bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow Rate Dependence of Ventilation
Authors: Mathis DE 
Published: July 2016

Abstract
A quantitative model describing the effects of puffing conditions on the level of filter ventilation was developed and evaluated. The development of the model was based on a quadratic flow-pressure drop relationship which was validated with experimental measurements for numerous plug wraps, tipping papers, and combinations of the two. This relationship was used to derive an equation describing the level of filter ventilation as a function of the flow rate of air exiting the filter. This equation was shown to accurately predict the measured ventilations of six brands of commercial cigarettes over a range of continuous flow rates. The instantaneous ventilation values predicted by the equation were utilized to model ventilation during a puff by integrating the equation with respect to flow rate over the duration of the puff. This method for predicting the effects of specific puffing conditions on ventilation was demonstrated for sinusoidally shaped puffs spanning a wide range of volume and duration. Finally, the effects on the flow dependence of ventilation of different combinations of plug wrap and tipping papers were described qualitatively based on experimental measurements of paper flow-pressure drop linearity.
Tolerance of Tobacco (Nicotianatabacum and N. rustica) to High Rates of Lead Application to the Soil
Authors: Veresoglou DS , Sakellariadis SD , Gerakis PA 
Published: July 2016

Abstract
Eight genetically diverse tobacco types (Tsebelia of Agrinion, Samsun, Basma, Kabakulak, Burley, Virginia and Havana, belonging to Nicotianatabacum, and Brasilia belonging to N. rustica) were grown in pots in the greenhouse where lead acetate had been added to the soil at the rates of 0, 0.1, 1.0 and 10.0 g Pb/kg soil. In the field, 20 g Pb/m2 in two forms (nitrate and acetate) were applied to Burley and Kabakulak types. The greenhouse experiment showed that only the highest rate of lead addition to the soil reduced the leaf yield significantly. The higher yielding types (Havana and Samsun) were found to be the least tolerant, while Brasilia was the most tolerant. At all levels of lead addition to the soil the lead concentration in leaf was found to be highest in the first of the three harvests which were made. The relationship between log (lead level in the soil) and log (leaf lead concentration) seemed exponential. Although control treatments in the field and the greenhouse experiment showed comparable leaf lead concentrations, leaf lead concentrations at 20 g Pb/m2 in the field experiment were found to be higher than those at 1.0 g/kg soil in the greenhouse experiment.
Isolation and Identification of the Wax Esters from the Cuticular Waxes of Green Tobacco Leaf
Authors: Arrendale RF , Severson RF , Chortyk OT , Stephenson MG 
Published: July 2016

Abstract
Recent studies in our laboratory on the cuticular chemicals of green tobacco leaf have revealed the presence of wax esters, composed of fatty acids bound to fatty alcohols. Cuticular components of young green NC 2326 tobacco leaves were removed with methylene chloride, and partitioned between hexane and 80 % MeOH-H2O. The hexane-soluble fraction, which contained wax esters, paraffinic hydrocarbons, and fatty alcohols, was separated by silicic acid column chromatography, and the resulting wax ester fraction was further purified by lipophilic gel chromatography. Initial analyses of the wax ester fraction by capillary gas chromatography [GC] and capillary GC / MS, on a short fused silica [FS] SE-54 capillary column, indicated the presence of C30 - C52 wax esters. Application of the cold on-column injection technique and use of immobilized stationary phase, FS SE-54 capillary columns greatly improved the GC separation of the complex wax ester fraction and permitted the identification of individual wax ester isomers. Identification of wax ester isomers by GC/MS relied upon the presence of a molecular ion and ions characteristic of the acid and alcohol moieties. For the acid portion, these ions included the acid MW + 1 a.m.u. and MW - 17 a.m.u. ions, while for the alcohol, they were the alcohol MW - 18 a.m.u. and MW + 27 a.m.u. ions. Saponification of the wax ester fraction and subsequent analyses of the alcohols (as trimethylsilyl ethers) and acids (as methyl esters) revealed extensive iso- and anteiso-methyl branching of the acid moieties. The wax ester isomers with iso- and anteiso- methyl-branched acid moieties were separated from each other and from the normal straight-chain isomers by capillary GC and were identified by GC/MS, based upon characteristic ions resulting from the losses of the iso-branched (MW - 43 a.m.u.) and anteiso-branched (MW - 57 a.m.u.) groups from the molecular ion and from the acid moiety. One hundred and seventy individual wax esters were identified.
Application of Fourier Transform Infra-red Evolved Gas Analysis (FT-IR-EGA) to the Study of Tobacco Curing
Authors: Fenner RA , Lyons-Hart J , Lephardt JO , Teng DM 
Published: July 2016

