bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the flammability of cotton bales
Authors: Wakelyn P.J. , Hughs S.E. 
Published: January 2003

Abstract Bales of cotton were classified by the International Maritime Organization (IMO) code regulations as a flammable solid (Class 4.1), which required hazardous goods papers to accompany waterborne shipments. Various scientific investigations were conducted to evaluate the flammability hazard of bales of cotton to determine if this hazardous designation was valid. Cigarette (NFPA 261/ ASTM E1352), match (NFPA 705) and open flame (CA TB 129) tests were conducted; the potential for self‐heating and spontaneous combustion was evaluated; and the potential of cotton bales sustaining smouldering combustion in their interiors at various compression densities was studied. These studies showed that bales of cotton should not be required to have the hazardous designation, ‘flammable solid’, and led to the IMO and the US Department of Transportation (DOT) removing the designation for baled cotton [compressed to a density of 360kg/m3(22.4lb/ft3) or greater; meets ISO 8115], with effect from 1 January 1999. Published in 2002 John Wiley & Sons, Ltd.
Use of cone calorimetry to quantify the burning hazard of apparel fabrics
Authors: Nazaré Shonali , Kandola Baljinder , Horrocks A. Richard 
Published: January 2003

AbstractUK fire statistics reveal that there are 60–80 clothing‐related burns fatalities each year and nightwear is the garment category which is more likely to cause deaths. Existing test methods for assessing the burning behaviour of apparel fabrics do not quantify the fabrics for their potential burn injury hazard. In the present work an oxygen consumption or cone calorimetric technique has been used to study the heat release parameters of apparel fabrics. Experimental fabrics selected for this study represent those typically used in manufacturing nightwear. Reproducibility and repeatability have been tested for both thermally thin and thick specimens in the form of single and multi‐layered fabrics, respectively. The effect of varying incident heat flux enabled the derivation of critical heat flux (CHF), peak heat release (PHRR) under zero incident heat flux and fire growth index (FIGRA). Ranking of fabrics for their potential burning hazard is discussed in terms of the relative magnitudes of these parameters. Copyright © 2002 John Wiley & Sons, Ltd.
A comparative analysis of protocols for measuring heat transmission through flame resistant materials: capturing the effects of thermal shrinkage
Authors: Crown E.M. , Dale J.D. , Bitner E. 
Published: January 2003

AbstractBench‐scale tests measuring the thermal protective performance of textile materials do not capture the effect of thermal shrinkage, primarily because of the planar geometry of the test device. The performance of single‐layer fabrics commonly used in protective garments is compared here following several protocols, including the use of a new cylindrical device as well as standard and modified ASTM, CGSB and ISO procedures, with and without a 6.35 mm air gap between the fabric and the sensor. Both the time to reach the second degree burn criterion and the time for the sensor to register a 24°C temperature rise were measured. Fabrics that shrink had reduced thermal protection when measured with the cylindrical device, compared with other tests. Two‐way analysis of variance indicated that, although the dependent measures differ significantly among fabrics, the nature and extent of those differences depend on the test used. One‐way analyses of variance indicate that each method differentiates among the fabrics. However, most tests in which the fabrics are in contact with the sensor rank heaviest fabrics as the most protective. Among the tests incorporating a space between the fabric and sensor, those using the cylindrical device differentiate best between lighter fabrics that shrink and those that do not. Regression analyses of data from bench scale tests with data from instrumented mannequin tests confirm the superiority of the cylindrical device in capturing the effects of both thermal shrinkage and fabric integrity. Copyright © 2002 John Wiley & Sons, Ltd
Pyrolysis and limiting oxygen indices of cotton fabrics graft copolymerized with oligomeric vinyl phosphonate and/or N‐methylolacrylamide
Authors: Masuko Fumi , Mitani Chizu , Sakamoto Munenori 
Published: January 2003

