivation curves consisted of a short lag phase followed by an exponential decrease in the number of surviving spores. Prehydration of the bacterial spores has eliminated the initial lag phase. The inactivation rate increased with increasing O3 concentration but not ∼3 mg/L. The inactivation rate also increased with increase in RH. Different survival curves were obtained for various surfaces used to carry spores. Inactivation rates of spores on glass, a vinyl floor tile, and office paper were nearly the same. Whereas cut pile carpet and hardwood flooring surfaces resulted in much lower inactivation rates, another type of carpet (loop pile) showed significant enhancement in the inactivation of the spores.

Domestic Terror and Poe's Arabesque Interior

THUMBING THROUGH THE PAGES of a May 1840 Burton's Gentleman's Magazine reader alights on a curious essay about of interior design written by editor, Edgar Allan Poe. Beginning a quote from Hegel that affirms philosophy as utterly useless and therefore sublimest of pursuits, Poe proceeds to argue for a philosophical approach to internal decoration that implicitly establishes furniture as a potential source of sublime (Furniture 243). Poe's subsequent claim, though, is that this philosophy of furniture is nevertheless more imperfectly understood by Americans than by any civilized nation on earth, to which he adds that in terms of internal decoration the English are supreme and the Yankees alone are preposterous (243). Considering Yankee composition of Poe's own audience, it is not surprising that critical response to Philosophy of Furniture stresses its intentionally tone (The Edgar Allen Poe Society of Baltimore). What this dominant approach ignores, though, is Poe's investment in modeling cultivated for an American audience whose own primitive precludes domestic access to sublime. (1) To this end, Poe, posturing as cultural critic, concludes article an invitation to his readers to watch as he sketches a small and not ostentatious chamber whose decorations no fault can be found (244). Prominent among these faultless decorations is arabesque. An analysis of Poe's arabesque reveals link between his humorous theory of interior design and his theory of literary affect, ultimately providing scholar a pattern that elaborates hitherto under-appreciated influence of Orientalism on Poe's aesthetics. (2) Ensconced in voluminous drapes, thick carpet pile, and diffuse light, proprietor of chamber with whose decorations no fault can be found dozes peacefully as Poe ushers his readers through a diorama of eclectic furnishings which include a Saxony rug, Sevres vases, and an Argand lamp. The atmosphere is one in which Poe insists speaks in all. This sphere of repose is not only achieved through obscure lighting and plush materials, it is conducted by meditative arabesque designs which adorn wallpaper, carpet, and all upholstery of this nature. However, when these very same arabesque images appear in Poe's fiction, they effect not pleasant dreaming but nightmarish terror. Indeed, only a few months prior to appearance of Burton's article, Poe had published Tales of Grotesque and Arabesque, a document in which he credits his peculiar taste for arabesque establishing tenor of that defines his serious tales. (3) The arabesque, which operates as a rigid representation of leisure in Philosophy of Furniture, becomes animate in these serious tales--a metamorphosis which allows terror to infiltrate domestic sphere. What then is relationship between Poe's use of static arabesque as a signifier of invigorated American and his use of animate arabesque as a signified American terror? Answering why Poe perverts into terror necessitates unraveling arabesque convolutions of his Romantic aesthetics. In his major essays on style, Poetic Principle (1848) and Philosophy of Composition (1846), Poe mimics voice of a traditional Continental Enlightenment aesthete when he extols supernal beauty, rational methods of composition, and equivalencies between morality and taste. In these public treatments of aesthetics, Poe ostensibly conforms to what Michael Davitt Bell has theorized as theory of American Romance, an approach which emphasizes balance and integration and is best exemplified by Nathaniel Hawthorne's definition of romance as controlled, serious, moral, and conservative (Bell, 36). However, if progressive project of Enlightenment was, as Horkheimer and Adorno put it, liberating men from fear and establishing their sovereignty, (3) Poe's tales of domestic terror, in particular, consciously undermine fearless, sovereign self and exhibit a predilection for an aesthetic reification not of Beautiful or moral, but of monstrous, grotesque and inhuman. …

Electrostatic control of domestic dust and allergen particles for improved air quality