Abstract
FT-IR evolved gas analysis, a non-isothermal pyrolysis technique, is used to probe the changes in tobacco leaf composition which occur during flue- and air-curing. A unique perspective of major enzymatic processes and their dependencies on curing method is obtained through simultaneous detection of multiple pyrolytic products and three-dimensional presentation of the product evolution profiles. The conversion of starch to sugars, proteins to amino acids, and the relationships between these processes are explored.
Puff Volume Measurement as affected by Temperature with Various Cigarette Types and Modes of Smoking (an in vitro study)
Authors: Guyatt AR , Baldry AG 
Published: July 2016

Abstract
An in vitro evaluation was made of the measurement of puffing behaviour using an orifice-plate cigarette holder. Four brands of cigarettes were compared ranging in tar yield from 4 to 16 mg, and each was studied with two puff profiles, the “early triangle” and the “square wave” pattern. Two flow rates were used for each profile giving maximum flows of 25.7 and 37.0 ml s-1(early triangle) and 12.0 and 36.7 (square wave), respectively, and four puff volumes, i.e. 15, 40, 65, and 90 ml for each profile/flow combination. Forty-eight cigarettes of each type were smoked (three for each profile/flow/volume combination). The studies emphasize the need for careful calibration of the alinear flow system and the value of reference volume standards. When calibrated with air, volume measurements on smoke at ambient temperature were overestimated by an average of 1.4 %. An average overestimation of 1.2 % was seen per 1°C rise in temperature. This rise in temperature occurred in the last few puffs, and was mainly influenced by the puff volume. There was much less difference when subdividing the data according to cigarette type, the early triangle or square wave profiles, or the two flow rates. With puff volumes of 15 ml there was virtually no temperature rise, and except at 90 ml the effect was only important in the last 20 % of the smoking period.
Evaluation of Selected Steroids as Chemical Markers of Past or Presently Occurring Fungal Infections on Tobacco
Authors: Bindler GN , Piade JJ , Schulthess D 
Published: July 2016

Abstract
Three fungal strains isolated from tobacco were cultured on tobacco water extracts. In these cultures, the mycelium weight was shown to be correlated with the concentration of a steroid, ergosta-5,7,22-trien-3ss-ol [ergosterol]. This steroid is not a tobacco constituent, but tobacco samples where mold or yeast infections had occurred exhibited significant amounts of it. A method is proposed to quantify ergosterol in tobacco samples by reverse-phase high-performance liquid chromatography (HPLC) with UV detection at 282 nm. 7-Dehydrocholesterol can be used as internal standard. When found in a tobacco sample, the ergosterol concentration exhibits a good correlation with that of another related steroid, ergosta-4,6,8(14),22-tetraen-3-one [ETO], for which an HPLC quantification method in tobacco is proposed. Because it is highly fluorescent, ETO is also amenable to a sensitive and quick determination by thin-layer chromatography (TLC). Once produced on tobacco, ergosterol concentration remains stable through storage under normal conditions, and even primary processing does not alter it appreciably. Possible applications of ergosterol analysis to the detection of fungal infections or the monitoring of fungal growth on tobacco are outlined. In addition, TLC estimation of the ETO concentration in a sample may constitute a convenient and fast screening method for fungal infections.
Determination of Particulate Matter and Carbon Oxides in Sidestream Smoke
Authors: Kaneki K , Masuo Y , Okada T 
Published: July 2016