AbstractGraft copolymerization of an oligomeric vinyl phosphonate (FYR) and/or N‐methylolacrylamide was made onto cotton fabrics by a pad‐dry‐steam method. The limiting oxygen indices (LOI) of the treated samples confirmed the P–N synergism. Simultaneous TG/DTA measurements indicated that an exothermic peak appeared at a temperature near that where the main decomposition ended for the samples of high LOI (>24) values, either prepared with FYR or with both monomers. The peak temperature, however, did not correlate directly with the LOI of the sample. Curie‐point pyrolysis at 590°C was extensively studied on the treated samples by GC and GC–MS. Most of the main degradation products of the untreated cotton included hydroxyacetaldehyde, 1‐hydroxypropan‐2‐one, ethyl methyl ketone and acrolein. The amounts (per unit weight of the cellulose fraction of the samples) of these carbonyl compounds were much reduced by the introduction of a small amount of phosphorus into cotton. The decrease in the amount (per unit weight of the treated sample) of acrolein correlated highly with the increase in LOI. Copyright © 2002 John Wiley & Sons, Ltd.
Heat resistance and flammability of high performance fibres: A review
Authors: Bourbigot Serge , Flambard Xavier 
Published: January 2003

AbstractThe heat and flame resistance of high performance fibres are reviewed according to the literature data. The performance is discussed considering the physical and chemical structure of the fibres. Some selected high performance fibres are then evaluated using the cone calorimeter as a fire model to provide realistic data on the fire behaviour of the fibres. They are also examined in terms of heat resistance using combined TGA/DSC. The results are discussed and compared with literature data. Heterocyclic rigid‐rod polymers (poly (p‐phenylene‐2,6‐benzobisoxazole or PBO (Zylon®) and poly(2,6‐diimidazo (4,5‐b:4′,5′‐e) pyridinylene‐1,4 (2,5‐dihydroxy) phenylene or PIPD (M5)) exhibit the best performance (little or contribution to fire, low smoke and good heat resistance) and offer a good combination between heat and flame resistance and mechanical properties. Copyright © 2002 John Wiley & Sons, Ltd.
Toxic gaseous products of thermal decomposition and combustion of natural and synthetic fabrics with and without flame retardant
Authors: Wesolek Dorota , Kozlowski Ryszard 
Published: January 2003

AbstractThe results of studies on the toxicity of the gas products of thermal decomposition and combustion of natural and synthetic fabrics, as well as the influence of flame retardants (FR) on the emission of toxic products from fabrics are presented.Thermal decomposition and combustion were investigated according to the Polish standard PN‐88/B‐02855 that is not essentially different from the method described by the German standard DIN 53436.These gas products evolved from untreated and FR‐treated fabrics were subject to quantitative analysis, in order to determine environmental toxicity. They included carbon monoxide and dioxide as well as nitrogen oxides, hydrogen cyanide, hydrogen sulphide and sulphur dioxide.In order to evaluate the toxic properties of gas products emitted during thermal decomposition of the above fabrics, calculations were performed to determine specific emission of the toxic products as well as toximetric indices that relate results of analytical methods to those obtained by laboratories specializing in biological methods. Copyright © 2002 John Wiley & Sons, Ltd.
Possible phosphorus/halogen synergism in flame retardant textile backcoatings
Authors: Davies P.J. , Horrocks A.R. , Alderson A. 
Published: January 2003

AbstractSelected phosphorus/halogen flame retardant synergisms on cotton fabric substrates have been modelled using simple salt mixtures (sodium bromide and diammonium phosphate) and backcoating formulations based on combinations of ammonium polyphosphate, melamine phosphate and cyclic phosphonate with decabromodiphenyl oxide and/or hexabromocyclododecane and utilizing a chlorinated binder system. The results obtained suggest that there is a possibility of synergism as observed by limiting oxygen index. Linear modelling of the results suggests that the optimum phosphorus mole fraction occurs in the region of 0.15 to 0.45. Linear regression of the data shows an improved regression fit with the inclusion of an interaction term suggesting that there is a synergistic interaction taking place. Copyright © 2002 John Wiley & Sons, Ltd.
Flexible fire barriers based on natural nonwoven textiles
Authors: Kozlowski R. , Mieleniak B. , Muzyczek M. , Kubacki A. 
Published: January 2003

AbstractThese studies aimed at the development of natural fibre containing nonwoven fabrics with limited flammability. For 100% cellulosic fabrics, the presence of a flame retardant was essential for good fire performance, while for blended wool/hemp fabrics, (Wo+Hemp), moderate flame retardant levels were achieved without the addition of chemical treatment. Using cone calorimetry and LOI methods, fire performances were determined and all burning samples emitted low amounts of CO, although noticeable levels of CO2 were evident. Copyright © 2002 John Wiley & Sons, Ltd.
An investigation into the mechanism of flame retardancy and smoke suppression by melamine in flexible polyurethane foam
Authors: Price Dennis , Liu Yan , Milnes G. John , Hull Richard , Kandola Baljinder K. , Horrocks A. Richard 
Published: January 2003

