bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Pressure Drop Measurements for Estimating Ventilation and Paper Porosity
Authors: Keith C. H. 
Published: July 2016

Abstract
Equations for calculating dilutions in vented cigarette filters and tobacco columns from pressure drop measurements are derived. These calculated dilutions are found to agree closely with those directly measured for a variety of commercial and experimental cigarettes wrapped with perforated and porous tipping and with different cigarette papers. The effect of hole placement on dilution and cigarette pressure is estimated. The effects of filter dilution on particulate matter, condensate and carbon monoxide delivery are discussed. A method for measuring filter dilution during smoking by means of pressure drop measurements is outlined and results for a typical vented filter cigarette are shown and discussed. The use of pressure drop measurements for estimating paper porosity and amount of dilution in the tobacco column on finished cigarettes is out-lined. The dilution obtained by this method was generally higher compared to the results found by a model based on a capillary flow regime, which suggests that flow through ordinary cigarette paper is a combination of capillary and orifice flow. The non-destructive nature and simplicity of pressure drop measurements make this method of measuring dilution useful in quality control of cigarette production.
Studies on the Natural Smouldering of Cigarettes: III. Determination of the Thermal Properties of Tobacco Shreds Packed in Columns
Authors: Muramatsu Motohiko , Umemura Setsuko , Okada Takashi 
Published: July 2016

Abstract
The values of effective thermal conductivity, specific heat and thermal diffusivity of various kinds of tobacco shreds, which are necessary for the solution of heat transfer problems of a smouldering cigarette, were determined. Effective thermal conductivity of tobacco shred packed into simulated cigarette columns was measured by a transient hot-wire method as a function of packing fraction at conditions of 20°C and 60 % relative humidity. Specific heat was measured with the aid of a differential scanning calorimeter (DSC). The thermal diffusivity was obtained from the values of effective thermal conductivity, specific heat and packing density. Effective thermal conductivity increased with increasing packing fraction (1 - e) and was uniformly expressed as a function of the total void fraction (et) inside the column regardless of tobacco types and stalk positions, whereas thermal diffusivity decreased with the packing fraction. At the same packing fraction, bright shreds produced higher values of effective thermal conductivity as well as higher specific heats (although specific heat was independent of the packing fraction) but had lower thermal diffusivity values than Burley and Matsukawa shreds.
Dihydro-γ-pyrones in Tobacco SmokeIdentification of 2,3-Dihydro-5-hydroxy-6-methyl-4H-one in the Smoke of Cigarettes from Burley, Virginia and Oriental Tobacco/Dihydro-γ-pyrone im Tabakrauch: Nachweis von 2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-4-on in Rauch von Cigaretten aus Burley-, Virginia- und Orienttabaken
Authors: Elmenhorst H. , Nicolaus G. 
Published: July 2016

Abstract
2,3-Dihydro-5-hydroxy-6-methyl-4H-pyran-one [I] has been identified as a new cigarette smoke constituent. The concentration of substance I and of the homologous compound 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one [II] - determined in the smoke of Oriental, Virginia and Burley leaf - varies according to the type of tobacco. The amounts of substance I are 26, 20 and 6 µg a cigarette in the smoke of Oriental, Virginia and Burley tobaccos, respectively. For compound II the corresponding figures are 11, 13 and 4 µg a cigarette. Substance I is a new flavour compound which has a caramel odour with fruity overtones. This is undoubtedly important for the aroma of tobacco smoke. However, the presence of dihydro-γ-pyrone I in tobacco smoke is of theoretical interest as well. It is a cyclic enolone and has a structure similar to that of maltol and the cyclopentenolones, which we identified in tobacco smoke some time ago. Based on the similarity of structures we want to put forward the working hypothesis that a majority of the aroma substances in tobacco smoke have the constitution of an alicyclic or O-heterocyclic enolone containing a carbonyl and a C-alkyl (methyl or ethyl) group.
Polyphenol Accumulation in Chlorophyll Mutants of Tobacco under Two Cultural Practices
Authors: Sheen S.J. , DeJong D. W. , Chaplin J. F. 
Published: July 2016

