• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.30-38
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• 1996

Meiotic metaphase chromosomes of the testis of two storage insects, tobacco moth (Ephestia elutella H.) and cigarette beetle (Lasioderma serricorne F.) were examined to study their karyotypes. The number of haploid chromosomes of the tobacco moth was 31 and the karyotype was characterized by 29 metacentric and 2 submetacentric chromosomes. The metaphase chromosome length of tobacco moth ranged ca. 1.44-2.11${\mu}{\textrm}{m}$ and the average length was 1, 78${\mu}{\textrm}{m}$. The number of haploid chromosomes of the cigarette beetle at metaphase was 10 and the karyotype was characterized by 8 metacentric and 2 submetacentric chromosomes. The range of metaphase chromosome length of the cigarette beetle was ca. 1.79- 2.39${\mu}{\textrm}{m}$ and the average length 2.09${\mu}{\textrm}{m}$.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.1
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• pp.83-91
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• 1988

The effects of tipping paper permeability and plugwrap porosity on the ventilation and the pressure drop of cigarettes have been studied and the results obtained were as follows. 1. The single and the multiple regression equation to estimate tip ventilation were establised. In the equations, the observed values of the tip ventilation with the varieties the plugwrap porosity were content with them by the single regression equation. 2. As based on the statistical consideration of the above equation, the deviation of the observed tip ventilation versus the tipping paper permeability were higher than them to the plugwrap porosity. 3. The regression equations to calculate pressure drop ratio and the total ventilation rate in filter tip from the tea ventilation were obtained. According to the equation, the observed values of the pressure drop ratio were significantly similar to them calculated. 4. It was found that the equations could be applied to the calculation of the ventilation of cigarettes using the mechanical and micro laser perforation tipping paper as well as the electrically perforated tipping paper of this Study.

• Journal of the Korean Society of Tobacco Science
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• v.16 no.2
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• pp.122-127
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• 1994

Feeding preference of cigarette beetle, Lasioderma sewicorne F., on cured tobacco leaves was investigated to obtain basic information on ecological management of the insect pest in tobacco storage warehouses. About 3, 000-4, 000 adults of the insect were released in a warehouse in which groud tobacco leaves were placed on the bottom and at 3m above the floor level, and numbers of insects attracted were examined. There was no significant difference on feeding preference between the two tobacco varieties, flue-cured(NC82) and air-cured(Br3l) tobacco leaves. However, significant differences were noted in feeding preference between thick and thin leaves and among different quality grades within a tobacco variety. Feeding preferences of cigarette beetle between flue- and air- cured tobacco varieties showed significant differences on the lower position, though there were no differences on the 3m upper position. On the 3m upper position, feeding preferences were different between thick and thin leaves of tobacco varieties, and variety X thickness and variety X thickness equality grades showed statistically significant differences. Significantly higher feeding preference by cigarette beetle adults was observed for the food placed on the 3m upper than on the lower position. There were negative correlations between quality grades of cured tobacco leaves and feeding preference on the lower position, and the regression equation was Y(feeding preference)=4.050-0.683 X (degree).

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.33-39
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• 1998

Survival, growth and reproduction of the cigarette beetle, Lasiodema sewicome F., were studied on flue-cured (NC82), air-cured (Br.21), aromatic (Izmir) tobacco and artificial diet (wheat feed 95% + yeast 5%). Cigarette beetle adults occurred from first generation in the flue-cured and aromatic tobacco, but no adults emerged in air-cured tobacco after the 2nd generations. The head capsule widths of larvae of the cigarette beetles L sewicome F.1 reared on different diets at 2$0^{\circ}C$, $25^{\circ}C$ and 3$0^{\circ}C$ were measured. The head capsule development was slower at 2$0^{\circ}C$ on the same diets than $25^{\circ}C$ and 3$0^{\circ}C$, and slower in the flue-cured and aromatic tobacco than the artificial diet at 2$0^{\circ}C$ and 2S$^{\circ}C$, At $25^{\circ}C$ the larval head capsule developed more rapidly in the aromatic tobacco than the flue-cured tobacco. However, no larval head development was noticed in the air-cured tobacco. The correlation between population densities of cigarette beetle,1 sewicome F., and sugar content of tobacco leaves was positive, but negative in nicotine contents. The regression between densities and sugar content was Y : 22.79 X + 57.29 (r=0.891**), and between nicotine content was Y : -141.31X + 321.40(r=-0.917**).