Abstract
An investigation was performed to determine optimum conditions for the generation and collection of particulate matter and carbon oxides in sidestream smoke with a cylindrical chamber of 80 mm internal diameter. The most adequate conditions were found to be 50 cm distance between the burning cone and the Cambridge filter pad and 10 l/ min air flow rate through the chamber. Under these conditions, the static burn rate was virtually the same as that without the chamber and almost constant values for condensate were obtained by replicate measurements. Furthermore, the concentration of carbon monoxide delivered to a room could be estimated by this method. But, it was not possible to estimate the concentration of smoke particles in a room by use of sidestream measurements.
Effect of Chemical Constituents on the Formation Rate of Carbon Monoxide in Bright Tobacco
Authors: Yamamoto T , Suga Y , Kaneki K , Kaneko H 
Published: July 2016

Abstract
From cigarettes made of different bright tobaccos but with a constant fractional volume, the following results were obtained. The rate of formation of CO was a more influential factor determining the amount of CO in mainstream smoke than the weight loss of the cigarette during puffs. From a stepwise multiple regression analysis it was found that the rate of formation of CO was mainly dependent on the potassium content of the tobacco and could be estimated from the amounts of potassium, total carbon, and lignin. The rate of formation of CO increased with a rise in combustion temperature, which in turn rose as the potassium content of the tobacco decreased.
Growth and Development of the Main Greek Oriental Tobacco Cultivars
Authors: Barthakur NN , Arnold NP 
Published: July 2016

Abstract
A microwave generator and a closed-circuit wind tunnel were used to study thermoregulatory responses of tobacco leaf. Heating and cooling curves at various wind velocities showed the maximum reduction of steady-state temperature occurred at 10 cm / s. Wind gusts of high intermittency were very effective in transferring heat from leaf tissue; gust interval and dynamic equilibrium leaf temperature were found to be linearly related. Thermal-time constant and half-cooling time of a tobacco leaf were determined as a function of wind velocity under the conditions of the Newtonian law of cooling. It was determined that transpirational cooling of tobacco leaf in total darkness could occur if leaf temperature was raised above 40°C. This study confirmed that microwaves can be effectively used to study heat exchanges of flue-cured tobacco leaves in vivo under both continuous and fluctuating wind conditions.
The Chemical Control of Tobacco Black Root Rot
Authors: Delon R , Pululu MN 
Published: July 2016

Abstract
With the development of flue-cured and Burley tobacco culture in France, black root rot, caused by Chalaraelegans (Thielaviopsisbasicola), is becoming a problem. Since 1981 the Bergerac Tobacco Institute has studied the efficacy of new endotherapeutic fungicides of the triazole family. Among these, triadimenol was found to be the most effective. The treatment method consists of spraying tobacco plants with a triadimenolsolution 48 to 72 hours before transplanting. This method appears to be an economic and efficient means to control tobacco black root rot in the field. Treatment of young tobacco plants with triadimenol strongly stimulates rhizogenesis and this favours strengthening of the tobacco plants in the field.
Physiology and Biochemistry of the Tabacco Plant3. Physiological Malfunctions: Environment - Physiologie und Biochemie der Tabakpflanze: 3. PhysiologischeStörungen: Umwelteinflüsse
Authors: Tso TC , Bush LP 
Published: July 2016

Abstract
Environmental, biochemical and genetic abnormalities can induce physiological disorder in tobacco. Energy conversion results in production of many air pollutants including ozone which causes weather fleck. High incidence of weather fleck results in earlier flowering, lower yields and lower total alkaloids. More mature leaves are more tolerant to ozone damage than younger leaves. Tolerance to ozone is determined by genetic makeup of the shoot and abaxial stomata. plant damage from ozone or sulfur dioxide is enhanced by the presence of the other pollutant. Frenching is the formation of progressively narrower apical leaves. The cause of frenching is not known but the substance(s) appears to be leached from soils, similar to thallium induced chlorosis and narrow leaves, most active in soil above 35°C, and altering amino acid metabolism in the plant. Genetic tumours form on certain Nicotiana hybrids. These are not of economic importance to N. tabacum production but may be significant as interspecific hybridization is used to improve commercial tobaccos. Tumour formation appears to be controlled by genes on the chromosomes and show conventional segregation, linkage and mutation.
Tobacco Leaf Protein: II. Genetic and Fractionation Approaches to Improving Tobacco Leaf Protein Production
Authors: De Jong DW , Pittarelli G 
Published: July 2016