Abstract
Quantitative variation in plastid pigments and polyphenols during leaf growth and after curing have been studied with several chlorophyll-deficient genotypes of tobacco. Under culture for flue-cured tobacco, the chlorophyll-deficient pale-yellow (NC95-Py) and yellow-green (SC58-yg) lines did not differ in polyphenol accumulation from the corresponding normal green recurrent parents NC95 and SC58. A negative correlation was evident between concentrations of polyphenol and chlorophyll. Decrease of the latter during leaf growth was accompanied with a decline of PPO and PRO activities. When the chlorophyll-deficient genotypes were grown under conditions for Burley tobacco, concentrations of chlorophyll and polyphenol maintained a steady level and were positively correlated, while the oxidases tended to increase. Burley 21 contained the lowest amount of polyphenols among the chlorophyll mutants, although the low chlorophyll content of its mature leaves was comparable to that of SC58-yg. Use of cultural practices for flue-cured tobacco caused an accumulation of polyphenols in green leaves. There was a greater loss of soluble polyphenols during air-curing than during flue-curing. Results indicate that the interaction of cultural practices with chlorophyll-deficient genes affects the metabolism of chlorophylls and polyphenols during leaf growth and maturation. Introduction of these genes into tobacco cultivars may provide a means of enhancing uniformity of leaf maturity and modifying certain leaf chemical constituents.
Gas Chromatographic Determination of Pesticide Residues in Plant Material after Clean-up by Gel Chromatography and Mini-silica Gel Column Chromatography. 1st Report: Organochlorine Pesticides in Tobacco and Tobacco Products/Gaschromatographische Bestimmung von Rückständen an Pflanzenbehandlungsmitteln nach Clean-up über Gelchromatographie und Mini-Kieselgel-Säulenchromatographie. 1. Mitteilung: Organochlor-Pflanzenbehandlungsmittel in Tabak und Tabakerzeugnissen
Authors: Specht W. , Tillkes M. 
Published: July 2016

Abstract
This report contains the first description of a method for pesticide residue determination using automated gel permeation chromatographic clean-up. The example of organochlorine pesticides in tobacco and tobacco products has been taken here to illustrate this method. Water is added to the sample which is then extracted with acetone such that the ratio of the volume of acetone used to the total volume of water is 2 :1. The key step in the method is the efficient removal of co-extracted plant constituents, by gel permeation chromatography on a polystyrene gel (Bio-Beads S-X3). The pesticides are recovered, without loss, in 65 ml of eluate. This eluate is further purified by very simple chromatography on a 1 g column of deactivated silica gel, two 10 ml fractions being collected. No interfering substances are present m these fractions and the pesticides may be identified and quantified without ambiguity. The limit of detection was, for example, for α-BHC 0.002 mg/kg and for p,p'-DDT 0.02 mg/kg. The recoveries of pesticides from spiked samples lay between 90 and 100 %. The method is also suitable for the extraction and purification of polar pesticides so that with a single sample processing a large number of different pesticides may be determined by GLC. This will be described in a forthcoming paper.
The Effect of Filter Ventilation on the Yield and Composition of Mainstream and Sidestream Smokes
Authors: Browne C. L. , Keith C. H. , Allen R. E. 
Published: July 2016

AbstractApparatus and procedures were developed to measure condensate, nicotine, water, carbon monoxide and carbon dioxide in mainstream and sidestream smoke. These were used to determine the effect of air dilution through filter ventilation on mainstream and sidestream smoke composition. It was found that there is a gradual transition from 'puffing combustion to smoldering combustion as the amount of diluting air entering the system increases. This is directly related to the decreased puff volume at the cone and decreased amount of tobacco consumed per puff. On a per· gram of tobacco consumed basis, sidestream combustion product formation is not changed but the amounts of carbon monoxide and water in the mainstream are decreased, as ventilation increases.
Residues of Ethoprop and Disulfoton in Soils and Flue-cured Tobacco
Authors: Leidy R. B. , Sheets T.J. 
Published: July 2016