Indoor air quality is an important issue, as exposure to indoor allergens has been associated with recent increases in the prevalence of allergic disease. Reduction of indoor allergen levels can therefore play an important role in the overall management of these patients. Reviewed here are two new electrostatic techniques for controlling domestic dust and allergenic particles. A technique to improve the removal of airborne allergens has demonstrated enhanced precipitation of particles by charged liquid sprays. Charged sprays can be produced by maximising the shearing of electrical double layers during atomisation of liquids from domestic pressure-pack (PP) devices. Electrostatically charged sprays removed up to 45% of the total mass of airborne dust particles. The effect on small particles (<2.0 μm) is most significant, the concentration of these being reduced by 73% by the charged spray, compared with just 59% by the equivalent uncharged spray. The removal of dust and allergen particles from normal carpets during vacuuming can be enhanced by the application of an electrostatically charged carpet care powder. Carpet powders, of the type used to deliver a fragrance to a domestic carpet, can be triboelectrically charged during delivery to above 1×10 −4 C/kg. It has been found that when this charged powder was applied to carpets, up to 99% of dust was removed, 15% more than when no powder was applied. Application of a standard, uncharged powder resulted in significantly less dust being recovered. It was proposed that the charged powder particles attract dust and allergen from within the carpet pile, and that these large agglomerates were more efficiently removed by vacuum cleaning. These novel techniques for dust and allergen particle control in the domestic environment represent new applications for electrostatic technology. They come at a time of increased public awareness and concern for indoor air quality, providing potential tools for allergen mitigation in the management of allergic disease patients.

Hydrolytic Degradation of Nylon 66 Pile Carpet Fibers

Hydrolytic degradation of nylon 66 fibers for sculpturing pile carpets is investigated in this study. Applying an aqueous solution of para-toluenesulfonic acid catalyzes the hydrolysis of nylon 66 and degrades the fibers. The reduced strength of the fibers enables sculpturing of pile carpets. The morphology of the degraded fiber tips is reported as a function of treatment conditions. Insufficient steamer residence time leads to an agglom eration of fiber tips within a tuft rather than fiber degradation, and results in a rougher tactile feel. The first-order kinetic parameters reported in the literature are used in conjunction with a simple, one-dimensional, unsteady-state heat conduction model to represent the sculpturing process. The extents of degradation predicted for the longer treatment times agree with experimentally measured values.

Optical Property of Cut Pile Carpet and Loop Pile Carpet

Optical Property of Cut Pile Carpet and Loop Pile Carpet

Part I: Wear Model of Cut Pile Carpet

Modem probability fracture mechanics forms the foundation of Carnaby's carpet durability theory. On the basis of this theory, mathematical models have been developed to predict the wear life of wool cut pile carpet. In this paper, the existing models are upgraded to provide an accurate mathematical expression of Carnaby's theory, in line with the current advances in knowledge about the fatigue mechanism of wear in wool carpet, The life distribution function proposed by Camaby is redefined to achieve a direct measurement of the model parameters. The advanced model gives a better fit to the experimental observations than the previous one.

Part II: Wear Model of Loop Pile Carpet

A two-stage wear mechanism in a loop pile wool carpet is confirmed by current experi mental studies. A loop pile wear model is then developed on the basis of the two-stage wear mechanism. This model meets the initial and final conditions of carpet wear and shows that a loop pile construction of similar pile density has a longer life than the cut pile construction, as proved by observations. The sensitivity tests show that the delay of second-stage wear is insignificant to the wear life of a loop pile wool carpet, whereas the influence of the shape parameters b and B of the life distributions is remarkable.

Measurement of airborne fungal spore dispersal from three types of flooring materials

Research was conducted in an experimental roomto measure the effect of human activity onairborne dispersal of settled fungal sporesfrom carpet and vinyl tile flooring. A seriesof experiments were conducted in whichcommercial loop pile carpet, residential cutpile carpet, or vinyl tile installed in theexperimental room were contaminated with Penicillium chrysogenum spores. The flooringmaterials were contaminated to two differentlevels (106 and 107 colony formingunits per square meter [c.f.u./m2] offlooring surface). Airborne culturable andtotal P. chrysogenum concentrations weremeasured using Andersen single-stage impactorsamplers and Burkard personal slide impactorsamplers, respectively. Bioaerosolconcentrations were measured at floor level, 1meter, and the adult breathing zone (1.5 meter)heights before and after human activityconsisting of walking in a prescribed patternfor 1 minute in the room. Airborne P.chrysogenum concentrations were greater withthe higher surface loading for all threeflooring materials. For all flooring materialsthere was no significant difference betweensampler locations, although the data from the1-meter location were the highest, followed bythe floor level and the breathing zonelocations, respectively. The data from theseexperiments indicate that while a very smallfraction of culturable P. chrysogenumspores present on flooring materials wereaerosolized by walking, relatively highairborne concentrations of spores maybere-entrained from contaminated materials. Theairborne P. chrysogenum concentrationswere significantly higher after walking on cutpile carpet than with the other two flooringmaterials at both contamination levels, withthe differences in concentration often ≥ 2orders of magnitude. No differences weremeasured in airborne culturable P.chrysogenum between vinyl flooring and looppile carpet at both contamination levels. Total spore data from the experiments with the107 c.f.u./m2 contamination levelindicated that walking on loop pile carpetproduced higher airborne spore concentrationsthan similarly contaminated vinyl tile althoughno significant difference was observed at the106 c.f.u./m2 level.