Abstract
Tobacco variety T. I. 401 was evaluated for seasonal leaf protein yields and crossbred with other genotypes to determine whether leaf protein yield was a genetically transmissible trait. Relatively high leaf protein yields associated with later maturity were observed in preliminary trials but additional crossbreeding and selection is deemed necessary to achieve stable integration of improved leaf protein yields and desirable agronomic performance. Chromatographic and electrophoretic analyses demonstrated that high leaf protein yield of T. I. 401 was not associated with a particular protein fraction but rather was a general phenomenon affecting all major protein classes. Besides examining genetic factors for improving leaf protein yields, two mechanical improvements in leaf protein fractionation technology were introduced into the process. A mild acidification step (to pH 5.5) with a subsequent moderate heat treatment (50°C) resulted in a green coagulum which was readily removed by brief low speed centrifugation without substantial loss of the fraction containing soluble protein which precipitates as a white pellet when heated to 80°C. Hollow-fiber membrane technology was also investigated as a means of producing a purified concentrate with high levels of undegraded protein. The membrane system tested was relatively efficient and greatly improved the quality of the Protein product.
Relative Positions of the Thermal Convection Column and Smoke Plume Generated from a Smoldering Cigarette
Authors: McRae DD , Jenkins RW 
Published: July 2016

Abstract
The relative positions of the thermal convection column and the smoke plume from a variety of smoldering cigarettes were measured using a combination of schlieren and visual optical systems. The schlieren technique is an optical method used to observe refractive index gradients in gases and other clear media. The refractive index gradients can be caused by variations in pressure, composition or temperature. The convection column of heated air and combustion gases rising from a cigarette coal was observed with a two mirror schlieren system. A video camera was used as the observing device rather than the usual photographic camera. A second video camera was arranged to view the smoke plume rising from the coal region. The two video images were combined with a video special effects generator and were viewed on a single monitor. The behaviour and relative positions of both columns were thus observed in real time with two non-invasive optical methods. The schlieren images of the convection column were compared to those of model systems such as a heated cylinder and a small flame. Results for experimental cigarettes with paper porosities of 12 cm/min to 48 cm/min (Coresta) during smolder showed that the thermal convection column was centered 2 mm to 3 mm in front of the paper char line directly over the hottest part of the coal as determined by infra-red imaging. The smoke plume was centered 2 mm behind the paper char line and the position did not change with paper porosity. Results for experimental cigarettes made with a commercially available low sidestream paper showed that the position of the convection column did not change. However, the position of the smoke plume changed considerably. In addition to being markedly decreased in visibility, the plume now appeared to be centered directly over the paper char line. This change in position provides a valuable insight into the mechanism of smoke reduction. The low sidestream papers seem to work by preventing the escape of smoke forming condensibles through the paper behind the paper char line. The condensibles are therefore forced to escape at the paper char line and undergo increased combustion and pyrolysis. As a result, some are converted to lower molecular weight materials and are unable to condense as readily to form the smoke. In addition, the remaining condensibles are released into a hotter and faster rising gas stream. This serves to reduce smoke formation by suppressing condensation and increasing dilution.
The Influence of Different Filter Parameters on the Semivolatile Composition of Mainstream Smoke
Authors: Formella K , Braumann T , Elmenhorst H 
Published: July 2016

Abstract
The semivolatile fraction of cigarette smoke contains the most important aroma and taste compounds which contribute to the smoker's enjoyment. Obviously, the semivolatile composition is strongly affected by cigarette filters and consequently by the material which is used for filter manufacturing. We have studied the effect of cellulose acetate and polypropylene as filter material on the smoke semivolatiles. Further, the effect of other parameters like pressure drop and the use of additives has been investigated. Smoke condensate was collected on a Cambridge filter pad, the semivolatiles were evaporated using a headspace apparatus and subsequently collected in a cold trap. Semivolatile analyses were performed by high-resolution GC/MS. The cellulose acetate filter, due to its polar structure, selectively retains polar compounds such as phenols and furans while the non-polar polypropylene filter shows a non-selective retention behaviour. The addition to polypropylene filters of a polar compound such as triacetin, which is used as plasticiser in the manufacturing of cellulose acetate filters, does not affect the retention behaviour towards the semivolatiles.
Determination of Free and Bound Maleic Hydrazide Residues in Tobacco by High Performance Liquid Chromatography
Authors: Dattilo BS , Gallo S , Lionetti G , Rossi SG 
Published: July 2016