AbstractSoil samples collected approximately 21 days after pretransplant applications of ethoprop to flue-cured tobacco land contained residues averaging 0.54 and 1.13 ppm, respectively, for the 6.7 and 13.4 kg/ha rates. In contrast total residues of disulfoton (disulfoton plus three metabolites) averaged 0.28 and 0.54 ppm at 3.4 and 6.7 kg/ha rates. Concentrations of both compounds decreased with time at each of two locations. Residue levels of ethoprop in the first harvest of flue-cured tobacco from the Central Crops Research Station (Clayton, North Carolina) were 0.04, 0.02, and 0.08 ppm; from the Upper Piedmont Research Station (Reidsville, North Carolina), residues were 0.20, 0.16, and 0.27 ppm, respectively, for rates of 6.7, 6.7 combination (with disulfoton), and 13.4 kg/ha. Residues declined in succeeding harvests. Total residues of disulfoton plus three metabolites in the first sample of tobacco harvested from Central Crops averaged 2.52 and 1.89 ppm; and from Upper Piedmont residues averaged 10.24 and 6.50 ppm, respectively, for rates of 3.4 and 6.7 kg/ha. The residues declined in succeeding harvest and were 0.14 ppm or less by the fourth harvest at Central Crops and 0.08 ppm or less by the fifth harvest at Upper Piedmont.
Automatic Microwave Moisture Meter
Authors: Thomas C. F. , Bourlas M. C. , Laszlo T. S. , Magin D. F. 
Published: July 2016

AbstractA method for determining the moisture content of tobacco based upon microwave heating has been conceived and developed. At the conditions and with the sample size selected, the method satisfies the requirements of the tobacco industry for rapid accurate moisture determinations during the processing of tobacco. It has thus been shown to be a viable alternative to moisture analysis by Karl Fischer titration and the conventional oven drying procedure. It has also been shown that the calculated percent weight loss in the microwave instrument coincides with the actual water content with negligible loss of volatiles other than water. This is in sharp contrast to the results obtained in oven drying the tobacco. The concepts employed in the moisture meter are not limited to tobacco as a sample. It may be useful for moisture determinations on a variety of previously difficult or time-consuming to analyse materials such as grain, paper or meat. It is envisioned in the future as a generally acceptable method for the measurement of the moisture content of tobacco
Description of a Continuous-Smoking Inhalation Machine for Exposing Small Animals to Tobacco Smoke
Authors: Baumgartner H. , Coggins C. R. E. 
Published: July 2016

AbstractThe fuller understanding of the biological responses of rodents inhaling cigarette smoke has been hindered, in part, by the inability to dose simultaneously a large number of animals with satisfactory reproducibility. This paper describes an inhalation machine which allows the simultaneous exposure of up to 72 animals to a continuous flow of freshly diluted cigarette smoke
The Chemical Evaluation of a Continuous-Smoking Inhalation Machine
Authors: Briggs C. D. , McCready J. , Schweizer A. 
Published: July 2016

AbstractThe paper describes experiments which have been used to evaluate an inhalation smoking machine for small animals. Deliveries of undiluted and diluted smoke from this machine have been compared to reference data obtained from an analytical smoking machine. Deliveries of smoke immediately behind the smoke pump were lower than those from the analytical machine, largely due to differences in puff number (created largely by differences in paper regression between puffs) and deposition. When these factors were accounted for, deliveries from the two machines compared favourably. However, deliveries of diluted smoke, although apparently independent of dilution level, were somewhat lower than analytical deliveries. Thus the inhalation machine delivered about 65 % of the particulate matter, 80 % of the nicotine and 85 % of the carbon monoxide delivered by the analytical machine on a per puff basis (for 100 % tobacco or 50 % tobacco : 50 % Cytrel). A 100 % Cytrel cigarette delivered 80 % of the particulate matter and 90 % of the carbon monoxide (no nicotine). After accounting for deposition, consistent deliveries of about 85 % were achieved for all three constituents in all-tobacco cigarettes, while corrected deliveries for 100 % Cytrel cigarettes were about 90 % for both particulate matter and carbon monoxide. Deliveries of hydrogen cyanide and total volatile aldehydes in both samples were about 85 % of those achieved on an analytical machine
The use of pressure drop measurements for estimating ventilation and paper porosity/Verwendung von Zugwiderstandsmesswerten zur Abschätzung von Ventilation und Papierporosität
Authors: Keith C. H. 
Published: July 2016

AbstractIn our recent article on the above-mentioned topic, the derivation of the pressure drop equations was based on the first approximation that diluting air flow is constant over the length of a filter or tobacco column. While this is a reasonable approximation for filters and tobacco columns with low levels of dilution, it appears to give inaccurate results for tobacco columns with high levels of dilution, as was pointed out by Cummings.
Variation of the Gas Formation Regions within a Cigarette Combustion Coal during the Smoking Cycle
Authors: Baker Richard R 
Published: July 2016