• Journal of the Korean Society of Tobacco Science
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• v.7 no.2
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• pp.179-188
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• 1985

From the combination of cigarette papers, tipping papers and plug wrapping papers, whose physical properties and effect of cigarette smoke dilution were studied. The result obtained from this study are as follows. Envelop ventilation (Env-V'R) cigarettes used high porous cigarette papers showed less changes of unencapsulated pressure drop VPD) compared to tip ventilation (Tip-VR) cigarettes. Higher cigarette paper porosity increased, more decreased the WD of cigarette by Tip-VR. With cigarette length shortening, the UPD or VR changed a little in Tip-VR cigarette, while changed very much in Env-VR cigarettes. The ratio of nicotine/tar was higher in Env-VB cigarettes than in Tip-VR cigarettes, and CO/nicotine value of the former was lower than those of the later. The effect of Tip-VR cigarettes on the delivery reduction of tar and nicotine was more effective compared to Env-VR cigarettes and the reduction prefer Env-VR cigarettes to Tip-VR cigarettes in CO delivery. From the results investigated above it was noted that each defect appeared in the Tip-VR and the Env-VR cigarettes could be complemented by the combination of them.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.2
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• pp.201-206
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• 2005

In this work, we studied the effects of the moisture contents of cut tobacco on loose end of cigarettes. The loose end of the cigarette groups decreased with the increase of moisture contents of the cut tobacco and especially the loose end of A and C groups decreased to $31\%\;and\;52\%$ with the increase of $1\%$ moisture contents. $A-13.5\%\;and\;B-14.0\%\;and\; C-14.0\%$ moisture samples showed the increase of the weight ratio of cut tobacco over 1.4mm cut length but the decrease under 1.4mm cut length. We concluded that the main reasons were regarded to reduction of small fragment tobaccos caused by increase of moisture contents and exception of air-suction transport of tobaccos to cigarette making machine. In spite of the moisture increase of cut tobaccos under fixed EPD(encapsulated pressure drop), the hardness of Band C sample groups were maintained constantly except A group. This result means that under fixed EPD, the weight of cut tobacco in cigarette rods increases to compensate the reduction of pressure drop by moisture increase of cut tobaccos.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.1-8
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• 2009

This study was conducted to determine the effects of processed tobacco leaves on the development, adult emergence and body weight of the cigarette beetle, Lasioderma serricorne Fabricius) (Coleoptera: Anobiidae) is serious insect pest of tobacco leaves and cigarette during storage. Developmental time, adult emergence rate and adult weight of the cigarette beetle, were evaluated on the cured tobacco and burley tobacco leaves at $30{\pm}1^{\circ}C$ with $70{\pm}5$ % RH under 12L:12D. The developmental time on all of the flue-cured tobacco leaves was about 61 days, but in the only CD3W and CD4TR grade burley tobacco, the developmental times ranged from 70 days to 74 days. Among the flue-cured tobacco leaves, the highest beetle emergence rate was 123 % on the CD3L grade, and the lowest was on the AB4OR grade. Adult body weights of the cigarette beetle reared on flue-cured tobacco were about 2.11~2.46 mg, and on the only CD3W and CD4TR grade burley tobacco were about 1.86~1.96 mg. Among the flue-cured tobacco leaves, the highest adult body weight(2.46 mg) of cigarette beetle was observed on the B1O grade flue-cured tobacco, whereas the lowest adult weight(2.11 mg) was observed on the CD4L grade flue-cured tobacco. The adult weight of cigarette beetle reared on whole meal was 2.04mg.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.167-173
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• 1993