AbstractThe mechanism of flame retardancy and smoke suppression by melamine in flexible polyurethane foam has been investigated using cone calorimetry, TG, DSC and pyrolysis/GC/MS. The cone calorimetric results indicate that the addition of melamine into polyurethane foam was very effective at reducing heat release rates and suppressing smoke and CO production during the initial combustion stage. GC/MS analysis showed that the volatiles evolved from polyurethane foam, pyrolysed at 350°C in air, consisted mainly of the 2,6‐ and 2,4‐ isomers of toluene diisocyanate. Such species together with other aromatic compounds are accepted as being the main contributors to smoke released from polyurethane foam in a fire. Cone calorimetry, DSC and pyrolysis/GC/MS experiments indicated that interaction occurs between melamine and the evolved toluene isocyanate fraction arising from the decomposition of polyurethane foam. The resulting polymeric structures so formed will reduce the amount of aromatic smoke precursors evolved thus suppressing smoke in the event of a fire. This polymeric structure will also degrade to a char, reducing the amount of combustibles volatilized and hence the rate of heat release. The char would form a protective layer on the surface of the polyurethane foam. A mechanism for this important melamine–isocyanate interaction is proposed. Copyright © 2002 John Wiley & Sons, Ltd.
Technical note: Usability evaluation of the modified CIE1976 Uniform‐Chromaticity scale for assessing image quality of visual display monitors
Authors: Lee WookGee , Kim SeongHwan , Lee SunKyu , Kim SangSoo 
Published: January 2003

AbstractWhite uniformity indicates the degree of uniform distribution of white color across the display screen and is one of the important inspection factors determining the image quality of a visual display unit (VDU). Experiments in which participants were confronted with 6 evaluation points embedded in 3 measurement groups on a VDU screen were conducted to gather the psychophysical data that include the levels of white uniformity obtained from participants and a colorimetric system (CA‐100). In an accuracy test, 37.12% of the participants showed the same conclusion led by the original CIE1976 criteria, and 62.88% of the participants showed the same conclusion led by the modified equation. In magnitude estimation evaluating the display's white uniformity, the magnitude score of the modified equation (0.36) was significantly larger than that of the original equation (0.32). It was concluded that the modified equation is more sensitive to the change of white uniformity. © 2003 Wiley Periodicals, Inc. Hum Factors Man 13: 85–95, 2003.
The α‐L‐Threofuranosyl‐(3′→2′)‐oligonucleotide System (‘TNA'): Synthesis and Pairing Properties
Authors: Schöning Kai‐Uwe , Scholz Peter , Wu Xiaolin , Guntha Sreenivasulu , Delgado Guillermo , Krishnamurthy Ramanarayanan , Eschenmoser Albert 
Published: January 2003

AbstractOur studies of α‐L‐Threofuranosyl‐(3′→2′)‐oligonucleotides (‘TNA') are part of a systematic experimental inquiry into the base‐pairing properties of potentially natural nucleic acid alternatives taken from RNA's close structural neighborhood. TNA is an efficient Watson‐Crick base‐pairing system and has the capability of informational cross‐pairing with both RNA and DNA. This property, together with the system's constitutional and (presumed) generational simplicity, warrants special scrutiny of TNA in the context of the search for chemical clues to RNA's origin.
Evidence that the β‐Peptide 14‐Helix is Stabilized by β3‐Residues with Side‐Chain Branching Adjacent to the β‐Carbon Atom
Authors: Raguse Tami L. , Lai Jonathan R. , Gellman Samuel H. 
Published: January 2003

AbstractOligomers of β‐substituted β‐amino acids (‘β3‐peptides') are known to adopt a helical secondary structure defined by 14‐membered ring hydrogen bonds ('14‐helix'). Here, we describe a deca‐β3‐peptide, 1, that does not adopt the 14‐helical conformation and that may prefer an alternative secondary structure. β3‐Peptide 1 is composed exclusively of residues with side chains that are not branched adjacent to the β‐C‐atom (β3‐hLeu, β3‐hLys, and β3‐hTyr). In contrast, an analogous β‐peptide, 2, containing β3‐hVal residues in place of the β3‐hLeu residues of 1, adopts a 14‐helical conformation in MeOH, according to CD data. These results illustrate the importance of side‐chain branching in determining the conformational preferences of β3‐peptides.
Allylsilane‐Modified Amino Acids from the Claisen Rearrangement
Authors: Mohamed Mustafa , Brook Michael A. 
Published: January 2003