AbstractInternal contour distributions for gas temperatures and for the concentrations of carbon monoxide, carbon dioxide, hydrogen, propane and oxygen have been determined at successive times before, during and after a puff of a burning cigarette. The cigarette was smoked in an atmosphere of 21 % (v/v) oxygen in argon. The gases were withdrawn from the cigarette through a small sampling probe and filtration unit, and analysed using a quadrupole mass spectrometer. The contour distributions show that the gas formation and transmission processes occurring in the coal, and their variation during the smoking regime, are complex. The interior of the coal is almost entirely devoid of oxygen. The consumption of oxygen is so rapid that the position of its major influx into the coal, near the paper burn line, cannot be seen on the contour diagrams during a puff. However, the oxygen influx during the puff leaves burnt-out channels in the coal which become evident at later stages in the smoking cycle. When the puff ends, the product formation/transfer balance is interrupted, resulting in a local build-up of the product in its formation region. This local build-up reaches a maximum at 0.5-1.0 seconds after the end of the puff, after which time diffusion processes deplete the level. During the static smoulder period, distinct high and low temperature regions for the formation of carbon monoxide and dioxide are not evident inside the coal. However, towards the latter half of the puff, a distinct carbon dioxide formation region starts to appear behind the completely oxygen-deficient region. Application of the pyrolysis computer model, developed previously, confirms that this second region is a thermal decomposition region, and shows that such a region for carbon monoxide is not resolved from the combustion region.
Isolation and Identification of Phenolic Acids from Tobacco Leaf
Authors: Snook M. E. , Fortson P. J. , Chortyk O. T. 
Published: July 2016

AbstractA new chromatographic method utilizing the hydrogen bonding properties of Sephadex LH-20 gel in methanol / chloroform, was developed for the isolation of phenolic acids. This method was applied to the characterization of phenolic acids in flue-cured tobacco. Gel chromatography successfully isolated and concentrated the phenolic acids from other acidic substances and allowed identification and quantitation of these compounds by GC and GC-MS, as their trimethylsilyl derivatives. Compounds identified included: cis- and trans-isomers of p-coumaric, ferulic, caffeic, and sinapic acids; o-, m-, and p-hydroxybenzoic acids; o-hydroxyphenylacetic acid; 2,5- and 3,4-dihydroxybenzoic acids; and 2,3-, 2,5- and 3,4-dihydroxybenzaldehydes. Caffeic acid was the major compound, probably arising from the degradation of the chlorogenic acid of leaf. Aliphatic acids having two or more carboxyl groups were also isolated and included the following: malonic, succinic, fumaric, malic, and citric acids. A dihydroxycinnamaldehyde and a dihydroxynaphthoic acid are reported in tobacco leaf for the first time.
Mass Spectra of Tobacco Alkaloid - Derived Nitrosamines, their Metabolites, and Related Compounds
Authors: Hecht Stephen S. , Chen Chi-Hong B. , Young Ruth , Hoffmann Dietrich 
Published: July 2016

Abstract
The mass spectra of the tobacco alkaloid - derived nitrosamines NNN, NNK, NNA, NAB and NAtB and of known mammalian metabolites of NNN and NNK are presented. Mass spectra of synthetic derivatives related to these nitrosamines and their metabolites are also included. These spectra will be useful in studies on the occurrence and metabolism of the tobacco alkaloid - derived nitrosamines and in investigations of other compounds related to the tobacco alkaloids.
Pressure Drop - Flow Relationships in Cigarette Filter Rods and Tobacco Columns
Authors: Keith C. H. 
Published: July 2016

AbstractWith a liquid displacement flow system, pressure drop and flow measurements were performed on filter rods, tobacco columns and multicapillary pressure drop standards. The purpose of these measurements was to determine the relative contributions of laminar or viscous flow, inertial flow, and entry and exit effects to pressure drop. Pressure drops were obtained both by forcing and drawing air through the article. No difference in pressure drop was obtained by either method provided that the flow was the same at a common point in the rod. This specification was necessary because of the change in flow rate due to gas expansion inside the rod. Pressure drop contributions from gas expansion, thermal effects and rod collapse were negligible. From regression equations, the major pressure drop component in all three types of article was viscous flow, ranging from 98 % of the total pressure drop in filter rods to 79 % in tobacco columns. Entry and exit effects were small in both filter rods and tobacco columns but were appreciable and the only other pressure drop contributor in multicapillaries. These measured entry and exit effects in multicapillaries agreed well with those estimated by flow theory. Inertial flow was found to contribute 1.5 % and 19 % of the total pressure drop in filter and tobacco rods, respectively. These contributions are reasonable from flow theory for packed columns.
Detection and Quantitative Determination of Alkylnaphthalenes in Latakia Tobacco/ Nachweis und quantitative Bestimmung von Alkylnaphthalinen in Latakia-Tabak
Authors: Nicolaus G. , Elmenhorst H. 
Published: July 2016