Abstract
A new method is described for the qualitative and quantitative determination of both free and bound maleic hydrazide residues in tobacco leaves and cigarette filler by high performance liquid chromatography. Analyses were carried out by hydrolyzing samples of ground tobacco with 4 N hydrochloric acid for 40 minutes under reflux followed by sample chromatography, running isocratic elutions with a dilute solution of phosphoric acid. The quantitative determination of maleic hydrazide was performed by light absorption at 320 nm, by the calibration curve method. Recoveries of maleic hydrazide added to tobacco samples were greater than 90 %. The detection limit of the method, determined on ground tobacco leaves, was at least 5 ppm. The results obtained by this procedure and by the ISO standard method no. 4876 are in good accordance.
Determination of Residues of Eight Synthetic Pyrethroids in Tobacco by Capillary Gas Chromatography
Authors: Dattilo BS , Gallo S , Lionetti G 
Published: July 2016

Abstract
A method was developed for the simultaneous determination of the residues of the following eight synthetic pyrethroids and their isomers in tobacco: tetramethrin, permethrin, cyfluthrin, cypermethrin, alfamethrin, flucythrinate, fluvalinate and deltamethrin. The pesticides were extracted from ground tobacco by means of acetone:water 9:1 for 5 hours. The extract was diluted with water and partitioned into n-hexane. The organic phase was concentrated to about 1 ml and then purified by a Florisil-SPE column. The gas-chromatographic analyses were run with a gas-chromatograph Carlo Erba Series Mega HRGC 5300 equipped with a capillary column (stationary phase OV-1 - 0.10-0.15 µm film thickness, 25 m long) and a 63Ni electron-capture detector. Two different injection ports were used: split-splitless and cold split-splitless, working both with isothermal and programmed temperatures. Both the limit of detection and the limit of determination were estimated for each compound. Recoveries from fortified samples at level of 1 µgKg-1 are reported.
Human Smoking Behaviour in Comparison with Machine Smoking Methods: A Summary of the Five Papers Presented at the 1995 Meeting of the CORESTA Smoke and Technology Groups in Vienna
Authors: Eberhardt HJ , Scherer G 
Published: July 2016

Abstract
During the last months there have been extensive discussions, particularly in the United States, whether and to what extent data obtained by machine smoking using standardized methods (e.g. ISO, FTC, Coresta) permit conclusions about the actual uptake of smoke constituents (nicotine, condensate, etc.) by a smoker. This topic was a major focus of interest at the meeting of the Coresta Smoke and Technology Group in Vienna from 10th to 14th September 1995. A total of five studies were presented, four of which compared smoke yields obtained by standard machine smoking with actual yields obtained by human smoking. The fifth study investigated the effect of alternative puffing regimens and filter vent blocking on “tar” and nicotine yields of cigarettes. This paper summarizes the essential findings of the five studies.
Trends in Tobacco Leaf Usability
Authors: Campbell JS 
Published: July 2016

Abstract
The farmers and the buyers are partners in the production and purchase of usable tobacco leaf for manufacture into products acceptable to the consumer. The blend in these products and their ultimate sales price in the market place alters over time. Both parties must continually be aware of, and react to, these changes, if they are to stay in business. The principles of leaf purchase with regard to selection of ideal subjective looks, particularly emphasizing colour, maturity and plant position, will not be radically changed, but they must be coupled with acceptable, objective chemical contents to ensure subsequent, accurate product blending and favourable smoking properties. High technology in cigarette manufacture also demands that the threshed product, after green leaf processing, notably particle size, objectionable stem, and stem in lamina, together with packing moisture and minimal foreign matter, must meet strict specifications. The growing, curing, marketing, and purchase of leaf, together with its green leaf processing and cigarette manufacture, have all become more objective in definition. Usability, in relation to all these factors, is therefore what is attractive to the buyer/manufacturer and ultimately to the consumer, but the actual inclusion of leaf in a particular product is also related to its price. Usability and price play a major role in leaf selection and these are discussed.