AbstractThe Claisen rearrangement of the N‐protected, silylated allyl glycinates 11 and 12 led to the formation of allyl/silyl‐functionalized amino acids 13 and 14 in yields up to 80%. The diastereoisomer ratio varied from 2 : 1 to 29 : 1 for 11mb, and from 2 : 1 to 46 : 1 (syn/anti) for 12mb, depending on reaction conditions, as shown by X‐ray crystallographic analysis of 14mb. The relationship between the size of the alkyl groups on the chlorosilane reagent (Me2R″SiCl, R″=Cl, Me, t‐Bu, Ph) used as an enolate trap and the observed stereoselectivity was investigated in the case of the Ireland–Claisen variant. Me3SiCl gave the best results. However, the size of the alkyl groups on the silylated ester (Me2R″Si, R=Me, t‐Bu, Ph, i‐Pr) did not exert a significant effect on the diastereoselectivity or yield of the rearrangement.
A Study of the Stereochemical Course of β‐Oxygen Elimination with a Rhodium(I) Complex
Authors: Murakami Masahiro , Igawa Hideyuki 
Published: January 2003

AbstractThe stereochemical course of β‐oxygen elimination of an organorhodium(I) complex was investigated through the Rh‐catalyzed addition of phenylboronic acid to a chiral propargyl acetate to produce an allene. The degree of chirality transfer suggests that the β‐oxygen elimination takes place in both syn and anti modes.
Enantioselective Synthesis of β‐Amino Acids, Part 13
Authors: Gutiérrez‐García Víctor Manuel , Reyes‐Rangel Gloria , Muñoz‐Muñiz Omar , Juaristi Eusebio 
Published: January 2003

AbstractInexpensive acryloyl chloride was converted in 91% overall yield to two derivatives of β‐alanine, (R,R,R)‐6 and (R,R,S)‐6, containing two chiral auxiliaries. C‐Alkylation of (R,R,R)‐ and (R,R,S)‐6 via a dianion derivative, was performed by direct metallation with 2.2 equiv. of lithium hexamethyldisilazane (LHMDS) in THF at −78°. C‐Alkylation of (R,R,S)‐6‐Li2 (‘matched' pair of chiral auxiliaries) afforded the mono‐alkylated products 8–11 in 29–96% yield and 54–95% stereoselectivity. Employment of LiCl as an additive generally increased stereoselectivities, whereas the effect of HMPA as a cosolvent was erratic. Chemical correlation of the major diastereoisomer from the alkylation reactions with (S)‐α‐alkyl‐β‐alanine (12–15) showed that addition of the electrophile preferentially takes place on the enolate's Si‐face. This conclusion is also supported by molecular‐modeling studies (ab initio HF/3‐21G), which indicate that the lowest‐energy conformation for (R,R,S)‐6‐Li2 presents the more sterically hindered Re‐face of the enolate. The theoretical studies also predict a determining role for NLiO chelation in (R,R,S)‐6‐Li2, giving rise to an interesting ‘ion‐triplet' configuration for the dilithium dianion.
A Novel Concept for Combinatorial Chemistry in Solution: Synthesis of Highly Substituted Pyrrolidines by Multicomponent Domino Reactions
Authors: Tietze Lutz F. , Evers Holger , Töpken Enno 
Published: January 2003

AbstractThe multicomponent domino Knoevenagel hetero‐DielsAlder hydrogenation process of N‐[(benzyloxy)carbonyl(Cbz)‐protected amino aldehydes with N,N‐dimethylbarbituric acid and the trimethylsilyl enol ethers 1–3 leads to the formation of the substituted pyrrolidines 12–15. Under the same conditions, reaction of the trimethylsilyl enol ether 4, obtained from acetophenone, gave the primary amines 18a,b probably due to a hydrogenolytic cleavage of the intermediately formed pyrrolidines. The zwitterionic products were obtained in high purity simply by precipitation with Et2O.
Study of Unusually High Rotational Barriers about SN Bonds in Nonafluorobutane‐1‐sulfonamides: The Electronic Nature of the Torsional Effect
Authors: Lyapkalo Ilya M. , Reissig Hans‐Ulrich , Schäfer Andreas , Wagner Armin 
Published: January 2003