AbstractNaphthalene and alkylnaphthalene were detected qualitatively and quantitatively for the first time in Latakia tobacco. 62 different alkylnaphthalenes were determined by means of GC-MS analysis, 22 of which were exactly allocated structurally by comparing the Kovats retention indices. Besides naphthalene, the following substances were also identified: 1-methylnaphthalene, 2-methylnaphthalene, 1-ethylnaphthalene, 2-ethylnaphthalene, 1-propylnaphthalene, 2-propylnaphthalene, all ten theoretically possible isomers of dimethylnaphthalene, four trimethylnaphthalenes, isobutylnaphthalene and five ethylmethylnaphthalenes. The concentration of the naphthalenes detected in Latakia tobacco is in the region of 1 ppm to 10 ppm, with the focus on 1 ppm to 3 ppm. Alkylnaphthalenes make an important contribution to the aroma of the Latakia tobacco. They clearly modify the burnt aroma of the Latakia phenols to mild, dusty, with earthy undertone.
Simple Correlation and Multiple Regression among Leaf and Smoke Characteristics of Burley Tobaccos
Authors: Tso T.C. , Chaplin J. F. , Adams J. D. , Hoffmann D. 
Published: July 2016

AbstractLeaves from 8 stalk positions from four Burley tobaccos, the cultivars Burley 21, Ky 14 and Ky 12 and one breeding line of low-alkaloid Burley 21 (LA Burley 21), were tested in this study. A total of 116 variables, including leaf and smoke characteristics, were determined by collaborating scientists using established methods. Simple correlations and multiple regressions among selected variables were determined to examine the relationship among these variables. Generally, Burley tobaccos do not differ from bright tobaccos, in that the nitrogenous fractions and combustibility appear to be the major factors affecting nicotine and dry TPM (total particulate matter) delivery as well as other major smoke constituents. Stalk position and varieties also demonstrated significant differences in nicotine and dry TPM delivery. Benzo[a]pyrene content, however, did not show significant differences among these experimental Burley tobaccos or stalk positions.
Accumulation of Soluble Proteins and Nitrogenous Compounds in the Leaf of Bright and Burley Tobaccos during the Growing Season
Authors: Lowe R.H. , Sheen S. J. 
Published: July 2016

AbstractUnder conventional cultural practices for Burley tobacco, the pattern of soluble protein accumulation, namely Fraction I protein (F I protein) and Fraction II protein (F II protein), in bright (NC95) and Burley (Ky14) tobaccos were similar during the growing seasons of 1977 and 1978. Their quantities reached maximal levels around flowering, followed by a gradual decline. However, the loss of F I protein was much more rapid than that of F II protein during leaf maturation. The two-year results revealed that Ky14 contains significantly more F I protein, insoluble proteins, total proteins, free amino acids, total nitrogen, nitrate nitrogen and total alkaloids than NC95, if averaged over the growing season. The latter showed a greater amount of chlorophyll only. There was no difference in F II protein concentration between the two cultivars. On the basis of soluble protein concentration in leaf lamina and a double or quadruple plant population as plant size permits, the estimated yields of soluble proteins in Ky14 at the immature plant stage, about one week before topping, and by harvest time are 888, 470 and 281 kg/ha, respectively. When including both soluble and insoluble proteins, the immature plants of NC95 could yield 1387 kg/ha of protein, in comparison to 1308 kg/ha for Ky14. Multiple harvests of regrowth can further the protein yield per hectare. The present results strongly suggest that tobacco is a potential protein crop for the future.
Rapid Spectrophotometric Analysis of the Chemical Composition of Tobacco: Part 3: Polyphenols
Authors: McClure W.F. , Williamson R.E. 
Published: July 2016

AbstractTwo hundred thirty-eight ground samples of tobacco were scanned with a computerized near-infra-red (NIR) spectrophotometer to study the relationship of NIR spectra to the polyphenol content of the samples. A multiple linear regression model was used to select the most appropriate wavelengths for making the measurements. The equationP = polyphenols in %Di = wavelength in micrometers at which the parameter is measured.