Electrostatic targeting for allergen removal and pest control applications

Today in the United Kingdom, approximately one in seven infants are diagnosed with asthma in the first six months of life. There has been a dramatic increase in recent years, and asthma-related drugs now account for approximately 11% of the total prescription costs to the National Health in the UK (Department of Health, Asthma and Epidemiology, HMSO, 1995). In addition to medication, preventative measures include attempts to exclude the allergen from the domestic environment. This requires careful control of the most common asthma allergen, Der p1, which is conveyed by the waste products produced by the house dust mite ( Dermatophagoides pteronyssinus). Acaricides may be used to kill the dust mites, but these have to be combined with allergen denaturing agents if eradication of the allergen is sought. Mechanical barriers such as mattress and pillow covers offer some protection from contact with the allergen, but often with a varying degree of success. High levels of allergen carriers are also known to exist in carpeting, and this can lead to a particularly undesirable environment for infants who frequently crawl with their faces close to, and sometimes in contact with, the carpet pile. Inhalation of allergen is usually unavoidable in this situation. Research has indicated that the use of electret fibres can dramatically enhance the anchoring of allergen carriers in the carpet pile. Electrostatic adhesion of the carriers to the electret fibres ensures that for normal traffic conditions, such as walking, crawling, playing etc, much less dust is released from the carpet; thus reducing the probability of inhalation. Dispensing domestic products in aerosol form has undoubtedly been a commercial success; offering considerable consumer advantages in applications ranging from paints, polishes and insecticides. The targeting of products in aerosol form may not, however, be optimised with a high proportion of the product often missing its target. It is well known that electrostatic spraying can enhance targeting, but this technology is normally limited to industrial processes such as paint and powder coating. A novel and unique aerosol package has been developed which charges the aerosol on delivery in a controlled manner. The Smartseeker™(™Smartseeker is a trademark of Reckitt Benckiser) insect seeking technology is now incorporated into a commercial aerosol insecticide, and is the world's first electrostatically optimised aerosol can which requires no active energy source. Flying insect knock-down is enhanced by up to 34% with this technology.

Electrostatic enhancement of dust and allergen removal from carpets

The function of a simple fragranced carpet powder formulation has been extended beyond just the addition of fragrance to a room and the masking of malodours. A carpet powder dispensing pack was developed that transferred a high electrostatic charge (>1×10 −4 C/kg) onto the powder as it was dispensed. The amount of dust removed from a carpet by vacuum cleaning was measured. It was found that when a charged carpet powder was added to a polypropylene, wool or nylon carpet, significantly more dust was removed ( P<0.05) as compared to no carpet powder or uncharged carpet powder. It was proposed that if an electrostatically charged powder were applied to a carpet, the charged powder particles would attract dust and allergen from within the carpet pile. These would then adhere to the powder particles to form agglomerates similar to those found in electrophotocopier two-component systems. These agglomerates would be large and therefore would be more efficiently removed by vacuum cleaning than dust alone. This effect offers major benefits when attempting to remove dust and allergen from the home environment to reduce asthma stimulus.

ENERGY EXPENDITURE OF WALKING IN PERSONS WITH MULTIPLE SCLEROSIS USING THE TRI-TRAC ACCELEROMETER

Multiple sclerosis (MS) can affect gait in many ways. Muscle spasticity, weakness, cocontraction, sensory loss, and ataxia are symptoms that adversely affect walking resulting in a loss of efficiency and increased energy expenditure (EE). Accelerometry may be a clinical tool for estimating EE in this population to determine potential independence and physical activity. Seventeen subjects with MS (Median EDSS 2.5; range 1.0 – 6.5) walked over a low pile carpet course for 5 min at a self-selected velocity while wearing the TriTrac R3D accelerometer and the Aerosport 2000 metabolic analyzer. Gait was analyzed using videography and the Gair Assessment Rating Scale (GARS). Paired t-test revealed an average underestimation of EE by the Tri-trac equations of 24% (range + 4 to −103%). Regression analysis resulted in the following equation to predict EE from acceleration data and other clinically relevant: EE = −3.1 + (0.038 * WT) + (0.034 * Velocity) + (0.069 * GARS) + (0.0015 * MVM) (WT - weight; MVM - Mean Vector Magnitude) R = 0.83 R2 = 0.69 SEE = 0.54 p < .05. This regression model would result in less error in estimating EE in persons with MS who have gait abnormalities (± 0.43 METS) when using the Tritrac accelerometer. Sponsored by the Department of Veterans Affairs û Rehabilitation R & D.