AbstractSlow rotation about the SN bond in N,N‐disubstituted nonafluorobutane‐1‐sulfonamides 1 can easily be detected by NMR measurements at room temperature. This effect causes magnetic nonequivalence of otherwise identical geminal substituents in symmetrical staggered ground‐state conformation A. The torsional barriers determined (62–71 kJ⋅mol−1) proved to be the highest ever observed for sulfonamide moieties. They are comparable to the values routinely measured for carboxylic acid amides or carbamates. The restricted rotation is interpreted as result (nNdS)‐π and of nNσ interactions, which develop substantial S,N double‐bond character in sulfonamides 1. The S,N binding interaction is increased by the highly electron‐withdrawing effect of the perfluorobutyl group. The anticipated symmetry of the ground‐state conformation A and the considerable shortening of the SN bond (1.59 Å) compared to the mean value in sulfonamides (1.63 Å) are confirmed by single‐crystal X‐ray study of N,N‐dibenzylnonafluorobutane‐1‐sulfonamide (1c).
New Results on the Stereoselective Alkylations of Malic Acid Derivatives Supported by Molecular Modeling
Authors: Sefkow Michael , Koch Andreas , Kleinpeter Erich 
Published: January 2003

AbstractThe stereoselectivity of the alkylation of dialkyl malates is dependent on steric hindrance of both ester alkyl groups. It was found that the two alkyl groups have opposite effects on diastereoselectivity. Increased steric hindrance at the C(1) carboxy group increases the anti‐selectivity, whereas increased steric hindrance at the C(4) carboxy group decreases it. The results are explained by comparing the structures of the enolates, which were obtained by molecular modeling. Alkylation at C(4′) of dioxolanones, derived from benzyl‐substituted malic acids, with an additional stereogenic center on the side chain is dependent on the stereogenic centers of the ring acetal and of the side chain. Alkylation at low temperatures occurs only with cis‐dioxolanones having an (R)‐configured side‐chain stereogenic center. The corresponding trans‐dioxolanone and the cis‐dioxolanone with a (S)‐configured side‐chain stereogenic center were recovered unchanged. A rationale is presented with models of monolithiated dioxolanones obtained by ab initio calculations.
Automated Solid‐Phase Synthesis and Structural Investigation of β‐Peptidosulfonamides and β‐Peptidosulfonamide/β‐Peptide Hybrids: β‐Peptidosulfonamide and β‐Peptide Foldamers are Two of a Different Kind
Authors: de Jong Remco , Rijkers Dirk T. S. , Liskamp Rob M. J. 
Published: January 2003

AbstractFmoc‐protected β‐aminoethane sulfonylchlorides can be employed for efficient automated solid phase synthesis of β‐peptidosulfonamides and β‐peptidosulfonamide/β‐peptide hybrids containing one or more β‐peptidosulfonamide residues. Thus, Fmoc‐protected β‐aminoethane sulfonylchlorides 5a–c led to the hexa‐β‐peptidosulfonamide 9 and the nona‐β‐peptidosulfonamide 10. In addition, the β‐peptidosulfonamide/β‐peptide hybrids 13 and 16, consisting of six and nine β‐residues, respectively, and containing a single β‐peptidosulfonamide unit in the middle, as well as the peptidosulfonamide/β‐peptide hybrid 15 with nine β‐residues, including an N‐terminal β‐peptidosulfonamide residue, were synthesized by automated solid‐phase synthesis. Both CD and NMR spectroscopic measurements did not indicate any helical secondary structure for 9 and 10. As was shown by CD‐measurements, the β‐peptidosulfonamide residue in the hybrids 13, 15, and 16 acts as a ‘helix breaker', especially when located in the middle of the hybrid chain (13 and 16), but, although to a lesser extent, also at the N‐terminus.
Trimetaphosphate‐Induced Addition of Aspartic Acid to Oligo(glutamic acid)s
Authors: Hill Aubrey , Orgel Leslie E. 
Published: January 2003

AbstractWhen a solution containing 0.01M decaglutamic acid, 0.1–1.0M aspartic acid, 1.0M MgCl2, and 0.5M sodium trimetaphosphate is allowed to stand at temperatures in the range 0–50°, addition products containing up to ten aspartic acid residues are formed. Addition occurs to the side‐chain carboxy moieties, not to the terminal amine of the decaglutamic acid. A number of other amino acids including glutamic acid, glycine, and histidine fail to react with decaglutamic acid under the same conditions. We believe that the activation of aspartic acid leads to the formation of a cyclic anhydride that is the key intermediate in the reaction.