Pirimiphos - methyl was fogged in a tobacco warehouse to determine the proper dose rate, Small wire cages, containing adults and larvae of cigarette beetle (Lasiodema senicorne F.) were put at different altitude in the warehouse of which the holding capacity was about 250m3. At recommended dose rate, 0.4ml/m3(25% ai), it brought about 100% mortality of adults and 98.8% -100% mortality of larvae. When the dose rate was reduced to about half the recommended one, 97.6 and 96.4% mortality could still be obtained against adults and larvae, respectively. The number of the beetles monitored by sex - pheromone trap was greatly reduced after the fogging in the warehouses at 4 geographic places in Korea. When the warehouses were ventilated for one hour immediately after the fogging done for 48 hours, workers could not detected any opposing smell in the warehouses. And panel members responded positively that there was no negative effect on the taste of the cigarettes made of the fogged tobacco. Although the residue of the chemical was detected from the cigarettes in 4 of 5 cases, the residue was 1.1-1.3$\mu\textrm{g}$/20 cigarettes except for one case from which 3.3$\mu\textrm{g}$/20 cigarettes residue was detected. The relatively low residue is about l/450-1/150 of the WHO/FAO tolerant level.

• Journal of the Korean Society of Tobacco Science
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• v.8 no.1
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• pp.3-12
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• 1986

Extensive studies have been made of the effects of freeness and the calcium carbonate on the physical properties of hand-sheets from commercial flax, kenaf and NBKP. As freeness increased, the hand-sheets from the pulps above showed higher retention rate of calcium carbonate, brightness, opacity and tensile strength but lower value of porosity. Among these, the retention rate(46%) showed the highest value In kenaf, the porosity(205 c.u.) in flax, and the opacity(67%) and the tensile strength(2.8kg) in NBKP respectively. Under the constant freeness, retention rate of calcium carbonate in hand-sheets increased until 1.4 times pulp weight was added in flax and kenaf but, in NBKP, decreased from the beginning of 0.8 times with the highest retention rate. Results above led to higher porosity, opacity, brightness but lowered tensile strength. Mixed pulp(Kenaf+ NBKP) showed higher retention rate than each pulp. Pictures of X-ray diffraction and scanning electron microscope demonstrated that both of domestic and foreign calcium carbonates were calcite of spindle form. The brightness of foreign calcium carbonate was higher by 295 than that of domestic one. The average particle size of calcium carbonate was 2.1 U m(domestic), 3.6 U m(foreign).

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.388-397
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• 2020

Objectives: The aim of this study was to assess the association between the use of heated tobacco products (HTP) and suicidal behaviors such as suicidal ideation, suicide planning, and suicide attempts among adolescents in South Korea. Methods: The study used a cross-sectional design. Data was from the 15th Korea Youth Risk Behavior Web-based Survey (KYRBS) performed in 2019 by the Ministry of Education, Ministry of Health and Welfare, and Korean Center for Disease Control and Prevention. Heated tobacco product use was used as a main independent variable and suicide-related behaviors such as suicidal ideation, planning, and attempts were applied as dependent variables. Out of 60,100 students, 57,303 responded. Results: HTP use significantly increased the odds of a suicide attempt and suicide planning among adolescents. After controlling for confounders, when comparing 'current HTP users' with 'never HTP users', the adjusted odds ratio (OR) was 1.78 (95% confidence interval (CI): 1.38-2.30) for suicide attempts among adolescents. After controlling the confounders, comparing 'current HTP users' with 'never HTP users', the adjusted OR was 1.36 (95% CI: 1.06-1.73) for suicide planning among adolescents. For sadness/despair among adolescents, when comparing 'current HTP users' with 'never HTP users', the adjusted OR was 1.29 (95% CI: 1.11-1.50). However, HTP use had no significant association with suicidal ideation among adolescents. Conclusions: Current HTP users were more likely to attempt to commit suicide, and more likely to plan to commit suicide than never HTP users among adolescents. These results may be useful in developing a scientific basis for designing suicide prevention programs targeting adolescents.