The Effect of Selected Residential Carpet and Pad on the Balance of Healthy Older Adults

The purpose of this research was to determine whether selected residential carpet and pad contributed to balance problems among healthy, community-dwelling older adults. Twenty-five older adults (mean age 73.25; SD± 7.48) were recruited, and balance was measured using the NeuroCom Computerized Posturography balance machine. Participants were exposed to the Sensory Organization Test while standing on the selected residential carpet (i.e., a 36-ounce, 1/2-inch pile height, 1/8-inch gauge, cut pile carpet) and pad (i.e., a rebonded polyurethane, 6-pound density, 7/16-inch thick padding). Postural sway significantly increased on the carpet only when participants had their eyes closed and the forceplate on the balance machine moved. Balance strategy was not affected by the carpet. Participants were able to adjust to the sensory limitations by adopting an ankle strategy regardless of the floor surface. The results of this study indicate limited participant difficulty maintaining static balance when standing on the selected carpet.

Scholarship and a Controversial Group of Safavid Carpets

Although Islamic textiles, particularly the knotted pile carpet, are held in high esteem by their cultures of origin, they have more often than not been subjected to unreliable scholarship. This is particulalrly the case with Persian carpets because there are so few examples surviving from earlier periods. The earliest Persian carpets, as opposed to depictions of carpets on miniatures, that can be reliably dated are from the sixteenth century. A group of Safavid Persian carpets usually described as the Saltings, has been particularly misunderstood, as they have been, for reasons that are now unconvincing, labeled by several notable scholars as products of nineteenth century Turkish looms. Rencently, however, there has been a fresh approach to the subject, and a re-evaluation of previously held theories is in order. New documentary evidence and up-to-date methods of analysis have cast doubt upon previous scholarship. Records from the Topkapi Palace, where most of the surviving Saltings were found, have been obtained for a number of specimens. The present author has dealt with metallurgical questions relating to the use of a silver -wrapped thread used in the fields of these rugs. As most of them show elaborate inscriptions, these have been carefully translated, and even here there is information bearing on the question of whether they are Sfavid or late Turkish rugs. The convergence of a number of specialists, each investigating a particular aspect of these carpets, may serve as a model for how complex issues of art history may be resolved.

The Effect of Residential Carpeting on the Gait of Healthy, Community-Dwelling Older Adults

The purpose of this research study was to determine whether selected residential carpet and pad contributed to gait problems among healthy, community-dwelling older adults. Twenty-five older adults (mean age 73.25; S.D. 7.48) were recruited through various organizations located in West Texas. Subjects were free from existing conditions (e.g., severe orthopedic problems, neurological disorders such as Parkinson's disease, severe visual diseases, inner ear diseases, and inner ear infections) that might have affected balance and gait control. Gait speed, number of steps, manner of turning, weaving, sitting to standing, standing to sitting, timed one-leg stance, and changes in gait speed were measured while subjects walked a 12-foot gait course. The gait course consisted of residential carpet (i.e., a 36-ounce, 112 in. pile height, 1/8 in. gauge, cut pile carpet) and pad (i.e., a rebonded polyurethane, six-pound density, 7/16 in. thick padding), and vinyl tile. The older adults walked significantly more slowly on the carpet versus the vinyl tile, suggesting that these subjects were more hesitant when they encountered a compliant sugace. None of the other gait measures were statistically significant. The results of this study indicated limited subject dzficulty when walking on the selected carpet.

Organic Vapors Emitted from the Plumes of Pool Fires on Carpet Material

When an accelerant is poured onto an absorbent material, such as carpet pile, it is absorbed into the material. Once ignited, the accelerant is heated and the carpet pile acts as a wick, which feeds evaporating accelerant into the fire plume. This paper deals with the analysis of the volatile material on the edge of the fire plume. Charcoal strips have been used to adsorb the volatiles and Gas Chromatography/Mass Spectrometry used to analyze the extracts from the charcoal strips. The technique has been used successfully to identify the accelerant burnt on the pile, from the chromatographic profile of the gases in the plume.